Performance evaluation of a computed radiography system

Energy Technology Data Exchange (ETDEWEB)

Roussilhe, J.; Fallet, E. [Carestream Health France, 71 - Chalon/Saone (France); Mango, St.A. [Carestream Health, Inc. Rochester, New York (United States)

2007-07-01

Computed radiography (CR) standards have been formalized and published in Europe and in the US. The CR system classification is defined in those standards by - minimum normalized signal-to-noise ratio (SNRN), and - maximum basic spatial resolution (SRb). Both the signal-to-noise ratio (SNR) and the contrast sensitivity of a CR system depend on the dose (exposure time and conditions) at the detector. Because of their wide dynamic range, the same storage phosphor imaging plate can qualify for all six CR system classes. The exposure characteristics from 30 to 450 kV, the contrast sensitivity, and the spatial resolution of the KODAK INDUSTREX CR Digital System have been thoroughly evaluated. This paper will present some of the factors that determine the system's spatial resolution performance. (authors)

Computer radiography-X-ray with vision

International Nuclear Information System (INIS)

Waitiki, C.

2006-01-01

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

Digital and analogue industrial radiography, application fields

International Nuclear Information System (INIS)

Willems, Peter; Millord, Erik Yardin

2000-01-01

Full text: Reusable phosphor screens for computer radiography (CR), amorphous selenium screens for direct radiography (DR), film digitalisation (FD) constitute imaging methods accepted by industry and are used for non-destructive radiographic testing (RT). Economic pressures are involving and affecting digital RT technology. Standards and codes for film radiography and radioscopy qualification do no longer cover the wide range of digital RT applications. It will be our task to optimise the performance of digital RT characterisation and to create appropriate examination methods to use all these new and existent technologies. In the meantime, an increasing automation and control of manual methods of analogue radiography can as well be expected. (author)

Image characterization of computed radiography

International Nuclear Information System (INIS)

Candeias, Janaina P.; Saddock, Aline; Oliveira, Davi F.; Lopes, Ricardo T.

2007-01-01

The digital radiographic image became a reality as of the 80's decade. Since then, several works have been developed with the aim of reducing the exposure time to ionizing radiation obtaining in this way an excellent image quality with a minimum exposure. In the Computerized Radiography, the conventional film is substituted for Image Plate (IP) which consists of a radiosensitive layer of phosphor crystals on a polyester backing plate. The unique design makes it reusable and easy to handle. When exposed, the IP accumulates and stores the irradiated radioactive energy. In order to qualify a computerized radiography system it is necessary to evaluate the Image Plate. In this work it was performed a series of experimental procedures with the aim of evaluating the responses characteristics for different plates. For this purpose it was used a computerized radiographic system CR Tower Scanner - GE, with three different types of IPs, all of them manufactured by GE, whose nomenclatures are IPC, IPX and IPS. It was used the Rhythm Acquire and Review programs for image acquisition and treatment, respectively. (author)

Computed radiography for breast cancer

International Nuclear Information System (INIS)

Yamada, Tatsuya; Muramatsu, Yukio

1990-01-01

In order to evaluate the possibility of using computed radiographic mammography in mass surveys of the breast, we have retrospectively examined 71 breast cancer lesions in 71 patients using computed radiographic and conventional non-screen mammographies and have carried out comparative studies on tumor detection rate and calcification. A 95.8% detection rate was obtained for the tumor image (n 71) using computed radiography (CR) and one of 93.0% using non-screen techniques. Three lesions remained undetected by either study. A 100% detection rate was obtained for calcification associated with cancer (n 33) from each method. No significant differences in either detection rate or calcification were seen between the two images. On the other hand, the ability to recognize tumor images (n 66) was as follows; CR superior to non-screen radiography in 53 lesions (80.3%), equal in eight lesions (12.1%) and inferior in five lesions (7.6%). For the calcification images (n 18), CR was superior to non-screen radiography in all 18 lesions. Obviously, CR gives better results than non-screen radiography. Furthermore, an adequate image can be obtained using CR even although the X-ray dosage is only a twentieth of that required for non-screen radiography. It can therefore be applied not only to mass surveys for breast cancer but also to routine clinical diagnoses. (author)

Constancy tests radiography X-ray devices with CR system

International Nuclear Information System (INIS)

Durdikova, M.; Zakova, M.

2005-01-01

The paper presents the changes in QAP (Quality Assurance Program) as consequence of digitalisation of medical facilities. Digitalisation brings many advantages - more comfort for personal use, images are easy achievable and transferable to workstation, fine quality images by postprocessing are easily achievable. But it must be taken into account that due to simplicity of image make it is sometimes taken more images then necessary .There are two possible ways of digitalisation in radiography: to exchange conventional developer machine by Computer Radiography (CR), that means to use CR reader and cassette with phosphor plate - un-direct digitalisation or to use special radiography X-ray devices with flat-panel detector -direct radiography. (authors)

Non-destructive evaluation utilizing imaging plates for field radiography applications

International Nuclear Information System (INIS)

White, Brian S.

2016-01-01

The oil and gas industry has utilized film radiography for the evaluation of pipeline welds for many years. The world has evolved, and today people are easily sharing digital images as part of the information revolution. Computed radiography is ready to replace film radiography for portable outdoor use applications. Computed radiography technology adoption has been contingent upon achieving acceptable image quality and getting enough imaging plate use cycles to be profitable. Image quality is dependent upon shot conditions, imaging plate type, reader settings, and scatter control. Likewise, the number of achievable use cycles is dependent upon the imaging plate design for durability and the user's operating environment. This presentation reviews the basic principles of storage phosphor imaging plates. Usage criteria and guidelines for optimum image quality and maximized overall use cycles will be discussed for various imaging plate types. A comparison of film and computed radiography imaging plate technology will be presented.

Application of computed radiography to ERCP

International Nuclear Information System (INIS)

Lee, Shigeki; Mochizuki, Fukuji; Fujita, Naotaka; Itoh, Shoichiro; Ikeda, Takashi; Toyohara, Tokiaki; Matsumoto, Kyoichi

1984-01-01

Computed radiography technic was applied to ERCP. Fuji Computed Radiography System was used. The pancreatogram obtained by this method was compared with that of conventional screen-film radiograph. The much finer changes of the pancreatogram can be delineated by the new method. The diagnostic ability of ERCP is thus enhanced by the introduction of FCR. (author)

Phosphor plate mammography: contrast studies and clinical experience

International Nuclear Information System (INIS)

Chang, C.H.J.; Martin, N.L.; Templeton, A.W.; Cook, L.T.; Harrison, L.A.; McFadden, M.A.; Dwyer, S.J. III; Spicer, J.; Crystal, J.M.

1992-01-01

Mammography and accurate microcalcification detection require very good spatial resolution. We have compared the diagnostic capabilities of reduced-exposure, third-generation, 5 cycles/mm computed radiography (CR) phosphor plates with conventional screen-film in 67 patients. No difference in diagnostic accuracy was detected. The digital characteristics of storage phosphor plates erabled us to study the relationship between contrast and spatial resolution. We developed a computer program to identify a single 100 μm pixel in a digital image and assign various gray levels to that pixel. Using this model, we determined that, for our 5 cycles/mm CR system, the imaged contrast of a 100 μm object was 62% of the original contrast. Current 5 cycles/mm phosphor plate systems cannot adequately detect microcalcifications that approximate 100 μm or smaller unless a magnification technique is used. (orig.)

Computed Radiography Exposure Indices in Mammography | Koen ...

African Journals Online (AJOL)

Computed Radiography Exposure Indices in Mammography. L Koen, C Herbst, W Rae. Abstract. Background. Studies indicate that computed radiography (CR) can lead to increased radiation dose to patients. It is therefore important to relate the exposure indicators provided by CR manufacturers to the radiation dose ...

Radiological protection procedures for industrial applications of computed radiography

International Nuclear Information System (INIS)

Aquino, Josilto Oliveira de

2009-03-01

Due to its very particular characteristics, industrial radiography is responsible for roughly half of the relevant accidents in nuclear industry, in developed as well as in developing countries, according to the International Atomic Energy Agency (IAEA). Thus, safety and radiological protection in industrial gamma radiography have been receiving especial treatment by regulatory authorities of most Member States. The main objective of the present work was to evaluate, from the radioprotection point of view, the main advantages of computed radiography (CR) for filmless industrial radiography. In order to accomplish this, both techniques, i.e. conventional and filmless computed radiography were evaluated and compared through practical studies. After the studies performed at the present work it was concluded that computed radiography significantly reduces the inherent doses, reflecting in smaller restricted areas and costs, with consequent improvement in radiological protection and safety. (author)

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

Science.gov (United States)

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

Phantom gastric mucosa for evaluating computed radiography in double-contrast upper gastrointestinal examinations

International Nuclear Information System (INIS)

Murakami, M.; Watanabe, H.; Nakata, H.

1996-01-01

To test the clinical usefulness of computed radiography (CR) with a storage phosphor plate in upper gastrointestinal radiographic examinations, a newly devised phantom gastric mucosa was used. Simulated small elevated and depressed lesions were created on a phantom gastric mucosa made from a styrofoam 'plate'. Twenty-four sets of each CR and screen-film radiographs (SR) were obtained using phototimed exposures. Receiver operating characteristic (ROC) study and visual ranking using these images were performed. There was no significant difference between the ROC curves of CR and SR. By visual ranking, CR was equal to or better than SR in most cases. In no case was SR definitely superior to CR. CR can be safely applied in upper gastrointestinal roentgenologic examinations. (orig.)

Storage phosphor radiography of wrist fractures: a subjective comparison of image quality at varying exposure levels

Energy Technology Data Exchange (ETDEWEB)

Peer, Regina; Giacomuzzi, Salvatore M.; Bodner, Gerd; Jaschke, Werner; Peer, Siegfried [Innsbruck Univ. (Austria). Inst. fuer Radiologie; Lanser, Anton [Academy of Radiology Technicians, Innsbruck (Austria); Pechlaner, Sigurd [Department of Traumatology, University Hospital, Innsbruck (Austria); Kuenzel, Karl Heinz; Gaber, O. [Department of Anatomy and Histology, University Hospital, Innsbruck (Austria)

2002-06-01

Image quality of storage phosphor radiographs acquired at different exposure levels was compared to define the minimal radiation dose needed to achieve images which allow for reliable detection of wrist fractures. In a study on 33 fractured anatomical wrist specimens image quality of storage phosphor radiographs was assessed on a diagnostic PACS workstation by three observers. Images were acquired at exposure levels corresponding to a speed classes 100, 200, 400 and 800. Cortical bone surface, trabecular bone, soft tissues and fracture delineation were judged on a subjective basis. Image quality was rated according to a standard protocol and statistical evaluation was performed based on an analysis of variance (ANOVA). Images at a dose reduction of 37% were rated sufficient quality without loss in diagnostic accuracy. Sufficient trabecular and cortical bone presentation was still achieved at a dose reduction of 62%. The latter images, however, were considered unacceptable for fracture detection. To achieve high-quality storage phosphor radiographs, which allow for a reliable evaluation of wrist fractures, a minimum exposure dose equivalent to a speed class of 200 is needed. For general-purpose skeletal radiography, however, a dose reduction of up to 62% can be achieved. A choice of exposure settings according to the clinical situation (ALARA principle) is recommended to achieve possible dose reductions. (orig.)

Performance evaluation of a 'dual-side read' dedicated mammography computed radiography system

International Nuclear Information System (INIS)

Fetterly, Kenneth A.; Schueler, Beth A.

2003-01-01

The image quality of a dedicated mammography computed radiography (CR) system was characterized. A unique feature of this system is that it collects image signals from both sides of the storage phosphor. Measurements of the modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) were made. This work included improvements in our measurement methods to specifically account for the detrimental effects of system glare on the MTF and to accurately characterize the low-frequency NPS components. Image quality measurements were performed using a 25 kVp beam filtered with 2 mm Al and an exposure range of 1 to 100 mR (87 to 870 μGy). The DQE was found to decrease with increasing exposure due to an increased contribution of storage phosphor structure noise. The DQE of this system was compared to similar measurements made using a standard CR system. The dual-side read system demonstrated superior DQE compared to the standard system. The decrease in DQE with increasing exposure was more severe for the standard system than the dual-side read system. This finding suggests that the CR system noise was reduced for the dual-side read system compared to the standard system

Corrosion Surveillance In Pipe By Computed Radiography

International Nuclear Information System (INIS)

Nguyen The Man; Dao Duy Dung; Dang Thu Hong; Le Duc Thinh; Ha Hong Thu; Nguyen Trong Nghia

2014-01-01

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

Digital radiography: a survey of pediatric dentists.

Science.gov (United States)

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.

Comparison of cone - beam computed tomography and intraoral radiography in detection of recurrent caries under composite restorations

Energy Technology Data Exchange (ETDEWEB)

Kasraei, Shahin; Shokri, Abbas; Poorolajal, Jalal; Rahmani, Hamid, E-mail: Dr.a.shokri@gmail.com [Hamadan University of Medical Sciences Hamadan (Iran, Islamic Republic of); Khajeh, Samira [Kurdistan University of Medical Sciences, Sanandaj (Iran, Islamic Republic of)

2017-01-15

Secondary caries is the most common cause of dental restoration failures. This study aimed to compare the diagnostic accuracy of conventional and digital intraoral radiography and cone beam computed tomography (CBCT) for detection of recurrent caries around composite restorations mesio-occluso-distal (MOD) cavities were prepared using bur on 45 extracted sound human molar teeth. The teeth were divided into 3 groups. In the control group, cavities were restored with composite resin after etching and bonding (n=15). In Group 2, 500-μm thick wax was placed over the buccal, lingual and gingival walls and the cavities were restored with composite resin. Group 3 specimens were subjected to pH cycling and artificial caries were created on the buccal, lingual and gingival walls. The cavities were restored with composite. Conventional and digital photo-stimulable phosphor (PSP; Optime) radiographs and two CBCTs images (NewTom 3G and Cranex 3D) were obtained from them. Presence or absence of caries in the cavity walls was assessed on these images. Data were analyzed using Kappa statistic. The diagnostic accuracy of CBCT was significantly higher than that of digital and conventional intraoral radiography (p<0.05). The accuracy was 0.83, 0.78, 0.55 and 0.49 for CBCT Cranex 3D, CBCT NewTom 3G, conventional and digital intraoral radiography, respectively. CBCT has a higher diagnostic accuracy than digital and conventional intraoral radiography for detection of secondary caries around composite restorations. (author)

Comparison of cone - beam computed tomography and intraoral radiography in detection of recurrent caries under composite restorations

International Nuclear Information System (INIS)

Kasraei, Shahin; Shokri, Abbas; Poorolajal, Jalal; Rahmani, Hamid; Khajeh, Samira

2017-01-01

Secondary caries is the most common cause of dental restoration failures. This study aimed to compare the diagnostic accuracy of conventional and digital intraoral radiography and cone beam computed tomography (CBCT) for detection of recurrent caries around composite restorations mesio-occluso-distal (MOD) cavities were prepared using bur on 45 extracted sound human molar teeth. The teeth were divided into 3 groups. In the control group, cavities were restored with composite resin after etching and bonding (n=15). In Group 2, 500-μm thick wax was placed over the buccal, lingual and gingival walls and the cavities were restored with composite resin. Group 3 specimens were subjected to pH cycling and artificial caries were created on the buccal, lingual and gingival walls. The cavities were restored with composite. Conventional and digital photo-stimulable phosphor (PSP; Optime) radiographs and two CBCTs images (NewTom 3G and Cranex 3D) were obtained from them. Presence or absence of caries in the cavity walls was assessed on these images. Data were analyzed using Kappa statistic. The diagnostic accuracy of CBCT was significantly higher than that of digital and conventional intraoral radiography (p<0.05). The accuracy was 0.83, 0.78, 0.55 and 0.49 for CBCT Cranex 3D, CBCT NewTom 3G, conventional and digital intraoral radiography, respectively. CBCT has a higher diagnostic accuracy than digital and conventional intraoral radiography for detection of secondary caries around composite restorations. (author)

Computed Radiography: An Innovative Inspection Technique

International Nuclear Information System (INIS)

Klein, William A.; Councill, Donald L.

2002-01-01

Florida Power and Light Company's (FPL) Nuclear Division combined two diverse technologies to create an innovative inspection technique, Computed Radiography, that improves personnel safety and unit reliability while reducing inspection costs. This technique was pioneered in the medical field and applied in the Nuclear Division initially to detect piping degradation due to flow-accelerated corrosion. Component degradation can be detected by this additional technique. This approach permits FPL to reduce inspection costs, perform on line examinations (no generation curtailment), and to maintain or improve both personnel safety and unit reliability. Computed Radiography is a very versatile tool capable of other uses: - improving the external corrosion program by permitting inspections underneath insulation, and - diagnosing system and component problems such as valve positions, without the need to shutdown or disassemble the component. (authors)

Effect of grinding on photostimuable phosphors for x-ray screens

International Nuclear Information System (INIS)

Rao, R.B.

1988-01-01

Luminescence efficiency of a phosphor can be improved by minimizing the energy losses during excitation. The loss of excitation energy in the case of powdered samples is mainly due to scattering of incident radiation by the particles of phosphor. Thus, while considering the industrial applications of polycrystalline phosphors in lamps, screens, paints, etc., the effect of particle size on the light output has to be specially studied. It is very well established that the radiographic imaging with photostimuable (PS) phosphors has many advantages over conventional photographic film screens. In the new type of computer radiography, PS phosphors are to be used as memory materials for temporary storage of the x-ray image. Eu(2+) doped barium fluorohalide phosphors are most suitable for this purpose. The spatial resolution from the image plate can be improved to a certain extent with phosphors comprising fine particles. The fineness of the particles can be achieved by various means such as grinding, fast cooling after firing or incorporation of some flux materials during the firing processes. But the efficiency of the phosphor deteriorates with grinding. Fast cooling is a complicated process in the case of Eu(2+) doped phosphors. Incorporation of flux materials may change the characteristics of phosphor materials. In the present investigation, effect of grinding (ball milling) on particle size distribution, shape of the particles and luminescent properties of BaFCl phosphors have been studied

Phosphor Scanner For Imaging X-Ray Diffraction

Science.gov (United States)

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

1992-01-01

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

Performance characteristics of a Kodak computed radiography system.

Science.gov (United States)

Bradford, C D; Peppler, W W; Dobbins, J T

1999-01-01

The performance characteristics of a photostimulable phosphor based computed radiographic (CR) system were studied. The modulation transfer function (MTF), noise power spectra (NPS), and detective quantum efficiency (DQE) of the Kodak Digital Science computed radiography (CR) system (Eastman Kodak Co.-model 400) were measured and compared to previously published results of a Fuji based CR system (Philips Medical Systems-PCR model 7000). To maximize comparability, the same measurement techniques and analysis methods were used. The DQE at four exposure levels (30, 3, 0.3, 0.03 mR) and two plate types (standard and high resolution) were calculated from the NPS and MTF measurements. The NPS was determined from two-dimensional Fourier analysis of uniformly exposed plates. The presampling MTF was determined from the Fourier transform (FT) of the system's finely sampled line spread function (LSF) as produced by a narrow slit. A comparison of the slit type ("beveled edge" versus "straight edge") and its effect on the resulting MTF measurements was also performed. The results show that both systems are comparable in resolution performance. The noise power studies indicated a higher level of noise for the Kodak images (approximately 20% at the low exposure levels and 40%-70% at higher exposure levels). Within the clinically relevant exposure range (0.3-3 mR), the resulting DQE for the Kodak plates ranged between 20%-50% lower than for the corresponding Fuji plates. Measurements of the presampling MTF with the two slit types have shown that a correction factor can be applied to compensate for transmission through the relief edges.

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

Science.gov (United States)

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

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

International Nuclear Information System (INIS)

Gruber, Michael; Uffmann, Martin; Weber, Michael; Balassy, Csilla; Schaefer-Prokop, Cornelia; Prokop, Mathias

2006-01-01

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

Computational radiology in skeletal radiography

International Nuclear Information System (INIS)

Peloschek, Ph.; Nemec, S.; Widhalm, P.; Donner, R.; Birngruber, E.; Thodberg, H.H.; Kainberger, F.; Langs, G.

2009-01-01

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

Digital radiography of the chest

International Nuclear Information System (INIS)

Sakurai, Kenji; Hachiya, Junichi; Korenaga, Tateo; Nitatori, Toshiaki; Miyasaka, Yasuo; Furuya, Yoshiro

1984-01-01

Initial clinical experience in digital chest radiography utilizing photostimulable phosphor and scanning laser stimulated luminescence was reported. Image quality of conventional film/screen radiography and digital radiography was compared in 30 normal cases. Reflecting wide dynamic range of the system, improved image quality was confirmed in all 30 cases, particularly in visibility of various mediastinal structures and pulmonary vessels. High sensor sensitivity of the system enabled digital radiography to reduce radiation dose requirement significantly. Diagnostically acceptable chest images were obtained with approximately 1/5 of routine dose for conventional radiography without significant image quality degradation. Some artifact created by digital processing were mostly overcome by a routine use of simultaneous display of two different types of image processing and therefore was not an actual drawback from diagnostic standpoint. Further technical advancement of the system to be seen for digital storage, retrieval and tranceference of images. (author)

Assessment of weld thickness loss in offshore pipelines using computed radiography and computational modeling

International Nuclear Information System (INIS)

Correa, S.C.A.; Souza, E.M.; Oliveira, D.F.; Silva, A.X.; Lopes, R.T.; Marinho, C.; Camerini, C.S.

2009-01-01

In order to guarantee the structural integrity of oil plants it is crucial to monitor the amount of weld thickness loss in offshore pipelines. However, in spite of its relevance, this parameter is very difficult to determine, due to both the large diameter of most pipes and the complexity of the multi-variable system involved. In this study, a computational modeling based on Monte Carlo MCNPX code is combined with computed radiography to estimate the weld thickness loss in large-diameter offshore pipelines. Results show that computational modeling is a powerful tool to estimate intensity variations in radiographic images generated by weld thickness variations, and it can be combined with computed radiography to assess weld thickness loss in offshore and subsea pipelines.

Efficacy of daily bedside chest radiography as visualized by digital luminescence radiography

International Nuclear Information System (INIS)

Kirchner, J.; Stueckle, C.A.; Schilling, E.M.; Peters, J.

2001-01-01

To determine the diagnostic impact of daily bedside chest radiography in comparison with digital luminescence technique (DLR; storage phosphor radiography) and conventional film screen radiography, a prospective randomized study was completed in 210 mechanically ventilated patients with a total of 420 analysed radiographs. The patients were allocated to two groups: 150 patients underwent DLR, and 60 patients underwent conventional film screen radiography. Radiological analysis was performed consensually and therapeutic efficacy was assessed by the clinicians. There was no statistical significant difference between the frequency of abnormal findings seen on DLR and conventional film screen radiography. In total, 448 abnormal findings were present in 249 of 300 DLR and 97 of 120 conventional film screen radiographs. The most common findings were signs of overhydration (41 %), pleural effusion (31%), partial collapse of the lung (11%) and pneumothorax (2%). One hundred and twenty-three of 448 (27%) of these abnormal findings were thought to have a considerable impact on patient management. The high rate of abnormal findings with significant impact on patient management suggests that the use of daily bedside chest radiography may be reasonable. Copyright (2001) Blackwell Science Pty Ltd

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

NARCIS (Netherlands)

de Boo, D. W.; Weber, M.; Deurloo, E. E.; Streekstra, G. J.; Freling, N. J.; Dongelmans, D. A.; Schaefer-Prokop, C. M.

2011-01-01

To asses the image quality and potential for dose reduction of mobile direct detector (DR) chest radiography as compared with computed radiography (CR) for intensive care unit (ICU) chest radiographs (CXR). Three groups of age-, weight- and disease-matched ICU patients (n=114 patients; 50 CXR per

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

Science.gov (United States)

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.

Computed Tomography and Computed Radiography of late Bronze Age Cremation Urns from Denmark

DEFF Research Database (Denmark)

Harvig, Lise Lock; Lynnerup, Niels; Amsgaard Ebsen, Jannie

2012-01-01

To improve methods used to study prehistoric cremation rituals, cremation urns from the Danish late Bronze Age were examined using Computed Tomography and Computed Radiography (Digital X-ray). During microexcavation, the digital images were used as registration tool. Our results suggest...

Diagnostic accuracy of phosphor plate systems and conventional radiography in the detection of simulated internal root resorption.

Science.gov (United States)

Vasconcelos, Karla de Faria; Rovaris, Karla; Nascimento, Eduarda Helena Leandro; Oliveira, Matheus Lima; Távora, Débora de Melo; Bóscolo, Frab Norberto

2017-11-01

To evaluate the performance of conventional radiography and photostimulable phosphor (PSP) plate in the detection of simulated internal root resorption (IRR) lesions in early stages. Twenty single-rooted teeth were X-rayed before and after having a simulated IRR early lesion. Three imaging systems were used: Kodak InSight dental film and two PSPs digital systems, Digora Optime and VistaScan. The digital images were displayed on a 20.1″ LCD monitor using the native software of each system, and the conventional radiographs were evaluated on a masked light box. Two radiologists were asked to indicate the presence or absence of IRR and, after two weeks, all images were re-evaluated. Cohen's kappa coefficient was calculated to assess intra- and interobserver agreement. The three imaging systems were compared using the Kruskal-Wallis test. For interexaminer agreement, overall kappa values were 0.70, 0.65 and 0.70 for conventional film, Digora Optima and VistaScan, respectively. Both the conventional and digital radiography presented low sensitivity, specificity, accuracy, positive and negative predictive values with no significant difference between imaging systems (p = .0725). The performance of conventional and PSP was similar in the detection of simulated IRR lesions in early stages with low accuracy.

The clinical application of computed radiography in bedside photography of newborn

International Nuclear Information System (INIS)

Peng Sen; Guo Tianchang

2005-01-01

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

Dose optimisation in computed radiography

International Nuclear Information System (INIS)

Schreiner-Karoussou, A.

2005-01-01

After the installation of computed radiography (CR) systems in three hospitals in Luxembourg a patient dose survey was carried out for three radiographic examinations, thorax, pelvis and lumbar spine. It was found that the patient doses had changed in comparison with the patient doses measured for conventional radiography in the same three hospitals. A close collaboration between the manufacturers of the X-ray installations, the CR imaging systems and the medical physicists led to the discovery that the speed class with which each radiographic examination was to be performed, had been ignored, during installation of the digital imaging systems. A number of procedures were carried out in order to calibrate and program the X-ray installations in conjunction with the CR systems. Following this optimisation procedure, a new patient dose survey was carried out for the three radiographic examinations. It was found that patient doses for the three hospitals were reduced. (authors)

Physical image quality of computed radiography in mammography system

International Nuclear Information System (INIS)

Norriza Mohd Isa; Muhammad Jamal Isa; Wan Muhamad Saridan Wan Hassan; Fatimah Othman

2013-01-01

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

Image quality and dose management in digital radiography: A new paradigm for optimisation

International Nuclear Information System (INIS)

Busch, H. P.; Faulkner, K.

2005-01-01

The advent of digital imaging in radiology, combined with the explosive growth of technology, has dramatically improved imaging techniques. This has led to the expansion of diagnostic capabilities, both in terms of the number of procedures and their scope. Throughout the world, film/ screen radiography systems are being rapidly replaced with digital systems. Many progressive medical institutions have acquired, or are considering the purchase of computed radiography systems with storage phosphor plates or direct digital radiography systems with flat panel detectors. However, unknown to some users, these devices offer a new paradigm of opportunity and challenges. Images can be obtained at a lower dose owing to the higher detective quantum efficiency (DQE). These fundamental differences in comparison to conventional film/screens necessitate the development of new strategies for dose and quality optimisations. A set of referral criteria based upon three dose levels is proposed. (authors)

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

Science.gov (United States)

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

2016-01-01

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. 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. Pooled sensitivity was higher in RED-MDCT with 0.89 and RED-MDCT with 0.81 compared to radiography with 0.54 (P = radiography (P 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.

Improvements in phosphors

International Nuclear Information System (INIS)

Rabatin, J.G.

1981-01-01

For X-ray image converter applications, especially when used in medical radiography, it is desirable to improve the speed and brightness of response for conversion of X-rays in phosphors. The rare earth oxyhalide phosphors coactivated with a combination of rare earth activators described in this patent are capable of exhibiting low afterglow with high ultraviolet emission. They have the general formula Lnsub(1-y-w)OX:Tbsub(y)Tmsub(w) where Ln is lanthanum or gadolinium, X is chlorine and/or bromine, y is from 0.0005 to 0.010 moles per mole and w is from 0.00005 to 0.005 moles per mole of the Lnsub(1-y-w)OX host. The method of preparation and characteristics of speed, afterglow and UV emission are described. (U.K.)

Characteristics of high-energy X-rays using computed radiography systems

International Nuclear Information System (INIS)

Matsumoto, Mitsuhiro; Mori, Yoshinobu

1993-01-01

A computed radiography (CR) with storage phosphor technology has advanced remarkably. Its application has been also discussed regarding the field of radiotherapy and studies have been made to shift from the film/screen system to the portal film using the CR system. The authors started to research CR portal imaging with high energy X-ray (10MV) on a regular scale in 1989. This paper deals with characteristics of high energy X-rays using the CR system. The digital characteristic curve corresponded with calculated value for dynamic range (L-value). The monitor unit (MU) counts at pixel (digital) value saturation point were L-value 0.5:28 MU, L-value 1.0:50 MU, L-value 2.0:167 MU, L-value 3.0:450 MU, L-value 4.0:1614 MU. The image contrast with the Mix-Dp phantom was L-value 0.5: about a 300 pixel value and L-value 4.0: about a 30 pixel value by a phantom 10 to 18 cm in thickness. Optimum L-value was 0.5, and tone-scale was the straight type of CR portal imaging using the graphy count mode. Optimum L-value was 4.0, and tone-scale was a rectangular wave type of CR portal imaging using therapeutic doses, and those were also described by the histogram analysis. (author)

Digital chest radiography: flat-panel detectors or conventional radiographs

International Nuclear Information System (INIS)

Schaefer-Prokop, C.; Uffmann, M.; Sailer, J.; Kabalan, N.; Herold, C.; Prokop, M.

2003-01-01

Flat panel detectors are characterized by improved handling and increased dose efficiency. This allows for increasing of work flow efficiency and for reducing the exposure dose by about 50% compared to current systems with a sensitivity of 400. Whether the increased dose efficiency should be used to reduce acquisition dose or to increase image quality in the chest, will be shown by further clinical experience and will be also determined by the subjective preference of the radiologists. The decreased level of image noise opens new perspectives for image processing that way that elaborated multifrequency processing allows for optimizing the display of very small and low contrast structures that was so far limited by overlying image noise. Specialized applications of dual energy subtraction and temporal subtraction will also profit by the new detector technology and will be further driven forward in context with applications such as computed assisted diagnosis even though this is currently not yet broadly applied. Storage phosphor radiography still represents an important alternative technique based on its larger flexibility with respect to equipment configuration, its broader application options in intensive care and emergency radiology and due to economic reasons. These facts are further underlined by the fact that image quality also in storage phosphor radiography could be constantly increased by improving detector technology and image processing and consequently has a high standard. (orig.) [de

Digital radiography of the chest: state of the art

International Nuclear Information System (INIS)

Souto, M.; Malagari, K.S.; Tucker, D.; Tahoces, P.G.; Correa, J.; Benakis, V.S.; Roussos, C.; Strigaris, K.A.; Vidal, J.J.; Barnes, G.T.; Fraser, R.G.

1994-01-01

Digital image acquisition possesses a number of advantages over conventional systems in radiographic examination of the chest, the most important of which is its greater dynamic range. In addition, once digital images are acquired, they can be processed by computer in ways that cannot be rivalled by conventional analog techniques. Finally, digital images can be stored, retrieved and transmitted to local or remote sites. Here the status of the different digital systems employed in chest radiology and commonly used image processing techniques are reviewed. Also discussed are the current clinical applications of integrating digital chest radiography with a picture archiving and communication system (PACS) along with the difficulties typically encountered. Studies with a variety of digital techniques have been carried out on several fronts. Computed radiography based on photostimulable phosphor (CR) has replaced screen-film imaging in certain applications (i.e. bedside imaging). However, CR has limitations, namely its poor X-ray utilisation efficiency at high X-ray tube voltages and sensitivity to scatter; therefore, it is not ideal for all applications. Recently, a dedicated digital chest unit with excellent X-ray utilisation efficiency at high X-ray tube potentials has been introduced. On the basis of the state-of-the-art capabilities and research during the past decade, recommendations are made regarding the most desirable equipment specifications for dedicated and bedside digital chest radiography. (orig.)

A preliminary investigation of the imaging performance of photostimulable phosphor computed radiography using a new design of mammographic quality control test object

International Nuclear Information System (INIS)

Cowen, A.R.; Brettle, D.S.; Coleman, N.J.; Parkin, G.J.S.

