10 CFR 34.61 - Records of the specific license for industrial radiography.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 1 2012-01-01 2012-01-01 false Records of the specific license for industrial radiography. 34.61 Section 34.61 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Recordkeeping Requirements § 34.61...

10 CFR 34.61 - Records of the specific license for industrial radiography.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Records of the specific license for industrial radiography. 34.61 Section 34.61 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Recordkeeping Requirements § 34.61...

Applications of Neutron Radiography for the Nuclear Power Industry

NASA Astrophysics Data System (ADS)

Craft, Aaron E.; Barton, John P.

The World Conference on Neutron Radiography (WCNR) and International Topical Meeting on Neutron Radiography (ITMNR) series have been running over 35 years. The most recent event, ITMNR-8, focused on industrial applications and was the first time this series was hosted in China. In China, more than twenty new nuclear power plants are under construction and plans have been announced to increase the nuclear capacity by a factor of three within fifteen years. There are additional prospects in many other nations. Neutron tests were vital during previous developments of materials and components for nuclear power applications, as reported in the WCNR and ITMNR conference series. For example a majority of the 140 papers in the Proceedings of the First WCNR are for the benefit of the nuclear power industry. Many of those techniques are being utilized and advanced to the present time. Neutron radiography of irradiated nuclear fuel provides more comprehensive information about the internal condition of irradiated nuclear fuel than any other non-destructive technique to date. Applications include examination of nuclear waste, nuclear fuels, cladding, control elements, and other critical components. In this paper, applications of neutron radiography techniques developed and applied internationally for the nuclear power industry since the earliest years are reviewed, and the question is asked whether neutron test techniques, in general, can be of value in development of the present and future generations of nuclear power plants world-wide.

INDUSTRIAL RADIOGRAPHY COURSE, INSTRUCTORS' GUIDE. VOLUME 2.

ERIC Educational Resources Information Center

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

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

Applications of neutron radiography for the nuclear power industry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Craft, Aaron E.; Barton, John P.

The World Conference on Neutron Radiography (WCNR) and International Topical Meeting on Neutron Radiography (ITMNR) series have been running over 35 years. The most recent event, ITMNR-8, focused on industrial applications and was the first time this series was hosted in China. In China, more than twenty new nuclear power plants are in construction and plans have been announced to increase the nuclear capacity further by a factor of three within fifteen years. There are additional prospects in many other nations. Neutron tests were vital during previous developments of materials and components for nuclear power applications, as reported in thismore » conference series. For example a majority of the 140 papers in the Proceedings of the First WCNR are for the benefit of the nuclear power industry. Included are reviews of the diverse techniques being applied in Europe, Japan, the United States, and at many other centers. Many of those techniques are being utilized and advanced to the present time. Neutron radiography of irradiated nuclear fuel provides more comprehensive information about the internal condition of irradiated nuclear fuel than any other non-destructive technique to date. Applications include examination of nuclear waste, nuclear fuels, cladding, control elements, and other critical components. In this paper, the techniques developed and applied internationally for the nuclear power industry since the earliest years are reviewed, and the question is asked whether neutron test techniques can be of value in development of the present and future generations of nuclear power plants world-wide.« less

Understanding the Challenges in the Transition from Film Radiography in the Nuclear Power Industry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meyer, Ryan M.; Ramuhalli, Pradeep; Moran, Traci L.

2012-09-01

Nondestructive examination (NDE) applications in the nuclear power industry using film radiography are shrinking due to the advent of modern digital imaging technologies and advances in alternative inspection methods that do not present an ionizing radiation hazard. Technologies that are used routinely in the medical industry for patient diagnosis are being adapted to industrial NDE applications including the detection and characterization of defects in welds. From the user perspective, non-film inspection techniques provide several advantages over film techniques. It is anticipated that the shift away from the application of film radiography in the nuclear power industry represents an irreversible trend.more » The U.S. Nuclear Regulatory Commission (NRC) has noted this trend in the U.S. nuclear power industry and will be working to ensure that the effectiveness and reliability of component inspections is not compromised by this transition. Currently, specific concerns are associated with 1) obtaining a fundamental understanding of how inspection effectiveness and reliability may be impacted by this transition and 2) ensuring training standards and qualifications remain compatible with modern industrial radiographic practice. This paper discusses recent trends in industrial radiography and assesses their advantages and disadvantages from the perspective of nuclear power plant component inspections.« less

An industrial radiography exposure device based on measurement of transmitted gamma-ray intensity

NASA Astrophysics Data System (ADS)

Polee, C.; Chankow, N.; Srisatit, S.; Thong-Aram, D.

2015-05-01

In film radiography, underexposure and overexposure may happen particularly when lacking information of specimen material and hollowness. This paper describes a method and a device for determining exposure in industrial gamma-ray radiography based on quick measurement of transmitted gamma-ray intensity with a small detector. Application software was developed for Android mobile phone to remotely control the device and to display counting data via Bluetooth communication. Prior to film exposure, the device is placed behind a specimen to measure transmitted intensity which is inversely proportional to the exposure. Unlike in using the conventional exposure curve, correction factors for source decay, source-to- film distance, specimen thickness and kind of material are not needed. The developed technique and device make radiographic process economic, convenient and more reliable.

Safety and security of radioactive sources in industrial radiography in Bangladesh

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mollah, A. S.; Nazrul, M. Abdullah

2013-07-01

Malicious use of radioactive sources can involve dispersal of that material through an explosive device. There has been recognition of the threat posed by the potential malicious misuse of NDT radioactive source by terrorists. The dispersal of radioactive material using conventional explosives, referred to as a 'dirty bomb', could create considerable panic, disruption and area access denial in an urban environment. However, as it is still a relatively new topic among regulators, users, and transport and storage operators worldwide, international assistance and cooperation in developing the necessary regulatory and security infrastructure is required. The most important action in reducing themore » risk of radiological terrorism is to increase the security of radioactive sources. This paper presents safety and security considerations for the transport and site storage of the industrial radiography sources as per national regulations entitled 'Nuclear Safety and Radiation Control Rules-1997'.The main emphasis was put on the stages of some safety and security actions in order to prevent theft, sabotage or other malicious acts during the transport of the packages. As a conclusion it must be mentioned that both safety and security considerations are very important aspects that must be taking in account for the transport and site storage of radioactive sources used in the practice of industrial radiography. (authors)« less

Promoting the safety performance of industrial radiography using a quantitative assessment system.

PubMed

Kardan, M R; Mianji, F A; Rastkhah, N; Babakhani, A; Azad, S Borhan

2006-12-01

The increasing number of industrial radiographers and their considerable occupational exposure has been one of the main concerns of the Iran Nuclear Regulatory Authority (INRA) in recent years. In 2002, a quantitative system of evaluating the safety performance of licensees and a complementary enforcement system was introduced by the National Radiation Protection Department (NRPD). Each parameter of the practice is given a weighting factor according to its importance to safety. Assessment of the licensees is done quantitatively by summing up their scores using prepared tables. Implementing this system of evaluation showed a considerable decrease in deficiencies in the various centres. Tables are updated regularly as a result of findings during the inspections. This system is used in addition to enforcement to promote safety performance and to increase the culture of safety in industrial radiography.

Dose estimation to eye lens of industrial gamma radiography workers using the Monte Carlo method.

PubMed

de Lima, Alexandre Roza; Hunt, John Graham; Da Silva, Francisco Cesar Augusto

2017-12-01

The ICRP Statement on Tissue Reactions (2011), based on epidemiological evidence, recommended a reduction for the eye lens equivalent dose limit from 150 to 20 mSv per year. This paper presents mainly the dose estimations received by industrial gamma radiography workers, during planned or accidental exposure to the eye lens, Hp(10) and effective dose. A Brazilian Visual Monte Carlo Dose Calculation program was used and two relevant scenarios were considered. For the planned exposure situation, twelve radiographic exposures per day for 250 days per year, which leads to a direct exposure of 10 h per year, were considered. The simulation was carried out using a 192 Ir source with 1.0 TBq of activity; a source/operator distance between 5 and 10 m and placed at heights of 0.02 m, 1 m and 2 m, and an exposure time of 12 s. Using a standard height of 1 m, the eye lens doses were estimated as being between 16.3 and 60.3 mGy per year. For the accidental exposure situation, the same radionuclide and activity were used, but in this case the doses were calculated with and without a collimator. The heights above ground considered were 1.0 m, 1.5 m and 2.0 m; the source/operator distance was 40 cm, and the exposure time 74 s. The eye lens doses at 1.5 m were 12.3 and 0.28 mGy without and with a collimator, respectively. The conclusions were that: (1) the estimated doses show that the 20 mSv annual limit for eye lens equivalent dose can directly impact industrial gamma radiography activities, mainly in industries with high number of radiographic exposures per year; (2) the risk of lens opacity has a low probability for a single accident, but depending on the number of accidental exposures and the dose levels found in planned exposures, the threshold dose can easily be exceeded during the professional career of an industrial radiography operator, and; (3) in a first approximation, Hp(10) can be used to estimate the equivalent dose to the eye lens.

Videoscopic assessment of the maintenance status of gamma radiography exposure containers employed in Brazil.

PubMed

Candeias, J P; Estrada, J J S; Pinho, A S; D'Avila, R L; Ramalho, A T

2007-03-01

Industrial radiography is the most frequent method of non-destructive testing (NDT) used by Brazilian industrial facilities for investigating the material integrity of a test object. In Brazil, industrial radiography employs around 220 x-ray and 290 gamma radiography machines. About 90% of the latter uses iridium ((192)Ir) sources. The large majority of (192)Ir projectors in operation in Brazil have been in continuous usage for more than 25 years, which means that they are old and worn-out. Usually the majority of accidents concerning gamma radiography occur during the return of the source into the exposure container. Poor maintenance or imperfections of the internal channel of the exposure container can lead to accidental source exposure. In the present work the internal tube of 65 gamma machines from nine Brazilian companies that render gamma radiography services were analysed using an industrial videoscope. The internal images from the projectors were compared with the internal image of an apparatus that had never been used, i.e. has never received a radioactive source. From the 65 machines evaluated, nine showed irregularities of the internal tube. It was also observed that each company follows a different methodology for the maintenance and lubrication of the exposure containers and drive cables.

Unified Database for Rejected Image Analysis Across Multiple Vendors in Radiography.

PubMed

Little, Kevin J; Reiser, Ingrid; Liu, Lili; Kinsey, Tiffany; Sánchez, Adrian A; Haas, Kateland; Mallory, Florence; Froman, Carmen; Lu, Zheng Feng

2017-02-01

Reject rate analysis has been part of radiography departments' quality control since the days of screen-film radiography. In the era of digital radiography, one might expect that reject rate analysis is easily facilitated because of readily available information produced by the modality during the examination procedure. Unfortunately, this is not always the case. The lack of an industry standard and the wide variety of system log entries and formats have made it difficult to implement a robust multivendor reject analysis program, and logs do not always include all relevant information. The increased use of digital detectors exacerbates this problem because of higher reject rates associated with digital radiography compared with computed radiography. In this article, the authors report on the development of a unified database for vendor-neutral reject analysis across multiple sites within an academic institution and share their experience from a team-based approach to reduce reject rates. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

Industrial Radiography Manual.

ERIC Educational Resources Information Center

Richardson, Harry D.

This text was developed for use by students in an 80-hour course for industrial radiographers. Chapter headings are: (1) The Structure of Matter, (2) Radiation and Radiation Machines, (3) Nuclear Reactions and Radioisotopes, (4) Interaction of Radiation with Matter, (5) Radiation Detection and Measurement, (6) The Nature and Consequences of…

A comprehensive dose assessment of irradiated hand by iridium-192 source in industrial radiography.

PubMed

Hosseini Pooya, S M; Dashtipour, M R; Paydar, R; Mianji, F; Pourshahab, B

2017-09-01

Among the various incidents in industrial radiography, inadvertent handling of sources by hands is one of the most frequent incidents in which some parts of the hands may be locally exposed to high doses. An accurate assessment of extremity dose assists medical doctors in selecting appropriate treatments, preventing the injury expansion in the region. In this study, a phantom was designed to simulate a fisted hand of a radiographer when the worker holds a radioactive source in their hands. The local doses were measured using implanted TLDs in the phantom at different distances from a source. Furthermore, skin dose distribution was measured by Gaf-chromic films in the palm region of the phantom. The reliability of the measurements has been studied via analytical as well as Monte-Carlo simulation methods. The results showed that the new phantom design can be used reliably in extremity dose assessments, particularly at the points next to the source.

Digital Radiography Using Digital Detector Arrays Fulfills Critical Applications for Offshore Pipelines

NASA Astrophysics Data System (ADS)

Moreira, EdsonVasques; Barbosa Rabello, JoséMaurício; Pereira, MarcelodosSantos; Lopes, RicardoTadeu; Zscherpel, Uwe

2010-12-01

Digital radiography in the inspection of welded pipes to be installed under deep water offshore gas and oil pipelines, like a presalt in Brazil, in the paper has been investigated. The aim is to use digital radiography for nondestructive testing of welds as it is already in use in the medical, aerospace, security, automotive, and petrochemical sectors. Among the current options, the DDA (Digital Detector Array) is considered as one of the best solutions to replace industrial films, as well as to increase the sensitivity to reduce the inspection cycle time. This paper shows the results of this new technique, comparing it to radiography with industrial films systems. In this paper, 20 test specimens of longitudinal welded pipe joints, specially prepared with artificial defects like cracks, lack of fusion, lack of penetration, and porosities and slag inclusions with varying dimensions and in 06 different base metal wall thicknesses, were tested and a comparison of the techniques was made. These experiments verified the purposed rules for parameter definitions and selections to control the required digital radiographic image quality as described in the draft international standard ISO/DIS 10893-7. This draft is first standard establishing the parameters for digital radiography on weld seam of welded steel pipes for pressure purposes to be used on gas and oil pipelines.

8. VIEW OF RADIOGRAPHY EQUIPMENT, TEST METHODS INCLUDED RADIOGRAPHY AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. VIEW OF RADIOGRAPHY EQUIPMENT, TEST METHODS INCLUDED RADIOGRAPHY AND BETA BACKSCATTERING. (7/13/56) - Rocky Flats Plant, Non-Nuclear Production Facility, South of Cottonwood Avenue, west of Seventh Avenue & east of Building 460, Golden, Jefferson County, CO

Industrial Radiography Instructor's Guide.

ERIC Educational Resources Information Center

Richardson, Harry D.

The curriculum guide was developed for teacher use in an 80-hour course for industrial radiographers. The units include: (1) The Structure of Matter and Radiation, (2) Nuclear Reactions and Radioisotopes, (3) The Nature and Consequences of Radiation Exposure, (4) Radiation Attenuation, (5) Absorption of Radiation, (6) Radiation Detection and…

X-ray digital industrial radiography (DIR) for local liquid velocity (VLL) measurement in trickle bed reactors (TBRs): Validation of the technique

NASA Astrophysics Data System (ADS)

Mohd Salleh, Khairul Anuar; Rahman, Mohd Fitri Abdul; Lee, Hyoung Koo; Al Dahhan, Muthanna H.

2014-06-01

Local liquid velocity measurements in Trickle Bed Reactors (TBRs) are one of the essential components in its hydrodynamic studies. These measurements are used to effectively determine a reactor's operating condition. This study was conducted to validate a newly developed technique that combines Digital Industrial Radiography (DIR) with Particle Tracking Velocimetry (PTV) to measure the Local Liquid Velocity (VLL) inside TBRs. Three millimeter-sized Expanded Polystyrene (EPS) beads were used as packing material. Three validation procedures were designed to test the newly developed technique. All procedures and statistical approaches provided strong evidence that the technique can be used to measure the VLL within TBRs.

Neutron Radiography and Computed Tomography at Oak Ridge National Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raine, Dudley A. III; Hubbard, Camden R.; Whaley, Paul M.

1997-12-31

The capability to perform neutron radiography and computed tomography is being developed at Oak Ridge National Laboratory. The facility will be located at the High Flux Isotope Reactor (HFIR), which has the highest steady state neutron flux of any reactor in the world. The Monte Carlo N-Particle transport code (MCNP), versions 4A and 4B, has been used extensively in the design phase of the facility to predict and optimize the operating characteristics, and to ensure the safety of personnel working in and around the blockhouse. Neutrons are quite penetrating in most engineering materials and can be useful to detect internalmore » flaws and features. Hydrogen atoms, such as in a hydrocarbon fuel, lubricant or a metal hydride, are relatively opaque to neutron transmission. Thus, neutron based tomography or radiography is ideal to image their presence. The source flux also provides unparalleled flexibility for future upgrades, including real time radiography where dynamic processes can be observed. A novel tomography detector has been designed using optical fibers and digital technology to provide a large dynamic range for reconstructions. Film radiography is also available for high resolution imaging applications. This paper summarizes the results of the design phase of this facility and the potential benefits to science and industry.« less

Student Incivility in Radiography Education.

PubMed

Clark, Kevin R

2017-07-01

To examine student incivility in radiography classrooms by exploring the prevalence of uncivil behaviors along with the classroom management strategies educators use to manage and prevent classroom disruptions. A survey was designed to collect data on the severity and frequency of uncivil student behaviors, classroom management strategies used to address minor and major behavioral issues, and techniques to prevent student incivility. The participants were educators in radiography programs accredited by the Joint Review Committee on Education in Radiologic Technology. Findings indicated that severe uncivil student behaviors in radiography classrooms do not occur as often as behaviors classified as less severe. Radiography educators in this study used a variety of strategies and techniques to manage and prevent student incivility; however, radiography educators who received formal training in classroom management reported fewer incidents of student incivility than those who had not received formal training. The participants in this study took a proactive approach to addressing severe behavioral issues in the classroom. Many radiography educators transition from the clinical environment to the classroom setting with little to no formal training in classroom management. Radiography educators are encouraged to attend formal training sessions to learn how to manage the higher education classroom effectively. Student incivility is present in radiography classrooms. This study provides a foundation for future research on incivility. ©2017 American Society of Radiologic Technologists.

Characterization of mono-ethylene-glycol based industrial polyurethanes samples by fast-neutron radiography and neutron tomography

NASA Astrophysics Data System (ADS)

Rogante, Massimo; Söllradl, Stefan

2016-09-01

A complicated structural organization of polyurethanes may have a strong influence on the materials functional properties. Under particular conditions such as mechanical and thermal loading and aging, it leads to the material degradation, even in fresh-prepared bulk polymers and especially if defects are present in the material. Unwanted bubbles can be observed, which form during the expansion of the mixture during its chemical reaction and remain present in the final product. These macro-, micro- and nano-bubbles influence the material's performance. In this work, neutron radiography and tomography have been adopted to characterize at a macro-scale level the bulk of commercially available polyurethane samples, obtained from dissimilar- mixture ratios with different densities and branching levels as well as from different zones of the production mould. The characterisation allowed an estimation of the different dense materials - as they are used, e.g., in soles of shoes - as well as the invisible defects like pores and cracks, responsible for the materials fracture by mechanical loading. The obtained information are expected to be useful for various industrial sectors such as automotive and footwear industry. It will be completed by applying SANS, which has already proved to characterize the microstructure of the bulk-polymer with respect to nano-pores, micro-cracks and their arrangement in the polymer matrix.

Comparison of computed radiography and conventional radiography in detection of small volume pneumoperitoneum.

PubMed

Marolf, Angela; Blaik, Margaret; Ackerman, Norman; Watson, Elizabeth; Gibson, Nicole; Thompson, Margret

2008-01-01

The role of digital imaging is increasing as these systems are becoming more affordable and accessible. Advantages of computed radiography compared with conventional film/screen combinations include improved contrast resolution and postprocessing capabilities. Computed radiography's spatial resolution is inferior to conventional radiography; however, this limitation is considered clinically insignificant. This study prospectively compared digital imaging and conventional radiography in detecting small volume pneumoperitoneum. Twenty cadaver dogs (15-30 kg) were injected with 0.25, 0.25, and 0.5 ml for 1 ml total of air intra-abdominally, and radiographed sequentially using computed and conventional radiographic technologies. Three radiologists independently evaluated the images, and receiver operating curve (ROC) analysis compared the two imaging modalities. There was no statistical difference between computed and conventional radiography in detecting free abdominal air, but overall computed radiography was relatively more sensitive based on ROC analysis. Computed radiographic images consistently and significantly demonstrated a minimal amount of 0.5 ml of free air based on ROC analysis. However, no minimal air amount was consistently or significantly detected with conventional film. Readers were more likely to detect free air on lateral computed images than the other projections, with no significant increased sensitivity between film/screen projections. Further studies are indicated to determine the differences or lack thereof between various digital imaging systems and conventional film/screen systems.

X-ray digital industrial radiography (DIR) for local liquid velocity (V(LL)) measurement in trickle bed reactors (TBRs): validation of the technique.

PubMed

Mohd Salleh, Khairul Anuar; Rahman, Mohd Fitri Abdul; Lee, Hyoung Koo; Al Dahhan, Muthanna H

2014-06-01

Local liquid velocity measurements in Trickle Bed Reactors (TBRs) are one of the essential components in its hydrodynamic studies. These measurements are used to effectively determine a reactor's operating condition. This study was conducted to validate a newly developed technique that combines Digital Industrial Radiography (DIR) with Particle Tracking Velocimetry (PTV) to measure the Local Liquid Velocity (V(LL)) inside TBRs. Three millimeter-sized Expanded Polystyrene (EPS) beads were used as packing material. Three validation procedures were designed to test the newly developed technique. All procedures and statistical approaches provided strong evidence that the technique can be used to measure the V(LL) within TBRs.

10 CFR 34.41 - Conducting industrial radiographic operations.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 1 2014-01-01 2014-01-01 false Conducting industrial radiographic operations. 34.41 Section 34.41 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Radiation Safety Requirements § 34.41...

10 CFR 34.41 - Conducting industrial radiographic operations.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 1 2011-01-01 2011-01-01 false Conducting industrial radiographic operations. 34.41 Section 34.41 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Radiation Safety Requirements § 34.41...

10 CFR 34.41 - Conducting industrial radiographic operations.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 1 2012-01-01 2012-01-01 false Conducting industrial radiographic operations. 34.41 Section 34.41 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Radiation Safety Requirements § 34.41...

10 CFR 34.41 - Conducting industrial radiographic operations.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Conducting industrial radiographic operations. 34.41 Section 34.41 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Radiation Safety Requirements § 34.41...

10 CFR 34.41 - Conducting industrial radiographic operations.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 1 2013-01-01 2013-01-01 false Conducting industrial radiographic operations. 34.41 Section 34.41 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Radiation Safety Requirements § 34.41...

Problems associated with digital luminescence radiography in the neonate and young infant. Problems with digital radiography.

PubMed

Arthur, R J; Pease, J N

1992-01-01

An evaluation of the Siemens Digiscan has been undertaken to determine whether digital luminescence radiography (DLR) could replace conventional radiography in the examination of the neonate and young infant. Whilst the overall image quality of the digital radiograph was consistently higher than for conventional radiography the difference was less marked than we had expected. Furthermore, the potential for reduction in radiation dose by reducing the repeat rate due to incorrect exposure was limited. The potential advantages of DLR have been critically examined in relationship to neonatal radiography and a number of problems encountered during the evaluation have been highlighted.

The Image Gently pediatric digital radiography safety checklist: tools for improving pediatric radiography.

PubMed

John, Susan D; Moore, Quentin T; Herrmann, Tracy; Don, Steven; Powers, Kevin; Smith, Susan N; Morrison, Greg; Charkot, Ellen; Mills, Thalia T; Rutz, Lois; Goske, Marilyn J

2013-10-01

Transition from film-screen to digital radiography requires changes in radiographic technique and workflow processes to ensure that the minimum radiation exposure is used while maintaining diagnostic image quality. Checklists have been demonstrated to be useful tools for decreasing errors and improving safety in several areas, including commercial aviation and surgical procedures. The Image Gently campaign, through a competitive grant from the FDA, developed a checklist for technologists to use during the performance of digital radiography in pediatric patients. The checklist outlines the critical steps in digital radiography workflow, with an emphasis on steps that affect radiation exposure and image quality. The checklist and its accompanying implementation manual and practice quality improvement project are open source and downloadable at www.imagegently.org. The authors describe the process of developing and testing the checklist and offer suggestions for using the checklist to minimize radiation exposure to children during radiography. Copyright © 2013 American College of Radiology. All rights reserved.

Image Acquisition and Quality in Digital Radiography.

PubMed

Alexander, Shannon

2016-09-01

Medical imaging has undergone dramatic changes and technological breakthroughs since the introduction of digital radiography. This article presents information on the development of digital radiography and types of digital radiography systems. Aspects of image quality and radiation exposure control are highlighted as well. In addition, the article includes related workplace changes and medicolegal considerations in the digital radiography environment. ©2016 American Society of Radiologic Technologists.

Clinical feline dental radiography.

PubMed

Lemmons, Matthew

2013-05-01

Dental radiography is a necessary diagnostic modality in small animal practice. It is not possible to accurately assess and diagnose tooth resorption, periodontal disease, endodontic disease, neoplasia and injury without it. Dental radiography is also necessary for treatment and assessment of the patient postoperatively. Copyright © 2013 Elsevier Inc. All rights reserved.

Radiography of the Paranasal Sinuses

MedlinePlus

... your back or over your lap. This head. Radiography of the paranasal sinuses apron will protect your ... face, especially when lowering his or her head. Radiography of sitting and others while you are standing. ...

INDUSTRIAL RADIOGRAPHY COURSE, INSTRUCTOR'S GUIDE, VOLUME 1.

ERIC Educational Resources Information Center

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

THE PURPOSE OF THE GUIDE IS TO GIVE MAXIMUM ASSISTANCE TO INSTRUCTORS IN PLANNING THE TRAINING OF LICENSED INDUSTRIAL RADIOGRAPHERS. IT WAS DEVELOPED BY THE ENGINEERING EXTENSION SERVICE, TEXAS AGRICULTURAL AND MECHANICAL UNIVERSITY, COLLEGE STATION, TEXAS. THE 21 UNITS INCLUDE (1) INDUSTRIAL APPLICATIONS, (2) NONDESTRUCTIVE TESTING METHODS, (3)…

Dental radiography in New Zealand: digital versus film.

PubMed

Ting, N A; Broadbent, J M; Duncan, W J

2013-09-01

Digital x-ray systems offer advantages over conventional film systems, yet many dentists have not adopted digital technology. To assess New Zealand dental practitioners' use of--and preferences for--dental radiography systems. Cross-sectional survey. General and specialist dental practice. Postal questionnaire survey of a sample of 770 dentists (520 randomly selected general dental practitioners and all 250 specialists) listed in the 2012 NZ Dental Council Register. Type of radiography systems used by dentists. Dentists' experiences and opinions of conventional film and digital radiography. The participation rate was 55.2%. Digital radiography systems were used by 58.0% of participating dentists, most commonly among those aged 31-40 years. Users of digital radiography tended to report greater satisfaction with their radiography systems than users conventional films. Two-thirds of film users were interested in switching to digital radiography in the near future. Reasons given by conventional film users for not using digital radiography included cost, difficulty in integrating with other software systems, concern about potential technical errors, and the size and nature of the intra-oral sensors. Many dental practitioners have still not adopted digital radiography, yet its users are more satisfied with their radiography systems than are conventional film users. The latter may find changing to a digital system to be satisfying and rewarding.

Axial Tomography from Digitized Real Time Radiography

DOE R&D Accomplishments Database

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

1985-01-18

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

A Neutron Radiography System for Field Use

DTIC Science & Technology

1989-06-01

provoked a major renewal of interest in neutron radiography because it promises to bring neutron radiography to the workplace , a convenience provided...II I~F I C II i IiH i ii MTL TR 89-52 I-AD A NEUTRON RADIOGRAPHY SYSTEM N FOR FIELD USE e~m JOHN J. ANTAL and ALFRED S. MAROTTA, and LOUIS J. FARESE...COVERED A NEUTRON RADIOGRAPHY SYSTEM FOR FIELD USE Final Report 6. PERFORMING OR1. REPORT NUMBER 7. AUTHOR(s) S. CONTRACT OR GRANT NUMBER(s) John J

Taiwan: improving radiography through application of Six Sigma techniques.

PubMed

Chen, Yan-Kwang; Lin, Jerry; Chang, Cheng-Chang

2005-01-01

The healthcare industry has shown significant recent growth potential in Taiwan. Associated financial problems have grown considerably since 1995, when national health insurance was implemented. Taiwan's healthcare bureau began to change the primary quantity-based healthcare expense payment method to a case-based payment model. Hospitals are now challenged to minimize healthcare waste. This article examines the application of manufacturing-based Six Sigma methods to an X-ray radiography improvement project to reduce the defect ratio of films for a teaching hospital in Taiwan. It was determined that (1) analysis of customer satisfaction data helped the Six Sigma improvement team identify critical quality elements; (2) the Six Sigma Level in this healthcare project is Lower than that in the manufacturing industry; (3) the improvement opportunity and the time required for the project had a direct correlation to the importance ascribed to the project and the cooperation received; and (4) process change can be made more quickly in the healthcare industry than in the manufacturing industry.

Artefacts found in computed radiography.

PubMed

Cesar, L J; Schueler, B A; Zink, F E; Daly, T R; Taubel, J P; Jorgenson, L L

2001-02-01

Artefacts on radiographic images are distracting and may compromise accurate diagnosis. Although most artefacts that occur in conventional radiography have become familiar, computed radiography (CR) systems produce artefacts that differ from those found in conventional radiography. We have encountered a variety of artefacts in CR images that were produced from four different models plate reader. These artefacts have been identified and traced to the imaging plate, plate reader, image processing software or laser printer or to operator error. Understanding the potential sources of CR artefacts will aid in identifying and resolving problems quickly and help prevent future occurrences.

Using athletic training clinical education standards in radiography.

PubMed

Giordano, Shelley; Harris, Katherine

2012-01-01

The selection of clinical education sites for radiography students is based on availability, access to radiographic examinations, and appropriate student-to-technologist ratio. Radiography program directors are not required to evaluate sites based on their educational validity (eg, the clinical instructor's knowledge of basic teaching and learning principles, how well the site communicates with the program, or the clinical instructor's involvement in professional organizations). The purpose of this study was to determine if a set of 12 clinical education standards used in athletic training would be applicable and beneficial to radiography program directors when selecting clinical sites for students. A survey concerning the applicability of the athletic training standards to radiography site selection was completed by 270 directors of radiography programs accredited by the Joint Review Committee on Education in Radiologic Technology. The survey results indicated the athletic training clinical education standards were considered applicable to the selection of clinical sites for radiography students and would be beneficial to radiography program directors when selecting sites.

WE-G-209-01: Digital Radiography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schueler, B.

Digital radiography, CT, PET, and MR are complicated imaging modalities which are composed of many hardware and software components. These components work together in a highly coordinated chain of events with the intent to produce high quality images. Acquisition, processing and reconstruction of data must occur in a precise way for optimum image quality to be achieved. Any error or unexpected event in the entire process can produce unwanted pixel intensities in the final images which may contribute to visible image artifacts. The diagnostic imaging physicist is uniquely qualified to investigate and contribute to resolution of image artifacts. This coursemore » will teach the participant to identify common artifacts found clinically in digital radiography, CT, PET, and MR, to determine the causes of artifacts, and to make recommendations for how to resolve artifacts. Learning Objectives: Identify common artifacts found clinically in digital radiography, CT, PET and MR. Determine causes of various clinical artifacts from digital radiography, CT, PET and MR. Describe how to resolve various clinical artifacts from digital radiography, CT, PET and MR.« less

Particle Beam Radiography

NASA Astrophysics Data System (ADS)

Peach, Ken; Ekdahl, Carl

2014-02-01

Particle beam radiography, which uses a variety of particle probes (neutrons, protons, electrons, gammas and potentially other particles) to study the structure of materials and objects noninvasively, is reviewed, largely from an accelerator perspective, although the use of cosmic rays (mainly muons but potentially also high-energy neutrinos) is briefly reviewed. Tomography is a form of radiography which uses multiple views to reconstruct a three-dimensional density map of an object. There is a very wide range of applications of radiography and tomography, from medicine to engineering and security, and advances in instrumentation, specifically the development of electronic detectors, allow rapid analysis of the resultant radiographs. Flash radiography is a diagnostic technique for large high-explosive-driven hydrodynamic experiments that is used at many laboratories. The bremsstrahlung radiation pulse from an intense relativistic electron beam incident onto a high-Z target is the source of these radiographs. The challenge is to provide radiation sources intense enough to penetrate hundreds of g/cm2 of material, in pulses short enough to stop the motion of high-speed hydrodynamic shocks, and with source spots small enough to resolve fine details. The challenge has been met with a wide variety of accelerator technologies, including pulsed-power-driven diodes, air-core pulsed betatrons and high-current linear induction accelerators. Accelerator technology has also evolved to accommodate the experimenters' continuing quest for multiple images in time and space. Linear induction accelerators have had a major role in these advances, especially in providing multiple-time radiographs of the largest hydrodynamic experiments.

Transitioning to digital radiography.

PubMed

Drost, Wm Tod

2011-04-01

To describe the different forms of digital radiography (DR), image file formats, supporting equipment and services required for DR, storage of digital images, and teleradiology. Purchasing a DR system is a major investment for a veterinary practice. Types of DR systems include computed radiography, charge coupled devices, and direct or indirect DR. Comparison of workflow for analog and DR is presented. On the surface, switching to DR involves the purchase of DR acquisition hardware. The X-ray machine, table and grids used in analog radiography are the same for DR. Realistically, a considerable infrastructure supports the image acquisition hardware. This infrastructure includes monitors, computer workstations, a robust computer network and internet connection, a plan for storage and back up of images, and service contracts. Advantages of DR compared with analog radiography include improved image quality (when used properly), ease of use (more forgiving to the errors of radiographic technique), speed of making a complete study (important for critically ill patients), fewer repeat radiographs, less time looking for imaging studies, less physical storage space, and the ability to easily send images for consultation. With an understanding of the infrastructure requirements, capabilities and limitations of DR, an informed veterinary practice should be better able to make a sound decision about transitioning to DR. © Veterinary Emergency and Critical Care Society 2011.

Embossed radiography utilizing energy subtraction.

PubMed

Osawa, Akihiro; Watanabe, Manabu; Sato, Eiichi; Matsukiyo, Hiroshi; Enomoto, Toshiyuki; Nagao, Jiro; Abderyim, Purkhet; Aizawa, Katsuo; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Ehara, Shigeru; Sato, Shigehiro; Ogawa, Akira; Onagawa, Jun

2009-01-01

Currently, it is difficult to carry out refraction-contrast radiography by using a conventional X-ray generator. Thus, we developed an embossed radiography system utilizing dual-energy subtraction for decreasing the absorption contrast in unnecessary regions, and the contrast resolution of a target region was increased by use of image-shifting subtraction and a linear-contrast system in a flat panel detector (FPD). The X-ray generator had a 100-microm-focus tube. Energy subtraction was performed at tube voltages of 45 and 65 kV, a tube current of 0.50 mA, and an X-ray exposure time of 5.0 s. A 1.0-mm-thick aluminum filter was used for absorbing low-photon-energy bremsstrahlung X-rays. Embossed radiography was achieved with cohesion imaging by use of the FPD with pixel sizes of 48 x 48 microm, and the shifting dimension of an object in the horizontal direction ranged from 100 to 200 microm. At a shifting distance of 100 mum, the spatial resolutions in the horizontal and vertical directions measured with a lead test chart were both 83 microm. In embossed radiography of non-living animals, we obtained high-contrast embossed images of fine bones, gadolinium oxide particles in the kidney, and coronary arteries approximately 100 microm in diameter.

Toward practical 3D radiography of pipeline girth welds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wassink, Casper, E-mail: casper.wassink@applusrtd.com; Hol, Martijn, E-mail: martijn.hol@applusrtd.com; Flikweert, Arjan, E-mail: martijn.hol@applusrtd.com

2015-03-31

Digital radiography has made its way into in-the-field girth weld testing. With recent generations of detectors and x-ray tubes it is possible to reach the image quality desired in standards as well as the speed of inspection desired to be competitive with film radiography and automated ultrasonic testing. This paper will show the application of these technologies in the RTD Rayscan system. The method for achieving an image quality that complies with or even exceeds prevailing industrial standards will be presented, as well as the application on pipeline girth welds with CRA layers. A next step in development will bemore » to also achieve a measurement of weld flaw height to allow for performing an Engineering Critical Assessment on the weld. This will allow for similar acceptance limits as currently used with Automated Ultrasonic Testing of pipeline girth welds. Although a sufficient sizing accuracy was already demonstrated and qualified in the TomoCAR system, testing in some applications is restricted to time limits. The paper will present some experiments that were performed to achieve flaw height approximation within these time limits.« less

Multi-Institutional Evaluation of Digital Tomosynthesis, Dual-Energy Radiography, and Conventional Chest Radiography for the Detection and Management of Pulmonary Nodules.

PubMed

Dobbins, James T; McAdams, H Page; Sabol, John M; Chakraborty, Dev P; Kazerooni, Ella A; Reddy, Gautham P; Vikgren, Jenny; Båth, Magnus

2017-01-01

Purpose To conduct a multi-institutional, multireader study to compare the performance of digital tomosynthesis, dual-energy (DE) imaging, and conventional chest radiography for pulmonary nodule detection and management. Materials and Methods In this binational, institutional review board-approved, HIPAA-compliant prospective study, 158 subjects (43 subjects with normal findings) were enrolled at four institutions. Informed consent was obtained prior to enrollment. Subjects underwent chest computed tomography (CT) and imaging with conventional chest radiography (posteroanterior and lateral), DE imaging, and tomosynthesis with a flat-panel imaging device. Three experienced thoracic radiologists identified true locations of nodules (n = 516, 3-20-mm diameters) with CT and recommended case management by using Fleischner Society guidelines. Five other radiologists marked nodules and indicated case management by using images from conventional chest radiography, conventional chest radiography plus DE imaging, tomosynthesis, and tomosynthesis plus DE imaging. Sensitivity, specificity, and overall accuracy were measured by using the free-response receiver operating characteristic method and the receiver operating characteristic method for nodule detection and case management, respectively. Results were further analyzed according to nodule diameter categories (3-4 mm, >4 mm to 6 mm, >6 mm to 8 mm, and >8 mm to 20 mm). Results Maximum lesion localization fraction was higher for tomosynthesis than for conventional chest radiography in all nodule size categories (3.55-fold for all nodules, P < .001; 95% confidence interval [CI]: 2.96, 4.15). Case-level sensitivity was higher with tomosynthesis than with conventional chest radiography for all nodules (1.49-fold, P < .001; 95% CI: 1.25, 1.73). Case management decisions showed better overall accuracy with tomosynthesis than with conventional chest radiography, as given by the area under the receiver operating characteristic curve

Laser-Compton photon radiography for nondestructive test of bulk materials

NASA Astrophysics Data System (ADS)

Toyokawa, Hiroyuki; Ohgaki, Hideaki; Kudo, Katshuhisa; Takeda, Naoto; Mikado, Tomohisa; Yamada, Kawakatsu

2001-12-01

Experimental results of transmission photon radiography of bulk materials using the laser-Compton photon beam in the energy range of 2-20 MeV are given. The purpose of this work is to demonstrate the effectiveness and to survey a potential need and a technical limit of the present method for industrial application, such as nondestructive test of bulk materials. Several radiographs of metals, ceramics, and concrete were measured with the present method. Position resolution of the system was measured with using 10 MeV photon beam and slit. It was less than 1 mm.

TREAT neutron-radiography facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harrison, L.J.

1981-01-01

The TREAT reactor was built as a transient irradiation test reactor. By taking advantage of built-in system features, it was possible to add a neutron-radiography facility. This facility has been used over the years to radiograph a wide variety and large number of preirradiated fuel pins in many different configurations. Eight different specimen handling casks weighing up to 54.4 t (60 T) can be accommodated. Thermal, epithermal, and track-etch radiographs have been taken. Neutron-radiography service can be provided for specimens from other reactor facilities, and the capacity for storing preirradiated specimens also exists.

Digital radiography: a survey of pediatric dentists.

PubMed

Russo, Julie M; Russo, James A; Guelmann, Marcio

2006-01-01

The purpose of this study was to: (1) determine the popularity of digital radiography among members of the American Academy of Pediatric Dentistry (AAPD); and (2) report the most common systems in use. An AAPD-approved, voluntary, and anonymous electronic survey was developed and sent to 923 board certified pediatric dentists. Years in practice and in-office x-ray technology (digital or conventional) were inquired about initially. If negative for the use of digital radiography, future consideration for converting to digital radiography was ascertained. For positive responses, more in-depth information was requested. Information on type of system (sensor or phosphor plate), user friendliness, diagnostic ability, patient's comfort, general costs, durability, and parental and overall satisfaction was collected. For most of the questions, a 5-point assessment scale was used. Opportunity for additional comments was provided upon survey completion. Data was analyzed using descriptive statistics. A 32% (296/923) response rate was obtained. Twenty-six percent of practitioners (78/296) implemented digital radiography in their practices, whereas 71% considered future acquisition. Similar distribution for sensor and phosphor plate users was found. Sensor technology was reported to produce faster images, but was less tolerable by young children due to size and thickness. Phosphor plates were considered more children friendly, less expensive, and less durable. Parental satisfaction was very high with great marketing value. Picture quality was comparable to conventional film. Overall, digital radiography users would recommend it to other pediatric dentists. Digital radiography is not yet popular among pediatric dentists. Cost reduction and technology advancement may enhance utilization.

Simultaneous wood and metal particle detection on dark-field radiography.

PubMed

Braig, Eva-Maria; Birnbacher, Lorenz; Schaff, Florian; Gromann, Lukas; Fingerle, Alexander; Herzen, Julia; Rummeny, Ernst; Noël, Peter; Pfeiffer, Franz; Muenzel, Daniela

2018-01-01

Currently, the detection of retained wood is a frequent but challenging task in emergency care. The purpose of this study is to demonstrate improved foreign-body detection with the novel approach of preclinical X-ray dark-field radiography. At a preclinical dark-field x-ray radiography, setup resolution and sensitivity for simultaneous detection of wooden and metallic particles have been evaluated in a phantom study. A clinical setting has been simulated with a formalin fixated human hand where different typical foreign-body materials have been inserted. Signal-to-noise ratios (SNR) have been determined for all test objects. On the phantom, the SNR value for wood in the dark-field channel was strongly improved by a factor 6 compared to conventional radiography and even compared to the SNR of an aluminium structure of the same size in conventional radiography. Splinters of wood < 300 μm in diameter were clearly detected on the dark-field radiography. Dark-field radiography of the formalin-fixated human hand showed a clear signal for wooden particles that could not be identified on conventional radiography. x-ray dark-field radiography enables the simultaneous detection of wooden and metallic particles in the extremities. It has the potential to improve and simplify the current state-of-the-art foreign-body detection.

Multi-Institutional Evaluation of Digital Tomosynthesis, Dual-Energy Radiography, and Conventional Chest Radiography for the Detection and Management of Pulmonary Nodules

PubMed Central

McAdams, H. Page; Sabol, John M.; Chakraborty, Dev P.; Kazerooni, Ella A.; Reddy, Gautham P.; Vikgren, Jenny; Båth, Magnus

2017-01-01

Purpose To conduct a multi-institutional, multireader study to compare the performance of digital tomosynthesis, dual-energy (DE) imaging, and conventional chest radiography for pulmonary nodule detection and management. Materials and Methods In this binational, institutional review board–approved, HIPAA-compliant prospective study, 158 subjects (43 subjects with normal findings) were enrolled at four institutions. Informed consent was obtained prior to enrollment. Subjects underwent chest computed tomography (CT) and imaging with conventional chest radiography (posteroanterior and lateral), DE imaging, and tomosynthesis with a flat-panel imaging device. Three experienced thoracic radiologists identified true locations of nodules (n = 516, 3–20-mm diameters) with CT and recommended case management by using Fleischner Society guidelines. Five other radiologists marked nodules and indicated case management by using images from conventional chest radiography, conventional chest radiography plus DE imaging, tomosynthesis, and tomosynthesis plus DE imaging. Sensitivity, specificity, and overall accuracy were measured by using the free-response receiver operating characteristic method and the receiver operating characteristic method for nodule detection and case management, respectively. Results were further analyzed according to nodule diameter categories (3–4 mm, >4 mm to 6 mm, >6 mm to 8 mm, and >8 mm to 20 mm). Results Maximum lesion localization fraction was higher for tomosynthesis than for conventional chest radiography in all nodule size categories (3.55-fold for all nodules, P < .001; 95% confidence interval [CI]: 2.96, 4.15). Case-level sensitivity was higher with tomosynthesis than with conventional chest radiography for all nodules (1.49-fold, P < .001; 95% CI: 1.25, 1.73). Case management decisions showed better overall accuracy with tomosynthesis than with conventional chest radiography, as given by the area under the receiver operating characteristic

National reference doses for dental cephalometric radiography.

PubMed

Holroyd, J R

2011-12-01

Diagnostic reference levels (DRLs) are an important tool in the optimisation of clinical radiography. Although national DRLs are provided for many diagnostic procedures including dental intra-oral radiography, there are currently no national DRLs set for cephalometric radiography. In the absence of formal national DRLs, the Health Protection Agency (HPA) has previously published National Reference Doses (NRDs) covering a wide range of diagnostic X-ray examinations. The aim of this study was to determine provisional NRDs for cephalometric radiography. Measurements made by the Dental X-ray Protection Service (DXPS) of the HPA, as part of the cephalometric X-ray equipment testing service provided to dentists and dental trade companies throughout the UK, were used to derive provisional NRDs. Dose-area product measurements were made on 42 X-ray sets. Third quartile dose-area product values for adult and child lateral cephalometric radiography were found to be 41 mGy cm² and 25 mGy cm², respectively, with individual measurements ranging from 3 mGy cm² to 108 mGy cm². This report proposes provisional NRDs of 40 mGy cm² and 25 mGy cm² for adult and child lateral cephalometric radiographs, respectively; these doses could be considered by employers when establishing their local DRLs.

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

NASA Astrophysics Data System (ADS)

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

2003-06-01

Main types of photoreceivers 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.

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

NASA Astrophysics Data System (ADS)

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.

Digital radiography in space.

PubMed

Hart, Rob; Campbell, Mark R

2002-06-01

With the permanent habitation of the International Space Station, the planning of longer duration exploration missions, and the possibility of space tourism, it is likely that digital radiography will be needed in the future to support medical care in space. Ultrasound is currently the medical imaging modality of choice for spaceflight. Digital radiography in space is limited because of prohibitive launch costs (in the region of $20,000/kg) that severely restrict the volume, weight, and power requirements of medical care hardware. Technological increases in radiography, a predicted ten-fold decrease in future launch costs, and an increasing clinical need for definitive medical care in space will drive efforts to expand the ability to provide medical care in space including diagnostic imaging. Normal physiological responses to microgravity, in conjunction with the high-risk environment of spaceflight, increase the risk of injury and could imply an extended recovery period for common injuries. The advantages of gravity on Earth, such as the stabilization of patients undergoing radiography and the drainage of fluids, which provide radiographic contrast, are unavailable in space. This creates significant difficulties in patient immobilization and radiographic positioning. Gravity-dependent radiological signs, such as lipohemarthrosis in knee and shoulder trauma, air or fluid levels in pneumoperitoneum, pleural effusion, or bowel obstruction, and the apical pleural edge in pneumothorax become unavailable. Impaired healing processes such as delayed callus formation following fracture will have implications on imaging, and recovery time lines are unknown. The confined nature of spacecraft and the economic impossibility of launching lead-based personal protective equipment present significant challenges to crew radiation safety. A modified, free-floating radiographic C-arm device equipped with a digital detector and utilizing teleradiology support is proposed as a

Assessment of medial elbow laxity by gravity stress radiography: comparison of valgus stress radiography with gravity and a Telos stress device.

PubMed

Harada, Mikio; Takahara, Masatoshi; Maruyama, Masahiro; Nemoto, Tadanobu; Koseki, Kazuhiko; Kato, Yoshihiro

2014-04-01

Valgus instability was reported to be higher with the elbow in 60° of flexion, rather than in 30° of flexion, although there are no studies using valgus stress radiography by gravity (gravity radiography) with the elbow in 60° of flexion. Fifty-seven patients with medial elbow pain participated. For both elbows, valgus stress radiography by use of a Telos device (Telos radiography) and gravity radiography, with the elbow in 60° of flexion, were performed for the assessment of medial elbow laxity. In both radiographs, the medial elbow joint space (MJS) on the affected side was compared with that on the opposite side, and the increase in the MJS on the affected side was assessed. For the Telos radiographs, the mean MJS was 4.7 mm on the affected side and 4.0 mm on the opposite side, with the mean increase in the MJS on the affected side being 0.7 mm. For the gravity radiographs, the mean MJS was 5.0 mm on the affected side and 4.2 mm on the opposite side, with the mean increase in the MJS on the affected side being 0.8 mm. There were significant correlations between the Telos and gravity radiographs in the MJS on the affected side, the MJS on the opposite side, and the increase in the MJS on the affected side (respectively, P < .0001). There was also a high level of intraobserver and interobserver reliability for the assessment of the gravity radiographs. Gravity radiography is useful for assessment of medial elbow laxity, similar to Telos radiography. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

Neutron radiography of irradiated nuclear fuel at Idaho National Laboratory

DOE PAGES

Craft, Aaron E.; Wachs, Daniel M.; Okuniewski, Maria A.; ...

2015-09-10

Neutron radiography of irradiated nuclear fuel provides more comprehensive information about the internal condition of irradiated nuclear fuel than any other non-destructive technique to date. Idaho National Laboratory (INL) has multiple nuclear fuels research and development programs that routinely evaluate irradiated fuels using neutron radiography. The Neutron Radiography reactor (NRAD) sits beneath a shielded hot cell facility where neutron radiography and other evaluation techniques are performed on these highly radioactive objects. The NRAD currently uses the foil-film transfer technique for imaging fuel that is time consuming but provides high spatial resolution. This study describes the NRAD and hot cell facilities,more » the current neutron radiography capabilities available at INL, planned upgrades to the neutron imaging systems, and new facilities being brought online at INL related to neutron imaging.« less

Evaluation of a Noise Reduction Procedure for Chest Radiography

PubMed Central

Fukui, Ryohei; Ishii, Rie; Kodani, Kazuhiko; Kanasaki, Yoshiko; Suyama, Hisashi; Watanabe, Masanari; Nakamoto, Masaki; Fukuoka, Yasushi

2013-01-01

Background The aim of this study was to evaluate the usefulness of noise reduction procedure (NRP), a function in the new image processing for chest radiography. Methods A CXDI-50G Portable Digital Radiography System (Canon) was used for X-ray detection. Image noise was analyzed with a noise power spectrum (NPS) and a burger phantom was used for evaluation of density resolution. The usefulness of NRP was evaluated by chest phantom images and clinical chest radiography. We employed the Bureau of Radiological Health Method for scoring chest images while carrying out our observations. Results NPS through the use of NRP was improved compared with conventional image processing (CIP). The results in image quality showed high-density resolution through the use of NRP, so that chest radiography examination can be performed with a low dose of radiation. Scores were significantly higher than for CIP. Conclusion In this study, use of NRP led to a high evaluation in these so we are able to confirm the usefulness of NRP for clinical chest radiography. PMID:24574577

Comparison of ultrasonography and radiography in diagnosis of rib fractures.

PubMed

Pishbin, Elham; Ahmadi, Koorosh; Foogardi, Molood; Salehi, Maryam; Seilanian Toosi, Farrokh; Rahimi-Movaghar, Vafa

2017-08-01

Rib fractures are the most common skeletal thoracic injuries resulting from blunt chest trauma. Half of the rib fractures are not detected upon a precise physical evaluation and radiographs. Recently ultrasonography (USG) has been investigated to detect rib fractures. But based on literature the usefulness of USG varies widely. This study was conducted to investigate the role of USG in the detection of possible rib fractures in comparison with radiography. In this cross-sectional study, consecutive patients with minor blunt chest trauma and suspected rib fractures presenting in Imam Reza Hospital located in Mashhad-Iran, between April 2013 and October 2013 were assessed by USG and radiography. The radiography was performed in a posteroanterior (PA) chest projection and oblique rib view centered over the area of trauma. The time duration spent in taking USG and radiography were recorded. The prevalence and location of fractures revealed by USG and radiography were compared. Sixty-one suspected patients were assessed. The male to female ratio was 2.4:1 (43 men and 18 women) with a mean ± SD age of (44.3 ± 19.7) years. There were totally 59 rib fractures in 38 (62.3%) patients based on radiography and USG, while 23 (37.7%) patients had no diagnostic evidence of rib lesions. USG revealed 58 rib fractures in 33 (54.1%) of 61 suspected patients and radiographs revealed 32 rib fractures in 20 (32.8%) of 61 patients. A total of 58 (98.3%) rib fractures were detected by USG, whereas oblique rib view and PA chest radiography showed 27 (45.8%) and 24 (40.7%) rib fractures, respectively. The average duration of USG was (12 ± 3) min (range 7-17 min), whereas the duration of radiography was (27 ± 6) min (range 15-37 min). The kappa coefficient showed a low level of agreement between both USG and PA chest radiography (kappa coefficient = 0.28), and between USG and oblique rib view (kappa coefficient = 0.32). USG discloses more fractures than radiography in

Proton Radiography Peers into Metal Solidification

DOE PAGES

Clarke, Amy J.; Imhoff, Seth D.; Gibbs, Paul J.; ...

2013-06-19

Historically, metals are cut up and polished to see the structure and to infer how processing influences the evolution. We can now peer into a metal during processing without destroying it using proton radiography. Understanding the link between processing and structure is important because structure profoundly affects the properties of engineering materials. Synchrotron x-ray radiography has enabled real-time glimpses into metal solidification. However, x-ray energies favor the examination of small volumes and low density metals. In this study, we use high energy proton radiography for the first time to image a large metal volume (>10,000 mm 3) during melting andmore » solidification. We also show complementary x-ray results from a small volume (<1mm 3), bridging four orders of magnitude. In conclusion, real-time imaging will enable efficient process development and the control of the structure evolution to make materials with intended properties; it will also permit the development of experimentally informed, predictive structure and process models.« less

Abdomen X-Ray (Radiography)

MedlinePlus

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

Apparatus for proton radiography

DOEpatents

Martin, Ronald L.

1976-01-01

An apparatus for effecting diagnostic proton radiography of patients in hospitals comprises a source of negative hydrogen ions, a synchrotron for accelerating the negative hydrogen ions to a predetermined energy, a plurality of stations for stripping extraction of a radiography beam of protons, means for sweeping the extracted beam to cover a target, and means for measuring the residual range, residual energy, or percentage transmission of protons that pass through the target. The combination of information identifying the position of the beam with information about particles traversing the subject and the back absorber is performed with the aid of a computer to provide a proton radiograph of the subject. In an alternate embodiment of the invention, a back absorber comprises a plurality of scintillators which are coupled to detectors.

Imaging of Rabbit VX-2 Hepatic Cancer by Cold and Thermal Neutron Radiography

NASA Astrophysics Data System (ADS)

Tsuchiya, Yoshinori; Matsubayashi, Masahito; Takeda, Tohoru; Lwin, Thet Thet; Wu, Jin; Yoneyama, Akio; Matsumura, Akira; Hori, Tomiei; Itai, Yuji

2003-11-01

Neutron radiography is based on differences in neutron mass attenuation coefficients among the elements and is a non-destructive imaging method. To investigate biomedical applications of neutron radiography, imaging of rabbit VX-2 liver cancer was performed using thermal and cold neutron radiography with a neutron imaging plate. Hepatic vessels and VX-2 tumor were clearly observed by neutron radiography, especially by cold neutron imaging. The image contrast of this modality was better than that of absorption-contrast X-ray radiography.

Radiography Student Participation in Professional Organizations.

PubMed

Michael, Kimberly; Tran, Xuan; Keller, Shelby; Sayles, Harlan; Custer, Tanya

2017-09-01

To gather data on educational program requirements for student membership in a state or national professional society, organization, or association. A 10-question online survey about student involvement in professional societies was emailed to 616 directors of Joint Review Committee on Education in Radiologic Technology (JRCERT)-accredited radiography programs. A total of 219 responses were received, for a 36% response rate. Of these, 89 respondents (41%) answered that their programs require students to join a professional organization. The society respondents most often required (70%) was a state radiography society. Sixty respondents (68%) answered that students join a society at the beginning of the radiography program (from matriculation to 3 months in). Of programs requiring student membership in professional societies, 42 (49%) reported that their students attend the state or national society annual conference; however, participation in activities at the conferences and in the society throughout the year is lower than conference attendance. Some directors stated that although their programs' policies do not allow membership mandates, they encourage students to become members, primarily so that they can access webinars and other educational materials or information related to the profession. Survey data showed that most JRCERT-accredited radiography programs support but do not require student membership in professional organizations. The data reveal that more programs have added those requirements in recent years. Increased student participation could be realized if programs mandated membership and supported it financially. ©2017 American Society of Radiologic Technologists.

The viability of ADVANTG deterministic method for synthetic radiography generation

NASA Astrophysics Data System (ADS)

Bingham, Andrew; Lee, Hyoung K.

2018-07-01

Fast simulation techniques to generate synthetic radiographic images of high resolution are helpful when new radiation imaging systems are designed. However, the standard stochastic approach requires lengthy run time with poorer statistics at higher resolution. The investigation of the viability of a deterministic approach to synthetic radiography image generation was explored. The aim was to analyze a computational time decrease over the stochastic method. ADVANTG was compared to MCNP in multiple scenarios including a small radiography system prototype, to simulate high resolution radiography images. By using ADVANTG deterministic code to simulate radiography images the computational time was found to decrease 10 to 13 times compared to the MCNP stochastic approach while retaining image quality.

Radiography Capabilities for Matter-Radiation Interactions in Extremes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walstrom, Peter Lowell; Garnett, Robert William; Chapman, Catherine A. B

The Matter-Radiation Interactions in Extremes (MaRIE) experimental facility will be used to discover and design the advanced materials needed to meet 21st century national security and energy security challenges. This new facility will provide the new tools scientists need to develop next-generation materials that will perform predictably and on-demand for currently unattainable lifetimes in extreme environments. The MaRIE facility is based on upgrades to the existing LANSCE 800-MeV proton linac and a new 12-GeV electron linac and associated X-ray FEL to provide simultaneous multiple probe beams, and new experimental areas. In addition to the high-energy photon probe beam, both electronmore » and proton radiography capabilities will be available at the MaRIE facility. Recently, detailed radiography system studies have been performed to develop conceptual layouts of high-magnification electron and proton radiography systems that can meet the experimental requirements for the expected first experiments to be performed at the facility. A description of the radiography systems, their performance requirements, and a proposed facility layout are presented.« less

Feline dental radiography and radiology: A primer.

PubMed

Niemiec, Brook A

2014-11-01

Information crucial to the diagnosis and treatment of feline oral diseases can be ascertained using dental radiography and the inclusion of this technology has been shown to be the best way to improve a dental practice. Becoming familar with the techniques required for dental radiology and radiography can, therefore, be greatly beneficial. Novices to dental radiography may need some time to adjust and become comfortable with the techniques. If using dental radiographic film, the generally recommended 'E' or 'F' speeds may be frustrating at first, due to their more specific exposure and image development requirements. Although interpreting dental radiographs is similar to interpreting a standard bony radiograph, there are pathologic states that are unique to the oral cavity and several normal anatomic structures that may mimic pathologic changes. Determining which teeth have been imaged also requires a firm knowledge of oral anatomy as well as the architecture of dental films/digital systems. This article draws on a range of dental radiography and radiology resources, and the benefit of the author's own experience, to review the basics of taking and interpreting intraoral dental radiographs. A simplified method for positioning the tubehead is explained and classic examples of some common oral pathologies are provided. © ISFM and AAFP 2014.

Characterization of HANARO neutron radiography facility in accordance with ASTM standard E545-91/E803-91 for KOLAS/ISO17025.

PubMed

Cheul-Muu, Sim; Ki-Yong, Nam; In-Cheol, Lim; Chang-Hee, Lee; Ha-Lim, Choi

2004-10-01

As neutron radiography is even more in demand for industrial applications of aircraft, turbine blade, automobile, explosive igniters, etc, it is necessary to review the standards which are the most appropriate for preparing the procedures for setting up the QA system. Recently, Korea Of Lab Accreditation Scheme (KOLAS) was originated from ISO 17025. It is widely recognized by research peer groups for conducting valid tests. The neutron radiography facility (NRF) of High Flux Advanced Neutron Application Reactor (HANARO), which started ion 1996, is the preliminary stages of KOLAS. The HANARO NRF is not only characterized using ASTM standards E545-91/E803-91 to satisfy the requirements of KOLAS, but in the design phase of the tomography system.

Tests of cosmic ray radiography for power industry applications

NASA Astrophysics Data System (ADS)

Durham, J. M.; Guardincerri, E.; Morris, C. L.; Bacon, J.; Fabritius, J.; Fellows, S.; Poulson, D.; Plaud-Ramos, K.; Renshaw, J.

2015-06-01

In this report, we assess muon multiple scattering tomography as a non-destructive inspection technique in several typical areas of interest to the nuclear power industry, including monitoring concrete degradation, gate valve conditions, and pipe wall thickness. This work is motivated by the need for imaging methods that do not require the licensing, training, and safety controls of x-rays, and by the need to be able to penetrate considerable overburden to examine internal details of components that are otherwise inaccessible, with minimum impact on industrial operations. In some scenarios, we find that muon tomography may be an attractive alternative to more typical measurements.

Tests of cosmic ray radiography for power industry applications

DOE PAGES

Durham, J. M.; Guardincerri, E.; Morris, C. L.; ...

2015-06-30

In this report, we assess muon multiple scattering tomography as a non-destructive inspection technique in several typical areas of interest to the nuclear power industry, including monitoring concrete degradation, gate valve conditions, and pipe wall thickness. This work is motivated by the need for imaging methods that do not require the licensing, training, and safety controls of x-rays, and by the need to be able to penetrate considerable overburden to examine internal details of components that are otherwise inaccessible, with minimum impact on industrial operations. In some instances, we find that muon tomography may be an attractive alternative to moremore » typical measurements.« less

Satisfaction of Search in Chest Radiography 2015.

PubMed

Berbaum, Kevin S; Krupinski, Elizabeth A; Schartz, Kevin M; Caldwell, Robert T; Madsen, Mark T; Hur, Seung; Laroia, Archana T; Thompson, Brad H; Mullan, Brian F; Franken, Edmund A

2015-11-01

Two decades have passed since the publication of laboratory studies of satisfaction of search (SOS) in chest radiography. Those studies were performed using film. The current investigation tests for SOS effects in computed radiography of the chest. Sixty-four chest computed radiographs half demonstrating various "test" abnormalities were read twice by 20 radiologists, once with and once without the addition of a simulated pulmonary nodule. Receiver-operating characteristic detection accuracy and decision thresholds were analyzed to study the effects of adding the nodule on detecting the test abnormalities. Results of previous studies were reanalyzed using similar modern techniques. In the present study, adding nodules did not influence detection accuracy for the other abnormalities (P = .93), but did induce a reluctance to report them (P < .001). Adding nodules did not affect inspection time (P = .58) so the reluctance to report was not associated with reduced search. Reanalysis revealed a similar decision threshold shift that had not been recognized in the early studies of SOS in chest radiography (P < .01) in addition to reduced detection accuracy (P < .01). The nature of SOS in chest radiography has changed, but it is not clear why. SOS may be changing as a function of changes in radiology education and practice. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.

Comprehensive optimization process of paranasal sinus radiography.

PubMed

Saarakkala, S; Nironen, K; Hermunen, H; Aarnio, J; Heikkinen, J O

2009-04-01

The optimization of radiological examinations is important in order to reduce unnecessary patient radiation exposure. To perform a comprehensive optimization process for paranasal sinus radiography at Mikkeli Central Hospital, Finland. Patients with suspicion of acute sinusitis were imaged with a Kodak computed radiography (CR) system (n=20) and with a Philips digital radiography (DR) system (n=30) using focus-detector distances (FDDs) of 110 cm, 150 cm, or 200 cm. Patients' radiation exposure was determined in terms of entrance surface dose and dose-area product. Furthermore, an anatomical phantom was used for the estimation of point doses inside the head. Clinical image quality was evaluated by an experienced radiologist, and physical image quality was evaluated from the digital radiography phantom. Patient doses were significantly lower and image quality better with the DR system compared to the CR system. The differences in patient dose and physical image quality were small with varying FDD. Clinical image quality of the DR system was lowest with FDD of 200 cm. Further, imaging with FDD of 150 cm was technically easier for the technologist to perform than with FDD of 110 cm. After optimization, it was recommended that the DR system with FDD of 150 cm should always be used at Mikkeli Central Hospital. We recommend this kind of comprehensive approach in all optimization processes of radiological examinations.

A comparison between conventional and digital radiography in root canal working length determination.

PubMed

Farida, Abesi; Maryam, Ehsani; Ali, Mirzapour; Ehsan, Moudi; Sajad, Yousefi; Soraya, Khafri

2013-01-01

Obtaining a correct working length is necessary for successful root canal treatment. The aim of this study was to compare conventional and digital radiography in measuring root canal working length. In this in vitro study 20 mesio buccal canal from maxillary first molars with moderate and severe curvature and 20 canal form anterior teeth with mild curvature were chosen and their working length were measured with number 15 k file (Maillefer, DENTSPLY, Germany). Then for each canal five radiographies were taken, three conventional radiographies using three methods of processing: Manual, automatic, and monobath solution; in addition to two other digital radiographies using CCD and PSP receptors. Two independent observers measured working length in each technique. Finally, the mean of working length in each group was compared with real working length using a paired T-test. Also a one-way ANOVA test was used for comparing the two groups. The level of statistical significance was P < 0.05. The results have shown that there was a high interobserver agreement on the measurements of the working length in conventional and digital radiography (P ≤ 0.001). Also there was no significant difference between conventional and digital radiography in measuring working length (P > 0.05). Therefore it was concluded that the accuracy of digital radiography is comparable with conventional radiography in measuring working length, so considering the advantages of the digital radiography, it can be used for working length determination.

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

PubMed

Peters, Sinead E; Brennan, Patrick C

2002-09-01

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

X-radiography of trace fossils in limestones and dolostones from the Jurassic Smackover Formation, south Alabama

DOE Office of Scientific and Technical Information (OSTI.GOV)

Esposito, R.A.; Castleman, S.P.; King, D.T. Jr.

X-radiography has been useful in studying biogenic sedimentary structures in unconsolidated sediments but the technique has not been applied often to the study of hard carbonate rock. The authors have applied x-radiography to the study of the lower part of the Smackover to enhance the complete petrologic description of the rock. The lower Smackover has many dense micrite intervals and intervals of monotonous, thin graded beds. Parts of the lower Smackover is also dolomitized. None of the above rocks contains significant amount of skeletal debris and trace fossils are not generally obvious in an etched slab of core. In limestone,more » they have detected well-preserved trace fossils by x-radiography, however. The dolostones show no traces using our method. In limestones, the traces are marked by minute amounts of finely divided iron sulfides. This causes a slight density difference resulting in greater x-ray absorption. They recognize two main trace-fossil types: a Thalassinoides best seen in slabs cut parallel to bedding and a Zoophycos best seen in slabs cut perpendicular to bedding. The technique requires a slab cut 8 mm thick with parallel flat surfaces and a medical x-ray unit using accelerating voltages of 66 kV and 10 mas. Traces are most successfully imaged on industrial-quality films.« less

Computed radiography imaging plates and associated methods of manufacture

DOEpatents

Henry, Nathaniel F.; Moses, Alex K.

2015-08-18

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

Industrial radiography with cosmic-ray muons: A progress report

NASA Astrophysics Data System (ADS)

Gilboy, W. B.; Jenneson, P. M.; Simons, S. J. R.; Stanley, S. J.; Rhodes, D.

2007-09-01

Cosmic-ray produced muons arrive at the surface of the earth with enormous energies ranging up to 1012 GeV. There have been sporadic attempts to exploit their extreme penetration through matter to probe the internal structures of very large objects, including an Egyptian pyramid and a volcano but their very low intensity per unit area ( ≈1 cm-2 per min) generally restricts the practicably attainable spatial resolution to large dimensions. Nevertheless the more intense low energy region of the muon spectrum has recently been shown to be capable of detecting high-Z objects with dimensions of the order of 10 cm hidden inside large transport containers in measurement times of minutes. These various developments have encouraged further studies of potential industrial uses of cosmic-ray muons in industrial applications. In order to gain maximum benefit from the low muon flux large area detectors are required and plastic scintillators offer useful advantages in size, cost and simplicity. Scintillator slabs up to 1 m2 square and 76.2 mm thick are undergoing testing for applications in the nuclear industry. The most direct approach employs photomultiplier tubes at each corner to measure the relative sizes of muon induced pulses to determine the location of each muon track passing through the scintillator. The performance of this technique is reported and its imaging potential is assessed.

A benchmark for comparison of dental radiography analysis algorithms.

PubMed

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

2016-07-01

Dental radiography plays an important role in clinical diagnosis, treatment and surgery. In recent years, efforts have been made on developing computerized dental X-ray image analysis systems for clinical usages. A novel framework for objective evaluation of automatic dental radiography analysis algorithms has been established under the auspices of the IEEE International Symposium on Biomedical Imaging 2015 Bitewing Radiography Caries Detection Challenge and Cephalometric X-ray Image Analysis Challenge. In this article, we present the datasets, methods and results of the challenge and lay down the principles for future uses of this benchmark. The main contributions of the challenge include the creation of the dental anatomy data repository of bitewing radiographs, the creation of the anatomical abnormality classification data repository of cephalometric radiographs, and the definition of objective quantitative evaluation for comparison and ranking of the algorithms. With this benchmark, seven automatic methods for analysing cephalometric X-ray image and two automatic methods for detecting bitewing radiography caries have been compared, and detailed quantitative evaluation results are presented in this paper. Based on the quantitative evaluation results, we believe automatic dental radiography analysis is still a challenging and unsolved problem. The datasets and the evaluation software will be made available to the research community, further encouraging future developments in this field. (http://www-o.ntust.edu.tw/~cweiwang/ISBI2015/). Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

The quality assessment of radial and tangential neutron radiography beamlines of TRR

NASA Astrophysics Data System (ADS)

Choopan Dastjerdi, M. H.; Movafeghi, A.; Khalafi, H.; Kasesaz, Y.

2017-07-01

To achieve a quality neutron radiographic image in a relatively short exposure time, the neutron radiography beam must be of good quality and relatively high neutron flux. Characterization of a neutron radiography beam, such as determination of the image quality and the neutron flux, is vital for producing quality radiographic images and also provides a means to compare the quality of different neutron radiography facilities. This paper provides a characterization of the radial and tangential neutron radiography beamlines at the Tehran research reactor. This work includes determination of the facilities category according to the American Society for Testing and Materials (ASTM) standards, and also uses the gold foils to determine the neutron beam flux. The radial neutron beam is a Category I neutron radiography facility, the highest possible quality level according to the ASTM. The tangential beam is a Category IV neutron radiography facility. Gold foil activation experiments show that the measured neutron flux for radial beamline with length-to-diameter ratio (L/D) =150 is 6.1× 106 n cm-2 s-1 and for tangential beamline with (L/D)=115 is 2.4× 104 n cm-2 s-1.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Theocharopoulos, Nicholas; Chatzakis, Georgios; Damilakis, John

2009-10-15

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

Utilization and costs of lumbar and full spine radiography by Ontario chiropractors from 1994 to 2001.

PubMed

Ammendolia, Carlo; Côté, Pierre; Hogg-Johnson, Sheilah; Bombardier, Claire

2009-07-01

In Ontario, chiropractors see one-third of patients who seek care for low back pain. Previous studies suggest that chiropractors have high utilization rates of lumbar and full spine radiography. There has been a proliferation of evidence-based guidelines recommending that plain film radiography be used only to assess high-risk patients with low back pain. Evidence for the use of full spine radiography, except for the evaluation of scoliosis is lacking. It is uncertain what impact the growing evidence against their use has had on radiography utilization by Ontario chiropractors. To describe the annual costs and use of lumbar and full spine plain film radiography among Ontario chiropractors between 1994 and 2001. Time-trend analysis of radiography utilization by Ontario chiropractors. Chiropractic claims data submitted to the Ontario Health Insurance Plan or the Workplace Safety & Insurance Board from 1994/1995 to 2000/2001. Change in the annual cost and proportion of claimants receiving lumbar and full spine radiography. Time-trend analysis of chiropractic claims submitted to the Ontario Health Insurance Plan (OHIP) or Workplace Safety & Insurance Board (WSIB) from 1994/1995 to 2000/2001 fiscal years. During the 7-year period, the proportion of OHIP claimants receiving lumbar spine radiography decreased from 4.54% to 3.25% and for full spine radiography from 3.87% to 3.04%. For WSIB claimants, lumbar spine radiography deceased from 6.49% to 3.30% of claimants and full spine radiography from 1.51% to 0.94%. OHIP payments for lumbar spine radiography decreased 12.7% to $562,944, whereas full spine radiography payments decreased 5.3% to $1,071,408. WSIB lumbar and full spine radiography payments decreased 44.2% and 34.3% to $31,202 and $11,713 respectively. Claims data from the two largest third-party payers of chiropractic services in Ontario, suggest that lumbar and full spine radiography, and their associated costs decreased steadily between 1994 and 2001.

Quantitative studies on inner interfaces in conical metal joints using hard x-ray inline phase contrast radiography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zabler, S.; Rack, T.; Nelson, K.

2010-10-15

Quantitative investigation of micrometer and submicrometer gaps between joining metal surfaces is applied to conical plug-socket connections in dental titanium implants. Microgaps of widths well beyond the resolving power of industrial x-ray systems are imaged by synchrotron phase contrast radiography. Furthermore, by using an analytical model for the relatively simple sample geometry and applying it to numerical forward simulations of the optical Fresnel propagation, we show that quantitative measurements of the microgap width down to 0.1 {mu}m are possible. Image data recorded at the BAMline (BESSY-II light source, Germany) are presented, with the resolving power of the imaging system beingmore » 4 {mu}m in absorption mode and {approx}14 {mu}m in phase contrast mode (z{sub 2}=0.74 m). Thus, phase contrast radiography, combined with numerical forward simulations, is capable of measuring the widths of gaps that are two orders of magnitude thinner than the conventional detection limit.« less

Digital Radiography

NASA Technical Reports Server (NTRS)

1986-01-01

System One, a digital radiography system, incorporates a reusable image medium (RIM) which retains an image. No film is needed; the RIM is read with a laser scanner, and the information is used to produce a digital image on an image processor. The image is stored on an optical disc. System allows the radiologist to "dial away" unwanted images to compare views on three screens. It is compatible with existing equipment and cost efficient. It was commercialized by a Stanford researcher from energy selective technology developed under a NASA grant.

Dose audit for patients undergoing two common radiography examinations with digital radiology systems.

PubMed

İnal, Tolga; Ataç, Gökçe

2014-01-01

We aimed to determine the radiation doses delivered to patients undergoing general examinations using computed or digital radiography systems in Turkey. Radiographs of 20 patients undergoing posteroanterior chest X-ray and of 20 patients undergoing anteroposterior kidney-ureter-bladder radiography were evaluated in five X-ray rooms at four local hospitals in the Ankara region. Currently, almost all radiology departments in Turkey have switched from conventional radiography systems to computed radiography or digital radiography systems. Patient dose was measured for both systems. The results were compared with published diagnostic reference levels (DRLs) from the European Union and International Atomic Energy Agency. The average entrance surface doses (ESDs) for chest examinations exceeded established international DRLs at two of the X-ray rooms in a hospital with computed radiography. All of the other ESD measurements were approximately equal to or below the DRLs for both examinations in all of the remaining hospitals. Improper adjustment of the exposure parameters, uncalibrated automatic exposure control systems, and failure of the technologists to choose exposure parameters properly were problems we noticed during the study. This study is an initial attempt at establishing local DRL values for digital radiography systems, and will provide a benchmark so that the authorities can establish reference dose levels for diagnostic radiology in Turkey.

Optimisation and establishment of diagnostic reference levels in paediatric plain radiography

NASA Astrophysics Data System (ADS)

Paulo, Graciano do Nascimento Nobre

Purpose: This study aimed to propose Diagnostic Reference Levels (DRLs) in paediatric plain radiography and to optimise the most frequent paediatric plain radiography examinations in Portugal following an analysis and evaluation of current practice. Methods and materials: Anthropometric data (weight, patient height and thickness of the irradiated anatomy) was collected from 9,935 patients referred for a radiography procedure to one of the three dedicated paediatric hospitals in Portugal. National DRLs were calculated for the three most frequent X-ray procedures at the three hospitals: chest AP/PA projection; abdomen AP projection; pelvis AP projection. Exposure factors and patient dose were collected prospectively at the clinical sites. In order to analyse the relationship between exposure factors, the use of technical features and dose, experimental tests were made using two anthropomorphic phantoms: a) CIRSTM ATOM model 705; height: 110cm, weight: 19kg and b) Kyoto kagakuTM model PBU-60; height: 165cm, weight: 50kg. After phantom data collection, an objective image analysis was performed by analysing the variation of the mean value of the standard deviation, measured with OsiriX software (Pixmeo, Switzerland). After proposing new exposure criteria, a Visual Grading Characteristic image quality evaluation was performed blindly by four paediatric radiologists, each with a minimum of 10 years of professional experience, using anatomical criteria scoring. Results: DRLs by patient weight groups have been established for the first time. ESAKP75 DRLs for both patient age and weight groups were also obtained and are described in the thesis. Significant dose reduction was achieved through the implementation of an optimisation programme: an average reduction of 41% and 18% on KAPP75 and ESAKP75, respectively for chest plain radiography; an average reduction of 58% and 53% on KAPP75 and ESAKP75, respectively for abdomen plain radiography; and an average reduction of 47% and

Dynamic chest radiography: flat-panel detector (FPD) based functional X-ray imaging.

PubMed

Tanaka, Rie

2016-07-01

Dynamic chest radiography is a flat-panel detector (FPD)-based functional X-ray imaging, which is performed as an additional examination in chest radiography. The large field of view (FOV) of FPDs permits real-time observation of the entire lungs and simultaneous right-and-left evaluation of diaphragm kinetics. Most importantly, dynamic chest radiography provides pulmonary ventilation and circulation findings as slight changes in pixel value even without the use of contrast media; the interpretation is challenging and crucial for a better understanding of pulmonary function. The basic concept was proposed in the 1980s; however, it was not realized until the 2010s because of technical limitations. Dynamic FPDs and advanced digital image processing played a key role for clinical application of dynamic chest radiography. Pulmonary ventilation and circulation can be quantified and visualized for the diagnosis of pulmonary diseases. Dynamic chest radiography can be deployed as a simple and rapid means of functional imaging in both routine and emergency medicine. Here, we focus on the evaluation of pulmonary ventilation and circulation. This review article describes the basic mechanism of imaging findings according to pulmonary/circulation physiology, followed by imaging procedures, analysis method, and diagnostic performance of dynamic chest radiography.

Quality aspects of digital radiography in general dental practice.

PubMed

Hellén-Halme, Kristina

2007-01-01

The number of dentists who have converted from conventional film radiography to digital radiography continues to grow. A digital system has numerous advantages, but there are also many new aspects to consider. The overall aim of this thesis was to study how digital radiography was used in general dental practices. The specific aims were to study how different factors affected image quality. To determine whether there were any differences in image quality between conventional film radiographs and digital radiographs, 4863 images (540 cases) were evaluated. The cases had been sent to the Swedish Dental Insurance Office for prior treatment approval. The image quality of digital radiographs was found to be significantly lower than that of film radiographs. This result led to a questionnaire study of dentists experienced in digital radiography. In 2003, a questionnaire was sent to the 139 general practice dentists who worked with digital radiography in Skine, Sweden; the response rate was 94%. Many general practice dentists had experienced several problems (65%), and less than half of the digital systems (40%) underwent some kind of quality control. One of the weaker links in the technical chain of digital radiography appeared to be the monitor. A field study to 19 dentists at their clinics found that the brightness and contrast settings of the monitors had to be adjusted to obtain the subjectively best image quality. The ambient light in the evaluation room was also found to affect the diagnostic outcome of low-contrast patterns in radiographs. To evaluate the effects of ambient light and technical adjustments of the monitor, a study using standardised set-ups was designed. Seven observers evaluated radiographs of 100 extracted human teeth for approximal caries under five different combinations of brightness and contrast settings on two different occasions with high and low ambient light levels in the evaluation room. The ability to diagnose carious lesions was found

Magnifying lens for 800 MeV proton radiography.

PubMed

Merrill, F E; Campos, E; Espinoza, C; Hogan, G; Hollander, B; Lopez, J; Mariam, F G; Morley, D; Morris, C L; Murray, M; Saunders, A; Schwartz, C; Thompson, T N

2011-10-01

This article describes the design and performance of a magnifying magnetic-lens system designed, built, and commissioned at the Los Alamos National Laboratory (LANL) for 800 MeV flash proton radiography. The technique of flash proton radiography has been developed at LANL to study material properties under dynamic loading conditions through the analysis of time sequences of proton radiographs. The requirements of this growing experimental program have resulted in the need for improvements in spatial radiographic resolution. To meet these needs, a new magnetic lens system, consisting of four permanent magnet quadrupoles, has been developed. This new lens system was designed to reduce the second order chromatic aberrations, the dominant source of image blur in 800 MeV proton radiography, as well as magnifying the image to reduce the blur contribution from the detector and camera systems. The recently commissioned lens system performed as designed, providing nearly a factor of three improvement in radiographic resolution.

Magnifying lens for 800 MeV proton radiography

NASA Astrophysics Data System (ADS)

Merrill, F. E.; Campos, E.; Espinoza, C.; Hogan, G.; Hollander, B.; Lopez, J.; Mariam, F. G.; Morley, D.; Morris, C. L.; Murray, M.; Saunders, A.; Schwartz, C.; Thompson, T. N.

2011-10-01

This article describes the design and performance of a magnifying magnetic-lens system designed, built, and commissioned at the Los Alamos National Laboratory (LANL) for 800 MeV flash proton radiography. The technique of flash proton radiography has been developed at LANL to study material properties under dynamic loading conditions through the analysis of time sequences of proton radiographs. The requirements of this growing experimental program have resulted in the need for improvements in spatial radiographic resolution. To meet these needs, a new magnetic lens system, consisting of four permanent magnet quadrupoles, has been developed. This new lens system was designed to reduce the second order chromatic aberrations, the dominant source of image blur in 800 MeV proton radiography, as well as magnifying the image to reduce the blur contribution from the detector and camera systems. The recently commissioned lens system performed as designed, providing nearly a factor of three improvement in radiographic resolution.

Dose audit for patients undergoing two common radiography examinations with digital radiology systems

PubMed Central

İnal, Tolga; Ataç, Gökçe

2014-01-01

PURPOSE We aimed to determine the radiation doses delivered to patients undergoing general examinations using computed or digital radiography systems in Turkey. MATERIALS AND METHODS Radiographs of 20 patients undergoing posteroanterior chest X-ray and of 20 patients undergoing anteroposterior kidney-ureter-bladder radiography were evaluated in five X-ray rooms at four local hospitals in the Ankara region. Currently, almost all radiology departments in Turkey have switched from conventional radiography systems to computed radiography or digital radiography systems. Patient dose was measured for both systems. The results were compared with published diagnostic reference levels (DRLs) from the European Union and International Atomic Energy Agency. RESULTS The average entrance surface doses (ESDs) for chest examinations exceeded established international DRLs at two of the X-ray rooms in a hospital with computed radiography. All of the other ESD measurements were approximately equal to or below the DRLs for both examinations in all of the remaining hospitals. Improper adjustment of the exposure parameters, uncalibrated automatic exposure control systems, and failure of the technologists to choose exposure parameters properly were problems we noticed during the study. CONCLUSION This study is an initial attempt at establishing local DRL values for digital radiography systems, and will provide a benchmark so that the authorities can establish reference dose levels for diagnostic radiology in Turkey. PMID:24317331

Radiography student perceptions of clinical stressors.

PubMed

Mason, Starla L

2006-01-01

Technological change and the increasingly rapid pace of life in the United States and globally have contributed to increased levels of stress and burnout experienced by workers and their families. Although studies are available on the levels of workplace stress and burnout affecting radiographers, little to no research has been conducted to assess the stressors encountered by radiography students in the clinical environment. This study was designed to pinpoint the primary sources of stress for radiography students and to determine the most effective measures to alleviate the stress that students experience in the clinical environment. It also sought to identify the clinical activities and practices that enhance learning. A convenience sample of radiography students attending an Association of Collegiate Educators in Radiologic Technology meeting was surveyed. Students were asked to rank their greatest stressors in the clinical environment, the most desired qualities in a clinical instructor and clinical environment, and the clinical practices and activities that best enhance their learning. Descriptive statistics were used to report the results. Data were collected for 82 first-year and second-year students. Students identified 7 primary clinical stressors: fear of making a mistake/repeat, feeling unprepared/inexperienced, intimidation by staff and by instructors, difficult/critical patients, hurtful criticism, too much supervision and negative responses to questions/requests for help. Students indicated that more frequent feedback, availability of the clinical instructor and other staff, assurance that mistakes happen and the opportunity to make mistakes were clinical practices that eased stress. The majority of students cited hands-on learning and repetition as the clinical activities that most reinforced their learning. Summary Radiography students in this survey experience some of the same clinical stressors as radiographers and other allied health workers

Outcome of recommendations for radiographic follow-up of pneumonia on outpatient chest radiography.

PubMed

Little, Brent P; Gilman, Matthew D; Humphrey, Kathryn L; Alkasab, Tarik K; Gibbons, Fiona K; Shepard, Jo-Anne O; Wu, Carol C

2014-01-01

Follow-up chest radiographs are frequently recommended by radiologists to document the clearing of radiographically suspected pneumonia. However, the clinical utility of follow-up radiography is not well understood. The purpose of this study was to examine the incidence of important pulmonary pathology revealed during follow-up imaging of suspected pneumonia on outpatient chest radiography. Reports of 29,138 outpatient chest radiography examinations performed at an academic medical center in 2008 were searched to identify cases in which the radiologist recommended follow-up chest radiography for presumed community-acquired pneumonia (n = 618). Descriptions of index radiographic abnormalities were recorded. Reports of follow-up imaging (radiography and CT) performed during the period from January 2008 to January 2010 were reviewed to assess the outcome of the index abnormality. Clinical history, demographics, microbiology, and pathology reports were reviewed and recorded. Compliance with follow-up imaging recommendations was 76.7%. In nine of 618 cases (1.5%), a newly diagnosed malignancy corresponded to the abnormality on chest radiography initially suspected to be pneumonia. In 23 of 618 cases (3.7%), an alternative nonmalignant disease corresponded with the abnormality on chest radiography initially suspected to be pneumonia. Therefore, in 32 of 618 patients (5.2%), significant new pulmonary diagnoses were established during follow-up imaging of suspected pneumonia. Follow-up imaging of radiographically suspected pneumonia leads to a small number of new diagnoses of malignancy and important nonmalignant diseases, which may alter patient management.

System for uncollimated digital radiography

DOEpatents

Wang, Han; Hall, James M.; McCarrick, James F.; Tang, Vincent

2015-08-11

The inversion algorithm based on the maximum entropy method (MEM) removes unwanted effects in high energy imaging resulting from an uncollimated source interacting with a finitely thick scintillator. The algorithm takes as input the image from the thick scintillator (TS) and the radiography setup geometry. The algorithm then outputs a restored image which appears as if taken with an infinitesimally thin scintillator (ITS). Inversion is accomplished by numerically generating a probabilistic model relating the ITS image to the TS image and then inverting this model on the TS image through MEM. This reconstruction technique can reduce the exposure time or the required source intensity without undesirable object blurring on the image by allowing the use of both thicker scintillators with higher efficiencies and closer source-to-detector distances to maximize incident radiation flux. The technique is applicable in radiographic applications including fast neutron, high-energy gamma and x-ray radiography using thick scintillators.

Megavoltage cargo radiography with dual energy material decomposition

NASA Astrophysics Data System (ADS)

Shikhaliev, Polad M.

2018-02-01

Megavoltage (MV) radiography has important applications in imaging large cargos for detecting illicit materials. A useful feature of MV radiography is the possibility of decomposing and quantifying materials with different atomic numbers. This can be achieved by imaging cargo at two different X-ray energies, or dual energy (DE) radiography. The performance of both single energy and DE radiography depends on beam energy, beam filtration, radiation dose, object size, and object content. The purpose of this work was to perform comprehensive qualitative and quantitative investigations of the image quality in MV radiography depending on the above parameters. A digital phantom was designed including Fe background with thicknesses of 2cm, 6cm, and 18cm, and materials samples of Polyethylene, Fe, Pb, and U. The single energy images were generated at x-ray beam energies 3.5MV, 6MV, and 9MV. The DE material decomposed images were generated using interlaced low and high energy beams 3.5/6MV and 6/9MV. The X-ray beams were filtered by low-Z (Polyethylene) and high-Z (Pb) filters with variable thicknesses. The radiation output of the accelerator was kept constant for all beam energies. The image quality metrics was signal-to-noise ratio (SNR) of the particular sample over a particular background. It was found that the SNR depends on the above parameters in a complex way, but can be optimized by selecting a particular set of parameters. For some imaging setups increased filter thicknesses, while strongly absorbing the beams, increased the SNR of material decomposed images. Beam hardening due to polyenergetic x-ray spectra resulted in material decomposition errors, but this could be addressed using region of interest decomposition. It was shown that it is not feasible to separate the materials with close atomic numbers using the DE method. Particularly, Pb and U were difficult to decompose, at least at the dose levels allowed by radiation source and safety requirements.

Dichotomy between theory and practice in chest radiography and its impact on students.

PubMed

Botwe, Benard O; Arthur, Lawrence; Tenkorang, Michael K K; Anim-Sampong, Samuel

2017-06-01

It is important that theory is synchronous with clinical practices that students engage in. Lack of congruence between theory and practice presents serious problems to students. This study was therefore conducted to determine if there was a theory-practice gap in chest radiography during clinical rotations, and any associated causes and effects on radiography students. A descriptive survey design was used to conduct this study from 2 February to 27 July 2014. A semi-structured questionnaire consisting of open- and close-ended questions was used to purposively collect data from 26 radiography students in Ghana who had completed theory lessons in chest radiography and had either completed or were undertaking clinical rotations in chest radiography. Twenty-five (96%) respondents indicated the presence of theory-practice gap in chest radiography during clinical rotations, where differences between theory and clinical practice were observed. Lack of working materials 16 (62%), heavy workload 14 (54%), equipment breakdowns 14 (54%) and supervisory factors 11 (43%) were identified as the causes. Many students (81%) experienced diverse adverse effects such as confusion 10 (38%), poor performance during clinical examinations 6 (23%) and entire loss of interest in the professional training 1 (4%) of this dichotomy. Dichotomy between theory and practice found in chest radiography has diverse adverse effects on students. Regular feedback on the quality of clinical practice received by students should be encouraged to determine the existence of any gaps between theory and practice in order to promote effective clinical rotation programmes in radiography. © 2016 The Authors. Journal of Medical Radiation Sciences published by John Wiley & Sons Australia, Ltd on behalf of Australian Society of Medical Imaging and Radiation Therapy and New Zealand Institute of Medical Radiation Technology.

A survey of digital radiography practice in four South African teaching hospitals: an illuminative study.

PubMed

Nyathi, T; Chirwa, Tf; van der Merwe, Dg

2010-01-01

The purpose of this study was to assess radiographer familiarity and preferences with digital radiography in four teaching hospitals and thereafter make recommendations in line with the migration from screen film to digital radiography. A questionnaire was designed to collect data from either qualified or student radiographers from four teaching hospitals. From the four teaching hospitals, there were a total of 205 potential respondents. Among other things, responses regarding experiences and preferences with digital radiography, quality control procedures, patient dose, advantages and disadvantages of digital radiography were sought. The information collected was based on self-reporting by the participants. The study is exploratory in nature and descriptive statistics were generated from the collected data using Microsoft Excel 2007 and StatsDirect software. Sixty-three out of 205 (31%) radiographers from all the four radiology centers responded to the circulated questionnaire. Only 15% (8) of the qualified radiographers had 4 or more years of experience with digital radiography compared to 68% (36) for the same amount of experience with screen-film radiography. Sixty-one percent (38) of the participants had been exposed to digital radiography during their lectures while at university. A small proportion, 16% (10) of the respondents underwent formal training in quality control procedures on the digital X-ray units they were using. Slightly more than half (55%) of the participants felt it was easier for them to retake an image in digital radiography than in screen film radiography. The results of this survey showed that the participants are familiar with digital radiography and have embraced this relatively new technology as shown by the fact that they can identify both its advantages and disadvantages as applied to clinical practice. However, there are minimal quality control procedures specific to digital radiography being undertaken as such there is need for

Scatter in Cargo Radiography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Erin A. Miller; Joseph A. Caggiano; Robert C. Runkle

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

Proton radiography based on near-threshold Cerenkov radiation

DOEpatents

van Bibber, Karl A.; Dietrich, Frank S.

2003-01-01

A Cerenkov imaging system for charged particle radiography that determines the energy loss of the charged particle beam passing through an object. This energy loss information provides additional detail on target densities when used with traditional radiographic techniques like photon or x-ray radiography. In this invention a probe beam of 800 MeV to 50 GeV/c charged particles is passed through an object to be imaged, an imaging magnetic spectrometer, to a silicon aerogel Cerenkov radiator where the charged particles emitted Cerenkov light proportional to their velocity. At the same beam focal plane, a particle scintillator produces a light output proportional to the incident beam flux. Optical imaging systems relay the Cerenkov and scintillator information to CCD's or other measurement equipment. A ratio between the Cerenkov and scintillator is formed, which is directly proportional to the line density of the object for each pixel measured. By rotating the object, tomographic radiography may be performed. By applying pulses of beam, discrete time-step movies of dynamic objects may be made.

General Dental Practitioners’ Concept towards Using Radiography and Apex-Locators in Endodontics

PubMed Central

Raoof, Maryam; Heidaripour, Maryam; Shahravan, Arash; Haghani, Jahangir; Afkham, Arash; Razifar, Mahsa; Mohammadizadeh, Sakineh

2014-01-01

Introduction: Despite being the gold standard as well as a routine technique in endodontics, radiographic working length (WL) determination owns many drawbacks. Electronic apex-locators (EALs) are recommended to complement radiographies. The aim of this study was to evaluate the perceptions of Iranian general dental practitioners (GDPs) towards using radiography and EAL. Methods and Materials: Three hundred and ninety one GDPs attending the 53th Iranian Dental Association Congress completed a questionnaire focusing on the use of radiography and EALs during the various stages of root canal treatment. The data was analyzed with the chi-square test with the level of significance set at 0.05. The results were then calculated as frequencies and percentages. Results: More than half of the GDPs reported using radiographs as the sole method for WL determination. A total of 30.4% of the practitioners were using the combined approach during root canal therapy of a single-rooted tooth, while 38.9% used this method in multi-rooted teeth. Approximately half of the respondents would not order follow-up radiographies after root canal treatment. Conclusion: Radiography continues to be the most common method for WL determination in Iran. PMID:25386209

Final-year diagnostic radiography students' perception of role models within the profession.

PubMed

Conway, Alinya; Lewis, Sarah; Robinson, John

2008-01-01

Within a clinical education setting, the value of role models and prescribed mentors can be seen as an important influence in shaping the student's future as a diagnostic radiographer. A study was undertaken to create a new understanding of how diagnostic radiography students perceive role models and professional behavior in the workforce. The study aimed to determine the impact of clinical education in determining modeling expectations, role model identification and attributes, and the integration of academic education and "hands-on" clinical practice in preparing diagnostic radiography students to enter the workplace. Thirteen final-year (third-year) diagnostic radiography students completed an hour-long interview regarding their experiences and perceptions of role models while on clinical placement. The key concepts that emerged illustrated that students gravitate toward radiographers who enjoy sharing practical experiences with students and are good communicators. Unique to diagnostic radiography, students made distinctions about the presence of role models in private versus public service delivery. This study gives insight to clinical educators in diagnostic radiography and wider allied health into how students perceive role models, interact with preceptors, and combine real-life experiences with formal learning.

Internal anatomy of the hornbill casque described by radiography, contrast radiography, and computed tomography.

PubMed

Gamble, Kathryn C

2007-03-01

Hornbills are distinguished from most other avian taxa by the presence of a casque on the dorsal maxillary beak, which, in all but 1 of the 54 extant hornbill species, is described as essentially an air-filled cavity enclosed by minimal cancellous bone. The external casque has been described in detail, but little has been described about its internal anatomy and the communications between the casque and the paranasal sinuses. In this study, 10 intact casque and skull specimens of 7 hornbill species were collected opportunistically at necropsy. The anatomy of the casque and the skull for each of the specimens was examined by radiography, contrast radiography, and computed tomography. After imaging, 8 specimens were submitted for osteologic preparation to directly visualize the casque and the skull interior. Through this standardized review, the baseline anatomy of the internal casque was described, including identification of a novel casque sinus within the paranasal sinus system. These observations will assist clinicians in the diagnosis and treatment of diseases of the casque in hornbill species.

Repeat rates in digital chest radiography and strategies for improvement.

PubMed

Fintelmann, Florian; Pulli, Benjamin; Abedi-Tari, Faezeh; Trombley, Maureen; Shore, Mary-Theresa; Shepard, Jo-Anne; Rosenthal, Daniel I

2012-05-01

To determine the repeat rate (RR) of chest radiographs acquired with portable computed radiography (CR) and installed direct radiography (DR) and to develop and assess strategies designed to decrease the RR. The RR and reasons for repeated digital chest radiographs were documented over the course of 16 months while a task force of thoracic radiologists, technologist supervisors, technologists, and information technology specialists continued to examine the workflow for underlying causes. Interventions decreasing the RR were designed and implemented. The initial RR of digital chest radiographs was 3.6% (138/3818) for portable CR and 13.3% (476/3575) for installed DR systems. By combining RR measurement with workflow analysis, targets for technical and teaching interventions were identified. The interventions decreased the RR to 1.8% (81/4476) for portable CR and to 8.2% (306/3748) for installed DR. We found the RR of direct digital chest radiography to be significantly higher than that of computed chest radiography. We believe this is due to the ease with which repeat images can be obtained and discarded, and it suggests the need for ongoing surveillance of RR. We were able to demonstrate that strategies to lower the RR, which had been developed in the era of film-based imaging, can be adapted to the digital environment. On the basis of our findings, we encourage radiologists to assess their own departmental RRs for direct digital chest radiography and to consider similar interventions if necessary to achieve acceptable RRs for this modality.

Radiography Students' Learning: A Literature Review.

PubMed

Holmström, Anneli; Ahonen, Sanna-Mari

2016-01-01

To describe research methodology and findings concerning radiography students' learning. Health sciences databases were searched to perform a traditional narrative literature review. Thirty-five peer-reviewed articles published between 2000 and 2014 were analyzed using thematic analysis. Specific methods of learning were found to be of the most interest. The studies focused primarily on the use and usability of a method or the students' general experiences of it. The most commonly studied methods were e-learning and interprofessional learning, which students perceived as positive methods for theoretical studies and clinical training. Students' learning regarding research was the focus of only one article reporting a wide variety of students' research interests. Most studies reported quantitative research gathered from questionnaires and surveys. Additional research, especially from a qualitative point of view, is needed to deepen the evidence-based knowledge of radiography student learning.

Simple methods to reduce patient exposure during scoliosis radiography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Butler, P.F.; Thomas, A.W.; Thompson, W.E.

1986-05-01

Radiation exposure to the breasts of adolescent females can be reduced significantly through the use of one or all of the following methods: fast, rare-earth screen-film combinations; specially designed compensating filters; and breast shielding. The importance of exposure reduction during scoliosis radiography as well as further details on the above described methods are discussed. In addition, the early results of a Center for Devices and Radiological Health study, which recorded exposure and technique data for scoliosis radiography, is presented.

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

PubMed

Ecochard-Dugelay, Emmanuelle; Beliah, Muriel; Boisson, Caroline; Perreaux, Francis; de Laveaucoupet, Jocelyne; Labrune, Philippe; Epaud, Ralph; Ducou-Lepointe, Hubert; Bouyer, Jean; Gajdos, Vincent

2014-01-01

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

Repetitive compact flash x-ray generators for soft radiography

NASA Astrophysics Data System (ADS)

Sato, Eiichi; Shikoda, Arimitsu; Kimura, Shingo; Sagae, Michiaki; Oizumi, Teiji; Takahashi, Kei; Hayasi, Yasuomi; Shoji, Tetsuo; Shishido, Koro; Tamakawa, Yoshiharu; Yanagisawa, Toru

1993-01-01

The construction and the fundamental studies for the repetitive flash x-ray generators designed by Japan Impulse Laboratory in Iwate Medical University are described. These generators are classified to the following two major types: (1) generators having diodes, and (2) generators having triodes. In order to generate high-voltage impulses, we employed the following transmission lines (pulsers): (a) high-voltage-inversion type with a maximum output voltage Vom of about 80 kV, (b) high-voltage- inversion type having a coaxial cable (Vom equals 130 kV), (c) two-stage Marx pulser (Vom equals 150 kV), (d) two-cable-type Blumlein (Vom equals 120 kV), (e) modified Blumlein (Vom equals 120 kV), (f) fundamental transmission line for triode (Vom equals 100 kV), and (g) transmission line for an enclosed triode (Vom equals 100 kV). Using these generators we succeeded in performing high-speed radiography as follows: (a) delayed radiography; (b) multiple-shot radiography; and (c) cineradiography.

Plain abdominal radiography in acute abdominal pain; past, present, and future

PubMed Central

Gans, Sarah L; Stoker, Jaap; Boermeester, Marja A

2012-01-01

Several studies have demonstrated that a diagnosis based solely on a patient’s medical history, physical examination, and laboratory tests is not reliable enough, despite the fact that these aspects are essential parts of the workup of a patient presenting with acute abdominal pain. Traditionally, imaging workup starts with abdominal radiography. However, numerous studies have demonstrated low sensitivity and accuracy for plain abdominal radiography in the evaluation of acute abdominal pain as well as various specific diseases such as perforated viscus, bowel obstruction, ingested foreign body, and ureteral stones. Computed tomography, and in particular computed tomography after negative ultrasonography, provides a better workup than plain abdominal radiography alone. The benefits of computed tomography lie in decision-making for management, planning of a surgical strategy, and possibly even avoidance of negative laparotomies. Based on abundant available evidence, major advances in diagnostic imaging, and changes in the management of certain diseases, we can conclude that there is no place for plain abdominal radiography in the workup of adult patients with acute abdominal pain presenting in the emergency department in current practice. PMID:22807640

Adherence to radiography guidelines for low back pain: a survey of chiropractic schools worldwide.

PubMed

Ammendolia, Carlo; Taylor, John A M; Pennick, Victoria; Côté, Pierre; Hogg-Johnson, Sheilah; Bombardier, Claire

2008-01-01

This study describes instruction provided at chiropractic schools worldwide on the use of spine radiography and compares instruction with evidence-based guidelines for low back pain. Individuals responsible for radiology instruction at accredited chiropractic schools throughout the world were contacted and invited to participate in a Web-based survey. The survey included questions on the role of conventional radiography in chiropractic practice and instruction given to students for its use in patients with acute low back pain. Of the 33 chiropractic schools identified worldwide, 32 (97%) participated in the survey. Consistent with the guidelines, 25 (78%) respondents disagreed that "routine radiography should be used prior to spinal manipulative therapy," 29 (91%) disagreed that there "was a role for full spine radiography for assessing patients with low back pain," and 29 (91%) disagreed that "oblique views should be part of a standard radiographic series for low back pain." However, only 14 (44%) respondents concurred with the guidelines and disagreed with the statement that there "is a role for radiography in acute low back pain in the absence of 'red flags' for serious disease." This survey suggests that many aspects of radiology instruction provided by accredited chiropractic schools appear to be evidence based. However, there appears to be a disparity between some schools and existing evidence with respect to the role of radiography for patients with acute low back pain without "red flags" for serious disease. This may contribute to chiropractic overutilization of radiography for low back pain.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Snaith, Beverly A

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

Reduction of radiation exposure during radiography for scoliosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gray, J.E.; Hoffman, A.D.; Peterson, H.A.

1983-01-01

To reduce the radiation exposure received by young scoliosis patients during treatment, six changes in technique were instituted: (1) a posteroanterior projection, (2) specially designed leaded acrylic filters, (3) a high-speed screen-film system, (4) a specially designed cassette-holder and grid, (5) a breast-shield, and (6) additional filtration in the x-ray tube the thyroid, breast, and abdominal areas were made on an Alderson phantom. They revealed an eightfold reduction in abdominal exposure for both the posteroanterior and the lateral radiographys. There was a twentyfold reduction in exposure to the thyroid for the posteroanterior radiography from 100 to less than five milliroentgensmore » and for the lateral radiograph there was a 100-fold reduction from 618 to six milliroentgens. For the breasts there was a sixty-ninefold reduction from 344 to less than five milliroentgens for the posteroanterior radiography and a fifty-fivefold reduction from 277 to less than five milliroentgens for the lateral radiograph. These reductions in exposure were obtained without significant loss in the quality of the radiographs and in most instances with an improvement in the over-all quality of the radiograph due to the more uniform exposure.« less

Electron radiography

DOEpatents

Merrill, Frank E.; Morris, Christopher

2005-05-17

A system capable of performing radiography using a beam of electrons. Diffuser means receive a beam of electrons and diffuse the electrons before they enter first matching quadrupoles where the diffused electrons are focused prior to the diffused electrons entering an object. First imaging quadrupoles receive the focused diffused electrons after the focused diffused electrons have been scattered by the object for focusing the scattered electrons. Collimator means receive the scattered electrons and remove scattered electrons that have scattered to large angles. Second imaging quadrupoles receive the collimated scattered electrons and refocus the collimated scattered electrons and map the focused collimated scattered electrons to transverse locations on an image plane representative of the electrons' positions in the object.

Pilot Study of Bovine Interdigital Cassetteless Computed Radiography

PubMed Central

EL-SHAFAEY, El-Sayed Ahmed Awad; AOKI, Takahiro; ISHII, Mitsuo; YAMADA, Kazutaka

2013-01-01

ABSTRACT Twenty-one limbs of bovine cadavers (42 digits) were exposed to interdigital cassetteless imaging plate using computed radiography. The radiographic findings included exostosis, a rough planta surface, osteolysis of the apex of the distal phalanx and widening of the laminar zone between the distal phalanx and the hoof wall. All these findings were confirmed by computed tomography. The hindlimbs (19 digits) showed more changes than the forelimbs (10 digits), particularly in the lateral distal phalanx. The cassetteless computed radiography technique is expected to be an easily applicable method for the distal phalanx rather than a conventional cassette-plate and/or the film-screen cassetteless methods. PMID:23782542

Impact of digital radiography on clinical workflow.

PubMed

May, G A; Deer, D D; Dackiewicz, D

2000-05-01

It is commonly accepted that digital radiography (DR) improves workflow and patient throughput compared with traditional film radiography or computed radiography (CR). DR eliminates the film development step and the time to acquire the image from a CR reader. In addition, the wide dynamic range of DR is such that the technologist can perform the quality-control (QC) step directly at the modality in a few seconds, rather than having to transport the newly acquired image to a centralized QC station for review. Furthermore, additional workflow efficiencies can be achieved with DR by employing tight radiology information system (RIS) integration. In the DR imaging environment, this provides for patient demographic information to be automatically downloaded from the RIS to populate the DR Digital Imaging and Communications in Medicine (DICOM) image header. To learn more about this workflow efficiency improvement, we performed a comparative study of workflow steps under three different conditions: traditional film/screen x-ray, DR without RIS integration (ie, manual entry of patient demographics), and DR with RIS integration. This study was performed at the Cleveland Clinic Foundation (Cleveland, OH) using a newly acquired amorphous silicon flat-panel DR system from Canon Medical Systems (Irvine, CA). Our data show that DR without RIS results in substantial workflow savings over traditional film/screen practice. There is an additional 30% reduction in total examination time using DR with RIS integration.

Comparison of the diagnostic value of ultrasonography and standing radiography for pelvic-femoral disorders in horses.

PubMed

Geburek, Florian; Rötting, Anna K; Stadler, Peter M

2009-04-01

To assess agreement between ultrasonography (transcutaneous and transrectal) and standing radiography in horses with fractures in the pelvic region and disorders of the coxofemoral joint. Case series. Warmblood horses (n=23) and 2 ponies. Medical records (1999-2008) of equids with pelvic or coxofemoral disorders that had pelvic radiography and ultrasonography were retrieved and results of both techniques compared. Radiography and ultrasonography each identified equal numbers of fractures of the tuber coxa (n=4), ilial shaft (2), ischium (3), femoral neck (2), and osteoarthritis/osis of the coxofemoral joint (6). Fractures of the ilial wing (4) were only identified by ultrasonography not by standing radiography. Of 9 acetabular fractures, 3 were identified on radiographs only, 5 were identified with both modalities. One pubic fracture was identified using ultrasonography and radiography. One acetabular and 1 pubic fracture were only diagnosed on necropsy. We found reasonable agreement (73%; 24/33) between ultrasonography and standing radiography for diagnosis of pelvic-femoral disorders. Ultrasonography was more useful for ilial wing fractures and radiography for acetabular fractures. Ultrasonography is a rapid, safe imaging technique for detecting disorders of the pelvic region with a high diagnostic yield and is a preferred initial approach in horses with severe hindlimb lameness.

Study of pipe thickness loss using a neutron radiography method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mohamed, Abdul Aziz; Wahab, Aliff Amiru Bin; Yazid, Hafizal B.

2014-02-12

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

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

PubMed

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

2007-09-01

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

First steps towards real-time radiography at the NECTAR facility

NASA Astrophysics Data System (ADS)

Bücherl, T.; Wagner, F. M.; v. Gostomski, Ch. Lierse

2009-06-01

The beam tube SR10 at Forschungsneutronenquelle Heinz Maier-Leibnitz (FRM II) provides an intense beam of fission neutrons for medical application (MEDAPP) and for radiography and tomography of technical and other objects (NECTAR). The high neutron flux of up to 9.8E+07 cm -2 s -1 (depending on filters and collimation) with a mean energy of about 1.9 MeV at the sample position at the NECTAR facility prompted an experimental feasibility study to investigate the potential for real-time (RT) radiography.

Detection failure rate of chest radiography for the identification of nursing and healthcare-associated pneumonia.

PubMed

Miyashita, Naoyuki; Kawai, Yasuhiro; Tanaka, Takaaki; Akaike, Hiroto; Teranishi, Hideto; Wakabayashi, Tokio; Nakano, Takashi; Ouchi, Kazunobu; Okimoto, Niro

2015-07-01

To clarify the detection failure rate of chest radiography for the identification of nursing and healthcare-associated pneumonia (NHCAP), we compared high-resolution computed tomography (HRCT) with chest radiography simultaneously for patients with clinical symptoms and signs leading to a suspicion of NHCAP. We analyzed 208 NHCAP cases and compared them based on four groups defined using NHCAP criteria, patients who were: Group A) resident in an extended care facility or nursing home; Group B) discharged from a hospital within the preceding 90 days; Group C) receiving nursing care and had poor performance status; and Group D) receiving regular endovascular treatment. Chest radiography was inferior to HRCT for the identification of pneumonia (149 vs 208 cases, p < 0.0001). Among the designated NHCAP criteria, chest radiography identified pneumonia cases at a significantly lower frequency than HRCT in Group A (70 vs 97 cases, p = 0.0190) and Group C (86 vs 136 cases, p < 0.0001). The detection failure rate of chest radiography differed among NHCAP criteria; 27.8% in Group A, 26.5% in Group B, 36.7% in Group C and 5.8% in Group D. Cerebrovascular disease and poor functional status were significantly more frequent in patients in Groups A and C compared with those in Groups B and D. Physicians may underestimate pneumonia shadow in chest radiographs in patients with NHCAP, and the detection failure rate of chest radiography differed among NHCAP criteria. Poor functional status may correlate with the low accuracy of chest radiography in diagnosing pneumonia. Copyright © 2015. Published by Elsevier Ltd.

Effect of Localizer Radiography Projection on Organ Dose at Chest CT with Automatic Tube Current Modulation.

PubMed

Saltybaeva, Natalia; Krauss, Andreas; Alkadhi, Hatem

2017-03-01

Purpose To calculate the effect of localizer radiography projections to the total radiation dose, including both the dose from localizer radiography and that from subsequent chest computed tomography (CT) with tube current modulation (TCM). Materials and Methods An anthropomorphic phantom was scanned with 192-section CT without and with differently sized breast attachments. Chest CT with TCM was performed after one localizer radiographic examination with anteroposterior (AP) or posteroanterior (PA) projections. Dose distributions were obtained by means of Monte Carlo simulations based on acquired CT data. For Monte Carlo simulations of localizer radiography, the tube position was fixed at 0° and 180°; for chest CT, a spiral trajectory with TCM was used. The effect of tube start angles on dose distribution was investigated with Monte Carlo simulations by using TCM curves with fixed start angles (0°, 90°, and 180°). Total doses for lungs, heart, and breast were calculated as the sum of the dose from localizer radiography and CT. Image noise was defined as the standard deviation of attenuation measured in 14 circular regions of interest. The Wilcoxon signed rank test, paired t test, and Friedman analysis of variance were conducted to evaluate differences in noise, TCM curves, and organ doses, respectively. Results Organ doses from localizer radiography were lower when using a PA instead of an AP projection (P = .005). The use of a PA projection resulted in higher TCM values for chest CT (P < .001) owing to the higher attenuation (P < .001) and thus resulted in higher total organ doses for all investigated phantoms and protocols (P < .001). Noise in CT images was lower with PA localizer radiography than with AP localizer radiography (P = .03). The use of an AP projection allowed for total dose reductions of 16%, 15%, and 12% for lungs, breast, and heart, respectively. Differences in organ doses were not related to tube start angles (P = .17). Conclusion The total

Effect of comfort pads and incubator design on neonatal radiography.

PubMed

Jiang, Xia; Baad, Michael; Reiser, Ingrid; Feinstein, Kate A; Lu, Zhengfeng

2016-01-01

There has been increasing interest in patient dose reduction in neonatal intensive care units. Removing comfort pads for radiography has been identified as a potential means to decrease patient dose. To assess the effect of comfort pads and support trays on detector entrance exposure (DEE) and image quality for neonatal radiography, and its implication for patient dose. Comfort pads and support trays from three incubator and warmer systems were examined. The attenuation of the primary beam by these structures was measured using a narrow beam geometry. Their effect on DEE and image quality was then assessed using typical neonatal chest radiography techniques with three configurations: 1) both the comfort pad and support included in the beam, 2) only the support tray included and 3) both the comfort pad and support tray removed. Comfort pads and support trays were found to attenuate the primary beam by 6-15%. Eliminating these structures from the X-ray beam's path was found to increase the detector entrance exposure by 28-36% and increase contrast-to-noise ratio by more than 21%, suggesting room for patient dose reduction when the same image quality is maintained. Comfort pads and tray support devices can have a considerable effect on DEE and image quality, with large variations among different incubator designs. Positioning the image detector directly underneath neonatal patients for radiography is a potential means for patient dose reduction. However, such benefit should be weighed against the risks of moving the patient.

Searching early bone metastasis on plain radiography by using digital imaging processing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jaramillo-Nunez, A.; Perez-Meza, M.; Universidad de la Sierra Sur, C. P. 70800, Miahuatlan, Oax.

2012-10-23

Some authors mention that it is not possible to detect early bone metastasis on plain radiography. In this work we use digital imaging processing to analyze three radiographs taken from a patient with bone metastasis discomfort on the right shoulder. The time period among the first and second radiography was approximately one month and between the first and the third one year. This procedure is a first approach in order to know if in this particular case it was possible to detect an early bone metastasis. The obtained results suggest that by carrying out a digital processing is possible tomore » detect the metastasis since the radiography contains the information although visually it is not possible to observe it.« less

[Detection of lung nodules. New opportunities in chest radiography].

PubMed

Pötter-Lang, S; Schalekamp, S; Schaefer-Prokop, C; Uffmann, M

2014-05-01

Chest radiography still represents the most commonly performed X-ray examination because it is readily available, requires low radiation doses and is relatively inexpensive. However, as previously published, many initially undetected lung nodules are retrospectively visible in chest radiographs. The great improvements in detector technology with the increasing dose efficiency and improved contrast resolution provide a better image quality and reduced dose needs. The dual energy acquisition technique and advanced image processing methods (e.g. digital bone subtraction and temporal subtraction) reduce the anatomical background noise by reduction of overlapping structures in chest radiography. Computer-aided detection (CAD) schemes increase the awareness of radiologists for suspicious areas. The advanced image processing methods show clear improvements for the detection of pulmonary lung nodules in chest radiography and strengthen the role of this method in comparison to 3D acquisition techniques, such as computed tomography (CT). Many of these methods will probably be integrated into standard clinical treatment in the near future. Digital software solutions offer advantages as they can be easily incorporated into radiology departments and are often more affordable as compared to hardware solutions.

Ultrafast table-top dynamic radiography of spontaneous or stimulated events

DOEpatents

Smilowitz, Laura; Henson, Bryan

2018-01-16

Disclosed herein are representative embodiments of methods, apparatus, and systems for performing radiography. For example, certain embodiments concern X-ray radiography of spontaneous events. Particular embodiments of the disclosed technology provide continuous high-speed x-ray imaging of spontaneous dynamic events, such as explosions, reaction-front propagation, and even material failure. Further, in certain embodiments, x-ray activation and data collection activation are triggered by the object itself that is under observation (e.g., triggered by a change of state detected by one or more sensors monitoring the object itself).

Implementation of a PACS for radiography training and clinical service in a university setting through a multinational effort

NASA Astrophysics Data System (ADS)

Tang, Fuk-hay; Law, Yuen Y.; Zhang, Jianguo; Liu, Hai L.; Chang, Tony; Matsuda, Koyo; Cao, Fei

2001-08-01

The Hong Kong Polytechnic University has a Radiography Division under the Development of Optometry and Radiography. The Division trains both diagnostic and therapeutic radiographers with 60 students/year and offers a B.Sc. degree. In addition the Division together with the University Health Service operates a radiography clinic with radiology consultation from radiologists from other hospitals and clinics. This paper describers the implementation of a PACS in the Division for radiography training, and for clinical service.

Digital radiography and electronic data storage from the perspective of legal requirements for record keeping.

PubMed

Figgener, L; Runte, C

2003-12-01

In some countries physicians and dentists are required by law to keep medical and dental records. These records not only serve as personal notes and memory aids but have to be in accordance with the necessary standard of care and may be used as evidence in litigation. Inadequate, incomplete or even missing records can lead to reversal of the burden of proof, resulting in a dramatically reduced chance of successful defence in litigation. The introduction of digital radiography and electronic data storage presents a new problem with respect to legal evidence, since digital data can easily be manipulated and industry is now required to provide adequate measures to prevent manipulations and forgery.

Thoracic radiography in the cat: Identification of cardiomegaly and congestive heart failure.

PubMed

Guglielmini, Carlo; Diana, Alessia

2015-12-01

Thoracic radiography is one of the most commonly employed diagnostic tools for the clinical evaluation of cats with suspected heart disease and is the standard diagnostic method in the confirmation of cardiogenic pulmonary edema. In the past, interpretation of feline radiographs focused on a description of the qualitative radiographic features of feline heart disease or the measurement of the cardiac silhouette in healthy cats and cats with different cardiovascular disorders. More recently, studies have begun to critically address the issue of the diagnostic accuracy of thoracic radiography in the diagnostic work-up of cats with heart disease. In these studies, qualitative and quantitative radiographic parameters were compared to echocardiographic findings to evaluate the usefulness of thoracic radiography for the identification of cardiac enlargement and pulmonary edema in the cat. Thoracic radiography is reasonably specific but has a low sensitivity when identifying cardiomegaly in cats with mild structural heart disease. Feline cardiogenic pulmonary edema has a variable radiographic presentation and several specific radiographic findings (i.e., enlargement of the left atrium and the pulmonary veins) can be absent or non-recognizable in affected cats. Copyright © 2015 Elsevier B.V. All rights reserved.

Radiography on wheels arrives to nursing homes - an economic assessment of a new health care technology in southern Sweden.

PubMed

Dozet, Alexander; Ivarsson, Bodil; Eklund, Karin; Klefsgård, Rosemarie; Geijer, Mats

2016-12-01

The process of transferring older, vulnerable adults from an elder care facility to the hospital for medical care can be an emotionally and physically stressful experience. The recent development of modern mobile radiography may help to ease this anxiety by allowing for evaluation in the nursing home itself. Up until this point, no health economic evaluation of the technology has been attempted in a Swedish setting. The objective of this study was to determine whether examinations of patients in elder care facilities with mobile radiography were cost-effective from a societal perspective compared with hospital-based radiological examinations. This prospective study included two groups of nursing home residents in two different areas in southern Sweden. All residents in the nursing homes were targeted for the study. Seventy-one patients were examined with hospital-based radiography at two hospitals, and 312 patients were examined using mobile radiography in nursing homes. Given that the diagnostic effects are regarded as equivalent, a cost minimization method was applied. Direct costs were estimated using prices from the county council, Region Skåne, Sweden. From a societal perspective, mobile radiography was shown to have significantly lower costs per examination compared with hospital-based radiography. The difference in health care-related costs was also significant in favour of mobile radiography. Mobile radiography can be used to examine patients in nursing homes at a lower cost than hospital-based radiography. Patients benefit from not having to transfer to a hospital for radiography, resulting in reduced anxiety for patients. © 2016 John Wiley & Sons, Ltd.

A comparison of digital tomosynthesis and chest radiography in evaluating airway lesions using computed tomography as a reference.

PubMed

Choo, Ji Yung; Lee, Ki Yeol; Yu, Ami; Kim, Je-Hyeong; Lee, Seung Heon; Choi, Jung Won; Kang, Eun-Young; Oh, Yu Whan

2016-09-01

To compare the diagnostic performance of digital tomosynthesis (DTS) and chest radiography for detecting airway abnormalities, using computed tomography (CT) as a reference. We evaluated 161 data sets from 149 patients (91 with and 70 without airway abnormalities) who had undergone radiography, DTS, and CT to detect airway problems. Radiographs and DTS were evaluated to localize and score the severity of the airway abnormalities, and to score the image quality using CT as a reference. Receiver operating characteristics (ROC), McNemar's test, weighted kappa, and the paired t-test were used for statistical analysis. The sensitivity of DTS was higher (reader 1, 93.51 %; reader 2, 94.29 %) than chest radiography (68.83 %; 71.43 %) in detecting airway lesions. The diagnostic accuracy of DTS (90.91 %; 94.70 %) was also significantly better than that of radiography (78.03 %; 82.58 %, all p < 0.05). DTS image quality was significantly better than chest radiography (1.83, 2.74; p < 0.05) in the results of both readers. The inter-observer agreement with respect to DTS findings was moderate and superior when compared to radiography findings. DTS is a more accurate and sensitive modality than radiography for detecting airway lesions that are easily obscured by soft tissue structures in the mediastinum. • Digital tomosynthesis offers new diagnostic options for airway lesions. • Digital tomosynthesis is more sensitive and accurate than radiography for airway lesions. • Digital tomosynthesis shows better image quality than radiography. • Assessment of lesion severity, via tomosynthesis is comparable to computed tomography.

Rib Radiography versus Chest Computed Tomography in the Diagnosis of Rib Fractures.

PubMed

Sano, Atsushi

2018-05-01

 The accurate diagnosis of rib fractures is important in chest trauma. Diagnostic images following chest trauma are usually obtained via chest X-ray, chest computed tomography, or rib radiography. This study evaluated the diagnostic characteristics of rib radiography and chest computed tomography.  Seventy-five rib fracture patients who underwent both chest computed tomography and rib radiography between April 2008 and December 2013 were included. Rib radiographs, centered on the site of pain, were taken from two directions. Chest computed tomography was performed using a 16-row multidetector scanner with 5-mm slice-pitch without overlap, and axial images were visualized in a bone window.  In total, 217 rib fractures were diagnosed in 75 patients. Rib radiography missed 43 rib fractures in 24 patients. The causes were overlap with organs in 15 cases, trivial fractures in 21 cases, and injury outside the imaging range in 7 cases. Left lower rib fractures were often missed due to overlap with the heart, while middle and lower rib fractures were frequently not diagnosed due to overlap with abdominal organs. Computed tomography missed 21 rib fractures in 17 patients. The causes were horizontal fractures in 10 cases, trivial fractures in 9 cases, and insufficient breath holding in 1 case.  In rib radiography, overlap with organs and fractures outside the imaging range were characteristic reasons for missed diagnoses. In chest computed tomography, horizontal rib fractures and insufficient breath holding were often responsible. We should take these challenges into account when diagnosing rib fractures. Georg Thieme Verlag KG Stuttgart · New York.

Use of radiography in acute knee injuries: need for clinical decision rules.

PubMed

Stiell, I G; Wells, G A; McDowell, I; Greenberg, G H; McKnight, R D; Cwinn, A A; Quinn, J V; Yeats, A

1995-11-01

To study: 1) the efficiency of the current use of radiography in acute knee injuries, 2) the judgments and attitudes of experienced clinicians in their use of knee radiography, and 3) the potential for decision rules to improve efficiency. This two-stage study of adults with acute knee injuries involved: 1) a retrospective review of all 1,967 patients seen over a 12-month period in the EDs of one community and two teaching hospital, and 2) a prospective survey of another 1,040 patients seen by attending emergency physicians. The prospective survey assessed each clinician's estimate of the probability of a knee or patella fracture; 120 patients were independently assessed by two physicians. Of the 1,967 patients seen in the first stage, 74.1% underwent radiography but only 5.2% were found to have fractures. Of the 1,727 knee and patella radiographic series ordered, 92.4% were negative for fracture. In the second stage, experienced physicians predicted the probability of fracture to be 0 or 0.1 for 75.6% of the patients. The kappa value for this response was 0.51 (95% CI 0.34 to 0.68). The physicians also indicated that they would have been comfortable or very comfortable in not ordering radiography for 55.5% of the patients. The area under the receiver operating characteristics curve for the physicians' prediction of fracture was 0.87 (95% CI 0.82 to 0.91), reflecting good discrimination between fracture and nonfracture cases. Likelihood ratios for the physicians' prediction ranged from 0.09 at the 0 level to 42.9 at the 0.9-1.0 level. Emergency physicians order radiography for most patients with acute knee injuries, even though they can accurately discriminate between fracture and nonfracture cases and expect most of the radiographs to be normal. These findings suggest great potential for more efficient use of knee radiography, possibly through the use of a clinical decision rule.

Emergency physicians' attitudes toward and use of clinical decision rules for radiography.

PubMed

Graham, I D; Stiell, I G; Laupacis, A; O'Connor, A M; Wells, G A

1998-02-01

1) To assess Canadian emergency physicians' (EPs') use of and attitudes toward 2 radiographic clinical decision rules that have recently been developed and to identify physician characteristics associated with decision rule use; 2) to determine the use of CT head and cervical spine radiography by EPs and their beliefs about the appropriateness of expert recommendations supporting the routine use of these radiographic procedures; and 3) to determine the potential acceptance of clinical decision rules for CT scan in patients with minor head injury and cervical spine radiography in trauma patients. A cross-sectional anonymous mail survey of a random sample of 300 members of the Canadian Association of Emergency Physicians using Dillman's Total Design Method for mail surveys. Of 288 eligible physicians, 232 (81%) responded. More than 95% of the respondents stated they currently used the Ottawa Ankle Rules and were willing to consider using the newly developed Ottawa Knee Rule. Physician characteristics related to frequent use of the Ottawa Ankle Rules were younger age, fewer years since graduating from medical school, part time or resident employment status, working in a hospital without a CT scanner, and believing that decision rules are not oversimplified cookbook medicine or too rigid to apply. Eighty-five percent did not agree that all patients with minor head injuries should receive a CT head scan and only 3.5% stated they always refer such patients for CT scan. Similarly, 78.5% of the respondents did not agree that all trauma patients should receive cervical spine radiography and only 13.2% said they always refer such patients for cervical spine radiography. Ninety-seven and 98% stated they would be willing to consider using well-validated decision rules for CT scan of the head and cervical spine radiography, respectively. Fifty-two percent and 67% of the respondents required the proposed CT and C-spine to be 100% sensitive for identifying serious injuries

Infection control practices for dental radiography.

PubMed

Palenik, Charles John

2004-06-01

Infection control for dental radiography employs the same materials, processes, and techniques used in the operatory, yet unless proper procedures are established and followed, there is a definite potential for cross-contamination to clinical area surfaces and DHCP. In general, the aseptic practices used are relatively simple and inexpensive, yet they require complete application in every situation.

Intramodality and intermodality agreement in radiography and computed tomography of equine distal limb fractures.

PubMed

Crijns, C P; Martens, A; Bergman, H-J; van der Veen, H; Duchateau, L; van Bree, H J J; Gielen, I M V L

2014-01-01

Computed tomography (CT) is increasingly accessible in equine referral hospitals. To document the level of agreement within and between radiography and CT in characterising equine distal limb fractures. Retrospective descriptive study. Images from horses that underwent radiographic and CT evaluation for suspected distal limb fractures were reviewed, including 27 horses and 3 negative controls. Using Cohen's kappa and weighted kappa analysis, the level of agreement among 4 observers for a predefined set of diagnostic characteristics for radiography and CT separately and for the level of agreement between the 2 imaging modalities were documented. Both CT and radiography had very good intramodality agreement in identifying fractures, but intermodality agreement was lower. There was good intermodality and intramodality agreement for anatomical localisation and the identification of fracture displacement. Agreement for articular involvement, fracture comminution and fracture fragment number was towards the lower limit of good agreement. There was poor to fair intermodality agreement regarding fracture orientation, fracture width and coalescing cracks; intramodality agreement was higher for CT than for radiography for these features. Further studies, including comparisons with surgical and/or post mortem findings, are required to determine the sensitivity and specificity of CT and radiography in the diagnosis and characterisation of equine distal limb fractures. © 2013 EVJ Ltd.