1992-01-01

Leeds Test Object TOR[MAM] has been designed to supplement the current FAXIL mammography test object TOR[MAX]. It contains a range of details that have a more natural radiographic appearance and has been designed as a test that more closely approximates the image quality achieved in clinical mammography. Physical aspects of the design and implementation of TOR[MAM] are presented. The TOR[MAM] has been used in a preliminary physical evaluation of the comparative image qualities produced by conventional (screen-film) and phostostimulable phosphor computed mammography and the results are discussed. TOR[MAX] results are also presented. The influence of digital image processing (enhancement) on the image quality of computed mammograms is also considered. The results presented indicate the sensitivity of TOR[MAM]. (author)

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

International Nuclear Information System (INIS)

Nakazeko, Kazuma; Araki, Misao; Kajiwara, Hironori; Watanabe, Hiroyuki; Kuwayama, Jun; Karube, Shuhei; Hashimoto, Takeyuki; Shinohara, Hiroyuki

2012-01-01

We present a computer assisted learning (CAL) program to simulate head radiography. The program provides cone beam projections of a target volume, simulating three-dimensional computed tomography (CT) of a head phantom. The generated image is 512 x 512 x 512 pixels with each pixel 0.6 mm on a side. The imaging geometry, such as X-ray tube orientation and phantom orientation, can be varied. The graphical user interface (GUI) of the CAL program allows the study of the effects of varying the imaging geometry; each simulated projection image is shown quickly in an adjoining window. Simulated images with an assigned geometry were compared with the image obtained using the standard geometry in clinical use. The accuracy of the simulated image was verified through comparison with the image acquired using radiography of the head phantom, subsequently processed with a computed radiography system (CR image). Based on correlation coefficient analysis and visual assessment, it was concluded that the CAL program can satisfactorily simulate the CR image. Therefore, it should be useful for the training of head radiography. (author)

Studies on the Fuji computed radiography depended on the panoramic radiography

International Nuclear Information System (INIS)

Nakamura, Satoshi; Shiota, Satoru; Takazawa, Kazuyoshi; Yoshida, Toru; Takagi, Yoshiko; Funamoto, Choichiro

1986-01-01

The Fuji Computed Radiography (FCR) developed recently involves the following procedures; photography in the same way as the hitherto radiography, printing auto imaging plate of photostimulable phospher, conversion to electric signals, and recording reproduced images by computerization. Highly valuable images for diagnoses in the medical field have already been obtained by the FCR. Then, we attempted to study FCR images panoramically radiographed for jaw lesions in the field of oral surgery. Method for study: As the samples to be studied, the selected subjects were cases of periodontal diseases, fracture of the jaw, odontogenic cyst and tumor, etc. In the present study the FCR images of panoramic radiography were compared with hitherto panoramic flat radiograms. Result of study: Although the images of the FCR vary depending on the methods of treatment, that is, on how gradient processing and spatial frequency enhancement are, the method of purpose-fitting treatment provided diagnostically significant images for grasping bone lesions. The images obtained from this FCR permitted us to grasp more distinctly condition of alveolar bone resorption in periodontal diseases, running of minute fracture lines in fracture of the jaw, and characteristic images of bone resorption in odontogenic cysts and tumor, etc. Thus the images of the FCR are highly useful in diagnosing bone lesions, but granularity of the images themselves have still been questioned, and additionally the images vary depending on the methods of gradient processing and spatial frequency enhancement. Therefore further repeat studies are probably needed for these questions. (author)

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

International Nuclear Information System (INIS)

Park, R.D.; Beck, E.R.; LeCouteur, R.A.

1992-01-01

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

Improvements relating to radiography

International Nuclear Information System (INIS)

Bollen, R.H.; Vandenabeele, H.

1977-01-01

An improved combination of photosensitive materials suitable for use in radiography is described, with particular reference to a combination for an X-ray intensifying screen of the fluorescent type and a silver halide recorder. The intensifying material comprises a phosphor consisting wholly or mainly of a rare earth metal activated lanthanum oxyhalide, having more than half its spectral energy emission > 410 nm wavelength, more than half its visible light spectral energy emission in the range 400 to 500 nm, and its maximum energy emission peak in the range 400 to 450 nm. The phosphor should have a coverage of at least 200 to 800 g of the oxyhalide per sq. m. The screen material also contains a dye or pigment that absorbs light within the emission spectrum of the phosphor. The photosensitive recording material incorporates at least one silver halide emulsion layer. The combination should give a screen intensification factor of at least 20 to 40 kV. (U.K.)

Miniature, mobile X-ray computed radiography system

Science.gov (United States)

Watson, Scott A; Rose, Evan A

2017-03-07

A miniature, portable x-ray system may be configured to scan images stored on a phosphor. A flash circuit may be configured to project red light onto a phosphor and receive blue light from the phosphor. A digital monochrome camera may be configured to receive the blue light to capture an article near the phosphor.

Need for New Optimisation Strategies in CR and Direct Digital Radiography

International Nuclear Information System (INIS)

Busch, H.P.

2000-01-01

Digital imaging techniques such as Digital Image Intensifier Radiography and Digital Storage Phosphor (Selenium) Radiography are replacing conventional film-screen radiography more and more. The aim of this development is the extension of diagnostic capabilities and the reduction of side effects such as radiation dose. Conventional film-screen radiography and digital radiography are very different ways of imaging. For digital radiography specific post-processing is the link between imaging conditions and film documentation. Optimisation of the images includes new possibilities of post-processing and a broad range for variation of the dose. Especially in fluoroscopy, dose can be reduced significantly by new technical features like pulsed fluoroscopy. For digital radiography the European guidelines on quality criteria have to be applied to projection radiography, digital subtraction radiography and to fluoroscopy. Further work should lead to a definition of reference values for the dose and the image quality. This has to be done first for single exposures and fluoroscopic mode and secondly for diagnostic and interventional procedures. (author)

Computed simulation of radiographies of pipes - validation of techniques for wall thickness measurements

International Nuclear Information System (INIS)

Bellon, C.; Tillack, G.R.; Nockemann, C.; Wenzel, L.

1995-01-01

A macroscopic model of radiographic NDE methods and applications is given. A computer-aided approach for determination of wall thickness from radiographs is presented, guaranteeing high accuracy and reproducibility of wall thickness determination by means of projection radiography. The algorithm was applied to computed simulations of radiographies. The simulation thus offers an effective means for testing such automated wall thickness determination as a function of imaging conditions, pipe geometries, coatings, and media tracking, and likewise is a tool for validation and optimization of the method. (orig.) [de

Radiological protection procedures for industrial applications of computed radiography; Procedimentos de protecao radiologica em aplicacoes industriais da radiografia computadorizada

Energy Technology Data Exchange (ETDEWEB)

Aquino, Josilto Oliveira de

2009-03-15

Due to its very particular characteristics, industrial radiography is responsible for roughly half of the relevant accidents in nuclear industry, in developed as well as in developing countries, according to the International Atomic Energy Agency (IAEA). Thus, safety and radiological protection in industrial gamma radiography have been receiving especial treatment by regulatory authorities of most Member States. The main objective of the present work was to evaluate, from the radioprotection point of view, the main advantages of computed radiography (CR) for filmless industrial radiography. In order to accomplish this, both techniques, i.e. conventional and filmless computed radiography were evaluated and compared through practical studies. After the studies performed at the present work it was concluded that computed radiography significantly reduces the inherent doses, reflecting in smaller restricted areas and costs, with consequent improvement in radiological protection and safety. (author)

Dual energy radiography using active detector technology

International Nuclear Information System (INIS)

Seibert, J.A.; Poage, T.F.; Alvarez, R.E.

1996-01-01

A new technology has been implemented using an open-quotes active-detectorclose quotes comprised of two computed radiography (CR) imaging plates in a sandwich geometry for dual-energy radiography. This detector allows excellent energy separation, short exposure time, and high signal to noise ratio (SNR) for clinically robust open-quotes bone-onlyclose quotes and open-quotes soft-tissue onlyclose quotes images with minimum patient motion. Energy separation is achieved by two separate exposures at widely different kVp's: the high energy (120 kVp + 1.5 mm Cu filter) exposure is initiated first, followed by a short burst of intense light to erase the latent image on the front plate, and then a 50 kVp (low energy) exposure. A personal computer interfaced to the x-ray generator, filter wheel, and active detector system orchestrates the acquisition sequence within a time period of 150 msec. The front and back plates are processed using a CR readout algorithm with fixed speed and wide dynamic range. open-quotes Bone-onlyclose quotes and open-quotes soft-tissue onlyclose quotes images are calculated by geometric alignment of the two images and application of dual energy decomposition algorithms on a pixel by pixel basis. Resultant images of a calibration phantom demonstrate an increase of SNR 2 / dose by ∼73 times when compared to a single exposure open-quotes passive-detectorclose quotes comprised of CR imaging plates, and an ∼8 fold increase compared to a screen-film dual-energy cassette comprised of different phosphor compounds. In conclusion, dual energy imaging with open-quotes active detectorclose quotes technology is clinically feasible and can provide substantial improvements over conventional methods for dual-energy radiography

Phantom examination for reduction of radiation dose using new needle screen storage phosphor radiography and add beam filter in digital thoracic radiography on adolescents and larger children

International Nuclear Information System (INIS)

Heyne, J.P.; Mentzel, H.J.; Neumann, R.; Lopatta, E.; Zimmermann, U.; Kaiser, W.A.

2008-01-01

Purpose: how much can the radiation dose be reduced in thoracic radiography on adolescents and larger children by using needle screen storage phosphor (NIP) radiography and add beam filtration? Materials and methods: a chest phantom with typical anatomical structures, pathological findings, added catheters, and simulated nodules, tumors, and calcifications was X-rayed digitally (DX-S, Agfa Healthcare) in posterior-anterior (p.a.) orientation with and without add beam filter. While keeping the voltage constant, the tube current time product was reduced gradually. In addition to LgM, the surface entrance dose (ED) and the dose area product (DAP) were measured by the Dosimax sensor and Kerma X-plus (both Wellhoefer). Five investigators evaluated the images for characteristics and critical features, pathological findings, and catheter recognizability. Results: the ED of the digital chest radiogram p.a. with 115 kV and 0.71 mAs was 27 μGy, the DAP 3.6 μGy x m 2 , the LgM value 1.56. This initial radiogram was able to be evaluated very well and conforms to the quality guidelines. The dose-reduced chest radiograms with the add beam filter Al 1.0 mm/Cu 0.1 mm were evaluated as sufficiently reduced to a dose of 63% of the initial dose, with the add beam filter Al 1.0 mm/Cu 0.2 mm reduced to 50% (0.52 mAs, DAP 1.82 μGy x m 2 , LgM 1.35). P.a. radiograms were able to be X-rayed on 115 kV with 0.52 mAs. (orig.)

Computed radiography simulation using the Monte Carlo code MCNPX

International Nuclear Information System (INIS)

Correa, S.C.A.; Souza, E.M.; Silva, A.X.; Lopes, R.T.

2009-01-01

Simulating x-ray images has been of great interest in recent years as it makes possible an analysis of how x-ray images are affected owing to relevant operating parameters. In this paper, a procedure for simulating computed radiographic images using the Monte Carlo code MCNPX is proposed. The sensitivity curve of the BaFBr image plate detector as well as the characteristic noise of a 16-bit computed radiography system were considered during the methodology's development. The results obtained confirm that the proposed procedure for simulating computed radiographic images is satisfactory, as it allows obtaining results comparable with experimental data. (author)

Computed radiography simulation using the Monte Carlo code MCNPX

Energy Technology Data Exchange (ETDEWEB)

Correa, S.C.A. [Programa de Engenharia Nuclear/COPPE, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Centro Universitario Estadual da Zona Oeste (CCMAT)/UEZO, Av. Manuel Caldeira de Alvarenga, 1203, Campo Grande, 23070-200, Rio de Janeiro, RJ (Brazil); Souza, E.M. [Programa de Engenharia Nuclear/COPPE, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Silva, A.X., E-mail: ademir@con.ufrj.b [PEN/COPPE-DNC/Poli CT, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Cassiano, D.H. [Instituto de Radioprotecao e Dosimetria/CNEN Av. Salvador Allende, s/n, Recreio, 22780-160, Rio de Janeiro, RJ (Brazil); Lopes, R.T. [Programa de Engenharia Nuclear/COPPE, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil)

2010-09-15

Simulating X-ray images has been of great interest in recent years as it makes possible an analysis of how X-ray images are affected owing to relevant operating parameters. In this paper, a procedure for simulating computed radiographic images using the Monte Carlo code MCNPX is proposed. The sensitivity curve of the BaFBr image plate detector as well as the characteristic noise of a 16-bit computed radiography system were considered during the methodology's development. The results obtained confirm that the proposed procedure for simulating computed radiographic images is satisfactory, as it allows obtaining results comparable with experimental data.

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

International Nuclear Information System (INIS)

Peters, Sinead E.; Brennan, Patrick C.

2002-01-01

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. (orig.)

Computed radiography systems performance evaluation

International Nuclear Information System (INIS)

Xavier, Clarice C.; Nersissian, Denise Y.; Furquim, Tania A.C.

2009-01-01

The performance of a computed radiography system was evaluated, according to the AAPM Report No. 93. Evaluation tests proposed by the publication were performed, and the following nonconformities were found: imaging p/ate (lP) dark noise, which compromises the clinical image acquired using the IP; exposure indicator uncalibrated, which can cause underexposure to the IP; nonlinearity of the system response, which causes overexposure; resolution limit under the declared by the manufacturer and erasure thoroughness uncalibrated, impairing structures visualization; Moire pattern visualized at the grid response, and IP Throughput over the specified by the manufacturer. These non-conformities indicate that digital imaging systems' lack of calibration can cause an increase in dose in order that image prob/ems can be so/ved. (author)

Digital computed radiography in industrial X-ray testing

International Nuclear Information System (INIS)

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

2001-01-01

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

Clinical Evaluation of a Dual-Side Readout Technique Computed Radiography System in Chest Radiography of Premature Neonates

International Nuclear Information System (INIS)

Carlander, A.; Hansson, J.; Soederberg, J.; Steneryd, K.; Baath, M.

2008-01-01

Background: Recently, the dual-side readout technique has been introduced in computed radiography, leading to an increase in detective quantum efficiency (DQE) compared with the single-side readout technique. Purpose: To evaluate if the increase in DQE with the dual-side readout technique results in a higher clinical image quality in chest radiography of premature neonates at no increase in radiation dose. Material and Methods: Twenty-four chest radiographs of premature neonates were collected from both a single-side readout technique system and a double-side readout technique system. The images were processed in the same image-processing station in order for the comparison to be only dependent on the difference in readout technique. Five radiologists rated the fulfillment of four image quality criteria, which were based on important anatomical landmarks. The given ratings were analyzed using visual grading characteristics (VGC) analysis. Results: The VGC analysis showed that the reproduction of the carina with the main bronchi and the thoracic vertebrae behind the heart was better with the dual-side readout technique, whereas no significant difference for the reproduction of the central vessels or the peripheral vessels could be observed. Conclusions: The results indicate that the higher DQE of the dual-side readout technique leads to higher clinical image quality in chest radiography of premature neonates at no increase in radiation dose. Keywords: Digital radiography; lung; observer performance; pediatrics; thorax

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

International Nuclear Information System (INIS)

Ishida, M.; Shimura, K.; Nakajima, N.; Kato, H.

1988-01-01

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

Imaging suspected cervical spine injury: Plain radiography or computed tomography? Systematic review

Energy Technology Data Exchange (ETDEWEB)

Cain, Gavin [Diagnostic Radiographer, Colchester Hospital University NHS Foundation Trust, Colchester General Hospital, Turner Road, Colchester, CO4 5JL Essex (United Kingdom)], E-mail: gavincain8@hotmail.com; Shepherdson, Jane; Elliott, Vicki; Svensson, Jon [Faculty of Health and Social Care, Anglia Ruskin University, East Road, Cambridge, CB1 9PT Cambridgeshire (United Kingdom); Brennan, Patrick [UCD School of Medicine and Medical Sciences, Health Science Building, Belfield, Dublin 4 (Ireland)

2010-02-15

Aim: (1) to establish which modality offers the greatest accuracy in the detection of cervical spine injury (CSI) Following trauma: plain radiography or computed tomography (CT), and (2) make an evidence-based recommendation for the initial imaging modality of choice. Method: A systematic literature review was performed to identify primary research studies which compare the diagnostic accuracy of plain radiography and CT with the results of a reference standard in the detection of CSI. A search of MEDLINE, EMBASE, CINAHL, Science Direct and Pubmed Central databases was conducted. Results: Ten studies were identified. Critical appraisal identified limitations among all studies. There was heterogeneity in the sensitivity estimates for plain radiography, whereas estimates for CT were consistently high. Examination of the reported sensitivities shows that CT outperforms plain radiography in the detection of CSI. Conclusion: CT is superior to plain radiography in the detection of CSI. However, the optimal imaging strategy depends on the patients' relative risk of injury. If at high-risk cervical CT is indicated. If at low-risk the increased cost and radiation exposure mean that screening CT may not be warranted, good-quality plain radiographs are sufficient.

Progress in digital radiography

International Nuclear Information System (INIS)

Cappelle, A.

2016-01-01

Because of its practical aspect digital radiography is more and more used in the industrial sector. There are 2 kinds of digital radiography. First, the 'computed radiography' that uses a photon-stimulated screen, and after radiation exposure this screen must be read by an analyser to get a digit image. The second type is the 'direct radiography' that allows one to get a digit radiograph of the object directly. Digital radiography uses the same radioactive nuclides as radiography with silver films: cobalt, iridium or selenium. The spatial resolution of digital radiography is less good than with classical silver film radiography but digital radiography offers a better visual contrast. (A.C.)

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

International Nuclear Information System (INIS)

Machado, Alessandra S.; Oliveira, Davi F.; Silva, Aline S.S.; Nascimento, Joseilson R.; Lopes, Ricardo T.

2011-01-01

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

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

Science.gov (United States)

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.

Digital radiography

International Nuclear Information System (INIS)

Zani, M.L.

2002-01-01

X-ray radiography is a very common technique used to check the homogeneity of a material or the inside of a mechanical part. Generally the radiation that goes through the material to check, produced an image on a sensitized film. This method requires time because the film needs to be developed, digital radiography has no longer this inconvenient. In digital radiography the film is replaced by digital data and can be processed as any computer file. This new technique is promising but its main inconvenient is that today its resolution is not so good as that of film radiography. (A.C.)

Fuji computed radiography (FCR) for the diagnosis of spinal disorders

Energy Technology Data Exchange (ETDEWEB)

Kubo, Yoshichika; Waga, Shiro; Kojima, Tadashi

1987-04-01

Since April, 1985, we have, in co-operation with the Fuji Film Co., Ltd., used Fuji Computed Radiography (FCR) in the diagnosis of spinal disorders. FCR is a new computed radiographic system which uses an energy-storage phosphorus panel called an ''Imaging Plate'' as an image sensor. The ''Imaging Plate'' can be used to obtain radiographs in exactly the same way as the screen-film combination used in conventional radiography; X-rays are exposed on the ''Imaging Plate'' instead of X-ray film in the conventional fashion, and then the ''Imaging Plate'' is calculated. The processed digital data from the scans is transformed into a picture by means of digital-to-analogue conversion. The pictures are always clear and beautiful. Plain films of the spine taken by FCR are even clearer, even in the cervicothoracic region, where it is usually difficult to obtain clear cervicothoracic films in conventional radiography. We can obtain much precise information about the spinal posterior osteophytes and grafted bone, even when the patients are immobilized in a Halo apparatus. In myelography, the pictures are also clearer; we can see how the root or roots are compressed, how the dura and cord are involved in patients with cervical disc disease, and even the very narrow space between the cord and an intradural tumor. FCR is thus very useful in observing spinal disorders, either in plain films or myelography.

Fuji computed radiography (FCR) for the diagnosis of spinal disorders

International Nuclear Information System (INIS)

Kubo, Yoshichika; Waga, Shiro; Kojima, Tadashi

1987-01-01

Since April, 1985, we have, in co-operation with the Fuji Film Co., Ltd., used Fuji Computed Radiography (FCR) in the diagnosis of spinal disorders. FCR is a new computed radiographic system which uses an energy-storage phosphorus panel called an ''Imaging Plate'' as an image sensor. The ''Imaging Plate'' can be used to obtain radiographs in exactly the same way as the screen-film combination used in conventional radiography; X-rays are exposed on the ''Imaging Plate'' instead of X-ray film in the conventional fashion, and then the ''Imaging Plate'' is calculated. The processed digital data from the scans is transformed into a picture by means of digital-to-analogue conversion. The pictures are always clear and beautiful. Plain films of the spine taken by FCR are even clearer, even in the cervicothoracic region, where it is usually difficult to obtain clear cervicothoracic films in conventional radiography. We can obtain much precise information about the spinal posterior osteophytes and grafted bone, even when the patients are immobilized in a Halo apparatus. In myelography, the pictures are also clearer; we can see how the root or roots are compressed, how the dura and cord are involved in patients with cervical disc disease, and even the very narrow space between the cord and an intradural tumor. FCR is thus very useful in observing spinal disorders, either in plain films or myelography. (author)

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

Science.gov (United States)

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.

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

Science.gov (United States)

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, pchest 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.

Digital radiography using scintillating screens

International Nuclear Information System (INIS)

Salvini, E.

1988-01-01

This paper briefly describes the technical features of a digital radiographic system based on the principle of scanning laser stimulated luminescence. Such aspects as the physics of the stimulable phosphor detector are dealt with, and image acquisition, processing, and hard-copy output. Automatic analysis of pixel histograms is described, in a qualitative way, together with contrast modifications and spatial filtering. Physical image characteristics are reported. The overall performance of digital radiography is examined, together with the current requirements and its eventual developments

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

International Nuclear Information System (INIS)

Gondo, Gakuji; Ishiwata, Yusuke; Yamashita, Toshinori; Iida, Takashi; Moro, Yutaka

1989-01-01

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

Radiation Effects in Paediatric radiography

International Nuclear Information System (INIS)

Mutwasi, O.

2006-01-01

Diagnostic imaging has evolved from single technique to a field which we have a choice from many modalities. Some without radiation. Radiation producing modalities include plain films (low dose), Fluoroscopy (mid range dose), Computed tomography (high dose). Radiography dose can significantly be influenced in plain radiography by varying speed of screens, cassette construction and type of radiography. E.g. digital or computed. In computed or digital radiography we are no longer able to tell h igh dose b y the quality of images. The final image is by great extend a product of post processing algorithms. It's for this reasons that the basic understanding of the sensitivity and specifying of various types of examinations and of specifically radiation effects is mandatory for a paediatric imager

Computed radiography in neonatal intensive care

International Nuclear Information System (INIS)

Merlo, L.; Bighi, S.; Cervi, P.M.; Lupi, L.

1991-01-01

The Authors report their experience in the employment of a computerized digital radiographic system in Neonatal Intensive Care. The analog screen-film system is replaced by photosensitive imaging plates, scanned after X-ray exposure by a laser that releases the digital image, which can then be manipulated on computer work-stations. In a period of twelve months about 200 chest-abdomen X-ray examinations in Neonatal Intensive Care have been performed using this method with good technical and diagnostic results. The use of digital radiography in the neonatal area is of high interest: this system produces good quality images, there is a reduction in radiation dose and 'retakes', the system allows selective enhancement of different structures and their magnification. (orig.)

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

Science.gov (United States)

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 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.

Detectability of the mediastinal lines : comparison of conventional film-screen radiography and digital radiography

International Nuclear Information System (INIS)

Shin, Hye Young; Park, Kyung Joo; Kang, Doo Kyung; Lee, Kang Lai; Han, Chaing Jin; Suh, Jung Ho

1998-01-01

Using dynamic range compression (DRC) processing, this study compared the detectability of mediastinal lines by conventional film screen radiography (FS) and by storage phosphor digital radiography (DR). We selected 200 normal consecutive chest radiographs (100 FS, 100 DR); dynamic range compression was applied to DR processing and moving grids were used in both systems. Seven mediastinal lines (left paraspinal, right paraspinal, azygoesophageal, left para-aortic, posterio junctional, anterior junctional and right paratracheal) were scored from 0 point to 3 point (0: not visible, 1 : suspiciously visible, 2 : visible, but not clear, 3: clearly visible) according to visibility and sharpness, as agreed by a radiologist and a resident. The differences between the two modalities were compared and analyzed by chi-square test. DR processed with DRC visualizes mediastinal lines more frequently and clearly than conventional FS, and is therefore thought to be useful for the evaluation of mediastinal diseases. (author). 14 refs., 2 tabs., 2 figs

Standard guide for computed radiography

CERN Document Server

American Society for Testing and Materials. Philadelphia

2010-01-01

1.1 This guide provides general tutorial information regarding the fundamental and physical principles of computed radiography (CR), definitions and terminology required to understand the basic CR process. An introduction to some of the limitations that are typically encountered during the establishment of techniques and basic image processing methods are also provided. This guide does not provide specific techniques or acceptance criteria for specific end-user inspection applications. Information presented within this guide may be useful in conjunction with those standards of 1.2. 1.2 CR techniques for general inspection applications may be found in Practice E2033. Technical qualification attributes for CR systems may be found in Practice E2445. Criteria for classification of CR system technical performance levels may be found in Practice E2446. Reference Images Standards E2422, E2660, and E2669 contain digital reference acceptance illustrations. 1.3 The values stated in SI units are to be regarded as the st...

Fine tuning of work practices of common radiological investigations performed using computed radiography system

International Nuclear Information System (INIS)

Livingstone, Roshan S.; Timothy Peace, B.S.; Sunny, S.; Victor Raj, D.

2007-01-01

Introduction: The advent of the computed radiography (CR) has brought about remarkable changes in the field of diagnostic radiology. A relatively large cross-section of the human population is exposed to ionizing radiation on account of common radiological investigations. This study is intended to audit radiation doses imparted to patients during common radiological investigations involving the use of CR systems. Method: The entrance surface doses (ESD) were measured using thermoluminescent dosimeters (TLD) for various radiological investigations performed using the computed radiography (CR) systems. Optimization of radiographic techniques and radiation doses was done by fine tuning the work practices. Results and conclusion: Reduction of radiation doses as high as 47% was achieved during certain investigations with the use of optimized exposure factors and fine-tuned work practices

Discussion of ALTERNATIVE systems for industrial radiography using X-ray films

International Nuclear Information System (INIS)

Vaessen B.; Perdieus, P.; Proegler, H.

1995-01-01

Industrial radiography using X-ray films is an established method of NDE. In the last few years, ''novel developments'' have been put on the market as ''alternatives'' to conventional radiography, as e.g. fluorescent screen/film systems, cost-saving films, wide-latitude films, and storage phosphor films. AGFA as a market leader in the sector of X-ray films for industrial radiography has been testing these alternatives, taking into account image quality, sensitivity, handling in terms of portability, reliability, and the essential functions for NDE: (1) Detection of X-radiation; (2) conversion to optical image; (3) evaluation and validation; (4) documentation and archivation. The advantages and drawbacks, the information transfer capabilities, and the performance from the applications point of view are discussed primarily for fluorescent screen/film systems and storage phophor systems. (orig./MM) [de

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

Science.gov (United States)

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.

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

NARCIS (Netherlands)

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.

2012-01-01

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

Tropical pulmonary eosinophilia: a comparative evaluation of plain chest radiography and computed tomography

Energy Technology Data Exchange (ETDEWEB)

Sandhu Manavijit; Mukhopadhyay Sima; Sharma, S.K. [All India Inst. of Medical Sciences, New Delhi (India). Dept. of Nuclear Medicine

1996-02-01

Plain chest radiography and computed tomography (CT) of the chest were performed on 10 patients with tropical pulmonary eosinophilia (TPE). Chest radiographs revealed bilateral diffuse lesions in the lungs of all the patients with relative sparing of lower lobes in one patient. However, computed tomography revealed bilateral diffuse lung lesions in all of the patients with relative sparing of lower lobes in three patients. In seven (70%) of the 10 patients, CT provided additional information. Computed tomography was found to be superior for the detection of reticulonodular pattern, bronchiectasis, air trapping, calcification and mediastinal adenopathy. No correlation was found between pulmonary function and gas exchange data using CT densities. There was also no correlation between the absolute eosinophil count (AEC) and the radiological severity of lesions. In six patients, high-resolution CT (HRCT) was performed in addition to conventional CT (CCT), and nodularity of lesions was better appreciated in these patients. It is concluded from this study that CT is superior to plain radiography for the evaluation of patients with TPE. 17 refs., 2 tabs., 4 figs.

Computers in dental radiography: a scenario for the future

International Nuclear Information System (INIS)

Webber, R.L.

1985-01-01

The recent emergence of cost-effective computing power makes it possible to integrate sophisticated data-sampling and image-interpretation techniques into dental radiography for the first time. A prototype system is being developed to permit clinical information expressed in three dimensions--plus time--to be made visible almost instantly. The associated X-ray dose for a complete three-dimensional survey of a selected dental region is predicted to be less than that required for a single conventional periapical radiograph exposed on D-speed film

Manual of phosphoric acid fuel cell power plant cost model and computer program

Science.gov (United States)

Lu, C. Y.; Alkasab, K. A.

1984-01-01

Cost analysis of phosphoric acid fuel cell power plant includes two parts: a method for estimation of system capital costs, and an economic analysis which determines the levelized annual cost of operating the system used in the capital cost estimation. A FORTRAN computer has been developed for this cost analysis.

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

Science.gov (United States)

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.

Quality assurance of computed and digital radiography systems

International Nuclear Information System (INIS)

Walsh, C.; Gorman, D.; Byrne, P.; Larkin, A.; Dowling, A.; Malone, J. F.

2008-01-01

Computed radiography (CR) and digital radiography (DR) are replacing traditional film screen radiography as hospitals move towards digital imaging and picture archiving and communication systems (PACS). Both IPEM and KCARE have recently published quality assurance and acceptance testing guidelines for DR. In this paper, the performance of a range of CR and DR systems is compared. Six different manufacturers are included. Particular attention is paid to the performance of the systems under automatic exposure control (AEC). The patient is simulated using a range of thicknesses of tissue equivalent material. Image quality assessment was based on detector assessment protocols and includes pixel value measures as well as subjective assessment using Leeds Test Objects. The protocols for detector assessment cover a broad range of tests and in general detectors (whether DR or CR) performed satisfactorily. The chief limitation in performing these tests was that not all systems provided ready access to pixel values. Subjective tests include the use of the Leeds TO20. As part of this work, suggested reference values are provided to calculate the TO20 image quality factor. One consequence of moving from film screen to digital technologies is that the dynamic range of digital detectors is much wider, and increased exposures are no longer evident from changes in image quality. As such, AEC is a key parameter for CR and DR. Dose was measured using a standard phantom as a basic means of comparing systems. In order to assess the AEC performance, exit doses were also measured while varying phantom thickness. Signal-to-noise ratios (SNRs) were calculated on a number of systems where pixel values were available. SNR was affected by the selection of acquisition protocol. Comparisons between different technologies and collation of data will help refine acceptance thresholds and contribute to optimising dose and image quality. (authors)

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

International Nuclear Information System (INIS)

Sahuinco, Humberto Lazaro Choquepuma; Souza, Ricardo Pires de

2006-01-01

Objective: to determine agreement of three observers on analysis of linear measurements of edentulous maxillae using computed tomography and panoramic radiography in the surgical planning of dental implants. Material and Method: the samples of 17 patients were analyzed with computed tomography and panoramic radiography. Linear measurements obtained from both methods were made at the following anatomical points: left tuberosity, left canine pillar, incisive foramen, right canine pillar and right tuberosity. Kendall's W test was applied to assess the level of agreement. Results: measured W-values from the samples of the anatomical points mentioned above, analyzed with panoramic radiography and computed tomography, were: 0.75 and 0.901; 0.916 and 0.956; 0.843 and 0.964; 0.963 and 0.931; 0.95 and 0.89 respectively. Statistical analysis showed that there was no statistically significant difference. Conclusion: agreement occurred in the measurements of variables.That means that if the three observers were to select an implant to be placed in each of the anatomical regions studied, there would be a good chance whey would choose the same type. (author)

Daily quality control in computed radiography mammography using the manufacturer phantom

International Nuclear Information System (INIS)

Jakubiak, Rosangela R.; Messias, Pricila C.; Oliveira, Carlla M.

2011-01-01

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

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

DEFF Research Database (Denmark)

Einarsdottir, Hildur; Yaroshenko, Andre; Velroyen, Astrid

2015-01-01

In this work we develop a computer-aided diagnosis (CAD) scheme for classification of pulmonary disease for grating-based x-ray radiography. In addition to conventional transmission radiography, the grating-based technique provides a dark-field imaging modality, which utilizes the scattering...... properties of the x-rays. This modality has shown great potential for diagnosing early stage emphysema and fibrosis in mouse lungs in vivo. The CAD scheme is developed to assist radiologists and other medical experts to develop new diagnostic methods when evaluating grating-based images. The scheme consists...... of three stages: (i) automatic lung segmentation; (ii) feature extraction from lung shape and dark-field image intensities; (iii) classification between healthy, emphysema and fibrosis lungs. A study of 102 mice was conducted with 34 healthy, 52 emphysema and 16 fibrosis subjects. Each image was manually...

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

International Nuclear Information System (INIS)

Kaneps, A.J.; Koblik, P.D.; Freeman, D.M.; Pool, R.R.; O'Brien, T.R.

1995-01-01

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

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

International Nuclear Information System (INIS)

Martz, H.E.; Schneberk, D.J.; Roberson, G.P.

1994-07-01

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

Diagnostic Imaging of the Lower Respiratory Tract in Neonatal Foals: Radiography and Computed Tomography.

Science.gov (United States)

Lascola, Kara M; Joslyn, Stephen

2015-12-01

Diagnostic imaging plays an essential role in the diagnosis and monitoring of lower respiratory disease in neonatal foals. Radiography is most widely available to equine practitioners and is the primary modality that has been used for the characterization of respiratory disease in foals. Computed tomography imaging, although still limited in availability to the general practitioner, offers advantages over radiography and has been used diagnostically in neonatal foals with respiratory disease. Recognition of appropriate imaging protocols and patient-associated artifacts is critical for accurate image interpretation regardless of the modality used. Copyright © 2015 Elsevier Inc. All rights reserved.