Investigating the use of an antiscatter grid in chest radiography for average adults with a computed radiography imaging system

PubMed Central

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

2015-01-01

Objective: The aim of this study was to investigate via simulation a proposed change to clinical practice for chest radiography. The validity of using a scatter rejection grid across the diagnostic energy range (60–125 kVp), in conjunction with appropriate tube current–time product (mAs) for imaging with a computed radiography (CR) system was investigated. Methods: A digitally reconstructed radiograph algorithm was used, which was capable of simulating CR chest radiographs with various tube voltages, receptor doses and scatter rejection methods. Four experienced image evaluators graded images with a grid (n = 80) at tube voltages across the diagnostic energy range and varying detector air kermas. These were scored against corresponding images reconstructed without a grid, as per current clinical protocol. Results: For all patients, diagnostic image quality improved with the use of a grid, without the need to increase tube mAs (and therefore patient dose), irrespective of the tube voltage used. Increasing tube mAs by an amount determined by the Bucky factor made little difference to image quality. Conclusion: A virtual clinical trial has been performed with simulated chest CR images. Results indicate that the use of a grid improves diagnostic image quality for average adults, without the need to increase tube mAs, even at low tube voltages. Advances in knowledge: Validated with images containing realistic anatomical noise, it is possible to improve image quality by utilizing grids for chest radiography with CR systems without increasing patient exposure. Increasing tube mAs by an amount determined by the Bucky factor is not justified. PMID:25571914

Comparison of Digital Imaging Systems for Neutron Radiography

NASA Astrophysics Data System (ADS)

Pugliesi, R.; Pugliesi, Fábio; Stanojev Pereira, M. A.

2011-09-01

The characteristics of three digital imaging systems for neutron radiography purposes have been compared. Two of them make use of films, CR-39 and Kodak AA, and the third makes use of a LiF scintillator, for image registration. The irradiations were performed in the neutron radiography facility installed at the IEA-R1 nuclear research reactor of IPEN-CNEN/SP. According to the obtained results, the system based on CR-39 is the slowest to obtain an image, and the best in terms of resolution but the worse in terms of contrast. The system based on Kodak AA is faster than the prior, exhibits good resolution and contrast. The system based on the scintillator is the fastest to obtain an image, and best in terms of contrast but the worse in terms of resolution.

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

PubMed

Yamada, Yoshitake; Jinzaki, Masahiro; Hashimoto, Masahiro; Shiomi, Eisuke; Abe, Takayuki; Kuribayashi, Sachio; Ogawa, Kenji

2013-08-01

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

Use of digital abdominal radiography for the diagnosis of enterolithiasis in equids: 238 cases (2008-2011).

PubMed

Kelleher, Maureen E; Puchalski, Sarah M; Drake, Christiana; le Jeune, Sarah S

2014-07-01

To evaluate the sensitivity and specificity of direct digital abdominal radiography for the diagnosis of enterolithiasis in equids and to assess the effect of the number and anatomic location of enteroliths and gas distention of the gastrointestinal tract on diagnostic sensitivity of the technique. Retrospective case series. 238 horses and ponies ≥ 1 year old that underwent digital abdominal radiography with subsequent exploratory celiotomy or postmortem examination. For each case, 3 reviewers independently evaluated radiographic views. Radiographic images were evaluated for presence or absence and location of enteroliths and the degree of gas distention. Signalment, definitive diagnosis based on exploratory celiotomy or postmortem examination findings, and number and anatomic location of enteroliths were obtained from the medical records. 70 of the 238 (29.4%) equids had confirmed enterolithiasis. With regard to diagnosis of enterolithiasis via digital radiography, overall sensitivity and specificity for the 3 reviewers were 84% and 96%, respectively. Sensitivity was lower for small colon enteroliths (61.5%) than for large colon enteroliths (88.9%) and was negatively affected by gas distention of the gastrointestinal tract. Sensitivity was not affected by the number of enteroliths. Sensitivity and specificity of digital radiography for the diagnosis of large colon enterolithiasis in equids was high. Sensitivity of digital radiography for detection of small colon enteroliths was lower than that for large colon enteroliths, but was higher than that typically associated with computed radiography. In geographic regions in which enterolithiasis in equids is endemic, digital abdominal radiography could be used as a diagnostic test for equids with colic.

Patient doses from chest radiography in Victoria.

PubMed

Cardillo, I; Boal, T J; Einsiedel, P F

1997-06-01

This survey examines doses from PA chest radiography at radiology practices, private hospitals and public hospitals throughout metropolitan and country Victoria. Data were collected from 111 individual X-ray units at 86 different practices. Entrance skin doses in air were measured for exposure factors used by the centre for a 23 cm thick male chest. A CDRH LucA1 chest phantom was used when making these measurements. About half of the centres used grid technique and half used non-grid technique. There was a factor of greater than 10 difference in the entrance dose delivered between the highest dose centre and the lowest dose centre for non-grid centres; and a factor of about 5 for centres using grids. Factors contributing to the high doses recorded at some centres were identified. Guidance levels for chest radiography based on the third quartile value of the entrance doses from this survey have been recommended and compared with guidance levels recommended in other countries.

Electrode Slurry Particle Density Mapping Using X-ray Radiography

DOE PAGES

Higa, Kenneth; Zhao, Hui; Parkinson, Dilworth Y.; ...

2017-01-05

The internal structure of a porous electrode strongly influences battery performance. Understanding the dynamics of electrode slurry drying could aid in engineering electrodes with desired properties. For instance, one might monitor the dynamic, spatially-varying thickness near the edge of a slurry coating, as it should lead to non-uniform thickness of the dried film. This work examines the dynamic behavior of drying slurry drops consisting of SiO x and carbon black particles in a solution of carboxymethylcellulose and deionized water, as an experimental model of drying behavior near the edge of a slurry coating. An X-ray radiography-based procedure is developed tomore » calculate the evolving spatial distribution of active material particles from images of the drying slurry drops. To the authors’ knowledge, this study is the first to use radiography to investigate battery slurry drying, as well as the first to determine particle distributions from radiography images of drying suspensions. The dynamic results are consistent with tomography reconstructions of the static, fully-dried films. It is found that active material particles can rapidly become non-uniformly distributed within the drops. Heating can promote distribution uniformity, but seemingly must be applied very soon after slurry deposition. Higher slurry viscosity is found to strongly restrain particle redistribution.« less

High Resolution Neutron Radiography and Tomography of Hydrided Zircaloy-4 Cladding Materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Tyler S; Bilheux, Hassina Z; Ray, Holly B

2015-01-01

Neutron radiography for hydrogen analysis was performed with several Zircaloy-4 cladding samples with controlled hydrogen concentrations up to 1100 ppm. Hydrogen charging was performed in a process tube that was heated to facilitate hydrogen absorption by the metal. A correlation between the hydrogen concentration in the hydrided tubes and the neutron intensity was established, by which hydrogen content can be determined precisely in a small area (55 m x 55 m). Radiography analysis was also performed to evaluate the heating rate and its correlation with the hydrogen distribution through hydrided materials. In addition to radiography analysis, tomography experiments were performedmore » on Zircaloy-4 tube samples to study the local hydrogen distribution. Through tomography analysis a 3D reconstruction of the tube was evaluated in which an uneven hydrogen distribution in the circumferential direction can be observed.« less

Spatial resolution measurements of the advanced radiographic capability x-ray imaging system at energies relevant to Compton radiography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hall, G. N.; Izumi, N.; Landen, O. L.

2016-08-03

Compton radiography provides a means to measure the integrity, ρR and symmetry of the DT fuel in an inertial confinement fusion implosion near peak compression. Upcoming experiments at the National Ignition Facility will use the ARC (Advanced Radiography Capability) laser to drive backlighter sources for Compton radiography experiments, and will use the newly commissioned AXIS (ARC X-ray Imaging System) instrument as the detector. AXIS uses a dual-MCP (micro channel plate) to provide gating and high DQE at the 40–200keV x-ray range required for Compton radiography, but introduces many effects that contribute to the spatial resolution. Here, experiments were performed atmore » energies relevant to Compton radiography to begin characterization of the spatial resolution of the AXIS diagnostic.« less

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.

PubMed

Dietrich, Tobias J; Pfirrmann, Christian W A; Schwab, Alexander; Pankalla, Katja; Buck, Florian M

2013-07-01

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.

Dual Use Corrosion Inhibitor and Penetrant for Anomaly Detection in Neutron/X Radiography

NASA Technical Reports Server (NTRS)

Hall, Phillip B. (Inventor); Novak, Howard L. (Inventor)

2004-01-01

A dual purpose corrosion inhibitor and penetrant composition sensitive to radiography interrogation is provided. The corrosion inhibitor mitigates or eliminates corrosion on the surface of a substrate upon which the corrosion inhibitor is applied. In addition, the corrosion inhibitor provides for the attenuation of a signal used during radiography interrogation thereby providing for detection of anomalies on the surface of the substrate.

Retrospective comparison of abdominal ultrasonography and radiography in the investigation of feline abdominal disease

PubMed Central

Won, Wylen Wade; Sharma, Ajay; Wu, Wenbo

2015-01-01

Abdominal radiography and ultrasonography are commonly used as part of the initial diagnostic plan for cats with nonspecific signs of abdominal disease. This retrospective study compared the clinical usefulness of abdominal radiography and ultrasonography in 105 feline patients with signs of abdominal disease. The final diagnosis was determined more commonly with ultrasonography (59%) compared to radiography (25.7%). Ultrasonography was also able to provide additional clinically relevant information in 76% of cases, and changed or refined the diagnosis in 47% of cases. Based on these findings, ultrasonography may be sufficient as an initial diagnostic test for the investigation of feline abdominal disease. PMID:26483582

Impact of Clinical Decision Support on Radiography for Acute Ankle Injuries: A Randomized Trial

PubMed Central

Tajmir, Shahein; Raja, Ali S.; Ip, Ivan K.; Andruchow, James; Silveira, Patricia; Smith, Stacy; Khorasani, Ramin

2017-01-01

Introduction While only 15–20% of patients with foot and ankle injuries presenting to urgent care centers have clinically significant fractures, most undergo radiography. We examined the impact of electronic point-of-care clinical decision support (CDS) on adherence to the Ottawa Ankle Rules (OAR), as well as use and yield of foot and ankle radiographs in patients with acute ankle injury. Methods We obtained institutional review board approval for this randomized controlled study performed April 18, 2012—December 15, 2013. All ordering providers credentialed at an urgent care affiliated with a quaternary care academic hospital were randomized to either receive or not receive CDS, based on the OAR and integrated into the physician order-entry system, with feedback at the time of imaging order. If the patient met OAR low-risk criteria, providers were advised against imaging and could either cancel the order or ignore the alert. We identified patients with foot and ankle complaints via ICD-9 billing codes and electronic health records and radiology reports reviewed for those who were eligible. Chi-square was used to compare adherence to the OAR (primary outcome), radiography utilization rate and radiography yield of foot and ankle imaging (secondary outcomes) between the intervention and control groups. Results Of 14,642 patients seen at urgent care during the study period, 613 (4.2%, representing 632 visits) presented with acute ankle injury and were eligible for application of the OAR; 374 (59.2%) of these were seen by control-group providers. In the intervention group, CDS adherence was higher for both ankle (239/258=92.6% vs. 231/374=61.8%, p=0.02) and foot radiography (209/258=81.0% vs. 238/374=63.6%; p<0.01). However, ankle radiography use was higher in the intervention group (166/258=64.3% vs. 183/374=48.9%; p<0.01), while foot radiography use (141/258=54.6% vs. 202/374=54.0%; p=0.95) was not. Radiography yield was also higher in the intervention group (26

Can Chest Computed Tomography Be Replaced by Lung Ultrasonography With or Without Plain Chest Radiography in Pediatric Pneumonia?

PubMed

Hajalioghli, Parisa; Nemati, Masoud; Dinparast Saleh, Leila; Fouladi, Daniel F

2016-07-01

The purpose of this study was to answer the following question: can chest computed tomography (CT) requested by pediatricians be replaced by lung ultrasonography (US) with or without chest radiography in pediatric pneumonia? A total of 98 children with suspected pneumonia who were referred by pediatricians for CT examinations were prospectively studied. Levels of agreement between CT findings and plain radiography, lung US, and chest radiography plus lung US results were investigated. CT defined pneumonia in 84 patients, among which 26 cases were complicated. κ values between radiography and CT findings were 0.82 in complicated cases, 0.67 in uncomplicated cases, and 0.72 overall. The corresponding values between US and CT findings were 1, 0.52, and 0.62, respectively, and between radiography plus US and CT findings were 1, 0.86, and 0.88, respectively. CT can be replaced by US when complex effusions are present in children with pneumonia. In case of an ambiguous diagnosis of pediatric pneumonia with or without complex effusions, a combination of chest radiography and US is a reliable surrogate for chest CT.

The frequency of various indications for plain chest radiography in Nnamdi Azikiwe University Teaching Hospital, Nnewi (NAUTH).

PubMed

Okpala, O C; Okafor, C; Aronu, M E

2013-01-01

With soaring advances in the field of medicine, the place of older radiologic imaging modalities is being reduced to basic screening tools. Yet the modern imaging modalities like computerized tomography (CT), magnetic resonance imaging (MRI), ultrasound and nuclear medicine are hardly available. To study the frequency of various indications of plain chest radiography, remind us of its uses and to enhance the preparedness of the department to maximally accomplish the ideals of this investigation. A total of 1476 consecutive patients for chest radiography in the department of radiology, NAUTH, Nnewi from the period of February 2009 and whose request form contain adequate data were recruited for this study. These data were analyzed using SSPS. A total of 1476 patient were included in this study. There was female preponderance with male to female ratio of 1.3:1. Mean Age of the patients is 39.32 years (std19.56). The most frequent indication for chest radiography is certain infections and parasitic diseases (40.9% and the greatest source of referral for this study is General outpatient (GOPD)/family medicine department. The most frequent indications for chest radiography in the study are certain infection and parasitic diseases. Chest Radiography is the most frequent plain radiography study in our environment where infectious diseases are still very rampant. This makes chest radiography an important study for screening patient for possible diagnosis and classifying the need for further radiographic investigation of our patients.

Registration of pencil beam proton radiography data with X-ray CT.

PubMed

Deffet, Sylvain; Macq, Benoît; Righetto, Roberto; Vander Stappen, François; Farace, Paolo

2017-10-01

Proton radiography seems to be a promising tool for assessing the quality of the stopping power computation in proton therapy. However, range error maps obtained on the basis of proton radiographs are very sensitive to small misalignment between the planning CT and the proton radiography acquisitions. In order to be able to mitigate misalignment in postprocessing, the authors implemented a fast method for registration between pencil proton radiography data obtained with a multilayer ionization chamber (MLIC) and an X-ray CT acquired on a head phantom. The registration was performed by optimizing a cost function which performs a comparison between the acquired data and simulated integral depth-dose curves. Two methodologies were considered, one based on dual orthogonal projections and the other one on a single projection. For each methodology, the robustness of the registration algorithm with respect to three confounding factors (measurement noise, CT calibration errors, and spot spacing) was investigated by testing the accuracy of the method through simulations based on a CT scan of a head phantom. The present registration method showed robust convergence towards the optimal solution. For the level of measurement noise and the uncertainty in the stopping power computation expected in proton radiography using a MLIC, the accuracy appeared to be better than 0.3° for angles and 0.3 mm for translations by use of the appropriate cost function. The spot spacing analysis showed that a spacing larger than the 5 mm used by other authors for the investigation of a MLIC for proton radiography led to results with absolute accuracy better than 0.3° for angles and 1 mm for translations when orthogonal proton radiographs were fed into the algorithm. In the case of a single projection, 6 mm was the largest spot spacing presenting an acceptable registration accuracy. For registration of proton radiography data with X-ray CT, the use of a direct ray-tracing algorithm to compute

Flash radiography with 24 GeV/c protons

NASA Astrophysics Data System (ADS)

Morris, C. L.; Ables, E.; Alrick, K. R.; Aufderheide, M. B.; Barnes, P. D.; Buescher, K. L.; Cagliostro, D. J.; Clark, D. A.; Clark, D. J.; Espinoza, C. J.; Ferm, E. N.; Gallegos, R. A.; Gardner, S. D.; Gomez, J. J.; Greene, G. A.; Hanson, A.; Hartouni, E. P.; Hogan, G. E.; King, N. S. P.; Kwiatkowski, K.; Liljestrand, R. P.; Mariam, F. G.; Merrill, F. E.; Morgan, D. V.; Morley, K. B.; Mottershead, C. T.; Murray, M. M.; Pazuchanics, P. D.; Pearson, J. E.; Sarracino, J. S.; Saunders, A.; Scaduto, J.; Schach von Wittenau, A. E.; Soltz, R. A.; Sterbenz, S.; Thompson, R. T.; Vixie, K.; Wilke, M. D.; Wright, D. M.; Zumbro, J. D.

2011-05-01

The accuracy of density measurements and position resolution in flash (40 ns) radiography of thick objects with 24 Gev/c protons is investigated. A global model fit to step wedge data is shown to give a good description spanning the periodic table. The parameters obtained from the step wedge data are used to predict transmission through the French Test Object (FTO), a test object of nested spheres, to a precision better than 1%. Multiple trials have been used to show that the systematic errors are less than 2%. Absolute agreement between the average radiographic measurements of the density and the known density is 1%. Spatial resolution has been measured to be 200 μm at the center of the FTO. These data verify expectations of the benefits provided by high energy hadron radiography for thick objects.

Comparison of radiography and ultrasonography for the diagnosis of osteochondritis dissecans in the equine femoropatellar joint.

PubMed

Bourzac, C; Alexander, K; Rossier, Y; Laverty, S

2009-09-01

Osteochondritis dissecans (OCD) lesions of the femoropatellar (FP) joint are diagnosed routinely by radiography, but lesions located in the trochlear groove or without accompanying subchondral bone changes can be difficult to visualise. Ultrasonography allows evaluation of articular cartilage and subchondral bone in the FPjoint. To document the radiographic and ultrasonographic appearance of OCD lesions in the equine FP joint, grade ultrasonographic lesions and compare their accuracy in the diagnosis of these lesions. The medical records of all horses diagnosed with FP OCD between 1995 and 2006 were assessed. Inclusion criteria included availability of both radiographic and ultrasonographic images. Lesion characteristics were evaluated in each trochlear ridge and trochlear groove. For assessment of the accuracy (sensitivity and specificity) of both imaging techniques in the diagnosis of OCD, only cases with an arthroscopic or necropsy examination were studied. Twenty-one horses were included. OCD lesions were diagnosed by radiography (30/32 joints) and ultrasound (32/32 joints). The lateral trochlear ridge (LTR, 91%) and the medial trochlear ridge (MTR, 17%) were involved on radiography. The localisation on ultrasound examination was similar (97% LTR, 25% MTR). All but one lesion seen on radiography were also detected with ultrasound; 2 LTR and 3 MTR lesions, not seen on radiography were diagnosed by ultrasound and confirmed at arthroscopy or necropsy. The specificity was 100% regardless of the site and imaging procedure except for the distal third of the MTR (94% for ultrasound). The sensitivity varied, depending on lesion site. Ultrasonography is a valuable diagnostic tool to diagnose OCD lesions in the FP joint and more sensitive than radiography for lesions affecting the MTR of the distal femur. Ultrasound should be considered as a useful adjunct to radiography for diagnosing equine FP OCD, especially in cases of high clinical suspicion but equivocal

Correlation of the clinical and physical image quality in chest radiography for average adults with a computed radiography imaging system.

PubMed

Moore, C S; Wood, T J; Beavis, A W; Saunderson, J R

2013-07-01

The purpose of this study was to examine the correlation between the quality of visually graded patient (clinical) chest images and a quantitative assessment of chest phantom (physical) images acquired with a computed radiography (CR) imaging system. The results of a previously published study, in which four experienced image evaluators graded computer-simulated postero-anterior chest images using a visual grading analysis scoring (VGAS) scheme, were used for the clinical image quality measurement. Contrast-to-noise ratio (CNR) and effective dose efficiency (eDE) were used as physical image quality metrics measured in a uniform chest phantom. Although optimal values of these physical metrics for chest radiography were not derived in this work, their correlation with VGAS in images acquired without an antiscatter grid across the diagnostic range of X-ray tube voltages was determined using Pearson's correlation coefficient. Clinical and physical image quality metrics increased with decreasing tube voltage. Statistically significant correlations between VGAS and CNR (R=0.87, p<0.033) and eDE (R=0.77, p<0.008) were observed. Medical physics experts may use the physical image quality metrics described here in quality assurance programmes and optimisation studies with a degree of confidence that they reflect the clinical image quality in chest CR images acquired without an antiscatter grid. A statistically significant correlation has been found between the clinical and physical image quality in CR chest imaging. The results support the value of using CNR and eDE in the evaluation of quality in clinical thorax radiography.

Correlation of the clinical and physical image quality in chest radiography for average adults with a computed radiography imaging system

PubMed Central

Wood, T J; Beavis, A W; Saunderson, J R

2013-01-01

Objective: The purpose of this study was to examine the correlation between the quality of visually graded patient (clinical) chest images and a quantitative assessment of chest phantom (physical) images acquired with a computed radiography (CR) imaging system. Methods: The results of a previously published study, in which four experienced image evaluators graded computer-simulated postero-anterior chest images using a visual grading analysis scoring (VGAS) scheme, were used for the clinical image quality measurement. Contrast-to-noise ratio (CNR) and effective dose efficiency (eDE) were used as physical image quality metrics measured in a uniform chest phantom. Although optimal values of these physical metrics for chest radiography were not derived in this work, their correlation with VGAS in images acquired without an antiscatter grid across the diagnostic range of X-ray tube voltages was determined using Pearson’s correlation coefficient. Results: Clinical and physical image quality metrics increased with decreasing tube voltage. Statistically significant correlations between VGAS and CNR (R=0.87, p<0.033) and eDE (R=0.77, p<0.008) were observed. Conclusion: Medical physics experts may use the physical image quality metrics described here in quality assurance programmes and optimisation studies with a degree of confidence that they reflect the clinical image quality in chest CR images acquired without an antiscatter grid. Advances in knowledge: A statistically significant correlation has been found between the clinical and physical image quality in CR chest imaging. The results support the value of using CNR and eDE in the evaluation of quality in clinical thorax radiography. PMID:23568362

Clinical evaluation of a mobile digital specimen radiography system for intraoperative specimen verification.

PubMed

Wang, Yingbing; Ebuoma, Lilian; Saksena, Mansi; Liu, Bob; Specht, Michelle; Rafferty, Elizabeth

2014-08-01

Use of mobile digital specimen radiography systems expedites intraoperative verification of excised breast specimens. The purpose of this study was to evaluate the performance of a such a system for verifying targets. A retrospective review included 100 consecutive pairs of breast specimen radiographs. Specimens were imaged in the operating room with a mobile digital specimen radiography system and then with a conventional digital mammography system in the radiology department. Two expert reviewers independently scored each image for image quality on a 3-point scale and confidence in target visualization on a 5-point scale. A target was considered confidently verified only if both reviewers declared the target to be confidently detected. The 100 specimens contained a total of 174 targets, including 85 clips (49%), 53 calcifications (30%), 35 masses (20%), and one architectural distortion (1%). Although a significantly higher percentage of mobile digital specimen radiographs were considered poor quality by at least one reviewer (25%) compared with conventional digital mammograms (1%), 169 targets (97%), were confidently verified with mobile specimen radiography; 172 targets (98%) were verified with conventional digital mammography. Three faint masses were not confidently verified with mobile specimen radiography, and conventional digital mammography was needed for confirmation. One faint mass and one architectural distortion were not confidently verified with either method. Mobile digital specimen radiography allows high diagnostic confidence for verification of target excision in breast specimens across target types, despite lower image quality. Substituting this modality for conventional digital mammography can eliminate delays associated with specimen transport, potentially decreasing surgical duration and increasing operating room throughput.

A maximum likelihood method for high resolution proton radiography/proton CT.

PubMed

Collins-Fekete, Charles-Antoine; Brousmiche, Sébastien; Portillo, Stephen K N; Beaulieu, Luc; Seco, Joao

2016-12-07

Multiple Coulomb scattering (MCS) is the largest contributor to blurring in proton imaging. In this work, we developed a maximum likelihood least squares estimator that improves proton radiography's spatial resolution. The water equivalent thickness (WET) through projections defined from the source to the detector pixels were estimated such that they maximizes the likelihood of the energy loss of every proton crossing the volume. The length spent in each projection was calculated through the optimized cubic spline path estimate. The proton radiographies were produced using Geant4 simulations. Three phantoms were studied here: a slanted cube in a tank of water to measure 2D spatial resolution, a voxelized head phantom for clinical performance evaluation as well as a parametric Catphan phantom (CTP528) for 3D spatial resolution. Two proton beam configurations were used: a parallel and a conical beam. Proton beams of 200 and 330 MeV were simulated to acquire the radiography. Spatial resolution is increased from 2.44 lp cm -1 to 4.53 lp cm -1 in the 200 MeV beam and from 3.49 lp cm -1 to 5.76 lp cm -1 in the 330 MeV beam. Beam configurations do not affect the reconstructed spatial resolution as investigated between a radiography acquired with the parallel (3.49 lp cm -1 to 5.76 lp cm -1 ) or conical beam (from 3.49 lp cm -1 to 5.56 lp cm -1 ). The improved images were then used as input in a photon tomography algorithm. The proton CT reconstruction of the Catphan phantom shows high spatial resolution (from 2.79 to 5.55 lp cm -1 for the parallel beam and from 3.03 to 5.15 lp cm -1 for the conical beam) and the reconstruction of the head phantom, although qualitative, shows high contrast in the gradient region. The proposed formulation of the optimization demonstrates serious potential to increase the spatial resolution (up by 65[Formula: see text]) in proton radiography and greatly accelerate proton computed tomography reconstruction.

Optimization of exposure factors for X-ray radiography non-destructive testing of pearl oyster

NASA Astrophysics Data System (ADS)

Susilo; Yulianti, I.; Addawiyah, A.; Setiawan, R.

2018-03-01

One of the processes in pearl oyster cultivation is detecting the pearl nucleus to gain information whether the pearl nucleus is still attached in the shell or vomited. The common tool used to detect pearl nucleus is an X-ray machine. However, an X-ray machine has a drawback that is the energy used is higher than that used by digital radiography. The high energy make the resulted image is difficult to be analysed. One of the advantages of digital radiography is the energy used can be adjusted so that the resulted image can be analysed easily. To obtain a high quality of pearl image using digital radiography, the exposure factors should be optimized. In this work, optimization was done by varying the voltage, current, and exposure time. Then, the radiography images were analysed using Contrast to Noise Ratio (CNR). From the analysis, it can be determined that the optimum exposure factors are 60 kV of voltage, 16 mA of current, and 0.125 s of exposure time which result in CNR of 5.71.

Technique and interpretation in tree seed radiography

Treesearch

Howard B. Kriebel

1966-01-01

The study of internal seed structure by radiography requires techniques which will give good definition. To establish the best procedures, we conducted a series of experiments in which we manipulated the principal controllable variables affecting the quality of X-radiographs: namely, focus-to-film distance, film speed (grain), exposure time, kilovoltage, and...

Action research in radiography: What it is and how it can be conducted

PubMed Central

Munn, Zachary; Pearson, Alan; Jordan, Zoe; Murphy, Frederick; Pilkington, Diana

2013-01-01

Action research is a form of research that investigates and describes a social or work situation with the aim of achieving a change which results in improvement. This article emphasizes the potential for action research to be a useful research method in radiography. A search was conducted to determine the extent to which action research has been utilized in radiography. Although action research has been used in a number of health-care settings, there are no published examples of action research being utilized in a clinical medical imaging department. Action research is discussed in detail, along with an example guide for an action research study. Action research has been identified as a useful way to affect change, to involve radiographers in the research process, and to introduce evidence-based practice to radiography. PMID:26229607

Problem-based learning for radiological technologists: a comparison of student attitudes toward plain radiography.

PubMed

Terashita, Takayoshi; Tamura, Naomi; Kisa, Kengo; Kawabata, Hidenobu; Ogasawara, Katsuhiko

2016-09-05

Knowledge and skill expected of healthcare providers continues to increase alongside developments in medicine and healthcare. Problem-based learning (PBL) is therefore increasingly necessary in training courses for radiological technologists. However, it is necessary to evaluate the effects of PBL to completely introduce it in our education programs. As a Hypothesis, it seems that a change occurs in the student's attitudes by participating in PBL practical training. There is the Semantic Differential (SeD) technique as a method to identify student's attitudes. We conceived that PBL could be appropriately evaluated by using SeD technique. In this paper, we evaluated PBL for plain radiography practical training using the SeD technique. Thirty-eight third-year students studying radiological technology participated. PBL was introduced to practical training in plain radiography positioning techniques. Five sessions lasting 5 h each were delivered over a 5-week period during November to December 2012. The clinical scenario was an emergency case with multiple trauma requiring plain radiography. Groups comprising approximately eight students created workflows for trauma radiography with consideration of diagnostic accuracy and patient safety. Furthermore, students groups conducted plain radiography on a patient phantom according to created workflows and were then guided by feedback from professional radiologists. All students answered SeD questionnaires to assess views on plain radiography before instruction to provide preliminary practical training reports and after completing practical training. The factors were identified using factor analysis of the questionnaires, which were answered before and after each practical training session. On evaluation of the relationships between factors and question items according to factor loading, we identified "reluctance", "confidence", and "exhaustion" as the predominant attitudes before practical training. Similarly, we identified

Method and Apparatus for Computed Imaging Backscatter Radiography

NASA Technical Reports Server (NTRS)

Shedlock, Daniel (Inventor); Sabri, Nissia (Inventor); Dugan, Edward T. (Inventor); Jacobs, Alan M. (Inventor); Meng, Christopher (Inventor)

2013-01-01

Systems and methods of x-ray backscatter radiography are provided. A single-sided, non-destructive imaging technique utilizing x-ray radiation to image subsurface features is disclosed, capable of scanning a region using a fan beam aperture and gathering data using rotational motion.

Enhancement of digital radiography image quality using a convolutional neural network.

PubMed

Sun, Yuewen; Li, Litao; Cong, Peng; Wang, Zhentao; Guo, Xiaojing

2017-01-01

Digital radiography system is widely used for noninvasive security check and medical imaging examination. However, the system has a limitation of lower image quality in spatial resolution and signal to noise ratio. In this study, we explored whether the image quality acquired by the digital radiography system can be improved with a modified convolutional neural network to generate high-resolution images with reduced noise from the original low-quality images. The experiment evaluated on a test dataset, which contains 5 X-ray images, showed that the proposed method outperformed the traditional methods (i.e., bicubic interpolation and 3D block-matching approach) as measured by peak signal to noise ratio (PSNR) about 1.3 dB while kept highly efficient processing time within one second. Experimental results demonstrated that a residual to residual (RTR) convolutional neural network remarkably improved the image quality of object structural details by increasing the image resolution and reducing image noise. Thus, this study indicated that applying this RTR convolutional neural network system was useful to improve image quality acquired by the digital radiography system.

The New Facilities for Neutron Radiography at the LVR-15 Reactor

NASA Astrophysics Data System (ADS)

Soltes, J.; Viererbl, L.; Vacik, J.; Tomandl, I.; Krejci, F.; Jakubek, J.

2016-09-01

Neutron radiography is an imaging method often used at research reactor sites. Back in 2011 a project was started with the goal to build a neutron radiography facility at the site of the LVR-15 research reactor in Rez, Czech Republic. In the scope of the project two horizontal channels were adapted for the needs of neutron radiography. This comprises the HC1 channel which offers an intense thermal neutron beam with a diameter of 10 cm, which can be used for imaging of larger samples, and the HC3 channel which beam is restricted just to 4x80 mm2, but is highly thermalized, collimated and reduced from gamma background, thus capable of providing better radiograph resolution. Both facilities are equipped with newest Timepix based detectors, with thin 6LiF converters for neutron detection capable of delivering high resolution. Both facilities offer a unique opportunity for non-destructive testing in the Czech region. In 2015 both facilities were put into test operation and several radiographs were acquired, which are presented in the following text.

Detection of gastritis by single- and double-contrast radiography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thoeni, R.F.; Goldberg, H.I.; Ominsky, S.

1983-09-01

Sixty-eight patients with various types of gastritis, 23 patients with normal stomachs, and four patients with other gastric diseases were examined in a prospective study to assess the sensitivity and specificity of single-contrast (SC) and double-contrast (DC) upper gastrointestinal examinations in the evaluation of gastritis. All patients underwent endoscopy with biopsy followed first by DC and then by SC radiography. The respective sensitivities of SC and DC radiography were 58% and 72% for all examinations and 59% and 77% for adequate examinations only. The respective specificities were 59% and 55% based on all examinations. Useful radiographic features included polypoid defectsmore » and erosions detected by both methods, abnormal folds and flattened margins detected by the SC technique, and narrowed lumen and crenulated margins detected by the DC technique. In 93% of all cases, the correct diagnosis was based on two or more of these radiographic features. According to this study, the radiographic sensitivity in the detection of gastritis is reliable only in cases of moderate-to-severe disease and only when based on findings of the DC examination. Neither SC nor DC radiography should be used as the primary screening method for patients with suspected gastritis, and the radiographic diagnosis should be restricted to the terms ''erosive'' or ''nonerosive gastritis.''« less

The phrenic nerve with accompanying vessels: a silent cause of cardiovascular border obliteration on chest radiography.

PubMed

Farhana, Shiri; Ashizawa, Kazuto; Hayashi, Hideyuki; Ogihara, Yukihiro; Aso, Nobuya; Hayashi, Kuniaki; Uetani, Masataka

2015-12-01

Our aim was to clarify the frequency of cardiovascular border obliteration on frontal chest radiography and to prove that the phrenic nerve with accompanying vessels can be considered as a cause of obliteration of cardiovascular border on an otherwise normal chest radiography. Two radiologists reviewed chest radiographs and computed tomography (CT) images of 100 individuals. CT confirmed the absence of intrapulmonary or extrapulmonary abnormalities in all of them. We examined the frequency of cardiovascular border obliteration on frontal chest radiography and summarized the causes of obliteration as pericardial fat pad, phrenic nerve, intrafissure fat, pulmonary vessels, and others, comparing them with CT in each case. Cardiovascular border was obliterated on frontal chest radiography in 46 cases on the right and in 61 on the left. The phrenic nerve with accompanying vessels was found to be a cause of obliteration in 34 of 46 cases (74%) on the right and 29 of 61 (48%) cases on the left. The phrenic nerve was the most frequent cause of cardiovascular border obliteration on both sides. The phrenic nerve with accompanying vessels, forming a prominent fold of parietal pleura, can be attributed as a cause of cardiovascular border obliteration on frontal chest radiography.

[TUBERCULOSIS SCREENING BY CHEST RADIOGRAPHY AMONG INTERNATIONAL STUDENTS AT JAPANESE LANGUAGE SCHOOLS IN OSAKA CITY].

PubMed

Tsuda, Yuko; Matsumoto, Kenji; Komukai, Jun; Furukawa, Kanae; Saito, Kazumi; Shimouchi, Akira

2015-10-01

With a broader aim of controlling pulmonary tuberculosis (TB) among foreigners, here, we have reported the findings of chest radiography screening for TB among international students at Japanese language schools in Osaka city. Between April 2011 and December 2013, 4,529 international students from 19 Japanese language schools in Osaka city underwent chest radiography for TB screening. The chest radiographs were studied in reference to the student's sex, age, nationality, and date of entry to Japan as well as any health conditions present at the time of screening. We further analyzed the bacterial information and pulmonary TB classification based on chest radiography findings of students who were identified to be positive for TB. Information on the implementation of health education was also gathered. The results revealed that 52.5% of the students who underwent chest radiography came from China, 20.3 % from South Korea, and 16.3% from Vietnam. Of the students, 52.9% were male and 47.1% were female. The median age of students was 23 years (range: 14-70 years). The median number of days from the first date of entry to Japan up until the radiography screening was 63 days. Based on the chest radiography findings, 71 students (1.6%) were suspected to have TB; however, further detailed examination confirmed that 19 students (0.4%) had active TB. This percentage is significantly higher than the 0.1% TB identification rate among residents in Osaka city of the same time period (P<0.001), which was also determined by chest radiography. The median age of the 19 TB positive patients was 23 years. Among them, 14 (73.7%) were male. The median time from the date of entry to Japan to the date of the chest radiography screening was 137 days. For 16 of those students, the entry to Japan was within 1 year of the radiography. Of the 19 TB positive patients, 16 (84.2%) did not have respiratory symptoms, 15 (79.0%) had sputum smear negative results, and 17 (89.5%) had no cavity. Health

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

PubMed Central

NAGAMINE, Kanetada

2016-01-01

Cosmic-ray muons (CRM) arriving from the sky on the surface of the earth are now known to be used as radiography purposes to explore the inner-structure of large-scale objects and landforms, ranging in thickness from meter to kilometers scale, such as volcanic mountains, blast furnaces, nuclear reactors etc. At the same time, by using muons produced by compact accelerators (CAM), advanced radiography can be realized for objects with a thickness in the sub-millimeter to meter range, with additional exploration capability such as element identification and bio-chemical analysis. In the present report, principles, methods and specific research examples of CRM transmission radiography are summarized after which, principles, methods and perspective views of the future CAM radiography are described. PMID:27725469

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

PubMed

Nagamine, Kanetada

2016-01-01

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

Spectroscopic neutron radiography for a cargo scanning system

NASA Astrophysics Data System (ADS)

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

2016-06-01

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

Comparison of three-view thoracic radiography and computed tomography for detection of pulmonary nodules in dogs with neoplasia.

PubMed

Armbrust, Laura J; Biller, David S; Bamford, Aubrey; Chun, Ruthanne; Garrett, Laura D; Sanderson, Michael W

2012-05-01

To compare the detection of pulmonary nodules by use of 3-view thoracic radiography and CT in dogs with confirmed neoplasia. Prospective case series. 33 dogs of various breeds. 3 interpreters independently evaluated 3-view thoracic radiography images. The location and size of pulmonary nodules were recorded. Computed tomographic scans of the thorax were obtained and evaluated by a single interpreter. The location, size, margin, internal architecture, and density of pulmonary nodules were recorded. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for thoracic radiography (with CT as the gold standard). 21 of 33 (64%) dogs had pulmonary nodules or masses detected on CT. Of the dogs that had positive CT findings, 17 of 21 (81%) had pulmonary nodules or masses detected on radiographs by at least 1 interpreter. Sensitivity of radiography ranged from 71% to 95%, and specificity ranged from 67% to 92%. Radiography had a positive predictive value of 83% to 94% and a negative predictive value of 65% to 89%. The 4 dogs that were negative for nodules on thoracic radiography but positive on CT were all large-breed to giant-breed dogs with osteosarcoma. CT was more sensitive than radiography for detection of pulmonary nodules. This was particularly evident in large-breed to giant-breed dogs. Thoracic CT is recommended in large-breed to giant-breed dogs with osteosarcoma if the detection of pulmonary nodules will change treatment.

Comparison of scatter rejection and low-contrast performance of scan equalization digital radiography (SEDR), slot-scan digital radiography, and full-field digital radiography systems for chest phantom imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu Xinming; Shaw, Chris C.; Lai, Chao-Jen

Purpose: To investigate and compare the scatter rejection properties and low-contrast performance of the scan equalization digital radiography (SEDR) technique to the slot-scan and conventional full-field digital radiography techniques for chest imaging. Methods: A prototype SEDR system was designed and constructed with an a-Se flat-panel (FP) detector to improve image quality in heavily attenuating regions of an anthropomorphic chest phantom. Slot-scanning geometry was used to reject scattered radiation without attenuating primary x rays. The readout scheme of the FP was modified to erase accumulated scatter signals prior to image readout. A 24-segment beam width modulator was developed to regulate x-raymore » exposures regionally and compensate for the low x-ray flux in heavily attenuating regions. To measure the scatter-to-primary ratios (SPRs), a 2 mm thick lead plate with a 2-D array of aperture holes was used to measure the primary signals, which were then subtracted from those obtained without the lead plate to determine scatter components. A 2-D array of aluminum beads (3 mm in diameter) was used as the low-contrast objects to measure the contrast ratios (CRs) and contrast-to-noise ratios (CNRs) for evaluating the low-contrast performance in chest phantom images. A set of two images acquired with the same techniques were subtracted from each other to measure the noise levels. SPRs, CRs, and CNRs of the SEDR images were measured in four anatomical regions of chest phantom images and compared to those of slot-scan images and full-field images acquired with and without antiscatter grid. Results: The percentage reduction of SPR (percentage of SPRs reduced with scatter removal/rejection methods relative to that for nongrid full-field imaging) averaged over four anatomical regions was measured to be 80%, 83%, and 71% for SEDR, slot-scan, and full-field with grid, respectively. The average CR over four regions was found to improve over that for nongrid full

Mobile radiography at a music festival.

PubMed

Walker, A; Brenchley, J; Hughes, N

2009-08-01

Limb injuries are common at music festival sites and traditionally patients seen by on-site medical services require referral to hospital emergency departments for radiographic exclusion of bony injury. This takes clinical personnel off site, increases demand on local emergency departments and is inconvenient for revellers. This is an audit of the use of a portable digital radiography system at the Virgin music festival in Staffordshire over a 3-year period.

Chest radiography practice in critically ill patients: a postal survey in the Netherlands

PubMed Central

Graat, Marleen E; Hendrikse, Karin A; Spronk, Peter E; Korevaar, Johanna C; Stoker, Jaap; Schultz, Marcus J

2006-01-01

Background To ascertain current chest radiography practice in intensive care units (ICUs) in the Netherlands. Methods Postal survey: a questionnaire was sent to all ICUs with > 5 beds suitable for mechanical ventilation; pediatric ICUs were excluded. When an ICU performed daily-routine chest radiographs in any group of patients it was considered to be a "daily-routine chest radiography" ICU. Results From the number of ICUs responding, 63% practice a daily-routine strategy, in which chest radiographs are obtained on a daily basis without any specific reason. A daily-routine chest radiography strategy is practiced less frequently in university-affiliated ICUs (50%) as compared to other ICUs (68%), as well as in larger ICUs (> 20 beds, 50%) as compared to smaller ICUs (< 20 beds, 65%) (P > 0.05). Remarkably, physicians that practice a daily-routine strategy consider daily-routine radiographs helpful in guiding daily practice in less than 30% of all performed radiographs. Chest radiographs are considered essential for verification of the position of invasive devices (81%) and for diagnosing pneumothorax, pneumonia or acute respiratory distress syndrome (82%, 74% and 69%, respectively). On demand chest radiographs are obtained after introduction of thoracic drains, central venous lines and endotracheal tubes in 98%, 84% and 75% of responding ICUs, respectively. Chest films are also obtained in case of ventilatory deterioration (49% of responding ICUs), and after cardiopulmonary resuscitation (59%), tracheotomy (58%) and mini-tracheotomy (23%). Conclusion There is notable lack of consensus on chest radiography practice in the Netherlands. This survey suggests that a large number of intensivists may doubt the value of daily-routine chest radiography, but still practice a daily-routine strategy. PMID:16848892

The evaluation the magnitude radiation exposure dose rate in digital radiography room design

NASA Astrophysics Data System (ADS)

Dwiyanto, Agung; Setia Budi, Wahyu; Hardiman, Gagoek

2017-12-01

This study discusses the dose rate in digital radiography room, buit according to meet the provisions of KEMENKES No.1014 / Menkes / SK / XI / 2008 and Regulation of BAPETEN No. 8 / 2011. The provisions primary concern of radiation safety, not comfort, by considering the space design. There are five aspects to consider in designing the space: functionality, comfort, security, movement activities and aesthetics. However provisions only met three aspects of the design, which are a function, security and movement activity. Therefore, it is necessary to evaluate digital radiography room in terms of its ability to control external radiation exposure to be safe and comfortable The dose rate is measured by the range of primary and secondary radiation in the observation points by using Surveymeter. All data are obtained by the preliminary survey prior to the study. Furthermore, the review of digital radiography room is done based on architectural design theory. The dose rate for recommended improvement room is recalculated using the same method as the actual room with the help of computer modeling. The result of dose rate calculation at the inner and outer part of digital radiography observation room shows that in-room dose for a week at each measuring point exceeds the allowable dose limit both for staff and public. During a week of observation, the outdoor dose at some measuring points exceeds the dose limit set by the KEMENKES No.1014 / Menkes / SK / XI / 2008 and Regulation BEPETEN No 8/2011. Meanwhile, the result of dose rate calculation in the inner and outer part of the improved digital radiography room can meet the applicable regulations better.

X-ray backscatter imaging for radiography by selective detection and snapshot: Evolution, development, and optimization

NASA Astrophysics Data System (ADS)

Shedlock, Daniel

Compton backscatter imaging (CBI) is a single-sided imaging technique that uses the penetrating power of radiation and unique interaction properties of radiation with matter to image subsurface features. CBI has a variety of applications that include non-destructive interrogation, medical imaging, security and military applications. Radiography by selective detection (RSD), lateral migration radiography (LMR) and shadow aperture backscatter radiography (SABR) are different CBI techniques that are being optimized and developed. Radiography by selective detection (RSD) is a pencil beam Compton backscatter imaging technique that falls between highly collimated and uncollimated techniques. Radiography by selective detection uses a combination of single- and multiple-scatter photons from a projected area below a collimation plane to generate an image. As a result, the image has a combination of first- and multiple-scatter components. RSD techniques offer greater subsurface resolution than uncollimated techniques, at speeds at least an order of magnitude faster than highly collimated techniques. RSD scanning systems have evolved from a prototype into near market-ready scanning devices for use in a variety of single-sided imaging applications. The design has changed to incorporate state-of-the-art detectors and electronics optimized for backscatter imaging with an emphasis on versatility, efficiency and speed. The RSD system has become more stable, about 4 times faster, and 60% lighter while maintaining or improving image quality and contrast over the past 3 years. A new snapshot backscatter radiography (SBR) CBI technique, shadow aperture backscatter radiography (SABR), has been developed from concept and proof-of-principle to a functional laboratory prototype. SABR radiography uses digital detection media and shaded aperture configurations to generate near-surface Compton backscatter images without scanning, similar to how transmission radiographs are taken. Finally, a

42 CFR 37.42 - Chest radiograph specifications-digital radiography systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... resolution, modulation transfer function (MTF), image signal-to-noise and detective quantum efficiency must... Information Object Definitions, sections: Computed Radiography Image Information Object Definition; Digital X...

Comparing posteroanterior with lateral and anteroposterior chest radiography in the initial detection of parapneumonic effusions.

PubMed

Moffett, Bryan K; Panchabhai, Tanmay S; Nakamatsu, Raul; Arnold, Forest W; Peyrani, Paula; Wiemken, Timothy; Guardiola, Juan; Ramirez, Julio A

2016-12-01

It is unclear whether anteroposterior (AP) or posteroanterior with lateral (PA/Lat) chest radiographs are superior in the early detection of clinically relevant parapneumonic effusions (CR-PPEs). The objective of this study was to identify which technique is preferred for detection of PPEs using chest computed tomography (CCT) as a reference standard. A secondary analysis of a pneumonia database was conducted to identify patients who received a CCT within 24 hours of presentation and also received AP or PA/Lat chest radiographs within 24 hours of CCT. Sensitivity and specificity were then calculated by comparing the radiographic diagnosis of PPEs of both types of radiographs compared with CCT by using the existing attending radiologist interpretation. Clinical relevance of effusions was determined by CCT effusion measurement of >2.5 cm or presence of loculation. There was a statistically significant difference between the sensitivity of AP (67.3%) and PA/Lat (83.9%) chest radiography for the initial detection of CR-PPE. Of 16 CR-PPEs initially missed by AP radiography, 7 either required drainage initially or developed empyema within 30 days, whereas no complicated PPE or empyema was found in those missed by PA/Lat radiography. PA/Lat chest radiography should be the initial imaging of choice in pneumonia patients for detection of PPEs because it appears to be statistically superior to AP chest radiography. Published by Elsevier Inc.

The sensitivity of radiography of the postoperative stomach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ott, D.J.; Munitz, H.A.; Gelfand, D.W.

1982-09-01

The results of radiology and endoscopy were compared in 140 patients who had undergone gastric surgery for ulcer disease. Of 74 patients who were examined with single-contrast radiography, 37 had abnormalities that were demonstrated endoscopically. The radiographic sensitivities in these patients were: gastritis 2/22 (9%); ulcer 3/5 (60%); obstruction 8/8 (100%); and miscellaneous abnormalities 2/2 (100%). The predictive accuracy of a diagnois of ulcer was 38%. Of the 66 patients who were examined with double-contrast radiography, 33 abnormalities were found with endoscopy. The radiographic sensitivities were: gastritis 3/13 (23%); ulcer 7/10 (70%); obstruction 4/4 (100%); and miscellaneous abnormalities 6/6 (100%).more » The predictive accuracy of a diagnosis of ulcer was 44%. Radiology appears to be unreliable in diagnosing gastritis and recurrent ulceration in the post-operation stomach. The double-contrast technique does not offer significant improvement over the single-contrast method in evaluating these postoperative problems.« less

Comparison of the accuracy of radiography and ultrasonography for detection of articular lesions in horses.

PubMed

Hinz, Antje; Fischer, Andrew T

2011-10-01

To compare the accuracy of ultrasonographic and radiographic examination for evaluation of articular lesions in horses. Cross-sectional study. Horses (n = 137) with articular lesions. Radiographic and ultrasonographic examinations of the affected joint(s) were performed before diagnostic or therapeutic arthroscopic surgery. Findings were recorded and compared to lesions identified during arthroscopy. In 254 joints, 432 lesions were identified by arthroscopy. The overall accuracy was 82.9% for ultrasonography and 62.2% for radiography (P < .0001) with a sensitivity of 91.4% for ultrasonography and 66.7% for radiography (P < .0001). The difference in specificity was not statistically significant (P = .2628). The negative predictive value for ultrasonography was 31.5% and 13.2% for radiography (P = .0022), the difference for the positive predictive value was not statistically significant (P = .3898). The accuracy for ultrasonography and radiography for left versus right joints was equal and corresponded with the overall results. Ultrasonographic evaluation of articular lesions was more accurate than radiographic evaluation. © Copyright 2011 by The American College of Veterinary Surgeons.

Evaluation of exposure parameters in plain radiography: a comparative study with European guidelines.

PubMed

Lança, L; Silva, A; Alves, E; Serranheira, F; Correia, M

2008-01-01

Typical distribution of exposure parameters in plain radiography is unknown in Portugal. This study aims to identify exposure parameters that are being used in plain radiography in the Lisbon area and to compare the collected data with European references [Commission of European Communities (CEC) guidelines]. The results show that in four examinations (skull, chest, lumbar spine and pelvis), there is a strong tendency of using exposure times above the European recommendation. The X-ray tube potential values (in kV) are below the recommended values from CEC guidelines. This study shows that at a local level (Lisbon region), radiographic practice does not comply with CEC guidelines concerning exposure techniques. Further national/local studies are recommended with the objective to improve exposure optimisation and technical procedures in plain radiography. This study also suggests the need to establish national/local diagnostic reference levels and to proceed to effective measurements for exposure optimisation.

The “dirty chest”—correlations between chest radiography, multislice CT and tobacco burden

PubMed Central

Kirchner, J; Goltz, J P; Lorenz, F; Obermann, A; Kirchner, E M; Kickuth, R

2012-01-01

Objectives Cigarette smoking-induced airway disease commonly results in an overall increase of non-specific lung markings on chest radiography. This has been described as “dirty chest”. As the morphological substrate of this condition is similar to the anthracosilicosis of coal workers, we hypothesised that it is possible to quantify the radiological changes using the International Labour Organization (ILO) classification of pneumoconiosis. The aims of this study were to evaluate whether there is a correlation between the extent of cigarette smoking and increased lung markings on chest radiography and to correlate the chest radiographic scores with findings on CT studies. Methods In a prospective analysis a cohort of 85 smokers was examined. The cigarette consumption was evaluated in pack years (defined as 20 cigarettes per day over 1 year). Film reading was performed by two board-certified radiologists. Chest radiographs were evaluated for the presence of thickening of bronchial walls, the presence of linear or nodular opacities, and emphysema. To correlate the smoking habits with the increase of overall lung markings in chest radiography, the ILO profusion score was converted to numbers ranging from zero to nine. Chest radiographs were rated according to the complete set of standard films of the revised ILO classification. Results 63/85 (74%) of the smokers showed an increase in overall lung markings on chest radiography; 32 (37%) had an ILO profusion score of <1/1, 29 (34%) had an ILO profusion score of <2/2 and 2 (2%) had an ILO score of ≥2/2. There was a significant positive linear correlation between the increase of overall lung markings on chest radiography and the cigarette consumption quantified as pack years (r=0.68). The majority of the heavy smokers (>40 pack years) showed emphysema; there was no significant difference between the prevalence of emphysema as diagnosed by CT (62%) or chest radiography (71%) (p<0.05).The most common findings in CT

Neutron Radiography of Fluid Flow for Geothermal Energy Research

NASA Astrophysics Data System (ADS)

Bingham, P.; Polsky, Y.; Anovitz, L.; Carmichael, J.; Bilheux, H.; Jacobsen, D.; Hussey, D.

Enhanced geothermal systems seek to expand the potential for geothermal energy by engineering heat exchange systems within the earth. A neutron radiography imaging method has been developed for the study of fluid flow through rock under environmental conditions found in enhanced geothermal energy systems. For this method, a pressure vessel suitable for neutron radiography was designed and fabricated, modifications to imaging instrument setups were tested, multiple contrast agents were tested, and algorithms developed for tracking of flow. The method has shown success for tracking of single phase flow through a manufactured crack in a 3.81 cm (1.5 inch) diameter core within a pressure vessel capable of confinement up to 69 MPa (10,000 psi) using a particle tracking approach with bubbles of fluorocarbon-based fluid as the ;particles; and imaging with 10 ms exposures.

Relationship Between the Number of Clinical Sites in Radiography Programs and Job Placement Rates of Graduates.

PubMed

Harrell, Angela; Matthews, Eric

2016-07-01

To determine whether a relationship exists between the number of clinical sites available in radiography programs accredited by the Joint Review Committee on Education in Radiologic Technology and the job placement rates of graduates. We performed a secondary analysis of data on job placement rates and the number of clinical sites available in 438 degree-granting radiography programs from January 2015 to March 2015. A weak, negative, nonsignificant correlation existed between the number of clinical sites and the job placement rate (Spearman's rho = -.113, n = 438, P = .018). The coefficient of determination was 1.28%.Discussion Research evaluating factors contributing to graduate employability is limited but indicates no need for radiography program administrators to adjust clinical site numbers solely on the basis of improving graduate employability. The number of clinical sites available in a radiography program is not related to the job placement rate of its graduates. ©2016 American Society of Radiologic Technologists.

200 MeV Proton Radiography Studies with a Hand Phantom Using a Prototype Proton CT Scanner

PubMed Central

Plautz, Tia; Bashkirov, V.; Feng, V.; Hurley, F.; Johnson, R.P.; Leary, C.; Macafee, S.; Plumb, A.; Rykalin, V.; Sadrozinski, H.F.-W.; Schubert, K.; Schulte, R.; Schultze, B.; Steinberg, D.; Witt, M.; Zatserklyaniy, A.

2014-01-01

Proton radiography has applications in patient alignment and verification procedures for proton beam radiation therapy. In this paper, we report an experiment which used 200 MeV protons to generate proton energy-loss and scattering radiographs of a hand phantom. The experiment used the first-generation proton CT scanner prototype, which was installed on the research beam line of the clinical proton synchrotron at Loma Linda University Medical Center (LLUMC). It was found that while both radiographs displayed anatomical details of the hand phantom, the energy-loss radiograph had a noticeably higher resolution. Nonetheless, scattering radiography may yield more contrast between soft and bone tissue than energy-loss radiography, however, this requires further study. This study contributes to the optimization of the performance of the next-generation of clinical proton CT scanners. Furthermore, it demonstrates the potential of proton imaging (proton radiography and CT), which is now within reach of becoming available as a new, potentially low-dose medical imaging modality. PMID:24710156

X-ray absorption radiography for high pressure shock wave studies

NASA Astrophysics Data System (ADS)

Antonelli, L.; Atzeni, S.; Batani, D.; Baton, S. D.; Brambrink, E.; Forestier-Colleoni, P.; Koenig, M.; Le Bel, E.; Maheut, Y.; Nguyen-Bui, T.; Richetta, M.; Rousseaux, C.; Ribeyre, X.; Schiavi, A.; Trela, J.

2018-01-01

The study of laser compressed matter, both warm dense matter (WDM) and hot dense matter (HDM), is relevant to several research areas, including materials science, astrophysics, inertial confinement fusion. X-ray absorption radiography is a unique tool to diagnose compressed WDM and HDM. The application of radiography to shock-wave studies is presented and discussed. In addition to the standard Abel inversion to recover a density map from a transmission map, a procedure has been developed to generate synthetic radiographs using density maps produced by the hydrodynamics code DUED. This procedure takes into account both source-target geometry and source size (which plays a non negligible role in the interpretation of the data), and allows to reproduce transmission data with a good degree of accuracy.

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

PubMed

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

2013-07-01

Porous asphalt as a road surface layer controls aquaplaning as rain water can drain through its highly porous structure. The process of water drainage through this permeable layer is studied using neutron radiography. Time-resolved water configuration and distribution within the porous structure are reported. It is shown that radiography depicts the process of liquid water transport within the complex geometry of porous asphalt, capturing water films, filled dead end pores and water islands. Copyright © 2013 Elsevier Ltd. All rights reserved.

Does transitioning from computed radiography (CR) to direct radiography (DR) with portable imaging systems affect workflow efficiency?

NASA Astrophysics Data System (ADS)

Gali, Raja L.; Roth, Christopher G.; Smith, Elizabeth; Dave, Jaydev K.

2018-03-01

In digital radiography, computed radiography (CR) technology is based on latent image capture by storage phosphors whereas direct radiography (DR) technology is based either on indirect conversion using a scintillator or direct conversion using a photoconductor. DR-based portable imaging systems may enhance workflow efficiency. The purpose of this work was to investigate changes in workflow efficiency at a tertiary healthcare center after transitioning from CR to DR technology for imaging with portable x-ray units. An IRB exemption was obtained. Data for all inpatient-radiographs acquired with portable x-ray units from July-2014 till June-2015 (period 1) with CR technology (AMX4 or AMX4+ portable unit from GE Healthcare, NX workstation from Agfa Healthcare for digitization), from July-2015 till June-2016 (period 2) with DR technology (Carestream DRX-Revolution x-ray units and DRX-1C image receptors) and from July-2016 till January-2017 (period 3; same DR technology) were extracted using Centricity RIS-IC (GE Healthcare). Duration between the imaging-examination scheduled time and completed time (timesch-com) was calculated and compared using non-parametric tests (between the three time periods with corrections for multiple comparisons; three time periods were used to identify if there were any other potential temporal trends not related to transitioning from CR to DR). IBM's SPSS package was used for statistical analysis. Overall data was obtained from 33131, 32194, and 18015 cases in periods 1, 2 and 3, respectively. Independent-Samples Kruskal-Wallis test revealed a statistically significant difference in timesch-com across the three time periods (χ2(2, n= 83,340) = 2053, p < 0.001). The timesch-com was highest for period 1 i.e., radiographs acquired with CR technology (median: 64 minutes) and it decreased significantly for radiographs acquired with DR technology in periods 2 (median: 49 minutes; p < 0.001) and 3 (median∶ 44 minutes; p < 0.001). Overall

Conversion from film to image plates for transfer method neutron radiography of nuclear fuel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Craft, Aaron E.; Papaioannou, Glen C.; Chichester, David L.

This paper summarizes efforts to characterize and qualify a computed radiography (CR) system for neutron radiography of irradiated nuclear fuel at Idaho National Laboratory (INL). INL has multiple programs that are actively developing, testing, and evaluating new nuclear fuels. Irradiated fuel experiments are subjected to a number of sequential post-irradiation examination techniques that provide insight into the overall behavior and performance of the fuel. One of the first and most important of these exams is neutron radiography, which provides more comprehensive information about the internal condition of irradiated nuclear fuel than any other non-destructive technique to date. Results from neutronmore » radiography are often the driver for subsequent examinations of the PIE program. Features of interest that can be evaluated using neutron radiography include irradiation-induced swelling, isotopic and fuel-fragment redistribution, plate deformations, and fuel fracturing. The NRAD currently uses the foil-film transfer technique with film for imaging fuel. INL is pursuing multiple efforts to advance its neutron imaging capabilities for evaluating irradiated fuel and other applications, including conversion from film to CR image plates. Neutron CR is the current state-of-the-art for neutron imaging of highly-radioactive objects. Initial neutron radiographs of various types of nuclear fuel indicate that radiographs can be obtained of comparable image quality currently obtained using film. This paper provides neutron radiographs of representative irradiated fuel pins along with neutron radiographs of standards that informed the qualification of the neutron CR system for routine use. Additionally, this paper includes evaluations of some of the CR scanner parameters and their effects on image quality.« less

Yield of chest radiography after removal of esophageal foreign bodies.

PubMed

Fisher, Jeremy; Mittal, Rohit; Hill, Sarah; Wulkan, Mark L; Clifton, Matthew S

2013-05-01

The aim of this study was to determine the benefit of routine postoperative chest radiography after removal of esophageal foreign bodies in children. Medical records were reviewed of all patients evaluated with an esophageal foreign body at a single children's hospital over 10 years. Operative records and imaging reports were reviewed for evidence of esophageal injury. Of 803 records identified, 690 were included. All underwent rigid esophagoscopy and foreign body removal. The most common items removed were coins (94%), food boluses (3%), and batteries (2%). The rate of esophageal injury was 1.3% (9 patients). No injuries were identified on chest radiographs done as routine or for concern of injury. Patients with operative findings suggestive of an esophageal injury (n = 105) were significantly more likely to have an injury (8.6% vs 0%, P = .0001). Of the 585 children who did not have physical evidence of injury, 40% (n = 235) received a routine chest radiograph. Regardless of the indication, no injuries were identified on chest films. We conclude that intraoperative findings during rigid esophagoscopy suggestive of an injury are predictive of esophageal perforation. Routine chest radiography is not warranted in children who do not meet this criterion. In patients with a concern for injury, we suggest that chest radiography should be deferred in favor of esophagram.

Flash x-ray radiography of argon jets in ambient air

NASA Astrophysics Data System (ADS)

Geiswiller, J.; Robert, E.; Huré, L.; Cachoncinlle, C.; Viladrosa, R.; Pouvesle, J. M.

1998-09-01

This paper describes the development and application of a soft x-ray flash radiography technique. A very compact soft x-ray flash source has been specially designed for these studies. The table-top x-ray source developed in this work emits strong doses, up to one roentgen at the output window, of x-ray photons, with most of them in the characteristic lines of the anode material (photon energy in the energy range 5-10 keV), in pulse of 20 ns FWHM with an x-ray emission zone smaller than 0957-0233/9/9/024/img1. All these characteristics make this source attractive for the x-ray radiography of high-speed phenomena, down to ten nanoseconds duration and/or for the media presenting weak absorption for the harder x-ray photons emitted by more conventional flash x-ray systems. Argon streams in ambient air were chosen as a typical case to enlighten the potentialities of this method. Single-shot radiographs of such an argon jet through rectangular nozzles were obtained. No attempt of quantitative measurement of local density in the argon stream has yet been performed, only the qualitative structure of the jet has been investigated. Nevertheless, these preliminary results enable us to state that the diagnostics of gaseous or plasma media, even at rather low pressures, can proceed using soft x-ray flash radiography.

Experimental comparison between performance of the PM and LPM methods in computed radiography

NASA Astrophysics Data System (ADS)

Kermani, Aboutaleb; Feghhi, Seyed Amir Hossein; Rokrok, Behrouz

2018-07-01

The scatter downgrades the image quality and reduces its information efficiency in quantitative measurement usages when creating projections with ionizing radiation. Therefore, the variety of methods have been applied for scatter reduction and correction of the undesirable effects. As new approaches, the ordinary and localized primary modulation methods have already been used individually through experiments and simulations in medical and industrial computed tomography, respectively. The aim of this study is the evaluation of capabilities and limitations of these methods in comparison with each other. For this mean, the ordinary primary modulation has been implemented in computed radiography for the first time and the potential of both methods has been assessed in thickness measurement as well as scatter to primary signal ratio determination. The comparison results, based on the experimental outputs which obtained using aluminum specimens and continuous X-ray spectra, are to the benefit of the localized primary modulation method because of improved accuracy and higher performance especially at the edges.

Muon radiography in Russia with emulsion technique. First experiments future perspectives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aleksandrov, A. B.; Bagulya, A. V.; Chernyavsky, M. M.

Cosmic ray muon radiography is a novel technique for imaging the internal structures of massive objects. It exploits the capability of high energy muons from cosmic-rays in order to obtain a density map of investigated object and trying to guess information on the variation in the density distribution. Nuclear emulsions are tracking detectors well suited to be employed in this context since they have an excellent angular resolution (few mrad), they are cheap, compact and robust, easily transportable, able to work in harsh environments, and do not require power supply. This work presents the first successful results in the fieldmore » of muon radiography in Russia with nuclear emulsions.« less

No Value for Routine Chest Radiography in the Work-Up of Early Stage Cervical Cancer Patients

PubMed Central

Hoogendam, Jacob P.; Zweemer, Ronald P.; Verkooijen, Helena M.; de Jong, Pim A.; van den Bosch, Maurice A. A. J.; Verheijen, René H. M.; Veldhuis, Wouter B.

2015-01-01

Aim Evidence supporting the recommendation to include chest radiography in the work-up of all cervical cancer patients is limited. We investigated the diagnostic value of routine chest radiography in cervical cancer staging. Methods All consecutive cervical cancer patients who presented at our tertiary referral center in the Netherlands (January 2006 – September 2013), and for whom ≥6 months follow-up was available, were included. As part of the staging procedure, patients underwent a routine two-directional digital chest radiograph. Findings were compared to a composite reference standard consisting of all imaging studies and histology obtained during the 6 months following radiography. Results Of the 402 women who presented with cervical cancer, 288 (71.6%) underwent chest radiography and had ≥6 months follow-up. Early clinical stage (I/II) cervical cancer was present in 244/288 (84.7%) women, while 44 (15.3%) presented with advanced disease (stage III/IV). The chest radiograph of 1 woman – with advanced pre-radiograph stage (IVA) disease – showed findings consistent with pulmonary metastases. Radiographs of 7 other women – 4 early, 3 advanced stage disease – were suspicious for pulmonary metastases which was confirmed by additional imaging in only 1 woman (with pre-radiograph advanced stage (IIIB) disease) and excluded in 6 cases, including all women with early stage disease. In none of the 288 women were thoracic skeletal metastases identified on imaging or during 6 months follow up. Radiography was unremarkable in 76.4% of the study population, and showed findings unrelated to the cervical carcinoma in 21.2%. Conclusion Routine chest radiography was of no value for any of the early stage cervical cancer patients presenting at our tertiary center over a period of 7.7 years. PMID:26135733

No Value for Routine Chest Radiography in the Work-Up of Early Stage Cervical Cancer Patients.