Magnetic resonance imaging and computed radiography in Achilles tendon rupture

International Nuclear Information System (INIS)

Korenaga, Tateo; Hachiya, Junichi; Miyasaka, Yasuo

1988-01-01

Magnetic Resonance Imaging (MRI) and Computed Radiography (CR) were performed in 15 patients with complete Achilles tendon rupture who were treated conservatively without surgery. MRI was obtained using Toshiba MRT 50 A superconductive machine, operaing at 0.5 Tesla. CR was performed by CR-101, Fuji Medical System. In fresh cases, ruptured tendons showed intermediate signal intensity on T1-weighted images and high intensity on T2-weighted images. Thickening of the tendon was observed in all cases except in very acute stage. Configuration of thickend tendons tends to be dumbbell shape in subacute stage and fusiform in chronic stage of more than six months after the initial trauma. In cases which showed high signal intensity at the ruptured area both on T1 and T2 weighted images, migration of fat into the sapces between the ruptured tendons was considered to be the major source of increased signal intensity. Computed radiography showed thickening of the tendon, blurring of anterior margin of the tendon, and decreased translucency of pre-Achilles fat pad. However, MRI better demonstrated the details of ruptured tendons when compared to CR, and thought to be an usefull way of following up the healing process of the ruptured tendon to facilitate more reasonable judgement of the time of removing plaster casts and stating exercise. (author)

Applications of image plates in neutron radiography and neutron diffraction at BARC, Trombay

International Nuclear Information System (INIS)

Shaikh, A.M.

2013-01-01

Neutron radiography techniques based on Gd, Dy and In metallic foils and X-ray film have been used at this centre since early seventies for various NDT and R and D work in nuclear, defence and aerospace industries. In recent years use of photostimulated luminescence based phosphor imaging plate has been introduced in our work. This has enabled to achieve higher sensitivities and dynamic ranges of recording radiographs with acceptable spatial resolution. It also provides digital image information which is more convenient for quantitative evaluations. Neutron image plates have been used in variety of radiography techniques such as conventional neutron radiography (NR), neutron induced beta radiography (NIBR), hydrogen sensitive epithermal neutron radiography (HYSEN) and for neutron powder diffractometry using Apsara, CIRUS and Dhruva reactors as neutron sources. Recently the image plates have also been used for characterization of thermalized neutron beam from a plasma focus neutron source and recording neutron radiographs. Prior to the utilization image plates have been characterised for their performance. Details of the measurements and applications will be presented. (author)

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

Science.gov (United States)

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.

Automatic measurement system for congenital hip dislocation using a computed radiography

International Nuclear Information System (INIS)

Komori, M.; Minato, K.; Hirakawa, A.; Kuwahara, M.

1988-01-01

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

Computed radiography and the workstation in a study of the cervical spine. Technical and cost implications

International Nuclear Information System (INIS)

Garcia, J. M.; Lopez-Galiacho, N.; Martinez, M.

1999-01-01

To demonstrate the advantages of computed radiography and the workstation in assessing the images acquired in a study of the cervical spine. Lateral projections of cervical spine obtained using a computed radiography system in 63 ambulatory patients were studied in a workstation. Images of the tip of the odontoid process. C1-C2, basion-opisthion and C7 were visualized prior to and after their transmission and processing, and the overall improvement in their diagnostic quality was assessed. The rate of detection of the tip of the odontoid process, C1-C2, the foramen magnum and C/ increased by 17,6, 11 and 14 percentage points, respectively. Image processing improved the diagnostic quality in over 75% of cases. Image processing in a workstation improved the visualization of the anatomical points being studied and the diagnostic quality of the images. These advantages as well as the possibility of transferring the images to a picture archiving and communication system (PACS) are convincing reasons for using digital radiography. (Author) 7 refs

Evaluation of images in a DR system (KD-1000) with new photostimulable phosphors

International Nuclear Information System (INIS)

Yoshita, Hisashi; Kuranishi, Makoto; Nakamura, Mamoru; Kato, Syosuke; Matsui, Mitate.

1994-01-01

The Konica Direct Digitizer KD-1000 is a compact chest acquisition unit in digital radiography. The KD-1000 system uses a photostimulable phosphor detector (RbBr: Tl) and directly converts X-ray quantum into digitized information. We have studied the physical characteristics of the KD-1000, which consists of input-output relationship, spatial resolution and noise. Additionally, we have made a comparison of visual detectability between images from the KD-1000 system and those from a film/screen system (KO-380/HRL), which is used for chest radiography. We have quantified these basic characteristics and established the advantage of the KD-1000 system. (author)

Evaluation of images in a DR system (KD-1000) with new photostimulable phosphors

Energy Technology Data Exchange (ETDEWEB)

Yoshita, Hisashi; Kuranishi, Makoto; Nakamura, Mamoru; Kato, Syosuke (Toyama Medical and Pharmaceutical Univ. (Japan). Hospital); Matsui, Mitate

1994-01-01

The Konica Direct Digitizer KD-1000 is a compact chest acquisition unit in digital radiography. The KD-1000 system uses a photostimulable phosphor detector (RbBr: Tl) and directly converts X-ray quantum into digitized information. We have studied the physical characteristics of the KD-1000, which consists of input-output relationship, spatial resolution and noise. Additionally, we have made a comparison of visual detectability between images from the KD-1000 system and those from a film/screen system (KO-380/HRL), which is used for chest radiography. We have quantified these basic characteristics and established the advantage of the KD-1000 system. (author).

Diagnostic Accuracy of Digital and Conventional Radiography in the Detection of Non-Cavitated Approximal Dental Caries

International Nuclear Information System (INIS)

Abesi, F.; Mirshekar, A.; Moudi, E.; Seyedmajidi, M.; Haghanifar, S.; Haghighat, N.; Bijani, A.

2012-01-01

Radiography plays an important role in the detection of interproximal caries. The aim of the present study was to determine diagnostic accuracy of charge coupled devices, Photo Stimulable Phosphor and film radiography in detecting non-cavitated caries. Seventy-two non-cavitated approximal surfaces of extracted human posterior teeth were radiographed under standardized conditions using three intraoral modalities: charge coupled devices Dixi3 (Planmeca, Finland), PSP Digora PCT (Soredex, Finland), and E-speed film (Kodak, USA). Radiographs were interpreted by four observers and caries lesions were classified as sound (R0), restricted to enamel (R1), reaching the dentinoenamel junction and the outer half of the dentin (R2) and the inner half of the dentin (R3). The teeth were subsequently sectioned for histological analysis which served as the gold standard for radiographic examination. Microscopic examinations showed that the distribution of caries were 63.9% sound, 18.1% enamel, 9.7% dentinoenamel junction and outer half of the dentin and 8.3% into the inner half of the dentin. The sensitivity and specificity of film, charge coupled devices and Photo Stimulable Phosphor for the detection of enamel caries were 38% and 98%; 15% and 96%; and 23% and 98%, respectively. The sensitivity and specificity of film, charge coupled devices and Photo Stimulable Phosphor for the detection of both dentin and enamel caries were 55% and 100%; 45% and 100% ; and 55% and 100%, respectively. The results demonstrated that the diagnostic accuracy of digital images is similar to that of conventional film radiography in the detection of non-cavitated approximal caries.

Digital radiography in NDT applications

International Nuclear Information System (INIS)

Deprins, E.

2004-01-01

A lot of film radiography could be replaced by today's technologies in the field of digital radiography. Only few of these applications have indeed replaced film. The choice to go digital depends on cost, quality requirement, workflow and throughput. Digital images offer a lot of advantages in terms of image manipulation and workflow. But despite the many advantages, a lot of considerations are needed before someone can decide to convert his organization from conventional to digital radiography. This paper gives an overview of all different modalities that can be used in digital radiography with today's technologies, together with the experiences of the pioneers of digital radiography. Film Scanning, Computed Radiography and Digital Radiography by using of different kinds of flat panel detectors all have their specific application fields and customers. What is the status of the technology today, which advantages brings digital radiography, and which are the limitations radiographers have to consider when replacing film by digital systems. (author)

Digital radiography of the chest in pediatric patients

International Nuclear Information System (INIS)

Puig, S.

2003-01-01

The hopes placed in digital radiography have been fulfilled only partly in pediatric radiology. Specifically, the option of gaining reduced radiation exposure in combination with a similar or even improved image quality was hard to realize. The only portable digital system available for a long time were storage phosphors which were disadvantaged by an extremely limited dose-quantum-efficiency (DQE) in comparison to digital flat panel detectors. New developments and the introduction of the dual-reading system led to image qualities comparable to film-screen-systems with high resolution and achievable without dose increase, sometimes even with dose reduction. A study using an animal model suggests that these systems can even be used in preterm infants with very low birth weights. A new portable flat panel detector by Canon may improve digital chest radiography in pediatric patients. (orig.) [de

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

International Nuclear Information System (INIS)

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

2006-01-01

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

An alternative approach to industrial radiography

International Nuclear Information System (INIS)

Broadhead, P.

1981-01-01

An alternative to industrial X-ray film for industrial radiography is described. The experimental system uses film containing approximately 35% of the silver in an industrial type film, which makes the film easier to process, and uses high resolution phosphor screens, which improves the absorption of X-ray photons. Those properties that affect image quality, namely contrast, modulation transfer function and granularity, are discussed in detail for both types of system. A study of low contrast detail in radiographs indicates that for noise limited information the experimental system offers a higher quality than industrial X-ray film of similar speed. (author)

Developments in digital radiography: an equipment update

International Nuclear Information System (INIS)

James, J.J.; O'Connor, P.J.; Davies, A.G.; Cowen, A.R.

2001-01-01

Digital X-ray imaging technology has advanced rapidly over the past few years. This review, particularly aimed at those involved in using and purchasing such technology, is an attempt to unravel some of the complexities of this potentially confusing subject. The main groups of X-ray imaging devices that are considered are digitisers of conventional radiographs, image-intensifier-based fluorography systems, photostimulable phosphor computed radiography, amorphous selenium-based technology for thorax imaging and flat-panel systems. As well as describing these different systems, we look at ways of objectively assessing their image quality. Concepts that are used and explained include spatial resolution, grey-scale bit resolution, signal-to-noise ratio and detective quantum efficiency. An understanding of these basic parameters is vital in making a scientific assessment of a system's performance. Image processing and techniques are also briefly discussed, particularly with reference to their potential effects on image quality. This review aims to provide a basic understanding of digital X-ray imaging technology and enables the reader to make an independent and educated assessment of the relative merits of each system. (orig.)

PENGGUNAAN COMPUTED RADIOGRAPHY UNTUK IDENTIFIKASI MADU LEBAH

Directory of Open Access Journals (Sweden)

SRI MAIYENA

2017-03-01

Full Text Available Research on identification of honey bee using Computed Radiography has been done. The testing was carried out by providing digital radiograph of the three types of honey bee. The voltage of the x-ray generator was varied at 50 kV, 60 kV and 70 kV, while filament current was set at 100 mA and exposure time was at 5 ms. Honey bee was identified based on the image line profile that indicated the distribution of linear absorption coefficient (µ for each sample. The analyses on the image line profile showed that at the voltage of 50 kV and 70 kV the three kinds of the honey bee can be distinguished. However, at the voltage of 60 kV the difference among honey bee was unable to be identified.

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

International Nuclear Information System (INIS)

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

2016-01-01

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. (orig.)

Digital portal radiography in mantle-field irradiation

International Nuclear Information System (INIS)

Scheck, R.J.; Wendt, T.; Panzer, M.

1991-01-01

This paper evaluates the potential of digital luminescence radiography to improve image quality of portal films in mantle-field irradiation. Conventional and digital verification films of an anthropomorphic phantom and 20 patients treated for Hodgkin disease with mantle radiation therapy were obtained with high-energy photon beams. Both conventional films and storage phosphor screens were placed into a cassette with steel intensifier screens. Exposed storage phosphor screens were processed in a semiautomatic mode, with an optimized contrast curve with moderate edge enhancement, and printed as hard copies in a double-image output format. Images were evaluated according to contrast resolution, delineation of anatomic structures, and accuracy of field alignment. Digital portal radiographs were superior to conventional ones with regard to contrast resolution. Thus, they allowed quick and easy detection of relevant structures, although delineation of anatomic structures and field alignments were judged to be equivalent with both techniques. Shorter exposure times for digital images resulted in a reduction in motion artifacts

Conventional radiography and computed tomography of cardiac assist devices

Energy Technology Data Exchange (ETDEWEB)

Scheffel, Hans; Stolzmann, Paul; Desbiolles, Lotus; Leschka, Sebastian; Frauenfelder, Thomas; Schertler, Thomas; Marincek, Borut; Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); Wilhelm, Markus J.; Lachat, Mario [University Hospital Zurich, Clinic for Cardiovascular Surgery, Zurich (Switzerland)

2009-09-15

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

Diagnostic Accuracy of CBCT with Different Voxel Sizes and Intraoral Digital Radiography for Detection of Periapical Bone Lesions: An Ex-Vivo Study

Directory of Open Access Journals (Sweden)

Shirin Sakhdari

2016-10-01

Full Text Available Objectives: This study sought to assess the diagnostic accuracy of cone beam computed tomography (CBCT with different voxel sizes and intraoral digital radiography with photostimulable phosphor (PSP plate for detection of periapical (PA bone lesions.Materials and Methods: In this ex vivo diagnostic study, one-millimeter defects were created in the alveolar sockets of 15 bone blocks, each with two posterior teeth. A no-defect control group was also included. Digital PA radiographs with PSP plates and CBCT scans with 200, 250 and 300μ voxel sizes were obtained. Four observers evaluated the possibility of lesion detection using a 5-point scale. Sensitivity, specificity, positive predictive value (PPV and negative predicative value (NPV were analyzed using one-way ANOVA and Tamhane’s post hoc test. Kappa and weighted kappa statistics were applied to assess intraobserver and interobserver agreements.Results: Cochrane Q test showed no significant difference between PSP and CBCT imaging modalities in terms of kappa and weighted kappa statistics (P=0.675. The complete sensitivity and complete NPV for 200 and 250 μ voxel sizes were higher than those of 300 μ voxel size and digital radiography (P<0.001. No significant difference was noted in other parameters among other imaging modalities (P=0.403.Conclusions: The results showed that high-resolution CBCT scans had higher diagnostic accuracy than PSP digital radiography for detection of artificially created PA bone lesions. Voxel size (field of view must be taken into account to minimize patient radiation dose.Keywords: Diagnosis; Cone-Beam Computed Tomography; Radiography, Dental, Digital; Periapical Periodontitis

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

International Nuclear Information System (INIS)

Roza, Marcello R.; Fioravanti, Maria Clorinda S.; Silva, Luiz Antonio F.; Barriviera, Mauricio; Januario, Alessandro L.; Bezerra, Ana Cristina B.

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

MYTHS vesus reality in computed radiography image quality

International Nuclear Information System (INIS)

Mango, Steve; Castro, Luiz

2009-01-01

As NDE operation - particularly radiographic testing - ransition form analog to digital technologies such as computed radiography (CR), users are learning that there's more to digital image quality than meets the eye. In fact, there are ultiple factors that determine the final perceived image quality of a computed radiograph. Many of these factors are misunderstood, and some are touted as the ''key parameter'' or ''magic bullet'' in producing optiumum image quality, In reality, such claims are oversimplified, and are more marketing hype than reality. The truth?. Perceived image quality results form the cascaded effects of many factor - such as sharpness, system noise, spot size and pixel size, subject contrast, bit depth, radiographic technique, and so on. Many of these factors are within the control of rdiographers or designers of equipment and media. This paper will explain some of these key factors, dispel some of the myths surrounding them, and will show that qualities such as bigger, smaller, more, or less are not always better when it comes to CR image quality. (authors)

Basilar skull fracture in a Thoroughbred colt: Radiography or computed tomography?

Directory of Open Access Journals (Sweden)

Chee Kin Lim

2013-04-01

Full Text Available A two-year-old Thoroughbred colt was presented to the Equine Clinic, Onderstepoort Veterinary Academic Hospital for head trauma after rearing and falling backwards, hitting his head on the ground. Following medical therapy for acute onset neurological impairment secondary to a suspected basilar skull fracture, the horse was anaesthetised and computed tomography of the skull was performed. A diagnosis of a comminuted basilar skull fracture was made and skull radiographs were taken for comparison. The horse was subsequently euthanased owing to the poor prognosis; necropsy findings were compatible with imaging findings. The value and limitation of computed tomography versus radiography for the diagnosis of basilar skull fracture are discussed in this report. Introduction

Basilar skull fracture in a Thoroughbred colt: Radiography or computed tomography?

Directory of Open Access Journals (Sweden)

Chee Kin Lim

2013-04-01

Full Text Available A two-year-old Thoroughbred colt was presented to the Equine Clinic, Onderstepoort Veterinary Academic Hospital for head trauma after rearing and falling backwards, hitting his head on the ground. Following medical therapy for acute onset neurological impairment secondary to a suspected basilar skull fracture, the horse was anaesthetised and computed tomography of the skull was performed. A diagnosis of a comminuted basilar skull fracture was made and skull radiographs were taken for comparison. The horse was subsequently euthanased owing to the poor prognosis; necropsy findings were compatible with imaging findings. The value and limitation of computed tomography versus radiography for the diagnosis of basilar skull fracture are discussed in this report.

Probability of detection - Comparative study of computed and film radiography for high-energy applications

International Nuclear Information System (INIS)

Venkatachalam, R.; Venugopal, M.; Prasad, T.

2007-01-01

Full text of publication follows: Suitability of computed radiography with Ir-192, Co-60 and up to 9 MeV x-rays for weld inspections is of importance to many heavy engineering and aerospace industries. CR is preferred because of lesser exposure and processing time as compared to film based radiography and also digital images offers other advantages such as image enhancements, quantitative measurements and easier archival. This paper describes systemic experimental approaches and image quality metrics to compare imaging performance of CR with film-based radiography. Experiments were designed using six-sigma methodology to validate performance of CR for steel thickness up to 160 mm with Ir- 192, Co-60 and x-ray energies varying from 100 kV up to 9 MeV. Weld specimens with defects such as lack of fusion, penetration, cracks, concavity, and porosities were studied for evaluating radiographic sensitivity and imaging performance of the system. Attempts were also made to quantify probability of detection using specimens with artificial and natural defects for various experimental conditions and were compared with film based systems. (authors)

MO-G-18A-01: Radiation Dose Reducing Strategies in CT, Fluoroscopy and Radiography

International Nuclear Information System (INIS)

Mahesh, M; Gingold, E; Jones, A

2014-01-01

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 panel 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

Pediatric radiation dose management in digital radiography

International Nuclear Information System (INIS)

Neitzel, U.

2004-01-01

Direct digital radiography (DR) systems based on flat-panel detectors offer improved dose management in pediatric radiography. Integration of X-ray generation and detection in one computer-controlled system provides better control and monitoring

Two K versus 4 K storage phosphor chest radiography: detection performance and image quality

International Nuclear Information System (INIS)

Koelblinger, Claus; Weber, Michael; Sailer, Johannes; Cartes-Zumelzu, Fabiola; Prokop, Mathias; Schaefer-Prokop, Cornelia

2007-01-01

The purpose of this study was to evaluate the effect of matrix size (4-K versus 2-K) in digital storage phosphor chest radiographs on image quality and on the detection of CT-proven thoracic abnormalities. In 85 patients who underwent a CT of the thorax, we obtained two additional posteroanterior storage phosphor chest radiographs, one with a matrix size of 3,520 x 4,280 (=4-K) and the other with a matrix size of 1,760 x 2,140 (=2-K). Acquisition, processing and presentation parameters were identical for all radiographs. Two radiologists evaluated the presence of mediastinal, pleural, and pulmonary abnormalities on hard copies of the radiographs, applying ROC analysis. In addition, four radiologists were asked to subjectively rank differences in image quality and to assess the demarcation of anatomic landmarks comparing the images in a blinded side-by-side manner. These data were analyzed using a two-sided binomial test with a significance level of P<0.05. Both tests, the ROC analysis of the detection performance and the binomial test of the subjective quality ratings, did not reveal significant differences between the two matrix sizes. Compared to 2-K radiographs, 4-K storage phosphor chest radiographs do not provide superior detection performance or image quality when evaluated in identical hard copy formats. (orig.)

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

Science.gov (United States)

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 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.

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

International Nuclear Information System (INIS)

De Boo, D.W.; Weber, M.; Deurloo, E.E.; Streekstra, G.J.; Freling, N.J.; Dongelmans, D.A.; Schaefer-Prokop, C.M.

2011-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-08-15

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

Management of pediatric radiation dose using Fuji computed radiography

International Nuclear Information System (INIS)

MacCutcheon, D.W.

2004-01-01

This paper describes the technical details of Fuji Computed Radiography (FCR) and its use as it relates to managing pediatric dose for X-ray examinations. Since its introduction in 1983, Fuji (Fuji Photo Film Co., Ltd.) has developed an extensive set of menu selections with default processing algorithms and corresponding display processing parameters modified for all pediatric exam types. Continued development of imaging plate technology, FCR reader design and image processing have all contributed to improving image quality and creating the opportunity to lower the dose required for pediatric exams. Fuji continues to advance CR and electronic imaging technologies; some of these developments, that may enable lower dose examinations for pediatric imaging in the future, are also described in this paper. (orig.)

Absorbed doses for patients undergoing panoramic radiography, cephalometric radiography and CBCT

Directory of Open Access Journals (Sweden)

Małgorzata Wrzesień

2017-10-01

Full Text Available Objectives: Contemporary dental radiology offers a wide spectrum of imaging methods but it also contributes to an increase in the participation of dental radiological diagnosis in the patient’s exposure to ionizing radiation. The aim of this study is to determine the absorbed doses of the brain, spinal column, thyroid and eye lens for patients during panoramic radiography, cephalometric radiography and cone beam computed tomography (CBCT. Material and Methods: The thermoluminescent dosimetry and anthropomorphic phantom was used for measuring the doses. The 15 panoramic, 4 cephalometric and 4 CBCT exposures were performed by placing high-sensitivity thermoluminescent detectors (TLD in 18 anatomical points of the phantom. Results: The maximum absorbed dose recorded during performed measurements corresponds to the point representing the brainstem and it is 10 mGy. The dose value recorded by the TLD placed in the thyroid during CBCT imaging in relation to the panoramic radiography differs by a factor of 13.5. Conclusions: Cone beam computed tomography, in comparison with panoramic or cephalometric imaging technique, provides higher radiation doses to the patients. Int J Occup Med Environ Health 2017;30(5:705–713

Filmless radiography - present possibilities and direction of future developing

International Nuclear Information System (INIS)

Wocial, A.; Wojciechowski, Z.A.; Rozenblicki, Z.

2008-01-01

The paper presents introduction for new filmless radiography like CR Computed Radiography and DR Digital Radiography direct and non direct. The main factors are considered, which determine classification to different type of radiography. For each technique authors describe advantages and disadvantages supporting by practice examples. Paper contains a lot of practical information about a most of existing radiographic equipment at the NDT market. (author)

Glandular dose and image quality control in mammography facilities with computerized radiography systems

International Nuclear Information System (INIS)

Dantas, Marcelino Vicente de Almeida

2010-01-01

Breast cancer is the most common cancer among women, and early detection is critical to its diagnosis and treatment. To date, the most effective method for early detection of breast cancer has been x-ray mammography for which the screen/film (SF) technique has been the gold standard. However, even though SF combinations have been improved and optimized over the years for breast imaging, there are some critical limitations, including a narrow exposure range, image artifacts, film processing problems, and inflexibility in image processing and film management. In recent years, digital mammography has been introduced in cancer screening programmes with the screen/film techniques gradually being phased out. Computed radiography (CR), also commonly known as photostimulable phosphor (PSP) imaging or storage phosphor, employs reusable imaging plates and associated hardware and software to acquire and to display digital projection radiographs. In this work, a protocol model was tested for performing image quality control and average glandular dose (AGD) evaluation in 19 institutions with computed radiography systems for mammography. The protocol was validated through tests at the Laboratorio de Radioprotecao Aplicada a Mamografia (LARAM) from the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN). The image quality visual evaluation of CDMAM phantom showed that 53% of the facilities were able to produce images of excellent quality. Furthermore, the automated evaluation of image quality, using the analyze software cdcom.exe, showed that 57% of the images were considered to be of good quality. The detector linearity test showed that the CR response is very linear, where 95% of facilities evaluated were considered to be compliant. For the image noise was found that only 20% of facilities are in agreement with the parameters established for this test. The average glandular doses, which patients may be getting to perform an examination, were below the action levels

Industrial radiography with Ir-192 using computed radiographic technique

International Nuclear Information System (INIS)

Ngernvijit, Narippawaj; Punnachaiya, Suvit; Chankow, Nares; Sukbumperng, Ampai; Thong-Aram, Decho

2003-01-01

The aim of this research is to study the utilization of a low activity Ir-192 gamma source for industrial radiographic testing using the Computed Radiography (CR) system. Due to a photo-salbutamol Imaging Plate (I P) using in CR is much more radiation sensitive than a type II film with lead foil intensifying screen, the exposure time with CR can be significantly reduced. For short-lived gamma-ray source like Ir-192 source, the exposure time must be proportionally increased until it is not practical particularly for thick specimens. Generally, when the source decays to an activity of about 5 Ci or less, it will be returned to the manufacturer as a radioactive waste. In this research, the optimum conditions for radiography of a 20 mm thick welded steel sample with 2.4 Ci Ir-192 was investigated using the CR system with high resolution image plate, i.e. type Bas-SR of the Fuji Film Co. Ltd. The I P was sandwiched by a pair of 0.25 mm thick Pb intensifying sere en. Low energy scattered radiations was filtered by placing another Pb sheet with a thickness of 3 mm under the cassette. It was found that the CR image could give a contrast sensitivity of 2.5 % using only 3-minute exposure time which was comparable to the image taken by the type II film with Pb intensifying screen using the exposure time of 45 minutes

A note on digital dental radiography in forensic odontology.

Science.gov (United States)

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.

Infection control in digital intraoral radiography: evaluation of microbiological contamination of photostimulable phosphor plates in barrier envelopes.

Science.gov (United States)

MacDonald, David S; Waterfield, J Douglas

2011-01-01

The detectors (both solid-state sensors and photostimulable phosphor [PSP] plates) used for digital intraoral radiography cannot be autoclaved, and barriers are typically used to prevent the spread of infection. The aim of this study was to determine the effectiveness of a barrier envelope system for PSP plates. Disinfected PSP plates were aseptically inserted into barrier envelopes and placed in a periapical location. One PSP plate was placed in each of 28 patients, and 12 plates in each of 2 volunteers (D.S.M., J.D.W.). After retrieval, each PSP plate was removed from its barrier envelope, immersed in trypticase soy broth and aliquots were plated on trypticase soy agar. Bacterial colonies were counted 2 days later. Fifty-two PSP plates in barrier envelopes were evaluated for contamination. Quality assurance of the PSP plates before clinical placement revealed defects in the integrity of 4 barrier envelopes, caused by forceps-related damage or failure to achieve a uniform seal. These defects allowed substantial contamination. Contamination also occurred as a result of failure to extract the PSP plate from the barrier envelope cleanly. Of the 44 barriers with no obvious defects that were placed by either final-year dental students or a radiologist, only 3 allowed bacterial contamination of the PSP plate. Detectors contained in barrier envelopes remain a potential source of contamination. PSP plates must be disinfected between removal from a contaminated barrier envelope and placement in a new barrier envelope. In addition, placement into the barrier envelope should ideally be carried out under aseptic conditions. Finally, the integrity of each sealed barrier envelope must be verified visually before release to the clinic.

Comparison of radiography, computed tomography and magnetic resonance imaging in the detection of sacroiliitis accompanying ankylosing spondylitis

International Nuclear Information System (INIS)

Yu, Wei; Feng Feng; Yang Hongzen; Jiang Ming; Dion, E.; Genant, H.K.

1998-01-01

Objective. To compare magnetic resonance (MR) imaging, computed tomography (CT), and radiography in the detection of sacroiliitis accompanying ankylosing spondylitis (AS). Design and subjects. Nine volunteers and 24 patients were recruited. Radiography, CT, and MR imaging were completed within a 1-week period in 24 patients with AS. In precontrast MR examination, spin-echo T1, fast spin-echo T2, and gradient echo with rephasing T2* images were obtained without fat saturation using a 0.3-T imager for all volunteers and patients. Postcontrast MR examination was performed using the same precontrast SE T1 sequence for patients with AS. Results and conclusions. MR imaging directly showed the normal cartilage in all 16 sacroiliac joints of the 8 volunteers. In the 24 patients with AS, cartilage abnormalities were observed in 42 sacroiliac joints. More diagnoses of sacroiliitis were made using MR and CT imaging than using radiography (P<0.001). Therefore, low-field-strength MR can be useful in detecting early sacroiliitis in patients with AS. MR imaging was able to reveal early cartilage changes and bone marrow edema, which could not be found by either CT or radiography. (orig.)

Portable Digital Radiography and Computed Tomography Manual

Energy Technology Data Exchange (ETDEWEB)

2007-11-01

This user manual describes the function and use of the portable digital radiography and computed tomography (DRCT) scanner. The manual gives a general overview of x-ray imaging systems along with a description of the DRCT system. An inventory of the all the system components, organized by shipping container, is also included. In addition, detailed, step-by-step procedures are provided for all of the exercises necessary for a novice user to successfully collect digital radiographs and tomographic images of an object, including instructions on system assembly and detector calibration and system alignment. There is also a short section covering the limited system care and maintenance needs. Descriptions of the included software packages, the DRCT Digital Imager used for system operation, and the DRCT Image Processing Interface used for image viewing and tomographic data reconstruction are given in the appendixes. The appendixes also include a cheat sheet for more experienced users, a listing of known system problems and how to mitigate them, and an inventory check-off sheet suitable for copying and including with the machine for shipment purposes.

Accuracy of digital radiography and cone beam computed tomography on periapical radiolucency detection in endodontically treated teeth.

Science.gov (United States)

Venskutonis, Tadas; Daugela, Povilas; Strazdas, Marijus; Juodzbalys, Gintaras

2014-04-01

The aim of the present study was to compare the accuracy of intraoral digital periapical radiography and cone beam computed tomography in the detection of periapical radiolucencies in endodontically treated teeth. Radiographic images (cone beam computed tomography [CBCT] scans and digital periapical radiography [PR] images) from 60 patients, achieved from September 2008 to July 2013, were retrieved from databases of the Department of Oral Diseases, Lithuanian University of Health Sciences. Twenty patients met inclusion criteria and were selected for further evaluation. In 20 patients (42.4 [SD 12.1] years, 65% men and 35% women) a total of 35 endodontically treated teeth (1.75 [SD 0.91]; 27 in maxilla and 8 in mandible) were evaluated. Overall, it was observed a statistical significant difference between the number of periapical lesions observed in the CBCT (n = 42) and radiographic (n = 24) examinations (P cone beam computed tomography scans were more accurate compared to digital periapical radiographs for detecting periapical radiolucencies in endodontically treated teeth. The difference was more pronounced in molar teeth.

Satisfaction of Search in Chest Radiography 2015.

Science.gov (United States)

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 chest radiography (P 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.

Quantitative neutron radiography using neutron absorbing honeycomb

International Nuclear Information System (INIS)

Tamaki, Masayoshi; Oda, Masahiro; Takahashi, Kenji; Ohkubo, Kohei; Tasaka, Kanji; Tsuruno, Akira; Matsubayashi, Masahito.

1993-01-01

This investigation concerns quantitative neutron radiography and computed tomography by using a neutron absorbing honeycomb collimator. By setting the neutron absorbing honeycomb collimator between object and imaging system, neutrons scattered in the object were absorbed by the honeycomb material and eliminated before coming to the imaging system, but the neutrons which were transmitted the object without interaction could reach the imaging system. The image by purely transmitted neutrons gives the quantitative information. Two honeycombs were prepared with coating of boron nitride and gadolinium oxide and evaluated for the quantitative application. The relation between the neutron total cross section and the attenuation coefficient confirmed that they were in a fairly good agreement. Application to quantitative computed tomography was also successfully conducted. The new neutron radiography method using the neutron-absorbing honeycomb collimator for the elimination of the scattered neutrons improved remarkably the quantitativeness of the neutron radiography and computed tomography. (author)

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

International Nuclear Information System (INIS)

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

2013-01-01

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 -950 . The diagnostic performance of tomosynthesis was significantly superior to that of radiography for the detection of pulmonary emphysema. In both tomosynthesis and radiography, the sensitivity was affected by the LAA -950 . (orig.)

An investigation of automatic exposure control calibration for chest imaging with a computed radiography system

International Nuclear Information System (INIS)

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

2014-01-01

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 (eNEQ m ), 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 eNEQ m  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. (paper)

An investigation of automatic exposure control calibration for chest imaging with a computed radiography system.

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Comparison of the image quality of digital radiography system and film screen system - Radiologist' rating of the visibility of normal anatomic - Structures in chest PA, Skull radiograph and K. U. B

International Nuclear Information System (INIS)

Song, Kounn Sik; Kim, Young Goo; Lee, Jong Beum; Kim, Kun Sang

1987-01-01

Digital image acquisition and display is widely used in computed tomography, ultrasonography, digital subtraction angiography, nuclear medicine and magnetic resonance image. But most of the radiological examinations performed in radiology department are made by using conventional system. The development of the digital radiography system is essential if totally digitized radiology department is desired. The advantages of digitizing the radiographic information are usually discussed in terms of PACS (picture archiving and communication system), furthermore there are many other advantages such as contrast modification, spatial filtering subtraction and superimposition of the images through the image processing by computer. Currently several approaches are under development or in clinical use, the most promising approach is the use of imaging plate composed of photostimulate phosphors such as barium fluorohalide crystal read with a He-Ne laser to produce digital radiographic images. Another promising approach is scan projection radiography. The authors performed the clinical study of comparing the image qualities of digital radiography system using scanning laser luminescence (FCR) and conventional film-screen system in chest PA, skull radiography and K. U. B. in terms of the visibility of the normal anatomic structure rating those (qualities) on a scale of 0 to 3 and obtained the following results. Normal contrast digital images are comparable to conventional film-screen images, but the images of high frequency enhancement is far superior to conventional film-screen especially in peripherally located structures such as skin, subcutaneous fat, musculoskeletal systems, nasal bone, inner and outer table of the skull including the diploic space, paranasal sinuses, nasopharynx and larynx, trachea and main bronchi, mediastinal structures, retrocardiac and subphrenic vascular markings. Another promising aspects of digital radiography system is its wide exposure latitude and

Digital radiography: description and user's guide

International Nuclear Information System (INIS)

Berthel, A.; Bonin, Th.; Cadilhon, S.; Thiery, Ch.; Chatellier, L.; Kaftandjian, V.; Honorat, Ph.; Torrent, J.; Le Brun, A.; Maglaive, J.C.; Moreau, Ph.; Pettier, J.L.; Rebuffel, V.; Roenelle, P.; Roussilhe, J.; Staat, St.; Tahon, M.

2007-01-01

The presented document arises from the work of the group 'Digital Radiography and sensors' of COFREND. It is a collective work of synthesis aimed to analyze the quality parameters of digital images influencing the answer and the diagnosis brought to a given industrial problem. Five families of digital sensors have been studied: 1. Image Intensifier coupled with CCD devices - 2. scintillators coupled with a CCD device- 3. Flat Panels with indirect conversion - 4. Flat Panels with direct electric conversion - 5. Photostimulable Storage Phosphor Screens). In particular, concerning a complete imaging chain, it deals with the notions of magnification, blur (unsharpness) (geometrical, kinetic or internal to the very sensor), noises, scattered radiation, spatial resolution, which is different from the one of analog detectors such as films, Contrast to Noise Ratio (CNR), sensitivity using IQIs, dynamic range, detection quantum efficiency, persistence and temporal resolution. This document is not a standard; it must be understood as a user's guide, and it approaches some essentials corrections to bring to a sensor in order to optimize his efficiency without losing information during the pre-processing phase in the radiographic acquisition. It also introduces some image processing tools commonly used. It can be used as a source document to the future elaboration of a standardisation document. It augurs not at all of the choice of a digital sensor with regard to the traditional radiographic film, but gives bases of reflection to a radio user for a sensible transfer from the classic radiography to the digital radiography. (authors)

Broadening the radiography spectrum

International Nuclear Information System (INIS)

Waswa, L.; Mutwasi, O.; Kioko, J.

2006-05-01

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

Subtraction radiography and computer assisted densitometric analyses of standardized radiographs. A comparison study with /sup 125/I absorptiometry

Energy Technology Data Exchange (ETDEWEB)

Ortmann, L.F.; Dunford, R.; McHenry, K.; Hausmann, E.

1985-01-01

A standardized radiographic series of incrementally increasing alveolar crestal defects in skulls were subjected to analyses by subtraction radiography and computer assisted quantitative densitometric analysis. Subjects were able to detect change using subtraction radiography in alveolar bone defects with bone loss in the range of 1-5 percent as measured by /sup 125/I absorptiometry. Quantitative densitometric analyses utilizing radiographic pairs adjusted for differences in contrast (gamma corrected) can be used to follow longitudinal changes at a particular alveolar bone site. Such measurements correlate with change observed by /sup 125/I absorptiometry (r=0.82-0.94). (author).

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

International Nuclear Information System (INIS)

Sánchez, M.G.; Juste, B.; Vidal, V.; Verdú, G.; Mayo, P.; Rodenas, F.

2014-01-01

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

Accuracy of cone beam computed tomography, intraoral radiography, and periodontal probing for periodontal bone defects measurement

Directory of Open Access Journals (Sweden)

Eskandarlo A

2011-02-01

Full Text Available "nBackground and Aims: Cone beam computed tomography (CBCT produces high-quality data about diagnosis and periodontal treatment. To date, there is not enough research regarding periodontal bone measurement using CBCT. The aim of this study was to compare the accuracy of CBCT in measuring periodontal defects to that of intraoral radiography and probing methods."nMaterials and Methods: Two-hundred and eighteen artificial osseous defects (buccal and lingual infrabony, interproximal, horizontal, crater, dehiscence and fenestration defects were created on 13 mandibles of dry skulls. The mandibles were put into a plexiglass box full of water to simulate soft tissue. CBCT images, radiographic images taken with parallel technique and direct measurements using a WHO periodontal probe were recorded and compared to a standard reference (digital caliper. Inter and intra observe consistencies were assessed using Intra class correlation coefficient and pearson correlation."nResults: Inter and intra observer consistencies were high for CBCT and probing methods (ICC- Intra class correlation coefficient>88%, but moderate for intraoral radiography (ICC-Intra class correlation coefficient > 54%. There were not any significant differences between observers for all techniques (P>0/05. According to paired T-test analysis, mean difference for CBCT technique (0.01 mm was lower than that for probing (0.04 mm and radiography (0.62 mm. CBCT was able to measure all kinds of lesions, but radiography could not measure defects in the buccal and lingual sites."nConclusion: All three modalities are useful for identifying periodontal defects. Compared to probing and radiography, the CBCT technique has the most accuracy in measuring periodontal defects.

Two K versus 4 K storage phosphor chest radiography: detection performance and image quality

NARCIS (Netherlands)

Koelblinger, Claus; Prokop, Mathias; Weber, Michael; Sailer, Johannes; Cartes-Zumelzu, Fabiola; Schaefer-Prokop, Cornelia

2007-01-01

The purpose of this study was to evaluate the effect of matrix size (4-K versus 2-K) in digital storage phosphor chest radiographs on image quality and on the detection of CT-proven thoracic abnormalities. In 85 patients who underwent a CT of the thorax, we obtained two additional posteroanterior

Some malpractices in application of computed radiography

International Nuclear Information System (INIS)

Liu Ruihong; Jia Shaotian; Wang Yusheng; Li Baohua; Chen Lin; Wang Zhenguang; Liu Jianxin; Gong Jingyue; Liu Daoyong; Xie Xuesong

2007-01-01

Objective: To improve the CR image quality and to promote the digital image standard constitution by analyzing the common problems and malpractices in application of computed radiography. Methods: Phenomenon and reasons of 107 CR junk-films from nine three-'A'-hospitals were analyzed, discussed, recorded, and statistised by 20 radiologists, radiographers and engineers. Results: Among 107 junk films, there are 36 cases (33.64%) of incorrect operations, 29 cases (27.10%) of artifacts in reading and transferring the data of IP, 15 cases (14.02%) of artifacts in IP system, and 13 cases (12.15%) of selection of inappropriate radiographic parameters, and 9 cases (8.41%) of printer-failures, and 5 cases (4.67%) of inappropriate post-processing techniques. By analyzing the reasons of 107 junk films we found that 60.74% were due to less responsibilities and incorrect operations, and 35.51% were due to new problems in CR techniques, and other were due to inappropriate post-processing techniques. Conclusion: Responsibilities, operation regulations, digital image quality standards, studying of new techniques and appropriate use of the post-processing techniques are the key points for improving the CR image quality and the diagnosis level. (authors)

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

International Nuclear Information System (INIS)

Rabinowitz, T.G.; Efremidis, S.C.; Cohen, B.; Dan, S.; Efremidis, A.; Chahinian, A.P.; Teirstein, A.S.

1982-01-01

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

BaFCl:Eu2+, a new phosphor for X-ray-intensifying screens

International Nuclear Information System (INIS)

Stevels, A.L.N.; Pingault, F.

1975-01-01

A number of phosphors for X-ray-intensifying screens have been evaluated by calculating figures of merit. On use in combination with standard (''blue''-sensitive) X-ray film, BaFCl:Eu 2+ and BaFBr:Eu 2+ give better performance than the traditional CaWO 4 and more recently developed UV or blue-emitting materials (e.g., sulphates and y-oxysulphides). The calculated figures of merit of BaFCl:Eu 2+ or BaFBr:Eu 2+ /standard-film combinations are comparable to those of Gd 2 O 2 S:Tb/green-sensitive X-ray film systems. The preparation of optimal fluorohalide:Eu 2+ phosphors involves proper formation of the host lattice, complete reduction of Eu 3+ ions as well as elimination of afterglow. Measurements on powders and experimental screens indicate that by using BaFCl:Eu 2+ screens in radiography, important dose reductions can be achieved without the necessity of using other than standard (''blue''-sensitive) X-ray films

Medical Imaging 4: Image formation

International Nuclear Information System (INIS)

Schneider, R.H.

1990-01-01

This book contains papers relating to the 1990 meeting of The International Society for Optical Engineering. Included are the following papers: Effect of protective layer on Resolution Properties of Photostimulable Phosphor Detector for Digital Radiographic System, Neural Network Scatter Correction Technique for Digital Radiography, Use of Computer Radiography for Portal Imaging

Evaluation of an image receptor for computed radiography system in mammography

International Nuclear Information System (INIS)

Dantas, Marcelino V.A.; Rosado, Paulo H.G.; Santana, Priscila C.; Alvarenga, Frederico L.; Nogueira, Maria S.

2009-01-01

In this work, the performance of an image receptor for computed radiography system, Kodak CR850, was assessed through tests, recommended by the European protocol, with a specific image plate for mammography where were analyzed the Contrast-to-noise ratio (CNR) and uniformity and linearity of detector. The CNRs were 14.1, 11.7, 10.3, 8.4, 7.1 and 5.9 for 2, 3, 4, 5, 6 and 7 cm polymethylmethacrylate (PMMA) thickness, respectively. The linearity between detector response and dose, obtained a correlation coefficient (R 2 ) greater than 0.99, and the maximum variation found in the detector uniformity calculation was 3.94 in the lower right corner. (author)

Comparison of cone beam computed tomography and conventional panoramic radiography in assessing the topographic relationship between the mandibular canal and impacted third molars

International Nuclear Information System (INIS)

Choi, Hyung Soo; Kim, Gyu Tae; Choi, Yong Suk; Hwang, Eui Hwan

2008-01-01

To assess the diagnostic accuracy and value in an imaging technique field through the comparison of cone beam computed tomography and conventional panoramic radiography in assessing the topographic relationship between the mandibular canal and impacted third molars. Participants consisted of 100 patients offered the images through cone beam computed tomography and panoramic radiography. PSR-9000TM Dental CT system (Asahi Roentgen Ind. Co., Ltd, Japan) was used as the unit of cone beam computed tomography. CE-II (Asahi Roentgen Ind. Co., Ltd, Japan) and Pro Max (Planmeca Oy, Finland) were used as the unit of panoramic radiography. The images obtained through panoramic radiography were classified into 3 types according to the distance between mandibular canal and root of mandibular third molar. And they were classified into 4 types according to the proximity of radiographic feature. The images obtained through cone beam computed tomography based on the classification above were classified into 4 types according to the location between the mandibular canal and the root and were analyzed. And they were classified into buccal, inferior, lingual, and between roots, according to the location between mandibular canal and root. The data were statistically analyzed and estimated by x2-test. 1. There was no statistical significance according to 3 types (type I, type II, type III) through CBCT. 2. The results of 4 types (type A, type B, type C, type D) through CBCT were as high prevalence of CBCT 1 in type A, CBCT 2 in type B, CBCT 3 in type C, and CBCT1 in type D and those of which showed statistical significance (P value=0.03). 3. The results according to location between mandibular canal and root through CBCT recorded each 49, 25, 17, 9 as buccal, inferior, lingual, between roots. When estimating the mandibular canal and the roots through the panoramic radiography, it could be difficult to drive the views of which this estimation was considerable. Thus it is required to

Radiography - A new field among health sciences in Finland

International Nuclear Information System (INIS)

Pakarinen, Ritva; Jussila, Aino-Liisa

2007-01-01

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

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

Science.gov (United States)

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.

Neutron radiography

International Nuclear Information System (INIS)

Hrdlicka, Z.

1977-01-01

Neutron radiography is a radiographic method using a neutron beam of a defined geometry. The neutron source usually consists of a research reactor, a specialized neutron radiography reactor or the 252 Cf radioisotope source. There are two types of the neutron radiography display system, viz., a system producing neutron radiography images by a photographic process or a system allowing a visual display, eg., using a television monitor. The method can be used wherever X-ray radiography is used except applications in the radiography of humans. The neutron radiography unit at UJV uses the WWR-S reactor as the neutron source and both types of the above mentioned display system. (J.P.)

Standard practice for classification of computed radiology systems

CERN Document Server

American Society for Testing and Materials. Philadelphia

2005-01-01

1.1 This practice describes the evaluation and classification of a computed radiography (CR) system, a particular phosphor imaging plate (IP), system scanner and software, in combination with specified metal screens for industrial radiography. It is intended to ensure that the evaluation of image quality, as far as this is influenced by the scanner/IP system, meets the needs of users. 1.2 The practice defines system tests to be used to classify the systems of different suppliers and make them comparable for users. 1.3 The CR system performance is described by signal and noise parameters. For film systems, the signal is represented by gradient and the noise by granularity. The signal-to-noise ratio is normalized by the basic spatial resolution of the system and is part of classification. The normalization is given by the scanning aperture of 100 µm diameter for the micro-photometer, which is defined in Test Method E1815 for film system classification. This practice describes how the parameters shall be meas...

Evaluation of the diagnostic accuracy of four-view radiography and conventional computed tomography analysing sacral and pelvic fractures in dogs.

Science.gov (United States)

Stieger-Vanegas, S M; Senthirajah, S K J; Nemanic, S; Baltzer, W; Warnock, J; Bobe, G

2015-01-01

The purpose of our study was (1) to determine whether four-view radiography of the pelvis is as reliable and accurate as computed tomography (CT) in diagnosing sacral and pelvic fractures, in addition to coxofemoral and sacroiliac joint subluxation or luxation, and (2) to evaluate the effect of the amount of training in reading diagnostic imaging studies on the accuracy of diagnosing sacral and pelvic fractures in dogs. Sacral and pelvic fractures were created in 11 canine cadavers using a lateral impactor. In all cadavers, frog-legged ventro-dorsal, lateral, right and left ventro-45°-medial to dorsolateral oblique frog leg ("rollover 45-degree view") radiographs and a CT of the pelvis were obtained. Two radiologists, two surgeons and two veterinary students classified fractures using a confidence scale and noted the duration of evaluation for each imaging modality and case. The imaging results were compared to gross dissection. All evaluators required significantly more time to analyse CT images compared to radiographic images. Sacral and pelvic fractures, specifically those of the sacral body, ischiatic table, and the pubic bone, were more accurately diagnosed using CT compared to radiography. Fractures of the acetabulum and iliac body were diagnosed with similar accuracy (at least 86%) using either modality. Computed tomography is a better method for detecting canine sacral and some pelvic fractures compared to radiography. Computed tomography provided an accuracy of close to 100% in persons trained in evaluating CT images.

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

Science.gov (United States)

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.

Method and Apparatus for Computed Imaging Backscatter Radiography

Science.gov (United States)

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

Phosphors

International Nuclear Information System (INIS)

1975-01-01

This invention relates to phosphors that can be used in fluorescent lamps and display devices. The phosphor is comprised of a halophosphate of calcium and/or strontium of apatite crystal structure activated with trivalent cerium and trivalent terbium. The phosphor can further include manganese. Preferably, the phosphor includes up to 10% by weight of one or more of the alkali metals lithium, sodium and potassium in the form of a compound or compounds thereof. The emissions appear as a number of fairly narrow discrete bands. The temperature of preparation is 1000degC (as opposed to the usual 1450degC), therefore reducing costs (less energy is needed, more crucibles are readily obtainable and there is no need for special conditions to enable crucibles to overcome thermal shock)

Modeling granular phosphor screens by Monte Carlo methods

International Nuclear Information System (INIS)

Liaparinos, Panagiotis F.; Kandarakis, Ioannis S.; Cavouras, Dionisis A.; Delis, Harry B.; Panayiotakis, George S.

2006-01-01

The intrinsic phosphor properties are of significant importance for the performance of phosphor screens used in medical imaging systems. In previous analytical-theoretical and Monte Carlo studies on granular phosphor materials, values of optical properties, and light interaction cross sections were found by fitting to experimental data. These values were then employed for the assessment of phosphor screen imaging performance. However, it was found that, depending on the experimental technique and fitting methodology, the optical parameters of a specific phosphor material varied within a wide range of values, i.e., variations of light scattering with respect to light absorption coefficients were often observed for the same phosphor material. In this study, x-ray and light transport within granular phosphor materials was studied by developing a computational model using Monte Carlo methods. The model was based on the intrinsic physical characteristics of the phosphor. Input values required to feed the model can be easily obtained from tabulated data. The complex refractive index was introduced and microscopic probabilities for light interactions were produced, using Mie scattering theory. Model validation was carried out by comparing model results on x-ray and light parameters (x-ray absorption, statistical fluctuations in the x-ray to light conversion process, number of emitted light photons, output light spatial distribution) with previous published experimental data on Gd 2 O 2 S:Tb phosphor material (Kodak Min-R screen). Results showed the dependence of the modulation transfer function (MTF) on phosphor grain size and material packing density. It was predicted that granular Gd 2 O 2 S:Tb screens of high packing density and small grain size may exhibit considerably better resolution and light emission properties than the conventional Gd 2 O 2 S:Tb screens, under similar conditions (x-ray incident energy, screen thickness)

Digital radiography: description and user's guide

Energy Technology Data Exchange (ETDEWEB)

Berthel, A. [Cryospace, 78 - Les Mureaux (France); Bonin, Th. [CEA Valduc, 21 - Is-sur-Tille (France); Cadilhon, S.; Thiery, Ch. [CEA Bruyeres-le-Chatel, 91 (France); Chatellier, L. [Electricite de France (EDF-RD), Recherche et Developpement, 78 - Chatou (France); Kaftandjian, V. [Lyon Univ., INSA Lab. Controle Non Destructif par Rayonnements Ionisants (CNDRI), 69 (France); Honorat, Ph.; Torrent, J. [SNECMA, 75 - Paris (France); Le Brun, A. [Electricite de France, 78 - Chatou (France); Maglaive, J.C. [Euromev, 78 - Buc (France); Moreau, Ph. [General Electric Industrial Inspection Technologies, 69 - Limonest (France); Pettier, J.L. [CEA Cadarach, Dir. de l' Energie Nucleaire, 13 - Saint Paul lez Durance (France); Rebuffel, V. [CEA Grenoble, Lab. d' Electronique et de Technologie de l' Informatique (LETI), 38 (France); Roenelle, P. [Centre d' Etudes Techniques de l' Equipement, 69 - Bron Lyon (France); Roussilhe, J. [Carestream Health France SA, 71 - Chalon/Saone (France); Staat, St.; Tahon, M. [Cegelec, 91 - Bretigny sur Orge (France)

2007-07-01

The presented document arises from the work of the group 'Digital Radiography and sensors' of COFREND. It is a collective work of synthesis aimed to analyze the quality parameters of digital images influencing the answer and the diagnosis brought to a given industrial problem. Five families of digital sensors have been studied: 1. Image Intensifier coupled with CCD devices - 2. scintillators coupled with a CCD device- 3. Flat Panels with indirect conversion - 4. Flat Panels with direct electric conversion - 5. Photostimulable Storage Phosphor Screens). In particular, concerning a complete imaging chain, it deals with the notions of magnification, blur (unsharpness) (geometrical, kinetic or internal to the very sensor), noises, scattered radiation, spatial resolution, which is different from the one of analog detectors such as films, Contrast to Noise Ratio (CNR), sensitivity using IQIs, dynamic range, detection quantum efficiency, persistence and temporal resolution. This document is not a standard; it must be understood as a user's guide, and it approaches some essentials corrections to bring to a sensor in order to optimize his efficiency without losing information during the pre-processing phase in the radiographic acquisition. It also introduces some image processing tools commonly used. It can be used as a source document to the future elaboration of a standardisation document. It augurs not at all of the choice of a digital sensor with regard to the traditional radiographic film, but gives bases of reflection to a radio user for a sensible transfer from the classic radiography to the digital radiography. (authors)

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

International Nuclear Information System (INIS)

Calza, Cristiane; Oliveira, Davi F.; Rocha, Henrique S.; Lopes, Ricardo Tadeu

2009-01-01

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

Estimation of dose to patients undergoing computed radiography x-ray examinations in some Khartoum hospitals

International Nuclear Information System (INIS)

Badri, Fatima Abulgasiem Abdulrhman

2015-12-01

This study was designed to evaluate the entrance surface air kerma to the patient during x-ray examination to (chest PA, lumbar spine AP and Lat, pelvis AP) by using computed radiography (CR) in different three hospitals in Khartoum. Three x-ray machines were covered. A total of 135 patients were evaluated. The entrance surface air kerma was calculated for each patient from the exposure parameters using cal dose software version 3.5. The obtained results showed that, the entrance surface air kerma range founded to be (0.28-1.59) for chest PA, (1.98-2.62) for lumbar spine and (0.438-2.47) for pelvis AP. The higher entrance surface air kerma for all projections were observed in Center 1, except for pelvis it is higher in center 2. And the lower entrance surface air kerma were observed in center 3. This study recommends that CR operator must to be used to achieve optimize the patient dose by use the best strategies available for reducing radiation dose, computed radiography must be used with high level of training for medical staff to reduce the dose, each radiology department should implement a patient dose measurement quality assurance programme, doses to the patients should be regularly monitored and the proposed national DRLs should be taken as guidance for optimization.(Author)

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-07-01

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

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

Science.gov (United States)

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

Portable digital electronic radiography system

International Nuclear Information System (INIS)

Sawicka, B.D.

1995-01-01

Radiography is a standard nondestructive technique in the industrial testing of materials and components. It is routinely used during the construction, maintenance and repair of nuclear plants. Traditionally, radiography is performed using photographic film (film radiography, FR). Recent developments in solid-state area imaging radiation detectors, miniature electronics and computer software/hardware techniques have brought electronic alternatives to FR. In recent years various electronic radiography (ER) techniques have served as alternatives to FR, these proved beneficial in some applications. While originally developed to provide real time imaging, ER may offer other advantages over FR, depending on the application. Work was undertaken at CRL to review progress in ER techniques and evaluate the possibility of constructing a portable DER (digital electronic radiography) system, for the inspection of power plant components. A suitable DER technique has been developed and a proof of principle portable system constructed. As this paper demonstrates, a properly designed ER system can be small and compact, while providing radiographic examination with acceptable image quality and the benefits of ER imaging. The CRL DER system can operate with radioactive sources typical of FR. While it does not replace FR, our DER system is expected to be beneficial in specific applications for Candu maintenance, reducing cost, labour and time. Practical, cost saving applications of this system are expected to include valve monitoring and foreign object location during maintenance at Candu reactors

Peri-implant assessment via cone beam computed tomography and digital periapical radiography: an ex vivo study

Directory of Open Access Journals (Sweden)

Nicolau Silveira-Neto

Full Text Available OBJECTIVES: This research evaluated detail registration in peri-implant bone using two different cone beam computer tomography systems and a digital periapical radiograph. METHODS: Three different image acquisition protocols were established for each cone beam computer tomography apparatus, and three clinical situations were simulated in an ex vivo fresh pig mandible: buccal bone defect, peri-implant bone defect, and bone contact. Data were subjected to two analyses: quantitative and qualitative. The quantitative analyses involved a comparison of real specimen measures using a digital caliper in three regions of the preserved buccal bone – A, B and E (control group – to cone beam computer tomography images obtained with different protocols (kp1, kp2, kp3, ip1, ip2, and ip3. In the qualitative analyses, the ability to register peri-implant details via tomography and digital periapical radiography was verified, as indicated by twelve evaluators. Data were analyzed with ANOVA and Tukey’s test (α=0.05. RESULTS: The quantitative assessment showed means statistically equal to those of the control group under the following conditions: buccal bone defect B and E with kp1 and ip1, peri-implant bone defect E with kp2 and kp3, and bone contact A with kp1, kp2, kp3, and ip2. Qualitatively, only bone contacts were significantly different among the assessments, and the p3 results differed from the p1 and p2 results. The other results were statistically equivalent. CONCLUSIONS: The registration of peri-implant details was influenced by the image acquisition protocol, although metal artifacts were produced in all situations. The evaluators preferred the Kodak 9000 3D cone beam computer tomography in most cases. The evaluators identified buccal bone defects better with cone beam computer tomography and identified peri-implant bone defects better with digital periapical radiography.

Fundamentals of phosphors

CERN Document Server

Yen, William M; Yamamoto, Hajime

2006-01-01

Drawing from the second edition of the best-selling Handbook of Phosphors, Fundamentals of Phosphors covers the principles and mechanisms of luminescence in detail and surveys the primary phosphor materials as well as their optical properties. The book addresses cutting-edge developments in phosphor science and technology including oxynitride phosphors and the impact of lanthanide level location on phosphor performance.Beginning with an explanation of the physics underlying luminescence mechanisms in solids, the book goes on to interpret various luminescence phenomena in inorganic and organic materials. This includes the interpretation of the luminescence of recently developed low-dimensional systems, such as quantum wells and dots. The book also discusses the excitation mechanisms by cathode-ray and ionizing radiation and by electric fields to produce electroluminescence. The book classifies phosphor materials according to the type of luminescence centers employed or the class of host materials used and inte...

Accelerated H-LBP-based edge extraction method for digital radiography

Energy Technology Data Exchange (ETDEWEB)

Qiao, Shuang; Zhao, Chen-yi; Huang, Ji-peng [School of Physics, Northeast Normal University, Changchun 130024 (China); Sun, Jia-ning, E-mail: sunjn118@nenu.edu.cn [School of Mathematics and Statistics, Northeast Normal University, Changchun 130024 (China)

2015-01-11

With the goal of achieving real time and efficient edge extraction for digital radiography, an accelerated H-LBP-based edge extraction method (AH-LBP) is presented in this paper by improving the existing framework of local binary pattern with the H function (H-LBP). Since the proposed method avoids computationally expensive operations with no loss of quality, it possesses much lower computational complexity than H-LBP. Experimental results on real radiographies show desirable performance of our method. - Highlights: • An accelerated H-LBP method for edge extraction on digital radiography is proposed. • The novel AH-LBP relies on numerical analysis of the existing H-LBP method. • Aiming at accelerating, H-LBP is reformulated as a direct binary processing. • AH-LBP provides the same edge extraction result as H-LBP does. • AH-LBP has low computational complexity satisfying real time requirements.

Fully automatic and reference-marker-free image stitching method for full-spine and full-leg imaging with computed radiography

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Wang, Xiaohui; Foos, David H.; Doran, James; Rogers, Michael K.

2004-05-01

Full-leg and full-spine imaging with standard computed radiography (CR) systems requires several cassettes/storage phosphor screens to be placed in a staggered arrangement and exposed simultaneously to achieve an increased imaging area. A method has been developed that can automatically and accurately stitch the acquired sub-images without relying on any external reference markers. It can detect and correct the order, orientation, and overlap arrangement of the subimages for stitching. The automatic determination of the order, orientation, and overlap arrangement of the sub-images consists of (1) constructing a hypothesis list that includes all cassette/screen arrangements, (2) refining hypotheses based on a set of rules derived from imaging physics, (3) correlating each consecutive sub-image pair in each hypothesis and establishing an overall figure-of-merit, (4) selecting the hypothesis of maximum figure-of-merit. The stitching process requires the CR reader to over scan each CR screen so that the screen edges are completely visible in the acquired sub-images. The rotational displacement and vertical displacement between two consecutive sub-images are calculated by matching the orientation and location of the screen edge in the front image and its corresponding shadow in the back image. The horizontal displacement is estimated by maximizing the correlation function between the two image sections in the overlap region. Accordingly, the two images are stitched together. This process is repeated for the newly stitched composite image and the next consecutive sub-image until a full-image composite is created. The method has been evaluated in both phantom experiments and clinical studies. The standard deviation of image misregistration is below one image pixel.

Practical applications of phosphors

CERN Document Server

Yen, William M; Yamamoto, Hajime

2006-01-01

Drawn from the second edition of the best-selling Phosphor Handbook, Practical Applications of Phosphors outlines methods for the production of various phosphors and discusses a broad spectrum of applications. Beginning with methods for synthesis and related technologies, the book sets the stage by classifying and then explaining practical phosphors according to usage. It describes the operating principle and structure of phosphor devices and the phosphor characteristics required for a given device, then covers the manufacturing processes and characteristics of phosphors. The book discusses research and development currently under way on phosphors with potential for practical usage and touches briefly on phosphors that have played a historical role, but are no longer of practical use. It provides a comprehensive treatment of applications including lamps and cathode-ray tubes, x-ray and ionizing radiation, and for vacuum fluorescent and field emission displays and covers inorganic and organic electroluminescen...

Thermoluminescent phosphor

Science.gov (United States)

Lasky, Jerome B.; Moran, Paul R.

1978-01-01

A thermoluminescent phosphor comprising LiF doped with boron and magnesium is produced by diffusion of boron into a conventional LiF phosphor doped with magnesium. Where the boron dopant is made to penetrate only the outer layer of the phosphor, it can be used to detect shallowly penetrating radiation such as tritium beta rays in the presence of a background of more penetrating radiation.

Heavy-ion radiography and heavy-ion computed tomography

International Nuclear Information System (INIS)

Fabrikant, J.I.; Holley, W.R.; McFarland, E.W.; Tobias, C.a.

1982-02-01

Heavy-ion projection and CT radiography is being developed into a safe, low-dose, noninvasive radiological procedure that can quantitate and image small density differences in human tissues. The applications to heavy-ion mammography and heavy-ion CT imaging of the brain in clinical patients suggest their potential value in cancer diagnosis

Digital radiography and caries diagnosis.

Science.gov (United States)

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

Rare earth phosphors and phosphor screens

International Nuclear Information System (INIS)

Buchanan, R.A.; Maple, T.G.; Sklensky, A.F.

1981-01-01

Advances in the use of stabilized rare earth phosphors and of conversion screens using these materials are examined. In particular the new phosphors discussed in this invention consist of oxybromides of yttrium, lanthanum and gadolinium with a luminescent activator ion stabilized by an oxychloride or oxyfluoride surface layer and the conversion screens include trivalent cerium as the activator ion. (U.K.)

Initial quantitative evaluation of computed radiography in an intensive care unit

International Nuclear Information System (INIS)

Hillis, D.J.; McDonald, I.G.; Kelly, W.J.

1996-01-01

The first computed radiography (CR) unit in Australia was installed at St Vincent's Hospital, Melbourne, in February 1994. An initial qualitative evaluation of the attitude of the intensive care unit (ICU) physicians to the CR unit was conducted by use of a survey. The results of the survey of ICU physicians indicated that images were available faster than under the previous system and that the use of the CR system was preferred to evaluate chest tubes and line placements. While it is recognized that a further detailed radiological evaluation of the CR system is required to establish the diagnostic performance of CR compared with conventional film, some comments on the implementation of the system and ICU physician attitudes to the CR system are put forward for consideration by other hospitals examining the possible use of CR systems. 11 refs., 1 tab

Nuclear imaging using Fuji Computed Radiography

International Nuclear Information System (INIS)

Yodono, Hiraku; Tarusawa, Nobuko; Katto, Keiichi; Miyakawa, Takayoshi; Watanabe, Sadao; Shinozaki, Tatsuyo

1988-01-01

We studied the feasibility of the Fuji Computed Radiography system (FCR) in nuclear medicine. The basic principle of the system is the conversion of the X-ray energy pattern into digital signals utilizing scanning laser stimulated luminescence. A Rollo phantom filled with 12 mCi of Tc-99m pertechnetate was used in this study. In imaging by the FCR, a low energy high resolution parallel hole collimator for a gamma camera was placed over the phantom and photons through the collimator were stored on a single imaging plate (IP) or 3 IPs covered by the lead plate, 0.3 mm in thickness. For imaging, it took 30 minutes by a single IP and 20 minutes by 3 IPs with the lead plate respectively. Each image of the phantom by the FCR was compared with that of obtained by a gamma camera. The image by a single IP was inferior in quality than that of by a gamma camera. However using 3 IPs with the lead plate, same quality image as by a gamma camera was obtained. The image by 3 IPs is similar to that of by 3 IPs with the lead plate. Based on the results, we performed liver and lung imaging by FCR using 3 IPs. The imaging time is twenty minutes. The images obtained with FCR are as good as the scinticamera image. However it has two major flawes in that the sensitivity is poor and the imaging time is long. Furthermore, at present this method can only be employed for static imaging. However we feel that future improvements in the FCR system will overcome these problems. (author)

Comparative study on computed orthopantomography and film radiographic techniques in the radiography of temporomandibular joint

International Nuclear Information System (INIS)

Chen Tao; Ning Lixia; Liu Yuai; Li Ningyi; Chen Feng

2007-01-01

Objective: To compare the computed orthopantomography (COPT) with Shriller radiography(SR), film orthopantomography (FOPT) and other traditional radiographic techniques in the radiography of temporomandibular joint (TMJ). Methods: Ninty-eight cases were randomly divided into 3 groups, and the open and close positions of TMJs of both sides were examined with SR, FOPT, and COPT, respectively. The satisfactory rates of the X-ray pictures were statistically analyzed with Pearson chi-square in SPSS10.0, and the satisfactory rates were analyzed with q test between the groups. Results: One hundred and forty-four of the open and close positions of 144 TMJ pictures of the COPT group, 128 of 128 of the FOPT group, and 6 of 120 of the SR group were satisfactory in the mandible ramus of the TMJ, with satisfactory rate being 100%, 100%, and 5%, respectively (P 0.01), respectively between FOPT and COPT groups. The difference was not statistically significant. The exposure was as follows: COPT, 99-113 mAs; FOPT, 210-225 mAs; and SR, 48-75 mAs. Therefore, COPT and FOPT were superior to SR in the pictures of the mandible ramus, coronoid process, and incisure, but inferior in the joint space pictures. The satisfactory rates of the condylar process and articular tubercle were same in the 3 groups. The exposure of the FOPT group was greater than that of the COPT and SR groups. Conclusion: COPT is superior to SR and FOPT in TMJ radiography, and should be applied widely in the clinic. (authors)

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

International Nuclear Information System (INIS)

Rubio Rivero, A.; Caballero Pinelo, R.; Gonzalez Perez, Y.