PubMed

Hoogendam, Jacob P; Zweemer, Ronald P; Verkooijen, Helena M; de Jong, Pim A; van den Bosch, Maurice A A J; Verheijen, René H M; Veldhuis, Wouter B

2015-01-01

Evidence supporting the recommendation to include chest radiography in the work-up of all cervical cancer patients is limited. We investigated the diagnostic value of routine chest radiography in cervical cancer staging. All consecutive cervical cancer patients who presented at our tertiary referral center in the Netherlands (January 2006 - September 2013), and for whom ≥6 months follow-up was available, were included. As part of the staging procedure, patients underwent a routine two-directional digital chest radiograph. Findings were compared to a composite reference standard consisting of all imaging studies and histology obtained during the 6 months following radiography. Of the 402 women who presented with cervical cancer, 288 (71.6%) underwent chest radiography and had ≥6 months follow-up. Early clinical stage (I/II) cervical cancer was present in 244/288 (84.7%) women, while 44 (15.3%) presented with advanced disease (stage III/IV). The chest radiograph of 1 woman - with advanced pre-radiograph stage (IVA) disease - showed findings consistent with pulmonary metastases. Radiographs of 7 other women - 4 early, 3 advanced stage disease - were suspicious for pulmonary metastases which was confirmed by additional imaging in only 1 woman (with pre-radiograph advanced stage (IIIB) disease) and excluded in 6 cases, including all women with early stage disease. In none of the 288 women were thoracic skeletal metastases identified on imaging or during 6 months follow up. Radiography was unremarkable in 76.4% of the study population, and showed findings unrelated to the cervical carcinoma in 21.2%. Routine chest radiography was of no value for any of the early stage cervical cancer patients presenting at our tertiary center over a period of 7.7 years.

Dose measurements in intraoral radiography using thermoluminescent dosimeters

NASA Astrophysics Data System (ADS)

Azorín, C.; Azorín, J.; Aguirre, F.; Rivera, T.

2015-01-01

The use of X-ray in medicine demands to expose the patient and the professional to the lowest radiation doses available in agreement with ALARA philosophy. The reference level for intraoral dental radiography is 7 mGy and, in Mexico, a number of examinations of this type are performed annually. It is considered that approximately 25% of all the X-rays examinations carried out in our country correspond to intraoral radiographies. In other hand, most of the intraoral X-ray equipment correspond to conventional radiological systems using film, which are developed as much manual as automatically. In this work the results of determining the doses received by the patients in intraoral radiological examinations made with different radiological systems using LiF:Mg,Cu,P+PTFE thermoluminescent dosimeters are presented. In some conventional radiological systems using film, when films are developed manual or automatically, incident kerma up to 10.61 ± 0.74 mGv were determined. These values exceed that reference level suggested by the IAEA and in the Mexican standards for intraoral examinations.

Optical velocimetry at the Los Alamos Proton Radiography Facility

NASA Astrophysics Data System (ADS)

Tupa, Dale; Tainter, Amy; Neukirch, Levi; Hollander, Brian; Buttler, William; Holtkamp, David; The Los Alamos Proton Radiography Team Team

2016-05-01

The Los Alamos Proton Radiography Facility (pRad) employs a high-energy proton beam to image the properties and behavior of materials driven by high explosives. We will discuss features of pRad and describe some recent experiments, highlighting optical diagnostics for surface velocity measurements.

Experimental investigation of dynamic fragmentation of laser shock-loaded by soft recovery and X-ray radiography

NASA Astrophysics Data System (ADS)

Xin, Jianting; He, Weihua; Chu, Genbai; Gu, Yuqiu

2017-06-01

Dynamic fragmentation of metal under shock pressure is an important issue for both fundamental science and practical applications. And in recent decades, laser provides a promising shock loading technique for investigating the process of dynamic fragmentation under extreme condition application of high strain rate. Our group has performed experimental investigation of dynamic fragmentation under laser shock loading by soft recovery and X-ray radiography at SGC / ó prototype laser facility. The fragments under different loading pressures were recovered by PMP foam and analyzed by X-ray micro-tomography and the improved watershed method. The experiment result showed that the bilinear exponential distribution is more appropriate for representing the fragment size distribution. We also developed X-ray radiography technique. Owing to its inherent advantage over shadowgraph technique, X-ray radiography can potentially determine quantitatively material densities by measuring the X-ray transmission. Our group investigated dynamic process of microjetting by X-ray radiography technique, the recorded radiographic images show clear microjetting from the triangular grooves in the free surface of tin sample.

Lung nodule detection by microdose CT versus chest radiography (standard and dual-energy subtracted).

PubMed

Ebner, Lukas; Bütikofer, Yanik; Ott, Daniel; Huber, Adrian; Landau, Julia; Roos, Justus E; Heverhagen, Johannes T; Christe, Andreas

2015-04-01

The purpose of this study was to investigate the feasibility of microdose CT using a comparable dose as for conventional chest radiographs in two planes including dual-energy subtraction for lung nodule assessment. We investigated 65 chest phantoms with 141 lung nodules, using an anthropomorphic chest phantom with artificial lung nodules. Microdose CT parameters were 80 kV and 6 mAs, with pitch of 2.2. Iterative reconstruction algorithms and an integrated circuit detector system (Stellar, Siemens Healthcare) were applied for maximum dose reduction. Maximum intensity projections (MIPs) were reconstructed. Chest radiographs were acquired in two projections with bone suppression. Four blinded radiologists interpreted the images in random order. A soft-tissue CT kernel (I30f) delivered better sensitivities in a pilot study than a hard kernel (I70f), with respective mean (SD) sensitivities of 91.1%±2.2% versus 85.6%±5.6% (p=0.041). Nodule size was measured accurately for all kernels. Mean clustered nodule sensitivity with chest radiography was 45.7%±8.1% (with bone suppression, 46.1%±8%; p=0.94); for microdose CT, nodule sensitivity was 83.6%±9% without MIP (with additional MIP, 92.5%±6%; p<10(-3)). Individual sensitivities of microdose CT for readers 1, 2, 3, and 4 were 84.3%, 90.7%, 68.6%, and 45.0%, respectively. Sensitivities with chest radiography for readers 1, 2, 3, and 4 were 42.9%, 58.6%, 36.4%, and 90.7%, respectively. In the per-phantom analysis, respective sensitivities of microdose CT versus chest radiography were 96.2% and 75% (p<10(-6)). The effective dose for chest radiography including dual-energy subtraction was 0.242 mSv; for microdose CT, the applied dose was 0.1323 mSv. Microdose CT is better than the combination of chest radiography and dual-energy subtraction for the detection of solid nodules between 5 and 12 mm at a lower dose level of 0.13 mSv. Soft-tissue kernels allow better sensitivities. These preliminary results indicate that

Pleural ultrasonography versus chest radiography for the diagnosis of pneumothorax: review of the literature and meta-analysis.

PubMed

Alrajab, Saadah; Youssef, Asser M; Akkus, Nuri I; Caldito, Gloria

2013-09-23

Ultrasonography is being increasingly utilized in acute care settings with expanding applications. Pneumothorax evaluation by ultrasonography is a fast, safe, easy and inexpensive alternative to chest radiographs. In this review, we provide a comprehensive analysis of the current literature comparing ultrasonography and chest radiography for the diagnosis of pneumothorax. We searched English-language articles in MEDLINE, EMBASE and Cochrane Library dealing with both ultrasonography and chest radiography for diagnosis of pneumothorax. In eligible studies that met strict inclusion criteria, we conducted a meta-analysis to evaluate the diagnostic accuracy of pleural ultrasonography in comparison with chest radiography for the diagnosis of pneumothorax. We reviewed 601 articles and selected 25 original research articles for detailed review. Only 13 articles met all of our inclusion criteria and were included in the final analysis. One study used lung sliding sign alone, 12 studies used lung sliding and comet tail signs, and 6 studies searched for lung point in addition to the other two signs. Ultrasonography had a pooled sensitivity of 78.6% (95% CI, 68.1 to 98.1) and a specificity of 98.4% (95% CI, 97.3 to 99.5). Chest radiography had a pooled sensitivity of 39.8% (95% CI, 29.4 to 50.3) and a specificity of 99.3% (95% CI, 98.4 to 100). Our meta-regression and subgroup analyses indicate that consecutive sampling of patients compared to convenience sampling provided higher sensitivity results for both ultrasonography and chest radiography. Consecutive versus nonconsecutive sampling and trauma versus nontrauma settings were significant sources of heterogeneity. In addition, subgroup analysis showed significant variations related to operator and type of probe used. Our study indicates that ultrasonography is more accurate than chest radiography for detection of pneumothorax. The results support the previous investigations in this field, add new valuable information

Optimum angle-cut of collimator for dense objects in high-energy proton radiography

NASA Astrophysics Data System (ADS)

Xu, Hai-Bo; Zheng, Na

2016-02-01

The use of minus identity lenses with an angle-cut collimator can achieve high contrast images in high-energy proton radiography. This article presents the principles of choosing the angle-cut aperture of the collimator for different energies and objects. Numerical simulation using the Monte Carlo code Geant4 has been implemented to investigate the entire radiography for the French test object. The optimum angle-cut apertures of the collimators are also obtained for different energies. Supported by NSAF (11176001) and Science and Technology Developing Foundation of China Academy of Engineering Physics (2012A0202006)

First experience with x-ray dark-field radiography for human chest imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Noel, Peter B.; Willer, Konstantin; Fingerle, Alexander A.; Gromann, Lukas B.; De Marco, Fabio; Scherer, Kai H.; Herzen, Julia; Achterhold, Klaus; Gleich, Bernhard; Münzel, Daniela; Renz, Martin; Renger, Bernhard C.; Fischer, Florian; Braun, Christian; Auweter, Sigrid; Hellbach, Katharina; Reiser, Maximilian F.; Schröter, Tobias; Mohr, Jürgen; Yaroshenko, Andre; Maack, Hanns-Ingo; Pralow, Thomas; van der Heijden, Hendrik; Proksa, Roland; Köhler, Thomas; Wieberneit, Nataly; Rindt, Karsten; Rummeny, Ernst J.; Pfeiffer, Franz

2017-03-01

Purpose: To evaluate the performance of an experimental X-ray dark-field radiography system for chest imaging in humans and to compare with conventional diagnostic imaging. Materials and Methods: The study was institutional review board (IRB) approved. A single human cadaver (52 years, female, height: 173 cm, weight: 84 kg, chest circumference: 97 cm) was imaged within 24 hours post mortem on the experimental x-ray dark-field system. In addition, the cadaver was imaged on a clinical CT system to obtain a reference scan. The grating-based dark-field radiography setup was equipped with a set of three gratings to enable grating-based dark-field contrast x-ray imaging. The prototype operates at an acceleration voltage of up to 70 kVp and with a field-of-view large enough for clinical chest x-ray (>35 x 35 cm2). Results: It was feasible to extract x-ray dark-field signal of the whole human thorax, clearly demonstrating that human x-ray dark-field chest radiography is feasible. Lung tissue produced strong scattering, reflected in a pronounced x-ray dark-field signal. The ribcage and the backbone are less prominent than the lung but are also distinguishable. Finally, the soft tissue is not present in the dark-field radiography. The regions of the lungs affected by edema, as verified by CT, showed less dark-field signal compared to healthy lung tissue. Conclusion: Our results reveal the current status of translating dark-field imaging from a micro (small animal) scale to a macro (patient) scale. The performance of the experimental x-ray dark-field radiography setup offers, for the first time, obtaining multi-contrast chest x-ray images (attenuation and dark-field signal) from a human cadaver.

Mobile radiography services in nursing homes: a systematic review of residents' and societal outcomes.

PubMed

Kjelle, Elin; Lysdahl, Kristin Bakke

2017-03-23

Demographic changes are leading to an ageing population in Europe, and predict an increase in the number of nursing home residents over the next 30 years. Nursing home residents need specialised healthcare services such as radiology due to both chronic and acute illnesses. Mobile radiography, x-ray examinations performed in the nursing homes, may be a good way of providing services to this population. The aim of this systematic review was to identify the outcomes of mobile radiography services for nursing home residents and society. A systematic review based on searches in the Medline, Cochrane, PubMed, Embase and Svemed + databases was performed. Titles and abstracts were screened according to a predefined set of inclusion criteria: empirical studies in the geriatric population, and reports of mobile radiography services in a clinical setting. All publications were quality appraised using MMAT or CASP appraisal tools. Data were extracted using a summary table and results were narratively synthesised. Ten publications were included. Three overarching outcomes were identified: 1) reduced number of hospitalisations and outpatient examinations or treatments, 2) reduced number of transfers between nursing homes and hospitals and 3) increased access to x-ray examinations. These outcomes were interlinked with the more specific outcomes for residents and society reported in the literature. For residents there was a reduction in burdensome transfers and waiting time and adequate treatment and care increased. For society, released resources could be used more efficiently, and overall costs were reduced substantially. This review indicates that mobile radiography services for nursing home residents in the western world are of comparable quality to hospital-based examinations and have clear potential benefits. Mobile radiography reduced transfers to and from hospital, increased the number of examinations carried out and facilitated timely diagnosis and access to

Diagnostic Accuracy of Ultrasonography and Radiography in Initial Evaluation of Chest Trauma Patients.

PubMed

Vafaei, Ali; Hatamabadi, Hamid Reza; Heidary, Kamran; Alimohammadi, Hosein; Tarbiyat, Mohammad

2016-01-01

Application of chest radiography for all multiple trauma patients is associated with a significant increase in total costs, exposure to radiation, and overcrowding of the emergency department. Ultrasound has been introduced as an alternative diagnostic tool in this regard. The aim of the present study is to compare the diagnostic accuracy of chest ultrasonography and radiography in detection of traumatic intrathoracic injuries. In the present prospective cross-sectional study, patients with traumatic intrathoracic injuries, who were referred to the emergency department from December 2013 to December 2014, were assessed. The patients underwent bedside ultrasound, radiographic and computed tomography (CT) scan examinations based on ATLS recommendations. Screening performance characteristics of ultrasonography and radiography were compared using SPSS 21.0. Chest CT scan was considered as gold standard. 152 chest trauma patients with a mean age of 31.4 ± 13.8 years (range: 4 ‒ 67), were enrolled (77.6% male). Chest CT scan showed pulmonary contusion in 48 (31.6%) patients, hemothorax in 29 (19.1%), and pneumothorax in 55 (36.2%) cases. Area under the ROC curve of ultrasonography in detection of pneumothorax, hemothorax, and pulmonary contusion were 0.91 (95% CI: 0.86‒0.96), 0.86 (95% CI: 0.78‒0.94), and 0.80 (95% CI: 0.736‒0.88), respectively. Area under the ROC curve of radiography was 0.80 (95% CI: 0.736‒0.87) for detection of pneumothorax, 0.77 (95% CI: 0.68‒0.86) for hemothorax, and 0.58 (95% CI: 0.5‒0.67) for pulmonary contusion. Comparison of areas under the ROC curve declared the significant superiority of ultrasonography in detection of pneumothorax (p = 0.02) and pulmonary contusion (p < 0.001). However, the diagnostic value of the two tests was equal in detection of hemothorax (p = 0.08). The results of the present study showed that ultrasonography is preferable to radiography in the initial evaluation of patients with traumatic injuries to the

5. INTERIOR VIEW, SHOWING A CONTROL ROOM INSIDE THE RADIOGRAPHY ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. INTERIOR VIEW, SHOWING A CONTROL ROOM INSIDE THE RADIOGRAPHY ROOM; PASS-THROUGH FOR EXPOSED FILM ON RIGHT - Fort McCoy, Building No. T-1031, North side of South Tenth Avenue, Block 10, Sparta, Monroe County, WI

Proton Radiography of a Thermal Explosion in PBX9501

NASA Astrophysics Data System (ADS)

Smilowitz, L.; Henson, B. F.; Romero, J. J.; Sandstrom, M. M.; Asay, B. W.; Schwartz, C.; Saunders, A.; Merrill, F.; Morris, C.; Murray, M. M.; McNeil, W. V.; Marr-Lyon, M.; Rightley, P. M.

2007-12-01

The understanding of thermal explosions and burn propagation lags that of detonations and shock propagation. Diagnostics such as high energy radiography have been used to image shocks, but have been previously precluded from use in thermal explosions due to their stringent timing requirements: shock propagation can be synchronized to an external diagnostic while thermal explosion can not. This issue is solved by following the evolution of the ignition volume in a thermal explosion and using a laser pulse to provide a temperature jump in that central volume during the final thermal runaway leading to ignition. Thermal explosion experiments have been conducted at the Los Alamos Proton Radiography facility and have yielded images of the evolution of ignition, post-ignition burn propagation, and case failure in a radially confined cylinder of PBX 9501. This paper presents images taken during the hours long quasistatic heating, the final minutes of thermal runaway, and the post ignition burn propagation.

Proton radiography and tomography with application to proton therapy

PubMed Central

Allinson, N M; Evans, P M

2015-01-01

Proton radiography and tomography have long promised benefit for proton therapy. Their first suggestion was in the early 1960s and the first published proton radiographs and CT images appeared in the late 1960s and 1970s, respectively. More than just providing anatomical images, proton transmission imaging provides the potential for the more accurate estimation of stopping-power ratio inside a patient and hence improved treatment planning and verification. With the recent explosion in growth of clinical proton therapy facilities, the time is perhaps ripe for the imaging modality to come to the fore. Yet many technical challenges remain to be solved before proton CT scanners become commonplace in the clinic. Research and development in this field is currently more active than at any time with several prototype designs emerging. This review introduces the principles of proton radiography and tomography, their historical developments, the raft of modern prototype systems and the primary design issues. PMID:26043157

A note on digital dental radiography in forensic odontology.

PubMed

Chiam, Sher-Lin

2014-09-01

Digital dental radiography, intraoral and extraoral, is becoming more popular in dental practice. It offers convenience, such as lower exposure to radiation, ease of storing of images, and elimination of chemical processing. However, it also has disadvantages and drawbacks. One of these is the potential for confusion of the orientation of the image. This paper outlines one example of this, namely, the lateral inversion of the image. This source of confusion is partly inherent in the older model of phosphor storage plates (PSPs), as they allow both sides to be exposed without clue to the fact that the image is acquired on the wrong side. The native software allows digital manipulation of the X-ray image, permitting both rotation and inversion. Attempts to orientate the X-ray according to the indicator incorporated on the plate can then sometimes lead to inadvertent lateral inversion of the image. This article discusses the implications of such mistakes in dental digital radiography to forensic odontology and general dental practice.

Reliability of landmark identification in cephalometric radiography acquired by a storage phosphor imaging system.

PubMed

Chen, Y-J; Chen, S-K; Huang, H-W; Yao, C-C; Chang, H-F

2004-09-01

To compare the cephalometric landmark identification on softcopy and hardcopy of direct digital cephalography acquired by a storage-phosphor (SP) imaging system. Ten digital cephalograms and their conventional counterpart, hardcopy on a transparent blue film, were obtained by a SP imaging system and a dye sublimation printer. Twelve orthodontic residents identified 19 cephalometric landmarks on monitor-displayed SP digital images with computer-aided method and on their hardcopies with conventional method. The x- and y-coordinates for each landmark, indicating the horizontal and vertical positions, were analysed to assess the reliability of landmark identification and evaluate the concordance of the landmark locations in softcopy and hardcopy of SP digital cephalometric radiography. For each of the 19 landmarks, the location differences as well as the horizontal and vertical components were statistically significant between SP digital cephalometric radiography and its hardcopy. Smaller interobserver errors on SP digital images than those on their hardcopies were noted for all the landmarks, except point Go in vertical direction. The scatter-plots demonstrate the characteristic distribution of the interobserver error in both horizontal and vertical directions. Generally, the dispersion of interobserver error on SP digital cephalometric radiography is less than that on its hardcopy with conventional method. The SP digital cephalometric radiography could yield better or comparable level of performance in landmark identification as its hardcopy, except point Go in vertical direction.

Calculation of the cardiothoracic ratio from portable anteroposterior chest radiography.

PubMed

Chon, Sung Bin; Oh, Won Sup; Cho, Jun Hwi; Kim, Sam Soo; Lee, Seung-Joon

2011-11-01

Cardiothoracic ratio (CTR), the ratio of cardiac diameter (CD) to thoracic diameter (TD), is a useful screening method to detect cardiomegaly, but is reliable only on posteroanterior chest radiography (chest PA). We performed this cross-sectional 3-phase study to establish reliable CTR from anteroposterior chest radiography (chest AP). First, CD(Chest PA)/CD(Chest AP) ratios were determined at different radiation distances by manipulating chest computed tomography to simulate chest PA and AP. CD(Chest PA) was inferred from multiplying CD(Chest AP) by this ratio. Incorporating this CD and substituting the most recent TD(Chest PA), we calculated the 'corrected' CTR and compared it with the conventional one in patients who took both the chest radiographies. Finally, its validity was investigated among the critically ill patients who performed portable chest AP. CD(Chest PA)/CD(Chest AP) ratio was {0.00099 × (radiation distance [cm])} + 0.79 (n = 61, r = 1.00, P < 0.001). The corrected CTR was highly correlated with the conventional one (n = 34, difference: 0.00016 ± 0.029; r = 0.92, P < 0.001). It was higher in congestive than non-congestive patients (0.53 ± 0.085; n = 38 vs 0.49 ± 0.061; n = 46, P = 0.006). Its sensitivity and specificity was 61% and 54%. In summary, reliable CTR can be calculated from chest AP with an available previous chest PA. This might help physicians detect congestive cardiomegaly for patients undergoing portable chest AP.

[Gonad protective effect of radiation protective apron in chest radiography].

PubMed

Hashimoto, Masatoshi; Kato, Hideyuki; Fujibuchi, Toshiou; Ochi, Shigehiro; Morita, Fuminori

2004-12-01

Depending on the facility, a radiation protective apron (protector) is used to protect the gonad from radiation exposure in chest radiography. To determine the necessity of using a protector during chest radiography, we measured the effect of the protector on the gonad in this study. First, using a human body phantom, we measured the absorbed dose of the female gonad with and without the protector, using a thermoluminescence dosimeter (TLD), and confirmed its protective effect. Using the protector, the absorbed dose was reduced to 28+/-2% and 39+/-4% for field sizes of 14 x 17 inch and 14 x 14 inch, respectively. Next, we used Monte Carlo simulation and confirmed, not only the validity of the actual measurement values, but also the fact that the influence of radiation on the absorbed dose of the gonad was mostly from scattered radiation from inside the body for the 14 x 17 inch field size, and also from the X-ray tube for the 14 x 14 inch field size. Although a certain protective effect is achieved by using the protector, the radiation dose to the gonad is only a few microGy even without a protector. Thus, the risk of a genetic effect would be as small as 10(-8). Given that acceptable risk is below 10(-6), we conclude the use of a radiation protective apron is not necessary for diagnostic chest radiography.

Calculation of the Cardiothoracic Ratio from Portable Anteroposterior Chest Radiography

PubMed Central

Chon, Sung Bin; Oh, Won Sup; Cho, Jun Hwi; Kim, Sam Soo

2011-01-01

Cardiothoracic ratio (CTR), the ratio of cardiac diameter (CD) to thoracic diameter (TD), is a useful screening method to detect cardiomegaly, but is reliable only on posteroanterior chest radiography (chest PA). We performed this cross-sectional 3-phase study to establish reliable CTR from anteroposterior chest radiography (chest AP). First, CDChest PA/CDChest AP ratios were determined at different radiation distances by manipulating chest computed tomography to simulate chest PA and AP. CDChest PA was inferred from multiplying CDChest AP by this ratio. Incorporating this CD and substituting the most recent TDChest PA, we calculated the 'corrected' CTR and compared it with the conventional one in patients who took both the chest radiographies. Finally, its validity was investigated among the critically ill patients who performed portable chest AP. CDChest PA/CDChest AP ratio was {0.00099 × (radiation distance [cm])} + 0.79 (n = 61, r = 1.00, P < 0.001). The corrected CTR was highly correlated with the conventional one (n = 34, difference: 0.00016 ± 0.029; r = 0.92, P < 0.001). It was higher in congestive than non-congestive patients (0.53 ± 0.085; n = 38 vs 0.49 ± 0.061; n = 46, P = 0.006). Its sensitivity and specificity was 61% and 54%. In summary, reliable CTR can be calculated from chest AP with an available previous chest PA. This might help physicians detect congestive cardiomegaly for patients undergoing portable chest AP. PMID:22065900

Application of Digital Radiography to Weld Inspection for the Space Shuttle External Fuel Tank

NASA Technical Reports Server (NTRS)

Ussery, Warren

2009-01-01

This slide presentation reviews NASA's use of digital radiography to inspect the welds of the external tanks used to hold the cryogenic fuels for the Space Shuttle Main Engines. NASA has had a goal of replacing a significant portion of film used to inspect the welds, with digital radiography. The presentation reviews the objectives for converting to a digital system from film, the characteristics of the digital system, the Probability of detection study, the qualification and implementation of the system.

Urethral Stenting for Obstructive Uropathy Utilizing Digital Radiography for Guidance: Feasibility and Clinical Outcome in 26 Dogs.

PubMed

Radhakrishnan, A

2017-03-01

Urethral stent placement is an interventional treatment option to alleviate urethral outflow obstruction. It has been described utilizing fluoroscopy, but fluoroscopy is not as readily available in private practice as digital radiography. To describe the use of digital radiography for urethral stent placement in dogs with obstructive uropathy. Twenty-six client-owned dogs presented for dysuria associated with benign and malignant causes of obstructive uropathy that underwent urethral stent placement. Retrospective study. Causes of obstructive uropathy included transitional cell carcinoma, prostatic carcinoma, hemangiosarcoma, obstructive proliferative urethritis, compressive vaginal leiomyosarcoma, and detrusor-sphincter dyssynergia. Survival time range was 1-48 months (median, 5 months). All dogs were discharged from the hospital with urine outflow restored. Intraprocedural complications included guide wire penetration of the urethral wall in 1 dog and improper stent placement in a second dog. Both complications were successfully managed at the time of the procedure with no follow-up problems noted in either patient. Urethral stent placement can be successfully performed utilizing digital radiography. The complications experienced can be avoided by more cautious progression with each step through the procedure and serial radiography. The application of digital radiography may allow treatment of urethral obstruction to become more readily available. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Neutron collimator design of neutron radiography based on the BNCT facility

NASA Astrophysics Data System (ADS)

Yang, Xiao-Peng; Yu, Bo-Xiang; Li, Yi-Guo; Peng, Dan; Lu, Jin; Zhang, Gao-Long; Zhao, Hang; Zhang, Ai-Wu; Li, Chun-Yang; Liu, Wan-Jin; Hu, Tao; Lü, Jun-Guang

2014-02-01

For the research of CCD neutron radiography, a neutron collimator was designed based on the exit of thermal neutron of the Boron Neutron Capture Therapy (BNCT) reactor. Based on the Geant4 simulations, the preliminary choice of the size of the collimator was determined. The materials were selected according to the literature data. Then, a collimator was constructed and tested on site. The results of experiment and simulation show that the thermal neutron flux at the end of the neutron collimator is greater than 1.0×106 n/cm2/s, the maximum collimation ratio (L/D) is 58, the Cd-ratio(Mn) is 160 and the diameter of collimator end is 10 cm. This neutron collimator is considered to be applicable for neutron radiography.

Factors affecting general practitioners' decisions about plain radiography for back pain: implications for classification of guideline barriers--a qualitative study.

PubMed

Espeland, Ansgar; Baerheim, Anders

2003-03-24

General practitioners often diverge from clinical guidelines regarding spine radiography. This study aimed to identify and describe A) factors general practitioners consider may affect their decisions about ordering plain radiography for back pain and B) barriers to guideline adherence suggested by such factors. Focus group interviews regarding factors affecting ordering decisions were carried out on a diverse sample of Norwegian general practitioners and were analysed qualitatively. Results of this study and two qualitative studies from the Netherlands and USA on use of spine radiography were interpreted for barriers to guideline adherence. These were compared with an existing barrier classification system described by Dr Cabana's group. The factors which Norwegian general practitioners considered might affect their decisions about ordering plain radiography for back pain concerned the following broader issues: clinical ordering criteria, patients' wishes for radiography and the general practitioner's response, uncertainty, professional dignity, access to radiology services, perception of whether the patient really was ill, sense of pressure from other health care providers/social security, and expectations about the consequences of ordering radiography. The three studies suggested several attitude-related and external barriers as classified in a previously reported system described by Dr Cabana in another study. Identified barriers not listed in this system were: lack of expectancy that guideline adherence will lead to desired health care process, emotional difficulty with adherence, improper access to actual/alternative health care services, and pressure from health care providers/organisations. Our findings may help implement spine radiography guidelines. They also indicate that Cabana et al.'s barrier classification system needs extending. A revised system is proposed.

Real-time radiography at the NECTAR facility

NASA Astrophysics Data System (ADS)

Bücherl, T.; Lierse von Gostomski, Ch.

2011-09-01

A feasibility study has shown that real-time radiography using fission neutrons is possible at the NECTAR facility, when using an improved detection system for fast variations (Bücherl et al., 2009 [1]). Continuing this study, real-time measurements of slowly varying processes like the water uptake in medium sized trunks (diameter about 12 cm) and of slow periodic processes (e.g. a slowly rotating iron disk) are investigated successfully using the existing detection system.

Digital Radiography Qualification of Tube Welding

NASA Technical Reports Server (NTRS)

Carl, Chad

2012-01-01

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

Comparison of Diagnostic Accuracy of Radiation Dose-Equivalent Radiography, Multidetector Computed Tomography and Cone Beam Computed Tomography for Fractures of Adult Cadaveric Wrists

PubMed Central

Neubauer, Jakob; Benndorf, Matthias; Reidelbach, Carolin; Krauß, Tobias; Lampert, Florian; Zajonc, Horst; Kotter, Elmar; Langer, Mathias; Fiebich, Martin; Goerke, Sebastian M.

2016-01-01

Purpose To compare the diagnostic accuracy of radiography, to radiography equivalent dose multidetector computed tomography (RED-MDCT) and to radiography equivalent dose cone beam computed tomography (RED-CBCT) for wrist fractures. Methods As study subjects we obtained 10 cadaveric human hands from body donors. Distal radius, distal ulna and carpal bones (n = 100) were artificially fractured in random order in a controlled experimental setting. We performed radiation dose equivalent radiography (settings as in standard clinical care), RED-MDCT in a 320 row MDCT with single shot mode and RED-CBCT in a device dedicated to musculoskeletal imaging. Three raters independently evaluated the resulting images for fractures and the level of confidence for each finding. Gold standard was evaluated by consensus reading of a high-dose MDCT. Results Pooled sensitivity was higher in RED-MDCT with 0.89 and RED-MDCT with 0.81 compared to radiography with 0.54 (P = < .004). No significant differences were detected concerning the modalities’ specificities (with values between P = .98). Raters' confidence was higher in RED-MDCT and RED-CBCT compared to radiography (P < .001). Conclusion The diagnostic accuracy of RED-MDCT and RED-CBCT for wrist fractures proved to be similar and in some parts even higher compared to radiography. Readers are more confident in their reporting with the cross sectional modalities. Dose equivalent cross sectional computed tomography of the wrist could replace plain radiography for fracture diagnosis in the long run. PMID:27788215

Comparison of radiography and magnetic resonance imaging for evaluating the extent of nasal neoplasia in dogs.

PubMed

Petite, A F B; Dennis, R

2006-09-01

Magnetic resonance imaging (MRI) is increasingly used in veterinary practice and, in some centres, is part of the diagnostic work-up of small animals with nasal disease. However, there are no published studies which critically evaluate the use of magnetic resonance imaging for this purpose. The purpose of this work was to assess the changes seen using magnetic resonance imaging and to compare them with radiography. The study included 12 dogs that had undergone both radiography and magnetic resonance imaging of the nasal cavity and had a histopathological diagnosis of malignant nasal neoplasia. Two pairs of board-certified radiologists scored the radiographs and the MRI scans, evaluating 10 signs of abnormality using a simple scoring system. Magnetic resonance imaging features were described in detail, and radiographic and magnetic resonance imaging scores for each sign as well as total scores were compared. Magnetic resonance imaging often showed that the tumour was more extensive than it had appeared on radiography but occasionally showed that radiographs had overestimated its size. Although radiography was reliable for assessment of the presence and size of a mass and for the extent of turbinate destruction, it usually failed to show occlusion of the major airway passages that were evident on magnetic resonance imaging. Extension of the tumour into the opposite nasal cavity, frontal sinus, orbit and cranial cavity was shown much better on magnetic resonance imaging. Minor but significant extension beyond the nasal cavity, which is important for treatment planning and prognosis, requires magnetic resonance imaging for demonstration, although radiography shows major changes reliably.

X-ray vector radiography of a human hand

NASA Astrophysics Data System (ADS)

Jud, Christoph; Braig, Eva; Dierolf, Martin; Eggl, Elena; Günther, Benedikt; Achterhold, Klaus; Gleich, Bernhard; Rummeny, Ernst; Noël, Peter; Pfeiffer, Franz; Münzel, Daniela

2017-03-01

Grating based x-ray phase-contrast reveals differential phase-contrast (DPC) and dark-field contrast (DFC) on top of the conventional absorption image. X-ray vector radiography (XVR) exploits the directional dependence of the DFC and yields the mean scattering strength, the degree of anisotropy and the orientation of scattering structures by combining several DFC-projections. Here, we perform an XVR of an ex vivo human hand specimen. Conventional attenuation images have a good contrast between the bones and the surrounding soft tissue. Within the bones, trabecular structures are visible. However, XVR detects subtler differences within the trabecular structure: there is isotropic scattering in the extremities of the phalanx in contrast to anisotropic scattering in its body. The orientation changes as well from relatively random in the extremities to an alignment along the longitudinal trabecular orientation in the body. In the other bones measured, a similar behavior was found. These findings indicate a deeper insight into the anatomical configuration using XVR compared to conventional radiography. Since microfractures cause a discontinuous trabecular structure, XVR could help to detect so-called radiographically occult fractures of the trabecular bones.

A maximum likelihood method for high resolution proton radiography/proton CT

NASA Astrophysics Data System (ADS)

Collins-Fekete, Charles-Antoine; Brousmiche, Sébastien; Portillo, Stephen K. N.; Beaulieu, Luc; Seco, Joao

2016-12-01

Multiple Coulomb scattering (MCS) is the largest contributor to blurring in proton imaging. In this work, we developed a maximum likelihood least squares estimator that improves proton radiography’s spatial resolution. The water equivalent thickness (WET) through projections defined from the source to the detector pixels were estimated such that they maximizes the likelihood of the energy loss of every proton crossing the volume. The length spent in each projection was calculated through the optimized cubic spline path estimate. The proton radiographies were produced using Geant4 simulations. Three phantoms were studied here: a slanted cube in a tank of water to measure 2D spatial resolution, a voxelized head phantom for clinical performance evaluation as well as a parametric Catphan phantom (CTP528) for 3D spatial resolution. Two proton beam configurations were used: a parallel and a conical beam. Proton beams of 200 and 330 MeV were simulated to acquire the radiography. Spatial resolution is increased from 2.44 lp cm-1 to 4.53 lp cm-1 in the 200 MeV beam and from 3.49 lp cm-1 to 5.76 lp cm-1 in the 330 MeV beam. Beam configurations do not affect the reconstructed spatial resolution as investigated between a radiography acquired with the parallel (3.49 lp cm-1 to 5.76 lp cm-1) or conical beam (from 3.49 lp cm-1 to 5.56 lp cm-1). The improved images were then used as input in a photon tomography algorithm. The proton CT reconstruction of the Catphan phantom shows high spatial resolution (from 2.79 to 5.55 lp cm-1 for the parallel beam and from 3.03 to 5.15 lp cm-1 for the conical beam) and the reconstruction of the head phantom, although qualitative, shows high contrast in the gradient region. The proposed formulation of the optimization demonstrates serious potential to increase the spatial resolution (up by 65 % ) in proton radiography and greatly accelerate proton computed tomography reconstruction.

Trochoidal X-ray Vector Radiography: Directional dark-field without grating stepping

NASA Astrophysics Data System (ADS)

Sharma, Y.; Bachche, S.; Kageyama, M.; Kuribayashi, M.; Pfeiffer, F.; Lasser, T.; Momose, A.

2018-03-01

X-ray Vector Radiography (XVR) is an imaging technique that reveals the orientations of sub-pixel sized structures within a sample. Several dark-field radiographs are acquired by rotating the sample around the beam propagation direction and stepping one of the gratings to several positions for every pose of the sample in an X-ray grating interferometry setup. In this letter, we present a method of performing XVR of a continuously moving sample without the need of any grating motion. We reconstruct the orientations within a sample by analyzing the change in the background moire fringes caused by the sample moving and simultaneously rotating in plane (trochoidal trajectory) across the detector field-of-view. Avoiding the motion of gratings provides significant advantages in terms of stability and repeatability, while the continuous motion of the sample makes this kind of system adaptable for industrial applications such as the scanning of samples on a conveyor belt. Being the first step in the direction of utilizing advanced sample trajectories to replace grating motion, this work also lays the foundations for a full three dimensional reconstruction of scattering function without grating motion.

42 CFR Appendix G to Part 75 - Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 1 2013-10-01 2013-10-01 false Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography G Appendix G to Part 75 Public Health PUBLIC HEALTH SERVICE...—Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography The following section...

42 CFR Appendix G to Part 75 - Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 1 2011-10-01 2011-10-01 false Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography G Appendix G to Part 75 Public Health PUBLIC HEALTH SERVICE...—Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography The following section...

42 CFR Appendix G to Part 75 - Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 1 2012-10-01 2012-10-01 false Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography G Appendix G to Part 75 Public Health PUBLIC HEALTH SERVICE...—Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography The following section...

42 CFR Appendix G to Part 75 - Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 1 2014-10-01 2014-10-01 false Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography G Appendix G to Part 75 Public Health PUBLIC HEALTH SERVICE...—Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography The following section...

42 CFR Appendix G to Part 75 - Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography G Appendix G to Part 75 Public Health PUBLIC HEALTH SERVICE...—Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography The following section...

The use of intrathecal analgesia and contrast radiography as preoperative diagnostic methods for digital flexor tendon sheath pathology.

PubMed

Fiske-Jackson, A R; Barker, W H J; Eliashar, E; Foy, K; Smith, R K W

2013-01-01

The sensitivity of ultrasonography for the diagnosis of manica flexoria (MF) tears within the digital flexor tendon sheath (DFTS) is lower than for diagnosis of marginal tears of the deep digital flexor tendon (DDFT). Additional diagnostic tools would assist in appropriate decision making for either conservative or surgical management. To evaluate the improvement in lameness of horses with MF or DDFT tears following intrathecal analgesia and to assess the sensitivity and specificity of contrast radiography for the diagnosis of these tears. The case records of horses presented to a referral clinic over a 7-year period that underwent intrathecal diagnostic analgesia, or intrathecal analgesia and contrast radiography, of the DFTS with subsequent tenoscopy were examined. Fifty-three limbs had intrathecal diagnostic analgesia performed and 23 contrast tenograms were assessed in horses undergoing DFTS tenoscopy. Horses with DDFT tears were significantly more likely to respond positively to intrathecal diagnostic analgesia than those with MF tears (P = 0.02). Using contrast radiography, tears of the MF were predicted with an overall sensitivity of 96% and specificity of 80%; marginal tears of the DDFT were predicted with an overall sensitivity of 57% and specificity of 84%. The results of intrathecal analgesia of the DFTS in combination with contrast radiography have a high sensitivity for predicting MF tears. The sensitivity of contrast radiography for predicting tears of the DDFT is lower but the specificity remains high. Contrast radiography performed at the same time as intrathecal analgesia provides useful information regarding the presence of MF tears and DDFT tears, which can assist in the decision of whether to manage the lameness conservatively or with tenoscopic evaluation. © 2012 EVJ Ltd.

Development of fast neutron radiography system based on portable neutron generator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yi, Chia Jia, E-mail: gei-i-kani@hotmail.com; Nilsuwankosit, Sunchai, E-mail: sunchai.n@chula.ac.th

Due to the high installation cost, the safety concern and the immobility of the research reactors, the neutron radiography system based on portable neutron generator is proposed. Since the neutrons generated from a portable neutron generator are mostly the fast neutrons, the system is emphasized on using the fast neutrons for the purpose of conducting the radiography. In order to suppress the influence of X-ray produced by the neutron generator, a combination of a shielding material sandwiched between two identical imaging plates is used. A binary XOR operation is then applied for combining the information from the imaging plates. Themore » raw images obtained confirm that the X-ray really has a large effect and that XOR operation can help enhance the effect of the neutrons.« less

Cumulative radiation exposure and associated cancer risk estimates for scoliosis patients: Impact of repetitive full spine radiography.

PubMed

Law, Martin; Ma, Wang-Kei; Lau, Damian; Chan, Eva; Yip, Lawrance; Lam, Wendy

2016-03-01

To quantitatively evaluate the cumulative effective dose and associated cancer risk for scoliotic patients undergoing repetitive full spine radiography during their diagnosis and follow up periods. Organ absorbed doses of full spine exposed scoliotic patients at different age were computer simulated with the use of PCXMC software. Gender specific effective dose was then calculated with the ICRP-103 approach. Values of lifetime attributable cancer risk for patients exposed at different age were calculated for both patient genders and for Asian and Western population. Mathematical fitting for effective dose and for lifetime attributable cancer risk, as function of exposed age, was analytically obtained to quantitatively estimate patient cumulated effective dose and cancer risk. The cumulative effective dose of full spine radiography with posteroanterior and lateral projection for patients exposed annually at age between 5 and 30 years using digital radiography system was calculated as 15mSv. The corresponding cumulative lifetime attributable cancer risk for Asian and Western population was calculated as 0.08-0.17%. Female scoliotic patients would be at a statistically significant higher cumulated cancer risk than male patients under the same full spine radiography protocol. We demonstrate the use of computer simulation and analytic formula to quantitatively obtain the cumulated effective dose and cancer risk at any age of exposure, both of which are valuable information to medical personnel and patients' parents concern about radiation safety in repetitive full spine radiography. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

An atlas-based organ dose estimator for tomosynthesis and radiography

NASA Astrophysics Data System (ADS)

Hoye, Jocelyn; Zhang, Yakun; Agasthya, Greeshma; Sturgeon, Greg; Kapadia, Anuj; Segars, W. Paul; Samei, Ehsan

2017-03-01

The purpose of this study was to provide patient-specific organ dose estimation based on an atlas of human models for twenty tomosynthesis and radiography protocols. The study utilized a library of 54 adult computational phantoms (age: 18-78 years, weight 52-117 kg) and a validated Monte-Carlo simulation (PENELOPE) of a tomosynthesis and radiography system to estimate organ dose. Positioning of patient anatomy was based on radiographic positioning handbooks. The field of view for each exam was calculated to include relevant organs per protocol. Through simulations, the energy deposited in each organ was binned to estimate normalized organ doses into a reference database. The database can be used as the basis to devise a dose calculator to predict patient-specific organ dose values based on kVp, mAs, exposure in air, and patient habitus for a given protocol. As an example of the utility of this tool, dose to an organ was studied as a function of average patient thickness in the field of view for a given exam and as a function of Body Mass Index (BMI). For tomosynthesis, organ doses can also be studied as a function of x-ray tube position. This work developed comprehensive information for organ dose dependencies across tomosynthesis and radiography. There was a general exponential decrease dependency with increasing patient size that is highly protocol dependent. There was a wide range of variability in organ dose across the patient population, which needs to be incorporated in the metrology of organ dose.

Assessment of periodontal bone level revisited: a controlled study on the diagnostic accuracy of clinical evaluation methods and intra-oral radiography.

PubMed

Christiaens, Véronique; De Bruyn, Hugo; Thevissen, Eric; Koole, Sebastiaan; Dierens, Melissa; Cosyn, Jan

2018-01-01

The accuracy of analogue and especially digital intra-oral radiography in assessing interdental bone level needs further documentation. The aim of this study was to compare clinical and radiographic bone level assessment to intra-surgical bone level registration (1) and to identify the clinical variables rendering interdental bone level assessment inaccurate (2). The study sample included 49 interdental sites in 17 periodontitis patients. Evaluation methods included vertical relative probing attachment level (RAL-V), analogue and digital intra-oral radiography and bone sounding without and with flap elevation. The latter was considered the true bone level. Five examiners evaluated all radiographs. Significant underestimation of the true bone level was observed for all evaluation methods pointing to 2.7 mm on average for analogue radiography, 2.5 mm for digital radiography, 1.8 mm for RAL-V and 0.6 mm for bone sounding without flap elevation (p < 0.001). Radiographic underestimation of the true bone level was higher in the (pre)molar region (p ≤ 0.047) and increased with defect depth (p < 0.001). Variation between clinicians was huge (range analogue radiography 2.2-3.2 mm; range digital radiography 2.1-3.0 mm). All evaluation methods significantly underestimated the true bone level. Bone sounding was most accurate, whereas intra-oral radiographs were least accurate. Deep periodontal defects in the (pre)molar region were most underrated by intra-oral radiography. Bone sounding had the highest accuracy in assessing interdental bone level.

Absorbed organ and effective doses from digital intra-oral and panoramic radiography applying the ICRP 103 recommendations for effective dose estimations

PubMed Central

Thilander-Klang, Anne; Ylhan, Betȕl; Lofthag-Hansen, Sara; Ekestubbe, Annika

2016-01-01

Objective: During dental radiography, the salivary and thyroid glands are at radiation risk. In 2007, the International Commission on Radiological Protection (ICRP) updated the methodology for determining the effective dose, and the salivary glands were assigned tissue-specific weighting factors for the first time. The aims of this study were to determine the absorbed dose to the organs and to calculate, applying the ICRP publication 103 tissue-weighting factors, the effective doses delivered during digital intraoral and panoramic radiography. Methods: Thermoluminescent dosemeter measurements were performed on an anthropomorphic head and neck phantom. The organ-absorbed doses were measured at 30 locations, representing different radiosensitive organs in the head and neck, and the effective dose was calculated according to the ICRP recommendations. Results: The salivary glands and the oral mucosa received the highest absorbed doses from both intraoral and panoramic radiography. The effective dose from a full-mouth intraoral examination was 15 μSv and for panoramic radiography, the effective dose was in the range of 19–75 μSv, depending on the panoramic equipment used. Conclusion: The effective dose from a full-mouth intraoral examination is lower and that from panoramic radiography is higher than previously reported. Clinicians should be aware of the higher effective dose delivered during panoramic radiography and the risk–benefit profile of this technique must be assessed for the individual patient. Advances in knowledge: The effective dose of radiation from panoramic radiography is higher than previously reported and there is large variability in the delivered radiation dosage among the different types of equipment used. PMID:27452261

Comparison of digital tomosynthesis and chest radiography for the detection of pulmonary nodules: systematic review and meta-analysis.

PubMed

Kim, Jun H; Lee, Kyung H; Kim, Kyoung-Tae; Kim, Hyun J; Ahn, Hyeong S; Kim, Yeo J; Lee, Ha Y; Jeon, Yong S

2016-12-01

To compare the diagnostic accuracy of digital tomosynthesis (DTS) with that of chest radiography for the detection of pulmonary nodules by meta-analysis. A systematic literature search was performed to identify relevant original studies from 1 January 1 1976 to 31 August 31 2016. The quality of included studies was assessed by quality assessment of diagnostic accuracy studies-2. Per-patient data were used to calculate the sensitivity and specificity and per-lesion data were used to calculate the detection rate. Summary receiver-operating characteristic curves were drawn for pulmonary nodule detection. 16 studies met the inclusion criteria. 1017 patients on a per-patient basis and 2159 lesions on a per-lesion basis from 16 eligible studies were evaluated. The pooled patient-based sensitivity of DTS was 0.85 [95% confidence interval (CI) 0.83-0.88] and the specificity was 0.95 (0.93-0.96). The pooled sensitivity and specificity of chest radiography were 0.47 (0.44-0.51) and 0.37 (0.34-0.40), respectively. The per-lesion detection rate was 2.90 (95% CI 2.63-3.19). DTS has higher diagnostic accuracy than chest radiography for detection of pulmonary nodules. Chest radiography has low sensitivity but similar specificity, comparable with that of DTS. Advances in knowledge: DTS has higher diagnostic accuracy than chest radiography for the detection of pulmonary nodules.

Comparing diagnostic accuracy of bedside ultrasound and radiography for bone fracture screening in multiple trauma patients at the ED.

PubMed

Bolandparvaz, Shahram; Moharamzadeh, Payman; Jamali, Kazem; Pouraghaei, Mahboob; Fadaie, Maryam; Sefidbakht, Sepideh; Shahsavari, Kavous

2013-11-01

Long bone fractures are currently diagnosed using radiography, but radiography has some disadvantages (radiation and being time consuming). The present study compared the diagnostic accuracy of bedside ultrasound and radiography in multiple trauma patients at the emergency department (ED). The study assessed 80 injured patients with multiple trauma from February 2011 to July 2012. The patients were older than 18 years and triaged to the cardiopulmonary resuscitation ward of the ED. Bedside ultrasound and radiography were conducted for them. The findings were separately and blindly assessed by 2 radiologists. Sensitivity, specificity, the positive and negative predictive value, and κ coefficient were measured to assess the accuracy and validity of ultrasound as compared with radiography. The sensitivity of ultrasound for diagnosis of limb bone fractures was not high enough and ranged between 55% and 75% depending on the fracture site. The specificity of this diagnostic method had an acceptable range of 62% to 84%. Ultrasound negative prediction value was higher than other indices under study and ranged between 73% and 83%, but its positive prediction value varied between 33.3% and 71%. The κ coefficient for diagnosis of long bone fractures of upper limb (κ = 0.58) and upper limb joints (κ = 0.47) and long bones of lower limb (κ = 0.52) was within the medium range. However, the value for diagnosing fractures of lower limb joints (κ = 0.47) was relatively low. Bedside ultrasound is not a reliable method for diagnosing fractures of upper and lower limb bones compared with radiography. © 2013 Elsevier Inc. All rights reserved.

Contrast-detail curves in chest radiography

NASA Astrophysics Data System (ADS)

Ogden, Kent; Scalzetti, Ernest; Huda, Walter; Saluja, Jasjeet; Lavallee, Robert

2005-04-01

We investigated how size and lesion location affect detection of simulated mass lesions in chest radiography. Simulated lesions were added to the center of 10 cm x 10 cm regions of digital chest radiographs, and used in 4-Alternative Forced-Choice (4-AFC) experiments. We determined the lesion contrast required to achieve a 92% correct detection rate I(92%). The mass size was manipulated to range from 1 to 10 mm, and we investigated lesion detection in the lung apex, hilar region, and in the sub-diaphragmatic region. In these experiments, the observer obtained I(92%) from randomized repeats obtained at each of seven lesion sizes, with the results plotted as I(92%) versus lesion size. In addition we investigated the effect of using the same background in the four 4-AFC experiments (twinned) and random backgrounds from the same anatomical region taken from 20 different radiographs. In all three anatomical regions investigated, the slopes of the contrast detail curve for the random background experiments were negative for lesion sizes less than 2.5, 3.5, and 5.5 mm in the hilar (slope of -0.26), apex (slope of -0.54), and sub-diaphragmatic (slope of -0.53) regions, respectively. For lesion sizes greater than these, the slopes were 0.34, 0.23, and 0.40 in the hilar, apex, and sub-diaphragmatic regions, respectively. The positive slopes for portions of the contrast-detail curves in chest radiography are a result of the anatomical background, and show that larger lesions require more contrast for visualization.

Neutron Focusing Mirrors for Neutron Radiography of Irradiated Nuclear Fuel at Idaho National Laboratory

NASA Astrophysics Data System (ADS)

Rai, Durgesh K.; Wu, Huarui; Abir, Muhammad; Giglio, Jeffrey; Khaykovich, Boris

Post irradiation examination (PIE) of samples irradiated in nuclear reactors is a challenging but necessary task for the development on novel nuclear power reactors. Idaho National Laboratory (INL) has neutron radiography capabilities, which are especially useful for the PIE of irradiated nuclear fuel. These capabilities are limited due to the extremely high gamma-ray radiation from the irradiated fuel, which precludes the use of standard digital detectors, in turn limiting the ability to do tomography and driving the cost of the measurements. In addition, the small 250 kW Neutron Radiography Reactor (NRAD) provides a relatively weak neutron flux, which leads to low signal-to-noise ratio. In this work, we develop neutron focusing optics suitable for the installation at NRAD. The optics would separate the sample and the detector, potentially allowing for the use of digital radiography detectors, and would provide significant intensity enhancement as well. The optics consist of several coaxial nested Wolter mirrors and is suited for polychromatic thermal neutron radiation. Laboratory Directed Research and Development program of Idaho National Laboratory.

A cytogenetic biomonitoring of industrial radiographers occupationally exposed to low levels of ionizing radiation by using cbmn assay.

PubMed

Shakeri, Mahsa; Zakeri, Farideh; Changizi, Vahid; Rajabpour, Mohammad Reza; Farshidpour, Mohammad Reza

2017-06-15

Industrial radiography is the process of using either gamma-emitting radionuclide sources or X-ray machines to examine the safety of industrial materials. The average annual effective dose in industrial radiography is one of the highest among radiation workers. The aim of this study was to investigate the cytogenetic effects of ionizing radiation in the peripheral blood lymphocytes of 60 industrial radiographers and 40 non-exposed individuals as the control group by using cytokinesis-block micronucleus (CBMN) assay. Totally, the frequencies of micronuclei (MN), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) were significantly higher in the industrial radiographers than in the controls (p = 0.000). The mean MN frequency per 1000 binucleated cells in the industrial radiographers with last 5-y radiation dose of >100 mSv was significantly higher than those with ≤100 mSv (34.81 ± 12.7‰ vs. 26.33 ± 7.94‰, p = 0.024). The effect of age was observed in the control group and subjects with the age of >30 y showed significantly higher MN frequency compared with the subjects with the age of ≤30 y (9.45 ± 3.71‰ vs. 6.81 ± 3.05‰, p = 0.02). No obvious trend of increased MN as a function of either duration of employment or age or smoking status was observed in the industrial radiographers. The results show the increased levels of cytogenetic damages in the industrial radiographers. Even the workers exposed to the permissible doses are subjected to elevated frequencies of DNA damages. These findings confirm the importance of cytogenetic biomonitoring program beside physical dosimetry, surveying radiation safety of equipment and periodic training of workers for improvement of safety and radiation protection. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Anatomical variations of mandibular canal detected by panoramic radiography and CT: a systematic review and meta-analysis

PubMed Central

Dutra, Kamile; Porporatti, André Luís; Mezzomo, Luis A; De Luca Canto, Graziela; Flores-Mir, Carlos; Corrêa, Márcio

2016-01-01

Objectives: To investigate the anatomical variations of the mandibular canal through assessment in situ, panoramic radiography, CT or CBCT and assess their frequency. Methods: Articles were selected from databases (Cochrane Library, LILACS, ProQuest, PubMed, Scopus, Web of Science and Google Scholar), articles without limitations of language, in which the main objective was to evaluate the frequency of bifurcation of the mandibular canal through assessment in situ, panoramic radiography, CT or CBCT were selected. A meta-analysis of prevalence using random effects was performed. Results: Using a selection process in two phases, 15 articles were identified, and a meta-analysis was conducted. The results from these meta-analyses showed that the overall prevalence of anatomical variations for in situ studies was 6.46%, and through assessment of panoramic radiography and CT or CBCT the overall prevalence shown was 4.20% and 16.25%, respectively. Conclusions: There are two types of variations of the mandibular canal: the retromolar canal and bifid mandibular canal. The frequency variations through assessing in situ, panoramic radiography and CT or CBCT were 6.46%, 4.20% and 16.25%, respectively. PMID:26576624

Utility of a Newly Designed Film Holder for Premolar Bitewing Radiography.

PubMed

Safi, Yaser; Esmaeelinejad, Mohammad; Vasegh, Zahra; Valizadeh, Solmaz; Aghdasi, Mohammad Mehdi; Sarani, Omid; Afsahi, Mahmoud

2015-11-01

Bitewing radiography is a valuable technique for assessment of proximal caries, alveolar crest and periodontal status. Technical errors during radiography result in erroneous radiographic interpretation, misdiagnosis, possible mistreatment or unnecessary exposure of patient for taking a repeat radiograph. In this study, we aimed to evaluate the efficacy of a film holder modified from the conventional one and compared it with that of conventional film holder. Our study population comprised of 70 patients who were referred to the Radiology Department for bilateral premolar bitewing radiographs as requested by their attending clinician. Bitewing radiographs in each patient were taken using the newly designed holder in one side and the conventional holder in the other side. The acceptability of the two holders from the perspectives of the technician and patients was determined using a 0-20 point scale. The frequency of overlap and film positioning errors was calculated for each method. The conventional holder had greater acceptability among patients compared to the newly designed holder (mean score of 16.59 versus 13.37). From the technicians' point of view, the newly designed holder was superior to the conventional holder (mean score of 17.33 versus 16.44). The frequency of overlap was lower using the newly designed holder (p<0.001) and it allowed more accurate film positioning (p=0.005). The newly designed holder may facilitate the process of radiography for technicians and may be associated with less frequency of radiographic errors compared to the conventional holder.

Influence of lead apron shielding on absorbed doses from panoramic radiography.

PubMed

Rottke, D; Grossekettler, L; Sawada, K; Poxleitner, P; Schulze, D

2013-01-01

This study investigated the absorbed doses in a full anthropomorphic body phantom from two different panoramic radiography devices, performing protocols with and without applying a lead apron. A RANDO(®) full body phantom (Alderson Research Laboratories Inc., Stamford, CT) was equipped with 110 thermoluminescent dosemeters at 55 different sites and set up in two different panoramic radiography devices [SCANORA(®) three-dimensional (3D) (SOREDEX, Tuusula, Finland) and ProMax(®) 3D (Planmeca, Helsinki, Finland)] and exposed. Two different protocols were performed in the two devices. The first protocol was performed without any lead shielding, whereas the phantom was equipped with a standard adult lead apron for the second protocol. A two-tailed paired samples t-test for the SCANORA 3D revealed that there is no difference between the protocol using lead apron shielding (m = 87.99, s = 102.98) and the protocol without shielding (m = 87.34, s = 107.49), t(54) = -0.313, p > 0.05. The same test for the ProMax 3D showed that there is also no difference between the protocol using shielding (m = 106.48, s = 117.38) and the protocol without shielding (m = 107.75, s = 114,36), t(54) = 0.938, p > 0.05. In conclusion, the results of this study showed no statistically significant differences between a panoramic radiography with or without the use of lead apron shielding.

Influence of lead apron shielding on absorbed doses from panoramic radiography.

PubMed

Rottke, D; Grossekettler, L; Sawada, K; Poxleitner, P; Schulze, D

2013-01-01

This study investigated the absorbed doses in a full anthropomorphic body phantom from two different panoramic radiography devices, performing protocols with and without applying a lead apron. A RANDO® full body phantom (Alderson Research Laboratories Inc., Stamford, CT) was equipped with 110 thermoluminescent dosemeters at 55 different sites and set up in two different panoramic radiography devices [SCANORA® three-dimensional (3D) (SOREDEX, Tuusula, Finland) and ProMax® 3D (Planmeca, Helsinki, Finland)] and exposed. Two different protocols were performed in the two devices. The first protocol was performed without any lead shielding, whereas the phantom was equipped with a standard adult lead apron for the second protocol. A two-tailed paired samples t-test for the SCANORA 3D revealed that there is no difference between the protocol using lead apron shielding (m = 87.99, s = 102.98) and the protocol without shielding (m = 87.34, s = 107.49), t(54) = −0.313, p > 0.05. The same test for the ProMax 3D showed that there is also no difference between the protocol using shielding (m = 106.48, s = 117.38) and the protocol without shielding (m = 107.75, s = 114,36), t(54) = 0.938, p > 0.05. In conclusion, the results of this study showed no statistically significant differences between a panoramic radiography with or without the use of lead apron shielding.

Imaging Brunelleschi's cupola wall using muon scattering radiography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guardincerri, Elena

2015-09-16

This PowerPoint presentation describes the cupola's structure and current reinforcements, reasoning behind why muon radiography would be helpful. A demonstration project is described where a similar wall was constructed to illustrate the potential benefits to Italian authorities; Requirements and a potential plan were created and collaboration to make it happen was deemed to be possible among LANL, Toshiba, the Parma and Florence Universities and the Opera del Duomo,

Portable radiography: a reality and necessity for ISS and explorer-class missions.

PubMed

Lerner, David J; Parmet, Allen J

2015-02-01

On ISS missions and explorer class missions, unexpected medical and surgical emergencies could be disastrous. Lack of ability to rapidly assess and make critical decisions affects mission capability. Current imaging modalities on ISS consist only of ultrasound. There are many acute diagnoses which ultrasound alone cannot diagnose. Portable X-Ray imaging (radiography) technology has advanced far enough to where it is now small enough, cheap enough, and accurate enough to give diagnostic quality images sent wirelessly to the onboard computer and on Earth for interpretation while fitting in something the size of a briefcase. Although further research is warranted, Portable Radiography is an important addition to have on ISS and future Explorer Class Missions while maintaining a very small footprint.

Combining Radiography and Passive Measurements for Radiological Threat Detection in Cargo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, Erin A.; White, Timothy A.; Jarman, Kenneth D.

Abstract Radiography is widely understood to provide information complimentary to passive detection: while not directly sensitive to radiological materials, radiography can reveal highly shielded regions which may mask a passive radiological signal. We present a method for combining radiographic and passive data which uses the radiograph to provide an estimate of scatter and attenuation for possible sources. This approach allows quantitative use of radiographic images without relying on image interpretation, and results in a probabilistic description of likely source locations and strengths. We present first results for this method for a simple modeled test case of a cargo container drivingmore » through a PVT portal. With this inversion approach, we address criteria for an integrated passive and radiographic screening system and how detection of SNM threats might be improved in such a system.« less

Measurement of Coolant in a Flat Heat Pipe Using Neutron Radiography

NASA Astrophysics Data System (ADS)

Mizuta, Kei; Saito, Yasushi; Goshima, Takashi; Tsutsui, Toshio

A newly developed flat heat pipe FGHPTM (Morex Kiire Co.) was experimentally investigated by using neutron radiography. The test sample of the FGHP heat spreader was 65 × 65 × 2 mm3 composed of several etched copper plates and pure water was used as the coolant. Neutron radiography was performed at the E-2 port of the Kyoto University Research Reactor (KUR). The coolant distributions in the wick area of the FGHP and its heat transfer characteristics were measured at heating conditions. Experimental results show that the coolant distributions depend slightly on its installation posture and that the liquid thickness in the wick region remains constant with increasing heat input to the FGHP. In addition, it is found that the wick surface does not dry out even in the vertical posture at present experimental conditions.

Factors affecting general practitioners' decisions about plain radiography for back pain: implications for classification of guideline barriers – a qualitative study

PubMed Central

Espeland, Ansgar; Baerheim, Anders

2003-01-01

Background General practitioners often diverge from clinical guidelines regarding spine radiography. This study aimed to identify and describe A) factors general practitioners consider may affect their decisions about ordering plain radiography for back pain and B) barriers to guideline adherence suggested by such factors. Methods Focus group interviews regarding factors affecting ordering decisions were carried out on a diverse sample of Norwegian general practitioners and were analysed qualitatively. Results of this study and two qualitative studies from the Netherlands and USA on use of spine radiography were interpreted for barriers to guideline adherence. These were compared with an existing barrier classification system described by Dr Cabana's group. Results The factors which Norwegian general practitioners considered might affect their decisions about ordering plain radiography for back pain concerned the following broader issues: clinical ordering criteria, patients' wishes for radiography and the general practitioner's response, uncertainty, professional dignity, access to radiology services, perception of whether the patient really was ill, sense of pressure from other health care providers/social security, and expectations about the consequences of ordering radiography. The three studies suggested several attitude-related and external barriers as classified in a previously reported system described by Dr Cabana in another study. Identified barriers not listed in this system were: lack of expectancy that guideline adherence will lead to desired health care process, emotional difficulty with adherence, improper access to actual/alternative health care services, and pressure from health care providers/organisations. Conclusions Our findings may help implement spine radiography guidelines. They also indicate that Cabana et al.'s barrier classification system needs extending. A revised system is proposed. PMID:12659640

Comparison of radiography and ultrasonography for diagnosing small-intestinal mechanical obstruction in vomiting dogs.

PubMed

Sharma, Ajay; Thompson, Margret S; Scrivani, Peter V; Dykes, Nathan L; Yeager, Amy E; Freer, Sean R; Erb, Hollis N

2011-01-01

A cross-sectional study was performed on acutely vomiting dogs to compare the accuracy of radiography and ultrasonography for the diagnosis of small-intestinal mechanical obstruction and to describe several radiographic and ultrasonographic signs to identify their contribution to the final diagnosis. The sample population consisted of 82 adult dogs and small-intestinal obstruction by foreign body was confirmed in 27/82 (33%) dogs by surgery or necropsy. Radiography produced a definitive result (obstructed or not obstructed) in 58/82 (70%) of dogs; ultrasonography produced a definitive result in 80/82 (97%) of dogs. On radiographs, a diagnosis of obstruction was based on detection of segmental small-intestinal dilatation, plication, or detection of a foreign body. Approximately 30% (8/27) of obstructed dogs did not have radiographic signs of segmental small-intestinal dilatation, of which 50% (4/8) were due to linear foreign bodies. The ultrasonographic diagnosis of small-intestinal obstruction was based on detection of an obstructive lesion, sonographic signs of plication or segmental, small-intestinal dilatation. The ultrasonographic presence or absence of moderate-to-severe intestinal diameter enlargement (due to lumen dilatation) of the jejunum (>1.5 cm) was a useful discriminatory finding and, when present, should prompt a thorough search for a cause of small-intestinal obstruction. In conclusion, both abdominal radiography and abdominal ultrasonography are accurate for diagnosing small-intestinal obstruction in vomiting dogs and either may be used depending on availability and examiner choice. Abdominal ultrasonography had greater accuracy, fewer equivocal results and provided greater diagnostic confidence compared with radiography. © 2010 Veterinary Radiology & Ultrasound.

Subtraction Radiography for the Diagnosis of Bone Lesions in Dogs.

DTIC Science & Technology

1984-05-31

Avail ander Journal of Periodontology Dist Special Ř 211 East Chicago Avenue Room 924 Chicago, IL 60611 Dear Sirs: I m submitting an original...research article titled "Subtraction Radiography for the Diagnosis of Bone Lesions in Dogs" solely to the Journal of Periodontology for review and

Clinical comparative study with a large-area amorphous silicon flat-panel detector: image quality and visibility of anatomic structures on chest radiography.

PubMed

Fink, Christian; Hallscheidt, Peter J; Noeldge, Gerd; Kampschulte, Annette; Radeleff, Boris; Hosch, Waldemar P; Kauffmann, Günter W; Hansmann, Jochen

2002-02-01

The objective of this study was to compare clinical chest radiographs of a large-area, flat-panel digital radiography system and a conventional film-screen radiography system. The comparison was based on an observer preference study of image quality and visibility of anatomic structures. Routine follow-up chest radiographs were obtained from 100 consecutive oncology patients using a large-area, amorphous silicon flat-panel detector digital radiography system (dose equivalent to a 400-speed film system). Hard-copy images were compared with previous examinations of the same individuals taken on a conventional film-screen system (200-speed). Patients were excluded if changes in the chest anatomy were detected or if the time interval between the examinations exceeded 1 year. Observer preference was evaluated for the image quality and the visibility of 15 anatomic structures using a five-point scale. Dose measurements with a chest phantom showed a dose reduction of approximately 50% with the digital radiography system compared with the film-screen radiography system. The image quality and the visibility of all but one anatomic structure of the images obtained with the digital flat-panel detector system were rated significantly superior (p < or = 0.0003) to those obtained with the conventional film-screen radiography system. The image quality and visibility of anatomic structures on the images obtained by the flat-panel detector system were perceived as equal or superior to the images from conventional film-screen chest radiography. This was true even though the radiation dose was reduced approximately 50% with the digital flat-panel detector system.

Multiple image x-radiography for functional lung imaging

NASA Astrophysics Data System (ADS)

Aulakh, G. K.; Mann, A.; Belev, G.; Wiebe, S.; Kuebler, W. M.; Singh, B.; Chapman, D.

2018-01-01

Detection and visualization of lung tissue structures is impaired by predominance of air. However, by using synchrotron x-rays, refraction of x-rays at the interface of tissue and air can be utilized to generate contrast which may in turn enable quantification of lung optical properties. We utilized multiple image radiography, a variant of diffraction enhanced imaging, at the Canadian light source to quantify changes in unique x-ray optical properties of lungs, namely attenuation, refraction and ultra small-angle scatter (USAXS or width) contrast ratios as a function of lung orientation in free-breathing or respiratory-gated mice before and after intra-nasal bacterial endotoxin (lipopolysaccharide) instillation. The lung ultra small-angle scatter and attenuation contrast ratios were significantly higher 9 h post lipopolysaccharide instillation compared to saline treatment whereas the refraction contrast decreased in magnitude. In ventilated mice, end-expiratory pressures result in an increase in ultra small-angle scatter contrast ratio when compared to end-inspiratory pressures. There were no detectable changes in lung attenuation or refraction contrast ratio with change in lung pressure alone. In effect, multiple image radiography can be applied towards following optical properties of lung air-tissue barrier over time during pathologies such as acute lung injury.

Comparison of digital tomosynthesis and chest radiography for the detection of pulmonary nodules: systematic review and meta-analysis

PubMed Central

Kim, Jun H; Lee, Kyung H; Kim, Kyoung-Tae; Ahn, Hyeong S; Kim, Yeo J; Lee, Ha Y; Jeon, Yong S

2016-01-01

Objective: To compare the diagnostic accuracy of digital tomosynthesis (DTS) with that of chest radiography for the detection of pulmonary nodules by meta-analysis. Methods: A systematic literature search was performed to identify relevant original studies from 1 January 1 1976 to 31 August 31 2016. The quality of included studies was assessed by quality assessment of diagnostic accuracy studies-2. Per-patient data were used to calculate the sensitivity and specificity and per-lesion data were used to calculate the detection rate. Summary receiver-operating characteristic curves were drawn for pulmonary nodule detection. Results: 16 studies met the inclusion criteria. 1017 patients on a per-patient basis and 2159 lesions on a per-lesion basis from 16 eligible studies were evaluated. The pooled patient-based sensitivity of DTS was 0.85 [95% confidence interval (CI) 0.83–0.88] and the specificity was 0.95 (0.93–0.96). The pooled sensitivity and specificity of chest radiography were 0.47 (0.44–0.51) and 0.37 (0.34–0.40), respectively. The per-lesion detection rate was 2.90 (95% CI 2.63–3.19). Conclusion: DTS has higher diagnostic accuracy than chest radiography for detection of pulmonary nodules. Chest radiography has low sensitivity but similar specificity, comparable with that of DTS. Advances in knowledge: DTS has higher diagnostic accuracy than chest radiography for the detection of pulmonary nodules. PMID:27759428

Prevalence of ligamentum arteriosum calcification on multi-section spiral CT and digital radiography.

PubMed

Hong, Gil-Sun; Goo, Hyun Woo; Song, Jae-Woo

2012-06-01

To investigate the prevalence of ligamentum arteriosum calcification (LAC) on multi-section spiral CT and digital radiography. Five hundred and eight children and 232 adults who performed multi-section chest CT were included in this study and were divided into nine age groups: A (0-5 years), B (6-10 years), C (11-15 years), D (16-20 years), E (21-30 years), F (31-40 years), G (41-50 years), H (51-60 years), and I (61-70 years). Two radiologists assessed the presence of LAC on axial and coronal CT images, defined as focal calcific density on both or on one plane with attenuation >100 Hounsfield unit. The prevalence of LAC on CT was compared between children and adults, and between unenhanced and enhanced CT in children. The prevalence of LAC on digital radiography was evaluated in 476 children. The prevalence of definite LAC on unenhanced multi-section CT was significantly higher in children (37.8 %) than in adults (11.2 %) (P < 0.001), with prevalences in groups: A through I of 35.8, 48.7, 35.1, 28.6, 25.0, 10.2, 15.5, 7.8, and 5.6 %, respectively. The prevalences of indeterminate LAC in age groups A-I on unenhanced multi-section CT were 4.5, 12.8, 8.1, 19.0, 0.0, 0.0, 0.0, 2.0, and 1.9 %. In children, the prevalence of LAC was significantly higher on unenhanced than on enhanced CT (37.8 vs. 16.4 %, P < 0.001). The prevalence of LAC on digital radiography was 3.6 % in children. LAC is frequently observed in children and adults on multi-section spiral CT, more frequently than previously reported. Compared with that on multi-section spiral CT, the prevalence of LAC on digital radiography is substantially low.

Flash X-Ray Apparatus With Spectrum Control Functions For Medical Use And Fuji Computed Radiography

NASA Astrophysics Data System (ADS)

Isobe, H.; Sato, E.; Hayasi, Y.; Suzuki, M.; Arima, H.; Hoshino, F.

1985-02-01

Flash radiographic bio-medical studies at sub-microsecond intervals were performed by using both a new type of flash X-ray(FX) apparatus with spectrum control functions and Fuji Computed Radiography(FCR). This single flasher tends to have a comparatively long exposure time and the electric pulse width of the FX wave form is about 0.3,usec. The maximum FX dose is about 50mR at 1m per pulse, and the effective focal spot varies according to condenser charging voltage, A-C distance, etc., ranging from 1.0 to 3.0mm in diameter, but in the low dose rate region it can be reduced to less than 1.0mm in diameter. The FX dose is determined by the condenser charging voltage and the A-C distance, while the FX spectrum is determined by the average voltage of the FX tube and filters. Various clear FX images were obtained by controlling the spectrum and dose. FCR is a new storage medium for medical radiography developed by the Fuji Photo Film Co., Ltd. and this apparatus has various image forming functions: low dose radiography, film density control, image contrast control, subtraction management and others. We have used this new apparatus in conjunction with our FX radiography and have obtained some new and interesting biomedical radiograms: the edge enhancement image, the instantaneous enlarged image, and the single exposure energy subtraction image using the FX spectrum distribution.

New Developments in Proton Radiography at the Los Alamos Neutron Science Center (LANSCE)

DOE PAGES

Morris, C. L.; Brown, E. N.; Agee, C.; ...

2015-12-30

An application of nuclear physics, a facility for using protons for flash radiography, was developed at the Los Alamos Neutron Science Center (LANSCE). Protons have proven far superior to high energy x-rays for flash radiography because of their long mean free path, good position resolution, and low scatter background. Although this facility is primarily used for studying very fast phenomena such as high explosive driven experiments, it is finding increasing application to other fields, such as tomography of static objects, phase changes in materials and the dynamics of chemical reactions. The advantages of protons are discussed, data from some recentmore » experiments will be reviewed and concepts for new techniques are introduced.« less

Corrections on energy spectrum and scatterings for fast neutron radiography at NECTAR facility

NASA Astrophysics Data System (ADS)

Liu, Shu-Quan; Bücherl, Thomas; Li, Hang; Zou, Yu-Bin; Lu, Yuan-Rong; Guo, Zhi-Yu

2013-11-01

Distortions caused by the neutron spectrum and scattered neutrons are major problems in fast neutron radiography and should be considered for improving the image quality. This paper puts emphasis on the removal of these image distortions and deviations for fast neutron radiography performed at the NECTAR facility of the research reactor FRM- II in Technische Universität München (TUM), Germany. The NECTAR energy spectrum is analyzed and established to modify the influence caused by the neutron spectrum, and the Point Scattered Function (PScF) simulated by the Monte-Carlo program MCNPX is used to evaluate scattering effects from the object and improve image quality. Good analysis results prove the sound effects of the above two corrections.

Proton radiography for inline treatment planning and positioning verification of small animals.

PubMed

Müller, Johannes; Neubert, Christian; von Neubeck, Cläre; Baumann, Michael; Krause, Mechthild; Enghardt, Wolfgang; Bütof, Rebecca; Dietrich, Antje; Lühr, Armin

2017-11-01

As proton therapy becomes increasingly well established, there is a need for high-quality clinically relevant in vivo data to gain better insight into the radiobiological effects of proton irradiation on both healthy and tumor tissue. This requires the development of easily applicable setups that allow for efficient, fractionated, image-guided proton irradiation of small animals, the most widely used pre-clinical model. Here, a method is proposed to perform dual-energy proton radiography for inline positioning verification and treatment planning. Dual-energy proton radiography exploits the differential enhancement of object features in two successively measured two-dimensional (2D) dose distributions at two different proton energies. The two raw images show structures that are dominated by energy absorption (absorption mode) or scattering (scattering mode) of protons in the object, respectively. Data post-processing allowed for the separation of both signal contributions in the respective images. The images were evaluated regarding recognizable object details and feasibility of rigid registration to acquired planar X-ray scans. Robust, automated rigid registration of proton radiography and planar X-ray images in scattering mode could be reliably achieved with the animal bedding unit used as registration landmark. Distinguishable external and internal features of the imaged mouse included the outer body contour, the skull with substructures, the lung, abdominal structures and the hind legs. Image analysis based on the combined information of both imaging modes allowed image enhancement and calculation of 2D water-equivalent path length (WEPL) maps of the object along the beam direction. Fractionated irradiation of exposed target volumes (e.g., subcutaneous tumor model or brain) can be realized with the suggested method being used for daily positioning and range determination. Robust registration of X-ray and proton radiography images allows for the irradiation of

A computerized scheme for lung nodule detection in multiprojection chest radiography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo Wei; Li Qiang; Boyce, Sarah J.

2012-04-15

Purpose: Our previous study indicated that multiprojection chest radiography could significantly improve radiologists' performance for lung nodule detection in clinical practice. In this study, the authors further verify that multiprojection chest radiography can greatly improve the performance of a computer-aided diagnostic (CAD) scheme. Methods: Our database consisted of 59 subjects, including 43 subjects with 45 nodules and 16 subjects without nodules. The 45 nodules included 7 real and 38 simulated ones. The authors developed a conventional CAD scheme and a new fusion CAD scheme to detect lung nodules. The conventional CAD scheme consisted of four steps for (1) identification ofmore » initial nodule candidates inside lungs, (2) nodule candidate segmentation based on dynamic programming, (3) extraction of 33 features from nodule candidates, and (4) false positive reduction using a piecewise linear classifier. The conventional CAD scheme processed each of the three projection images of a subject independently and discarded the correlation information between the three images. The fusion CAD scheme included the four steps in the conventional CAD scheme and two additional steps for (5) registration of all candidates in the three images of a subject, and (6) integration of correlation information between the registered candidates in the three images. The integration step retained all candidates detected at least twice in the three images of a subject and removed those detected only once in the three images as false positives. A leave-one-subject-out testing method was used for evaluation of the performance levels of the two CAD schemes. Results: At the sensitivities of 70%, 65%, and 60%, our conventional CAD scheme reported 14.7, 11.3, and 8.6 false positives per image, respectively, whereas our fusion CAD scheme reported 3.9, 1.9, and 1.2 false positives per image, and 5.5, 2.8, and 1.7 false positives per patient, respectively. The low performance of the

Location of the Central Venous Catheter Tip With Bedside Ultrasound in Young Children: Can We Eliminate the Need for Chest Radiography?

PubMed

Alonso-Quintela, Paula; Oulego-Erroz, Ignacio; Rodriguez-Blanco, Silvia; Muñiz-Fontan, Manoel; Lapeña-López-de Armentia, Santiago; Rodriguez-Nuñez, Antonio

2015-11-01

To compare the use of bedside ultrasound and chest radiography to verify central venous catheter tip positioning. Prospective observational study. PICU of a university hospital. Patients aged 0-14 who required a central venous catheter. None. Central venous catheter tip location was confirmed by ultrasound and chest radiography. Central venous catheters were classified as intra-atrial or extra-atrial according to their positions in relation to the cavoatrial junction. Central venous catheters located outside the vena cava were considered malpositioned. The distance between the catheter tip and the cavoatrial junction was measured. The time elapsed from image capture to interpretation was recorded. Fifty-one central venous catheters in 40 patients were analyzed. Chest radiography and ultrasound results agreed 94% of the time (κ coefficient, 0.638; p < 0.001) in determining intra-atrial and extra-atrial locations and 92% of the time in determining the diagnosis of central venous catheter malposition (κ coefficient, 0.670; p < 0.001). Chest radiography indicated a greater distance between the central venous catheter tip and the cavoatrial junction than measured by ultrasound, with a mean difference of 0.38 cm (95% CI, +0.27, +0.48 cm). Three central venous catheters were classified as extra-atrial by chest radiography but as intra-atrial by ultrasound. To locate the central venous catheter tip, ultrasound required less time than chest radiography (22.96 min [20.43 min] vs 2.23 min [1.06 min]; p < 0.001). Bedside ultrasound showed a good agreement with chest radiography in detecting central venous catheter tip location and revealing incorrect positions. Ultrasound could be a preferable method for routine verification of central venous catheter tip and can contribute to increased patient safety.

SU-E-I-15: Comparison of Radiation Dose for Radiography and EOS in Adolescent Scoliosis Patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schueler, B; Walz-Flannigan, A

Purpose: To estimate patient radiation dose for whole spine imaging using EOS, a new biplanar slot-scanning radiographic system and compare with standard scoliosis radiography. Methods: The EOS imaging system (EOS Imaging, Paris, France) consists of two orthogonal x-ray fan beams which simultaneously acquire frontal and lateral projection images of a standing patient. The patient entrance skin air kerma was measured for each projection image using manufacturer-recommended exposure parameters for spine imaging. Organ and effective doses were estimated using a commercially-available Monte Carlo simulation program (PCXMC, STUK, Radiation and Nuclear Safety Authority, Helsinki, Finland) for a 15 year old mathematical phantommore » model. These results were compared to organ and effective dose estimated for scoliosis radiography using computed radiography (CR) with standard exposure parameters obtained from a survey of pediatric radiographic projections. Results: The entrance skin air kerma for EOS was found to be 0.18 mGy and 0.33 mGy for posterior-anterior (PA) and lateral projections, respectively. This compares to 0.76 mGy and 1.4 mGy for CR, PA and lateral projections. Effective dose for EOS (PA and lateral projections combined) is 0.19 mSv compared to 0.51 mSv for CR. Conclusion: The EOS slot-scanning radiographic system allows for reduced patient radiation dose in scoliosis patients as compared to standard CR radiography.« less

Intense X-ray machine for penetrating radiography

NASA Astrophysics Data System (ADS)

Lucht, Roy A.; Eckhouse, Shimon

Penetrating radiography has been used for many years in the nuclear weapons research programs. Infrequently penetrating radiography has been used in conventional weapons research programs. For example the Los Alamos PHERMEX machine was used to view uranium rods penetrating steel for the GAU-8 program, and the Ector machine was used to see low density regions in forming metal jets. The armor/anti-armor program at Los Alamos has created a need for an intense flash X-ray machine that can be dedicated to conventional weapons research. The Balanced Technology Initiative, through DARPA, has funded the design and construction of such a machine at Los Alamos. It will be an 8- to 10-MeV diode machine capable of delivering a dose of 500 R at 1 m with a spot size of less than 5 mm. The machine used an 87.5-stage low inductance Marx generator that charges up a 7.4-(Omega), 32-ns water line. The water line is discharged through a self-breakdown oil switch into a 12.4-(Omega) water line that rings up the voltage into the high impendance X-ray diode. A long (233-cm) vacuum drift tube is used to separate the large diameter oil-insulated diode region from the X-ray source area that may be exposed to high overpressures by the explosive experiments. The electron beam is selffocused at the target area using a low pressure background gas.

Flash Kα radiography of laser-driven solid sphere compression for fast ignition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sawada, H.; Lee, S.; Shiroto, T.

2016-06-20

Time-resolved compression of a laser-driven solid deuterated plastic sphere with a cone was measured with flash Kα x-ray radiography. A spherically converging shockwave launched by nanosecond GEKKO XII beams was used for compression while a flash of 4.51 keV Ti Kα x-ray backlighter was produced by a high-intensity, picosecond laser LFEX (Laser for Fast ignition EXperiment) near peak compression for radiography. Areal densities of the compressed core were inferred from two-dimensional backlit x-ray images recorded with a narrow-band spherical crystal imager. The maximum areal density in the experiment was estimated to be 87 ± 26 mg/cm 2. Lastly, the temporalmore » evolution of the experimental and simulated areal densities with a 2-D radiation-hydrodynamics code is in good agreement.« less

[Digital radiography in young children. Considerations based on experiences in practice].

PubMed

Berkhout, W E R; Mileman, P A; Weerheijm, K L

2004-10-01

In dentistry, digital radiology techniques, such as a charge-coupled device and a storage phosphor plate, are gaining popularity. It was the objective of this study to assess the importance of the advantages and disadvantages of digital radiology techniques for bitewing radiography in young children, when compared to conventional film. A group of dentists received a questionnaire regarding their experiences with digital radiology techniques or conventional films among young children. Using the Simple Multi-Attributive Rating Technique (SMART) a final weighted score was calculated for the charge-coupled device, the phosphor plate, and conventional film. The scores were 7.40, 7.38, and 6.98 respectively. The differences were not statistically significant (p > 0.47). It could be concluded that, on the basis of experiences in practice, there are no statistically significant preferences for the use of digital radioogy techniques for bitewing radiography in young children.

Image enhancement using MCNP5 code and MATLAB in neutron radiography.

PubMed

Tharwat, Montaser; Mohamed, Nader; Mongy, T

2014-07-01

This work presents a method that can be used to enhance the neutron radiography (NR) image for objects with high scattering materials like hydrogen, carbon and other light materials. This method used Monte Carlo code, MCNP5, to simulate the NR process and get the flux distribution for each pixel of the image and determines the scattered neutron distribution that caused image blur, and then uses MATLAB to subtract this scattered neutron distribution from the initial image to improve its quality. This work was performed before the commissioning of digital NR system in Jan. 2013. The MATLAB enhancement method is quite a good technique in the case of static based film neutron radiography, while in neutron imaging (NI) technique, image enhancement and quantitative measurement were efficient by using ImageJ software. The enhanced image quality and quantitative measurements were presented in this work. Copyright © 2014 Elsevier Ltd. All rights reserved.

Comparison of flat-panel digital to conventional film-screen radiography in detection of experimentally created lesions of the equine third metacarpal bone.

PubMed

Moorman, Valerie J; Marshall, John F; Devine, Dustin V; Payton, Mark; Jann, Henry W; Bahr, Robert

2009-01-01

Radiographic diagnosis of equine bone disease using digital radiography is prevalent in veterinary practice. However, the diagnostic quality of digital vs. conventional radiography has not been compared systematically. We hypothesized that digital radiography would be superior to film-screen radiography for detection of subtle lesions of the equine third metacarpal bone. Twenty-four third metacarpal bones were collected from horses euthanized for reasons other than orthopedic disease. Bones were dissected free of soft tissue and computed tomography was performed to ensure that no osseous abnormalities were present. Subtle osseous lesions were produced in the dorsal cortex of the third metacarpal bones, and the bones were radiographed in a soft tissue phantom using indirect digital and conventional radiography at standard exposures. Digital radiographs were printed onto film. Three Diplomates of the American College of Veterinary Radiology evaluated the radiographs for the presence or absence of a lesion. Receiver operator characteristic curves were constructed, and the area under these curves were compared to assess the ability of the digital and film-screen radiographic systems to detect lesions. The area under the ROC curves for film-screen and digital radiography were 0.87 and 0.90, respectively (P = 0.59). We concluded that the digital radiographic system was comparable to the film-screen system for detection of subtle lesions of the equine third metacarpal bone.

COMPARISON OF THORACIC ULTRASONOGRAPHY AND RADIOGRAPHY FOR THE DETECTION OF INDUCED SMALL VOLUME PNEUMOTHORAX IN THE HORSE.

PubMed

Partlow, Jessica; David, Florent; Hunt, Luanne Michelle; Relave, Fabien; Blond, Laurent; Pinilla, Manuel; Lavoie, Jean-Pierre

2017-05-01

Small volume pneumothorax can be challenging to diagnose in horses. The current standard method for diagnosis is standing thoracic radiography. We hypothesized that thoracic ultrasonography would be more sensitive. Objectives of this prospective, experimental study were to describe a thoracic ultrasound method for detection of small volume pneumothorax in horses and to compare results of radiography and ultrasound in a sample of horses with induced small volume pneumothorax. Six mature healthy horses were recruited for this study. For each horse, five 50 ml air boluses were sequentially introduced via a teat cannula into the pleural space. Lateral thoracic radiographs and standardized ultrasound (2D and M-mode) examinations of both hemithoraces were performed following administration of each 50 ml air bolus. Radiographs and ultrasound images/videos were analyzed for detection of pneumothorax by four independent investigators who were unaware of treatment status. Sensitivity, specificity, positive predictive values, negative predictive values, and agreement among investigators (Kappa test, κ) were calculated for radiography, 2D and M-mode ultrasound. Comparisons were made using a chi-squared exact test with significance set at P < 0.05. Two-dimensional (84%) and M-mode (80%) ultrasound were more sensitive than radiography (48%) for pneumothorax detection (P = 0.02 and P = 0.04, respectively). Specificity and positive predictive values were similar for all three imaging modalities (P = 1). Agreement between investigators for pneumothorax detection was excellent for 2D ultrasound (κ = 1), very good for M-mode ultrasound (κ = 0.87), and good for radiography (κ = 0.79). Findings from this experimental study supported the use of thoracic ultrasonography as a diagnostic method for detecting pneumothorax in horses. © 2017 American College of Veterinary Radiology.

Evaluation of radiography as a screening method for detection and characterisation of congenital vertebral malformations in dogs.

PubMed

Brocal, Josep; De Decker, Steven; José-López, Roberto; Guevar, Julien; Ortega, Maria; Parkin, Tim; Ter Haar, Gert; Gutierrez-Quintana, Rodrigo

2018-05-19

Congenital vertebral malformations (CVM) are common in brachycephalic 'screw-tailed' dogs; they can be associated with neurological deficits and a genetic predisposition has been suggested. The purpose of this study was to evaluate radiography as a screening method for congenital thoracic vertebral malformations in brachycephalic 'screw-tailed' dogs by comparing it with CT. Forty-nine dogs that had both radiographic and CT evaluations of the thoracic vertebral column were included. Three observers retrospectively reviewed the images independently to detect CVMs. When identified, they were classified according to a previously published radiographic classification scheme. A CT consensus was then reached. All observers identified significantly more affected vertebrae when evaluating orthogonal radiographic views compared with lateral views alone; and more affected vertebrae with the CT consensus compared with orthogonal radiographic views. Given the high number of CVMs per dog, the number of dogs classified as being CVM free was not significantly different between CT and radiography. Significantly more midline closure defects were also identified with CT compared with radiography. Malformations classified as symmetrical or ventral hypoplasias on radiography were frequently classified as ventral and medial aplasias on CT images. Our results support that CT is better than radiography for the classification of CVMs and this will be important when further evidence of which are the most clinically relevant CVMs is identified. These findings are of particular importance for designing screening schemes of CVMs that could help selective breeding programmes based on phenotype and future studies. © British Veterinary Association (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Influence of lead apron shielding on absorbed doses from panoramic radiography

PubMed Central

Rottke, D; Grossekettler, L; Sawada, K; Poxleitner, P; Schulze, D

2013-01-01

Objectives: This study investigated the absorbed doses in a full anthropomorphic body phantom from two different panoramic radiography devices, performing protocols with and without applying a lead apron. Methods: A RANDO® full body phantom (Alderson Research Laboratories Inc., Stamford, CT) was equipped with 110 thermoluminescent dosemeters at 55 different sites and set up in two different panoramic radiography devices [SCANORA® three-dimensional (3D) (SOREDEX, Tuusula, Finland) and ProMax® 3D (Planmeca, Helsinki, Finland)] and exposed. Two different protocols were performed in the two devices. The first protocol was performed without any lead shielding, whereas the phantom was equipped with a standard adult lead apron for the second protocol. Results: A two-tailed paired samples t-test for the SCANORA 3D revealed that there is no difference between the protocol using lead apron shielding (m = 87.99, s = 102.98) and the protocol without shielding (m = 87.34, s = 107.49), t(54) = −0.313, p > 0.05. The same test for the ProMax 3D showed that there is also no difference between the protocol using shielding (m = 106.48, s = 117.38) and the protocol without shielding (m = 107.75, s = 114,36), t(54) = 0.938, p > 0.05. Conclusions: In conclusion, the results of this study showed no statistically significant differences between a panoramic radiography with or without the use of lead apron shielding. PMID:24174012

Real-time radiography support for Titan LAM

NASA Astrophysics Data System (ADS)

Anderson, M. G.

1992-07-01

This paper discusses real-time radiography (RTR) support for the Titan Lightweight Analog Motor (LAM) cold gas tests. RTR was used as a diagnostic technique to measure propellant deformation within the motors as gaseous nitrogen, at various pressures, was flowed over the propellant grain. The data consisted of video images that correlated the propellant deformation to time and to chamber pressure. Measurements were made on three propellant configurations in 17 tests. Specific issues addressed include the approach taken to gather the data, the system layout, and image processing techniques used to interpret the data.

Monochromatic x-ray radiography for areal-density measurement of inertial fusion energy fuel in fast ignition experiment.

PubMed

Fujioka, Shinsuke; Fujiwara, Takashi; Tanabe, Minoru; Nishimura, Hiroaki; Nagatomo, Hideo; Ohira, Shinji; Inubushi, Yuichi; Shiraga, Hiroyuki; Azechi, Hiroshi

2010-10-01

Ultrafast, two-dimensional x-ray imaging is an important diagnostics for the inertial fusion energy research, especially in investigating implosion dynamics at the final stage of the fuel compression. Although x-ray radiography was applied to observing the implosion dynamics, intense x-rays emitted from the high temperature and dense fuel core itself are often superimposed on the radiograph. This problem can be solved by coupling the x-ray radiography with monochromatic x-ray imaging technique. In the experiment, 2.8 or 5.2 keV backlight x-rays emitted from laser-irradiated polyvinyl chloride or vanadium foils were selectively imaged by spherically bent quartz crystals with discriminating the out-of-band emission from the fuel core. This x-ray radiography system achieved 24 μm and 100 ps of spatial and temporal resolutions, respectively.

Capsule Ablator Inflight Performance Measurements Via Streaked Radiography Of ICF Implosions On The NIF*

NASA Astrophysics Data System (ADS)

Dewald, E. L.; Tommasini, R.; Mackinnon, A.; MacPhee, A.; Meezan, N.; Olson, R.; Hicks, D.; LePape, S.; Izumi, N.; Fournier, K.; Barrios, M. A.; Ross, S.; Pak, A.; Döppner, T.; Kalantar, D.; Opachich, K.; Rygg, R.; Bradley, D.; Bell, P.; Hamza, A.; Dzenitis, B.; Landen, O. L.; MacGowan, B.; LaFortune, K.; Widmayer, C.; Van Wonterghem, B.; Kilkenny, J.; Edwards, M. J.; Atherton, J.; Moses, E. I.

2016-03-01

Streaked 1-dimensional (slit imaging) radiography of 1.1 mm radius capsules in ignition hohlraums was recently introduced on the National Ignition Facility (NIF) and gives an inflight continuous record of capsule ablator implosion velocities, shell thickness and remaining mass in the last 3-5 ns before peak implosion time. The high quality data delivers good accuracy in implosion metrics that meets our requirements for ignition and agrees with recently introduced 2-dimensional pinhole radiography. Calculations match measured trajectory across various capsule designs and laser drives when the peak laser power is reduced by 20%. Furthermore, calculations matching measured trajectories give also good agreement in ablator shell thickness and remaining mass.

A new clinical unit for digital radiography based on a thick amorphous selenium plate: physical and psychophysical characterization.

PubMed

Rivetti, Stefano; Lanconelli, Nico; Bertolini, Marco; Acchiappati, Domenico

2011-08-01

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

10 CFR 34.1 - Purpose and scope.

Code of Federal Regulations, 2013 CFR

2013-01-01

... REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL... issuance of licenses for the use of sealed sources containing byproduct material and radiation safety requirements for persons using these sealed sources in industrial radiography. The provisions and requirements...

10 CFR 34.1 - Purpose and scope.

Code of Federal Regulations, 2010 CFR

2010-01-01

... REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL... issuance of licenses for the use of sealed sources containing byproduct material and radiation safety requirements for persons using these sealed sources in industrial radiography. The provisions and requirements...

10 CFR 34.1 - Purpose and scope.

Code of Federal Regulations, 2011 CFR

2011-01-01

... REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL... issuance of licenses for the use of sealed sources containing byproduct material and radiation safety requirements for persons using these sealed sources in industrial radiography. The provisions and requirements...

10 CFR 34.1 - Purpose and scope.

Code of Federal Regulations, 2012 CFR

2012-01-01

... REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL... issuance of licenses for the use of sealed sources containing byproduct material and radiation safety requirements for persons using these sealed sources in industrial radiography. The provisions and requirements...

10 CFR 34.1 - Purpose and scope.

Code of Federal Regulations, 2014 CFR

2014-01-01

... REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL... issuance of licenses for the use of sealed sources containing byproduct material and radiation safety requirements for persons using these sealed sources in industrial radiography. The provisions and requirements...

First demonstration of 10 keV-width energy-discrimination K-edge radiography using a cadmium-telluride X-ray camera with a tungsten-target tube

NASA Astrophysics Data System (ADS)

Watanabe, Manabu; Sato, Eiichi; Abderyim, Purkhet; Abudurexiti, Abulajiang; Hagiwara, Osahiko; Matsukiyo, Hiroshi; Osawa, Akihiro; Enomoto, Toshiyuki; Nagao, Jiro; Sato, Shigehiro; Ogawa, Akira; Onagawa, Jun

2011-05-01

Energy-discrimination X-ray camera is useful to perform monochromatic radiography using polychromatic X-rays. This X-ray camera was developed to carry out K-edge radiography using cerium and gadolinium-based contrast media. In this camera, objects are irradiated by a cone beam from a tungsten-target X-ray generator, and penetrating X-ray photons are detected by a cadmium-telluride detector with amplifiers. Both optimal photon-energy level and energy width are selected using a multichannel analyzer, and the photon number is counted by a counter card. Radiography was performed by the detector scanning using an x- y stage driven by a two-stage controller, and radiograms were shown on a personal computer monitor. In radiography, tube voltage and current were 90 kV and 5.8 μA, respectively, and the X-ray intensity was 0.61 μGy/s at 1.0 m from the X-ray source. The K-edge energies of cerium and gadolinium are 40.3 and 50.3 keV, respectively, and 10 keV-width enhanced K-edge radiography was performed using X-ray photons with energies just beyond K-edge energies of cerium and gadolinium. Thus, cerium K-edge radiography was carried out using X-ray photons with an energy range from 40.3 to 50. 3 keV, and gadolinium K-edge radiography was accomplished utilizing photon energies ranging from 50.3 to 60.3 keV.

Thermal Neutron Radiography using a High-flux Compact Neutron Generator

NASA Astrophysics Data System (ADS)

Taylor, Michael; Sengbusch, Evan; Seyfert, Chris; Moll, Eli; Radel, Ross

A novel neutron imaging system has been designed and constructed by Phoenix Nuclear Labs to investigate specimens when conventional X-ray imaging will not suffice. A first-generation electronic neutron generator is actively being used by the United States Army and is coupled with activation films for neutron radiography to inspect munitions and other critical defence and aerospace components. A second-generation system has been designed to increase the total neutron output from an upgraded gaseous deuterium target to 5×1011 DD n/s, generating higher neutron flux at the imaging plane and dramatically reducing interrogation time, while maintaining high spatial resolution and low geometric unsharpness. A description of the neutron generator and imaging system, including the beamline, target and detector platform, is given in this paper. State of the art neutron moderators, collimators and imaging detector components are also discussed in the context of increasing specimen throughput and optimizing image quality. Neutron radiographs captured with the neutron radiography system will be further compared against simulated images using the MCNP nuclear simulation code.

Source characterization and modeling development for monoenergetic-proton radiography experiments on OMEGA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manuel, M. J.-E.; Zylstra, A. B.; Rinderknecht, H. G.

2012-06-15

A monoenergetic proton source has been characterized and a modeling tool developed for proton radiography experiments at the OMEGA [T. R. Boehly et al., Opt. Comm. 133, 495 (1997)] laser facility. Multiple diagnostics were fielded to measure global isotropy levels in proton fluence and images of the proton source itself provided information on local uniformity relevant to proton radiography experiments. Global fluence uniformity was assessed by multiple yield diagnostics and deviations were calculated to be {approx}16% and {approx}26% of the mean for DD and D{sup 3}He fusion protons, respectively. From individual fluence images, it was found that the angular frequenciesmore » of Greater-Than-Or-Equivalent-To 50 rad{sup -1} contributed less than a few percent to local nonuniformity levels. A model was constructed using the Geant4 [S. Agostinelli et al., Nuc. Inst. Meth. A 506, 250 (2003)] framework to simulate proton radiography experiments. The simulation implements realistic source parameters and various target geometries. The model was benchmarked with the radiographs of cold-matter targets to within experimental accuracy. To validate the use of this code, the cold-matter approximation for the scattering of fusion protons in plasma is discussed using a typical laser-foil experiment as an example case. It is shown that an analytic cold-matter approximation is accurate to within Less-Than-Or-Equivalent-To 10% of the analytic plasma model in the example scenario.« less

Improvement of the clinical use of computed radiography for mobile chest imaging: Image quality and patient dose

NASA Astrophysics Data System (ADS)

Rill, Lynn Neitzey

Chest radiography is technically difficult because of the wide variation of tissue attenuations in the chest and limitations of screen-film systems. Mobile chest radiography, performed bedside on hospital inpatients, presents additional difficulties due to geometrical and equipment limitations inherent to mobile x-ray procedures and the severity of illness in patients. Computed radiography (CR) offers a new approach for mobile chest radiography by utilizing a photostimulable phosphor. Photostimulable phosphors are more efficient in absorbing lower-energy x-rays than standard intensifying screens and overcome some image quality limitations of mobile chest imaging, particularly because of the inherent latitude. This study evaluated changes in imaging parameters for CR to take advantage of differences between CR and screen-film radiography. Two chest phantoms, made of acrylic and aluminum, simulated x-ray attenuation for average-sized and large- sized adult chests. The phantoms contained regions representing the lungs, heart and subdiaphragm. Acrylic and aluminum disks (1.9 cm diameter) were positioned in the chest regions to make signal-to-noise ratio (SNR) measurements for different combinations of imaging parameters. Disk thicknesses (contrast) were determined from disk visibility. Effective dose to the phantom was also measured for technique combinations. The results indicated that using an anti-scatter grid and lowering x- ray tube potential improved the SNR significantly; however, the dose to the phantom also increased. An evaluation was performed to examine the clinical applicability of the observed improvements in SNR. Parameter adjustments that improved phantom SNRs by more than 50% resulted in perceived image quality improvements in the lung region of clinical mobile chest radiographs. Parameters that produced smaller improvements in SNR had no apparent effect on clinical image quality. Based on this study, it is recommended that a 3:1 grid be used for

Detection of on-surface objects with an underground radiography detector system using cosmic-ray muons

NASA Astrophysics Data System (ADS)

Fujii, Hirofumi; Hara, Kazuhiko; Hayashi, Kohei; Kakuno, Hidekazu; Kodama, Hideyo; Nagamine, Kanetada; Sato, Kazuyuki; Sato, Kotaro; Kim, Shin-Hong; Suzuki, Atsuto; Takahashi, Kazuki; Takasaki, Fumihiko

2017-05-01

We have developed a compact muon radiography detector to investigate the status of the nuclear debris in the Fukushima Daiichi Reactors. Our previous observation showed that a large portion of the Unit-1 Reactor fuel had fallen to floor level. The detector must be located underground to further investigate the status of the fallen debris. To investigate the performance of muon radiography in such a situation, we observed 2 m cubic iron blocks located on the surface of the ground through different lengths of ground soil. The iron blocks were imaged and their corresponding iron density was derived successfully.

Proton Radiography at Los Alamos

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saunders, Alexander

2017-02-28

The proton radiography (pRad) facility at Los Alamos National Lab uses high energy protons to acquire multiple frame flash radiographic sequences at megahertz speeds: that is, it can make movies of the inside of explosions as they happen. The facility is primarily used to study the damage to and failure of metals subjected to the shock forces of high explosives as well as to study the detonation of the explosives themselves. Applications include improving our understanding of the underlying physical processes that drive the performance of the nuclear weapons in the United States stockpile and developing novel armor technologies inmore » collaboration with the Army Research Lab. The principle and techniques of pRad will be described, and examples of some recent results will be shown.« less

Flash Kα radiography of laser-driven solid sphere compression for fast ignition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sawada, H.; Lee, S.; Nagatomo, H.

2016-06-20

Time-resolved compression of a laser-driven solid deuterated plastic sphere with a cone was measured with flash Kα x-ray radiography. A spherically converging shockwave launched by nanosecond GEKKO XII beams was used for compression while a flash of 4.51 keV Ti Kα x-ray backlighter was produced by a high-intensity, picosecond laser LFEX (Laser for Fast ignition EXperiment) near peak compression for radiography. Areal densities of the compressed core were inferred from two-dimensional backlit x-ray images recorded with a narrow-band spherical crystal imager. The maximum areal density in the experiment was estimated to be 87 ± 26 mg/cm{sup 2}. The temporal evolution of the experimental andmore » simulated areal densities with a 2-D radiation-hydrodynamics code is in good agreement.« less

Inverse-collimated proton radiography for imaging thin materials

NASA Astrophysics Data System (ADS)

Freeman, Matthew S.; Allison, Jason; Andrews, Malcolm; Ferm, Eric; Goett, John J.; Kwiatkowski, Kris; Lopez, Julian; Mariam, Fesseha; Marr-Lyon, Mark; Martinez, Michael; Medina, Jason; Medina, Patrick; Merrill, Frank E.; Morris, Chris L.; Murray, Matthew M.; Nedrow, Paul; Neukirch, Levi P.; Prestridge, Katherine; Rigg, Paolo; Saunders, Alexander; Schurman, Tamsen; Tainter, Amy; Trouw, Frans; Tupa, Dale; Tybo, Josh; Vogan-McNeil, Wendy; Wilde, Carl

2017-01-01

Relativistic, magnetically focused proton radiography was invented at Los Alamos National Laboratory using the 800 MeV LANSCE beam and is inherently well-suited to imaging dense objects, at areal densities >20 g cm-2. However, if the unscattered portion of the transmitted beam is removed at the Fourier plane through inverse-collimation, this system becomes highly sensitive to very thin media, of areal densities <100 mg cm-2. Here, this inverse-collimation scheme is described in detail and demonstrated by imaging Xe gas with a shockwave generated by an aluminum plate compressing the gas at Mach 8.8. With a 5-mrad inverse collimator, an areal density change of just 49 mg cm-2 across the shock front is discernible with a contrast-to-noise ratio of 3. Geant4 modeling of idealized and realistic proton transports can guide the design of inverse-collimators optimized for specific experimental conditions and show that this technique performs better for thin targets with reduced incident proton beam emittance. This work increases the range of areal densities to which the system is sensitive to span from ˜25 mg cm-2 to 100 g cm-2, exceeding three orders of magnitude. This enables the simultaneous imaging of a dense system as well as thin jets and ejecta material that are otherwise difficult to characterize with high-energy proton radiography.

Inverse-collimated proton radiography for imaging thin materials.

PubMed

Freeman, Matthew S; Allison, Jason; Andrews, Malcolm; Ferm, Eric; Goett, John J; Kwiatkowski, Kris; Lopez, Julian; Mariam, Fesseha; Marr-Lyon, Mark; Martinez, Michael; Medina, Jason; Medina, Patrick; Merrill, Frank E; Morris, Chris L; Murray, Matthew M; Nedrow, Paul; Neukirch, Levi P; Prestridge, Katherine; Rigg, Paolo; Saunders, Alexander; Schurman, Tamsen; Tainter, Amy; Trouw, Frans; Tupa, Dale; Tybo, Josh; Vogan-McNeil, Wendy; Wilde, Carl

2017-01-01

Relativistic, magnetically focused proton radiography was invented at Los Alamos National Laboratory using the 800 MeV LANSCE beam and is inherently well-suited to imaging dense objects, at areal densities >20 g cm -2 . However, if the unscattered portion of the transmitted beam is removed at the Fourier plane through inverse-collimation, this system becomes highly sensitive to very thin media, of areal densities <100 mg cm -2 . Here, this inverse-collimation scheme is described in detail and demonstrated by imaging Xe gas with a shockwave generated by an aluminum plate compressing the gas at Mach 8.8. With a 5-mrad inverse collimator, an areal density change of just 49 mg cm -2 across the shock front is discernible with a contrast-to-noise ratio of 3. Geant4 modeling of idealized and realistic proton transports can guide the design of inverse-collimators optimized for specific experimental conditions and show that this technique performs better for thin targets with reduced incident proton beam emittance. This work increases the range of areal densities to which the system is sensitive to span from ∼25 mg cm -2 to 100 g cm -2 , exceeding three orders of magnitude. This enables the simultaneous imaging of a dense system as well as thin jets and ejecta material that are otherwise difficult to characterize with high-energy proton radiography.

Inverse-collimated proton radiography for imaging thin materials

DOE PAGES

Freeman, Matthew S.; Allison, Jason; Andrews, Malcolm; ...

2017-01-01

Relativistic, magnetically-focused proton radiography was invented at Los Alamos National Laboratory using the 800 MeV LANSCE beam, and is inherently well-suited to imaging dense objects, at areal densities >20 g cm -2. However, if the unscattered portion of the transmitted beam is removed at the Fourier plane through inverse-collimation, this system becomes highly sensitive to very thin media, of areal densities <100 mg cm -2. Here, this inversecollimation scheme is described in detail and demonstrated by imaging Xe gas with a shockwave generated by an aluminum plate compressing the gas at Mach 8.8. With a 5-mrad inverse collimator, an arealmore » density change of just 49 mg cm-2 across the shock front is discernible with a contrast-to-noise ratio of 3. Geant4 modeling of idealized and realistic proton transports can guide the design of inverse-collimators optimized for specific experimental conditions and show that this technique performs better for thin targets with reduced incident proton beam emittance. This work increases the range of areal densities to which the system is sensitive to span from ~25 mg cm -2 to 100 g cm -2, exceeding three orders of magnitude. This enables the simultaneous imaging of a dense system, as well as thin jets and ejecta material that are otherwise difficult to characterize with high-energy proton radiography.« less

[Comparative study between film mammography and xeromammography; including specimen radiography].

PubMed

Maeda, M; Hayakawa, K; Okuno, Y; Torizuka, T; Mitsumori, M; Soga, T; Misaki, T; Dokou, S; Ito, K

1990-10-01

We retrospectively evaluated preoperative film- and xeromammography of 23 cases with breast cancers, and compared with postoperative specimen radiography to assess tumor delineation and microcalcification detectability. In tumor detection and margin delineation, film mammography was superior to xeromammography, and in microcalcification, film mammography was equal to xeromammography. These results had a effect on the diagnosis of breast cancers.

10 CFR 34.11 - Application for a specific license.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Specific Licensing Provisions § 34.11 Application for a... industrial radiography on NRC Form 313, “Application for Material License,” in accordance with the provisions...

10 CFR Appendix A to Part 34 - Radiographer Certification

Code of Federal Regulations, 2012 CFR

2012-01-01

... NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Pt. 34, App. A Appendix A to Part 34—Radiographer Certification I... of industrial radiography; 2. Make its membership available to the general public nationwide that is...

10 CFR 34.11 - Application for a specific license.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Specific Licensing Provisions § 34.11 Application for a... industrial radiography on NRC Form 313, “Application for Material License,” in accordance with the provisions...

10 CFR Appendix A to Part 34 - Radiographer Certification

Code of Federal Regulations, 2011 CFR

2011-01-01

... NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Pt. 34, App. A Appendix A to Part 34—Radiographer Certification I... of industrial radiography; 2. Make its membership available to the general public nationwide that is...

10 CFR Appendix A to Part 34 - Radiographer Certification

Code of Federal Regulations, 2013 CFR

2013-01-01

... NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Pt. 34, App. A Appendix A to Part 34—Radiographer Certification I... of industrial radiography; 2. Make its membership available to the general public nationwide that is...

10 CFR 34.11 - Application for a specific license.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Specific Licensing Provisions § 34.11 Application for a... industrial radiography on NRC Form 313, “Application for Material License,” in accordance with the provisions...

10 CFR 34.11 - Application for a specific license.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Specific Licensing Provisions § 34.11 Application for a... industrial radiography on NRC Form 313, “Application for Material License,” in accordance with the provisions...

10 CFR 34.11 - Application for a specific license.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Specific Licensing Provisions § 34.11 Application for a... industrial radiography on NRC Form 313, “Application for Material License,” in accordance with the provisions...

10 CFR Appendix A to Part 34 - Radiographer Certification

Code of Federal Regulations, 2014 CFR

2014-01-01

... NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Pt. 34, App. A Appendix A to Part 34—Radiographer Certification I... of industrial radiography; 2. Make its membership available to the general public nationwide that is...

Improvement of density models of geological structures by fusion of gravity data and cosmic muon radiographies

NASA Astrophysics Data System (ADS)

Jourde, K.; Gibert, D.; Marteau, J.

2015-04-01

This paper examines how the resolution of small-scale geological density models is improved through the fusion of information provided by gravity measurements and density muon radiographies. Muon radiography aims at determining the density of geological bodies by measuring their screening effect on the natural flux of cosmic muons. Muon radiography essentially works like medical X-ray scan and integrates density information along elongated narrow conical volumes. Gravity measurements are linked to density by a 3-D integration encompassing the whole studied domain. We establish the mathematical expressions of these integration formulas - called acquisition kernels - and derive the resolving kernels that are spatial filters relating the true unknown density structure to the density distribution actually recovered from the available data. The resolving kernels approach allows to quantitatively describe the improvement of the resolution of the density models achieved by merging gravity data and muon radiographies. The method developed in this paper may be used to optimally design the geometry of the field measurements to perform in order to obtain a given spatial resolution pattern of the density model to construct. The resolving kernels derived in the joined muon/gravimetry case indicate that gravity data are almost useless to constrain the density structure in regions sampled by more than two muon tomography acquisitions. Interestingly the resolution in deeper regions not sampled by muon tomography is significantly improved by joining the two techniques. The method is illustrated with examples for La Soufrière of Guadeloupe volcano.

46 CFR 54.25-8 - Radiography (modifies UW-11(a), UCS-57, UNF-57, UHA-33, and UHT-57).

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 2 2014-10-01 2014-10-01 false Radiography (modifies UW-11(a), UCS-57, UNF-57, UHA-33, and UHT-57). 54.25-8 Section 54.25-8 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS Construction With Carbon, Alloy, and Heat Treated Steels § 54.25-8 Radiography (modifies UW-11(a), UCS-57, UNF...

46 CFR 54.25-8 - Radiography (modifies UW-11(a), UCS-57, UNF-57, UHA-33, and UHT-57).

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 2 2012-10-01 2012-10-01 false Radiography (modifies UW-11(a), UCS-57, UNF-57, UHA-33, and UHT-57). 54.25-8 Section 54.25-8 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS Construction With Carbon, Alloy, and Heat Treated Steels § 54.25-8 Radiography (modifies UW-11(a), UCS-57, UNF...

46 CFR 54.25-8 - Radiography (modifies UW-11(a), UCS-57, UNF-57, UHA-33, and UHT-57).

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 2 2013-10-01 2013-10-01 false Radiography (modifies UW-11(a), UCS-57, UNF-57, UHA-33, and UHT-57). 54.25-8 Section 54.25-8 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS Construction With Carbon, Alloy, and Heat Treated Steels § 54.25-8 Radiography (modifies UW-11(a), UCS-57, UNF...

46 CFR 54.25-8 - Radiography (modifies UW-11(a), UCS-57, UNF-57, UHA-33, and UHT-57).

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 2 2011-10-01 2011-10-01 false Radiography (modifies UW-11(a), UCS-57, UNF-57, UHA-33, and UHT-57). 54.25-8 Section 54.25-8 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS Construction With Carbon, Alloy, and Heat Treated Steels § 54.25-8 Radiography (modifies UW-11(a), UCS-57, UNF...

A review of dentists' use of digital radiography and caries diagnosis with digital systems.

PubMed

Wenzel, A

2006-09-01

To investigate the evidence for (1) dentists' use of digital radiography and (2) the outcome of caries diagnosis with digital systems. A literature search with the software search package PubMed was used to get internet-based access to Medline through the website www.ncbi.nlm.nih.gov/pubmed. The search was limited to the years 1999-2005 since most papers dealing with the diagnostic value of digital radiography systems published before 1999 will hold little interest for today's users due to changes in the systems. The search strategies resulted in 123 articles (Table 1, #4 and #5). Original research articles (not reviews) were selected by the following inclusion criteria: (1) questionnaire studies on the use of direct digital intraoral radiography systems (not digitized film), (2) studies which used human teeth and natural caries lesions, and further in laboratory studies, the sectioned tooth was the gold standard for validating the presence or depth of a lesion. The search resulted in 42 articles fulfilling the above criteria, which could be grouped into three types of studies: (a) questionnaire studies, (b) clinical (in vivo) studies, and (c) laboratory (in vitro) studies. Nine questionnaire studies, five clinical studies and 28 laboratory studies were found. These studies and their results are summarized in Tables 2-5. The number of studies was limited, and some of the digital systems were evaluated in only one or two studies. A conclusive judgment may therefore not be possible for the majority of the digital systems selected for this review. There is a continuous need for the evaluation of new digital intraoral radiography systems that appear on the market, first and foremost for their image quality and diagnostic accuracy, but certainly also for their performance in the clinic, a clear deficiency observed after the literature search for the present review.

X-ray vector radiography imaging for biomedical applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Potdevin, Guillaume; Malecki, Andreas; Biernath, Thomas

The non-invasive estimation of fracture risk in osteoporosis remains a challenge in the clinical routine and is mainly based on an assessment of bone density by dual X-ray absorption (DXA) although bone micro-architecture is known to play an important role for bone fragility. Here we report on 'X-ray vector Radiography' measurements able to provide a direct bone microstructure diagnostics on human bone samples, which we compare qualitatively and quantitatively with numerical analysis of high resolution radiographs.

Characterization of a gamma-ray source based on a laser-plasma accelerator with applications to radiography

NASA Astrophysics Data System (ADS)

Edwards, R. D.; Sinclair, M. A.; Goldsack, T. J.; Krushelnick, K.; Beg, F. N.; Clark, E. L.; Dangor, A. E.; Najmudin, Z.; Tatarakis, M.; Walton, B.; Zepf, M.; Ledingham, K. W. D.; Spencer, I.; Norreys, P. A.; Clarke, R. J.; Kodama, R.; Toyama, Y.; Tampo, M.

2002-03-01

The application of high intensity laser-produced gamma rays is discussed with regard to picosecond resolution deep-penetration radiography. The spectrum and angular distribution of these gamma rays is measured using an array of thermoluminescent detectors for both an underdense (gas) target and an overdense (solid) target. It is found that the use of an underdense target in a laser plasma accelerator configuration produces a much more intense and directional source. The peak dose is also increased significantly. Radiography is demonstrated in these experiments and the source size is also estimated.

Muscle parameters estimation based on biplanar radiography.

PubMed

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

2016-11-01

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

Does abdominal sonography provide additional information over abdominal plain radiography for diagnosis of necrotizing enterocolitis in neonates?

PubMed

Dilli, Dilek; Suna Oğuz, S; Erol, Reyhan; Ozkan-Ulu, Hülya; Dumanlı, Hüseyin; Dilmen, Uğur

2011-03-01

To explore whether addition of abdominal sonography (AUS) to plain radiography is helpful in the management of premature newborns with necrotizing enterocolitis (NEC). This study is a prospective analysis of 93 premature neonates with NEC who were followed-up in our neonatal intensive care unit between October 2007 and April 2009. Patients were classified into two groups; group I with suspected NEC (stage I) (n = 54) and group II with definite NEC (stage ≥II) (n = 39). Pneumatosis intestinalis (PI) (n = 29), free air (n = 9), and portal venous gas (PVG) (n = 1) were observed in group II on plain radiography. In the same group, echoic free fluid (EFF) (n = 9), PVG (n = 6), PI (n = 5), and focal fluid collection (n = 3) were the most prominent sonographic findings. In patients with intestinal perforation, whereas EFF and bowel wall thinning were observed on AUS, free air was not detected on plain radiography as a sign of intestinal perforation. Our results suggest AUS to be superior to plain radiography on early detection of intestinal perforation by demonstrating PVG and EFF collection. Therefore, it may be life-saving by directing the surgeon to perform surgical intervention in the case of clinical deterioration in the course of NEC.

Comparison of Metallic Foreign-Body Removal between Dynamic Ultrasound and Static Radiography in a Pigs' Feet Model

PubMed Central

Manson, William C; Ryan, James G; Ladner, Heidi; Gupta, Sanjey

2011-01-01

Introduction We compared the immediate cosmetic outcome of metallic foreign-body removal by emergency medicine (EM) residents with ultrasound guidance and conventional radiography. Methods This single-blinded, randomized, crossover study evaluated the ability of EM residents to remove metallic pins embedded in pigs' feet. Before the experiment, we embedded 1.5-cm metallic pins into numbered pigs' feet. We randomly assigned 14 EM residents to use either ultrasound or radiography to help remove the foreign body. Residents had minimal ultrasound experience. After a brief lecture, we provided residents with a scalpel, laceration kit, a bedside portable ultrasound machine, nipple markers, paper clips, a dedicated radiograph technician, and radiograph machine 20 feet away. After removal, 3 board-certified emergency physicians, who were blinded to the study group, evaluated the soft-tissue model by using a standardized form. They recorded incision length and cosmetic appearance on the Visual Analog Scale. Results In total, 28 foreign bodies were removed. No significant difference in the time of removal (P = 0.12), cosmetic appearance (P = 0.96), or incision length (P = 0.76) was found. Conclusion This study showed no difference between bedside ultrasound and radiography in assisting EM residents with metallic foreign-body removal from soft tissue. No significant difference was found in removal time or cosmetic outcome when comparing ultrasound with radiography. PMID:22224139

Combining Radiography and Passive Measurements for Radiological Threat Localization in Cargo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, Erin A.; White, Timothy A.; Jarman, Kenneth D.

Detecting shielded special nuclear material (SNM) in a cargo container is a difficult problem, since shielding reduces the amount of radiation escaping the container. Radiography provides information that is complementary to that provided by passive gamma-ray detection systems: while not directly sensitive to radiological materials, radiography can reveal highly shielded regions that may mask a passive radiological signal. Combining these measurements has the potential to improve SNM detection, either through improved sensitivity or by providing a solution to the inverse problem to estimate source properties (strength and location). We present a data-fusion method that uses a radiograph to provide anmore » estimate of the radiation-transport environment for gamma rays from potential sources. This approach makes quantitative use of radiographic images without relying on image interpretation, and results in a probabilistic description of likely source locations and strengths. We present results for this method for a modeled test case of a cargo container passing through a plastic-scintillator-based radiation portal monitor and a transmission-radiography system. We find that a radiograph-based inversion scheme allows for localization of a low-noise source placed randomly within the test container to within 40 cm, compared to 70 cm for triangulation alone, while strength estimation accuracy is improved by a factor of six. Improvements are seen in regions of both high and low shielding, but are most pronounced in highly shielded regions. The approach proposed here combines transmission and emission data in a manner that has not been explored in the cargo-screening literature, advancing the ability to accurately describe a hidden source based on currently-available instrumentation.« less

Combining Radiography and Passive Measurements for Radiological Threat Localization in Cargo

NASA Astrophysics Data System (ADS)

Miller, Erin A.; White, Timothy A.; Jarman, Kenneth D.; Kouzes, Richard T.; Kulisek, Jonathan A.; Robinson, Sean M.; Wittman, Richard A.

2015-10-01

Detecting shielded special nuclear material (SNM) in a cargo container is a difficult problem, since shielding reduces the amount of radiation escaping the container. Radiography provides information that is complementary to that provided by passive gamma-ray detection systems: while not directly sensitive to radiological materials, radiography can reveal highly shielded regions that may mask a passive radiological signal. Combining these measurements has the potential to improve SNM detection, either through improved sensitivity or by providing a solution to the inverse problem to estimate source properties (strength and location). We present a data-fusion method that uses a radiograph to provide an estimate of the radiation-transport environment for gamma rays from potential sources. This approach makes quantitative use of radiographic images without relying on image interpretation, and results in a probabilistic description of likely source locations and strengths. We present results for this method for a modeled test case of a cargo container passing through a plastic-scintillator-based radiation portal monitor and a transmission-radiography system. We find that a radiograph-based inversion scheme allows for localization of a low-noise source placed randomly within the test container to within 40 cm, compared to 70 cm for triangulation alone, while strength estimation accuracy is improved by a factor of six. Improvements are seen in regions of both high and low shielding, but are most pronounced in highly shielded regions. The approach proposed here combines transmission and emission data in a manner that has not been explored in the cargo-screening literature, advancing the ability to accurately describe a hidden source based on currently-available instrumentation.

Digital radiography using amorphous selenium: photoconductively activated switch (PAS) readout system.

PubMed

Reznik, Nikita; Komljenovic, Philip T; Germann, Stephen; Rowlands, John A

2008-03-01

A new amorphous selenium (a-Se) digital radiography detector is introduced. The proposed detector generates a charge image in the a-Se layer in a conventional manner, which is stored on electrode pixels at the surface of the a-Se layer. A novel method, called photoconductively activated switch (PAS), is used to read out the latent x-ray charge image. The PAS readout method uses lateral photoconduction at the a-Se surface which is a revolutionary modification of the bulk photoinduced discharge (PID) methods. The PAS method addresses and eliminates the fundamental weaknesses of the PID methods--long readout times and high readout noise--while maintaining the structural simplicity and high resolution for which PID optical readout systems are noted. The photoconduction properties of the a-Se surface were investigated and the geometrical design for the electrode pixels for a PAS radiography system was determined. This design was implemented in a single pixel PAS evaluation system. The results show that the PAS x-ray induced output charge signal was reproducible and depended linearly on the x-ray exposure in the diagnostic exposure range. Furthermore, the readout was reasonably rapid (10 ms for pixel discharge). The proposed detector allows readout of half a pixel row at a time (odd pixels followed by even pixels), thus permitting the readout of a complete image in 30 s for a 40 cm x 40 cm detector with the potential of reducing that time by using greater readout light intensity. This demonstrates that a-Se based x-ray detectors using photoconductively activated switches could form a basis for a practical integrated digital radiography system.

A Feasibility Study on Reactor Based Fission Neutron Radiography of 200-l Waste Packages

NASA Astrophysics Data System (ADS)

Bücherl, T.; Kalthoff, O.; von Gostomski, Ch. Lierse

This feasibility study investigates the applicability of fission neutrons for the non-destructive characterization of radioactive waste packages by means of neutron radiography. Based on a number of mock-up drums of different non-radioactive matrices, but being typical for radioactive waste generated in Europe, radiography measurements at the NECTAR and the ITS facility using fission neutrons and 60Co-gamma-rays, respectively, are performed. The resulting radiographs are compared and qualitatively assessed. In addition, a first approach for the stitching of the fission neutron radiographs to visualize the complete area of 200-l waste drums is performed. While the feasibility of fission neutrons is demonstrated successfully, fields for further improvements are identified.

Feasibility of using neutron radiography to inspect the Space Shuttle solid rocket booster aft skirt, forward skirt and frustum. Part 1: Summary report

NASA Technical Reports Server (NTRS)

Barton, J. P.; Bader, J. W.; Brenizer, J. S.; Hosticka, B.

1992-01-01

The space shuttle's solid rocket boosters (SRB) include components made primarily of aluminum that are parachuted back for retrieval from the ocean and refurbished for repeated usage. Nondestructive inspection methods used on these aging parts to reduce the risk of unforeseen problems include x-ray, ultrasonics, and eddy current. Neutron radiography tests on segments of an SRB component show that entrapped moisture and naturally occurring aluminum corrosion can be revealed by neutron radiography even if present in only small amounts. Voids in sealant can also be evaluated. Three alternatives are suggested to follow-up this study: (1) take an SRB component to an existing neutron radiography system; (2) take an existing mobile neutron radiography system to the NASA site; or (3) plan a dedicated system custom designed for NASA applications.

Comparison of Diagnostic Performance of Semi-Quantitative Knee Ultrasound and Knee Radiography with MRI: Oulu Knee Osteoarthritis Study.

PubMed

Podlipská, Jana; Guermazi, Ali; Lehenkari, Petri; Niinimäki, Jaakko; Roemer, Frank W; Arokoski, Jari P; Kaukinen, Päivi; Liukkonen, Esa; Lammentausta, Eveliina; Nieminen, Miika T; Tervonen, Osmo; Koski, Juhani M; Saarakkala, Simo

2016-03-01

Osteoarthritis (OA) is a common degenerative musculoskeletal disease highly prevalent in aging societies worldwide. Traditionally, knee OA is diagnosed using conventional radiography. However, structural changes of articular cartilage or menisci cannot be directly evaluated using this method. On the other hand, ultrasound is a promising tool able to provide direct information on soft tissue degeneration. The aim of our study was to systematically determine the site-specific diagnostic performance of semi-quantitative ultrasound grading of knee femoral articular cartilage, osteophytes and meniscal extrusion, and of radiographic assessment of joint space narrowing and osteophytes, using MRI as a reference standard. Eighty asymptomatic and 79 symptomatic subjects with mean age of 57.7 years were included in the study. Ultrasound performed best in the assessment of femoral medial and lateral osteophytes, and medial meniscal extrusion. In comparison to radiography, ultrasound performed better or at least equally well in identification of tibio-femoral osteophytes, medial meniscal extrusion and medial femoral cartilage morphological degeneration. Ultrasound provides relevant additional diagnostic information on tissue-specific morphological changes not depicted by conventional radiography. Consequently, the use of ultrasound as a complementary imaging tool along with radiography may enable more accurate and cost-effective diagnostics of knee osteoarthritis at the primary healthcare level.

Methods: a comparative analysis of radiography, microcomputed tomography, and histology for bone tissue engineering.