2015-01-01

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

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

International Nuclear Information System (INIS)

Okamura, Kazutoshi; Tanaka, Takemasa; Yoshiura, Kazunori; Tokumori, Kenji; Kanda, Shigenobu

2002-01-01

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

[Conventional radiology, digital radiology with photostimulable phosphor, laser digitalization of thoracic radiographic films at the bedside. A comparative study].

Science.gov (United States)

Miceli, M; Stamati, R; Burci, P; Guidarelli, G; Sartoni Galloni, S

1992-10-01

The bedside chest images obtained with conventional radiology and with "on line" and "off line" digital modalities were compared to evaluate the respective capabilities in visualizing chest anatomical structures. Seventy patients were submitted to bedside chest examinations with a portable unit; both a conventional film and a digital system (PCR Graphics 1, Philips) with photostimulable phosphor imaging plate were fitted in the radiographic cassette. The former was digitized using an "off line" laser beam unit (FD 2000, Dupont); the latter was subsequently postprocessed by modifying contrast, optical density and spatial frequencies. Thus, 4 different viewing modalities were obtained for each examination: a) conventional radiography; b) standard digital radiography; c) postprocessed digital radiography; d) digitized conventional radiography. Detectability rates of chest anatomical structures were analyzed by 4 independent radiologists on the different images and expressed by a score 1-4. The values were always higher with digital modalities than with the conventional one and the differences were statistically significant (Student's t-test modified by Bonferroni). In particular, the greatest difference was found between c) and a) in retrocardiac lung parenchyma and in skeletal structures, in favour of c). Concerning the comparative adequacy of the various digital modalities, higher detectability rates of chest anatomical structures were obtained with c), but also with b), than with d).

Radiography

Science.gov (United States)

Gardner, C. G.

1973-01-01

Radiography is discussed as a method for nondestructive evaluation of internal flaws of solids. Gamma ray and X-ray equipment are described along with radiographic film, radiograph interpretation, and neutron radiography.

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

International Nuclear Information System (INIS)

Voorhout, G.; Stolp, R.; Rijnberk, A.; Waes, P.F.G.M. van

1990-01-01

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

Computed radiography utilizing laser-stimulated luminescence: detectability of simulated low-contrast radiographic objects.

Science.gov (United States)

Higashida, Y; Moribe, N; Hirata, Y; Morita, K; Doudanuki, S; Sonoda, Y; Katsuda, N; Hiai, Y; Misumi, W; Matsumoto, M

1988-01-01

Threshold contrasts of low-contrast objects with computed radiography (CR) images were compared with those of blue and green emitting screen-film systems by employing the 18-alternative forced choice (18-AFC) procedure. The dependence of the threshold contrast on the incident X-ray exposure and also the object size was studied. The results indicated that the threshold contrasts of CR system were comparable to those of blue and green screen-film systems and decreased with increasing object size, and increased with decreasing incident X-ray exposure. The increase in threshold contrasts was small when the relative incident exposure decreased from 1 to 1/4, and was large when incident exposure was decreased further.

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

Science.gov (United States)

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

2014-01-01

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

Proceedings of 7th short conference on neutron radiography

International Nuclear Information System (INIS)

Hiraoka, Eiichi; Katsurayama, Kousuke; Tsujimoto, Tadashi

1986-10-01

The first short period conference on neutron radiography was held in 1970, and now the 7th meeting was held. The works to develop neutron radiography in Japan are as active as those in western countries, and the research is in progress by using neutrons from reactors, radioisotopes and accelerators in order to achieve the technology of high standard. In this conference, 26 papers and six comments were presented, and the themes covered the equipment for radiography, the practical application, and the related research. The second World Conference on Neutron Radiography will be held in Paris in June, 1986, and the further promotion of the spread of neutron radiography can be expected. The proceedings of the conference is published with the hope that joint effort and information exchange are further enhanced in coming years to develop the neutron radiography in Japan. The neutron radiography using the Kinki University reactor, the Rikkyo Triga-2 reactor, the Musashi reactor, the Kyoto research reactor, a 3MV Van de Graaff accelerator in Toyota, a subcompact cyclotron in Sumitomo, a baby cyclotron-dual collimator in National Space Development Agency and so on, Cf-252 based thermal neutron radiography, CT with Sb-124/Be neutrons, pulse power neutron source, imaging converters, neutron radiographic image processing, computed tomography using neutron television systems and others are reported. (Kako, I.)

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

International Nuclear Information System (INIS)

Mustonen, A.O.T.; Kiuru, M.J.

2005-01-01

Purpose: To evaluate the multidetector computed tomography (MDCT) findings of acute knee trauma and to compare radiography with MDCT in patients referred ta level 1 trauma center. Material and Methods: During a 5-year period, a total of 415 MDCT examinations were performed on 409 patients with acute knee trauma to reveal complex fracture anatomy or rule out a fracture. MDCT and primary radiographs were re-evaluated with respect to fracture location and trauma mechanism. Tibial plateau fractures were further analyzed depending on anatomical location: anterior-medial, anterior-lateral, posterior-lateral, and posterior-medial regions. Maximal depression of the tibial articular surface was measured. Findings on the primary knee radiographs were compared with MDCT findings. Results: Of the 409 patients, 356 (87%) had a knee fracture. A total of 451 fractures were found in all anatomic regions: distal femur ( n = 49), proximal tibia ( n 307), patella ( n = 23), and proximal fibula ( n = 72). Primary radiographs were available in 316 (76%) cases. Of these, 225 (71%) had MDCT in order to reveal the fracture anatomy better, and 91 (29%) had a subsequent MDCT after negative plain radiographs. Overall sensitivity of radiography was 83%, while negative predictive value was 49%. On radiography, tibial plateau articular depression was underestimated in all regions except when the fracture consisted of the whole half of the anterior or posterior plateau. The three main injury mechanisms were traffic accident, a simple fall, and sport. In 49 cases (15%), primary radiographs were suboptimal due to positioning. Conclusion: In severely injured patients, diagnostically sufficient radiographs are difficult to obtain, and therefore a negative radiograph is not reliable in ruling out a fracture. In these patients, MDCT is a fast and accurate examination and is also recommended in patients with tibial plateau fractures or complex knee injuries in order to evaluate the fracture adequately

Apparatus for proton radiography

International Nuclear Information System (INIS)

Martin, R.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. 10 claims, 7 drawing figures

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

Science.gov (United States)

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 chest radiography for all nodules (1.49-fold, P chest radiography, as given by the area under the receiver operating characteristic curve (1.23-fold, P chest radiography or tomosynthesis. Conclusion Tomosynthesis outperformed conventional chest radiography for lung nodule detection and determination of case management; DE imaging did not show significant differences over conventional chest

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

International Nuclear Information System (INIS)

Rivetti, S.; Canossi, B.; Battista, R.; Vetruccio, E.; Torricelli, P.; Lanconelli, N.; Danielli, C.; Borasi, G.

2009-01-01

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

Receiver operating characteristic analysis of chest radiographs with computed radiography and conventional analog films

International Nuclear Information System (INIS)

Morioka, C.; Brown, K.; Dalter, S.; Milos, M.J.; Huang, H.K.; Kangarloo, H.; Boechat, I.M.; Batra, P.

1988-01-01

Receiver operating characteristic is used to compare the image quality of films obtained digitally using computed radiography (CR) and conventionally using analog film following fluoroscopic examination. Twenty-four cases, some with a solitary noncalcified nodule and/or pneumothorax, were collected. Ten radiologists have been tested viewing analog and CR digital films separately. Preliminary results indicate that there is no significant difference in the ability to detect either a pneumothorax or a solitary noncalcified nodule when comparing CR digital film with conventional analog film. A comparison of the CR digital image displayed on a 2,048-line monitor against analog and CR digital film is in progress

Radiography – How do students understand the concept of radiography?

International Nuclear Information System (INIS)

Lundgren, S.M.; Lundén, M.; Andersson, B.T.

2015-01-01

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

Flat-detector computed tomography in diagnostic and interventional neuroradiology

International Nuclear Information System (INIS)

Struffert, T.; Doerfler, A.

2009-01-01

Originally aimed at improving standard radiography by providing higher absorption efficiency and a wider dynamic range than available with film-screen and phosphor luminescence, radiography flat detector technology is now widely accepted for neuroangiographic imaging. Especially flat-detector computed tomography (FD-CT), which uses rotational C-arm mounted flat-panel detector technology, is capable of volumetric imaging with a high spatial resolution. As ''angiographic CT'' FD-CT may be helpful in many diagnostic and neurointerventional procedures, e.g. intracranial stenting for cerebrovascular stenoses, stent-assisted coil embolization of wide-necked cerebral aneurysms and embolization of arteriovenous malformations. By providing morphologic, CT-like images of the brain within the angiography suite FD-CT allows rapid visualization of periprocedural hemorrhaging and may thus improve rapid complication management without the need of patient transfer. In addition, myelography and postmyelographic FD-CT imaging can be carried out using a single modality. Spinal interventions, such as kyphoplasty or vertebroplasty might also benefit from FD-CT. Imaging of the temporal bone may also develop into an important field of FD-CT. This paper briefly reviews the technical principles of FD technology and the potential applications in diagnostic and interventional neuroradiology. (orig.) [de

Organ dose variability and trends in tomosynthesis and radiography.

Science.gov (United States)

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

2017-07-01

The purpose of this study was to investigate relationships between patient attributes and organ dose for a population of computational phantoms for 20 tomosynthesis and radiography protocols. Organ dose was estimated from 54 adult computational phantoms (age: 18 to 78 years, weight 52 to 117 kg) using a validated Monte-Carlo simulation (PENELOPE) of a system capable of performing tomosynthesis and radiography. The geometry and field of view for each exam were modeled to match clinical protocols. For each protocol, the energy deposited in each organ was estimated by the simulations, converted to dose units, and then normalized by exposure in air. Dose to radiosensitive organs was studied as a function of average patient thickness in the region of interest and as a function of body mass index. For tomosynthesis, organ doses were also studied as a function of x-ray tube position. This work developed comprehensive information for organ dose dependencies across a range of tomosynthesis and radiography protocols. The results showed a protocol-dependent exponential decrease with an increasing patient size. There was a variability in organ dose across the patient population, which should be incorporated in the metrology of organ dose. The results can be used to prospectively and retrospectively estimate organ dose for tomosynthesis and radiography.

Digital Radiography and Computed Tomography (DRCT) Product Improvement Plan (PIP)

Energy Technology Data Exchange (ETDEWEB)

Tim Roney; Bob Pink; Karen Wendt; Robert Seifert; Mike Smith

2010-12-01

The Idaho National Laboratory (INL) has been developing and deploying x-ray inspection systems for chemical weapons containers for the past 12 years under the direction of the Project Manager for Non-Stockpile Chemical Materiel (PMNSCM). In FY-10 funding was provided to advance the capabilities of these systems through the DRCT (Digital Radiography and Computed Tomography) Product Improvement Plan (PIP), funded by the PMNSCM. The DRCT PIP identified three research tasks; end user study, detector evaluation and DRCT/PINS integration. Work commenced in February, 2010. Due to the late start and the schedule for field inspection of munitions at various sites, it was not possible to spend sufficient field time with operators to develop a complete end user study. We were able to interact with several operators, principally Mr. Mike Rowan who provided substantial useful input through several discussions and development of a set of field notes from the Pueblo, CO field mission. We will be pursuing ongoing interactions with field personnel as opportunities arise in FY-11.

Computed radiography systems performance evaluation;Avaliacao de desempenho de sistemas de radiografia computadorizada

Energy Technology Data Exchange (ETDEWEB)

Xavier, Clarice C.; Nersissian, Denise Y.; Furquim, Tania A.C. [Universidade de Sao Paulo (IEE/USP), SP (Brazil). Inst. de Eletrotecnica e Energia

2009-07-01

The performance of a computed radiography system was evaluated, according to the AAPM Report No. 93. Evaluation tests proposed by the publication were performed, and the following nonconformities were found: imaging p/ate (lP) dark noise, which compromises the clinical image acquired using the IP; exposure indicator uncalibrated, which can cause underexposure to the IP; nonlinearity of the system response, which causes overexposure; resolution limit under the declared by the manufacturer and erasure thoroughness uncalibrated, impairing structures visualization; Moire pattern visualized at the grid response, and IP Throughput over the specified by the manufacturer. These non-conformities indicate that digital imaging systems' lack of calibration can cause an increase in dose in order that image prob/ems can be so/ved. (author)

Phosphorous vacancy nearest neighbor hopping induced instabilities in InP capacitors II. Computer simulation

International Nuclear Information System (INIS)

Juang, M.T.; Wager, J.F.; Van Vechten, J.A.

1988-01-01

Drain current drift in InP metal insulator semiconductor devices display distinct activation energies and pre-exponential factors. The authors have given evidence that these result from two physical mechanisms: thermionic tunneling of electrons into native oxide traps and phosphorous vacancy nearest neighbor hopping (PVNNH). They here present a computer simulation of the effect of the PVNHH mechanism on flatband voltage shift vs. bias stress time measurements. The simulation is based on an analysis of the kinetics of the PVNNH defect reaction sequence in which the electron concentration in the channel is related to the applied bias by a solution of the Poisson equation. The simulation demonstrates quantitatively that the temperature dependence of the flatband shift is associated with PVNNH for temperatures above room temperature

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

International Nuclear Information System (INIS)

Einarsdóttir, Hildur; Larsen, Rasmus; Ersbøll, Bjarne Kjær; Yaroshenko, Andre; Velroyen, Astrid; Bech, Martin; Pfeiffer, Franz; Hellbach, Katharina; Auweter, Sigrid; Meinel, Felix G; Reiser, Maximilian; Yildirim, Önder; Eickelberg, Oliver

2015-01-01

In this work we develop a computer-aided diagnosis (CAD) scheme for classification of pulmonary disease for grating-based x-ray radiography. In addition to conventional transmission radiography, the grating-based technique provides a dark-field imaging modality, which utilizes the scattering properties of the x-rays. This modality has shown great potential for diagnosing early stage emphysema and fibrosis in mouse lungs in vivo. The CAD scheme is developed to assist radiologists and other medical experts to develop new diagnostic methods when evaluating grating-based images. The scheme consists of three stages: (i) automatic lung segmentation; (ii) feature extraction from lung shape and dark-field image intensities; (iii) classification between healthy, emphysema and fibrosis lungs. A study of 102 mice was conducted with 34 healthy, 52 emphysema and 16 fibrosis subjects. Each image was manually annotated to build an experimental dataset. System performance was assessed by: (i) determining the quality of the segmentations; (ii) validating emphysema and fibrosis recognition by a linear support vector machine using leave-one-out cross-validation. In terms of segmentation quality, we obtained an overlap percentage (Ω) 92.63  ±  3.65%, Dice Similarity Coefficient (DSC) 89.74  ±  8.84% and Jaccard Similarity Coefficient 82.39  ±  12.62%. For classification, the accuracy, sensitivity and specificity of diseased lung recognition was 100%. Classification between emphysema and fibrosis resulted in an accuracy of 93%, whilst the sensitivity was 94% and specificity 88%. In addition to the automatic classification of lungs, deviation maps created by the CAD scheme provide a visual aid for medical experts to further assess the severity of pulmonary disease in the lung, and highlights regions affected. (paper)

Investigation of physical imaging properties in various digital radiography systems

Energy Technology Data Exchange (ETDEWEB)

Jeong, Hoi Woun [Dept. of Radiological Science, Baekseok Culture University, Cheonan (Korea, Republic of); Min, Jung Hwan [Dept. of Radiological technology, Shingu University, Seongnam (Korea, Republic of); Yoon, Yong Su [Dept. of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Kyushu (Japan); Kim, Jung Min [Dept. of Health and Environmental Science, College of Health Science, Korea University, Seoul (Korea, Republic of)

2017-09-15

We aimed to evaluate the physical imaging properties in various digital radiography systems with charged coupled device (CCD), computed radiography (CR), and indirect flat panel detector (FPD). The imaging properties measured in this study were modulation transfer function (MTF) wiener spectrum (WS), and detective quantum efficiency (DQE) to compare the performance of each digital radiography system. The system response of CCD were in a linear relationship with exposure and that of CR and FPD were proportional to the logarithm of exposure. The MTF of both CR and FPD indicated a similar tendency but in case of CCD, it showed lower MTF than that of CR and FPD. FPD showed the lowest WS and also indicated the highest DQE among three systems. According to the results, digital radiography system with different type of image receptor had its own image characteristics. Therefore, it is important to know the physical imaging characteristics of the digital radiography system accurately to obtain proper image quality.

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

Energy Technology Data Exchange (ETDEWEB)

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

2002-08-01

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

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

Science.gov (United States)

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

2002-08-01

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

Oxidizer in phosphoric reactors

International Nuclear Information System (INIS)

Santos Benedetto, J. dos

1985-01-01

Oxidation during the manufacture of wet-process phosphoric acid affected the distribution of uranium and impurities between phosphoric acid and gypsum, by decreasing the uranium loss to gypsum and the impurities solubilization in phosphoric acid. (Author) [pt

Evidence-based radiography

International Nuclear Information System (INIS)

Hafslund, Bjorg; Clare, Judith; Graverholt, Birgitte; Wammen Nortvedt, Monica

2008-01-01

Evidence-based practice (EBP) offers the integration of the best research evidence with clinical knowledge and expertise and patient values. EBP is a well known term in health care. This paper discusses the implementation of EBP into radiography and introduces the term evidence-based radiography. Evidence-based radiography is radiography informed and based on the combination of clinical expertise and the best available research-based evidence, patient preferences and resources available. In Norway, EBP in radiography is being debated and radiographers are discussing the challenges of implementing EBP in both academic and clinical practice. This discussion paper explains why EBP needs to be a basis for a radiography curriculum and a part of radiographers' practice. We argue that Norwegian radiographers must increase participation in research and developing practice within their specific radiographic domain

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

International Nuclear Information System (INIS)

Shida, T.; Suganuma, T.; Hashizume, T.

1984-01-01

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

Phosphors for LED lamps

Science.gov (United States)

Murphy, James Edward; Manepalli, Satya Kishore; Kumar, Prasanth Nammalwar

2013-08-13

A phosphor, a phosphor blend including the phosphor, a phosphor prepared by a process, and a lighting apparatus including the phosphor blend are disclosed. The phosphor has the formula (Ca.sub.1-p-qCe.sub.pK.sub.q).sub.xSc.sub.y(Si.sub.1-rGa.sub.r).sub.zO.su- b.12+.delta. or derived from a process followed using disclosed amounts of reactants. In the formula, (0

Phosphor scintillator structure

International Nuclear Information System (INIS)

Cusano, D.A.; Prener, J.S.

1980-01-01

A method of fabricating scintillators is described in which the phosphor is distributed within the structure in such a way as to enhance the escape of the visible wavelength radiation that would otherwise be dissipated within the scintillator body. Two embodiments of the present invention are disclosed: one in which the phosphor is distributed in a layered structure and another in which the phosphor is dispersed throughout a transparent matrix. (U.K.)

Evaluation of the map accuracy thickness defects by computer analysis of the radiography images

International Nuclear Information System (INIS)

Wawszczak, J.; Wocial, A.

2000-01-01

Analysis of the sensitivity map radiography for the local profiles of the surface steel plate with artificial of the thickness defects were presented of the paper. Errors of these method estimation and they sources were presented also. Usefulness of this mapping radiography during field investigations for paper and film carriers were discussed and concluded. (author)

Post-operative observation of ilio-apophyseal transplants on the basis of radiography, computed tomography, autoradiography and histological assessment

International Nuclear Information System (INIS)

Klatt, U.

1987-01-01

A study in 25 rabbits, in which the acetabular roof was reinforced by inserting a wedge-shaped autologous tissue fragment of the apophysis, led to the following conclusions: That complete healing and ossification of the implant took place within the observation period; that radiography, computed tomography, autoradiography and histology consistently provided evidence in confirmation of ossification; that a wedge-shaped fragment of apophyseal cartilage is a suitable material for plastic surgery in the acetabular roof. (TRV) [de

Large-image intensifier photofluorography and conventional radiography in pulmonary emphysema

International Nuclear Information System (INIS)

Manninen, H.; Partanen, K.; Soimakallio, S.; Rytkoenen, H.

1988-01-01

Large-screen image intensifier (II) photofluorography was compared with full-size screen-film chest radiography in the diagnosis of pulmonary emphysema in 84 patients. Photospot films and conventional radiographs were interpreted independently by three radiologists. Computed tomography (CT) was used as an independent reference technique, and diagnostic performance of chest radiography in various CT patterns of emphysema was evaluated. The difference in diagnostic sensitivity for emphysema in favor of conventional chest radiography over photofluorography (0.65 versus 0.56) was statistically significant (p < 0.05). Specificity of the imaging modalities was equal: 0.78 in full-size films and 0.77 in photospot films. All CT patterns of emphysema had great false negative response rates in chest radiography, which is an inaccurate technique for the diagnosis of emphysema. CT is required for reliable radiologic evaluation of emphysema. (orig.)

Digital radiography detectors - A technical overview: Part 1

International Nuclear Information System (INIS)

Lanca, Luis; Silva, Augusto

2009-01-01

During the last two decades screen-film (SF) systems have been replaced by digital X-ray systems. The advent of digital technologies brought a number of digital solutions based on different detector and readout technologies. Improvements in technology allowed the development of new digital technologies for projection radiography such as computed radiography (CR) and digital radiography (DR). The large number of scientific papers concerning digital X-ray systems that have been published over the last 25 years indicates the relevance of these technologies in healthcare. There are important differences among different detector technologies that may affect system performance and image quality for diagnostic purposes. Radiographers are expected to have an effective understanding of digital X-ray technologies and a high level of knowledge and awareness concerning the capabilities of these systems. Patient safety and reliable diagnostic information are intrinsically linked to these factors. In this review article - which is the first of two parts - a global overview of the digital radiography systems (both CR and DR) currently available for clinical practice is provided

[Digital thoracic radiology: devices, image processing, limits].

Science.gov (United States)

Frija, J; de Géry, S; Lallouet, F; Guermazi, A; Zagdanski, A M; De Kerviler, E

2001-09-01

In a first part, the different techniques of digital thoracic radiography are described. Since computed radiography with phosphore plates are the most commercialized it is more emphasized. But the other detectors are also described, as the drum coated with selenium and the direct digital radiography with selenium detectors. The other detectors are also studied in particular indirect flat panels detectors and the system with four high resolution CCD cameras. In a second step the most important image processing are discussed: the gradation curves, the unsharp mask processing, the system MUSICA, the dynamic range compression or reduction, the soustraction with dual energy. In the last part the advantages and the drawbacks of computed thoracic radiography are emphasized. The most important are the almost constant good quality of the pictures and the possibilities of image processing.

Measurements of Wiener spectra of laser printer in a computed radiography

International Nuclear Information System (INIS)

Yamauchi, Syuichi; Ueda, Katsuhiko; Nishihara, Sadamitsu; Ohtsuka, Akiyoshi; Fujita, Hiroshi; Morishita, Junji; Fujikawa, Tsuyoshi.

1992-01-01

Sources of noise in a computed radiography (CR) were investigated by measuring three different Wiener spectra: 1) laser printer Wiener spectra including CR film, 2) Wiener spectrum of CR film (single emulsion), and 3) overall Wiener spectra. To measure the noise contributed by the laser printer, 'image data' (i.e., image having a constant pixel value) were produced on a personal computer and were sent to the laser printer in the CR system. The noise level of laser printer was comparable to that of the CR film at low spatial frequencies ( 4 cycle/mm) was higher than that of the film. Laser printer Wiener spectra obtained in the perpendicular direction relative to the laser beam scanning direction were comparable at low spatial frequencies, but greater at high spatial frequencies, to those obtained in the parallel direction. And a spectral peak around 10 cycle/mm was obtained in the Wiener spectrum in the perpendicular direction. The peak is caused mainly by a banding artifact. Overall Wiener spectra in the parallel and perpendicular directions show the same tendency as those of the laser printer, but the noise level of the overall Wiener spectrum was increased mainly by X-ray quantum mottle at low spatial frequencies. In conclusion, the noise of laser printer greatly increases the overall Wiener spectrum at high spatial frequencies. (author)

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

International Nuclear Information System (INIS)

Uzum, Kazim; Karahan, Okkes I.; Dogan, Sukru; Coskun, Abdulhakim; Topcu, Faik

2003-01-01

Objective: The chest radiography and TCT findings in children who had contacted with adult family members with active pulmonary tuberculosis were compared. The contributions of thoracic computed tomography to the diagnosis of tuberculosis were investigated. Methods and material: The children who were 0-16 years old (n=173) and children of families with an adult member which was diagnosed as pulmonary tuberculosis were evaluated. The children were considered in two groups based on the absence (n=125) or presence (n=48) of complaints and/or ambiguous symptoms such as lack of appetite, mild cough, sweating, history of lung infection, low body weight and those with suspicious chest radiography findings (12 cases) were included in this study. Asymptomatic patients (n=125) did not undergo TCT. Patients who had positive PPD skin tests only received isoniazid. If the TCT demonstrated enlarged lymph nodes or parenchymal lesions, minimally active pulmonary tuberculosis was diagnosed and antituberculous treatment was given. Results and discussions: TCT revealed lymph node enlargement or parenchymal lesions in 39 children (81.2%). Of the 12 children whose CXRs revealed suspicious lymph node enlargement and/or infiltration, five had normal findings in TCT whereas the initial findings were confirmed in the remaining seven. These data suggest that there is a correlation between the presence of ambiguous symptoms in exposed children and TCT findings; chest radiography and TCT findings do not yield parallel findings. All the patients who received anti-TB treatment were resolved in the control examinations. Conclusion: In this study there is a correlation between presence of ambiguous symptoms and TCT findings, but the chest radiography and TCT findings do not yield harmony in exposed children with ambiguous symptoms (suspicious tuberculosis cases). These observations should be considered in children with symptoms similar to those of exposed children, but with no definite history of

Effect of exposure time reduction towards sensitivity and SNR for computed radiography (CR) application in NDT

International Nuclear Information System (INIS)

Sapizah Rahim; Khairul Anuar Mohd Salleh; Noorhazleena Azaman; Shaharudin Sayuti; Siti Madiha Muhammad Amir; Arshad Yassin; Abdul Razak Hamzah

2010-01-01

Signal-to-noise ratio (SNR) and sensitivity study of Computed Radiography (CR) system with reduction of exposure time is presented. The purposes of this research are to determine the behavior of SNR toward three different thicknesses (step wedge; 5, 10 and 15 mm) and the ability of CR system to recognize hole type penetrameter when the exposure time decreased up to 80 % according to the exposure chart (D7; ISOVOLT Titan E). It is shown that the SNR is decreased with decreasing of exposure time percentage but the high quality image is achieved until 80 % reduction of exposure time. (author)

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

Directory of Open Access Journals (Sweden)

Wilton Mitsunari Takeshita

2014-01-01

Full Text Available Background: To evaluate the diagnostic accuracy of different radiographic methods in the assessment of proximal alveolar bone loss (ABL. Materials and Methods: ABL, the distance between cement-enamel junction and alveolar bone crest, was measured in 70 mandibular human teeth - directly on the mandibles (control, using conventional periapical radiography with film holders (Rinn XCP and Han-Shin, digital periapical radiography with complementary metal-oxide semiconductor sensor, conventional panoramic, and cone-beam computed tomography (CBCT. Three programs were used to measure ABL on the images: Image tool 3.0 (University of Texas Health Sciences Center, San Antonio, Texas, USA, Kodak Imaging 6.1 (Kodak Dental Imaging 6.1, Carestream Health ® , Rochester, NY, USA, and i-CAT vision 1.6.20. Statistical analysis used ANOVA and Tukey′s test at 5% significance level. Results: The tomographic images showed the highest means, whereas the lowest were found for periapical with Han-Shin. Controls differed from periapical with Han-Shin (P < 0.0001. CBCT differed from panoramic (P = 0.0130, periapical with Rinn XCP (P = 0.0066, periapical with Han-Shin (P < 0.0001, and digital periapical (P = 0.0027. Conventional periapicals with film holders differed from each other (P = 0.0007. Digital periapical differed from conventional periapical with Han-Shin (P = 0.0004. Conclusions: Conventional periapical with Han-Shin film holder was the only method that differed from the controls. CBCT had the closest means to the controls.

Digital luminescent radiography: A substitute for conventional chest radiography?

International Nuclear Information System (INIS)

Neufang, K.F.R.; Krug, B.; Lorenz, R.; Steinbrich, W.

1990-01-01

The image quality of digital luminescent radiography (DLR) is sufficient for routine biplane chest radiography and for follow-up studies of heart size, pulmonary congestion, coin lesions, infiltrations, atelectasis, pleural effusions, and mediastinal and hilar lymph node enlargement. Chest radiography in the intensive care unit may in most cases be performed using the DLR technique. there is no need for repeat shots because of incorrect exposure, and the position of catheters, tubes, pacemakers, drains and artificial heart valves, the mediastinum, and the retrocardiac areas of the left lung are more confidently assessed on the edge-enhanced DLR films than on conventional films. Nevertheless, DLR is somewhat inferior to conventional film-screen radiography of the chest as it can demonstrate or rule out subtle pulmonary interstitial disease less confidently. There is no reduction of radiation exposure of the chest in DLR compared with modern film-screen systems. As a consequence, DLR is presently not in a position to replace traditional film-screen radiography of the chest completely. (orig.) [de

Electron-beam-pumped phosphors

International Nuclear Information System (INIS)

Goldhar, J.; Krupke, W.F.

1985-01-01

Electron-beam excitation of solid-state scintillators, or phosphors, can result in efficient generation of visible light confined to relatively narrow regions of the spectrum. The conversion efficiency can exceed 20%, and, with proper choice of phosphors, radiation can be obtained anywhere from the near infrared (IR) to the near ultraviolet (UV). These properties qualify the phosphors as a potentially useful pump source for new solid-state lasers. New phosphors are being developed for high-brightness television tubes that are capable of higher power dissipation. Here, an epitaxial film of fluorescing material is grown on a crystalline substrate with good thermal properties. For example, researchers at North American Philips Laboratories have developed a cerium-doped yttrium aluminum garnet (YAG) grown on a YAG substrate, which has operated at 1 A/cm 2 at 20 kV without observed thermal quenching. The input power is higher by almost two orders of magnitude than that which can be tolerated by a conventional television phosphor. The authors describe tests of these new phosphors

High temperature thermometric phosphors

Science.gov (United States)

Allison, Stephen W.; Cates, Michael R.; Boatner, Lynn A.; Gillies, George T.

1999-03-23

A high temperature phosphor consists essentially of a material having the general formula LuPO.sub.4 :Dy.sub.(x),Eu.sub.y) wherein: 0.1 wt %.ltoreq.x.ltoreq.20 wt % and 0.1 wt %.ltoreq.y.ltoreq.20 wt %. The high temperature phosphor is in contact with an article whose temperature is to be determined. The article having the phosphor in contact with it is placed in the environment for which the temperature of the article is to be determined. The phosphor is excited by a laser causing the phosphor to fluoresce. The emission from the phosphor is optically focused into a beam-splitting mirror which separates the emission into two separate emissions, the emission caused by the dysprosium dopant and the emission caused by the europium dopent. The separated emissions are optically filtered and the intensities of the emission are detected and measured. The ratio of the intensity of each emission is determined and the temperature of the article is calculated from the ratio of the intensities of the separate emissions.

RADIOGRAPHY IN THE FIELD: ASSESSING A LIGHTWEIGHT, HANDHELD, BATTERY-POWERED DENTISTRY UNIT FOR FIELD DIAGNOSTIC APPLICATIONS.

Science.gov (United States)

Seilern-Moy, Katharina; Vielgrader, Hanna; Gerritsmann, Hanno; Walzer, Chris

2017-03-01

Radiography units are not used commonly in wildlife medicine field settings, primarily because of their weight and requirement for a power supply. In this study, a portable, battery-powered, and lightweight radiography unit, originally developed for dentistry, was assessed for its potential field applications. Radiographs of various animal species (ranging in weight from 14 g to 1,000 kg) were imaged using varying source image distance (SID) and exposure time. The quality of these images was evaluated for their resolution, image noise, and motion blur. When required, image resolutions were further enhanced using computed radiography postprocessing. Other parameters evaluated were the freehand use of the device, its battery durability, the maximum obtainable image size, and multiple use of a single computed radiography cassette. Using an SID of 60 cm, radiographs delivered adequate image quality. The quality, however, was found deteriorated in images of larger animals (>50 kg) or thicker tissues (>15 cm). The use of a tripod proved unnecessary in most cases, and its exclusion greatly facilitated equipment handling. Under field conditions, the battery was depleted after a total running time of 1.6 hr or 36 radiographs. The maximum size of a radiographic image reached a diameter of 40 cm, and radiation shielding allowed the multiple use of a single computed radiography cassette. Taken together, the radiography unit evaluated in this study presented a balanced compromise between portability and radiograph quality for field use. However, the unit image resolution cannot replace those of the fixed standard radiography units commonly used in veterinary medicine.

Evaluation of organ dose and estimation of risk due to the abdominal region radiography in Indian adults

International Nuclear Information System (INIS)

Kumaresan, M.; Chaubey, Ajay; Kantharia, Surita; Karira, V.; Kumar, Rajesh; Biju, K.; Rao, B.S.

2006-01-01

Organ dose, risk of carcinogenesis and genetic effect due to the abdominal region radiography in Indian adult with the help of Monte-Carlo MCNP code by measuring the entrance skin dose by LiF: Mg, Cu, P TL phosphor and the risk coefficients provided by ICRP 60 were estimated. The entrance skin dose for abdominal region radiography was ranges from 2.75 mSv to 18.88 mSv while average entrance skin dose was 8.3 mSv. The bladder, testes and ovary are the important organ those are getting higher dose. The maximum dose for testes, ovary and bladder is 5.37 mSv, 1.45 mSv and 4.74 mSv respectively. The frequency of occurrence of fatal cancers and serious genetic disorders as a consequence of abdominal region radiography ranges from 0.1 to 38.8 risk/10 6 of fatal cancer. Although the estimated risks are small but cannot be neglected. It is important to avoid unnecessary repetitions and also to carry out proper quality assurance tests on the equipment and in the long run it will help reduce the risks and maximize the benefits of radiodiagnosis. These studies may lead to setting up of national reference levels for the diagnostic procedures India. (author)

Accuracy of Digital Radiography and Cone Beam Computed Tomography on Periapical Radiolucency Detection in Endodontically Treated Teeth

Directory of Open Access Journals (Sweden)

Tadas Venskutonis

2014-07-01

Full Text Available Objectives: The aim of the present study was to compare the accuracy of intraoral digital periapical radiography and cone beam computed tomography in the detection of periapical radiolucencies in endodontically treated teeth. Material and Methods: Radiographic images (cone beam computed tomography [CBCT] scans and digital periapical radiography [PR] images from 60 patients, achieved from September 2008 to July 2013, were retrieved from databases of the Department of Oral Diseases, Lithuanian University of Health Sciences. Twenty patients met inclusion criteria and were selected for further evaluation. Results: In 20 patients (42.4 [SD 12.1] years, 65% men and 35% women a total of 35 endodontically treated teeth (1.75 [SD 0.91]; 27 in maxilla and 8 in mandible were evaluated. Overall, it was observed a statistical significant difference between the number of periapical lesions observed in the CBCT (n = 42 and radiographic (n = 24 examinations (P < 0.05. In molar teeth, CBCT identify a significantly higher amount of periapical lesions than with the radiographic method (P < 0.05. There were significant differences between CBCT and PR in the mean number of lesions identified per tooth (1.2 vs 0.66, P = 0.03, number of teeth with lesions (0.71 vs 0.46, P = 0.03 and number of lesions identified per canal (0.57 vs 0.33, P = 0.005. Considering CBCT as “gold standard” in lesion detection with the sensitivity, specificity and accuracy considering as score 1, then the same parameters of PR were 0.57, 1 and 0.76 respectively. Conclusions: Within the limitations of the present study, it can be concluded that cone beam computed tomography scans were more accurate compared to digital periapical radiographs for detecting periapical radiolucencies in endodontically treated teeth. The difference was more pronounced in molar teeth.

Charged Particle Radiography

International Nuclear Information System (INIS)

Morris, Chris

2004-01-01

The Coulomb multiple scattering of charged particles as they pass through material allows them to be used as a radiographic probe. This forms the basis for a new kind of radiography that is finding application where conventional x-ray radiography is limited by flux or backgrounds. Charged-particle radiography is providing a versatile new probe that has advantages over conventional x-ray radiography for some unique application. Proton radiography has been used to make quantitative motion pictures of high explosive driven experiments and proves to be of great value for radiographing experiments that mock up nuclear weapon primaries for stockpile certification. By taking advantage of magnetic lens to magnify images and by using the very bright beams that can be made with electrons, charged-particle radiography may be useful for studying the fine spatial detail and very fast motion in laser driven implosion experiments at the National Ignition Facility. Finally, radiographs can be made using cosmic-ray muons for searching vehicles and cargo containers for surreptitious cargo of high z materials such as uranium or plutonium.

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

Directory of Open Access Journals (Sweden)

Muhogora Wilbroad

2011-01-01

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

Industrial radiography

International Nuclear Information System (INIS)

1992-01-01

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

Diagnostic Accuracy of Cone-beam Computed Tomography and Conventional Radiography on Apical Periodontitis: A Systematic Review and Meta-analysis.

Science.gov (United States)

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.

A Comparison of Angular Values of the Pelvic Limb with Normal and Medial Patellar Luxation Stifles in Chihuahua Dogs Using Radiography and Computed Tomography.

Science.gov (United States)

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  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.

Digital radiography: study of an alternative technique to conventional radiography

International Nuclear Information System (INIS)

Banchet, J.; Tisseur, D.; Thomas, A.

2009-01-01

Digital radiography, already in use in many industrial applications, appears as a potential alternative technique to conventional radiography in the nuclear field (and more especially to the inspection of welded joints). The advantages of digital radiography are a reduced explosion risk (due to the use of lower energy and activity sources), a lower installation time, a reduced exclusion zone, and the absence of effluents. However, to the contrary of the US case, this technique may not be used in France as it is not referenced in the regulating codes (RCCM, etc.). Areva has launched a R and D study in order to characterize the equivalencies between digital and conventional radiography. First results of this study are given

High-resolution computed tomography versus chest radiography in the diagnosis of interstitial lung disease in systemic sclerosis

International Nuclear Information System (INIS)

Azevedo, Ana Beatriz Cordeiro de; Calderaro, Debora; Moreira, Caio; Guimaraes, Silvana Mangeon Meirelles; Tavares Junior, Wilson Campos; Leao Filho, Hilton Muniz; Andrade, Diego Correa de; Ferreira, Cid Sergio; Vieira, Jose Nelson Mendes

2005-01-01

Objective: To compare the accuracy of high-resolution computed tomography (HRCT) with chest radiography in the diagnosis of interstitial lung disease in systemic sclerosis (SSc). Materials And Methods: HRCT scans and chest radiographs in postero-anterior and lateral views were performed in 34 patients with systemic sclerosis, according to the American College of Rheumatology preliminary criteria for the diagnosis of SSc. The prevalence of radiological findings suggestive of interstitial lung disease in SSc seen on both imaging methods was compared. Results: Interstitial disease was observed on HRCT images of 31 patients (91%) and in the chest radiographs of 16 patients (47%). The most frequent findings observed on HRCT were septal lines (74%), honeycombing (56%) and parenchymal bands (26%). Chest radiographs showed reticular areas of attenuation in 11 patients (32%) and parenchymal distortion in 12% of the patients. In 18 patients (53%) with normal chest radiographs HRCT showed septal lines in 55%, ground glass in 44%, honeycombing in 38.5% and cysts in 33%. Conclusion: HRCT is more sensitive than chest radiography in the evaluation of incipient interstitial lung involvement in patients with SSc and can provide a justification for immunosuppressive therapy in patients with early disease. (author)

Feasibility study of gamma-ray medical radiography

International Nuclear Information System (INIS)

Alyassin, Abdalmajeid M.; Maqsoud, Hamza A.; Mashat, Ahmad M.; Al-Mohr, Al-Sayed; Abdulwajid, Subhan

2013-01-01

This research explores the feasibility of using gamma-ray radiography in medical imaging. We will show that gamma-ray medical radiography has the potential to provide alternative diagnostic medical information to X-ray radiography. Approximately one Ci Am-241 radioactive source which emits mono-energetic 59.5 keV gamma rays was used. Several factors that influence the feasibility of this study were tested. They were the radiation source uniformity, image uniformity, and image quality parameters such as contrast, noise, and spatial resolution. In addition, several gamma-ray and X-ray images were acquired using humanoid phantoms. These images were recorded on computed radiography image receptors and displayed on a standard monitor. Visual assessments of these images were then conducted. The Am-241 radioactive source provided relatively uniform radiation exposure and images. Image noise and image contrast were mainly dependent on the exposure time and source size, whereas spatial resolution was dependent on source size and magnification factor. The gamma-ray humanoid phantom images were of lower quality than the X-ray images mainly due to the low radioactivity used and not enough exposure time. Nevertheless, the gamma-ray images displayed most of the main structures contained in the humanoid phantoms. Higher exposure rates and thus lower exposure times were estimated for different pure Am-241 source sizes that are hypothesized to provide high quality images similar to X-ray images. For instance, a 10 mm source size of pure Am-241 with 7 s exposure time should produce images similar in contrast and noise to X-ray images. This research paves the way for the production and usage of a highly radioactive Am-241 source with the potential to lead to the feasibility of acceptable quality medical gamma-ray radiography. - Highlights: ► Characterized the performance of gamma-ray radiography. ► Displayed medical images of humanoid phantoms using gamma radiography. ► Am-241

Neutron radiography, techniques and applications

International Nuclear Information System (INIS)

Domanus, J.C.

1987-10-01

After describing the principles of the ''in pool'' and ''dry'' installations, techniques used in neutron radiography are reviewed. Use of converter foils with silver halide films for the direct and transfer methods is described. Advantages of the use of nitrocellulose film for radiographying radioactive objects are discussed. Dynamic imaging is shortly reviewed. Standardization in the field of neutron radiography (ASTM and Euratom Neutron Radiography Working Group) is described. The paper reviews main fields of use of neutron radiography. Possibilities of use of neutron radiography at research reactors in various scientific, industrial and other fields are mentioned. Examples are given of application of neutron radiography in industry and the nuclear field. (author)

Basic principles of industrial radiography

International Nuclear Information System (INIS)

Bestbier, P.

1983-01-01

X-ray radiography and gamma radiography are used in industrial radiography. X-rays and gamma rays have the ability to penetrate materials and be absorbed by different densities. This characteristic makes them useful tools in industrial and medical radiography. The sources used for the generation of x-rays, gamma rays and radioisotopes are discussed. Films are one of the recording methods of x-radiography. The article also deals with advantages and disadvantages of radiography. Factors governing radiation exposure includes: the type of radiation source, material to be radiographed, distance, film, and the method for development. International specifications are also responsible for strict control over the standard of workmanship in industrial radiography

Fabrication and characterization of Gd2O2SO4:Tb3+ phosphors by sol-gel method

Science.gov (United States)

Aritman, I.; Yildirim, S.; Kisa, A.; Guleryuz, L. F.; Yurddaskal, M.; Dikici, T.; Celik, E.

2017-02-01

The objective of the innovative approaches of the scintillation materials to be used in the digital portal imaging systems in the radiotherapy applications is to research the GOS material production that has been activated with the rare earth elements (RE), to produce the scintillation detectors that have a rapid imaging process with a lesser radiation and higher image quality from these materials and to apply the radiographic imaging systems. The GOS: Tb3+ showed high emission peak and high x-ray absorption properties which have been determined for application to mammography and dental radiography. In this study, Gd2O2SO4:Tb3+ phosphors were fabricated by the sol-gel method that is a unique technique and not previously applied. Besides, the structural characterization of GOS: Tb3+ has been investigated. The strongest emission peak located at 549 nm under 312 nm UV light excitation was appeared on the GOS: Tb3+ phosphor particles. The characterization processing optimized by using FTIR, DTA-TG, XRD, XPS, SEM and the luminescence spectroscopy.

Specific radiography technique

International Nuclear Information System (INIS)

Abdul Nassir Ibrahim; Azali Muhammad; Ab. Razak Hamzah; Abd. Aziz Mohamed; Mohamad Pauzi Ismail

2008-01-01

Beside radiography testing using x-ray machine and gamma source, there are several technique that developed specifically to complete the testing that cannot be done with the two earlier. This technique was specific based on several factor, for the example, the advantages of neutron and electron using to show the image was unique compare to x-ray and gamma. Besides that, these special radiography techniques maybe differ in how to detect the radiation get through the object. These technique can used to inspect thin or specimen that contained radioactive material. There are several technique will discussed in this chapter such as neutron radiography, electron radiography, fluoroscopy and also autoradiography.

Bone X-Ray (Radiography)

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

Bone X-Ray (Radiography)

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

Bone X-Ray (Radiography)

Science.gov (United States)

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

Radiography - A conceptual approach

Energy Technology Data Exchange (ETDEWEB)

Ahonen, Sanna-Mari [Department of Nursing Science and Health Administration, University of Oulu, P.O. Box 5000, FIN-90014 (Finland)], E-mail: sanna-mari.ahonen@oulu.fi

2008-11-15

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

Radiography - A conceptual approach

International Nuclear Information System (INIS)

Ahonen, Sanna-Mari

2008-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Osti, Michael; Benedetto, Karl Peter [Academic Hospital Feldkirch, Department for Trauma Surgery and Sports Traumatology, Feldkirch (Austria); Krawinkel, Alessa [Academic Hospital Feldkirch, Department for Radiology, Feldkirch (Austria)

2014-12-15

Intra- and postoperative validation of anatomic footprint replication in posterior cruciate ligament (PCL) reconstruction can be conducted using fluoroscopy, radiography, or computed tomography (CT) scans. However, effectiveness and exposure to radiation of these imaging modalities are unknown. The objective of this study was to evaluate the comparative effectiveness of fluoroscopy, radiography, and CT in detecting femoral and tibial tunnel positions following an all-inside reconstruction of the PCL ligament in vivo. The study design was a retrospective case series. Intraoperative fluoroscopic images, postoperative radiographs, and CT scans were obtained in 50 consecutive patients following single-bundle PCL reconstruction. The centers of the tibial and femoral tunnel apertures were identified and correlated to measurement grid systems. The results of fluoroscopic, radiographic, and CT measurements were compared to each other and accumulated radiation dosages were calculated. Comparing the imaging groups, no statistically significant difference could be detected for the reference of the femoral tunnel to the intercondylar depth and height, for the reference of the tibial tunnel to the mediolateral diameter of the tibial plateau and for the superoinferior distance of the tibial tunnel entry to the tibial plateau and to the former physis line. Effective doses resulting from fluoroscopic, radiographic, and CT exposure averaged 2.9 mSv, standard deviation (±SD) 4.1 mSv, to 1.3 ± 0.8 mSv and to 3.6 ± 1.0 mSv, respectively. Fluoroscopy, radiography, and CT yield approximately equal effectiveness in detecting parameters used for quality validation intra- and postoperatively. An accumulating exposure to radiation must be considered. (orig.)

Assessment of clinical image quality in feline chest radiography with a needle-image plate (NIP) storage phosphor system. An approach to the evaluation of image quality in neonatal radiography; Untersuchungen zur Qualitaet von Thoraxaufnahmen bei Katzen mit einem auf einer Nadelstruktur basierenden Speicherfoliensystem. Modelluntersuchungen zur Bewertung der Bildqualitaet bei Neugeborenen

Energy Technology Data Exchange (ETDEWEB)

Ludewig, E.; Bosch, B.; Gaebler, K.; Succow, D.; Werrmann, A. [Klinik fuer Kleintiere, Univ. Leipzig (Germany); Hirsch, W.; Sorge, I. [Abt. Paediatrische Radiologie, Univ. Leipzig (Germany); Gosch, D. [Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Univ. Leipzig (Germany)

2010-02-15

Purpose: Is the image quality of thoracic radiographs of cats obtained with a needle-based storage phosphor (NIP) system superior to conventional (PIP) storage phosphor radiography? Is it possible to decrease the mAs by 50% with the NIP system without significant loss of information? Materials and Methods: From each of the 20 animals, three lateral radiographs were acquired. The assessment of the exposure level was based on the generated IgM-values. Images were acquired 1. with the NIP system and exposure settings equivalent to an IgM of 1.9, 2. with the PIP system and identical settings, and 3. with the NIP system and 50% of the mAs. Six blinded readers used a 5-step scale to assess the reproducibility of five anatomical structures and image noise sensation. Data were analysed using Visual Grading Characteristics Analysis (VGC). Results: While applying identical exposure values the NIP system for all features revealed superior ratings to those of the PIP system (AUC{sub VGC} values ranged from 0.81 for ''cardiac silhouette'' to 0.92 for ''trachea''). Even when reducing mAs by 50% in the NIP images all features were rated better compared with the PIP images and original settings (AUC{sub VGC} values ranged from 0.60 for ''cardiac silhouette'' to 0.74 for ''trachea'' and ''caudal thoracic field''). Conclusion: The NIP system demonstrates clearly better image quality compared to the reference PIP system. A dose reduction of 50% seems to be possible without relevant detraction from image quality. The results obtained in the animal model are valid for simulating conditions in neonatal radiological practise. (orig.)

Bone X-Ray (Radiography)

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

Bone X-Ray (Radiography)

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

Detection of bone erosions in rheumatoid arthritis wrist joints with magnetic resonance imaging, computed tomography and radiography

DEFF Research Database (Denmark)

Døhn, Uffe Møller; Ejbjerg, Bo J; Hasselquist, Maria

2008-01-01

, specificity and accuracy (concordance) of MRI for detecting erosions were 61%, 93% and 77%, respectively, while the respective values were 24%, 99% and 63% for radiography. The intramodality agreements when measuring erosion volumes were high for both CT and MRI (Spearman correlation coefficients 0.92 and 0...... sensitivity and good specificity and accuracy for detection of erosions in rheumatoid arthritis and healthy wrist bones, while radiography showed very low sensitivity. The tested volumetric method was highly reproducible and correlated to scores of erosions....... measuring volumes of erosions on CT and MRI is reproducible and correlated to semiquantitative assessments (scores) of erosions on CT, MRI and radiography. METHODS: Seventeen patients with rheumatoid arthritis and four healthy control individuals underwent CT, MRI and radiography of one wrist, performed...

Temporal digital subtraction radiography with a personal computer digital workstation

International Nuclear Information System (INIS)

Kircos, L.; Holt, W.; Khademi, J.

1990-01-01

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

The application and development of radiography technology based on x-ray

Science.gov (United States)

Chen, Hao; Xu, Zhou; Li, Ming

2009-07-01

Modern Radiography technology was combined with radiation physics and modern imaging processing, which was an important branch of information obtainment and processing. We can get the inside information of the object, by the X ray's attenuation when the ray penetrated the object, and depending on the computer's fast processing, we can see the slice imaging of the object. Computerized Tomography, Computerized Laminography, and Digital Radiography were important parts in Radiography. The institute of applied electronics, CAEP in the research of intense radiation had developed several advanced radiation sources and some advanced radiography imaging systems, for example, S-band small spot linear accelerator, full solid state modulator, C-band linear accelerator, high energy Tera-hertz radiation source and CT technology based on cone beam, DR technology, CL Technology etc. Such imaging systems had been applied in industrial NDT/NDE, security check, medical diagnosis, petroleum and gas pipeline inspection system etc.

Gamma radiography and its technological application

International Nuclear Information System (INIS)

Courtois, G.

1962-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Son, Soon-Yong [Asan Medical Center, Seoul (Korea, Republic of); Choe, Bo-Young [The Catholic University of Korea, Seoul (Korea, Republic of); Lee, Jeong-Woo [Konkuk University Hospital, Seoul (Korea, Republic of); Kim, Jung-Min [Korea University, Seoul (Korea, Republic of); Jeong, Hoi-Woun [The Baekseok Culture University College of Korea, Cheon-an (Korea, Republic of); Kim, Ham-Gyum; Kim, Wha-Sun [The Ansan University College of Korea, Ansan (Korea, Republic of); Lyu, Kwang-Yeul; Min, Jung-Whan [The Shingu University College of Korea, Seongnam (Korea, Republic of); Kim, Ki-Won [Samsung Medical Center, Seoul (Korea, Republic of)

2014-12-15

Regular quality assurance (QA) of image quality is essential for reasonable patient dose and accurate treatment. Thus, QA should be performed as a routine for correction. The purpose of this study was to evaluate the modulation transfer function (MTF), the noise power spectrum (NPS) and the detective quantum efficiency (DQE) of the computed radiography (CR) system and the digital radiography (DR) system by using the edge method in megavoltage X-ray imaging (MVI). We used an edge block, which consisting of tungsten with dimensions of 19 (thickness) x 10 (length) x 1 (width) cm{sup 3} and measured the pre-sampling MTF by using a 6-megavolt (MV) energy. Computed radiography with an image plate (CR-IP) showed the values of 0.4 mm{sup -1} and 1.19 mm{sup -1} for MTF 0.5 and 0.1. In the DR group, Elekta iViewGT showed the highest value of 0.27 mm{sup -1} for MTF 0.5, and Siemens BEAMVIEW{sup PLUS} showed the highest value of 0.98 mm{sup -1} for MTF 0.1. In CR, the NPS of CR-IP showed a favorable noise distribution. Thus, in the DR group, the NPS of Elekta iViewGT showed the highest noise distribution. CR-IP showed values at peak DQE and 1 mm{sup -1} DQE of 0.0013 and 0.00011, respectively. In the DR group, Elekta iViewGT showed the best efficiency at a peak DQE of 0.0009, and Siemens BEAMVIEW{sup PLUS} showed the best efficiency at a 1-mm{sup -1} DQE of 0.000008. The edge method produced fast assessments of the MTF and the DQE. We could validate the evaluation of the edge method by comparing of the CR system to the DR system. This study demonstrated that the edge method can be used for not only traditional QA imaging but also quantitative MTF, NPS and DQE measurements in detector development.

International Neutron Radiography Newsletter

DEFF Research Database (Denmark)

Domanus, Joseph Czeslaw

1986-01-01

At the First World Conference on Neutron Radiography i t was decided to continue the "Neutron Radiography Newsletter", published previously by J.P. Barton, as the "International Neutron Radiography Newsletter" (INRNL), with J.C. Doraanus as editor. The British Journal of Non-Destructive Testing...

Unactivated yttrium tantalate phosphor

International Nuclear Information System (INIS)

Reddy, V.B.; Cheung, H.K.

1992-01-01

This patent describes an unactivated yttrium tantalate phosphor having M prime monoclinic structure and containing one or more additives of Rb and Al in an amount of between about 0.001 to 0.1 moles per mole of yttrium tantalate to improve brightness under X-radiation. This patent also describes an unactivated yttrium tantalate phosphor having M prime monoclinic structure and containing additives of Sr in an amount of between 0.001 to 0.1 moles per mole of yttrium tantalate and one or more of Rb and Al in an amount of between 0.001 to 0.1 moles per mole of yttrium tantalate the phosphor exhibiting a greater brightness under X-radiation than the phosphor absent Rb and Al

Dose-image quality study in digital chest radiography using Monte Carlo simulation

International Nuclear Information System (INIS)

Correa, S.C.A.; Souza, E.M.; Silva, A.X.; Lopes, R.T.; Yoriyaz, H.

2008-01-01

One of the main preoccupations of diagnostic radiology is to guarantee a good image-sparing dose to the patient. In the present study, Monte Carlo simulations, with MCNPX code, coupled with an adult voxel female model (FAX) were performed to investigate how image quality and dose in digital chest radiography vary with tube voltage (80-150 kV) using air-gap technique and a computed radiography system. Calculated quantities were normalized to a fixed value of entrance skin exposure (ESE) of 0.0136 R. The results of the present analysis show that the image quality for chest radiography with imaging plate is improved and the dose reduced at lower tube voltage

Qualitative discussion of quantitative radiography

International Nuclear Information System (INIS)

Berger, H.; Motz, J.W.

1975-01-01

Since radiography yields an image that can be easily related to the tested object, it is superior to many nondestructive testing techniques in revealing the size, shape, and location of certain types of discontinuities. The discussion is limited to a description of the radiographic process, examination of some of the quantitative aspects of radiography, and an outline of some of the new ideas emerging in radiography. The advantages of monoenergetic x-ray radiography and neutron radiography are noted

Radiation Safety in Industrial Radiography. Specific Safety Guide (French Edition); Surete radiologique en radiographie industrielle

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-05-15

This Safety Guide provides recommendations for ensuring radiation safety in industrial radiography used in non-destructive testing. This includes industrial radiography work that utilizes X ray and gamma sources, both in Horizontal-Ellipsis shielded facilities that have effective engineering controls and in outside shielded facilities using mobile sources. Contents: 1. Introduction; 2. Duties and responsibilities; 3. Safety assessment; 4. Radiation protection programme; 5. Training and qualification; 6. Individual monitoring of workers; 7. Workplace monitoring; 8. Control of radioactive sources; 9. Safety of industrial radiography sources and exposure devices; 10. Radiography in shielded enclosures; 11. Site radiography; 12. Transport of radioactive sources; 13. Emergency preparedness and response; Appendix: IAEA categorization of radioactive sources; Annex I: Example safety assessment; Annex II: Overview of industrial radiography sources and equipment; Annex III: Examples of accidents in industrial radiography.

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

Energy Technology Data Exchange (ETDEWEB)

Creanga, Adriana Gabriela [Division of Dental Diagnostic Science, Rutgers School of Dental Medicine, Newark (United States); Geha, Hassem; Sankar, Vidya; Mcmahan, Clyde Alex; Noujeim, Marcel [University of Texas Health Science Center San Antonio, San Antonio (United States); Teixeira, Fabrico B. [Dept. of Endodontics, University of Iowa, Iowa City (United States)

2015-09-15

The purpose of this study was to evaluate and compare the efficacy of cone-beam computed tomography (CBCT) and digital intraoral radiography in diagnosing simulated small external root resorption cavities. Cavities were drilled in 159 roots using a small spherical bur at different root levels and on all surfaces. The teeth were imaged both with intraoral digital radiography using image plates and with CBCT. Two sets of intraoral images were acquired per tooth: orthogonal (PA) which was the conventional periapical radiograph and mesioangulated (SET). Four readers were asked to rate their confidence level in detecting and locating the lesions. Receiver operating characteristic (ROC) analysis was performed to assess the accuracy of each modality in detecting the presence of lesions, the affected surface, and the affected level. Analysis of variation was used to compare the results and kappa analysis was used to evaluate interobserver agreement. A significant difference in the area under the ROC curves was found among the three modalities (P=0.0002), with CBCT (0.81) having a significantly higher value than PA (0.71) or SET (0.71). PA was slightly more accurate than SET, but the difference was not statistically significant. CBCT was also superior in locating the affected surface and level. CBCT has already proven its superiority in detecting multiple dental conditions, and this study shows it to likewise be superior in detecting and locating incipient external root resorption.

Simulation of the radiography formation process from CT patient volume

International Nuclear Information System (INIS)

Bifulco, P.; Cesarelli, M.; Verso, E.; Roccasalva Firenze, M.; Sansone, M.; Bracale, M.

1998-01-01

The aim of this work is to develop an algorithm to simulate the radiographic image formation process using volumetric anatomical data of the patient, obtained from 3D diagnostic CT images. Many applications, including radiographic driven surgery, virtual reality in medicine and radiologist teaching and training, may take advantage of such technique. The designed algorithm has been developed to simulate a generic radiographic equipment, whatever oriented respect to the patient. The simulated radiography is obtained considering a discrete number of X-ray paths departing from the focus, passing through the patient volume and reaching the radiographic plane. To evaluate a generic pixel of the simulated radiography, the cumulative absorption along the corresponding X-ray is computed. To estimate X-ray absorption in a generic point of the patient volume, 3D interpolation of CT data has been adopted. The proposed technique is quite similar to those employed in Ray Tracing. A computer designed test volume has been used to assess the reliability of the radiography simulation algorithm as a measuring tool. From the errors analysis emerges that the accuracy achieved by the radiographic simulation algorithm is largely confined within the sampling step of the CT volume. (authors)

Radiography at CERN

CERN Multimedia

HSE Unit

2014-01-01

What is industrial radiography? It is a non-destructive method with a wide variety of applications, such as inspecting the quality of a weld. It uses high-energy radioactive sources or an X-ray generator.   Is this inspection technique used at CERN? Yes, it is widely used at CERN by the EN-MME Group, which outsources the work to one or more companies, depending on the workload. Is it possible to carry out radiography anywhere at CERN? Yes, it is possible to carry out radiography in any building/accelerator/experiment area at CERN (including in areas which are not normally subject to radiological hazards). When is radiography carried out? It normally takes place outside of working hours (7 p.m. to 6 a.m.). How will I know if radiography is taking place in my building? If this activity is planned in a CERN building, notices will be affixed to all of its main entrance doors at least 24 hours in advance. What are the risks? There is a risk of exposure to very high levels of radiation, dep...

An overview of digital radiography

International Nuclear Information System (INIS)

Aweligiba, S. A.

2013-04-01

The medical application of radiography has gained wider study since diagnostic radiology plays a very important role in modern medicine for fast diagnosis and therapy. Digital radiography is a relatively new technology that promises greater accuracy, lesser dose and better manipulation of patient radiology images in hospitals. In this study, a general discussion on digital radiography has been presented. The presentation focuses on the optimisation of doses to patients in the medical application of digital radiography, quality control and quality assurance. A brief presentation on performance indicators in digital radiography has also been presented. The advantages of digital radiography over the conventional film/screen system have been elaborated and its limitations are also outlined. (author)

Comparison study on CNR and SNR of thoracic spine lateral radiography

Energy Technology Data Exchange (ETDEWEB)

Kim, Ki Won [Dept. of Radiology, Samsung Medical Center, Seoul (Korea, Republic of); Min, Jung Whan; Lyu, Kwang Yeul [Dept. of Radiology, Shingu University, Sungnam (Korea, Republic of); Kim, Jung Min [Dept. of Radiological Science, College of Health Science, Korea University, Seoul (Korea, Republic of); Jeong, Hei Woun [Dept. of Radiological Science, Beakseok Culture University, Cheonan (Korea, Republic of); Lee, Joo Ah [Dept. of Oncology, Catholic University of Korea Incheon St.Mary,s Hospital, Incheon (Korea, Republic of); Jung, Jae Hong [Dept. of Oncology, Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of); Sung, Dong Chan [Dept. of Radiology, Dong Guk University Medical Center, Seoul (Korea, Republic of); Park, Soon Cheol [Dept. of Radiology, Kang Dong Kyung Hee University Medical Center, Seoul (Korea, Republic of)

2013-12-15

This study was proven for the T-spine breathing technique in lateral projection, using computer radiography (CR), charge coupled device (CCD), indirect digital radiography (IDR) and direct digital radiography (DDR). All images were evaluated and compared with CNR and SNR measured with the mean pixels and the standard deviation as setting ROI of spinous process, pedicle, vertebral body, intervertebral foramen and intervertebral disk using Image J. In experiment results of 4 type detectors, T-spine breathing technique was indicated as excellent in ROI of spinous process, pedicle, vertebral body, intervertebral foramen and intervertebral disk. As T-spine breathing technique indicated excellent images compared to the existing T-spine lateral radiography, this method would be useful for elderly patients who have difficulty in deep exhalation. This study was indicated the application possibility of T-spine breathing technique by presenting contrast to noise ratio (CNR) and signal to noise ratio (SNR) with quantitative value in 4 type detectors.

White light quality of phosphor converted light-emitting diodes: A phosphor materials perspective of view

International Nuclear Information System (INIS)

Sommer, Christian; Hartmann, Paul; Pachler, Peter; Hoschopf, Hans; Wenzl, Franz P.

2012-01-01

Highlights: ► We discuss the impact of the optical properties of a phosphor for colour temperature constancy in solid state lighting. ► Quantitative evaluation of permissible variations of the optical properties for batch-to-batch reproducibility. ► Quantitative evaluation of permissible variations of the optical properties upon temperature increase. ► Quantitative evaluation of permissible variations of the optical properties upon materials degradation. - Abstract: For a systematic approach to improve the white light quality of phosphor converted LEDs and to fulfil the demands for colour temperature reproducibility and constancy, it is imperative to understand how variations of the extinction coefficient and the quantum efficiency of the phosphor particles as well as variations of the excitation wavelength of the blue LED die affect the correlated colour temperature of the white LED source. Based on optical ray tracing of a phosphor converted white LED package we deduce permissible values for the variation of a given extinction coefficient and a given quantum efficiency of a phosphor material in order to maintain acceptable colour variations. These quantitative valuations of the required constancy of the optical properties of the phosphors will in particular provide some benchmarks for the synthesis of improved phosphor materials aiming at solid state lighting applications.

Proton nuclear scattering radiography

International Nuclear Information System (INIS)

Duchazeaubeneix, J.C.; Faivre, J.C.; Garreta, D.