PubMed

Hedberg, Elizabeth L; Kroese-Deutman, Henriette C; Shih, Charles K; Lemoine, Jeremy J; Liebschner, Michael A K; Miller, Michael J; Yasko, Alan W; Crowther, Roger S; Carney, Darrell H; Mikos, Antonios G; Jansen, John A

2005-01-01

This study focused on the assessment of radiography, microcomputed tomography, and histology for the evaluation of bone formation in a 15.0-mm defect in the rabbit radius after the implantation of a tissue-engineered construct. Radiography was found to be useful as a noninvasive method for obtaining images of calcified tissue throughout the time course of the experiment. With this method, however, image quality was low, making it difficult to obtain precise information about the location and quantity of the bone formed. Microcomputed tomography was used to create three-dimensional reconstructions of the bone (25-microm resolution). These reconstructions allowed for greater spatial resolution than the radiography, but did not allow for imaging of the implanted scaffold material or the surrounding, nonmineralized tissue. To visualize all materials within the defect area at the cellular level, histology was used. Histological analysis, however, is a destructive technique that did not allow for any further analysis of the samples. Each technique examined here has its own advantages and limitations, but each yields unique information regarding bone regeneration. It is only through the use of all three techniques that complete characterization of the bone growth and tissue/construct responses after implantation in vivo.

Mobile radiography CQI: an inter-national study.

PubMed

Kamat, M R; Wein, B; Cohan, R

1999-01-01

Mobile or bedside radiography has been and is a staple diagnostic and follow-up tool used readily by the many medical disciplines, such as cardiology, surgery, orthopedics, pediatrics, neonatology, etc. Ironically, in the past a student or the least qualified technologist was sent to perform the bedside exam. Moreover, it was almost expected that poor but acceptable film quality would result or that repeat films were almost always to be taken. Inefficiency with respect to quality of exam, the time the exam takes, or film repeats can be costly. The price of inefficiency is the cost involved in doing things incorrectly or not in the most efficient manner, i.e., incurring inefficiencies instead of operating in an ideal manner. The purpose of this study was to compare the total cost of inefficiently organized, scheduled and performed mobile radiography at three large teaching hospitals in various locations and of diverse patient loads, as a means of determining how best to increase utilization and performance. The study was performed at the 489-bed New England Deaconess Hospital (NEDH), the 644-bed Sentara Norfolk General Hospital (SNGH), and the 1500-bed Rheinische Westfalische Technische Hochschule (RWTH) in Aachen, Germany. Similar standardized study methods were utilized at all three institutions where extended observation of mobile utilization, areas of inefficiency, time wasted per episode and number of episodes per time period were determined. Data were loggedin at three standardized time periods, summated, and then multiplied by technologist hourly pay rate. This sum was extrapolated over 52 weeks to give the total annual cost of inefficiently organized mobile radiography. For NEDH the cost of total inefficiency was $75,453, for SNGH $49,586, while for RWTH it was $9,519. Eighteen areas of inefficiency were identified and grouped, such as lack of spatial cohesiveness and lack of communication leading to film duplication, etc. While inefficiencies in the

Intercomparison of gamma scattering, gammatography, and radiography techniques for mild steel nonuniform corrosion detection

NASA Astrophysics Data System (ADS)

Priyada, P.; Margret, M.; Ramar, R.; Shivaramu, Menaka, M.; Thilagam, L.; Venkataraman, B.; Raj, Baldev

2011-03-01

This paper focuses on the mild steel (MS) corrosion detection and intercomparison of results obtained by gamma scattering, gammatography, and radiography techniques. The gamma scattering non-destructive evaluation (NDE) method utilizes scattered gamma radiation for the detection of corrosion, and the scattering experimental setup is an indigenously designed automated personal computer (PC) controlled scanning system consisting of computerized numerical control (CNC) controlled six-axis source detector system and four-axis job positioning system. The system has been successfully used to quantify the magnitude of corrosion and the thickness profile of a MS plate with nonuniform corrosion, and the results are correlated with those obtained from the conventional gammatography and radiography imaging measurements. A simple and straightforward reconstruction algorithm to reconstruct the densities of the objects under investigation and an unambiguous interpretation of the signal as a function of material density at any point of the thick object being inspected is described. In this simple and straightforward method the density of the target need not be known and only the knowledge of the target material's mass attenuation coefficients (composition) for the incident and scattered energies is enough to reconstruct the density of the each voxel of the specimen being studied. The Monte Carlo (MC) numerical simulation of the phenomena is done using the Monte Carlo N-Particle Transport Code (MCNP) and the quantitative estimates of the values of signal-to-noise ratio for different percentages of MS corrosion derived from these simulations are presented and the spectra are compared with the experimental data. The gammatography experiments are carried out using the same PC controlled scanning system in a narrow beam, good geometry setup, and the thickness loss is estimated from the measured transmitted intensity. Radiography of the MS plates is carried out using 160 kV x

ADVANCEMENTS IN NEUTRON RADIOGRAPHY WITHIN THE DEPARTMENT OF THE ARMY

DTIC Science & Technology

2016-11-01

Defense (DoD) production facility for direct use in quality control of munitions and weapons system by means of neutron radiographic inspection...UNCLASSIFIED UNCLASSIFIED AD-E403 813 Technical Report AREIS-TR-16004 ADVANCEMENTS IN NEUTRON RADIOGRAPHY WITHIN THE...REPORT DATE (DD-MM-YYYY) November 2016 2. REPORT TYPE Final 3. DATES COVERED (From – To) 4. TITLE AND SUBTITLE ADVANCEMENTS IN NEUTRON

Focusing mirrors for enhanced neutron radiography with thermal neutrons and application for irradiated nuclear fuel

NASA Astrophysics Data System (ADS)

Rai, Durgesh K.; Abir, Muhammad; Wu, Huarui; Khaykovich, Boris; Moncton, David E.

2018-01-01

Neutron radiography is a powerful method of probing the structure of materials based on attenuation of neutrons. This method is most suitable for materials containing heavy metals, which are not transparent to X-rays, for example irradiated nuclear fuel and other nuclear materials. Neutron radiography is one of the first non-distractive post-irradiated examination methods, which is applied to gain an overview of the integrity of irradiated nuclear fuel and other nuclear materials. However, very powerful gamma radiation emitted by the samples is damaging to the electronics of digital imaging detectors and has so far precluded the use of modern detectors. Here we describe a design of a neutron microscope based on focusing mirrors suitable for thermal neutrons. As in optical microscopes, the sample is separated from the detector, decreasing the effect of gamma radiation. In addition, the application of mirrors would result in a thirty-fold gain in flux and a resolution of better than 40 μm for a field-of-view of about 2.5 cm. Such a thermal neutron microscope can be useful for other applications of neutron radiography, where thermal neutrons are advantageous.

Determination of the resolution of a digital system for panoramic radiography based on CCD technology.

PubMed

Mastoris, Mihalis; Li, Gang; Welander, Ulf; McDavid, W D

2004-03-01

To determine Line Spread Functions (LSFs) and Modulation Transfer Functions (MTFs) for a digital system for panoramic radiography: the Dimax I (Planmeca Oy, Helsinki, Finland) based on Charge-Coupled Device (CCD) technology. A test object was specially designed having a gold foil positioned vertically. Images of the gold foil created edge functions that were used to determine LSFs and MTFs. The design of the test object made it possible to move the gold foil forward and backward relative to the central plane of the image layer by means of a micrometer screw. The experiment was carried out for different object depths in 5 different regions: the anterior, the canine, the premolar, the molar, and the TMJ regions. LSFs and MTFs were calculated using specially designed software. The results are presented graphically. LSFs and MTFs for the central plane were essentially the same for all regions. The MTFs for different object depths in the 5 investigated regions exhibited typical characteristics of MTFs for panoramic radiography with the exception for the functions for the molar region. The present findings indicate that the resolution of the Dimax I CCD system is comparable to that of film-based panoramic radiography.

Evaluation of Publicly Available Documents to Trace Chiropractic Technique Systems That Advocate Radiography for Subluxation Analysis: A Proposed Genealogy

PubMed Central

Young, Kenneth J.

2014-01-01

Objective The purpose of this study was to evaluate publicly available information of chiropractic technique systems that advocate radiography for subluxation detection to identify links between chiropractic technique systems and to describe claims made of the health effects of the osseous misalignment component of the chiropractic subluxation and radiographic paradigms. Methods The Internet and publicly available documents were searched for information representing chiropractic technique systems that advocate radiography for subluxation detection. Key phrases including chiropractic, x-ray, radiography, and technique were identified from a Google search between April 2013 and March 2014. Phrases in Web sites and public documents were examined for any information about origins and potential links between these techniques, including the type of connection to BJ Palmer, who was the first chiropractor to advocate radiography for subluxation detection. Quotes were gathered to identify claims of health effects from osseous misalignment (subluxation) and paradigms of radiography. Techniques were grouped by region of the spine and how they could be traced back to B.J Palmer. A genealogy model and summary table of information on each technique were created. Patterns in year of origination and radiographic paradigms were noted, and percentages were calculated on elements of the techniques’ characteristics in comparison to the entire group. Results Twenty-three techniques were identified on the Internet: 6 full spine, 17 upper cervical, and 2 techniques generating other lineage. Most of the upper cervical techniques (14/16) traced their origins to a time when the Palmer School was teaching upper cervical technique, and all the full spine techniques (6/6) originated before or after this phase. All the technique systems’ documents attributed broad health effects to their methods. Many (21/23) of the techniques used spinal realignment on radiographs as one of their outcome

Evaluation of publicly available documents to trace chiropractic technique systems that advocate radiography for subluxation analysis: a proposed genealogy.

PubMed

Young, Kenneth J

2014-12-01

The purpose of this study was to evaluate publicly available information of chiropractic technique systems that advocate radiography for subluxation detection to identify links between chiropractic technique systems and to describe claims made of the health effects of the osseous misalignment component of the chiropractic subluxation and radiographic paradigms. The Internet and publicly available documents were searched for information representing chiropractic technique systems that advocate radiography for subluxation detection. Key phrases including chiropractic, x-ray, radiography, and technique were identified from a Google search between April 2013 and March 2014. Phrases in Web sites and public documents were examined for any information about origins and potential links between these techniques, including the type of connection to BJ Palmer, who was the first chiropractor to advocate radiography for subluxation detection. Quotes were gathered to identify claims of health effects from osseous misalignment (subluxation) and paradigms of radiography. Techniques were grouped by region of the spine and how they could be traced back to B.J Palmer. A genealogy model and summary table of information on each technique were created. Patterns in year of origination and radiographic paradigms were noted, and percentages were calculated on elements of the techniques' characteristics in comparison to the entire group. Twenty-three techniques were identified on the Internet: 6 full spine, 17 upper cervical, and 2 techniques generating other lineage. Most of the upper cervical techniques (14/16) traced their origins to a time when the Palmer School was teaching upper cervical technique, and all the full spine techniques (6/6) originated before or after this phase. All the technique systems' documents attributed broad health effects to their methods. Many (21/23) of the techniques used spinal realignment on radiographs as one of their outcome measures. Chiropractic

Evaluation of ultrasonics and optimized radiography for 2219-T87 aluminum weldments

NASA Technical Reports Server (NTRS)

Clotfelter, W. N.; Hoop, J. M.; Duren, P. C.

1975-01-01

Ultrasonic studies are described which are specifically directed toward the quantitative measurement of randomly located defects previously found in aluminum welds with radiography or with dye penetrants. Experimental radiographic studies were also made to optimize techniques for welds of the thickness range to be used in fabricating the External Tank of the Space Shuttle. Conventional and innovative ultrasonic techniques were applied to the flaw size measurement problem. Advantages and disadvantages of each method are discussed. Flaw size data obtained ultrasonically were compared to radiographic data and to real flaw sizes determined by destructive measurements. Considerable success was achieved with pulse echo techniques and with 'pitch and catch' techniques. The radiographic work described demonstrates that careful selection of film exposure parameters for a particular application must be made to obtain optimized flaw detectability. Thus, film exposure techniques can be improved even though radiography is an old weld inspection method.

Comparison of Radiography and Ultrasonography for Diagnosis of Diaphragmatic Hernia in Bovines

PubMed Central

Athar, Hakim; Mohindroo, Jitender; Singh, Kiranjeet; Kumar, Ashwani; Raghunath, Mulinti

2010-01-01

The present study was conducted on 101 animals suffering from thoracoabdominal disorders; out of which twenty seven animals (twenty six buffaloes and one cow) were diagnosed with diaphragmatic hernia based on clinical signs, radiography, ultrasonography, and left flank laparorumenotomy. Radiography alone confirmed diaphragmatic hernia in 18 cases (66.67%) with a sac-like structure cranial to the diaphragm. In 15 animals the sac contained metallic densities while in three cases a sac-like structure with no metallic densities was present. Ultrasonography was helpful in confirming diaphragmatic hernia in 23 cases (85.18%) and ultrasonographically reticular motility was evident at the level of 4th/5th intercostal space in all the animals. B+M mode ultrasonography was used for the first time for diagnosis of diaphragmatic hernia in bovines and the results suggested that ultrasonography was a reliable diagnostic modality for diaphragmatic hernia in bovines. PMID:20445795

10 CFR 34.53 - Posting.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Posting. 34.53 Section 34.53 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Radiation Safety Requirements § 34.53 Posting. All areas in which industrial radiography is being...

10 CFR 34.53 - Posting.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 1 2013-01-01 2013-01-01 false Posting. 34.53 Section 34.53 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Radiation Safety Requirements § 34.53 Posting. All areas in which industrial radiography is being...

10 CFR 34.53 - Posting.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 1 2014-01-01 2014-01-01 false Posting. 34.53 Section 34.53 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Radiation Safety Requirements § 34.53 Posting. All areas in which industrial radiography is being...

10 CFR 34.53 - Posting.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 1 2011-01-01 2011-01-01 false Posting. 34.53 Section 34.53 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Radiation Safety Requirements § 34.53 Posting. All areas in which industrial radiography is being...

10 CFR 34.53 - Posting.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 1 2012-01-01 2012-01-01 false Posting. 34.53 Section 34.53 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Radiation Safety Requirements § 34.53 Posting. All areas in which industrial radiography is being...

Observer training for computer-aided detection of pulmonary nodules in chest radiography.

PubMed

De Boo, Diederick W; van Hoorn, François; van Schuppen, Joost; Schijf, Laura; Scheerder, Maeke J; Freling, Nicole J; Mets, Onno; Weber, Michael; Schaefer-Prokop, Cornelia M

2012-08-01

To assess whether short-term feedback helps readers to increase their performance using computer-aided detection (CAD) for nodule detection in chest radiography. The 140 CXRs (56 with a solitary CT-proven nodules and 84 negative controls) were divided into four subsets of 35; each were read in a different order by six readers. Lesion presence, location and diagnostic confidence were scored without and with CAD (IQQA-Chest, EDDA Technology) as second reader. Readers received individual feedback after each subset. Sensitivity, specificity and area under the receiver-operating characteristics curve (AUC) were calculated for readings with and without CAD with respect to change over time and impact of CAD. CAD stand-alone sensitivity was 59 % with 1.9 false-positives per image. Mean AUC slightly increased over time with and without CAD (0.78 vs. 0.84 with and 0.76 vs. 0.82 without CAD) but differences did not reach significance. The sensitivity increased (65 % vs. 70 % and 66 % vs. 70 %) and specificity decreased over time (79 % vs. 74 % and 80 % vs. 77 %) but no significant impact of CAD was found. Short-term feedback does not increase the ability of readers to differentiate true- from false-positive candidate lesions and to use CAD more effectively. • Computer-aided detection (CAD) is increasingly used as an adjunct for many radiological techniques. • Short-term feedback does not improve reader performance with CAD in chest radiography. • Differentiation between true- and false-positive CAD for low conspicious possible lesions proves difficult. • CAD can potentially increase reader performance for nodule detection in chest radiography.

Establishment of local diagnostic reference levels for quality control in intraoral radiography.

PubMed

Izawa, Maki; Harata, Yasuo; Shiba, Noriyoshi; Koizumi, Nobuhide; Ozawa, Tomonori; Takahashi, Nobutoshi; Okumura, Yasuhiko

2017-01-01

To investigate the dosage and imaging conditions for patients undergoing intraoral radiography at Meikai University Hospital and establish assurance and quality control data. Tube voltage, exposure time, and air kinetic energy released per unit mass (air kerma) of three intraoral radiography units were measured. To calculate the patient entrance dose (PED) for each radiograph using Insight film, we extracted data for 1063 patients from their exposure records. The PED was compared with the diagnostic reference level (DRL) from the European Commission and the UK. The tube voltage of the three units was maintained at 60 ± 2 kV. Differences in exposure time were less than 1.7 % for all units. The air kerma rates were well maintained within a 4.2 % error. Based on the patient data, there were no significant differences in the mean exposure times for males and females for all anatomical sites. The mean PED ranged from 1.09 ± 0.31 mGy for the mandibular incisors to 2.42 ± 0.33 mGy for the maxillary molars. The mean PED at the mandibular molars using InSight film was 1.59 ± 0.20 mGy, being less than the recommended value based on the DRL for intraoral radiography in the UK. We concluded that radiographic conditions at the hospital have been properly maintained. This basic quality control data may assist other dental radiation facilities to reduce patient dosage.

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

PubMed

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

2015-01-01

Gender determination is frequently requested by reptile breeders, especially for species with poor or absent sexual dimorphism. The aims of the current study were to describe techniques and diagnostic sensitivities of ultrasound, radiography, and computed tomography for gender determination (identification of hemipenes) in four species of lizards. Nineteen lizards of known sex, belonging to four different species (Pogona vitticeps, Uromastyx aegyptia, Tiliqua scincoides, Gerrhosaurus major) were prospectively enrolled. With informed owner consent, ultrasound, noncontrast CT, contrast radiography, and contrast CT (with contrast medium administered into the cloaca) were performed in conscious animals. Imaging studies were reviewed by three different operators, each unaware of the gender of the animals and of the results of the other techniques. The lizard was classified as a male when hemipenes were identified. Nineteen lizards were included in the study, 10 females and nine males. The hemipenes were seen on ultrasound in only two male lizards, and appeared as oval hypoechoic structures. Radiographically, hemipenes filled with contrast medium appeared as spindle-shaped opacities. Noncontrast CT identified hemipenes in only two lizards, and these appeared as spindle-shaped kinked structures with hyperattenuating content consistent with smegma. Hemipenes were correctly identified in all nine males using contrast CT (accuracy of 100%). Accuracy of contrast radiography was excellent (94.7%). Accuracy of ultrasound and of noncontrast CT was poor (64.3% and 63.1%, respectively). Findings from the current study supported the use of contrast CT or contrast radiography for gender determination in lizards. © 2014 American College of Veterinary Radiology.

Improvement of density models of geological structures by fusion of gravity data and cosmic muon radiographies

NASA Astrophysics Data System (ADS)

Jourde, K.; Gibert, D.; Marteau, J.

2015-08-01

This paper examines how the resolution of small-scale geological density models is improved through the fusion of information provided by gravity measurements and density muon radiographies. Muon radiography aims at determining the density of geological bodies by measuring their screening effect on the natural flux of cosmic muons. Muon radiography essentially works like a medical X-ray scan and integrates density information along elongated narrow conical volumes. Gravity measurements are linked to density by a 3-D integration encompassing the whole studied domain. We establish the mathematical expressions of these integration formulas - called acquisition kernels - and derive the resolving kernels that are spatial filters relating the true unknown density structure to the density distribution actually recovered from the available data. The resolving kernel approach allows one to quantitatively describe the improvement of the resolution of the density models achieved by merging gravity data and muon radiographies. The method developed in this paper may be used to optimally design the geometry of the field measurements to be performed in order to obtain a given spatial resolution pattern of the density model to be constructed. The resolving kernels derived in the joined muon-gravimetry case indicate that gravity data are almost useless for constraining the density structure in regions sampled by more than two muon tomography acquisitions. Interestingly, the resolution in deeper regions not sampled by muon tomography is significantly improved by joining the two techniques. The method is illustrated with examples for the La Soufrière volcano of Guadeloupe.

Low material budget floating strip Micromegas for ion transmission radiography

NASA Astrophysics Data System (ADS)

Bortfeldt, J.; Biebel, O.; Flierl, B.; Hertenberger, R.; Klitzner, F.; Lösel, Ph.; Magallanes, L.; Müller, R.; Parodi, K.; Schlüter, T.; Voss, B.; Zibell, A.

2017-02-01

Floating strip Micromegas are high-accuracy and discharge insensitive gaseous detectors, able to track single particles at fluxes of 7 MHz/cm2 with 100 μm resolution. We developed low-material-budget detectors with one-dimensional strip readout, suitable for tracking at highest particle rates as encountered in medical ion transmission radiography or inner tracker applications. Recently we additionally developed Kapton-based floating strip Micromegas with two-dimensional strip readout, featuring an overall thickness of 0.011 X0. These detectors were tested in high-rate proton and carbon-ion beams at the tandem accelerator in Garching and the Heidelberg Ion-Beam Therapy Center, operated with an optimized Ne:CF4 gas mixture. By coupling the Micromegas detectors to a new scintillator based range detector, ion transmission radiographies of PMMA and tissue-equivalent phantoms were acquired. The range detector with 18 layers is read out via wavelength shifting fibers, coupled to a multi-anode photomultiplier. We present the performance of the Micromegas detectors with respect to timing and single plane track reconstruction using the μTPC method. We discuss the range resolution of the scintillator range telescope and present the image reconstruction capabilities of the combined system.

Ultrasonographic localization of the thyroid gland for its optimal shielding prior to lateral cephalometric radiography: a pilot study

PubMed Central

Hurmerinta, Kirsti; Rice, David; Suomalainen, Anni

2016-01-01

Objectives: Lateral cephalometric radiography is a common radiographic examination technique in children. The exclusion of the thyroid gland from the primary X-ray beam is important especially with children. However, patient treatment might require displaying the four most cranial cervical vertebrae (C1–C4) for the assessment of cervical vertebral maturation. Our aim was to present a safe way to display C1–C4 and exclude the thyroid gland from the X-ray beam during lateral cephalometric radiography. Methods: The thyroid glands of 25, 7- to 12-year-old patients were localized by ultrasound examination and shielded prior to lateral cephalometric radiography. A roentgen-positive mark was taped on the patient's skin at the level of most cranial level of the thyroid gland in the midsagittal plane. After exposure, each lateral cephalometric radiograph (LCR) was analyzed for the visibility of the cervical vertebrae. The distance between the ear post and the highest edge of the thyroid shield (TS) at the lateral part of the neck was measured and compared with the distance between the centre of the radiological external auditory meatus, and a roentgen-positive mark was made on the LCR. Results: 68% of the LCRs displayed C1–C4, and the rest of them displayed C1–C3. In all of the patients, the highest edge of the TS in the lateral parts of the neck was located in a higher position than the actual most cranial level of the thyroid gland. Conclusions: Despite localizing the thyroid gland prior to lateral cephalometric radiography, simultaneous visualization of C1–C4 and exclusion of the thyroid gland from the primary X-ray beam during lateral cephalometric radiography might not be completely possible in children because of the design and poor fitness of the TS. PMID:26764584

[Comparison of projection radiography and computed tomography for the detection of pulmonary nodules in the dog and cat].

PubMed

Niesterok, C; Köhler, C; Ludewig, E; Alef, M; Oechtering, G; Kiefer, I

2013-01-01

The aim of our study was to evaluate the value of projection radiography as a standard screening method for the detection of lung nodules compared to computed tomography (CT). Furthermore, we attempted to describe the reasons that might lead to a failed detection of pulmonary nodules in radiography. From dogs and cats which were diagnosed in CT (multislice CT) with nodular changes in the lung pattern we selected radiographs (projection radiography with soft copy reading) in at least two projection planes produced in the same timeframe as the CT images. Exclusion criteria were nodules > 3 cm and homogenously calcified nodules (osteomata). A total of 70 animals (50 dogs and 20 cats) met the inclusion criteria. In 43 animals (61%), nodular changes had already been detected using radiography and were then confirmed by the results of the computed tomography. In detail, 32 of 50 dogs (64%) and 11 of 20 cats (55%) showed nodular lesions in the radiographs. In cats, undetected nodules were often accompanied by highly changed lung opacities, resulting in a poor contrast of the lung. In dogs the reasons for a failed detection of lung nodules were relatively equally distributed to several causes. Interestingly, small nodule size itself was not the predominant reason for missing the nodules in radiographs. In general, radiography still plays an important role as a screening method for the detection of nodular lung lesions. However, one needs to be aware, that a quite high percentage of nodular lung changes can be missed in radiographs. The overall detection rate in this study was 61%. Furthermore, we showed that plane radiographs are of poor diagnostic value when concurrent problems exist which lead to increased lung opacity.

Microdome-gooved Gd(2)O(2)S:Tb scintillator for flexible and high resolution digital radiography.

PubMed

Jung, Phill Gu; Lee, Chi Hoon; Bae, Kong Myeong; Lee, Jae Min; Lee, Sang Min; Lim, Chang Hwy; Yun, Seungman; Kim, Ho Kyung; Ko, Jong Soo

2010-07-05

A flexible microdome-grooved Gd(2)O(2)S:Tb scintillator is simulated, fabricated, and characterized for digital radiography applications. According to Monte Carlo simulation results, the dome-grooved structure has a high spatial resolution, which is verified by X-ray image performance of the scintillator. The proposed scintillator has lower X-ray sensitivity than a nonstructured scintillator but almost two times higher spatial resolution at high spatial frequency. Through evaluation of the X-ray performance of the fabricated scintillators, we confirm that the microdome-grooved scintillator can be applied to next-generation flexible digital radiography systems requiring high spatial resolution.

Comparison of craniofacial linear measurements of 20-40 year-old males and females using digital lateral cephalometric radiography in Indonesia

NASA Astrophysics Data System (ADS)

Aurizanti, D.; Suryonegoro, H.; Priaminiarti, M.

2017-08-01

Craniofacial characteristics are one of the sex determination parameters of age after puberty. The aim of this study is to obtain linear measurements using lateral cephalometric radiography of adults aged 20-40 years based on sex in Indonesia. Ten linear craniofacial parameters on 100 digital lateral cephalometric radiographs were measured. Inter-intra observer reliability was tested using Technical Error Measurement. The independent t-test and the Mann-Whitney U test were used to evaluate the significance of the findings. There are significant differences between males and females on 10 of the linear measurements using lateral cephalometric radiography. Lateral cephalometric radiography showed that the linear measurements of 10 cephalometic parameters were higher in males than females, so it can be used to determine sex.

[Wrapping of X-ray Cassette by a Plastic Bag in Portable Radiography: For Infection Prevention and Alleviation of Patient's Discomfort].

PubMed

Nakano, Tsutomu

Portable radiography is available for the patient who is postoperative, severe condition and old. As they have weak immunity, it is important to prevent from hospital infection. Wrapping of 14×14 inch or 14×17 inch X-ray cassette by a plastic (polyethylene) bag a little bit bigger than the cassette was proposed for infection prevention in portable radiography. How to wrap the cassette easily was devised using the sheath of a polyester bag cutting at the bottom. In radiography with the grid, the plastic bag fastens the X-ray grid to the cassette substantially without any other means. In addition, the wrapped cassette, or the cassette with grid covered by the foamed plastic sheet alleviates patient's discomfort.

Quantitative assessment of the equine hoof using digital radiography and magnetic resonance imaging.

PubMed

Grundmann, I N M; Drost, W T; Zekas, L J; Belknap, J K; Garabed, R B; Weisbrode, S E; Parks, A H; Knopp, M V; Maierl, J

2015-09-01

Evaluation of laminitis cases relies on radiographic measurements of the equine foot. Reference values have not been established for all layers of the foot. To establish normal hoof wall and sole measurements using digital radiography (DR) and magnetic resonance imaging (MRI) and to document tissue components present in the dorsal hoof wall and solar layers seen on DR. Prospective observational case-control study. Digital radiography and MRI were performed on 50 cadaver front feet from 25 horses subjected to euthanasia for nonlameness-related reasons. Four observers measured hoof wall (dorsal, lateral and medial) and sole thickness (sagittal, lateral and medial) using DR and magnetic resonance images. One observer repeated the measurements 3 times. Inter- and intraobserver correlation was assessed. Digital radiography and MRI measurements for the normal hoof wall and sole were established. Inter- and intraobserver pairwise Pearson's correlation for DR (r>0.98) and MRI measurements (r>0.99) was excellent. Based on MRI, the less radiopaque layer on DR is comprised of the stratum lamellatum and stratum reticulare. Normal DR and MRI measurements for the hoof wall and sole were established. On DR images, the less radiopaque layer of the foot observed corresponds to the critical tissues injured in laminitis, the strata lamellatum and reticulare. These reference measurements may be used by the clinician to detect soft-tissue changes in the laminitic equine foot and provide a foundation for future research determining changes in these measurements in horses with laminitis. © 2014 EVJ Ltd.

NBS work on neutron resonance radiography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schrack, R.A.

1987-01-01

NBS has been engaged in a wide-ranging program in Neutron Resonance Radiography utilizing both one- and two-dimensional position-sensitive neutron detectors. The ability to perform a position-sensitive assay of up to 16 isotopes in a complex matrix has been demonstrated for a wide variety of sample types, including those with high gamma activity. A major part of the program has been the development and application of the microchannel-plate-based position-sensitive neutron detector. This detector system has high resolution and sensitivity, together with adequate speed of response to be used with neutron time-of-flight techniques. This system has demonstrated the ability to simultaneously imagemore » three isotopes in a sample with no interference.« less

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

NASA Astrophysics Data System (ADS)

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

2004-08-01

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

New developments in flash radiography

NASA Astrophysics Data System (ADS)

Mattsson, Arne

2007-01-01

The paper will review some of the latest developments in flash radiography. A series of multi anode tubes has been developed. These are tubes with several x-ray sources within the same vacuum enclosure. The x-ray sources are closely spaced, to come as close as possible to a single source. The x-ray sources are sequentially pulsed, at times that can be independently chosen. Tubes for voltages in the range 150 - 500 kV, with up to eight x-ray sources, will be described. Combining a multi anode tube with an intensified CCD camera, will make it possible to generate short "x-ray movies". A new flash x-ray control system has been developed. The system is operated from a PC or Laptop. All parameters of a multi channel flash x-ray system can be remotely set and monitored. The system will automatically store important operation parameters.

AXIS: an instrument for imaging Compton radiographs using the Advanced Radiography Capability on the NIF.

PubMed

Hall, G N; Izumi, N; Tommasini, R; Carpenter, A C; Palmer, N E; Zacharias, R; Felker, B; Holder, J P; Allen, F V; Bell, P M; Bradley, D; Montesanti, R; Landen, O L

2014-11-01

Compton radiography is an important diagnostic for Inertial Confinement Fusion (ICF), as it provides a means to measure the density and asymmetries of the DT fuel in an ICF capsule near the time of peak compression. The AXIS instrument (ARC (Advanced Radiography Capability) X-ray Imaging System) is a gated detector in development for the National Ignition Facility (NIF), and will initially be capable of recording two Compton radiographs during a single NIF shot. The principal reason for the development of AXIS is the requirement for significantly improved detection quantum efficiency (DQE) at high x-ray energies. AXIS will be the detector for Compton radiography driven by the ARC laser, which will be used to produce Bremsstrahlung X-ray backlighter sources over the range of 50 keV-200 keV for this purpose. It is expected that AXIS will be capable of recording these high-energy x-rays with a DQE several times greater than other X-ray cameras at NIF, as well as providing a much larger field of view of the imploded capsule. AXIS will therefore provide an image with larger signal-to-noise that will allow the density and distribution of the compressed DT fuel to be measured with significantly greater accuracy as ICF experiments are tuned for ignition.

State of the Art and Development Trends of the Digital Radiography Systems for Cargo Inspection

NASA Astrophysics Data System (ADS)

Udod, V.; Van, J.; Osipov, S.; Chakhlov, S.; Temnik, A.

2016-01-01

Increasing requirements for technical parameters of inspection digital radiography systems are caused by increasing incidences of terrorism, drug trafficking and explosives via variety of transport. These requirements have determined research for new technical solutions that enable to ensure the safety of passengers and cargos in real-time. The main efforts in the analyzed method of testing are aimed at the creation of new and modernization of operated now systems of digital radiography as a whole and their main components and elements in particular. The number of these main components and elements includes sources of X-ray recording systems and transformation of radiometric information as well as algorithms and software that implements these algorithms for processing, visualization and results interpretation of inspection. Recent developments of X-ray units and betatrons used for inspection of small- and large-sized objects that are made from different materials are deserve special attention. The most effective X-ray detectors are a line and a radiometric detector matrix based on various scintillators. The most promising methods among the algorithms of material identification of testing objects are dual-energy methods. The article describes various models of digital radiography systems applied in Russia and abroad to inspection of baggage, containers, vehicles and large trucks.

Digital radiography in general dental practice: a field study.

PubMed

Hellén-Halme, K; Nilsson, M; Petersson, A

2007-07-01

The aim of this study was to conduct a field study to survey the performance of digital radiography and how it was used by dentists in general dental practice. 19 general dental practitioners were visited at their clinics. Ambient light (illuminance) was measured in the rooms where the monitors were placed. Different technical display parameters were noted. Test images and two phantoms--one low-contrast phantom and one line-pair resolution phantom--were used to evaluate the digital system. How the dentists used the enhancement program was investigated by noting which functions were used. Average illuminance in the operating room was 668 lux (range 190-1250 lux). On radiographs of the low-contrast phantom taken at the clinic, the ability to observe the holes decreased as illuminance increased. On average, the "light percentage" initially set on the monitor had to be decreased by 17% and contrast by 10% to optimize the display of the test images. The general dental practitioners used the enhancement programs most often to alter brightness and contrast to obtain the subjectively best image. Large differences between the clinics were noted. Knowledge of how to handle digital equipment in general dental practice should be improved. A calibrated monitor of good quality should be a given priority, as should proper ambient light conditions. There is a need to develop standardized quality controls for digital dental radiography.

Using Digital Radiography To Image Liquid Nitrogen in Voids

NASA Technical Reports Server (NTRS)

Cox, Dwight; Blevins, Elana

2007-01-01

Digital radiography by use of (1) a field-portable x-ray tube that emits low-energy x rays and (2) an electronic imaging x-ray detector has been found to be an effective technique for detecting liquid nitrogen inside voids in thermal-insulation panels. The technique was conceived as a means of investigating cryopumping (including cryoingestion) as a potential cause of loss of thermal insulation foam from space-shuttle external fuel tanks. The technique could just as well be used to investigate cryopumping and cryoingestion in other settings. In images formed by use of low-energy x-rays, one can clearly distinguish between voids filled with liquid nitrogen and those filled with gaseous nitrogen or other gases. Conventional film radiography is of some value, but yields only non-real-time still images that do not show time dependences of levels of liquids in voids. In contrast, the present digital radiographic technique yields a succession of images in real time at a rate of about 10 frames per second. The digitized images can be saved for subsequent analysis to extract data on time dependencies of levels of liquids and, hence, of flow paths and rates of filling and draining. The succession of images also amounts to a real-time motion picture that can be used as a guide to adjustment of test conditions.

Review of medical radiography and tomography with proton beams

NASA Astrophysics Data System (ADS)

Johnson, Robert P.

2018-01-01

The use of hadron beams, especially proton beams, in cancer radiotherapy has expanded rapidly in the past two decades. To fully realize the advantages of hadron therapy over traditional x-ray and gamma-ray therapy requires accurate positioning of the Bragg peak throughout the tumor being treated. A half century ago, suggestions had already been made to use protons themselves to develop images of tumors and surrounding tissue, to be used for treatment planning. The recent global expansion of hadron therapy, coupled with modern advances in computation and particle detection, has led several collaborations around the world to develop prototype detector systems and associated reconstruction codes for proton computed tomography (pCT), as well as more simple proton radiography, with the ultimate intent to use such systems in clinical treatment planning and verification. Recent imaging results of phantoms in hospital proton beams are encouraging, but many technical and programmatic challenges remain to be overcome before pCT scanners will be introduced into clinics. This review introduces hadron therapy and the perceived advantages of pCT and proton radiography for treatment planning, reviews its historical development, and discusses the physics related to proton imaging, the associated experimental and computation issues, the technologies used to attack the problem, contemporary efforts in detector and computational development, and the current status and outlook.

Comparative Study of the Diagnostic Value of Panoramic and Conventional Radiography of the Wrist in Scaphoid Fractures

PubMed Central

Ezoddini Ardakani, Fatemeh; Zangoie Booshehri, Maryam; Banadaki, Seyed Hossein Saeed; Nafisi-Moghadam, Reza

2012-01-01

Background Scaphoid fractures are the most common type of carpal fractures. Objectives The aim of the study was to compare the diagnostic value of panoramic and conventional radiographs of the wrist in scaphoid fractures. Patients and Methods The panoramic and conventional radiographs of 122 patients with acute and chronic wrist trauma were studied. The radiographs were analyzed and examined by two independent radiologist observers; one physician radiologist and one maxillofacial radiologist. The final diagnosis was made by an orthopedic specialist. Kappa test was used for statistical calculations, inter- and intra-observer agreement and correlation between the two techniques. Results Wrist panoramic radiography was more accurate than conventional radiography for ruling out scaphoid fractures. There was an agreement in 85% or more of the cases. Agreement values were higher with better inter and intra observer agreement for panoramic examinations than conventional radiographic examinations. Conclusion The panoramic examination of the wrist is a useful technique for the diagnosis and follow-up of scaphoid fractures. Its use is recommended as a complement to conventional radiography in cases with inconclusive findings. PMID:23599708

Terahertz Imaging and Backscatter Radiography Probability of Detection Study for Space Shuttle Foam Inspections

NASA Technical Reports Server (NTRS)

Ussery, Warren; Johnson, Kenneth; Walker, James; Rummel, Ward

2008-01-01

This slide presentation reviews the use of terahertz imaging and Backscatter Radiography in a probability of detection study of the foam on the external tank (ET) shedding and damaging the shuttle orbiter. Non-destructive Examination (NDE) is performed as one method of preventing critical foam debris during the launch. Conventional NDE methods for inspection of the foam are assessed and the deficiencies are reviewed. Two methods for NDE inspection are reviewed: Backscatter Radiography (BSX) and Terahertz (THZ) Imaging. The purpose of the Probability of Detection (POD) study was to assess performance and reliability of the use of BSX and or THZ as an appropriate NDE method. The study used a test article with inserted defects, and a sample of blanks included to test for false positives. The results of the POD study are reported.

A leaded apron for use in panoramic dental radiography.

PubMed

Whitcher, B L; Gratt, B M; Sickles, E A

1980-05-01

The leaded aprons currently available for use during dental radiography do not protect the thyroid gland from radiation. Conventional aprons may produce artifacts when used with panoramic dental x-ray units. This study measures the dose reduction obtained with an experimental leaded apron designed for use with panoramic dental x-ray units. Skin exposures measured at the thyroid and at the sternum were reduced with the use of the apron. Films produced during the study were free from apron artifacts.

In vitro synchrotron-based radiography of micro-gap formation at the implant-abutment interface of two-piece dental implants.

PubMed

Rack, A; Rack, T; Stiller, M; Riesemeier, H; Zabler, S; Nelson, K

2010-03-01

Micro-gap formation at the implant-abutment interface of two-piece dental implants was investigated in vitro using high-resolution radiography in combination with hard X-ray synchrotron radiation. Images were taken with the specimen under different mechanical loads of up to 100 N. The aim of this investigation was to prove the existence of micro-gaps for implants with conical connections as well as to study the mechanical behavior of the mating zone of conical implants during loading. Synchrotron-based radiography in comparison with classical laboratory radiography yields high spatial resolution in combination with high contrast even when exploiting micro-sized features in highly attenuating objects. The first illustration of a micro-gap which was previously indistinguishable by laboratory methods underlines that the complex micro-mechanical behavior of implants requires further in vitro investigations where synchrotron-based micro-imaging is one of the prerequisites.

Use of incentive spirometry in portable chest radiography.

PubMed

McEntee, Mark F; Houssein, Nariman; Al-azawi, Dhafir

2014-01-01

The degree of lung inflation seen on a chest radiograph is dependent on the point during the patient's respiratory cycle at which the radiographer exposes the image receptor. Exposing the image receptor at the exact peak of inflation can be difficult because of the limited time available in which to capture the inspiratory pause. An incentive spirometer can indicate the moment of peak inhalation. This study tested whether images taken with and without an incentive spirometer display different levels of image quality. This is a paired, prospective, single-blinded study of 30 patients undergoing portable chest radiography. The radiographs were acquired with and without the use of an incentive spirometer. Visual grading analysis was performed using the 1996 European Guidelines on Quality Criteria for Diagnostic Radiographic Images. The mean patient age was 53 years. Sixty images were acquired, 30 with the use of incentive spirometry and 30 without. The most common indication for portable chest radiography was "postlung lobectomy." Scoring on the radiologist's ability to see the sixth rib, spine, trachea, and cardiac border was not affected significantly by the use of incentive spirometry. Use of an incentive spirometer was associated with significant improvement in ability to see the 10th rib (P ≤ .004), vascular pattern (P ≤ .001), retrocardiac lung (P ≤ .013), and the costophrenic angles (P ≤ .005). This study introduces a technique to improve the quality of portable chest radiographs. The use of incentive spirometry improved inspiratory depth and image quality for portable chest radiographs.

Medical radiography examinations and carcinogenic effects.

PubMed

Domina, E A

2014-09-01

The purpose of the review was the synthesis of the literature data and the results of our radiobiological (biodosimetric) research on the development of radiation-associated tumors as a result of medical radiography (X-ray) diagnostic. Medical X-ray examinations contribute the most to the excess of radiation exposure of the population, much of which is subject to examination to diagnose the underlying disease, the dynamic observation of the patient during treatment, the research of related deseases, and preventative examinations. The review provides arguments for the necessity of developing a more balanced indication for preventative radiological examination of the population in the aftermath of radio-ecological crisis caused by the Chornobyl accident, taking into account the likelihood of radiation carcinogenesis. The problems and tasks of biological (cytogenetic) dosimetry in radiology are formulated. E. A. Domina.

Infection control procedures used in conjunction with computed dental radiography.

PubMed

Hubar, J S; Gardiner, D M

2000-10-01

Infection control guidelines for dental radiography have been modified since 1986, when the American Dental Association and the Centers for Disease Control and Prevention supported the concept of "universal blood and body fluid precautions." With the introduction of computed digital radiography, hardware manufacturers recommend that alternative infection control techniques are necessary to prevent potential damage to the digital x-ray sensors placed inside the patient's mouth. Thirty first-year dental hygiene students were asked to insert and remove a Schick CDR number 2 size intraoral digital x-ray sensor into modified Rinn XCP bitewing bite blocks and a modified Rinn Snap-a-ray five times with each of the recommended infection control covers. Reduced rates of cross contamination are possible if the plastic barrier envelope has an additional latex finger cot stretched over it and the x-ray sensor. Sole usage of a latex finger cot will result in a reduced incidence of contamination, but still not to acceptable levels. However, a plastic barrier envelope placed over the x-ray sensor and over the modified XCP bite block together or a covered sensor in a Snap-a-ray under normal conditions does not result in a perforation and is least likely to result in cross contamination.

[Radiation exposure of children in pediatric radiology. Part 5: organ doses in chest radiography].

PubMed

Seidenbusch, M C; Schneider, K

2009-05-01

Reconstruction of organ doses of selected organs and tissues from radiographic settings and exposure data collected during chest X-ray examinations of children of various age groups performed in Dr. von Hauner's Kinderspital (children's hospital of the University of Munich, DvHK) between 1976 and 2007. The dosimetric data of all X-ray examinations performed since 1976 at DvHK were stored electronically in a database. After 30 years of data collection, the database now includes 305 107 radiological examinations (radiographs and fluoroscopies), especially 119 150 chest radiographs of all age groups. Reconstruction of organ doses in 40 organs and tissues in X-ray examinations of the chest was performed based on the conversion factor concept. The radiation exposure of organs in projection radiography is determined by the exact site of the organs relative to the edges of the X-ray field and the beam direction of X-rays. Optimal collimation in chest radiography can reduce the exposure of organs located at the periphery of the X-ray field, e. g. thyroid gland, stomach and partially the liver, by a factor of 2 to 3, while organs located in the center of the X-ray-field, e. g. thymus, breasts, lungs, esophagus and red bone marrow, are not affected by exact collimation. The high frequency of the roentgen examination of the chest in early age groups increases the collective radiation burden to radiosensitive organs. Therefore, radiation protection of the patient during chest radiographies remains of great importance.

MO-G-18A-01: Radiation Dose Reducing Strategies in CT, Fluoroscopy and Radiography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahesh, M; Gingold, E; Jones, A

2014-06-15

Advances in medical x-ray imaging have provided significant benefits to patient care. According to NCRP 160, there are more than 400 million x-ray procedures performed annually in the United States alone that contributes to nearly half of all the radiation exposure to the US population. Similar growth trends in medical x-ray imaging are observed worldwide. Apparent increase in number of medical x-ray imaging procedures, new protocols and the associated radiation dose and risk has drawn considerable attention. This has led to a number of technological innovations such as tube current modulation, iterative reconstruction algorithms, dose alerts, dose displays, flat panelmore » digital detectors, high efficient digital detectors, storage phosphor radiography, variable filters, etc. that are enabling users to acquire medical x-ray images at a much lower radiation dose. Along with these, there are number of radiation dose optimization strategies that users can adapt to effectively lower radiation dose in medical x-ray procedures. The main objectives of this SAM course are to provide information and how to implement the various radiation dose optimization strategies in CT, Fluoroscopy and Radiography. Learning Objectives: To update impact of technological advances on dose optimization in medical imaging. To identify radiation optimization strategies in computed tomography. To describe strategies for configuring fluoroscopic equipment that yields optimal images at reasonable radiation dose. To assess ways to configure digital radiography systems and recommend ways to improve image quality at optimal dose.« less

Industrial Application Experiments on the Neutron Imaging Instrument DINGO

NASA Astrophysics Data System (ADS)

Garbe, Ulf; Ahuja, Yogita; Ibrahim, Ralph; Li, Huijun; Aldridge, Laurie; Salvemini, Filomena; Paradowska, Anna Ziara

The new neutron radiography / tomography / imaging instrument DINGO is operational since October 2014 to support the area of neutron imaging research at ANSTO. The instrument is designed for a diverse community in areas like defense, industrial, cultural heritage and archaeology applications. In the field of industrial application it provides a useful tool for studying cracking and defects in concrete or other structural material. Since being operational we gathered experience with industrial applications and commercial customers demanding beam time on DINGO. The instrument is a high flux facility with is 5.3 × 107 [n/(cm2s)] (confirmed by gold foil activation) for an L/D of approximately 500 at HB-2. A special feature of DINGO is the in-pile collimator position in front of the main shutter at HB-2. The collimator offers two pinholes with a possible L/D of 500 and 1000. A secondary collimator separates the two beams by blocking one and positions another aperture for the other beam. The neutron beam size can be adjusted to the sample size from 50 × 50 mm2 to 200 × 200 mm2 with a resulting pixel size from 27 μm to ∼100 μm. The whole instrument operates in two different positions, one for high resolution and one for high speed. We would like to present our first experience with commercial customers, scientific proposals with industrial applications and how to be customer ready.

Application of Terahertz Imaging and Backscatter Radiography to Space Shuttle Foam Inspection

NASA Technical Reports Server (NTRS)

Ussery, Warren

2008-01-01

Two state of the art technologies have been developed for External Fuel Tank foam inspections. Results of POD tests have shown Backscatter Radiography and Terahertz imaging detect critical defects with no false positive issue. These techniques are currently in use on the External Tank program as one component in the foam quality assurance program.

Can routine chest radiography be used to diagnose mild COPD? A nested case-control study.

PubMed

den Harder, A M; Snoek, A M; Leiner, T; Suyker, W J; de Heer, L M; Budde, R P J; Lammers, J W J; de Jong, P A; Gondrie, M J A

2017-07-01

To determine whether mild stage chronic obstructive pulmonary disease (COPD) can be detected on chest radiography without substantial overdiagnosis. A retrospective nested case-control study (case:control, 1:1) was performed in 783 patients scheduled for cardiothoracic surgery who underwent both spirometry and a chest radiograph preoperative. Diagnostic accuracy of chest radiography for diagnosing mild COPD was investigated using objective measurements and overall appearance specific for COPD on chest radiography. Inter-observer variability was investigated and variables with a kappa >0.40 as well as baseline characteristics were used to make a diagnostic model which was aimed at achieving a high positive predictive value (PPV). Twenty percent (155/783) had COPD. The PPV of overall appearance specific for COPD alone was low (37-55%). Factors in the diagnostic model were age, type of surgery, gender, distance of the right diaphragm apex to the first rib, retrosternal space, sternodiaphragmatic angle, maximum height right diaphragm (lateral view) and subjective impression of COPD (using both views). The model resulted in a PPV of 100%, negative predictive value (NPV) of 82%, sensitivity of 10% and specificity of 100% with an area under the curve of 0.811. Detection of mild COPD without substantial overdiagnosis was not feasible on chest radiographs in our cohort. Copyright © 2017 Elsevier B.V. All rights reserved.

AXIS: An instrument for imaging Compton radiographs using the Advanced Radiography Capability on the NIF

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hall, G. N., E-mail: hall98@llnl.gov; Izumi, N.; Tommasini, R.

2014-11-15

Compton radiography is an important diagnostic for Inertial Confinement Fusion (ICF), as it provides a means to measure the density and asymmetries of the DT fuel in an ICF capsule near the time of peak compression. The AXIS instrument (ARC (Advanced Radiography Capability) X-ray Imaging System) is a gated detector in development for the National Ignition Facility (NIF), and will initially be capable of recording two Compton radiographs during a single NIF shot. The principal reason for the development of AXIS is the requirement for significantly improved detection quantum efficiency (DQE) at high x-ray energies. AXIS will be the detectormore » for Compton radiography driven by the ARC laser, which will be used to produce Bremsstrahlung X-ray backlighter sources over the range of 50 keV–200 keV for this purpose. It is expected that AXIS will be capable of recording these high-energy x-rays with a DQE several times greater than other X-ray cameras at NIF, as well as providing a much larger field of view of the imploded capsule. AXIS will therefore provide an image with larger signal-to-noise that will allow the density and distribution of the compressed DT fuel to be measured with significantly greater accuracy as ICF experiments are tuned for ignition.« less

Interior Temperature Measurement Using Curved Mercury Capillary Sensor Based on X-ray Radiography

NASA Astrophysics Data System (ADS)

Chen, Shuyue; Jiang, Xing; Lu, Guirong

2017-07-01

A method was presented for measuring the interior temperature of objects using a curved mercury capillary sensor based on X-ray radiography. The sensor is composed of a mercury bubble, a capillary and a fixed support. X-ray digital radiography was employed to capture image of the mercury column in the capillary, and a temperature control system was designed for the sensor calibration. We adopted livewire algorithms and mathematical morphology to calculate the mercury length. A measurement model relating mercury length to temperature was established, and the measurement uncertainty associated with the mercury column length and the linear model fitted by least-square method were analyzed. To verify the system, the interior temperature measurement of an autoclave, which is totally closed, was taken from 29.53°C to 67.34°C. The experiment results show that the response of the system is approximately linear with an uncertainty of maximum 0.79°C. This technique provides a new approach to measure interior temperature of objects.

X-Ray Thomson Scattering and Radiography from Spherical Implosions on the OMEGA Laser

NASA Astrophysics Data System (ADS)

Saunders, A. M.; Laziki-Jenei, A.; Doeppner, T.; Landen, O. L.; MacDonald, M.; Nilsen, J.; Swift, D.; Falcone, R. W.

2017-10-01

X-ray Thomson scattering (XRTS) is an experimental technique that directly probes the physics of warm dense matter by measuring electron density, electron temperature, and ionization state. XRTS in combination with x-ray radiography offers a unique ability to measure an absolute equation of state (EOS) from material under compression. Recent experiments highlight uncertainties in EOS models and the predicted ionization of compressed matter, suggesting more validation of models is needed. We present XRTS and x-ray radiography measurements taken at the OMEGA Laser Facility from directly-driven solid carbon spheres at densities on the order of 1x1024 g cm-3 and temperatures on the order of 30 eV. The results shed light on the equations of state of matter under compression. This work performed under auspices of the US Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and under the Stewardship Science Graduate Fellowship, Grant Number DE- NA0002135.

Thorium-uranium fission radiography

NASA Technical Reports Server (NTRS)

Haines, E. L.; Weiss, J. R.; Burnett, D. S.; Woolum, D. S.

1976-01-01

Results are described for studies designed to develop routine methods for in-situ measurement of the abundance of Th and U on a microscale in heterogeneous samples, especially rocks, using the secondary high-energy neutron flux developed when the 650 MeV proton beam of an accelerator is stopped in a 42 x 42 cm diam Cu cylinder. Irradiations were performed at three different locations in a rabbit tube in the beam stop area, and thick metal foils of Bi, Th, and natural U as well as polished silicate glasses of known U and Th contents were used as targets and were placed in contact with mica which served as a fission track detector. In many cases both bare and Cd-covered detectors were exposed. The exposed mica samples were etched in 48% HF and the fission tracks counted by conventional transmitted light microscopy. Relative fission cross sections are examined, along with absolute Th track production rates, interaction tracks, and a comparison of measured and calculated fission rates. The practicality of fast neutron radiography revealed by experiments to data is discussed primarily for Th/U measurements, and mixtures of other fissionable nuclei are briefly considered.

MRI Before Radiography for Patients With New Shoulder Conditions.

PubMed

Small, Kirstin M; Rybicki, Frank J; Miller, Lindsay R; Daniels, Stephen D; Higgins, Laurence D

2017-06-01

To assess the patterns of Appropriate Criteria application among orthopedic specialists and other fields of medicine for use of MRI and radiography and the subsequent necessity for surgical intervention. The hospital electronic medical record was used to identify all shoulder MRI studies at a single large urban teaching hospital between January 2, 2011, and June 30, 2011. For each study, variables collected included ordering department, patient age, patient gender, patient's self-reported race/ethnicity, whether the patient obtained surgery for an issue related to the MRI diagnosis, the type of MRI ordered, the date of pain onset, the date of x-ray (if any), and the date of the MRI. A total of 475 patients who underwent shoulder MRI were included in our study. We found significant associations between a patient having had a prior x-ray and ordering department (P < .0001), male gender (P = .0005), and subjects who had subsequent surgery (P = .0006). Neither age nor race and ethnicity had an influence on x-ray before MRI. Orthopedic specialists ordering MRIs had the highest percentage of patients undergo subsequent surgery (33.3%) compared with the second-most, primary care (18.4%), and all other ordering departments (P = .0009). Detailed analysis suggests that providers who do not have specific training in shoulder pathology should consider consultation with an orthopedic surgeon before ordering shoulder MRI for patients who may need additional imaging after radiography. Copyright © 2017 American College of Radiology. Published by Elsevier Inc. All rights reserved.

10 CFR 34.101 - Notifications.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 1 2012-01-01 2012-01-01 false Notifications. 34.101 Section 34.101 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL... overexposure submitted under 10 CFR 20.2203 which involves failure of safety components of radiography...

10 CFR 34.101 - Notifications.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 1 2014-01-01 2014-01-01 false Notifications. 34.101 Section 34.101 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL... overexposure submitted under 10 CFR 20.2203 which involves failure of safety components of radiography...

10 CFR 34.101 - Notifications.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 1 2013-01-01 2013-01-01 false Notifications. 34.101 Section 34.101 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL... overexposure submitted under 10 CFR 20.2203 which involves failure of safety components of radiography...

10 CFR 34.101 - Notifications.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 1 2011-01-01 2011-01-01 false Notifications. 34.101 Section 34.101 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL... overexposure submitted under 10 CFR 20.2203 which involves failure of safety components of radiography...

FINAL SCIENTIFIC REPORT - PROTON RADIOGRAPHY: CROSS SECTION MEASUREMENTS AND DETECTOR DEVELOPMENT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Longo, Michael J.; Gustafson, H. Richard.; Rajaram, Durga

2007-05-11

Proton radiography offers significant advantages over conventional X-ray radiography, including the capability of looking into thick, dense materials, better contrast for a wide range of materials, sensitivity to different materials of similar density, and better resolution because of the ability to focus beams. In order to achieve this capability it is crucial to understand the background due to neutrons and photons and to develop techniques to reduce it to tolerable levels. The physics goal of this project is to measure forward production of neutrons and photons produced by high-energy proton beams striking a variety of targets. This work is beingmore » carried out in conjunction with the Fermilab Experiment 907 (MIPP) collaboration including physicists from Lawrence Livermore Laboratory. Our group is responsible for the E907 forward neu-tron/photon calorimeters. These are the only detectors in the experiment that provide informa-tion on neutrons and photons. We are taking a leading role in obtaining and analyzing the for-ward production data and in developing an optimal detector for proton radiography. With the support of our Stewardship Science Academic Alliances grant, we were able to design, build, and commission the calorimeters on budget and ahead of schedule. E-907 officially started physics running at Fermilab in January 2005, and data taking continued through February 2006. Data were taken on a range of targets, from liquid hydrogen to uranium, at beam energies from 5 GeV/c to 120 GeV/c. The analysis of the data is challenging because data from many different detector systems must be understood and merged and over 31 million events were accumulated. Our recent efforts have been devoted to the calibration of the neutron and photon detectors, to track and shower reconstruction, identification of forward-going neutrons, and simulation of the calorimeters in a Monte Carlo. Reconstruction of the data with improved tracking is underway.« less

Digital radiography and caries diagnosis.

PubMed

Wenzel, A

1998-01-01

Direct digital acquisition of intra-oral radiographs has been possible only in the last decade. Several studies have shown that, theoretically, there are a number of advantages of direct digital radiography compared with conventional film. Laboratory as well as controlled clinical studies are needed to determine whether new digital imaging systems alter diagnosis, treatment and prognosis compared with conventional methods. Most studies so far have evaluated their diagnostic performance only in laboratory settings. This review concentrates on what evidence we have for the diagnostic efficacy of digital systems for caries detection. Digital systems are compared with film and those studies which have evaluated the effects on diagnostic accuracy of contrast and edge enhancement, image size, variations in radiation dose and image compression are reviewed together with the use of automated image analysis for caries diagnosis. Digital intra-oral radiographic systems seem to be as accurate as the currently available dental films for the detection of caries. Sensitivities are relatively high (0.6-0.8) for detection of occlusal lesions into dentine with false positive fractions of 5-10%. A radiolucency in dentine is recognised as a good predictor for demineralisation. Radiography is of no value for the detection of initial (enamel) occlusal lesions. For detection of approximal dentinal lesions, sensitivities, specificities as well as the predictive values are fair, but are very poor for lesions known to be confined to enamel. Very little documented information exists, however, on the utilization of digital systems in the clinic. It is not known whether dose is actually reduced with the storage phosphor system, or whether collimator size is adjusted to fit sensor size in the CCD-based systems. There is no evidence that the number of retakes have been reduced. It is not known how many images are needed with the various CCD systems when compared with a conventional bitewing

Detection of early osteoarthritis in the centrodistal joints of Icelandic horses: Evaluation of radiography and low-field magnetic resonance imaging.

PubMed

Ley, C J; Björnsdóttir, S; Ekman, S; Boyde, A; Hansson, K

2016-01-01

Validated noninvasive detection methods for early osteoarthritis (OA) are required for OA prevention and early intervention treatment strategies. To evaluate radiography and low-field magnetic resonance imaging (MRI) for the detection of early stage OA osteochondral lesions in equine centrodistal joints using microscopy as the reference standard. Prospective imaging of live horses and imaging and microscopy of cadaver tarsal joints. Centrodistal (distal intertarsal) joints of 38 Icelandic research horses aged 27-29 months were radiographed. Horses were subjected to euthanasia approximately 2 months later and cadaver joints examined with low-field MRI. Osteochondral joint specimens were classified as negative or positive for OA using light microscopy histology or scanning electron microscopy. Radiographs and MRIs were evaluated for osteochondral lesions and results compared with microscopy. Forty-two joints were classified OA positive with microscopy. Associations were detected between microscopic OA and the radiography lesion categories; mineralisation front defect (P<0.0001), joint margin lesion (P<0.0001), central osteophyte (P = 0.03) and the low-field MRI lesion categories; mineralisation front defect (P = 0.01), joint margin lesion (P = 0.02) and articular cartilage lesion (P = 0.0003). The most frequent lesion category detected in microscopic OA positive joints was the mineralisation front defect in radiographs (28/42 OA positive joints, specificity 97%, sensitivity 67%). No significant differences were detected between the sensitivity and specificity of radiography and low-field MRI pooled lesion categories, but radiography was often superior when individual lesion categories were compared. Early stage centrodistal joint OA changes may be detected with radiography and low-field MRI. Detection of mineralisation front defects in radiographs may be a useful screening method for detection of early OA in centrodistal joints of young Icelandic horses. © 2015 EVJ

Follow-Up Survey of the 1988-1989 Radiography Graduates of Middlesex Community College.

ERIC Educational Resources Information Center

Spence, Weymouth

A graduate follow-up survey evaluated student outcomes for the radiography program at Middlesex Community College/Middlesex Memorial Hospital (Connecticut). The program prepares students for entry-level employment as radiographers. The questionnaire, based on input from program officials and respondents, was mailed to 14 1988 and 1989 graduates.…

The new neutron radiography/tomography/imaging station DINGO at OPAL

NASA Astrophysics Data System (ADS)

Garbe, U.; Randall, T.; Hughes, C.

2011-09-01

A new neutron imaging instrument will be built to support the area of neutron imaging research (neutron radiography/tomography) at ANSTO. The instrument will be designed for an international user community and for routine quality control for defence, industrial, mining, space and aircraft applications. It will also be a useful tool for assessing oil and water flow in sedimentary rock reservoirs (like the North West Shelf), assessing water damage in aircraft components, and the study of hydrogen distribution and cracking in steel. The instrument is planned to be completed by the end of June 2013 and is currently in the design stage. The usable neutron flux is mainly determined by the neutron source, but it also depends on the instrument position and the resolution. The designated instrument position for DINGO is the beam port HB-2 in the reactor hall. The estimated flux for an L/ D of approximately 250 at HB-2 is calculated by Mcstas simulation in a range of 4.75×10 7 n/cm 2 s, which is in the same range of other facilities like ANSTARES (FRM II; Schillinger et al., 2004 [1]) or BT2 (NIST; Hussey et al., 2005 [2]). A special feature of DINGO is the in-pile collimator place in front of the main shutter at HB-2. The collimator offers two pinholes with a possible L/ D of 250 and 1000. A secondary collimator will separate the two beams and block one. The whole instrument will operate in two different positions, one for high resolution and the other for high speed.

Diagnostic value of panoramic radiography in predicting inferior alveolar nerve injury after mandibular third molar extraction: a meta-analysis.

PubMed

Liu, W; Yin, W; Zhang, R; Li, J; Zheng, Y

2015-06-01

The aim of this study was to evaluate the predictive value of panoramic radiography on inferior alveolar nerve (IAN) injury after extraction of the mandibular third molar. Relevant studies up to 1 June 2014 that discussed the association of panoramic radiography signs and post-mandibular third molar extraction IAN injury were systematically retrieved from the databases of PubMed, Embase, Springerlink, Web of Science and Cochrane library. The effect size of pooled sensitivity, specificity, positive likelihood ratios (PLR), negative likelihood ratios (NLR) and diagnostic odds ratio (DOR) with their 95% confidence intervals (CI) were statistically analysed with Meta-disc 1.4 software. Nine articles were included in this meta-analysis. The pooled estimates of sensitivity and specificity were 0.56 (95% CI: 0.50-0.61) and 0.86 (95% CI: 0.84-0.87), respectively. The overall PLR was 3.46 (95% CI: 2.02-5.92) and overall NLR was 0.58 (95% CI: 0.45-0.73). The pooled estimate of DOR was 6.49 (95% CI: 2.92-14.44). The area under the summary receiver operating characteristic curve was 0.7143 ± 0.0604. The meta-analysis indicated that interpretation of panoramic radiography based on darkening of the root had a high specificity in predicting IAN injury after mandibular third molar extraction. However, the ability of this panoramic radiography marker to detect true positive IAN injury was not satisfactory. © 2015 Australian Dental Association.

ACR Appropriateness Criteria® Routine Chest Radiography.

PubMed

McComb, Barbara L; Chung, Jonathan H; Crabtree, Traves D; Heitkamp, Darel E; Iannettoni, Mark D; Jokerst, Clinton; Saleh, Anthony G; Shah, Rakesh D; Steiner, Robert M; Mohammed, Tan-Lucien H; Ravenel, James G

2016-03-01

Chest radiographs are sometimes taken before surgeries and interventional procedures on hospital admissions and outpatients. This manuscript summarizes the American College of Radiology review of the literature and recommendations on routinely performed chest radiographies in these settings. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Nonportable computed radiography of the chest--radiologists' acceptance

NASA Astrophysics Data System (ADS)

Gennari, Rose C.; Gur, David; Miketic, Linda M.; Campbell, William L.; Oliver, James H., III; Plunkett, Michael B.

1994-04-01

Following a large ROC study to assess diagnostic accuracy of PA chest computed radiography (CR) images displayed in a variety of formats, we asked nine experienced radiologists to subjectively assess their acceptance of and preferences for display modes in primary diagnosis of erect PA chest images. Our results indicate that radiologists felt somewhat less comfortable interpreting CR images displayed on either laser-printed films or workstations as compared to conventional films. The use of four minified images were thought to somewhat decrease diagnostic confidence, as well as to increase the time of interpretation. The reverse mode (black bone) images increased radiologists' confidence level in the detection of soft tissue abnormalities.