1982-10-01

Nuclear scattering of protons allows to radiograph objects with specific properties: direct 3- dimensional radiography, different information as compared to X-ray technique, hydrogen radiography. Furthermore, it is a well adapted method to gating techniques allowing the radiography of fast periodic moving systems. Results obtained on different objects (light and heavy materials) are shown and discussed. The dose delivery is compatible with clinical use, but at the moment, the irradiation time is too long between 1 and 4 hours. Perspectives to make the radiography faster and to get a practical method are discussed

Verification of Radiation Isocenter on Linac Beam 6 MV using Computed Radiography

Science.gov (United States)

Irsal, Muhammad; Hidayanto, Eko; Sutanto, Heri

2017-06-01

Radiation isocenter is more important part of quality assurance for the linear accelerator (Linac) due to radiation isocenter is a main location in irradiation radiotherapy, isocenter can shift when the gantry and collimator rotation. In general, the radiation isocenter verification using a special film. This research was conducted radiation isocenter verification using computed radiography with digital image processing techniques. Image acquisition was done using the modalities of Linac 6 MV with star shot method is star-shaped beam due to rotation of the collimator, gantry and couch. Then do the delineation on each beam to determine the centroid and beam diameter. By the results of verification of radiation isocenter performed on collimator and the couch, it shows that the size diameter for rotational collimator is 0.632 mm and 0.458 mm for the couch. Based on AAPM report 40 about the size of the Linac radiation isocenter diameter used in this study is still in good condition and worth to be operated because the value of the radiation isocenter diameter is below 2 mm.

Verification of Radiation Isocenter on Linac Beam 6 MV using Computed Radiography

International Nuclear Information System (INIS)

Irsal, Muhammad; Hidayanto, Eko; Sutanto, Heri

2017-01-01

Radiation isocenter is more important part of quality assurance for the linear accelerator (Linac) due to radiation isocenter is a main location in irradiation radiotherapy, isocenter can shift when the gantry and collimator rotation. In general, the radiation isocenter verification using a special film. This research was conducted radiation isocenter verification using computed radiography with digital image processing techniques. Image acquisition was done using the modalities of Linac 6 MV with star shot method is star-shaped beam due to rotation of the collimator, gantry and couch. Then do the delineation on each beam to determine the centroid and beam diameter. By the results of verification of radiation isocenter performed on collimator and the couch, it shows that the size diameter for rotational collimator is 0.632 mm and 0.458 mm for the couch. Based on AAPM report 40 about the size of the Linac radiation isocenter diameter used in this study is still in good condition and worth to be operated because the value of the radiation isocenter diameter is below 2 mm. (paper)

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

Directory of Open Access Journals (Sweden)

V.M.V. Machado

2016-02-01

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

Military radiography

International Nuclear Information System (INIS)

Anon.

1993-01-01

Historic military uses of radiography are discussed in this chapter: Battle of Adowa in 1986 was the first. Besides describing the early campaigns in which radiography was used, the author discusses the problems faced: a reliable source of electricity; the problems of extreme heat; moving and breakage of equipment. Numerous historical photographs are included. 9 refs

Comparison of the quality of the chest film between digital radiography and conventional high kV radiography

International Nuclear Information System (INIS)

Zeng Qingsi; Cen Renli; Chen Ling; He Jianxun; Lin Hanfei

2003-01-01

Objective: To evaluate the quality and usefulness of direct digital radiography system in roentgenogram of chest in clinical practice. Methods: 1000 cases of chest roentgenograms with digital radiography and high kV conventional radiography were selected for analysis by 3 senior radiologists. Results: 1. With digital radiography system, the quality of chest film was assessed as grade A in 50.6%, grade B in 38.5%, grade C in 10.9%, and no waste film. 2. With conventional high kV radiography, the quality of chest film was assessed as grade A in 41.1%, grade B in 44.1%, grade C in 13.3%, and waste film in 1.5%. The direct digital radiography was statistically superior to the conventional high kV radiography. 3. The fine structure of the lungs could be revealed in 100.0% of chest roentgenogram with direct digital radiograph system, which was significantly higher than that acquired with the conventional high KV radiography (78.6%, P < 0.001). Conclusion: Direct digital radiography could provide the chest film with better quality than that with the conventional high kV radiography. The direct digital radiography system is easy to operate, fast in capturing imaging and could provide post-processing techniques, which will facilitate the accurate diagnosis of chest radiography

Integrating photo-stimulable phosphor plates into dental and dental hygiene radiography curricula.

Science.gov (United States)

Tax, Cara L; Robb, Christine L; Brillant, Martha G S; Doucette, Heather J

2013-11-01

It is not known whether the integration of photo-stimulable phosphor (PSP) plates into dental and dental hygiene curricula creates unique learning challenges for students. The purpose of this two-year study was to determine if dental hygiene students had more and/or different types of errors when using PSP plates compared to film and whether the PSP imaging plates had any particular characteristics that needed to be addressed in the learning process. Fifty-nine first-year dental hygiene students at one Canadian dental school were randomly assigned to two groups (PSP or film) before exposing their initial full mouth series on a teaching manikin using the parallel technique. The principal investigator determined the number and types of errors based on a specific set of performance criteria. The two groups (PSP vs. film) were compared for total number and type of errors made. Results of the study indicated the difference in the total number of errors made using PSP or film was not statistically significant; however, there was a difference in the types of errors made, with the PSP group having more horizontal errors than the film group. In addition, the study identified a number of unique characteristics of the PSP plates that required special consideration for teaching this technology.

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

International Nuclear Information System (INIS)

Han, S.; Lee, B.; Shin, G.; Choi, J.; Kim, J.; Park, C.; Park, H.; Lee, K.; Kim, Y.

2008-01-01

In this study, diagnostic reference levels (DRLs) were suggested and patient doses were analysed through the dose-area product value in dental radiography. In intraoral radiography, at three sites, i.e. molar, premolar and incisor on the maxilla and acquired third quartile values: 55.5, 46 and 36.5 mGy cm 2 , respectively, were measured. In panoramic, cephalo-metric and cone beam computed tomography, the values were 120.3, 146 and 3203 mGy cm 2 (16 x 18 cm), respectively. It has been shown that, in intraoral radiography, the patient dose changes proportionally to the value of mA s, but the change in extra-oral radiography in response to mA s could not be confirmed. The authors could confirm, however, the difference in dose according to the manufacturer in all dental radiography examinations, except for panoramic radiography. Depending on the size of hospital, there were some differences in patient dose in intraoral radiography, but no difference in patient dose in extra-oral radiography. (authors)

Phosphor investigation in the production of Syrian phosphoric acid using Nuclear Magnetic Resonance

International Nuclear Information System (INIS)

Al-Hassanieh, O.; Al-Hameish, M.

2009-06-01

Nuclear magnetic resonance spectroscopy (NMR) was applied in this work to the industrial process of extraction of uranium from phosphoric acid and to the process of the purification of the phosphoric acid for food proposes. The structural changes of used extraction materials and the organic content of the final product was studied. 13 C , 1 H and 32 P-spectra of all material during the process were recorded. The spectra of the three used extraction materials Bis(2-ethylhexyl Phosphoric Acid)) DEHPA, TriOctyl Phosphine Oxide (TOPO) (C 8 H 1 7) 3 P=O and TriButyl Phosphate (TBP) (C 4 H 9 O) 3 P=O show a partial degradation during the process. The final product ( Phosphoric acid for Food proposes) doesn't contain any organic solvents or extraction material. (author)

Radioluminescent nuclear batteries with different phosphor layers

International Nuclear Information System (INIS)

Hong, Liang; Tang, Xiao-Bin; Xu, Zhi-Heng; Liu, Yun-Peng; Chen, Da

2014-01-01

Highlights: • We present and test the electrical properties of the nuclear battery. • The best thickness range for ZnS:Cu phosphor layer is 12–14 mg cm −2 for 147 Pm radioisotope. • The best thickness range for Y 2 O 2 S:Eu phosphor layer is 17–21 mg cm −2147 Pm radioisotope. • The battery with ZnS:Cu phosphor layer can provide higher energy conversion efficiency. • The mechanism affecting the nuclear battery output performance is revealed. - Abstract: A radioluminescent nuclear battery based on the beta radioluminescence of phosphors is presented, and which consists of 147 Pm radioisotope, phosphor layers, and GaAs photovoltaic cell. ZnS:Cu and Y 2 O 2 S:Eu phosphor layers for various thickness were fabricated. To investigate the effect of phosphor layer parameters on the battery, the electrical properties were measured. Results indicate that the optimal thickness ranges for the ZnS:Cu and Y 2 O 2 S:Eu phosphor layers are 12 mg cm −2 to 14 mg cm −2 and 17 mg cm −2 to 21 mg cm −2 , respectively. ZnS:Cu phosphor layer exhibits higher fluorescence efficiency compared with the Y 2 O 2 S:Eu phosphor layer. Its spectrum properly matches the spectral response of GaAs photovoltaic cell. As a result, the battery with ZnS:Cu phosphor layer indicates higher energy conversion efficiency than that with Y 2 O 2 S:Eu phosphor layer. Additionally, the mechanism of the phosphor layer parameters that influence the output performance of the battery is discussed through the Monte Carlo method and transmissivity test

Concentration and wavelength dependent frequency downshifting photoluminescence from a Tb3+ doped yttria nano-phosphor: A photochromic phosphor

Science.gov (United States)

Yadav, Ram Sagar; Rai, Shyam Bahadur

2018-03-01

In this article, the Tb3+ doped Y2O3 nano-phosphor has been synthesized through solution combustion method. The structural measurements of the nano-phosphor have been carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques, which reveal nano-crystalline nature. The Fourier transform infrared (FTIR) measurements reveal the presence of different molecular species in the nano-phosphor. The UV-Vis-NIR absorption spectrum of the nano-phosphor shows large number of bands due to charge transfer band (CTB) and 4f-4f electronic transitions of Tb3+ ion. The Tb3+ doped Y2O3 nano-phosphor emits intense green downshifting photoluminescence centered at 543 nm due to 5D4 → 7F5 transition on excitation with 350 nm. The emission intensity of the nano-phosphor is optimized at 1.0 mol% concentration of Tb3+ ion. When the as-synthesized nano-phosphor is annealed at higher temperature the emission intensity of the nano-phosphor enhances upto 5 times. The enhancement in the emission intensity is due to an increase in crystallinity of the nano-phosphor, reduction in surface defects and optical quenching centers. The CIE diagram reveals that the Tb3+ doped nano-phosphor samples show the photochromic nature (color tunability) with a change in the concentration of Tb3+ ion and excitation wavelength. The lifetime measurement indicates an increase in the lifetime for the annealed sample. Thus, the Tb3+ doped Y2O3 nano-phosphor may be used in photochromic displays and photonic devices.

Proton nuclear scattering radiography

International Nuclear Information System (INIS)

Saudinos, J.

1982-04-01

Nuclear scattering of protons allows to radiograph objects with specific properties: 3-dimensional radiography, different information as compared to X-ray technique, hydrogen radiography. Furthermore the nuclear scattering radiography (NSR) is a well adapted method to gating techniques allowing the radiography of fast periodic moving objects. Results obtained on phantoms, formalin fixed head and moving object are shown and discussed. The dose delivery is compatible with clinical use, but at the moment, the irradiation time is too long between 1 and 4 hours. Perspectives to make the radiograph faster and to get a practical method are discussed

MULTI-PHOTON PHOSPHOR FEASIBILITY RESEARCH

Energy Technology Data Exchange (ETDEWEB)

R. Graham; W. Chow

2003-05-01

Development of multi-photon phosphor materials for discharge lamps represents a goal that would achieve up to a doubling of discharge (fluorescent) lamp efficacy. This report reviews the existing literature on multi-photon phosphors, identifies obstacles in developing such phosphors, and recommends directions for future research to address these obstacles. To critically examine issues involved in developing a multi-photon phosphor, the project brought together a team of experts from universities, national laboratories, and an industrial lamp manufacturer. Results and findings are organized into three categories: (1) Multi-Photon Systems and Processes, (2) Chemistry and Materials Issues, and (3) Concepts and Models. Multi-Photon Systems and Processes: This category focuses on how to use our current understanding of multi-photon phosphor systems to design new phosphor systems for application in fluorescent lamps. The quickest way to develop multi-photon lamp phosphors lies in finding sensitizer ions for Gd{sup 3+} and identifying activator ions to red shift the blue emission from Pr{sup 3+} due to the {sup 1}S{sub 0} {yields} {sup 1}I{sub 6} transition associated with the first cascading step. Success in either of these developments would lead to more efficient fluorescent lamps. Chemistry and Materials Issues: The most promising multi-photon phosphors are found in fluoride hosts. However, stability of fluorides in environments typically found in fluorescent lamps needs to be greatly improved. Experimental investigation of fluorides in actual lamp environments needs to be undertaken while working on oxide and oxyfluoride alternative systems for backup. Concepts and Models: Successful design of a multi-photon phosphor system based on cascading transitions of Gd{sup 3+} and Pr{sup 3+} depends critically on how the former can be sensitized and the latter can sensitize an activator ion. Methods to predict energy level diagrams and Judd-Ofelt parameters of multi

Phosphor blends for high-CRI fluorescent lamps

Science.gov (United States)

Setlur, Anant Achyut [Niskayuna, NY; Srivastava, Alok Mani [Niskayuna, NY; Comanzo, Holly Ann [Niskayuna, NY; Manivannan, Venkatesan [Clifton Park, NY; Beers, William Winder [Chesterland, OH; Toth, Katalin [Pomaz, HU; Balazs, Laszlo D [Budapest, HU

2008-06-24

A phosphor blend comprises at least two phosphors each selected from one of the groups of phosphors that absorb UV electromagnetic radiation and emit in a region of visible light. The phosphor blend can be applied to a discharge gas radiation source to produce light sources having high color rendering index. A phosphor blend is advantageously includes the phosphor (Tb,Y,LuLa,Gd).sub.x(Al,Ga).sub.yO.sub.12:Ce.sup.3+, wherein x is in the range from about 2.8 to and including 3 and y is in the range from about 4 to and including 5.

The stationary neutron radiography system

International Nuclear Information System (INIS)

Weeks, A.A.; Newell, D.L.; Heidel, C.C.

1990-01-01

To provide the high intensity neutron beam and support systems necessary for radiography, the Stationary Neutron Radiography System was constructed at McClellan Air Force Base. The Stationary Neutron Radiography System utilizes a one megawatt TRIGA reactor contained in an Aluminium tank surrounded by eight foot thick concrete walls. There are four neutron beam tubes at inclined angles from the reactor core to separate radiography bays. In three of the bays, robotic systems manipulate aircraft components in the neutron beam, while real-time imaging systems provide images concurrent with the irradiation. Film radiography of smaller components is performed in the remaining bay

Glandular dose and image quality control in mammography facilities with computerized radiography systems; Dose glandular e controle de qualidade da imagem em servicos de mamografia com sistema de radiografia computadorizada

Energy Technology Data Exchange (ETDEWEB)

Dantas, Marcelino Vicente de Almeida

2010-07-01

Breast cancer is the most common cancer among women, and early detection is critical to its diagnosis and treatment. To date, the most effective method for early detection of breast cancer has been x-ray mammography for which the screen/film (SF) technique has been the gold standard. However, even though SF combinations have been improved and optimized over the years for breast imaging, there are some critical limitations, including a narrow exposure range, image artifacts, film processing problems, and inflexibility in image processing and film management. In recent years, digital mammography has been introduced in cancer screening programmes with the screen/film techniques gradually being phased out. Computed radiography (CR), also commonly known as photostimulable phosphor (PSP) imaging or storage phosphor, employs reusable imaging plates and associated hardware and software to acquire and to display digital projection radiographs. In this work, a protocol model was tested for performing image quality control and average glandular dose (AGD) evaluation in 19 institutions with computed radiography systems for mammography. The protocol was validated through tests at the Laboratorio de Radioprotecao Aplicada a Mamografia (LARAM) from the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN). The image quality visual evaluation of CDMAM phantom showed that 53% of the facilities were able to produce images of excellent quality. Furthermore, the automated evaluation of image quality, using the analyze software cdcom.exe, showed that 57% of the images were considered to be of good quality. The detector linearity test showed that the CR response is very linear, where 95% of facilities evaluated were considered to be compliant. For the image noise was found that only 20% of facilities are in agreement with the parameters established for this test. The average glandular doses, which patients may be getting to perform an examination, were below the action levels

Recovering uranium from phosphoric acid

International Nuclear Information System (INIS)

Anon.

1979-01-01

Wet-process phosphoric acid contains a significant amount of uranium. This uranium totals more than 1,500 tons/yr in current U.S. acid output--and projections put the uranium level at 8,000 tons/yr in the year 2000. Since the phosphoric acid is a major raw material for fertilizers, uranium finds its way into those products and is effectively lost as a resource, while adding to the amount of radioactive material that can contaminate the food chain. So, resource-conservation and environmental considerations both make recovery of the uranium from phosphoric acid desirable. This paper describes the newly developed process for recovering uranium from phosphoric acid by using solvent-extraction technique. After many extractants had been tested, the researchers eventually selected the combination of di (2-ethylhexyl) phosphoric acid (DEPA) and trioctylphosphine oxide (TOPO) as the most suitable. The flowscheme of the process is included

Chest X-Ray (Chest Radiography)

Science.gov (United States)

... Resources Professions Site Index A-Z X-ray (Radiography) - Chest Chest x-ray uses a very small dose ... Radiography? What is a Chest X-ray (Chest Radiography)? The chest x-ray is the most commonly performed diagnostic ...

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

Science.gov (United States)

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

46 CFR 151.50-23 - Phosphoric acid.

Science.gov (United States)

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Phosphoric acid. 151.50-23 Section 151.50-23 Shipping... BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-23 Phosphoric acid. (a) The term phosphoric acid as used in this subpart shall include, in addition to phosphoric acid, aqueous solutions of...

JRR-3 neutron radiography facility

International Nuclear Information System (INIS)

Matsubayashi, M.; Tsuruno, A.

1992-01-01

JRR-3 neutron radiography facility consists of thermal neutron radiography facility (TNRF) and cold neutron radiography facility (CNRF). TNRF is installed in JRR-3 reactor building. CNRF is installed in the experimental beam hall adjacent to the reactor building. (author)

Patient risk from interproximal radiography

International Nuclear Information System (INIS)

Gibbs, S.J.; Pujol, A. Jr.; Chen, T.S.; Malcolm, A.W.; James, A.E. Jr.

1984-01-01

Computer simulation methods for determining patient dose from dental radiography have demonstrated that patient risk from a two-film interproximal examination ranges from 1.1 X 10(-8) to 3.4 X 10(-7) using 90-kVp beams, depending on film speed, projection technique, and age and sex of the patient. Further, changing from a short-cone round-beam to a long-cone technique with rectangular collimation reduces risk by a factor of 2.9, independent of other factors

Applicaton of fluorometallic screens for paper radiography

International Nuclear Information System (INIS)

Domanus, J.D.

1983-07-01

After the description of the fluorometallic screens and their spectral sensitivity their sensitometric properties are reviewed. Characteristic curves and exposure charts were computed for the structurix IC paper, exposed with ordinary fluorescent IC 2 as well as luorometallic RCF screens. From them relative speed, contrast and exposure latitude were computed. Radiographic image quality was investigated using ISO wire IQI's and ASTM penetrometers and the constant exposure methods. The investigation has shown that it is possible and advantageous to use fluorometallic screens for paper radiography, especially above the low kilovoltage range. (author)

Tuning the diurnal natural daylight with phosphor converted white LED – Advent of new phosphor blend composition

International Nuclear Information System (INIS)

Kim, Yoon Hwa; Arunkumar, Paulraj; Park, Seung Hyok; Yoon, Ho Shin; Im, Won Bin

2015-01-01

Highlights: • Designed phosphor blend that mimics diurnal daylight for health benefits. • Developed new phosphor blend composition that mimics natural sunlight under near UV. • The phosphor blend also exhibits high CRI (≥90) under blue LED excitation. • Fabricated WLED exhibited ∼91% spectral resemblance with daylight at 4500 K. • While ∼39.2% spectral resemblance were observed for YAG:Ce 3+ at 4500 K. - Abstract: We demonstrate the feasibility of developing phosphor converted white LED (pc-WLED) that mimics diurnal natural daylight with the newly designed phosphor blend in the color temperature (CCT) 2700–6000 K for health benefits. Natural daylight (sunlight) spectrum possesses broad emission in the visible region and closely approximates black body radiator, with color rendition index (CRI) of 100 under wide CCT (2500–6500 K). Current white light LEDs although are efficient and durable, they are not broad enough compared to daylight. We report new phosphor blend based on Sr 3 MgSi 2 O 8 :Eu 2+ blue phosphor with broad emission and high CRI ≥ 96 under both near UV and blue excitation. The fabricated WLED has exhibited ∼91% spectral resemblance with natural daylight compared to 39.2% for YAG:Ce 3+ white LED at 4500 K. The developed phosphor blend tunes the spectrum in wider CCT and would be a prospective candidate for full spectrum daylight WLED

Simulation of the radiography formation process from CT patient volume

Energy Technology Data Exchange (ETDEWEB)

Bifulco, P; Cesarelli, M; Verso, E; Roccasalva Firenze, M; Sansone, M; Bracale, M [University of Naples, Federico II, Electronic Engineering Department, Bioengineering Unit, Via Claudio, 21 - 80125 Naples (Italy)

1999-12-31

The aim of this work is to develop an algorithm to simulate the radiographic image formation process using volumetric anatomical data of the patient, obtained from 3D diagnostic CT images. Many applications, including radiographic driven surgery, virtual reality in medicine and radiologist teaching and training, may take advantage of such technique. The designed algorithm has been developed to simulate a generic radiographic equipment, whatever oriented respect to the patient. The simulated radiography is obtained considering a discrete number of X-ray paths departing from the focus, passing through the patient volume and reaching the radiographic plane. To evaluate a generic pixel of the simulated radiography, the cumulative absorption along the corresponding X-ray is computed. To estimate X-ray absorption in a generic point of the patient volume, 3D interpolation of CT data has been adopted. The proposed technique is quite similar to those employed in Ray Tracing. A computer designed test volume has been used to assess the reliability of the radiography simulation algorithm as a measuring tool. From the errors analysis emerges that the accuracy achieved by the radiographic simulation algorithm is largely confined within the sampling step of the CT volume. (authors) 16 refs., 12 figs., 1 tabs.

Receiver operating characteristic curve evaluation on computed radiography: an experimental study

International Nuclear Information System (INIS)

Yu Zixi; Wang Changyuan; Xu Yue; Xie Jindong; Zhang Menglong; Wang Jian

2003-01-01

Objective: To get the maximum information from computed radiography (CR) output images by changing post-processing parameters. Methods: Six experimental photos of polypropylene balls of 2.0 mm in diameter were taken by means of one time X-ray exposing on an imaging plate (IP) with different post-processing parameters including rotation amount (GA), gray gradation type (GT), rotation center (GC), shifting amount (GS), frequency rank (RN), frequency type (RT), and degree of enhancement (RE). 6 photos were viewed by three students and one radiologist on a 6000 lx illuminance viewbox. Receiver operating characteristic (ROC) curves were made by means of 5-value-differentiation method. Results: The largest mean area value (Az) below ROC curves of a low contrast experimental photo with post-processing parameters GA=1.0, GT=A, GC=1.6, GS=0.3, RN=4.0, RT=R and RE=3.0 was 0.96, and the maximum information was obtained. The smallest mean area value (Az) was 0.78 with changed post-processing parameters GA=0.8, GS=-0.2 and RE=0.5 while other parameters were not changed. The minimum information was obtained from this photo. Conclusion: In order to get the maximum information from a CR output image, the post-processing parameters should be suitably selected

Application of strong phosphoric acid to radiochemistry

International Nuclear Information System (INIS)

Terada, Kikuo

1977-01-01

Not only inorganic and organic compounds but also natural substrances, such as accumulations in soil, are completely decomposed and distilled by heating with strong phosphoric acid for 30 to 50 minutes. As applications of strong phosphoric acid to radiochemistry, determination of uranium and boron by use of solubilization effect of this substance, titration of uranyl ion by use of sulfuric iron (II) contained in this substance, application to tracer experiment, and determination of radioactive ruthenium in environmental samples are reviewed. Strong phosphoric acid is also applied to activation analysis, for example, determination of N in pyrographite with iodate potassium-strong phosphoric acid method, separation of Os and Ru with sulfuric cerium (IV) - strong phosphoric acid method or potassium dechromate-strong phosphoric acid method, analysis of Se, As and Sb rocks and accumulations with ammonium bromide, sodium chloride and sodium bromide-strong phosphoric acid method. (Kanao, N.)

Neutron radiography at the HFR Petten

International Nuclear Information System (INIS)

Markgraf, J.F.W.

1990-03-01

This report contains the five papers on neutron radiography activities at the Petten High Flux Reactor (HFR) presented at the Third World Conference on Neutron Radiography which was held in May 1989 in Osaka, Japan. In addition, a survey on neutron radiography in Europe for industry and research as presented at the SITEF NDT symposium 1989 on European Advances in Non-Destructive Testing, held in Toulouse/France in October 1989 is included. The papers compiled here are concerned with: the neutron radiography services available in Petten; the experience with and applications of neutron radiography at Petten; image evaluation and analysis techniques at Petten; the practical utilization of nitrocellulose film in neutron radiography in Europe; an introduction into the basic principles of neutron radiography; an overview of the neutron radiography facilities in Europe for industry and research; and a survey of typical applications of neutron radiography in industry, research and sciences. It is the intention of this compilation to provide a comprehensive overview of the present Petten activities and European facilities in this young and promising field of non-destructive testing of materials and components from the nuclear and the non-nuclear industries and research organizations, and from the sciences

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

International Nuclear Information System (INIS)

Lima, Camila M. Araujo; Silva, Francisco C.A. da; Araujo, Rilton A.

2013-01-01

According to the International Atomic Energy Agency (IAEA), many efforts have been made by Member states, aiming a better control of radioactive sources. Accidents mostly happened in practices named as high radiological risk and classified by IAEA in categories 1 and 2, being highlighted those related to radiotherapy, large irradiators and industrial radiography. Worldwide, more than 40 radiological accidents have been recorded in the industrial radiography. Worldwide, more than 40 radiological accidents have been recorded in the industrial radiography area, involving 37 workers, 110 members of the public and 12 fatalities. Records display 5 severe radiological accidents in industrial radiography activities in Brazil, in which 7 workers and 19 members of the public were involved. Such events led to hands and fingers radiodermatitis, but to no death occurrence. The purpose of this study is to present a computational program that allows the data acquisition and recording in the company, in such a way to ease a further detailed analysis of radiological event, besides providing the learning cornerstones aiming the avoidance of future occurrences. After one year of the 'Industrial SisRadiologia' computational program application - and mostly based upon the workshop about Analysis and Dose Calculation of Radiological Accidents in Industrial Radiography (Workshop sobre Analise e Calculo de dose de acidentes Radiologicos em Radiografia Industrial - IRD 2012), in which several Radiation Protection officers took part - it can be concluded that the computational program is a powerful tool to data acquisition, as well as, to accidents and incidents events recording and surveying in Industrial Radiography. The program proved to be efficient in the report elaboration to the Brazilian Regulatory Authority, and very useful in workers training to fix the lessons learned from radiological events.

Student Incivility in Radiography Education.

Science.gov (United States)

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.

21 CFR 182.1073 - Phosphoric acid.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Phosphoric acid. 182.1073 Section 182.1073 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN....1073 Phosphoric acid. (a) Product. Phosphoric acid. (b) Conditions of use. This substance is generally...

21 CFR 582.1073 - Phosphoric acid.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Phosphoric acid. 582.1073 Section 582.1073 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1073 Phosphoric acid. (a) Product. Phosphoric acid. (b) Conditions of use. This substance is...

Neutron radiography

International Nuclear Information System (INIS)

Alaa eldin, M.T.

2011-01-01

The digital processing of the neutron radiography images gives the possibility for data quantification. In this case an exact relation between the measured neutron attenuation and the real macroscopic attenuation coefficient for every point of the sample is required. The assumption that the attenuation of the neutron beam through the sample is exponential is valid only in an ideal case where a monochromatic beam, non scattering sample and non background contribution are assumed. In the real case these conditions are not fulfilled and in dependence on the sample material we have more or less deviation from the exponential attenuation law. Because of the high scattering cross-sections of hydrogen (σs=80.26 barn) for thermal neutrons, the problem with the scattered neutrons at quantitative radiography investigations of hydrogenous materials (as PE, Oil, H 2 O, etc) is not trivial. For these strong scattering materials the neutron beam attenuation is no longer exponential and a dependence of the macroscopic attenuation coefficient on the material thickness and on the distance between the sample and the detector appears. When quantitative radiography (2 D) or tomography investigations (3 D) are performed, some image correction procedures for a description of the scattering effect are required. This thesis presents a method that can be used to enhance the neutron radiography image for objects with high scattering materials like hydrogen, carbon and other light materials. This method uses the Monte Carlo code, MCNP5, to simulate the neutron radiography process and get the flux distribution for each pixel of the image and determine the scattered neutrons distribution that causes the image blur and then subtract it from the initial image to improve its quality.

Radiological safety aspects of industrial radiography

International Nuclear Information System (INIS)

Hanekom, A.P.

1983-01-01

Industrial radiography and especially gamma-radiography, has established itself as a very powerful tool in non-destructive testing. Unfortunately there is an amount of risk attached to the use of industrial radiography. The primary causes of radiography accidents include: working conditions, equipment failure and lack of supervisory control. To alleviate the radiological risks involved with gamma-radiography, the Atomic Energy Corporation (AEC) has imposed various conditions for the possession, use, and conveyance of radioactive material. This includes personnel training and equipment specifications

Digital chest radiography

DEFF Research Database (Denmark)

Debess, Jeanne Elisabeth; Johnsen, Karen Kirstine; Thomsen, Henrik

on collimation and dose reduction in digital chest radiography Methods and Materials A retrospective study of digital chest radiography is performed to evaluate the primary x-ray tube collimation of the PA and lateral radiographs. Data from one hundred fifty self-reliant female patients between 15 and 55 years...

Tuning the diurnal natural daylight with phosphor converted white LED – Advent of new phosphor blend composition

Energy Technology Data Exchange (ETDEWEB)

Kim, Yoon Hwa [School of Materials Science and Engineering, Chonnam National University, 300, Yongbong-dong, Buk-gu, Gwangju 500-757 (Korea, Republic of); Research Institute, Force4 Corp., Daechon-dong, Buk-gu, Gwangju 500-470 (Korea, Republic of); Arunkumar, Paulraj [School of Materials Science and Engineering, Chonnam National University, 300, Yongbong-dong, Buk-gu, Gwangju 500-757 (Korea, Republic of); Park, Seung Hyok; Yoon, Ho Shin [Research Institute, Force4 Corp., Daechon-dong, Buk-gu, Gwangju 500-470 (Korea, Republic of); Im, Won Bin, E-mail: imwonbin@jnu.ac.kr [School of Materials Science and Engineering, Chonnam National University, 300, Yongbong-dong, Buk-gu, Gwangju 500-757 (Korea, Republic of)

2015-03-15

Highlights: • Designed phosphor blend that mimics diurnal daylight for health benefits. • Developed new phosphor blend composition that mimics natural sunlight under near UV. • The phosphor blend also exhibits high CRI (≥90) under blue LED excitation. • Fabricated WLED exhibited ∼91% spectral resemblance with daylight at 4500 K. • While ∼39.2% spectral resemblance were observed for YAG:Ce{sup 3+} at 4500 K. - Abstract: We demonstrate the feasibility of developing phosphor converted white LED (pc-WLED) that mimics diurnal natural daylight with the newly designed phosphor blend in the color temperature (CCT) 2700–6000 K for health benefits. Natural daylight (sunlight) spectrum possesses broad emission in the visible region and closely approximates black body radiator, with color rendition index (CRI) of 100 under wide CCT (2500–6500 K). Current white light LEDs although are efficient and durable, they are not broad enough compared to daylight. We report new phosphor blend based on Sr{sub 3}MgSi{sub 2}O{sub 8}:Eu{sup 2+} blue phosphor with broad emission and high CRI ≥ 96 under both near UV and blue excitation. The fabricated WLED has exhibited ∼91% spectral resemblance with natural daylight compared to 39.2% for YAG:Ce{sup 3+} white LED at 4500 K. The developed phosphor blend tunes the spectrum in wider CCT and would be a prospective candidate for full spectrum daylight WLED.

Color stable manganese-doped phosphors

Science.gov (United States)

Lyons, Robert Joseph [Burnt Hills, NY; Setlur, Anant Achyut [Niskayuna, NY; Deshpande, Anirudha Rajendra [Twinsburg, OH; Grigorov, Ljudmil Slavchev [Sofia, BG

2012-08-28

A process for preparing color stable Mn.sup.+4 doped phosphors includes providing a phosphor of formula I; A.sub.x[MF.sub.y]:Mn.sup.+4 I and contacting the phosphor in particulate form with a saturated solution of a composition of formula II in aqueous hydrofluoric acid; A.sub.x[MF.sub.y]; II wherein A is Li, Na, K, Rb, Cs, NR.sub.4 or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; R is H, lower alkyl, or a combination thereof; x is the absolute value of the charge of the [MF.sub.y] ion; and y is 5, 6 or 7. In particular embodiments, M is Si, Ge, Sn, Ti, Zr, or a combination thereof. A lighting apparatus capable of emitting white light includes a semiconductor light source; and a phosphor composition radiationally coupled to the light source, and which includes a color stable Mn.sup.+4 doped phosphor.

Neutron radiography

International Nuclear Information System (INIS)

Bayon, G.

1989-01-01

Neutronography or neutron radiography, a non-destructive test method which is similar in its principle to conventional X-ray photography, presently occupies a marginal position among non-destructive test methods (NDT) (no source of suitable performance or cost). Neutron radiography associated with the ORPHEE reactor permits industrial testing; it can very quickly meet a cost requirement comparable to that of conventional test methods. In 1988, 2500 parts were tested on this unit [fr

Industrial radiography

International Nuclear Information System (INIS)

1994-01-01

This Health and Safety Executive Information Sheet on industrial radiography aims to inform directors and managers of industrial radiography companies on the safety precautions necessary to ensure that their personnel do not exceed dose guidelines for exposure to ionizing radiation. The Ionising Radiations Regulations 1985 (IRR85) require that exposure doses for radiographers are kept as low reasonably practicable. Equipment maintenance, and the employment of proper emergency procedures will help to ensure personnel safety. (UK)

A linear programming computational framework integrates phosphor-proteomics and prior knowledge to predict drug efficacy.