Towards optimization in digital chest radiography using Monte Carlo modelling

NASA Astrophysics Data System (ADS)

Ullman, Gustaf; Sandborg, Michael; Dance, David R.; Hunt, Roger A.; Alm Carlsson, Gudrun

2006-06-01

A Monte Carlo based computer model of the x-ray imaging system was used to investigate how various image quality parameters of interest in chest PA radiography and the effective dose E vary with tube voltage (90-150 kV), additional copper filtration (0-0.5 mm), anti-scatter method (grid ratios 8-16 and air gap lengths 20-40 cm) and patient thickness (20-28 cm) in a computed radiography (CR) system. Calculated quantities were normalized to a fixed value of air kerma (5.0 µGy) at the automatic exposure control chambers. Soft-tissue nodules were positioned at different locations in the anatomy and calcifications in the apical region. The signal-to-noise ratio, SNR, of the nodules and the nodule contrast relative to the contrast of bone (C/CB) as well as relative to the dynamic range in the image (Crel) were used as image quality measures. In all anatomical regions, except in the densest regions in the thickest patients, the air gap technique provides higher SNR and contrast ratios than the grid technique and at a lower effective dose E. Choice of tube voltage depends on whether quantum noise (SNR) or the contrast ratios are most relevant for the diagnostic task. SNR increases with decreasing tube voltage while C/CB increases with increasing tube voltage.

Imaging of plantar fascia disorders: findings on plain radiography, ultrasound and magnetic resonance imaging.

PubMed

Draghi, Ferdinando; Gitto, Salvatore; Bortolotto, Chandra; Draghi, Anna Guja; Ori Belometti, Gioia

2017-02-01

Plantar fascia (PF) disorders commonly cause heel pain and disability in the general population. Imaging is often required to confirm diagnosis. This review article aims to provide simple and systematic guidelines for imaging assessment of PF disease, focussing on key findings detectable on plain radiography, ultrasound and magnetic resonance imaging (MRI). Sonographic characteristics of plantar fasciitis include PF thickening, loss of fibrillar structure, perifascial collections, calcifications and hyperaemia on Doppler imaging. Thickening and signal changes in the PF as well as oedema of adjacent soft tissues and bone marrow can be assessed on MRI. Radiographic findings of plantar fasciitis include PF thickening, cortical irregularities and abnormalities in the fat pad located deep below the PF. Plantar fibromatosis appears as well-demarcated, nodular thickenings that are iso-hypoechoic on ultrasound and show low-signal intensity on MRI. PF tears present with partial or complete fibre interruption on both ultrasound and MRI. Imaging description of further PF disorders, including xanthoma, diabetic fascial disease, foreign-body reactions and plantar infections, is detailed in the main text. Ultrasound and MRI should be considered as first- and second-line modalities for assessment of PF disorders, respectively. Indirect findings of PF disease can be ruled out on plain radiography. Teaching Points • PF disorders commonly cause heel pain and disability in the general population.• Imaging is often required to confirm diagnosis or reveal concomitant injuries.• Ultrasound and MRI respectively represent the first- and second-line modalities for diagnosis.• Indirect findings of PF disease can be ruled out on plain radiography.

Visualization of oil behavior in a small 4-cycle engine with electrical motoring by neutron radiography

NASA Astrophysics Data System (ADS)

Nakamura, M.; Sugimoto, K.; Asano, H.; Murakawa, H.; Takenaka, N.; Mochiki, K.

2009-06-01

Neutron radiography is suitable for the visualization of liquid behavior in a metallic machine. Observation of oil behavior in a small 4-cycle engine on operating was carried out by using the neutron radiography facility at JRR-3 in JAEA. The engine was not fired but operated by an electrical motor. Movies were taken by a neutron image intensifier with a color CCD camera of 8-bit resolution, 30 frames/s and 640×480 pixels developed by Toshiba Corp. The engine was placed on a turn table and was rotated, so the movie could be taken from any angle. Numbers of revolution of the engine were changed from 260 to 1200 rpm. Visualized images of the mechanism and the oil behavior in the engine were obtained.

[Development of image quality assurance support system using image recognition technology in radiography in lacked images of chest and abdomen].

PubMed

Shibuya, Toru; Kato, Kyouichi; Eshima, Hidekazu; Sumi, Shinichirou; Kubo, Tadashi; Ishida, Hideki; Nakazawa, Yasuo

2012-01-01

In order to provide a precise radiography for diagnosis, it is required that we avoid radiography with defects by having enough evaluation. Conventionally, evaluation was performed only by observation of a radiological technologist (RT). The evaluation support system was developed for providing a high quality assurance without depending on RT observation only. The evaluation support system, called as the Image Quality Assurance Support System (IQASS), is characterized in that "image recognition technology" for the purpose of diagnostic radiography of chest and abdomen areas. The technique of the system used in this study. Of the 259 samples of posterior-anterior (AP) chest, lateral chest, and upright abdominal x-rays, the sensitivity and specificity was 93.1% and 91.8% in the chest AP, 93.3% and 93.6% in the chest lateral, and 95.0% and 93.8% in the upright abdominal x-rays. In the light of these results, it is suggested that AIQAS could be applied to practical usage for the RT.

a Single-Exposure Dual-Energy Computed Radiography Technique for Improved Nodule Detection and Classification in Chest Imaging

NASA Astrophysics Data System (ADS)

Zink, Frank Edward

The detection and classification of pulmonary nodules is of great interest in chest radiography. Nodules are often indicative of primary cancer, and their detection is particularly important in asymptomatic patients. The ability to classify nodules as calcified or non-calcified is important because calcification is a positive indicator that the nodule is benign. Dual-energy methods offer the potential to improve both the detection and classification of nodules by allowing the formation of material-selective images. Tissue-selective images can improve detection by virtue of the elimination of obscuring rib structure. Bone -selective images are essentially calcium images, allowing classification of the nodule. A dual-energy technique is introduced which uses a computed radiography system to acquire dual-energy chest radiographs in a single-exposure. All aspects of the dual-energy technique are described, with particular emphasis on scatter-correction, beam-hardening correction, and noise-reduction algorithms. The adaptive noise-reduction algorithm employed improves material-selective signal-to-noise ratio by up to a factor of seven with minimal sacrifice in selectivity. A clinical comparison study is described, undertaken to compare the dual-energy technique to conventional chest radiography for the tasks of nodule detection and classification. Observer performance data were collected using the Free Response Observer Characteristic (FROC) method and the bi-normal Alternative FROC (AFROC) performance model. Results of the comparison study, analyzed using two common multiple observer statistical models, showed that the dual-energy technique was superior to conventional chest radiography for detection of nodules at a statistically significant level (p < .05). Discussion of the comparison study emphasizes the unique combination of data collection and analysis techniques employed, as well as the limitations of comparison techniques in the larger context of technology

Digital radiography with computerized conventional monitors compared to medical monitors in vertical root fracture diagnosis.

PubMed

Tofangchiha, Maryam; Adel, Mamak; Bakhshi, Mahin; Esfehani, Mahsa; Nazeman, Pantea; Ghorbani Elizeyi, Mojgan; Javadi, Amir

2013-01-01

Vertical root fracture (VRF) is a complication which is chiefly diagnosed radiographically. Recently, film-based radiography has been substituted with digital radiography. At the moment, there is a wide range of monitors available in the market for viewing digital images. The present study aims to compare the diagnostic accuracy, sensitivity and specificity of medical and conventional monitors in detection of vertical root fractures. In this in vitro study 228 extracted single-rooted human teeth were endodontically treated. Vertical root fractures were induced in 114 samples. The teeth were imaged by a digital charge-coupled device radiography using parallel technique. The images were evaluated by a radiologist and an endodontist on two medical and conventional liquid-crystal display (LCD) monitors twice. Z-test was used to analyze the sensitivity, accuracy and specificity of each monitor. Significance level was set at 0.05. Inter and intra observer agreements were calculated by Cohen's kappa. Accuracy, specificity and sensitivity for conventional monitor were calculated as 67.5%, 72%, 62.5% respectively; and data for medical grade monitor were 67.5%, 66.5% and 68% respectively. Statistical analysis showed no significant differences in detecting VRF between the two techniques. Inter-observer agreement for conventional and medical monitor was 0.47 and 0.55 respectively (moderate). Intra-observer agreement was 0.78 for medical monitor and 0.87 for conventional one (substantial). The type of monitor does not influence diagnosis of vertical root fractures.

High-speed, two-dimensional synchrotron white-beam x-ray radiography of spray breakup and atomization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Halls, Benjamin R.; Radke, Christopher D.; Reuter, Benjamin J.

High-speed, two-dimensional synchrotron x-ray radiography and phase-contrast imaging are demonstrated in propulsion sprays. Measurements are performed at the 7-BM beamline at the Advanced Photon Source user facility at Argonne National Laboratory using a recently developed broadband x-ray white beam. This novel enhancement allows for high speed, high fidelity x-ray imaging for the community at large. Quantitative path-integrated liquid distributions and spatio-temporal dynamics of the sprays were imaged with a LuAG:Ce scintillator optically coupled to a high-speed CMOS camera. Images are collected with a microscope objective at frame rates of 20 kHz and with a macro lens at 120 kHz, achievingmore » spatial resolutions of 12 μm and 65 μm, respectively. Imaging with and without potassium iodide (KI) as a contrast-enhancing agent is compared, and the effects of broadband attenuation and spatial beam characteristics are determined through modeling and experimental calibration. In addition, phase contrast is used to differentiate liquid streams with varying concentrations of KI. The experimental approach is applied to different spray conditions, including quantitative measurements of mass distribution during primary atomization and qualitative visualization of turbulent binary fluid mixing. High-speed, two-dimensional synchrotron white-beam x-ray radiography of spray breakup and atomization. Available from: https://www.researchgate.net/publication/312567827_High-speed_two-dimensional_synchrotron_white-beam_x-ray_radiography_of_spray_breakup_and_atomization [accessed Aug 31, 2017].« less

Food consumption and digestion time estimation of spotted scat, Scatophagus argus, using X-radiography technique

NASA Astrophysics Data System (ADS)

Hashim, Marina; Abidin, Diana Atiqah Zainal; Das, Simon K.; Ghaffar, Mazlan Abd.

2014-09-01

The present study was conducted to investigate the food consumption pattern and gastric emptying time using x-radiography technique in scats fish, Scatophagus argus feeding to satiation in laboratory conditions. Prior to feeding experiment, fish of various sizes were examined their stomach volume, using freshly prepared stomachs ligatured at the tips of the burret, where the maximum amount of distilled water collected in the stomach were measured (ml). Stomach volume is correlated with maximum food intake (Smax) and it can estimate the maximum stomach distension by allometric model i.e volume=0.0000089W2.93. Gastric emptying time was estimated using a qualitative X-radiography technique, where the fish of various sizes were fed to satiation at different time since feeding. All the experimental fish was feed into satiation using radio-opaque barium sulphate (BaSO4) paste injected in the wet shrimp in proportion to the body weight. The BaSO4 was found suitable to track the movement of feed/prey in the stomach over time and gastric emptying time of scats fish can be estimated. The results of qualitative X-Radiography observation of gastric motility, showed the fish (200 gm) that fed to maximum satiation meal (circa 11 gm) completely emptied their stomach within 30 - 36 hrs. The results of the present study will provide the first baseline information on the stomach volume, gastric emptying of scats fish in captivity.

The natural history of the anterior knee instability by stress radiography

PubMed Central

de Rezende, Márcia Uchôa; Hernandez, Arnaldo José; Camanho, Gilberto Luis

2014-01-01

OBJECTIVE: To analyze the anteroposterior displacement of the knee by means of stress radiography in individuals with unilateral anterior knee instability and relate to time of instability. METHODS: Sixty individuals with intact knees (control group) and 125 patients with unilateral anterior instability (AI group) agreed to participate in the study. Gender, age, weight, height, age at injury, time between injury and testing, and surgical findings are studied. Both groups are submitted to anterior and posterior stress radiographies of both knees. Anterior (ADD) and posterior displacement difference (PDD) were calculated between sides. RESULTS: In the control group ADD and PDD are in average, zero, whereas in the AI group ADD averaged 9.8mm and PDD, 1.92mm. Gender, age, weight, height, age at trauma and presence of menisci's lesions do not intervene in the values of ADD and PDD. Meniscal injuries increase with time. ADD and PDD do not relate with the presence or absence of associated menisci's lesions. The ADD and the PDD are related to each other and increase with time. CONCLUSION: There is a permanent anterior subluxation of the injured knee that is related to the amount of anterior displacement that increases with time. Level of Evidence III, Study Types Case-control study. PMID:25246846

Small-animal dark-field radiography for pulmonary emphysema evaluation

NASA Astrophysics Data System (ADS)

Yaroshenko, Andre; Meinel, Felix G.; Hellbach, Katharina; Bech, Martin; Velroyen, Astrid; Müller, Mark; Bamberg, Fabian; Nikolaou, Konstantin; Reiser, Maximilian F.; Yildirim, Ali Ã.-.; Eickelberg, Oliver; Pfeiffer, Franz

2014-03-01

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of morbidity and mortality worldwide and emphysema is one of its main components. The disorder is characterized by irreversible destruction of the alveolar walls and enlargement of distal airspaces. Despite the severe changes in the lung tissue morphology, conventional chest radiographs have only a limited sensitivity for the detection of mild to moderate emphysema. X-ray dark-field is an imaging modality that can significantly increase the visibility of lung tissue on radiographic images. The dark-field signal is generated by coherent, small-angle scattering of x-rays on the air-tissue interfaces in the lung. Therefore, morphological changes in the lung can be clearly visualized on dark-field images. This is demonstrated by a preclinical study with a small-animal emphysema model. To generate a murine model of pulmonary emphysema, a female C57BL/6N mouse was treated with a single orotracheal application of porcine pancreatic elastase (80 U/kg body weight) dissolved in phosphate-buffered saline (PBS). Control mouse received PBS. The mice were imaged using a small-animal dark-field scanner. While conventional x-ray transmission radiography images revealed only subtle indirect signs of the pulmonary disorder, the difference between healthy and emphysematous lungs could be clearly directly visualized on the dark-field images. The dose applied to the animals is compatible with longitudinal studies. The imaging results correlate well with histology. The results of this study reveal the high potential of dark-field radiography for clinical lung imaging.

Multiscale image processing and antiscatter grids in digital radiography.

PubMed

Lo, Winnie Y; Hornof, William J; Zwingenberger, Allison L; Robertson, Ian D

2009-01-01

Scatter radiation is a source of noise and results in decreased signal-to-noise ratio and thus decreased image quality in digital radiography. We determined subjectively whether a digitally processed image made without a grid would be of similar quality to an image made with a grid but without image processing. Additionally the effects of exposure dose and of a using a grid with digital radiography on overall image quality were studied. Thoracic and abdominal radiographs of five dogs of various sizes were made. Four acquisition techniques were included (1) with a grid, standard exposure dose, digital image processing; (2) without a grid, standard exposure dose, digital image processing; (3) without a grid, half the exposure dose, digital image processing; and (4) with a grid, standard exposure dose, no digital image processing (to mimic a film-screen radiograph). Full-size radiographs as well as magnified images of specific anatomic regions were generated. Nine reviewers rated the overall image quality subjectively using a five-point scale. All digitally processed radiographs had higher overall scores than nondigitally processed radiographs regardless of patient size, exposure dose, or use of a grid. The images made at half the exposure dose had a slightly lower quality than those made at full dose, but this was only statistically significant in magnified images. Using a grid with digital image processing led to a slight but statistically significant increase in overall quality when compared with digitally processed images made without a grid but whether this increase in quality is clinically significant is unknown.

Evaluation of the stepwise collimation method for the reduction of the patient dose in full spine radiography

NASA Astrophysics Data System (ADS)

Lee, Boram; Lee, Sunyoung; Yang, Injeong; Yoon, Myeonggeun

2014-05-01

The purpose of this study is to evaluate the dose reduction when using the stepwise collimation method for scoliosis patients undergoing full spine radiography. A Monte Carlo simulation was carried out to acquire dose vs. volume data for organs at risk (OAR) in the human body. While the effective doses in full spine radiography were reduced by 8, 15, 27 and 44% by using four different sizes of the collimation, the doses to the skin were reduced by 31, 44, 55 and 66%, indicating that the reduction of the dose to the skin is higher than that to organs inside the body. Although the reduction rates were low for the gonad, being 9, 14, 18 and 23%, there was more than a 30% reduction in the dose to the heart, suggesting that the dose reduction depends significantly on the location of the OARs in the human body. The reduction rate of the secondary cancer risk based on the excess absolute risk (EAR) varied from 0.6 to 3.4 per 10,000 persons, depending on the size of the collimation. Our results suggest that the stepwise collimation method in full spine radiography can effectively reduce the patient dose and the radiation-induced secondary cancer risk.

Monitoring temporal opacity fluctuations of large structures with muon radiography: a calibration experiment using a water tower

PubMed Central

Jourde, Kevin; Gibert, Dominique; Marteau, Jacques; de Bremond d’Ars, Jean; Gardien, Serge; Girerd, Claude; Ianigro, Jean-Christophe

2016-01-01

Usage of secondary cosmic muons to image the geological structures density distribution significantly developed during the past ten years. Recent applications demonstrate the method interest to monitor magma ascent and volcanic gas movements inside volcanoes. Muon radiography could be used to monitor density variations in aquifers and the critical zone in the near surface. However, the time resolution achievable by muon radiography monitoring remains poorly studied. It is biased by fluctuation sources exterior to the target, and statistically affected by the limited number of particles detected during the experiment. The present study documents these two issues within a simple and well constrained experimental context: a water tower. We use the data to discuss the influence of atmospheric variability that perturbs the signal, and propose correction formulas to extract the muon flux variations related to the water level changes. Statistical developments establish the feasibility domain of muon radiography monitoring as a function of target thickness (i.e. opacity). Objects with a thickness comprised between ≈50 ± 30 m water equivalent correspond to the best time resolution. Thinner objects have a degraded time resolution that strongly depends on the zenith angle, whereas thicker objects (like volcanoes) time resolution does not. PMID:26971718

Evaluation of chest tomosynthesis for the detection of pulmonary nodules: effect of clinical experience and comparison with chest radiography

NASA Astrophysics Data System (ADS)

Zachrisson, Sara; Vikgren, Jenny; Svalkvist, Angelica; Johnsson, Åse A.; Boijsen, Marianne; Flinck, Agneta; Månsson, Lars Gunnar; Kheddache, Susanne; Båth, Magnus

2009-02-01

Chest tomosynthesis refers to the technique of collecting low-dose projections of the chest at different angles and using these projections to reconstruct section images of the chest. In this study, a comparison of chest tomosynthesis and chest radiography in the detection of pulmonary nodules was performed and the effect of clinical experience of chest tomosynthesis was evaluated. Three senior thoracic radiologists, with more than ten years of experience of chest radiology and 6 months of clinical experience of chest tomosynthesis, acted as observers in a jackknife free-response receiver operating characteristics (JAFROC-1) study, performed on 42 patients with and 47 patients without pulmonary nodules examined with both chest tomosynthesis and chest radiography. MDCT was used as reference and the total number of nodules found using MDCT was 131. To investigate the effect of additional clinical experience of chest tomosynthesis, a second reading session of the tomosynthesis images was performed one year after the initial one. The JAFROC-1 figure of merit (FOM) was used as the principal measure of detectability. In comparison with chest radiography, chest tomosynthesis performed significantly better with regard to detectability. The observer-averaged JAFROC-1 FOM was 0.61 for tomosynthesis and 0.40 for radiography, giving a statistically significant difference between the techniques of 0.21 (p<0.0001). The observer-averaged JAFROC-1 FOM of the second reading of the tomosynthesis cases was not significantly higher than that of the first reading, indicating no improvement in detectability due to additional clinical experience of tomosynthesis.

Radiation dose reduction in chest radiography using a flat-panel amorphous silicon detector.

PubMed

Hosch, W P; Fink, C; Radeleff, B; kampschulte a, A; Kauffmann, G W; Hansmann, J

2002-10-01

The aim of this study was to evaluate the image quality and the potential for radiation dose reduction with a digital flat-panel amorphous silicon detector radiography system. Using flat-panel technology, radiographs of an anthropomorphic thorax phantom were taken with a range of technical parameters (125kV, 200mA and 5, 4, 3.2, 2, 1, 0.5, and 0.25mAs) which were equivalent to a radiation dose of 332, 263, 209, 127, 58.7, 29, and 14 microGy, respectively. These images were compared to radiographs obtained by a conventional film-screen radiography system at 125kV, 200mA and 5mAs (equivalent to 252 microGy) which served as reference. Three observers evaluated independently the visibility of simulated rounded lesions and anatomical structures, comparing printed films from the flat-panel amorphous silicon detector and conventional x-ray system films. With flat-panel technology, the visibility of rounded lesions and normal anatomical structures at 5, 4, and 3.2mAs was superior compared to the conventional film-screen radiography system. (P< or =0.0001). At 2mAs, improvement was only marginal (P=0.19). At 1.0, 0.5 and 0.25mAs, the visibility of simulated rounded lesions was worse (P< or =0.004). Comparing fine lung parenchymal structures, the flat-panel amorphous silicon detector showed improvement for all exposure levels down to 2mAs and equality at 1mAs. Compared to a conventional x-ray film system, the flat-panel amorphous silicon detector demonstrated improved image quality and the possibility for a reduction of the radiation dose by 50% without loss in image quality.

X-ray imaging using amorphous selenium: photoinduced discharge (PID) readout for digital general radiography.

PubMed

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.

PEM Water Electrolysis: Preliminary Investigations Using Neutron Radiography

NASA Astrophysics Data System (ADS)

de Beer, Frikkie; van der Merwe, Jan-Hendrik; Bessarabov, Dmitri

The quasi-dynamic water distribution and performance of a proton exchange membrane (PEM) electrolyzer at both a small fuel cell's anode and cathode was observed and quantitatively measured in the in-plane imaging geometry direction(neutron beam parallel to membrane and with channels parallel to the beam) by applying the neutron radiography principle at the neutron imaging facility (NIF) of NIST, Gaithersburg, USA. The test section had 6 parallel channels with an active area of 5 cm2 and in-situ neutron radiography observation entails the liquid water content along the total length of each of the channels. The acquisition was made with a neutron cMOS-camera system with performance of 10 sec per frame to achieve a relatively good pixel dynamic range and at a pixel resolution of 10 x 10 μm2. A relatively high S/N ratio was achieved in the radiographs to observe in quasi real time the water management as well as quantification of water / gas within the channels. The water management has been observed at increased steps (0.2A/cm2) of current densities until 2V potential has been achieved. These observations were made at 2 different water flow rates, at 3 temperatures for each flow rate and repeated for both the vertical and horizontal electrolyzer orientation geometries. It is observed that there is water crossover from the anode through the membrane to the cathode. A first order quantification (neutron scattering correction not included) shows that the physical vertical and horizontal orientation of the fuel cell as well as the temperature of the system up to 80 °C has no significant influence on the percentage water (∼18%) that crossed over into the cathode. Additionally, a higher water content was observed in the Gas Diffusion Layer at the position of the channels with respect to the lands.

An overview of LLNL high-energy short-pulse technology for advanced radiography of laser fusion experiments

NASA Astrophysics Data System (ADS)

Barty, C. P. J.; Key, M.; Britten, J.; Beach, R.; Beer, G.; Brown, C.; Bryan, S.; Caird, J.; Carlson, T.; Crane, J.; Dawson, J.; Erlandson, A. C.; Fittinghoff, D.; Hermann, M.; Hoaglan, C.; Iyer, A.; Jones, L., II; Jovanovic, I.; Komashko, A.; Landen, O.; Liao, Z.; Molander, W.; Mitchell, S.; Moses, E.; Nielsen, N.; Nguyen, H.-H.; Nissen, J.; Payne, S.; Pennington, D.; Risinger, L.; Rushford, M.; Skulina, K.; Spaeth, M.; Stuart, B.; Tietbohl, G.; Wattellier, B.

2004-12-01

The technical challenges and motivations for high-energy, short-pulse generation with NIF and possibly other large-scale Nd : glass lasers are reviewed. High-energy short-pulse generation (multi-kilojoule, picosecond pulses) will be possible via the adaptation of chirped pulse amplification laser techniques on NIF. Development of metre-scale, high-efficiency, high-damage-threshold final optics is a key technical challenge. In addition, deployment of high energy petawatt (HEPW) pulses on NIF is constrained by existing laser infrastructure and requires new, compact compressor designs and short-pulse, fibre-based, seed-laser systems. The key motivations for HEPW pulses on NIF is briefly outlined and includes high-energy, x-ray radiography, proton beam radiography, proton isochoric heating and tests of the fast ignitor concept for inertial confinement fusion.

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

PubMed Central

Silva, Luiz Antonio F.; Barriviera, Mauricio; Januário, Alessandro L.; Bezerra, Ana Cristina B.; Fioravanti, Maria Clorinda S.

2011-01-01

The development of veterinary dentistry has substantially improved the ability to diagnose canine and feline dental abnormalities. Consequently, examinations previously performed only on humans are now available for small animals, thus improving the diagnostic quality. This has increased the need for technical qualification of veterinary professionals and increased technological investments. This study evaluated the use of cone beam computed tomography and intraoral radiography as complementary exams for diagnosing dental abnormalities in dogs and cats. Cone beam computed tomography was provided faster image acquisition with high image quality, was associated with low ionizing radiation levels, enabled image editing, and reduced the exam duration. Our results showed that radiography was an effective method for dental radiographic examination with low cost and fast execution times, and can be performed during surgical procedures. PMID:22122905

Single-image hard-copy display of the spine utilizing digital radiography

NASA Astrophysics Data System (ADS)

Artz, Dorothy S.; Janchar, Timothy; Milzman, David; Freedman, Matthew T.; Mun, Seong K.

1997-04-01

Regions of the entire spine contain a wide latitude of tissue densities within the imaged field of view presenting a problem for adequate radiological evaluation. With screen/film technology, the optimal technique for one area of the radiograph is sub-optimal for another area. Computed radiography (CR) with its inherent wide dynamic range, has been shown to be better than screen/film for lateral cervical spine imaging, but limitations are still present with standard image processing. By utilizing a dynamic range control (DRC) algorithm based on unsharp masking and signal transformation prior to gradation and frequency processing within the CR system, more vertebral bodies can be seen on a single hard copy display of the lateral cervical, thoracic, and thoracolumbar examinations. Examinations of the trauma cross-table lateral cervical spine, lateral thoracic spine, and lateral thoracolumbar spine were collected on live patient using photostimulable storage phosphor plates, the Fuji FCR 9000 reader, and the Fuji AC-3 computed radiography reader. Two images were produced from a single exposure; one with standard image processing and the second image with the standard process and the additional DRC algorithm. Both sets were printed from a Fuji LP 414 laser printer. Two different DRC algorithms were applied depending on which portion of the spine was not well visualized. One algorithm increased optical density and the second algorithm decreased optical density. The resultant image pairs were then reviewed by a panel of radiologists. Images produced with the additional DRC algorithm demonstrated improved visualization of previously 'under exposed' and 'over exposed' regions within the same image. Where lung field had previously obscured bony detail of the lateral thoracolumbar spine due to 'over exposure,' the image with the DRC applied to decrease the optical density allowed for easy visualization of the entire area of interest. For areas of the lateral cervical spine

Energy-resolved fast neutron resonance radiography at CSNS

NASA Astrophysics Data System (ADS)

Tan, Zhixin; Tang, Jingyu; Jing, Hantao; Fan, Ruirui; Li, Qiang; Ning, Changjun; Bao, Jie; Ruan, Xichao; Luan, Guangyuan; Feng, Changqin; Zhang, Xianpeng

2018-05-01

The white neutron beamline at the China Spallation Neutron Source will be used mainly for nuclear data measurements. It will be characterized by high flux and broad energy spectra. To exploit the beamline as a neutron imaging source, we propose a liquid scintillator fiber array for fast neutron resonance radiography. The fiber detector unit has a small exposed area, which will limit the event counts and separate the events in time, thus satisfying the requirements for single-event time-of-flight (SEToF) measurement. The current study addresses the physical design criteria for ToF measurement, including flux estimation and detector response. Future development and potential application of the technology are also discussed.

Proton Radiography With Timepix Based Time Projection Chambers.

PubMed

Biegun, Aleksandra K; Visser, Jan; Klaver, Tom; Ghazanfari, Nafiseh; van Goethem, Marc-Jan; Koffeman, Els; van Beuzekom, Martin; Brandenburg, Sytze

2016-04-01

The development of a proton radiography system to improve the imaging of patients in proton beam therapy is described. The system comprises gridpix based time projection chambers, which are based on the Timepix chip designed by the Medipix collaboration, for tracking the protons. This type of detector was chosen to have minimal impact on the actual determination of the proton tracks by the tracking detectors. To determine the residual energy of the protons, a BaF 2 crystal with a photomultiplier tube is used. We present data taken in a feasibility experiment with phantoms that represent tissue equivalent materials found in the human body. The obtained experimental results show a good agreement with the performed simulations.

Identification of Nasal Bone Fractures on Conventional Radiography and Facial CT: Comparison of the Diagnostic Accuracy in Different Imaging Modalities and Analysis of Interobserver Reliability

PubMed Central

Baek, Hye Jin; Kim, Dong Wook; Ryu, Ji Hwa; Lee, Yoo Jin

2013-01-01

Background There has been no study to compare the diagnostic accuracy of an experienced radiologist with a trainee in nasal bone fracture. Objectives To compare the diagnostic accuracy between conventional radiography and computed tomography (CT) for the identification of nasal bone fractures and to evaluate the interobserver reliability between a staff radiologist and a trainee. Patients and Methods A total of 108 patients who underwent conventional radiography and CT after acute nasal trauma were included in this retrospective study. Two readers, a staff radiologist and a second-year resident, independently assessed the results of the imaging studies. Results Of the 108 patients, the presence of a nasal bone fracture was confirmed in 88 (81.5%) patients. The number of non-depressed fractures was higher than the number of depressed fractures. In nine (10.2%) patients, nasal bone fractures were only identified on conventional radiography, including three depressed and six non-depressed fractures. CT was more accurate as compared to conventional radiography for the identification of nasal bone fractures as determined by both readers (P <0.05), all diagnostic indices of an experienced radiologist were similar to or higher than those of a trainee, and κ statistics showed moderate agreement between the two diagnostic tools for both readers. There was no statistical difference in the assessment of interobserver reliability for both imaging modalities in the identification of nasal bone fractures. Conclusion For the identification of nasal bone fractures, CT was significantly superior to conventional radiography. Although a staff radiologist showed better values in the identification of nasal bone fracture and differentiation between depressed and non-depressed fractures than a trainee, there was no statistically significant difference in the interpretation of conventional radiography and CT between a radiologist and a trainee. PMID:24348599

Identification of Nasal Bone Fractures on Conventional Radiography and Facial CT: Comparison of the Diagnostic Accuracy in Different Imaging Modalities and Analysis of Interobserver Reliability.

PubMed

Baek, Hye Jin; Kim, Dong Wook; Ryu, Ji Hwa; Lee, Yoo Jin

2013-09-01

There has been no study to compare the diagnostic accuracy of an experienced radiologist with a trainee in nasal bone fracture. To compare the diagnostic accuracy between conventional radiography and computed tomography (CT) for the identification of nasal bone fractures and to evaluate the interobserver reliability between a staff radiologist and a trainee. A total of 108 patients who underwent conventional radiography and CT after acute nasal trauma were included in this retrospective study. Two readers, a staff radiologist and a second-year resident, independently assessed the results of the imaging studies. Of the 108 patients, the presence of a nasal bone fracture was confirmed in 88 (81.5%) patients. The number of non-depressed fractures was higher than the number of depressed fractures. In nine (10.2%) patients, nasal bone fractures were only identified on conventional radiography, including three depressed and six non-depressed fractures. CT was more accurate as compared to conventional radiography for the identification of nasal bone fractures as determined by both readers (P <0.05), all diagnostic indices of an experienced radiologist were similar to or higher than those of a trainee, and κ statistics showed moderate agreement between the two diagnostic tools for both readers. There was no statistical difference in the assessment of interobserver reliability for both imaging modalities in the identification of nasal bone fractures. For the identification of nasal bone fractures, CT was significantly superior to conventional radiography. Although a staff radiologist showed better values in the identification of nasal bone fracture and differentiation between depressed and non-depressed fractures than a trainee, there was no statistically significant difference in the interpretation of conventional radiography and CT between a radiologist and a trainee.

Managers' experience of success criteria and barriers to implementing mobile radiography services in nursing homes in Norway: a qualitative study.

PubMed

Kjelle, Elin; Lysdahl, Kristin Bakke; Olerud, Hilde Merete; Myklebust, Aud Mette

2018-04-25

In order to meet the future challenges posed by ageing populations, new technology, telemedicine and a more personalized healthcare system are needed. Earlier research has shown mobile radiography services to be highly beneficial for nursing home residents in addition to being cost-effective. Despite the benefits, mobile radiography services are uncommon in Europe and Norway. The purpose of this study was to explore success criteria and barriers in the process of implementing mobile radiography services, from the point of view of the hospital and municipal managers. Eleven semi-structured interviews were conducted with managers from five hospitals and six municipalities in Norway where mobile radiography services had been implemented. Core issues in the interview guide were barriers and facilitators in the different phases of implementation. The framework method for thematic analysis was used for analysing the data inductively in a research team. Five main categories were developed through the success criteria and barriers experienced by the participants: national health policy, regional and municipal policy and conditions, inter-organizational implementation projects, experienced outcome, and professional skills and personal characteristics. The categories were allocated into three higher-order classifications: macro, meso and micro levels. The main barriers experienced by the managers were financial, procedural and structural. In particular, the reimbursement system, lack of management across healthcare levels and the lack of compatible information systems acted as barriers. The main facilitators were external funding, enthusiastic individuals in the organizations and good collaboration between hospitals and municipalities. The managers experienced financial, structural and procedural barriers. The main success criteria in the process were external funding, and the support and engagement from the individuals in the organizations. This commitment was mainly

Awareness of radiation protection and dose levels of imaging procedures among medical students, radiography students, and radiology residents at an academic hospital: Results of a comprehensive survey.

PubMed

Faggioni, Lorenzo; Paolicchi, Fabio; Bastiani, Luca; Guido, Davide; Caramella, Davide

2017-01-01

To evaluate the awareness of radiation protection issues and the knowledge of dose levels of imaging procedures among medical students, radiology residents, and radiography students at an academic hospital. A total of 159 young doctors and students (including 60 radiology residents, 56 medical students, and 43 radiography students) were issued a questionnaire consisting of 16 multiple choice questions divided into three separated sections (i.e., demographic data, awareness about radiation protection issues, and knowledge about radiation dose levels of common radiological examinations). Medical students claimed to have at least a good knowledge of radiation protection issues more frequently than radiology residents and radiography students (94.4% vs 55% and 35.7%, respectively; P<0.05), with no cases of perceived excellent knowledge among radiography students. However, the actual knowledge of essential radiation protection topics such as regulations, patient and tissue susceptibility to radiation damage, professional radiation risk and dose optimisation, as well as of radiation doses delivered by common radiological procedures was significantly worse among medical students than radiology residents and radiography students (P<0.05). Those latter significantly outperformed radiology residents as to knowledge of radiation protection issues (P<0.01). Overall, less than 50% of survey respondents correctly answered all questions of the survey. Radiology residents, radiography students and medical students have a limited awareness about radiation protection, with a specific gap of knowledge concerning real radiation doses of daily radiological examinations. Both undergraduate and postgraduate teaching needs to be effectively implemented with radiation safety courses. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Trace fossils revealed through x-radiography in facies analysis of Smackover Formation, southwest Alabama

DOE Office of Scientific and Technical Information (OSTI.GOV)

Esposito, R.A.; King, D.T. Jr.

The use of x-radiography has been applied to slabbed cores of Jurassic Smackover limestones from southwestern Alabama to enhance the complete petrologic description of the rocks. Through x-radiography, trace fossils have been revealed in what would otherwise appear to be homogeneous rock. In these biogenic structures, organic material, partly fecal in origin, is concentrated as infill packing in actively filled burrows. A microreducing environment within the burrow results in the mineralization by finely disseminated FeS/sub 2/. The density difference between FeS/sub 2/, which has a high absorption coefficient, and the surrounding calcium carbonate highlights the burrows in the x-radiographs. Thismore » characteristic burrow mineralization is shown well in the Smackover where a Zoophycus-Thalassinoides trace-fossil assemblage has been identified. Zoophycus, a feeding structure, is characterized by concave-upward traces with whorled peaks, and is best seen in slabs cut perpendicular to bedding. Thalassinoides is a dwelling structure characterized by a boxwork burrow system and is best seen in cores cut parallel to bedding. This assemblage is restricted to facies that is laterally persistent throughout the Smackover in most of Escambia County, Alabama. This trace-fossil assemblage is found in an oolitic pelletal packstone. This unit is overlain by an oolitic grainstone and is stratigraphically above a sparsely fossiliferous, laminated wackestone and packstone. Trace fossils in this horizon are abundant, but the traces are not found in stratigraphically adjacent lithofacies. Detecting these otherwise unseen trace fossils by x-radiography assisted the paleoenvironmental interpretation of this depositional facies as a low-energy subwave-base carbonate-shelf deposit.« less

WE-EF-303-08: Proton Radiography Using Pencil Beam Scanning and Novel Micromegas Detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dolney, D; Lustig, R; Teo, B

Purpose: While the energy of therapeutic proton beams can be adjusted to penetrate to any given depth in water, range uncertainties arise in patients due in part to imprecise knowledge of the stopping power of protons in human tissues. Proton radiography is one approach to reduce the beam range uncertainty, thereby allowing for a reduction in treatment margins and dose escalation. Methods: The authors have adapted a novel detector technology based on Micromesh Gaseous Structure (“Micromegas”) for proton therapy beams and have demonstrated fine spatial and time resolution of magnetically scanned proton pencil beams, as well as wide dynamic rangemore » for dosimetry. In this work, proton radiographs were obtained using Micromegas 2D planes positioned downstream of solid water assemblies. The position-sensitive monitor chambers in the IBA proton delivery nozzle provide the beam entrance position. Results: Radiography with Micromegas detectors and actively scanned beams provide spatial resolution of up to 300 µm and water-equivalent thickness (WET) resolution as good as 0.02% (60 µm out of 31 cm total thickness), with the dose delivered to the patient kept below 2 cGy. The spatial resolution as a function of sample rate and number of delivered protons is found to be near the theoretical Cramer-Rao lower bound. Using the CR bound, we argue that the imaging dose could be further lowered to 1 mGy, while still achieving sub-mm spatial resolution, by relatively simple instrumentation upgrades and beam delivery modifications. Conclusion: For proton radiography, high spatial and WET resolution can be achieved, with minimal additional dose to patient, by using magnetically scanned proton pencil beams and Micromegas detectors.« less

Radiography Faculty Engaged in Online Education: Perceptions of Effectiveness, Satisfaction, and Technological Self-efficacy.

PubMed

Cherry, Shirley J; Flora, Bethany H

2017-01-01

To assess radiography faculty perceptions of the effectiveness of online courses. An original survey instrument was created by selecting items from 3 instruments used in prior research and adding unique questions designed to elicit demographic data from faculty. The sample included a national dataset of radiography faculty members employed in Joint Review Committee on Education in Radiologic Technology-accredited programs in the United States. Findings showed that faculty perceptions of online course effectiveness are not affected significantly by faculty position, type of institution, faculty age, or years of teaching experience. Positive perceptions of the effectiveness of online courses moderately increased with years of teaching online courses, number of online courses taught in the past 5 years, and perceived competence with the use of technology. Faculty satisfaction with interaction in online courses moderately increased as the years of teaching online courses increased. However, the number of years of teaching online courses was not related to faculty satisfaction with teaching online courses or faculty satisfaction with institutional support. Online technology acceptance had a moderately positive relationship with perceived ease of use and a strong positive relationship with perceived usefulness of online technology. In addition, the use of technology-enhanced learning methods had a strong positive relationship with technological self-efficacy. Radiography faculty perceptions of the effectiveness of online courses improved with experience in teaching online courses and competence with use of technology. Perceived ease of use and perceived usefulness of online technology were related directly to online technology acceptance. Furthermore, faculty members with technological self-efficacy were more likely to use technology-enhanced learning methods in the online environment.

A novel approach to determine post mortem interval using neutron radiography.

PubMed

Bilheux, Hassina Z; Cekanova, Maria; Vass, Arpad A; Nichols, Trent L; Bilheux, Jean C; Donnell, Robert L; Finochiarro, Vincenzo

2015-06-01

One of the most difficult challenges in forensic research is to objectively determine the post-mortem interval (PMI). The accuracy of PMI is critical for determining the timeline of events surrounding a death. Most PMI techniques rely on gross morphological changes of cadavers that are highly sensitive to taphonomic factors. Recent studies have demonstrated that even exhumed individuals exposed to the same environmental conditions with similar PMIs can present different stages of decomposition. After death, tissue undergoes sequential changes consisting of organic and inorganic phase variations, as well as a gradual reduction of tissue water content. Hydrogen (H) is the primary contributor to neutron radiography (NR) contrast in biological specimens because (1) it is the most abundant element in biological tissues and (2) its nucleus scatters thermal and cold neutrons more strongly than any other atomic nucleus. These contrast differences can be advantageous in a forensic context to determine small changes in hydrogen concentrations. Neutron radiography of decaying canine tissues was performed to evaluate the PMI by measuring the changes in H content. In this study, dog cadavers were used as a model for human cadavers. Canine tissues and cadavers were exposed to controlled (laboratory settings, at the University of Tennessee, College of Veterinary Medicine) and uncontrolled (University of Tennessee Anthropology Research Facility) environmental conditions, respectively. Neutron radiographs were supplemented with photographs and histology data to assess the decompositional stages of cadavers. Results demonstrated that the increase in neutron transmission likely corresponded to a decrease in hydrogen content in the tissue, which was correlated with the decay time of the tissue. Tissues depleted in hydrogen were brighter in the neutron transmission radiographs of skeletal muscles, lung, and bone, under controlled conditions. Over a period of 10 days, changes in neutron

Tolerance of image enhancement brightness and contrast in lateral cephalometric digital radiography for Steiner analysis

NASA Astrophysics Data System (ADS)

Rianti, R. A.; Priaminiarti, M.; Syahraini, S. I.

2017-08-01

Image enhancement brightness and contrast can be adjusted on lateral cephalometric digital radiographs to improve image quality and anatomic landmarks for measurement by Steiner analysis. To determine the limit value for adjustments of image enhancement brightness and contrast in lateral cephalometric digital radiography for Steiner analysis. Image enhancement brightness and contrast were adjusted on 100 lateral cephalometric radiography in 10-point increments (-30, -20, -10, 0, +10, +20, +30). Steiner analysis measurements were then performed by two observers. Reliabilities were tested by the Interclass Correlation Coefficient (ICC) and significance tested by ANOVA or the Kruskal Wallis test. No significant differences were detected in lateral cephalometric analysis measurements following adjustment of the image enhancement brightness and contrast. The limit value of adjustments of the image enhancement brightness and contrast associated with incremental 10-point changes (-30, -20, -10, 0, +10, +20, +30) does not affect the results of Steiner analysis.

Temporally resolved proton radiography of rapidly varying electric and magnetic fields in laser-driven capacitor coil targets

NASA Astrophysics Data System (ADS)

Morace, A.; Santos, J. J.; Bailly-Grandvaux, M.; Ehret, M.; Alpinaniz, J.; Brabetz, C.; Schaumann, G.; Volpe, L.

2017-02-01

Understanding the dynamics of rapidly varying electromagnetic fields in intense short pulse laser plasma interactions is of key importance to understand the mechanisms at the basis of a wide variety of physical processes, from high energy density physics and fusion science to the development of ultrafast laser plasma devices to control laser-generated particle beams. Target normal sheath accelerated (TNSA) proton radiography represents an ideal tool to diagnose ultrafast electromagnetic phenomena, providing 2D spatially and temporally resolved radiographs with temporal resolution varying from 2-3 ps to few tens of ps. In this work we introduce the proton radiography technique and its application to diagnose the spatial and temporal evolution of electromagnetic fields in laser-driven capacitor coil targets.

Differences in the morphology of distal border synovial invaginations of the distal sesamoid bone in the horse as evaluated by computed tomography compared with radiography.

PubMed

Claerhoudt, S; Bergman, H J; Van Der Veen, H; Duchateau, L; Raes, E V; Saunders, J H

2012-11-01

Distal border synovial invaginations of the distal sesamoid bone are radiographically assessed during the selection process of horses admitted as breeding stallions or in purchase examinations. Nowadays, many moderately or some deeply penetrating proximally enlarged synovial invaginations are considered as moderate or severe radiographic findings. To measure the difference between and agreement of the morphology of distal border synovial invaginations on radiography vs. computed tomography (CT). It was hypothesised that the morphology of distal border synovial invaginations would be better evaluable on CT compared with radiography. Computed tomography scans and 3 dorsoproximal-palmarodistal oblique (DPr-PaDiO) radiographs were obtained on 50 cadaver forefeet from 25 Warmblood horses. Computed tomography was assumed to be the gold standard. The number, shape and depth of penetration of distal border synovial invaginations into the distal sesamoid bone were evaluated with both methods, and the comparison of their measurements was statistically described. A statistically significant mean difference for number of distal synovial invaginations between CT and all 3 DPr-PaDiO projections was found and was approximately equal to 2, meaning that CT permits visualisation of an average of 2 more invaginations than radiography. In none of the cases did radiography have a higher number observed than CT. A large variation in the difference of measurements for depth of penetration against their mean difference between CT and the 3 radiographic projections was seen. Radiography underestimated the depth of invaginations, and more so when these were deeper. There was no statistically significant mean difference found between the techniques for depth. A moderate to good agreement between measurements on CT and the three DPr-PaDiO projections for shape was seen, in which the D55°Pr-PaDiO projection showed the best agreement. A high specificity (90-99%) and low sensitivity (65%) for

Evaluation of the Radiography Program at Caldwell Community College and Technical Institute--Summer, 1982.

ERIC Educational Resources Information Center

Pipes, V. David

As part of a periodic evaluation of the occupational programs at Caldwell Community College and Technical Institute (CCC&TI), a study of the radiography program was conducted to collect information to facilitate planning, aid in program improvement, and meet accountability demands. The specific objectives of the program evaluation were to…

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

PubMed

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

2014-05-07

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

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

NASA Astrophysics Data System (ADS)

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

2014-05-01

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

Towards a muon radiography of the Puy de Dôme

NASA Astrophysics Data System (ADS)

Cârloganu, C.; Niess, V.; Béné, S.; Busato, E.; Dupieux, P.; Fehr, F.; Gay, P.; Miallier, D.; Vulpescu, B.; Boivin, P.; Combaret, C.; Labazuy, P.; Laktineh, I.; Lénat, J.-F.; Mirabito, L.; Portal, A.

2012-09-01

High energy (above 100 GeV) atmospheric muons are a natural probe for geophysical studies. They can travel through kilometres of rock allowing for a radiography of the density distribution within large structures, like mountains or volcanoes. A collaboration between volcanologists, astroparticle and particle physicists, TOMUVOL, was formed in 2009 to study tomographic muon imaging of volcanoes with high resolution, large scale tracking detectors. We report on two campaigns of measurements at the flank of the Puy de Dôme using Glass Resistive Plate Chambers (GRPCs) developed for Particle Physics, within the CALICE collaboration.

A Comparison of Angular Values of the Pelvic Limb with Normal and Medial Patellar Luxation Stifles in Chihuahua Dogs Using Radiography and Computed Tomography.

PubMed

Phetkaew, Thitaporn; Kalpravidh, Marissak; Penchome, Rampaipat; Wangdee, Chalika

2018-02-01

 This article aimed to determine and compare the angular values of the pelvic limb in normal and medial patellar luxation (MPL) stifles in Chihuahuas using radiography and computed tomographic (CT) scan, to identify the relationship between pelvic limb angles and severity of MPL. In addition, radiographic and CT images were compared to determine the more suitable method of limb deformity assessment.  Sixty hindlimbs of Chihuahuas were divided into normal and grade 1, 2, 3 and 4 MPL groups. The pelvic limb angles in frontal and sagittal planes were evaluated on radiography and CT scan. Femoral and tibial torsion angles (FTA and TTA) were evaluated only by CT scan. All angles were compared among normal and MPL stifles and between radiography and CT scan.  Based on the CT scan, the mechanical lateral distal femoral angle (mLDFA), anatomical caudal proximal femoral angle (aCdPFA), and TTA were related to the severity of MPL. The mLDFA and TTA were significantly increased ( p  < 0.05) in grade 4 MPL, while the aCdPFA was significantly decreased in grade 2, 3 and 4 MPL groups. There were significant differences of many angles between radiography and CT scan.  The angles related to MPL in Chihuahuas are aLDFA, mLDFA, aCdPFA and TTA. Radiography had some limitations for evaluating pelvic limb angles. The caudocranial radiograph is recommended for the assessment of the distal femoral angles, while the craniocaudal radiograph is for the tibial angles. Schattauer GmbH Stuttgart.

Accuracy and precision of computer-assisted analysis of bone density via conventional and digital radiography in relation to dual-energy x-ray absorptiometry.

PubMed

Vaccaro, Calogero; Busetto, Roberto; Bernardini, Daniele; Anselmi, Carlo; Zotti, Alessandro

2012-03-01

To evaluate the precision and accuracy of assessing bone mineral density (BMD) by use of mean gray value (MGV) on digitalized and digital images of conventional and digital radiographs, respectively, of ex vivo bovine and equine bone specimens in relation to the gold-standard technique of dual-energy x-ray absorptiometry (DEXA). Left and right metatarsal bones from 11 beef cattle and right femurs from 2 horses. Bovine specimens were imaged by use of conventional radiography, whereas equine specimens were imaged by use of computed radiography (digital radiography). Each specimen was subsequently scanned by use of the same DEXA equipment. The BMD values resulting from each DEXA scan were paired with the MGVs obtained by use of software on the corresponding digitalized or digital radiographic image. The MGV analysis of digitalized and digital x-ray images was a precise (coefficient of variation, 0.1 and 0.09, respectively) and highly accurate method for assessing BMD, compared with DEXA (correlation coefficient, 0.910 and 0.937 for conventional and digital radiography, respectively). The high correlation between MGV and BMD indicated that MGV analysis may be a reliable alternative to DEXA in assessing radiographic bone density. This may provide a new, inexpensive, and readily available estimate of BMD.

The learning curve in short-stem THA: influence of the surgeon's experience on intraoperative adjustments due to intraoperative radiography.

PubMed

Loweg, Lennard; Kutzner, Karl Philipp; Trost, Matthias; Hechtner, Marlene; Drees, Philipp; Pfeil, Joachim; Schneider, Michael

2018-02-01

Short-stem THA has become increasingly popular over the last decade. However, implantation technique differs from conventional THA and thus possibly involves a distinct learning curve. The purpose of this study was to evaluate the value of intraoperative radiography and the influence of the surgeon's experience on intraoperative adjustments in short-stem THA. A total of 287 consecutive short-stem THAs, operated by a total of 24 senior consultants, consultants and residents in training, were prospectively included. Intraoperative radiography was performed after trial reduction. Preoperative planning and intraoperative outcome with regard to positioning, sizing of components as well as resulting offset and leg length were compared. Frequency, reason and type of intraoperative adjustments were documented in relation to the surgeon's experience. Operation time was assessed. One hundred and fifty-six (54.4%) procedures were carried out by one of three senior consultants, and a total of nine consultants and 12 residents in training performed 105 (36.6%) and 26 (9.0%) operations, respectively. In 121 cases (42.2%), intraoperative adjustments were made following intraoperative radiography. Intraoperative adjustments of one or more components were made by senior consultants in 51 cases (32.7%), by consultants in 53 cases (50.5%) and by residents in 17 cases (65.4%), respectively. The most common cause was undersizing of the stem. Operation time varied markedly between groups of surgeons. Short-stem THA involves a learning curve. Intraoperative radiography is decisive for prevention of malpositioning and undersizing of components, as well as loss of offset and leg length discrepancies. Hence, it should be considered mandatory, especially for less experienced surgeons.

75 FR 27368 - Aerotest Operations, Inc., Aerotest Radiography and Research Reactor; Notice of Consideration of...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-14

...., Aerotest Radiography and Research Reactor; Notice of Consideration of Approval of Transfer and Conforming Amendment, Opportunity for a Hearing, and Order Imposing Procedures for Access to Sensitive Unclassified Non... Manager, Research and Test Reactors Licensing Branch, Division of Policy and Rulemaking, Office of Nuclear...

Application of Deconvolution Algorithm of Point Spread Function in Improving Image Quality: An Observer Preference Study on Chest Radiography.

PubMed

Chae, Kum Ju; Goo, Jin Mo; Ahn, Su Yeon; Yoo, Jin Young; Yoon, Soon Ho

2018-01-01

To evaluate the preference of observers for image quality of chest radiography using the deconvolution algorithm of point spread function (PSF) (TRUVIEW ART algorithm, DRTECH Corp.) compared with that of original chest radiography for visualization of anatomic regions of the chest. Prospectively enrolled 50 pairs of posteroanterior chest radiographs collected with standard protocol and with additional TRUVIEW ART algorithm were compared by four chest radiologists. This algorithm corrects scattered signals generated by a scintillator. Readers independently evaluated the visibility of 10 anatomical regions and overall image quality with a 5-point scale of preference. The significance of the differences in reader's preference was tested with a Wilcoxon's signed rank test. All four readers preferred the images applied with the algorithm to those without algorithm for all 10 anatomical regions (mean, 3.6; range, 3.2-4.0; p < 0.001) and for the overall image quality (mean, 3.8; range, 3.3-4.0; p < 0.001). The most preferred anatomical regions were the azygoesophageal recess, thoracic spine, and unobscured lung. The visibility of chest anatomical structures applied with the deconvolution algorithm of PSF was superior to the original chest radiography.

Characterization of Makrofol ® DE 1-1 for alpha particle radiography

NASA Astrophysics Data System (ADS)

El Ghazaly, M.; Aydarous, Abdulkadir; Al-Thomali, Talal A.

2017-09-01

Makrofol ® DE 1-1 (bisphenol-A polycarbonate) was investigated for alpha particle radiography. The edge spread function (ESF) was measured by razor-blade's edge. Makrofol ® DE 1-1 detectors were irradiated with perpendicular incident alpha particles of energy 2.5, 4 and 5.4 MeV, thereafter they were etched in 75% 6N KOH+25% C2H5OH at a temperature of 50 °C for different durations. The etched Makrofol®DE 1-1 detectors were imaged with an optical microscope equipped with a CCD camera. The results revealed that the green channel of the original RGB image provides the highest contrast comparing with red and blue channel by a factor of 27.6% of the original RGB image. The image contrast of alpha particle-irradiated Makrofol®DE 1-1 detector was found to be inversely related to the etching time since the alpha particle tracks proceed from a conical phase to spherical phase. The spatial resolution of alpha particle-irradiated Makrofol®DE 1-1 detector, in terms of line spread function, was found to deteriorate as the etching time increases for all examined alpha particle energies. The results revealed the potential capability of Makrofol®DE 1-1 detector as an efficient detector for alpha particle radiography such as autoradiography.

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

NASA Astrophysics Data System (ADS)

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.

Lonizing radiation regulations and the dental practitioner: 3. Quality assurance in dental radiography.

PubMed

Rout, John; Brown, Jackie

2012-06-01

This is the last in a series of three articles on X-ray dose reduction and covers aspects of quality assurance. The first outlined radiation physics and protection and the second the legislation relating to radiation safety. Quality assurance is an essential part of dental radiography and is required to produce images of a consistently high standard, necessary for accurate diagnosis.

Composite structure of helicopter rotor blades studied by neutron- and X-ray radiography

NASA Astrophysics Data System (ADS)

Balaskó, M.; Veres, I.; Molnár, Gy.; Balaskó, Zs.; Sváb, E.

2004-07-01

In order to inspect the possible defects in the composite structure of helicopter rotor blades combined neutron- and X-ray radiography investigations were performed at the Budapest Research Reactor. Imperfections in the honeycomb structure, resin rich or starved areas at the core-honeycomb surfaces, inhomogeneities at the adhesive filling and water percolation at the sealing interfaces of the honeycomb sections were discovered.

An unexpected cause of vaginal bleeding: the role of pelvic radiography.

PubMed

Kyrgios, Ioannis; Emmanouilidou, Eleftheria; Theodoridis, Theodoros; Galli-Tsinopoulou, Assimina

2014-02-14

Vaginal bleeding and/or discharge in young girls may result from infection, urological problems, endocrine causes, bleeding disorders, dermatological conditions, trauma, sexual abuse, masses or foreign bodies. We report a case of excessive vaginal bleeding caused by a foreign body in a prepubertal girl with emphasis on the diagnostic challenges and pitfalls regarding imaging techniques. In our patient, although invasive and expensive investigations had been initially made, the foreign body was last detected only when a plain pelvic radiography was performed.

Skin entrance dose with and without lead apron in digital panoramic radiography for selected sensitive body regions.

PubMed

Schulze, Ralf Kurt Willy; Cremers, Catrin; Karle, Heiko; de Las Heras Gala, Hugo

2017-05-01

The aim of this study was to compare the dose at skin level at five significant anatomical regions for panoramic radiography devices with and without lead apron by means of a highly sensitive dosimeter. A female RANDO-phantom was exposed in five different digital panoramic radiography systems, and the dose at skin level was assessed tenfold for each measurement region by means of a highly sensitive solid-state-dosimeter. The five measurement regions selected were the thyroid, both female breasts, the gonads, and a central region in the back of the phantom. For each panoramic machine, the measurements were performed in two modes: with and without a commercial lead apron specifically designed for panoramic radiography. Reproducibility of the measurements was expressed by absolute differences and the coefficient of variation. Values between shielded and unshielded doses were pooled for each region and compared by means of the paired Wilcoxon tests (p ≤ 0.05). Reproducibility as represented by the mean CV was 22 ± 52 % (median 2.3 %) with larger variations for small dose values. Doses at skin level ranged between 0.00 μGy at the gonads and 85.39 μGy at the unshielded thyroid (mean ± SD 15 ± 24 μGy). Except for the gonads, the dose in all the other regions was significantly lower (p < 0.001) when a lead apron was applied. Unshielded doses were between 1.02-fold (thyroid) and 112-fold (at the right breast) higher than those with lead apron shielding (mean: 14-fold ± 18-fold). Although the doses were entirely very low, we observed a significant increase in dose in the radiation-sensitive female breast region when no lead apron was used. Future discussions on shielding requirements for panoramic radiography should focus on these differences in the light of the linear non-threshold (LNT) theory which is generally adopted in medical imaging.

Water Calibration Measurements for Neutron Radiography: Application to Water Content Quantification in Porous Media

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, Misun; Bilheux, Hassina Z; Voisin, Sophie

2013-04-01

Using neutron radiography, the measurement of water thickness was performed using aluminum (Al) water calibration cells at the High Flux Isotope Reactor (HFIR) Cold-Guide (CG) 1D neutron imaging facility at Oak Ridge National Laboratory, Oak Ridge, TN, USA. Calibration of water thickness is an important step to accurately measure water contents in samples of interest. Neutron attenuation by water does not vary linearly with thickness mainly due to beam hardening and scattering effects. Transmission measurements for known water thicknesses in water calibration cells allow proper correction of the underestimation of water content due to these effects. As anticipated, strong scatteringmore » effects were observed for water thicknesses greater than 2 mm when the water calibration cells were positioned close to the face of the detector / scintillator (0 and 2.4 cm away, respectively). The water calibration cells were also positioned 24 cm away from the detector face. These measurements resulted in less scattering and this position (designated as the sample position) was used for the subsequent experimental determination of the neutron attenuation coefficient for water. Neutron radiographic images of moist Flint sand in rectangular and cylindrical containers acquired at the sample position were used to demonstrate the applicability of the water calibration. Cumulative changes in the water volumes within the sand columns during monotonic drainage determined by neutron radiography were compared with those recorded by direct reading from a burette connected to a hanging water column. In general, the neutron radiography data showed very good agreement with those obtained volumetrically using the hanging water-column method. These results allow extension of the calibration equation to the quantification of unknown water contents within other samples of porous media.« less

Genotoxic effects of X-rays on keratinized mucosa cells during panoramic dental radiography.

PubMed

Cerqueira, E M M; Meireles, J R C; Lopes, M A; Junqueira, V C; Gomes-Filho, I S; Trindade, S; Machado-Santelli, G M

2008-10-01

The aim of this study was to evaluate the genotoxic effects of X-rays on epithelial gingival cells during panoramic dental radiography using a differentiated protocol for the micronucleus test. 40 healthy individuals who underwent this procedure for diagnostic purposes on request from their dentists agreed to participate in this study. All of them answered a questionnaire before the examination. Epithelial gingival cells were obtained from the keratinized mucosa of the upper dental arcade by gentle scraping with a cervical brush immediately before exposure and 10 days later. Cytological preparations were stained according to the Feulgen-Rossenbeck reaction, counterstained with fast green 1% for 1 min and analysed under a light microscope. Micronuclei, nuclear projections (broken eggs) and degenerative nuclear alterations (pyknosis, karyolysis, karyorrhexis and condensed chromatin) were scored. The frequency of micronuclei was significantly higher after exposure (P < 0.05), as were the frequencies of nuclear alterations indicative of apoptosis (P < 0.001). These results indicate that X-ray radiation emitted during panoramic dental radiography induces a genotoxic effect on epithelial gingival cells that increases the frequency of chromosomal damage and nuclear alterations indicative of apoptosis.

A clinical study comparing digital radiography and near-infrared transillumination in caries detection.

PubMed

Berg, Stephen C; Stahl, Jonathan Miles; Lien, Wen; Slack, Casey M; Vandewalle, Kraig S

2018-01-01

The purpose of this study was to compare the effectiveness of detecting proximal carious lesions utilizing a new near-infrared transillumination (NIRTI) system (CariVu, Dexis) to traditional digital bitewing radiography (BWXR). Thirty patients received four posterior BWXRs and all premolars and molars were individually imaged with the NIRTI device. Sixty-seven proximal carious lesions were classified based on their depth into enamel or dentin for both BWXR and NIRTI images. The caries depth classification between the two systems were strongly correlated (r s  = 0.66; Spearman range: 0.60-0.79 = strong) and significant (P < .001) with a median score of 3 for NIRTI and 2 for BWXR. The new NIRTI system (CariVu) may serve as an adjunct to BWXR in the diagnosis of proximal caries. The NIRTI system could serve as an adjunct diagnostic system that could be used in high-caries risk programs where patients are closely monitored with regimented follow-up appointments. NIRTI could also be beneficial with pregnant or pediatric patients, and in situations where radiography may not be available such as remote humanitarian missions. © 2017 Wiley Periodicals, Inc.

Non-destructive investigation of a time capsule using neutron radiography and X-ray fluorescence

NASA Astrophysics Data System (ADS)

MacDonald, B. L.; Vanderstelt, J.; O'Meara, J.; McNeill, F. E.

2016-01-01

Non-destructive analytical techniques are becoming increasingly important for the study of objects of cultural heritage interest. This study applied two techniques: X-ray fluorescence and neutron radiography, for the investigation of a capped, tubular metal object recovered from an urban construction site in Gore Park, Hamilton, Canada. The site is an urban park containing a World War I commemorative monument that underwent renovation and relocation. Historical documentation suggested that the object buried underneath the monument was a time capsule containing a paper document listing the names of 1800 Canadians who died during WWI. The purpose of this study was to assess the condition of the object, and to verify if it was what the historical records purported. XRF analysis was used to characterize the elemental composition of the metal artifact, while neutron radiography revealed that its contents were congruent with historical records and remained intact after being interred for 91 years. Results of this study demonstrate the value of non-destructive techniques for the analysis and preservation of cultural heritage.

Diagnostic Accuracy of Cone-beam Computed Tomography and Conventional Radiography on Apical Periodontitis: A Systematic Review and Meta-analysis.

PubMed

Leonardi Dutra, Kamile; Haas, Letícia; Porporatti, André Luís; Flores-Mir, Carlos; Nascimento Santos, Juliana; Mezzomo, Luis André; Corrêa, Márcio; De Luca Canto, Graziela

2016-03-01

Endodontic diagnosis depends on accurate radiographic examination. Assessment of the location and extent of apical periodontitis (AP) can influence treatment planning and subsequent treatment outcomes. Therefore, this systematic review and meta-analysis assessed the diagnostic accuracy of conventional radiography and cone-beam computed tomographic (CBCT) imaging on the discrimination of AP from no lesion. Eight electronic databases with no language or time limitations were searched. Articles in which the primary objective was to evaluate the accuracy (sensitivity and specificity) of any type of radiographic technique to assess AP in humans were selected. The gold standard was the histologic examination for actual AP (in vivo) or in situ visualization of bone defects for induced artificial AP (in vitro). Accuracy measurements described in the studies were transformed to construct receiver operating characteristic curves and forest plots with the aid of Review Manager v.5.2 (The Nordic Cochrane Centre, Copenhagen, Denmark) and MetaDisc v.1.4. software (Unit of Clinical Biostatistics Team of the Ramón y Cajal Hospital, Madrid, Spain). The methodology of the selected studies was evaluated using the Quality Assessment Tool for Diagnostic Accuracy Studies-2. Only 9 studies met the inclusion criteria and were subjected to a qualitative analysis. A meta-analysis was conducted on 6 of these articles. All of these articles studied artificial AP with induced bone defects. The accuracy values (area under the curve) were 0.96 for CBCT imaging, 0.73 for conventional periapical radiography, and 0.72 for digital periapical radiography. No evidence was found for panoramic radiography. Periapical radiographs (digital and conventional) reported good diagnostic accuracy on the discrimination of artificial AP from no lesions, whereas CBCT imaging showed excellent accuracy values. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

In Vivo Dark-Field Radiography for Early Diagnosis and Staging of Pulmonary Emphysema.

PubMed

Hellbach, Katharina; Yaroshenko, Andre; Meinel, Felix G; Yildirim, Ali Ö; Conlon, Thomas M; Bech, Martin; Mueller, Mark; Velroyen, Astrid; Notohamiprodjo, Mike; Bamberg, Fabian; Auweter, Sigrid; Reiser, Maximilian; Eickelberg, Oliver; Pfeiffer, Franz

2015-07-01

The aim of this study was to evaluate the suitability of in vivo x-ray dark-field radiography for early-stage diagnosis of pulmonary emphysema in mice. Furthermore, we aimed to analyze how the dark-field signal correlates with morphological changes of lung architecture at distinct stages of emphysema. Female 8- to 10-week-old C57Bl/6N mice were used throughout all experiments. Pulmonary emphysema was induced by orotracheal injection of porcine pancreatic elastase (80-U/kg body weight) (n = 30). Control mice (n = 11) received orotracheal injection of phosphate-buffered saline. To monitor the temporal patterns of emphysema development over time, the mice were imaged 7, 14, or 21 days after the application of elastase or phosphate-buffered saline. X-ray transmission and dark-field images were acquired with a prototype grating-based small-animal scanner. In vivo pulmonary function tests were performed before killing the animals. In addition, lungs were obtained for detailed histopathological analysis, including mean cord length (MCL) quantification as a parameter for the assessment of emphysema. Three blinded readers, all of them experienced radiologists and familiar with dark-field imaging, were asked to grade the severity of emphysema for both dark-field and transmission images. Histopathology and MCL quantification confirmed the introduction of different stages of emphysema, which could be clearly visualized and differentiated on the dark-field radiograms, whereas early stages were not detected on transmission images. The correlation between MCL and dark-field signal intensities (r = 0.85) was significantly higher than the correlation between MCL and transmission signal intensities (r = 0.37). The readers' visual ratings for dark-field images correlated significantly better with MCL (r = 0.85) than visual ratings for transmission images (r = 0.36). Interreader agreement and the diagnostic accuracy of both quantitative and visual assessment were significantly higher

Towards a muon radiography of the Puy de Dôme

NASA Astrophysics Data System (ADS)

Cârloganu, C.; Niess, V.; Béné, S.; Busato, E.; Dupieux, P.; Fehr, F.; Gay, P.; Miallier, D.; Vulpescu, B.; Boivin, P.; Combaret, C.; Labazuy, P.; Laktineh, I.; Lénat, J.-F.; Mirabito, L.; Portal, A.

2013-02-01

High-energy (above a few hundred GeV) atmospheric muons are a natural probe for geophysical studies. They can travel through kilometres of rock allowing for a radiography of the density distribution within large structures, like mountains or volcanoes. A collaboration between volcanologists, astroparticle and particle physicists, Tomuvol was formed in 2009 to study tomographic muon imaging of volcanoes with high-resolution, large-scale tracking detectors. We report on two campaigns of measurements at the flank of the Puy de Dôme using glass resistive plate chambers (GRPCs) developed for particle physics, within the CALICE collaboration.

BBU design of linear induction accelerator cells for radiography application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shang, C.C.; Chen, Y.J.; Gaporaso, G.J.

1997-05-06

There is an ongoing effort to develop accelerating modules for high-current electron accelerators for advanced radiography application. Accelerating modules with low beam-cavity coupling impedances along with gap designs with acceptable field stresses comprise a set of fundamental design criteria. We examine improved cell designs which have been developed for accelerator application in several radiographic operating regimes. We evaluate interaction impedances, analyze the effects of beam structure coupling on beam dynamics (beam break-up instability and corkscrew motion). We also provide estimates of coupling through interesting new high-gradient insulators and evaluate their potential future application in induction cells.

Simulation of a complete X-ray digital radiographic system for industrial applications.

PubMed

Nazemi, E; Rokrok, B; Movafeghi, A; Choopan Dastjerdi, M H

2018-05-19

Simulating X-ray images is of great importance in industry and medicine. Using such simulation permits us to optimize parameters which affect image's quality without the limitations of an experimental procedure. This study revolves around a novel methodology to simulate a complete industrial X-ray digital radiographic system composed of an X-ray tube and a computed radiography (CR) image plate using Monte Carlo N Particle eXtended (MCNPX) code. In the process of our research, an industrial X-ray tube with maximum voltage of 300 kV and current of 5 mA was simulated. A 3-layer uniform plate including a polymer overcoat layer, a phosphor layer and a polycarbonate backing layer was also defined and simulated as the CR imaging plate. To model the image formation in the image plate, at first the absorbed dose was calculated in each pixel inside the phosphor layer of CR imaging plate using the mesh tally in MCNPX code and then was converted to gray value using a mathematical relationship determined in a separate procedure. To validate the simulation results, an experimental setup was designed and the images of two step wedges created out of aluminum and steel were captured by the experiments and compared with the simulations. The results show that the simulated images are in good agreement with the experimental ones demonstrating the ability of the proposed methodology for simulating an industrial X-ray imaging system. Copyright © 2018 Elsevier Ltd. All rights reserved.

Micro-XRF complemented by x-radiography and digital microscopy imaging for the study of hidden paintings

NASA Astrophysics Data System (ADS)

Gasanova, Svetlana; Hermon, Sorin

2017-07-01

The present study describes a novel approach to the study of hidden by integrating the non-invasive micro-X-Ray Fluorescence spectroscopy, X-radiography and digital microscopy. The case study analysed is a portrait of a male figure discovered under the painting of Ecce Homo, attributed to Titian's studio with an estimated date in the 1550s. The X-radiography images exposed the details of the underpainting, which appeared to be a nearly finished portrait of a standing man, overpainted by the current composition of Ecce Homo at a 180° angle. The microscopy observations of the upper painting's cracks and flaked areas enabled the study of the exposed underlayers in terms of their colour appearance and pigment particles. The subsequent pigment analysis was performed by micro-XRF. Since the described XRF analysis was performed not in scanner mode, the correct selection of the measurement spots for the micro analysis and separation between pigments of the lower and the upper painting was of paramount importance. The described approach for spot selection was based on the results of the preceding X-radiography and digital microscopy tests. The presence of lead white, vermilion, copper green and iron earth in the underlying portrait was confirmed by the multiple point XRF analysis of Pb, Hg, Cu, Fe and Mn lines. The described investigation method proved to be useful in the identification of the pigments of the underlying painting and consequently assisted in the tentative reconstruction of its colour palette. Moreover, the undertaken approach allowed discovering the potential of micro-XRF technique in the study of hidden compositions.

Dynamic dual-energy chest radiography: a potential tool for lung tissue motion monitoring and kinetic study

PubMed Central

Xu, Tong; Ducote, Justin L.; Wong, Jerry T.; Molloi, Sabee

2011-01-01

Dual-energy chest radiography has the potential to provide better diagnosis of lung disease by removing the bone signal from the image. Dynamic dual-energy radiography is now possible with the introduction of digital flat panel detectors. The purpose of this study is to evaluate the feasibility of using dynamic dual-energy chest radiography for functional lung imaging and tumor motion assessment. The dual energy system used in this study can acquire up to 15 frame of dual-energy images per second. A swine animal model was mechanically ventilated and imaged using the dual-energy system. Sequences of soft-tissue images were obtained using dual-energy subtraction. Time subtracted soft-tissue images were shown to be able to provide information on regional ventilation. Motion tracking of a lung anatomic feature (a branch of pulmonary artery) was performed based on an image cross-correlation algorithm. The tracking precision was found to be better than 1 mm. An adaptive correlation model was established between the above tracked motion and an external surrogate signal (temperature within the tracheal tube). This model is used to predict lung feature motion using the continuous surrogate signal and low frame rate dual-energy images (0.1 to 3.0 frames /sec). The average RMS error of the prediction was (1.1 ± 0.3) mm. The dynamic dual-energy was shown to be potentially useful for lung functional imaging such as regional ventilation and kinetic studies. It can also be used for lung tumor motion assessment and prediction during radiation therapy. PMID:21285477

Dynamic dual-energy chest radiography: a potential tool for lung tissue motion monitoring and kinetic study.

PubMed

Xu, Tong; Ducote, Justin L; Wong, Jerry T; Molloi, Sabee

2011-02-21

Dual-energy chest radiography has the potential to provide better diagnosis of lung disease by removing the bone signal from the image. Dynamic dual-energy radiography is now possible with the introduction of digital flat-panel detectors. The purpose of this study is to evaluate the feasibility of using dynamic dual-energy chest radiography for functional lung imaging and tumor motion assessment. The dual-energy system used in this study can acquire up to 15 frames of dual-energy images per second. A swine animal model was mechanically ventilated and imaged using the dual-energy system. Sequences of soft-tissue images were obtained using dual-energy subtraction. Time subtracted soft-tissue images were shown to be able to provide information on regional ventilation. Motion tracking of a lung anatomic feature (a branch of pulmonary artery) was performed based on an image cross-correlation algorithm. The tracking precision was found to be better than 1 mm. An adaptive correlation model was established between the above tracked motion and an external surrogate signal (temperature within the tracheal tube). This model is used to predict lung feature motion using the continuous surrogate signal and low frame rate dual-energy images (0.1-3.0 frames per second). The average RMS error of the prediction was (1.1 ± 0.3) mm. The dynamic dual energy was shown to be potentially useful for lung functional imaging such as regional ventilation and kinetic studies. It can also be used for lung tumor motion assessment and prediction during radiation therapy.

Evaluation of digital radiography practice using exposure index tracking

PubMed Central

Zhou, Yifang; Allahverdian, Janet; Nute, Jessica L.; Lee, Christina

2016-01-01

Some digital radiography (DR) detectors and software allow for remote download of exam statistics, including image reject status, body part, projection, and exposure index (EI). The ability to have automated data collection from multiple DR units is conducive to a quality control (QC) program monitoring institutional radiographic exposures. We have implemented such a QC program with the goal to identify outliers in machine radiation output and opportunities for improvement in radiation dose levels. We studied the QC records of four digital detectors in greater detail on a monthly basis for one year. Although individual patient entrance skin exposure varied, the radiation dose levels to the detectors were made to be consistent via phototimer recalibration. The exposure data stored on each digital detector were periodically downloaded in a spreadsheet format for analysis. EI median and standard deviation were calculated for each protocol (by body part) and EI histograms were created for torso protocols. When histograms of EI values for different units were compared, we observed differences up to 400 in average EI (representing 60% difference in radiation levels to the detector) between units nominally calibrated to the same EI. We identified distinct components of the EI distributions, which in some cases, had mean EI values 300 apart. Peaks were observed at the current calibrated EI, a previously calibrated EI, and an EI representing computed radiography (CR) techniques. Our findings in this ongoing project have allowed us to make useful interventions, from emphasizing the use of phototimers instead of institutional memory of manual techniques to improvements in our phototimer calibration. We believe that this QC program can be implemented at other sites and can reveal problems with radiation levels in the aggregate that are difficult to identify on a case‐by‐case basis. PACS number(s): 87.59.bf PMID:27929507

The value of thyroid shielding in intraoral radiography

PubMed Central

Hazenoot, Bart; Sanderink, Gerard C H; Berkhout, W Erwin R

2016-01-01

Objectives: To evaluate the utility of the application of a thyroid shield in intraoral radiography when using rectangular collimation. Methods: Experimental data were obtained by measuring the absorbed dose at the position of the thyroid gland in a RANDO® (The Phantom Laboratory, Salem, NY) male phantom with a dosemeter. Four protocols were tested: round collimation and rectangular collimation, both with and without thyroid shield. Five exposure positions were deployed: upper incisor (Isup), upper canine (Csup), upper premolar (Psup), upper molar (Msup) and posterior bitewing (BW). Exposures were made with 70 kV and 7 mA and were repeated 10 times. The exposure times were as recommended for the exposure positions for the respective collimator type by the manufacturer for digital imaging. The data were statistically analyzed with a three-way ANOVA test. Significance was set at p < 0.01. Results: The ANOVA test revealed that the differences between mean doses of all protocols and geometries were statistically significant, p < 0.001. For the Isup, thyroid dose levels were comparable with both collimators at a level indicating primary beam exposure. Thyroid shield reduced this dose with circa 75%. For the Csup position, round collimation also revealed primary beam exposure, and thyroid shield yield was 70%. In Csup with rectangular collimation, the thyroid dose was reduced with a factor 4 compared with round collimation and thyroid shield yielded an additional 42% dose reduction. The thyroid dose levels for the Csup, Psup, Msup and BW exposures were lower with rectangular collimation without thyroid shield than with round collimation with thyroid shield. With rectangular collimation, the thyroid shield in Psup, Msup and BW reduced the dose 10% or less, where dose levels were already low, implying no clinical significance. Conclusions: For the exposures in the upper anterior region, thyroid shield results in an important dose reduction for the thyroid. For

Pulmonary disease in cystic fibrosis: assessment with chest CT at chest radiography dose levels.

PubMed

Ernst, Caroline W; Basten, Ines A; Ilsen, Bart; Buls, Nico; Van Gompel, Gert; De Wachter, Elke; Nieboer, Koenraad H; Verhelle, Filip; Malfroot, Anne; Coomans, Danny; De Maeseneer, Michel; de Mey, Johan

2014-11-01

To investigate a computed tomographic (CT) protocol with iterative reconstruction at conventional radiography dose levels for the assessment of structural lung abnormalities in patients with cystic fibrosis ( CF cystic fibrosis ). In this institutional review board-approved study, 38 patients with CF cystic fibrosis (age range, 6-58 years; 21 patients <18 years and 17 patients >18 years) underwent investigative CT (at minimal exposure settings combined with iterative reconstruction) as a replacement of yearly follow-up posteroanterior chest radiography. Verbal informed consent was obtained from all patients or their parents. CT images were randomized and rated independently by two radiologists with use of the Bhalla scoring system. In addition, mosaic perfusion was evaluated. As reference, the previous available conventional chest CT scan was used. Differences in Bhalla scores were assessed with the χ(2) test and intraclass correlation coefficients ( ICC intraclass correlation coefficient s). Radiation doses for CT and radiography were assessed for adults (>18 years) and children (<18 years) separately by using technical dose descriptors and estimated effective dose. Differences in dose were assessed with the Mann-Whitney U test. The median effective dose for the investigative protocol was 0.04 mSv (95% confidence interval [ CI confidence interval ]: 0.034 mSv, 0.10 mSv) for children and 0.05 mSv (95% CI confidence interval : 0.04 mSv, 0.08 mSv) for adults. These doses were much lower than those with conventional CT (median: 0.52 mSv [95% CI confidence interval : 0.31 mSv, 3.90 mSv] for children and 1.12 mSv [95% CI confidence interval : 0.57 mSv, 3.15 mSv] for adults) and of the same order of magnitude as those for conventional radiography (median: 0.012 mSv [95% CI confidence interval : 0.006 mSv, 0.022 mSv] for children and 0.012 mSv [95% CI confidence interval : 0.005 mSv, 0.031 mSv] for adults). All images were rated at least as diagnostically acceptable

Comparison of radiography and ultrasonography in the detection of lung and liver cysts in cattle and buffaloes

PubMed Central

Kumar, Ashwani; Saini, Narinder Singh; Mohindroo, Jitender; Singh, Balbir Bagicha; Sangwan, Vandana; Sood, Naresh Kumar

2016-01-01

Aim: Echinococcosis is the major cause of lung and liver cysts in ruminants. This study compared usefulness of radiography and ultrasonography (USG) in the detection of lung and/or liver cysts in sick bovine animals. The study also worked out cooccurrence of lung and liver cysts, and whether these cysts were primary cause of sickness or not. Materials and Methods: This study was conducted on 45 sick bovine (37 buffaloes and 8 cattle) suffering from lung and liver cysts. A complete history of illness and clinical examination was carried out. Lateral radiographs of chest and reticular region were taken. In radiographically positive or suspected cases of cysts, USG of the lung and liver region was done. Depending on the location of cyst and clinical manifestations of the animal, the cysts were categorized as primary or secondary causes of sickness. Results: Using either imaging technique, it was observed that 46.7% of the animals had both lung and liver cysts, whereas 33.3% had only lung and 20% had only liver cyst. Cysts were identified as primary cause of sickness in 31.1% animals only. For diagnosing lung cysts, radiography (71.1%) and USG (62.2%) had similar diagnostic utility. However, for detecting liver cysts, USG was the only imaging tool. Conclusion: The lung and liver cysts, depending on their number and size may be a primary cause of sickness in bovine. Radiography and USG are recommended, in combination, as screening tools to rule out echinococcosis. PMID:27847421

Applications of Cosmic Ray Muon Radiography

NASA Astrophysics Data System (ADS)

Guardincerri, E.; Durham, J. M.; Morris, C. L.; Rowe, C. A.; Poulson, D. C.; Bacon, J. D.; Plaud-Ramos, K.; Morley, D. J.

2015-12-01

The Dome of Santa Maria del Fiore, Florence Cathedral, was built between 1420 and 1436 by architect Filippo Brunelleschi and it is now cracking under its own weight. Engineering efforts are underway to model the dome's structure and reinforce it against further deterioration. According to some scholars, Brunelleschi might have built reinforcement structures into the dome itself; however, the only confirmed known subsurface reinforcement is a chain of iron and stone around the dome's base. Tomography with cosmic ray muons is a non-destructive imaging method that can be used to image the interior of the wall and therefore ascertain the layout and status of any iron substructure in the dome. We will show the results from a muon tomography measurement of iron hidden in a mockup of the dome's wall performed at Los Alamos National Lab in 2015. The sensitivity of this technique, and the status of this project will be also discussed. At last, we will show results on muon attenuation radiography of larger shallow targets.

Evaluation of Deblur Methods for Radiography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wood, William M.

2014-03-31

Radiography is used as a primary diagnostic for dynamic experiments, providing timeresolved radiographic measurements of areal mass density along a line of sight through the experiment. It is well known that the finite spot extent of the radiographic source, as well as scattering, are sources of blurring of the radiographic images. This blurring interferes with quantitative measurement of the areal mass density. In order to improve the quantitative utility of this diagnostic, it is necessary to deblur or “restore” the radiographs to recover the “true” areal mass density from a radiographic transmission measurement. Towards this end, I am evaluating threemore » separate methods currently in use for deblurring radiographs. I begin by briefly describing the problems associated with image restoration, and outlining the three methods. Next, I illustrate how blurring affects the quantitative measurements using radiographs. I then present the results of the various deblur methods, evaluating each according to several criteria. After I have summarized the results of the evaluation, I give a detailed account of how the restoration process is actually implemented.« less

Proton radiography measurements and models of ejecta structure in shocked Sn

NASA Astrophysics Data System (ADS)

Hammerberg, J. E.; Buttler, W. T.; Llobet, A.; Morris, C.; Goett, J.; Manzanares, R.; Saunders, A.; Schmidt, D.; Tainter, A.; Vogan-McNeil, W.; Wilde, C.

2017-06-01

We discuss experimental validation of ejecta source mass and velocity models using proton radiography. We have performed ejecta measurements at the Los Alamos proton radiography facility on 7 mm thick 81 mm diameter Sn samples driven with a plane-wave high explosive lens (PBX9501 + TNT). The surface of the Sn, in contact with He gas at an initial pressure of 7 atmospheres, was machined to have 4 concentric sinusoidal features with a wavelength of λ = 2 mm in the radial direction and amplitude h0 = 0.159 mm (kh0 = 2 πh0 / λ = 0.5). The shock pressure was 27 GPa. 42 images were obtained between 0 and 14 μs from the time of shock breakout at 275 and 400 ns intervals. The Abel inverted density profiles evolve to a self-similar density distribution that depends on a scaling variable z /vs t where vs is the spike tip velocity, z is the distance from the free surface and t is the time after shock breakout. Both the density profiles and the time dependence of the mass per unit area in the evolving spikes are in good agreement with a Richtmyer-Meshkov instability based model for ejecta production and evolution. This work was performed under the auspices of the U.S. Dept. of Energy under contract DE-AC52-06NA25396. The support of the LANL ASC-PEM and Science Campaign 2 programs is gratefully acknowledged.

Preliminary clinical evaluation of hard- and soft-copy digitized chest radiography

NASA Astrophysics Data System (ADS)

Rian, Roger L.; Smerud, Michael J.; Guinn, Todd

1994-05-01

The digital applications in radiology are a controversial advanced which potentially will influence all areas of patient imaging. It is utilized and accepted in angiography, computed tomography, magnetic resonance, nuclear imaging and sonography. More recently Computed Radiography has gained credibility in mobile scenarios as well as specific applications from cervical spine radiography to digital fluoroscopy. Usually this acceptance is related to benefits of lesser radiation exposure or an improved presentation with an incorrect radiographic technique. One advantage of interpreting from digital information is the potential manipulation of the image presentation to the observer through windowing, leveling and edge enhancement pre and/or during image review. Additionally this digital data can be transmitted over distance and represented as hard and/or soft copy for primary or consultative review. The number and quality of the images to be viewed, the environment of the review station as well as the observer experience with conventional radiographic as well as digital image evaluation are important aspects of delivering the radiologist's product i.e. the final interpretation. This paper assesses that product, specifically addressing the question `Is the radiologist's report the same whether derived from the original analog image or from its digitized image.' The object of this study is to determine whether a digital system (3M PACS) designed for consultative viewing in a satellite department can also be used directly for primary diagnosis of conventional chest exams.

Multi-energy method of digital radiography for imaging of biological objects

NASA Astrophysics Data System (ADS)

Ryzhikov, V. D.; Naydenov, S. V.; Opolonin, O. D.; Volkov, V. G.; Smith, C. F.

2016-03-01

This work has been dedicated to the search for a new possibility to use multi-energy digital radiography (MER) for medical applications. Our work has included both theoretical and experimental investigations of 2-energy (2E) and 3- energy (3D) radiography for imaging the structure of biological objects. Using special simulation methods and digital analysis based on the X-ray interaction energy dependence for each element of importance to medical applications in the X-ray range of energy up to 150 keV, we have implemented a quasi-linear approximation for the energy dependence of the X-ray linear mass absorption coefficient μm (E) that permits us to determine the intrinsic structure of the biological objects. Our measurements utilize multiple X-ray tube voltages (50, 100, and 150 kV) with Al and Cu filters of different thicknesses to achieve 3-energy X-ray examination of objects. By doing so, we are able to achieve significantly improved imaging quality of the structure of the subject biological objects. To reconstruct and visualize the final images, we use both two-dimensional (2D) and three-dimensional (3D) palettes of identification. The result is a 2E and/or 3E representation of the object with color coding of each pixel according to the data outputs. Following the experimental measurements and post-processing, we produce a 3D image of the biological object - in the case of our trials, fragments or parts of chicken and turkey.

Application of gamma-ray radiography and gravimetric measurements after accelerated corrosion tests of steel embedded in mortar

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duffó, Gustavo, E-mail: duffo@cnea.gov.ar; Consejo Nacional de Investigaciones Científicas y Técnicas; Universidad Nacional de San Martín, Av. Gral. Paz 1499, 1650 San Martín, Buenos Aires

2015-08-15

The accelerated corrosion by the impressed current technique is widely used in studies of concrete durability since it has the advantage that tests can be carried out within reasonable periods of time. In the present work the relationship between the applied current density and the resulting damage on the reinforcing steel, by applying optical microscopy, scanning electron microscopy, gamma-ray radiography and gravimetric measurements, was studied by means of the implementation of accelerated corrosion tests on reinforced mortar. The results show that the efficiency of the applied current is between 1 and 77%, regardless of the applied current density, the water/cementmore » ratio and the mortar cover depth of the specimens. The results show the applicability of the gamma-ray radiography technique to detect localized corrosion of steel rebars in laboratory specimens.« less

Reduction of radiation dose and imaging costs in scoliosis radiography. Application of large-screen image intensifier photofluorography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manninen, H.; Kiekara, O.; Soimakallio, S.

1988-04-01

Photofluorography using a large-field image intensifier (Siemens Optilux 57) was applied to scoliosis radiography and compared with a full-size rare-earth screen/film technique. When scoliosis radiography (PA-projection) was performed on 25 adolescent patients, the photofluorographs were found to be of comparable diagnostic quality with full-size films. A close correspondence between the imaging techniques was found in the Cobb angle measurements as well as in the grading of rotation with the pedicle method. The use of photofluorography results in a radiation dose reduction of about one-half and considerable savings in direct imaging costs and archive space. In our opinion the method ismore » particularly well-suited for follow-up and screening evaluation of scoliosis, but in tall patients the image field size of 40 x 40 cm restricts its usefulness as initial examination.« less

Recognition and prevention of computed radiography image artifacts.

PubMed

Hammerstrom, Kevin; Aldrich, John; Alves, Len; Ho, Andrew

2006-09-01

Initiated by complaints of image artifacts, a thorough visual and radiographic investigation of 197 Fuji, 35 Agfa, and 37 Kodak computed radiography (CR) cassettes with imaging plates (IPs) in clinical use at four radiology departments was performed. The investigation revealed that the physical deterioration of the cassettes and IPs was more extensive than previously believed. It appeared that many of the image artifacts were the direct result of premature wear of the cassettes and imaging plates. The results indicate that a quality control program for CR cassettes and IPs is essential and should include not only cleaning of the cassettes and imaging plates on a regular basis, but also visual and radiographic image inspection to limit the occurrence of image artifacts and to prolong the life cycle of the CR equipment.

SU-C-204-02: Improved Patient-Specific Optimization of the Stopping Power Calibration for Proton Therapy Planning Using a Single Proton Radiography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rinaldi, I; Ludwig Maximilian University, Garching, DE; Heidelberg University Hospital, Heidelberg, DE

2015-06-15

Purpose: We present an improved method to calculate patient-specific calibration curves to convert X-ray computed tomography (CT) Hounsfield Unit (HU) to relative stopping powers (RSP) for proton therapy treatment planning. Methods: By optimizing the HU-RSP calibration curve, the difference between a proton radiographic image and a digitally reconstructed X-ray radiography (DRR) is minimized. The feasibility of this approach has previously been demonstrated. This scenario assumes that all discrepancies between proton radiography and DRR originate from uncertainties in the HU-RSP curve. In reality, external factors cause imperfections in the proton radiography, such as misalignment compared to the DRR and unfaithful representationmore » of geometric structures (“blurring”). We analyze these effects based on synthetic datasets of anthropomorphic phantoms and suggest an extended optimization scheme which explicitly accounts for these effects. Performance of the method is been tested for various simulated irradiation parameters. The ultimate purpose of the optimization is to minimize uncertainties in the HU-RSP calibration curve. We therefore suggest and perform a thorough statistical treatment to quantify the accuracy of the optimized HU-RSP curve. Results: We demonstrate that without extending the optimization scheme, spatial blurring (equivalent to FWHM=3mm convolution) in the proton radiographies can cause up to 10% deviation between the optimized and the ground truth HU-RSP calibration curve. Instead, results obtained with our extended method reach 1% or better correspondence. We have further calculated gamma index maps for different acceptance levels. With DTA=0.5mm and RD=0.5%, a passing ratio of 100% is obtained with the extended method, while an optimization neglecting effects of spatial blurring only reach ∼90%. Conclusion: Our contribution underlines the potential of a single proton radiography to generate a patient-specific calibration curve and to

Magnifying Lenses with Weak Achromatic Bends for High-Energy Electron Radiography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walstrom, Peter Lowell

2015-02-27

This memo briefly describes bremsstrahlung background effects in GeV-range electron radiography systems and the use of weak bending magnets to deflect the image to the side of the forward bremsstrahlung spot to reduce background. The image deflection introduces first-order chromatic image blur due to dispersion. Two approaches to eliminating the dispersion effect to first order by use of magnifying lens with achromatic bends are described. Also, higher-order image blur terms caused by weak bends are also discussed, and shown to be negligibly small in most cases of interest.

Value of stress ultrasound for the diagnosis of chronic ankle instability compared to manual anterior drawer test, stress radiography, magnetic resonance imaging, and arthroscopy.

PubMed

Cho, Jae Ho; Lee, Doo Hyung; Song, Hyung Keun; Bang, Joon Young; Lee, Kyung Tai; Park, Young Uk

2016-04-01

Clinicians frequently diagnose chronic ankle instability using the manual anterior drawer test and stress radiography. However, both examinations can yield incorrect results and do not reveal the extent of ankle instability. Stress ultrasound has been reported to be a new diagnostic tool for the diagnosis of chronic ankle instability. The purpose of this study was to assess the diagnostic value of stress ultrasound for chronic ankle instability compared to the manual anterior drawer test, stress radiography, magnetic resonance imaging (MRI), and arthroscopy. Twenty-eight consecutive patients who underwent ankle arthroscopy and subsequent modified Broström repair for treatment of chronic ankle instability were included. The arthroscopic findings were used as the reference standard. A standardized physical examination (manual anterior drawer test), stress radiography, MRI, and stress ultrasound were performed to assess the anterior talofibular ligament (ATFL) prior to operation. Ultrasound images were taken in the resting position and the maximal anterior drawer position. Grade 3 lateral instability was verified arthroscopically in all 28 cases with a clinical diagnosis (100%). Twenty-two cases showed grade III instability on the manual anterior drawer test (78.6%). Twenty-four cases displayed anterior translation exceeding 5 mm on stress radiography (86%), and talar tilt angle exceeded 15° in three cases (11 %). Nineteen cases displayed a partial chronic tear (change in thickness or signal intensity), and nine cases displayed complete tear on MRI (100%). Lax and wavy ATFL was evident on stress ultrasound in all cases (100 %). The mean value of the ATFL length was 2.8 ± 0.3 cm for the stressed condition and 2.1 ± 0.2 cm for the resting condition (p < 0.001). Stress ultrasound may be useful for the diagnosis of chronic ankle instability in addition to the manual anterior drawer test and stress radiography. III.

Defect detection of castings in radiography images using a robust statistical feature.

PubMed

Zhao, Xinyue; He, Zaixing; Zhang, Shuyou

2014-01-01

One of the most commonly used optical methods for defect detection is radiographic inspection. Compared with methods that extract defects directly from the radiography image, model-based methods deal with the case of an object with complex structure well. However, detection of small low-contrast defects in nonuniformly illuminated images is still a major challenge for them. In this paper, we present a new method based on the grayscale arranging pairs (GAP) feature to detect casting defects in radiography images automatically. First, a model is built using pixel pairs with a stable intensity relationship based on the GAP feature from previously acquired images. Second, defects can be extracted by comparing the difference of intensity-difference signs between the input image and the model statistically. The robustness of the proposed method to noise and illumination variations has been verified on casting radioscopic images with defects. The experimental results showed that the average computation time of the proposed method in the testing stage is 28 ms per image on a computer with a Pentium Core 2 Duo 3.00 GHz processor. For the comparison, we also evaluated the performance of the proposed method as well as that of the mixture-of-Gaussian-based and crossing line profile methods. The proposed method achieved 2.7% and 2.0% false negative rates in the noise and illumination variation experiments, respectively.

Lumbar spine radiography — poor collimation practices after implementation of digital technology

PubMed Central

Zetterberg, L G; Espeland, A

2011-01-01

Objectives The transition from analogue to digital radiography may have reduced the motivation to perform proper collimation, as digital techniques have made it possible to mask areas irradiated outside the area of diagnostic interest (ADI). We examined the hypothesis that collimation practices have deteriorated since digitalisation. Methods After defining the ADI, we compared the proportion of the irradiated field outside the ADI in 86 digital and 86 analogue frontal lumbar spine radiographs using the Mann–Whitney test. 50 digital images and 50 analogue images were from a Norwegian hospital and the remainder from a Danish hospital. Consecutive digital images were compared with analogue images (from the hospitals' archives) produced in the 4 years prior to digitalisation. Both hospitals' standard radiographic procedures remained unchanged during the study. For digital images, the irradiated field was assessed using non-masked raw-data images. Results The proportion of the irradiated field outside the ADI was larger in digital than in analogue images (mean 61.7% vs 42.4%, p<0.001), and also in a subsample of 39 image pairs that could be matched for patient age (p<0.001). The mean total field size was 46% larger in digital than in analogue images (791 cm2 vs 541 cm2). Conclusion Following the implementation of digital radiography, considerably larger areas were irradiated. This causes unnecessarily high radiation doses to patients. PMID:21606070

Experimental detection of upward-going cosmic particles and consequences for correction of density radiography of volcanoes

NASA Astrophysics Data System (ADS)

Jourde, Kevin; Gibert, Dominique; Marteau, Jacques; de Bremond d'Ars, Jean; Gardien, Serge; Girerd, Claude; Ianigro, Jean-Christophe; Carbone, Daniele

2014-05-01

Muon tomography measures the flux of cosmic muons crossing geological bodies to determine their density. Three acquisitions with different sights of view were made at la soufrière de Guadeloupe. All of them show important density fluctuations and reveal the volcano phreatic system. The telescopes used to perform these measurements are exposed to noise fluxes with high intensities relative to the tiny flux of interest. We give experimental evidences ofa so far never described source of noise caused by a flux of upward-going particles. Data acquired on La soufrière of Guadeloupe and Mount Etna reveal that upward-going particles are detected only when the rear side of the telescope is exposed to a wide volume of atmosphere located below the altitude of the telescope and with a rock obstruction less than several tens of meters. Biases produced on density muon radiographies by upward-going fluxes are quantified and correction procedures are applied to radiographies of la soufrière.

Prevalence and Clinical Import of Thoracic Injury Identified by Chest Computed Tomography but Not Chest Radiography in Blunt Trauma: Multicenter Prospective Cohort Study.

PubMed

Langdorf, Mark I; Medak, Anthony J; Hendey, Gregory W; Nishijima, Daniel K; Mower, William R; Raja, Ali S; Baumann, Brigitte M; Anglin, Deirdre R; Anderson, Craig L; Lotfipour, Shahram; Reed, Karin E; Zuabi, Nadia; Khan, Nooreen A; Bithell, Chelsey A; Rowther, Armaan A; Villar, Julian; Rodriguez, Robert M

2015-12-01

Chest computed tomography (CT) diagnoses more injuries than chest radiography, so-called occult injuries. Wide availability of chest CT has driven substantial increase in emergency department use, although the incidence and clinical significance of chest CT findings have not been fully described. We determine the frequency, severity, and clinical import of occult injury, as determined by changes in management. These data will better inform clinical decisions, need for chest CT, and odds of intervention. Our sample included prospective data (2009 to 2013) on 5,912 patients at 10 Level I trauma center EDs with both chest radiography and chest CT at physician discretion. These patients were 40.6% of 14,553 enrolled in the parent study who had either chest radiography or chest CT. Occult injuries were pneumothorax, hemothorax, sternal or greater than 2 rib fractures, pulmonary contusion, thoracic spine or scapula fracture, and diaphragm or great vessel injury found on chest CT but not on preceding chest radiography. A priori, we categorized thoracic injuries as major (having invasive procedures), minor (observation or inpatient pain control >24 hours), or of no clinical significance. Primary outcome was prevalence and proportion of occult injury with major interventions of chest tube, mechanical ventilation, or surgery. Secondary outcome was minor interventions of admission rate or observation hours because of occult injury. Two thousand forty-eight patients (34.6%) had chest injury on chest radiography or chest CT, whereas 1,454 of these patients (71.0%, 24.6% of all patients) had occult injury. Of these, in 954 patients (46.6% of injured, 16.1% of total), chest CT found injuries not observed on immediately preceding chest radiography. In 500 more patients (24.4% of injured patients, 8.5% of all patients), chest radiography found some injury, but chest CT found occult injury. Chest radiography found all injuries in only 29.0% of injured patients. Two hundred and two

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

PubMed

Yousefifard, Mahmoud; Baikpour, Masoud; Ghelichkhani, Parisa; Asady, Hadi; Shahsavari Nia, Kavous; Moghadas Jafari, Ali; Hosseini, Mostafa; Safari, Saeed

2016-01-01

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

SU-E-J-158: Experimental Investigation of Proton Radiography Based On Time-Resolved Dose Measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Testa, M; Paganetti, H; Lu, H-M

2014-06-01

Purpose: To use proton radiography for i) in-vivo range verification of the brain fields of medulloblastoma patients in order to reduce the exit dose to the cranial skin and thus the risk of permanent alopecia; ii) for performing patient specific optimization of the calibration from CT-Hounsfield units to proton relative stopping power in order to minimize uncertainties of proton rang Methods: We developed and tested a prototype proton radiography system based on a single-plane scintillation screen coupled with a fast CCD camera (1ms sampling rate, 0.29x0.29 mm{sup 2} pixel size, 30×30 cm{sup 2} field of view). The method is basedmore » on the principle that, for passively scattered beams, the radiological depth of any point in the plateau of a spread-out Bragg-Peak (SOBP) can be inferred from the time-pattern of the dose rate measurements. We performed detector characterization measurements using complex-shape homogeneous phantoms and an Alderson phanto Results: Detector characterization tests confirmed the robustness of the technique. The results of the phantom measurements are encouraging in terms of achievable accuracy of the water equivalent thickness. A technique to minimize the degradation of spatial resolution due to multiple Coulomb scattering is discussed. Our novel radiographic technique is rapid (100 ms) and simultaneous over the whole field. The dose required to produce one radiograph, with the current settings, is ∼3 cG Conclusion: The results obtained with this simple and innovative radiography method are promising and motivate further development of technique. The system requires only a single-plane 2D dosimeter and it uses the clinical beam for a fraction of second with low dose to the patient.« less

An investigation into dental digital radiography in dental practices in West Kent following the introduction of the 2006 NHS General Dental Services contract.

PubMed

Mauthe, Peter W; Eaton, Kenneth A

2011-04-01

The primary aims of the study were to investigate the use of digital radiography within primary dental care practices in the West Kent Primary Care Trust (PCT) area and general dental practitioners' (GDPs) self-reported change in radiographic prescribing patterns following the introduction of the nGDS contract in 2006. Data were gathered via a piloted, self-completed questionnaire, and circulated to all GDPs listed on the National Health Service (NHS) Choices website as practising in the West Kent PCT area. There were three mailings and follow-up telephone calls. The resulting data were entered into a statistical software database and, where relevant, statistically tested, using the chi-square test and Pearson correlation coefficient. Of 223 GDPs, 168 (75%) responded. There were 163 usable questionnaires. The respondents represented 85% of the general dental practices in West Kent. Eighty (49%) respondents were using digital intra-oral radiography. Of those who used digital radiography, 44 (55%) reported that they used phosphor plate systems and 36 (45%) that they used direct digital sensors. Eighty-three (51%) had a panoramic machine in their practice, 46 of whom (55%) were using digital systems; of these, 32 (67%) were using a direct digital system. Seventy-one GDPs reported that they worked exclusively or mainly in private practice. Forty (56%) of these 'mainly private' GDPs reported that they used digital radiographic systems, whereas only 40 (44%) of the 89 'mainly NHS' GDPs reported using digital radio-graphic systems. On average, mainly private GDPs made the transition to a digital radiographic system six months before mainly NHS GDPs. Of those who provided NHS dentistry before and after April 2006, only 18 (14%) reported taking fewer radiographs and seven (6%) taking more. In February 2010, of the West Kent GDPs who responded to the questionnaire, just under 50% used digital radio graphy. Mainly private GDPs were more likely to use digital radiography than

SU-D-209-06: Study On the Dose Conversion Coefficients in Pediatric Radiography with the Development of Children Voxel Phantoms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Q; Shanghai General Hospital, Shanghai, Shanghai; Zhuo, W

Purpose: Conversion coefficients of organ dose normalized to entrance skin dose (ESD) are widely used to evaluate the organ doses directly using ESD without time-consuming dose measurement, this work aims to investigate the dose conversion coefficients in pediatric chest and abdomen radiography with the development of 5 years and 10 years old children voxel phantoms. Methods: After segmentation of organs and tissues from CT slice images of ATOM tissue-equivalent phantoms, a 5-year-old and a 10-year-old children computational voxel phantoms were developed for Monte Carlo simulation. The organ doses and the entrance skin dose for pediatric chest postero-anterior projection and abdominalmore » antero-posterior projection were simulated at the same time, and then the organ dose conversion coefficients were calculated.To verify the simulated results, dose measurement was carried out with ATOM tissue-equivalent phantoms for 5 year chest radiography. Results: Simulated results and experimental results matched very well with each other, the result differences of all the organs covered in radiation field were below 16% for 5-year-old child in chest projection. I showed that the conversion coefficients of organs covered in the radiation field were much larger than organs out of the field for all the study cases, for example, the conversion coefficients of stomach, liver intestines, and pancreas are larger for abdomen radiography while conversion coefficients of lungs are larger for chest radiography. Conclusion: The voxel children phantoms were helpful to evaluate the radiation doses more accurately and efficiently. Radiation field was the essential factor that affects the organ dose, use reasonably small field should be encouraged for radiation protection. This work was supported by the National Natural Science Foundation of China(11475047)« less

Determination of Corrosion Rate of Artificial Bone Made of Metal at Different pH Conditions using X-Ray Radiography

NASA Astrophysics Data System (ADS)

Sutikno; Handayani, L.; Edi, S. S.; Susilo; Elvira

2018-03-01

The purpose of this research is to observe the mechanism and the rate of corrosion of artificial bone made of metal by using x-ray radiography technique. Artificial bones can be made of metallic materials and composites which are biomaterials. The most commonly used metal for bone graft is stainless steel. The interaction between artificial bone and human tissue will have important medical impacts that need to be observed and examined. This interaction can be a mechanical or chemical interaction. X-ray radiography technique is selected because it uses non-destructive method. This method is done by x-ray radiation exposure on the observed body part. The bone density and bone fracture can be seen on the resulted radiographic film or image on the monitor screen.

Non-invasive Differentiation of Kidney Stone Types using X-ray Dark-Field Radiography

PubMed Central

Scherer, Kai; Braig, Eva; Willer, Konstantin; Willner, Marian; Fingerle, Alexander A.; Chabior, Michael; Herzen, Julia; Eiber, Matthias; Haller, Bernhard; Straub, Michael; Schneider, Heike; Rummeny, Ernst J.; Noël, Peter B.; Pfeiffer, Franz

2015-01-01

Treatment of renal calculi is highly dependent on the chemical composition of the stone in question, which is difficult to determine using standard imaging techniques. The objective of this study is to evaluate the potential of scatter-sensitive X-ray dark-field radiography to differentiate between the most common types of kidney stones in clinical practice. Here, we examine the absorption-to-scattering ratio of 118 extracted kidney stones with a laboratory Talbot-Lau Interferometer. Depending on their chemical composition, microscopic growth structure and morphology the various types of kidney stones show strongly varying, partially opposite contrasts in absorption and dark-field imaging. By assessing the microscopic calculi morphology with high resolution micro-computed tomography measurements, we illustrate the dependence of dark-field signal strength on the respective stone type. Finally, we utilize X-ray dark-field radiography as a non-invasive, highly sensitive (100%) and specific (97%) tool for the differentiation of calcium oxalate, uric acid and mixed types of stones, while additionally improving the detectability of radio-lucent calculi. We prove clinical feasibility of the here proposed method by accurately classifying renal stones, embedded within a fresh pig kidney, using dose-compatible measurements and a quick and simple visual inspection. PMID:25873414

Quantitative imaging of single-shot liquid distributions in sprays using broadband flash x-ray radiography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Halls, B. R.; Roy, S.; Gord, J. R.

Flash x-ray radiography is used to capture quantitative, two-dimensional line-of-sight averaged, single-shot liquid distribution measurements in impinging jet sprays. The accuracy of utilizing broadband x-ray radiation from compact flash tube sources is investigated for a range of conditions by comparing the data with radiographic high-speed measurements from a narrowband, high-intensity synchrotron x-ray facility at the Advanced Photon Source (APS) of Argonne National Laboratory. The path length of the liquid jets is varied to evaluate the effects of energy dependent x-ray attenuation, also known as spectral beam hardening. The spatial liquid distributions from flash x-ray and synchrotron-based radiography are compared, alongmore » with spectral characteristics using Taylor’s hypothesis. The results indicate that quantitative, single-shot imaging of liquid distributions can be achieved using broadband x-ray sources with nanosecond temporal resolution. Practical considerations for optimizing the imaging system performance are discussed, including the coupled effects of x-ray bandwidth, contrast, sensitivity, spatial resolution, temporal resolution, and spectral beam hardening.« less

Clinical performance of a prototype flat-panel digital detector for general radiography

NASA Astrophysics Data System (ADS)

Huda, Walter; Scalzetti, Ernest M.; Roskopf, Marsha L.; Geiger, Robert

2001-08-01

Digital radiographs obtained using a prototype Digital Radiography System (Stingray) were compared with those obtained using conventional screen-film. Forty adult volunteers each had two identical radiographs taken at the same level of radiation exposure, one using screen-film and the other the digital detector. Each digital image was processed by hand to ensure that the printed quality was optimal. Ten radiologists compared the diagnostic image quality of the digital images with the corresponding film radiographs using a seven point ranking scheme.

Use and imaging performance of CMOS flat panel imager with LiF/ZnS(Ag) and Gadox scintillation screens for neutron radiography

NASA Astrophysics Data System (ADS)

Cha, B. K.; kim, J. Y.; Kim, T. J.; Sim, C.; Cho, G.; Lee, D. H.; Seo, C.-W.; Jeon, S.; Huh, Y.

2011-01-01

In digital neutron radiography system, a thermal neutron imaging detector based on neutron-sensitive scintillating screens with CMOS(complementary metal oxide semiconductor) flat panel imager is introduced for non-destructive testing (NDT) application. Recently, large area CMOS APS (active-pixel sensor) in conjunction with scintillation films has been widely used in many digital X-ray imaging applications. Instead of typical imaging detectors such as image plates, cooled-CCD cameras and amorphous silicon flat panel detectors in combination with scintillation screens, we tried to apply a scintillator-based CMOS APS to neutron imaging detection systems for high resolution neutron radiography. In this work, two major Gd2O2S:Tb and 6LiF/ZnS:Ag scintillation screens with various thickness were fabricated by a screen printing method. These neutron converter screens consist of a dispersion of Gd2O2S:Tb and 6LiF/ZnS:Ag scintillating particles in acrylic binder. These scintillating screens coupled-CMOS flat panel imager with 25x50mm2 active area and 48μm pixel pitch was used for neutron radiography. Thermal neutron flux with 6x106n/cm2/s was utilized at the NRF facility of HANARO in KAERI. The neutron imaging characterization of the used detector was investigated in terms of relative light output, linearity and spatial resolution in detail. The experimental results of scintillating screen-based CMOS flat panel detectors demonstrate possibility of high sensitive and high spatial resolution imaging in neutron radiography system.

An Overview of the MaRIE X-FEL and Electron Radiography LINAC RF Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bradley, Joseph Thomas III; Rees, Daniel Earl; Scheinker, Alexander

The purpose of the Matter-Radiation Interactions in Extremes (MaRIE) facility at Los Alamos National Laboratory is to investigate the performance limits of materials in extreme environments. The MaRIE facility will utilize a 12 GeV linac to drive an X-ray Free-Electron Laser (FEL). Most of the same linac will also be used to perform electron radiography. The main linac is driven by two shorter linacs; one short linac optimized for X-FEL pulses and one for electron radiography. The RF systems have historically been the one of the largest single component costs of a linac. We will describe the details of themore » different types of RF systems required by each part of the linacs. Starting with the High Power RF system, we will present our methodology for the choice of RF system peak power and pulselength with respect to klystron parameters, modulator parameters, performance requirements and relative costs. We will also present an overview of the Low Level RF systems that are proposed for MaRIE and briefly describe their use with some proposed control schemes.« less

The impact of an early-morning radiologist work shift on the timeliness of communicating urgent imaging findings on portable chest radiography.

PubMed

Kaewlai, Rathachai; Greene, Reginald E; Asrani, Ashwin V; Abujudeh, Hani H

2010-09-01

The aim of this study was to assess the potential impact of staggered radiologist work shifts on the timeliness of communicating urgent imaging findings that are detected on portable overnight chest radiography of hospitalized patients. The authors conducted a retrospective study that compared the interval between the acquisition and communication of urgent findings on portable overnight critical care chest radiography detected by an early-morning shift for radiologists (3 am to 11 am) with historical experience with a standard daytime shift (8 am to 5 pm) in the detection and communication of urgent findings in a similar patient population a year earlier. During a 4-month period, 6,448 portable chest radiographic studies were interpreted on the early-morning radiologist shift. Urgent findings requiring immediate communication were detected in 308 (4.8%) studies. The early-morning shift of radiologists, on average, communicated these findings 2 hours earlier compared with the historical control group (P < .001). Staggered radiologist work shifts that include an early-morning shift can improve the timeliness of reporting urgent findings on overnight portable chest radiography of hospitalized patients. Published by Elsevier Inc.

Use of plain radiography in the diagnosis, surgical management, and postoperative treatment of obstructive urolithiasis in 25 goats and 2 sheep.

PubMed

Kinsley, Marc A; Semevolos, Stacy; Parker, Jill E; Duesterdieck-Zellmer, Katja; Huber, Michael

2013-08-01

To describe use of plain radiography for diagnosis, surgical management, and postoperative treatment of obstructive urolithiasis in small ruminants. Retrospective case series. Small ruminants (n = 27; 25 goats, 2 sheep). Medical records (January 2002-November 2011) and radiographs for all small ruminants diagnosed with obstructive urolithiasis and having plain abdominal radiographs were reviewed. Signalment, surgical procedures, radiographic findings, ultrasonographic findings, position of calculi, and how plain radiography influenced surgical management and postoperative treatment were recorded. Radiopaque urinary calculi were detected in 23 (85%) plain radiographic studies. Location of uroliths determined by plain radiography included: cystic only (n = 5), distal to the sigmoid flexure and cystic (5), subischial (5), distal to the sigmoid flexure only (3), sigmoid flexure (3), and subischial and cystic (2). In 8 of these animals, postoperative radiographs revealed residual calculi in the urethra and were essential for their targeted removal by urethrotomy in 7 animals. In regions where radiopaque calculi (calcium carbonate, calcium oxalate, silica) are commonly encountered in small ruminants, plain radiographs are recommended to determine the appropriate surgical approach(es) and to confirm resolution of the obstruction. © Copyright 2013 by The American College of Veterinary Surgeons.

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

PubMed

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

2016-02-01

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

Can the Ottawa and Pittsburgh rules reduce requests for radiography in patients referred to acute knee clinics?

PubMed Central

Zang, TT; Tamimi, N; Haddad, FS

2013-01-01

Our aim was to study the role of the Ottawa and Pittsburgh rules to reduce the unnecessary use of radiographs following knee injury. We prospectively reviewed 106 patients who were referred to our clinic over a 3-month period. The Ottawa and Pittsburgh rules were applied to individual patients to evaluate the need for radiography. One hundred and one patients (95%) had radiography of their knee. Five patients (5%) had a fracture of their knee and in all cases, the Ottawa and Pittsburgh knee rules were fulfilled. Using the Ottawa rules, 27 radiographs (25%) could have been avoided without missing a fracture. Using the Pittsburgh rules, 32 radiographs (30%) could have been avoided. The Ottawa and Pittsburgh rules have a high sensitivity for the detection of knee fractures. Their use can aid efficient clinical evaluation without adverse clinical outcome and may reduce healthcare costs. PMID:23827289

Can the Ottawa and Pittsburgh rules reduce requests for radiography in patients referred to acute knee clinics?

PubMed

Konan, S; Zang, T T; Tamimi, N; Haddad, F S

2013-04-01

Our aim was to study the role of the Ottawa and Pittsburgh rules to reduce the unnecessary use of radiographs following knee injury. We prospectively reviewed 106 patients who were referred to our clinic over a 3-month period. The Ottawa and Pittsburgh rules were applied to individual patients to evaluate the need for radiography. One hundred and one patients (95%) had radiography of their knee. Five patients (5%) had a fracture of their knee and in all cases, the Ottawa and Pittsburgh knee rules were fulfilled. Using the Ottawa rules, 27 radiographs (25%) could have been avoided without missing a fracture. Using the Pittsburgh rules, 32 radiographs (30%) could have been avoided. The Ottawa and Pittsburgh rules have a high sensitivity for the detection of knee fractures. Their use can aid efficient clinical evaluation without adverse clinical outcome and may reduce healthcare costs.

The use of x-ray radiography for measuring mass distributions of Rocket Injectors

DTIC Science & Technology

2013-06-01

successfully applied to diesel injectors , aerated liquid jets and impinging-jet sprays [7-10]. X-ray radiography can be performed using either a...Rocket Injectors 5a. CONTRACT NUMBER N/A 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) S.A. Schumaker, A.L. Kastengren, M.D.A...measurements for injector design. Unfortunately, the mass flow rates typically encountered in rocket engines create sprays with high optical densities

Advanced-stage Hodgkin lymphoma: US/chest radiography for detection of relapse in patients in first complete remission--a randomized trial of routine surveillance imaging procedures.

PubMed

Picardi, Marco; Pugliese, Novella; Cirillo, Michele; Zeppa, Pio; Cozzolino, Imma; Ciancia, Giuseppe; Pettinato, Guido; Salvatore, Claudia; Quintarelli, Concetta; Pane, Fabrizio

2014-07-01

To compare the use of fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) with the use of a combination of ultrasonography (US) and chest radiography for systematic follow-up of patients with high-risk Hodgkin lymphoma. Institutional review board approval and informed consent were obtained. In a single center between January 2001 and December 2009, patients with advanced-stage Hodgkin lymphoma who had responded completely to first-line treatment were randomly assigned (1:1) to follow-up with either PET/CT or US/chest radiography. Follow-up included clinical and imaging procedures at 4, 8, 12, 16, 20, 24, 30, 36, 48, 60, 84, and 108 months after treatment discontinuation. When clinical and/or imaging results were positive, recurrence was confirmed histologically. The primary endpoint was to compare the sensitivity of the two follow-up imaging approaches. Secondary endpoints were their specificity, positive and negative predictive values, time to recurrence detection, radiation risks, and costs. A total of 300 patients were randomized into the two arms. The study was closed after a median follow-up time of 60 months, with a relapse rate of 27%. Sensitivity for detection of Hodgkin lymphoma was similar for the two follow-up approaches. All of the relapses (40 of 40) were identified with FDG PET/CT (100%) and 39 of 40 relapses were identified with US/chest radiography (97.5%; P = .0001 for the equivalence test). US/chest radiography showed significantly higher specificity and positive predictive value than did PET/CT (96% [106 of 110] vs 86% [95 of 110], respectively; P = .02; and 91% [39 of 43] vs 73% [40 of 55], respectively; P = .01). Exposure to ionizing radiation was estimated to be 14.5 mSv for one PET/CT examination versus 0.1 mSv for one chest radiographic examination. Estimated cost per relapse diagnosed with routine PET/CT was 10-fold higher compared with that diagnosed with routine US/chest radiography. US and

Effect of scaling and root planing on alveolar bone as measured by subtraction radiography.

PubMed

Hwang, You-Jeong; Fien, Matthew Jonas; Lee, Sam-Sun; Kim, Tae-Il; Seol, Yang-Jo; Lee, Yong-Moo; Ku, Young; Rhyu, In-Chul; Chung, Chong-Pyoung; Han, Soo-Boo

2008-09-01

Scaling and root planing of diseased periodontal pockets is fundamental to the treatment of periodontal disease. Although various clinical parameters have been used to assess the efficacy of this therapy, radiographic analysis of changes in bone density following scaling and root planing has not been extensively researched. In this study, digital subtraction radiography was used to analyze changes that occurred in the periodontal hard tissues following scaling and root planing. Thirteen subjects with a total of 39 sites that presented with >3 mm of vertical bone loss were included in this study. Clinical examinations were performed and radiographs were taken prior to treatment and were repeated 6 months following scaling and root planing. Radiographic analysis was performed with computer-assisted radiographic evaluation software. Three regions of interest (ROI) were defined as the most coronal, middle, and apical portions of each defect. A fourth ROI was used for each site as a control region and was placed at a distant, untreated area. Statistical analysis was carried out to evaluate changes in the mean gray level at the coronal, middle, and apical region of each treated defect. Digital subtraction radiography revealed an increase in radiographic density in 101 of the 117 test regions (83.3%). A 256 gray level was used, and a value >128 was assumed to represent a density gain in the ROI. The average gray level increase was 18.65. Although the coronal, middle, and apical regions displayed increases in bone density throughout this study, the bone density of the apical ROI (gray level = 151.27 +/- 20.62) increased significantly more than the bone density of the coronal ROI (gray level = 139.19 +/- 21.78). A significant increase in bone density was seen in probing depths >5 mm compared to those <5 mm in depth. No significant difference was found with regard to bone-density changes surrounding single- versus multiple-rooted teeth. Scaling and root planing of diseased

[Children with minor head injury in the emergency department: Is skull radiography necessary for children under 2 years?].

PubMed

Muñoz-Santanach, David; Trenchs Sainz de la Maza, Victoria; González Forster, Elisa; Luaces Cubells, Carles

2014-01-01

Current guidelines on the management of mild head trauma (traumatic brain injury/TBI) do not include the presence of a skull fracture in determining the risk of intracranial injury. However, in our setting cranial radiography is still performed frequently to rule out the presence of skull fracture. To estimate the prevalence of clinically-important traumatic brain injuries (ciTBI) in children younger than two years of age with mild TBI. Descriptive observational study. All children attended in emergency department with mild TBI (Glasgow ≥14 points) for a year were included. We defined ciTBI as intracranial injuries that caused death or required neurosurgery, intubation for more than 24 hours, inotropic drugs or mechanical ventilation. The study included 854 children, of which 457 (53.5%) were male. The median patient age was 11.0 months (P25-75: 7.5-17.0 months). In 741 cases (86.8%) the mechanism of TBI was a fall. In 438 cases (51.3%) skull radiography was performed. Eleven children (1.3%) had intracranial injury, but none met the criteria for ciTBI (estimated prevalence of ciTBI was 0%; CI 95%: 0%-0.4%). Children younger than two years of age with mild TBI have low prevalence of ciTBI. Consequently, it is possible to monitor children younger than two years with a TBI without performing skull radiography. Copyright © 2013 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

Accuracy of Conventional and Digital Radiography in Detecting External Root Resorption

PubMed Central

Mesgarani, Abbas; Haghanifar, Sina; Ehsani, Maryam; Yaghub, Samereh Dokhte; Bijani, Ali

2014-01-01

Introduction: External root resorption (ERR) is associated with physiological and pathological dissolution of mineralized tissues by clastic cells and radiography is one of the most important methods in its diagnosis. The aim of this experimental study was to evaluate the accuracy of conventional intraoral radiography (CR) in comparison with digital radiographic techniques, i.e. charge-coupled device (CCD) and photo-stimulable phosphor (PSP) sensors, in detection of ERR. Methods and Materials: This study was performed on 80 extracted human mandibular premolars. After taking separate initial periapical radiographs with CR technique, CCD and PSP sensors, the artificial defects resembling ERR with variable sizes were created in apical half of the mesial, distal and buccal surfaces of the teeth. Ten teeth were used as control samples without any resorption. The radiographs were then repeated with 2 different exposure times and the images were observed by 3 observers. Data were analyzed using SPSS version 17 and chi-squared and Cohen’s Kappa tests with 95% confidence interval (CI=95%). Result: The CCD had the highest percentage of correct assessment compared to the CR and PSP sensors, although the difference was not significant (P=0.39). It was shown that the higher dosage of radiation increases the accuracy of diagnosis; however, it was only significant for CCD sensor (P=0.02). Also, the accuracy of diagnosis increased with the increase in the size of lesion (P=0.001). Conclusion: Statistically significant difference was not observed for accurate detection of ERR by conventional and digital radiographic techniques. PMID:25386202

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

PubMed

Rethnam, Ulfin; Yesupalan, Rajam; Gandham, Giri

2008-06-16

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

Pictorial Review of Digital Radiography Artifacts.

PubMed

Walz-Flannigan, Alisa I; Brossoit, Kimberly J; Magnuson, Dayne J; Schueler, Beth A

2018-01-01

Visual familiarity with the variety of digital radiographic artifacts is needed to identify, resolve, or prevent image artifacts from creating issues with patient imaging. Because the mechanism for image creation is different between flat-panel detectors and computed radiography, the causes and appearances of some artifacts can be unique to these different modalities. Examples are provided of artifacts that were found on clinical images or during quality control testing with flat-panel detectors. The examples are meant to serve as learning tools for future identification and troubleshooting of artifacts and as a reminder for steps that can be taken for prevention. The examples of artifacts provided are classified according to their causal connection in the imaging chain, including an equipment defect as a result of an accident or mishandling, debris or gain calibration flaws, a problematic acquisition technique, signal transmission failures, and image processing issues. Specific artifacts include those that are due to flat-panel detector drops, backscatter, debris in the x-ray field during calibration, detector saturation or underexposure, or collimation detection errors, as well as a variety of artifacts that are processing induced. © RSNA, 2018.

Neutron radiography in Indian space programme

NASA Astrophysics Data System (ADS)

Viswanathan, K.

1999-11-01

Pyrotechnic devices are indispensable in any space programme to perform such critical operations as ignition, stage separation, solar panel deployment, etc. The nature of design and configuration of different types of pyrotechnic devices, and the type of materials that are put in their construction make the inspection of them with thermal neutrons more favourable than any other non destructive testing methods. Although many types of neutron sources are available for use, generally the radiographic quality/exposure duration and cost of source run in opposite directions even after four decades of research and development. But in the area of space activity, by suitably combining the X-ray and neutron radiographic requirements, the inspection of the components can be made economically viable. This is demonstrated in the Indian space programme by establishing a 15 MeV linear accelerator based neutron generator facility to inspect medium to giant solid propellant boosters by X-ray inspection and all types of critical pyro and some electronic components by neutron radiography. Since the beam contains unacceptable gamma, transfer imaging technique has been evolved and the various parameters have been optimised to get a good quality image.

42 CFR Appendix B to Part 75 - Standards for Accreditation of Dental Radiography Training for Dental Hygienists

Code of Federal Regulations, 2010 CFR

2010-10-01

... must include content in seven areas: radiation physics; radiation biology; radiation health, safety... 42 Public Health 1 2010-10-01 2010-10-01 false Standards for Accreditation of Dental Radiography Training for Dental Hygienists B Appendix B to Part 75 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF...

Noise power spectrum of the fixed pattern noise in digital radiography detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Dong Sik, E-mail: dskim@hufs.ac.kr; Kim, Eun

Purpose: The fixed pattern noise in radiography image detectors is caused by various sources. Multiple readout circuits with gate drivers and charge amplifiers are used to efficiently acquire the pixel voltage signals. However, the multiple circuits are not identical and thus yield nonuniform system gains. Nonuniform sensitivities are also produced from local variations in the charge collection elements. Furthermore, in phosphor-based detectors, the optical scattering at the top surface of the columnar CsI growth, the grain boundaries, and the disorder structure causes spatial sensitivity variations. These nonuniform gains or sensitivities cause fixed pattern noise and degrade the detector performance, evenmore » though the noise problem can be partially alleviated by using gain correction techniques. Hence, in order to develop good detectors, comparative analysis of the energy spectrum of the fixed pattern noise is important. Methods: In order to observe the energy spectrum of the fixed pattern noise, a normalized noise power spectrum (NNPS) of the fixed pattern noise is considered in this paper. Since the fixed pattern noise is mainly caused by the nonuniform gains, we call the spectrum the gain NNPS. We first asymptotically observe the gain NNPS and then formulate two relationships to calculate the gain NNPS based on a nonuniform-gain model. Since the gain NNPS values are quite low compared to the usual NNPS, measuring such a low NNPS value is difficult. By using the average of the uniform exposure images, a robust measuring method for the gain NNPS is proposed in this paper. Results: By using the proposed measuring method, the gain NNPS curves of several prototypes of general radiography and mammography detectors were measured to analyze their fixed pattern noise properties. We notice that a direct detector, which is based on the a-Se photoconductor, showed lower gain NNPS than the indirect-detector case, which is based on the CsI scintillator. By comparing

Digital radiography density measurements in differentiation between periapical granulomas and radicular cysts.

PubMed

Rózyło-Kalinowska, Ingrid

2007-05-01

The distinction between radicular cysts and apical granulomas is a matter of considerable importance in making a treatment decision. Because there are no clearly defined radiographic criteria, the distinction is made on the grounds of size. However, it has been suggested that cysts can be distinguished from granulomas on the basis of their radiometric density. The results of previous studies have proved conflicting. To determine possibilities of application of digital radiography density measurements in differentiation of periapical granulomas and radicular cysts of inflammatory origin. The material consisted of 355 digital periapical radiograms obtained using Digora, RVG and Dixi 2 digital radiography systems in patients aged 20 to 84, divided into two groups: 259 granulomas and 102 radicular cysts. By means of Digora 2.0 software there were measured maximum and minimum densities along a line, then there was calculated the difference between maximum and minimum density. The largest dimensions of the lesions were measured - perpendicular and parallel to the root canal axis. It was proved that to some extent it was possible to differentiate cystic granulomas and radicular cysts on the basis of the difference between maximum and minimum density in linear measurement - when the difference exceeded 85.6 the lesion was a cyst and when it was below 45.9 a granuloma was diagnosed. Combination of two criteria - the calculated difference between densities and the largest dimension of a lesion, increased diagnostic possibilities of radiological differentiation of granulomas and radicular cysts.