Science.gov (United States)

Ji, Zhiwei; Wang, Bing; Yan, Ke; Dong, Ligang; Meng, Guanmin; Shi, Lei

2017-12-21

In recent years, the integration of 'omics' technologies, high performance computation, and mathematical modeling of biological processes marks that the systems biology has started to fundamentally impact the way of approaching drug discovery. The LINCS public data warehouse provides detailed information about cell responses with various genetic and environmental stressors. It can be greatly helpful in developing new drugs and therapeutics, as well as improving the situations of lacking effective drugs, drug resistance and relapse in cancer therapies, etc. In this study, we developed a Ternary status based Integer Linear Programming (TILP) method to infer cell-specific signaling pathway network and predict compounds' treatment efficacy. The novelty of our study is that phosphor-proteomic data and prior knowledge are combined for modeling and optimizing the signaling network. To test the power of our approach, a generic pathway network was constructed for a human breast cancer cell line MCF7; and the TILP model was used to infer MCF7-specific pathways with a set of phosphor-proteomic data collected from ten representative small molecule chemical compounds (most of them were studied in breast cancer treatment). Cross-validation indicated that the MCF7-specific pathway network inferred by TILP were reliable predicting a compound's efficacy. Finally, we applied TILP to re-optimize the inferred cell-specific pathways and predict the outcomes of five small compounds (carmustine, doxorubicin, GW-8510, daunorubicin, and verapamil), which were rarely used in clinic for breast cancer. In the simulation, the proposed approach facilitates us to identify a compound's treatment efficacy qualitatively and quantitatively, and the cross validation analysis indicated good accuracy in predicting effects of five compounds. In summary, the TILP model is useful for discovering new drugs for clinic use, and also elucidating the potential mechanisms of a compound to targets.

neutron radiography

International Nuclear Information System (INIS)

Barton, J.P.

1993-01-01

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

Improvements in x-ray image converters and phosphors

International Nuclear Information System (INIS)

Rabatin, J.G.

1981-01-01

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

Fluorescent lighting with aluminum nitride phosphors

Science.gov (United States)

Cherepy, Nerine J.; Payne, Stephen A.; Seeley, Zachary M.; Srivastava, Alok M.

2016-05-10

A fluorescent lamp includes a glass envelope; at least two electrodes connected to the glass envelope; mercury vapor and an inert gas within the glass envelope; and a phosphor within the glass envelope, wherein the phosphor blend includes aluminum nitride. The phosphor may be a wurtzite (hexagonal) crystalline structure Al.sub.(1-x)M.sub.xN phosphor, where M may be drawn from beryllium, magnesium, calcium, strontium, barium, zinc, scandium, yttrium, lanthanum, cerium, praseodymium, europium, gadolinium, terbium, ytterbium, bismuth, manganese, silicon, germanium, tin, boron, or gallium is synthesized to include dopants to control its luminescence under ultraviolet excitation. The disclosed Al.sub.(1-x)M.sub.xN:Mn phosphor provides bright orange-red emission, comparable in efficiency and spectrum to that of the standard orange-red phosphor used in fluorescent lighting, Y.sub.2O.sub.3:Eu. Furthermore, it offers excellent lumen maintenance in a fluorescent lamp, and does not utilize "critical rare earths," minimizing sensitivity to fluctuating market prices for the rare earth elements.

Optimal steel thickness combined with computed radiography for portal imaging of nasopharyngeal cancer patients

International Nuclear Information System (INIS)

Wu Shixiu; Jin Xiance; Xie Congying; Cao Guoquan

2005-01-01

The poor image quality of conventional metal screen-film portal imaging system has long been of concern, and various methods have been investigated in an attempt to enhance the quality of portal images. Computed radiography (CR) used in combination with a steel plate displays image enhancement. The optimal thickness of the steel plate had been studied by measuring the modulation transfer function (MTF) characteristics. Portal images of nasopharyngeal carcinoma patients were taken by both a conventional metal screen-film system and this optimal steel and CR plate combination system. Compared with a conventional metal screen-film system, the CR-metal screen system achieves a much higher image contrast. The measured modulation transfer function (MTF) of the CR combination is greater than conventional film-screen portal imaging systems and also results in superior image performance, as demonstrated by receiver operator characteristic (ROC) analysis. This optimal combination steel CR plate portal imaging system is capable of producing high contrast portal images conveniently

Uranium extraction from phosphoric acid

International Nuclear Information System (INIS)

Lounis, A.

1983-05-01

A study has been carried out for the extraction of uranium from phosphoric acid produced in Algeria. First of all, the Algerian phosphoric acid produced in Algeria by SONATRACH has been characterised. This study helped us to synthesize a phosphoric acid that enabled us to pass from laboratory tests to pilot scale tests. We have then examined extraction and stripping parameters: diluent, DZEPHA/TOPO ratio and oxidising agent. The laboratory experiments enabled us to set the optimum condition for the choice of diluent, extractant concentration, ratio of the synergic mixture, oxidant concentration, redox potential. The equilibrium isotherms lead to the determination of the number of theoretical stages for the uranium extraction and stripping of uranium, then the extraction from phosphoric acid has been verified on a pilot scale (using a mixer-settler)

Computed radiography dose optimization in pediatric patients

International Nuclear Information System (INIS)

Juste, B.; Verdu, G.; Tortosa, R.; Villaescusa, J.I.

2008-01-01

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

Phosphors for X-ray intensification screens

International Nuclear Information System (INIS)

Rebatin, J.G.

1980-01-01

An improved rare earth oxyhalide phosphor for x-ray intensification screens is described. The phosphors, of formula LnOX.T where Ln = La or Gd, X = Cl or Br and T = Tm or Tb, are mixed with a small amount of a trivalent antimony compound. The addition of antimony overcomes ageing due to attack by atmospheric moisture and renders the phosphor freeflowing so that dispersions can be readily made. Preferably the phosphor is washed with an aqueous solution of the antimony compound and the compound is the fluoride, chloride or butoxide, or potassium antimony tartrate. (U.K.)

A methodology for radiological accidents analysis in industrial gamma radiography

International Nuclear Information System (INIS)

Silva, F.C.A. da.

1990-01-01

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

Development of ''SonialvisionSafireII'' system with a new digital radiography device

International Nuclear Information System (INIS)

Sano, Takayuki; Okumura, Takeshi; Sakai, Takihito; Fujiwara, Masashi; Toyoda, Toshihide

2007-01-01

We released the world's first X-TV system equipped with a 17 inch direct conversion type flat panel X-ray detector (FPD) ''Safire'' in an radiofrequency (RF) table in 2004. Our latest X-TV system, called SonialvisionSafireII, incorporates the digital radiography device and the high voltage generator both of which were newly developed to take better advantage of the characteristics of the FPD. The following are the features of the latest system: Image acquisition and processing with the original matrix of FPD (up to 2880 x 2880 matrix with a 17-inch field of view (FOV)), High-speed radiography in serial acquisition mode (up to 15 fps) and tomosynthesis acquisition mode (up to 30 fps), Operationally improved digital radiography device using a general-purpose personal computer. (author)

Real-time radiography

International Nuclear Information System (INIS)

Bossi, R.H.; Oien, C.T.

1981-01-01

Real-time radiography is used for imaging both dynamic events and static objects. Fluorescent screens play an important role in converting radiation to light, which is then observed directly or intensified and detected. The radiographic parameters for real-time radiography are similar to conventional film radiography with special emphasis on statistics and magnification. Direct-viewing fluoroscopy uses the human eye as a detector of fluorescent screen light or the light from an intensifier. Remote-viewing systems replace the human observer with a television camera. The remote-viewing systems have many advantages over the direct-viewing conditions such as safety, image enhancement, and the capability to produce permanent records. This report reviews real-time imaging system parameters and components

Practical evaluation of clinical image quality (4). Determination of image quality in digital radiography system

International Nuclear Information System (INIS)

Katayama, Reiji

2016-01-01

Recently, for medical imaging, digital radiography systems are widely used in clinical practices. However, a study in the past reported that a patient radiation exposure level by digital radiography is in fact not lower than that by analog radiography system. High level of attention needs to be paid for over-exposure when using the conventional analog radiography with a screen and a film, as it results in high density of the film. However, for digital radiography systems, since the automatic adjusting function of image density is equipped with them, no attention for radiation dose need to be paid. Thus technologists tend to be careless and results in higher chance for over-exposure. Current digital radiography systems are high-performance in the image properties and capable of patient dose reduction. Especially, the image quality of the flat panel detector system is recognized, higher than that of the computed radiography system by imaging plates, in both objective and subjective evaluations. Therefore, we technologists are responsible for optimizing the balance between the image quality of the digital radiogram and the radiation dose required for each case. Moreover, it is also required for us as medical technologists to make effective use of such evaluation result of medical images for patients. (author)

Radiography using californium-252 neutron sources

International Nuclear Information System (INIS)

Ray, J.W.

1975-01-01

The current status in the technology of neutron radiography using californium-252 neutron sources is summarized. Major emphasis is on thermal neutron radiography since it has the widest potential applicability at the present time. Attention is given to four major factors which affect the quality and useability of thermal neutron radiography: source neutron thermalization, neutron beam extraction geometry, neutron collimator dimensions, and neutron imaging methods. Each of these factors has a major effect on the quality of the radiographs which are obtained from a californium source neutron radiography system and the exposure times required to obtain the radiographs; radiograph quality and exposure time in turn affect the practicality of neutron radiography for specific nondestructive inspection applications. A brief discussion of fast neutron radiography using californium-252 neutron sources is also included. (U.S.)

Dental radiography

International Nuclear Information System (INIS)

Shekhdar, J.

1993-01-01

Dental radiography must comply with the same regulations with which conventional radiography complies. Radiation doses to individual patients are low but, because of the large number of patients X-rayed, the collective dose to the population is not negligible. Care in siting and regular maintenance of the equipment will reduce doses to both staff and patients. To produce X-ray films with a good image quality using a low radiation dose requires attention to film processing; this is often a neglected area. (Author)

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

International Nuclear Information System (INIS)

Kishimoto, M.; Sumiya, T.; Lee, K.J.

2010-01-01

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

Double beam neutron radiography facility

International Nuclear Information System (INIS)

Domanus, J.C.

1977-09-01

The DR1 reactor at Risoe is used as a neutron source for neutron radiography. In the double-beam neutron radiography facility a neutron flux of an intensity of 1.4 and 1.8 x 10 6 n. cm -2 . s -1 reaches the object to be radiographed. The transport and exposure container used for neutron radiography of irradiated nuclear fuel rods is described, and the exposure technique and procedure are reviewed. The mode by which single neutron radiographs are assembled and assessed is described. This report will be published in the ''Neutron Radiography Newsletter''. (author)

Distribution of root exudates and mucilage in the rhizosphere: combining 14C imaging with neutron radiography

Science.gov (United States)

Holz, Maire; Carminati, Andrea; Kuzyakov, Yakov

2015-04-01

Water and nutrients will be the major factors limiting food production in future. Plant roots employ various mechanisms to increase the access to limited soil resources. Low molecular weight organic substances released by roots into the rhizosphere increase nutrient availability by interactions with microorganisms, while mucilage improves water availability under low moisture conditions. Though composition and quality of these substances have intensively been investigated, studies on the spatial distribution and quantification of exudates in soil are scarce. Our aim was to quantify and visualize root exudates and mucilage distribution around growing roots using neutron radiography and 14C imaging depending on drought stress. Plants were grown in rhizotrons well suited for neutron radiography and 14C imaging. Plants were exposed to various soil water contents experiencing different levels of drought stress. The water content in the rhizosphere was imaged during several drying/wetting cycles by neutron radiography. The radiographs taken a few hours after irrigation showed a wet region around the root tips showing the allocation and distribution of mucilage. The increased water content in the rhizosphere of the young root segments was related to mucilage concentrations by parameterization described in Kroener et al. (2014). In parallel 14C imaging of root after 14CO2 labeling of shoots (Pausch and Kuzyakov 2011) showed distribution of rhizodeposits including mucilage. Three days after setting the water content, plants were labeled in 14CO2 atmosphere. Two days later 14C distribution in soil was imaged by placing a phosphor-imaging plate on the rhizobox. To quantify rhizodeposition, 14C activity on the image was related to the absolute 14C activity in the soil and root after destructive sampling. By comparing the amounts of mucilage (neutron radiography) with the amount of total root derived C (14C imaging), we were able to differentiate between mucilage and root

Quality comparison between DEF-10 digital image from simulation technique and Computed Tomography (CR) technique in industrial radiography

International Nuclear Information System (INIS)

Siti Nur Syatirah Ismail

2012-01-01

The study was conducted to make comparison of digital image quality of DEF-10 from the techniques of simulation and computed radiography (CR). The sample used is steel DEF-10 with thickness of 15.28 mm. In this study, the sample is exposed to radiation from X-ray machine (ISOVOLT Titan E) with certain parameters. The parameters used in this study such as current, volt, exposure time and distance are specified. The current and distance of 3 mA and 700 mm respectively are specified while the applied voltage varies at 140, 160, 180 and 200 kV. The exposure time is reduced at a rate of 0, 20, 40, 60 and 80 % for each sample exposure. Digital image of simulation produced from aRTist software whereas digital image of computed radiography produced from imaging plate. Therefore, both images were compared qualitatively (sensitivity) and quantitatively (Signal to-Noise Ratio; SNR, Basic Spatial Resolution; SRb and LOP size) using Isee software. Radiographic sensitivity is indicated by Image Quality Indicator (IQI) which is the ability of the CR system and aRTist software to identify IQI of wire type when the time exposure is reduced up to 80% according to exposure chart ( D7; ISOVOLT Titan E). The image of the thinnest wire diameter achieved by radiograph from simulation and CR are the wire numbered 7 rather than the wire numbered 8 required by the standard. In quantitative comparison, this study shows that the SNR values decreases with reducing exposure time. SRb values increases for simulation and decreases for CR when the exposure time decreases and the good image quality can be achieved at 80% reduced exposure time. The high SNR and SRb values produced good image quality in CR and simulation techniques respectively. (author)

Method of preparing a thermoluminescent phosphor

Science.gov (United States)

Lasky, Jerome B.; Moran, Paul R.

1979-01-01

A thermoluminescent phosphor comprising LiF doped with boron and magnesium is produced by diffusion of boron into a conventional LiF phosphor doped with magnesium. Where the boron dopant is made to penetrate only the outer layer of the phosphor, it can be used to detect shallowly penetrating radiation such as tritium beta ays in the presence of a background of more penetrating radiation.

Morphology of the pelvis and hind limb of the red panda (Ailurus fulgens) evidenced by gross osteology, radiography and computed tomography.

Science.gov (United States)

Makungu, M; du Plessis, W M; Groenewald, H B; Barrows, M; Koeppel, K N

2015-12-01

The red panda (Ailurus fulgens) is a quadrupedal arboreal animal primarily distributed in the Himalayas and southern China. It is a species commonly kept in zoological collections. This study was carried out to describe the morphology of the pelvis and hind limb of the red panda evidenced by gross osteology, radiography and computed tomography as a reference for clinical use and identification of skeletons. Radiography of the pelvis and right hind limb was performed in nine and seven animals, respectively. Radiographic findings were correlated with bone specimens from three adult animals. Computed tomography of the torso and hind limb was performed in one animal. The pelvic bone had a wide ventromedial surface of the ilium. The trochlea of the femur was wide and shallow. The patella was similar to that seen in feline species. The medial fabella was not seen radiographically in any animal. The cochlea grooves of the tibia were shallow with a poorly defined intermediate ridge. The trochlea of the talus was shallow and presented with an almost flattened medial ridge. The tarsal sesamoid bone was always present. The lateral process of the base of the fifth metatarsal (MT) bone was directed laterally. The MT bones were widely spaced. The morphology of the pelvis and hind limb of the red panda indicated flexibility of the pelvis and hind limb joints as an adaptation to an arboreal quadrupedal lifestyle. © 2014 Blackwell Verlag GmbH.

Magnification radiography

International Nuclear Information System (INIS)

Genant, H.K.; Resnick, D.

1988-01-01

The relative clinical value of magnification compared with conventional radiography for skeletal applications is presented qualitatively. The presentation is based on the authors' experience with over 25,000 cases in which magnification has been used. For most areas in which magnification (optical or geometric) proves useful, subtle abnormalities of clinical importance are present at bone surfaces or at host-lesion interfaces. This is particularly true for arthritis and metabolic and infectious disorders of bone. In additional instances, serial assessment of the progression of disease or its response to therapy is enhanced by magnification. When gross abnormalities are present, as in most instances of trauma and bone dysplasia, the findings are obvious on conventional radiography, and magnification is not necessary. Thus, the magnification techniques appear to provide important diagnostic information, depending upon the anatomic part that is studied and the clinical question that is posed. It is also apparent that the demonstration of subtle skeletal abnormalities to clinical colleagues for educational purposes is greatly enhanced by magnification radiography

Bone X-Ray (Radiography)

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Full Text Available ... are the limitations of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray ( ... leg (shin), ankle or foot. top of page What are some common uses of the procedure? A ...

The Influence of Phosphor and Binder Chemistry on the Aging Characteristics of Remote Phosphor Products

Energy Technology Data Exchange (ETDEWEB)

Davis, Lynn; Yaga, Robert; Lamvik, Michael; Mills, Karmann; Fletcher, B.

2017-06-30

The influence of phosphor and binder layer chemistries on the lumen maintenance and color stability of remote phosphor disks were examined using wet high-temperature operational lifetime testing (WHTOL). As part of the experimental matrix, two different correlated color temperature (CCT) values, 2700 K and 5000 K, were studied and each had a different binder chemistry. The 2700 K samples used a urethane binder whereas the 5000 K samples used an acrylate binder. Experimental conditions were chosen to enable study of the binder and phosphor chemistries and to minimize photo-oxidation of the polycarbonate substrate. Under the more severe WHTOL conditions of 85°C and 85% relative humidity (RH), absorption in the binder layer significantly reduced luminous flux and produced a blue color shift. The milder WHTOL conditions of 75°C and 75% RH, resulted in chemical changes in the binder layer that may alter its index of refraction. As a result, lumen maintenance remained high, but a slight yellow shift was found. The aging of remote phosphor products provides insights into the impact of materials on the performance of phosphors in an LED lighting system.

Review of medical radiography and tomography with proton beams

Science.gov (United States)

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.

Comparison of plain radiography, conventional tomography, and computed tomography in detecting intrathoracic lymph node metastases from lung carcinoma

International Nuclear Information System (INIS)

Osborne, D.R.; Korobkin, M.; Ravin, C.E.

1982-01-01

Forty-two patients with T2 bronchogenic carcinoma were evaluated with plain radiography, conventional 55 0 oblique hilar and anteroposterior mediastinal tomography, and computed tomography (CT) to compare their accuracy in assessing mediastinal and hilar nodal metastases. Definitive staging was achieved by thoracotomy and histopathological evaluation of resected specimens. All modalities demonstrated about the same accuracy, however, in the 25 patients with hilar and/or mediastinal lymphadenopathy, CT of the mediastinum was more sensitive but not more specific than the other two and conventional tomography was no more accurate than CT for hilar evaluation. Overall, no technicue was accurate enough for routine staging; their value may lie in directing biopsy or in treatment planning in patients with inoperable disease

A Comparison of Plain Radiography with Computer Tomography in Determining Coronal and Sagittal Alignments following Total Knee Arthroplasty

Directory of Open Access Journals (Sweden)

Solayar GN

2017-07-01

Full Text Available INTRODUCTION: Optimal coronal and sagittal component positioning is important in achieving a successful outcome following total knee arthroplasty (TKA. Modalities to determine post-operative alignment include plain radiography and computer tomography (CT imaging. This study aims to determine the accuracy and reliability of plain radiographs in measuring coronal and sagittal alignment following TKA. MATERIALS AND METHODS: A prospective, consecutive study of 58 patients undergoing TKA was performed comparing alignment data from plain radiographs and CT imaging. Hip- knee-angle (HKA, sagittal femoral angle (SFA and sagittal tibial angle (STA measurements were taken by two observers from plain radiographs and compared with CT alignment. Intra- and inter-observer correlation was calculated for each measurement. RESULTS: Intra-observer correlation was excellent for HKA (r>0.89 with a mean difference of 0.95 and STA (r>0.8 compared to SFA (r=0.5. When comparing modalities (radiographs vs CT, HKA estimations for both observers showed the least maximum and mean differences while SFA observations were the least accurate. CONCLUSION: Radiographic estimation of HKA showed excellent intra- and inter-observer correlation and corresponds well with CT imaging. However, radiographic estimation of sagittal plane alignment was less reliably measured and correlated less with CT imaging. Plain radiography was found to be inferior to CT for estimation of biplanar prosthetic alignment following TKA.

Twenty-degree-tilt radiography for evaluation of lateral humeral condylar fracture in children

International Nuclear Information System (INIS)

Imada, Hideaki; Tanaka, Ryuji; Itoh, Yohei; Kishi, Kazuhiko

2010-01-01

To investigate the efficacy of '20 -tilt anteroposterior (A-P) radiography' in the assessment of lateral condylar fractures of the distal humerus. Eighteen children with lateral humeral condylar fractures were studied. Every child underwent conventional A-P and lateral radiography, and six children underwent multi-detector computed tomography (MDCT). For the investigation of 20 -tilt radiography, ten children with lateral humeral condylar fractures had conventional and 20 -tilt A-P and lateral radiography both preoperatively and postoperatively. Fragment dislocation was measured at the lateral and medial margins of the fracture on both the conventional A-P and 20 -tilt A-P radiographs. The lateral condylar fragment was triangular and was most prominent posteriorly. The fracture line was typically tilted approximately 20 to a reference line perpendicular to the long axis of the humerus in the lateral view. The extent of dislocation at the lateral and medial margins of the fracture site by 20 -tilt A-P radiography (9.3 ± 3.6 mm and 5.6 ± 2.5 mm) was significantly wider than that measured by the conventional method (6.8 ± 4.1 mm and 2.0 ± 1.5 mm), which may influence treatment. Twenty-degree-tilt A-P radiography may more precisely demonstrate fragment dislocation than standard radiographs and may influence patient treatment. (orig.)

Transitioning to digital radiography

Energy Technology Data Exchange (ETDEWEB)

Miranda, F., E-mail: Francisco.Miranda@pwc.ca [Pratt & Whitney Canada, Longueuil, Quebec (Canada)

2015-09-15

This article provides insight on the technical and business considerations necessary to implement or to transition to digital radiography Continued refinements in digital radiography technology have resulted in significant improvements in image quality and detectability of indications. These improvements have resulted in the acceptance of the technology by users and aerospace primes for final product inspection and disposition. Digital radiography has also been identified as an interesting cost reduction initiative with the potential of providing gains in productivity through increased throughput and decreased inspection lead-times and resulting costs. (author)

Recent developments in radiography

International Nuclear Information System (INIS)

Berger, Harold

1982-01-01

Advances in radiography are reviewed and eighty-one references are cited to provide additional information. The review includes information on x-ray sources in terms of output, portability and imaging geometry and detectors in terms of films and screens, electrostatic methods, real-time techniques and solid state devices. Inspection methods utilizing radiations other than x-rays, neutrons and charged particles, expand the inspection problems suitable for radiography. Techniques such as tomography, digital radiography and image enhancement are described. Tomography, in particular, provides excellent capability to characterize materials and discontinuities

Digital detection systems for projection radiography

International Nuclear Information System (INIS)

Schulz, R.F.

2001-01-01

This article gives a survey of digital X-ray detection systems for projection radiography. The different principles are compared and some general characteristics are derived. The basic conversion mechanisms in the absorption layers are described. The basic principles of solid state X-ray detectors and their general characteristics are elucidated as well as some similarities with detectors for computed tomography. Some important application and system aspects are considered. An outlook on further possible developments in this field is given. (orig.) [de

Consumption of Pt anode in phosphoric acid

Energy Technology Data Exchange (ETDEWEB)

Kamiya, N.; Urata, K.; Motohira, N.; Ota, K. [Yokohama National University, Yokohama (Japan)

1997-12-05

Consumption of Pt anode was investigated in phosphoric acid of various concentration. In 30-70wt% phosphoric acid, Pt dissolved at the rate of 19{mu}gcm{sup -2}h{sup -1}. On the other hand, in 85 wt% phosphoric acid, the amount increased to 0.91 mgcm{sup -2}h{sup -1} which is ca. 180 and 1800 times as much as in 1M sulfuric acid and 1M alkaline solution, respectively. In the diluted phosphoric acid solution, the Pt surface was covered with Pt oxides during the electrolysis, which would prevent the surface from corrosion. However, in the concentrated phosphoric acid, no such oxide surface was observed. Concentrated phosphoric acid might form stable complex with Pt species, therefore the uncovered bare Pt surface is situated in the serious corrosion condition under the high overvoltage and Pt would dissolve into the solution directly instead of forming the Pt oxides. 11 refs., 9 figs., 1 tab.

neutron radiography. Report prepared from contributions by members of the MOD Working Party on Neutron Radiography

International Nuclear Information System (INIS)

Halmshaw, R.

1977-03-01

Radiography with thermal or cold neutrons has some special advantages over X-rays and gamma rays, and some facilities for neutron radiography exist in the Ministry of Defence. This report gives a brief and simple description of the technique, its advantages and disadvantages, and is illustrated with a number of Ordnance applications taken from MOD work, to show examples where neutron radiographs provided extra important information not available from X- or gamma radiography. The facilities available in the UK for neutron radiography are listed. (author)

Computed vs. conventional radiography for detecting fatigue cracks in riveted lap joints of aeronautical grade hybrid fiber-metal laminate Glare

International Nuclear Information System (INIS)

Tarpani, J.R.; Hideki Shinohara, A.; Da Silva, R.R.; Do Val Lacerda, N.

2007-01-01

This study aimed at assessing the capability of three different radiographic approaches (two computed or digital, and one conventional or analogous) for imaging fatigue cracks in riveted lap joints of composite fiber-metal laminate Glare. These structural joints are unique in the sense that fatigue cracks develop mainly at the faying surfaces of Glare sheets, so that visual detection is largely prevented and nondestructive inspection becomes mandatory. For this purpose, a round-robin programme comprising several industrial and research centers that employ X-ray radiography routinely to inspect high-demanding equipments, components and structures was conducted. (authors)

Process for recovering a uranium containing concentrate and purified phosphoric acid from a wet process phosphoric acid containing uranium

International Nuclear Information System (INIS)

Weterings, C.A.M.; Janssen, J.A.

1985-01-01

A process is claimed for recovering from a wet process phosphoric acid which contains uranium, a uranium containing concentrate and a purified phosphoric acid. The wet process phosphoric acid is treated with a precipitant in the presence of a reducing agent and an aliphatic ketone

Process for recovering a uranium containing concentrate and purified phosphoric acid from a wet process phosphoric acid containing uranium

Energy Technology Data Exchange (ETDEWEB)

Weterings, C.A.M.; Janssen, J.A.

1985-04-30

A process is claimed for recovering from a wet process phosphoric acid which contains uranium, a uranium containing concentrate and a purified phosphoric acid. The wet process phosphoric acid is treated with a precipitant in the presence of a reducing agent and an aliphatic ketone.

Quality assurance in digital radiography

International Nuclear Information System (INIS)

Busch, H.P.; Lehmann, K.J.

1989-01-01

At present, there is no standard way of evaluating performance characteristics of digital radiography systems. Continuous measurements of performance parameters are necessary in order to obtain images of high quality. Parameters of quality assurance in digital radiography, which can be evaluated with simple, quick methods, are spatial resolution, low-contrast detectability, dynamic range and exposure dose. Spatial resolution was determined by a lead bar pattern, whereas the other parameters were measured by commercially available phantoms. Performance measurements of 10 digital subtraction angiography (DSA) units and one digital radiography system for unsubtracted digital radiography were assessed. From these results, recommendations for performance parameter levels will be discussed. (author)

Guidelines for anti-scatter grid use in pediatric digital radiography.

Science.gov (United States)

Fritz, Shannon; Jones, A Kyle

2014-03-01

Pediatric radiography presents unique challenges in balancing image quality and patient dose. Removing the anti-scatter grid reduces patient dose but also reduces image contrast. The benefit of using an anti-scatter grid decreases with decreasing patient size. To determine patient thickness thresholds for anti-scatter grid use by comparing scatter-to-primary ratio for progressively thinner patients without a grid to the scatter-to-primary ratio for a standard adult patient with a grid. We used Solid Water™ phantoms ranging in thickness from 7 cm to 16 cm to simulate pediatric abdomens. The scatter-to-primary ratio without a grid was measured for each thickness at 60 kVp, 70 kVp and 80 kVp for X-ray fields of view (FOV) of 378 cm(2), 690 cm(2) and 1,175 cm(2) using indirect digital radiography (iDR) and computed radiography (CR). We determined thresholds for anti-scatter grid use by comparing the intersection of a fit of scatter-to-primary ratio versus patient thickness with a standard adult scatter-to-primary ratio measured for a 23-cm phantom thickness at 80 kVp with an anti-scatter grid. Dose area product (DAP) was also calculated. The scatter-to-primary ratio depended strongly on FOV and weakly on kVp; however DAP increased with decreasing kVp. Threshold thicknesses for grid use varied from 5 cm for a 14 × 17-cm FOV using iDR to 12 cm for an 8 × 10-cm FOV using computed radiography. Removing the anti-scatter grid for small patients reduces patient dose without a substantial increase in scatter-to-primary ratio when the FOV is restricted appropriately. Radiologic technologists should base anti-scatter grid use on patient thickness and FOV rather than age.

Selenium-based digital radiography of the cervical spine. Comparison with screen-film radiography for the depiction of anatomic details

International Nuclear Information System (INIS)

Ludwig, K.; Diederich, S.; Wormanns, D.; Link, T.M.; Lenzen, H.; Heindel, W.

2002-01-01

Purpose: To compare selenium-based digital radiography with conventional screen-film radiography of the cervical spine. Materials and Methods: In a prospective study X-ray images of the cervical spine were obtained in 25 patients using selenium-based digital radiography and conventional screen-film radiography. All images were clinically indicated. Selenium-based digital radiography and conventional screen-film radiography were used in a randomized order. Four radiologists independently evaluated all 50 examinations for the visibility of 76 anatomic details according to a five-level confidence scale (1=not visible, 5=very good visibility). From the evaluation of these anatomic details scores for the upper and middle cervical spine, the cervicothoracic junction and the cervical soft tissues were calculated. The scores for selenium-based digital radiography and conventional screen-film radiography were compared using Wilcoxon's signed rank test. Results: From a total of 15,200 observations (608 per patient) the following scores were calculated for selenium-based digital radiography and for screen-film radiography, respectively: Upper cervical spine 3.88 and 3.94; middle cervical spine 4.60 and 4.48; cervico-thoracic junction 3.64 and 2.62; cervical soft tissue 4.47 and 3.46. The differences between the last two scores were statistically significant (p [de

Radioisotopes - their applications in industrial radiography

International Nuclear Information System (INIS)

Rao, H.R.S.

1977-01-01

The nature of radioisotopes and their industrial applications with special reference to industrial radiography are outlined. The various aspects of industrial radiography such as source size, source containers, films, density of radiography, radiographic quality and applications are discussed in brief. (M.G.B.)

Radiogenic cancer induction associated with spinal radiography: a quantitative analysis

International Nuclear Information System (INIS)

Fickel, T.E.

1988-01-01

Computations of organ-specific radiation absorption by lung, breast, thyroid, active bone marrow and uterine tissues are used to rank sectional and full spine radiographic procedures according to their potentials for cancer induction. Assuming that the dose-effect relationship of radiation damage is linear and lacks a threshold effect, the prospective and retrospective carcinogenicities of commonly ordered spinal series are estimated. Cervical radiography is demonstrated to pose the least hazard to the patient, while full spine and lumbar (five views) procedures have the greatest. Organs most at risk as a result of spinal radiography are lung (thoracic and full spine), colon (lumbar and full spine), breast (thoracic and full spine), and prostate (full spine and lumbar)

Optimizing digital radiography of children

International Nuclear Information System (INIS)

Willis, Charles E.

2009-01-01

Pediatric projection imaging differs from imaging of the adult patient. Children are smaller, more radiosensitive, and less compliant than their adult counterparts. Their characteristics affect the way projection imaging is practiced and how dose is optimized. Computed radiography (CR) and digital radiography (DR) have been embraced by pediatric practitioners in order to reduce dose and improve image quality. Unfortunately, dose optimization with CR and DR has been hampered by a lack of definition of appropriate exposure levels, a lack of standardization in exposure factor feedback, and a lack of understanding of the fundamentals of CR and DR technology. The potential for over-exposure exists with both CR and DR. Both the Society for Pediatric Radiology and the American Association of Physicists in Medicine recognize the promise and shortcomings of CR and DR technology and have taken steps to join with manufacturers in improving the practice of CR and DR imaging. Although the risks inherent in pediatric projection imaging with CR and DR are low, efforts to reduce dose are worthwhile, so long as diagnostic quality is maintained. Long-standing recommendations for limiting radiation dose in pediatric projection imaging are still applicable to CR and DR.

Method of purifying phosphoric acid after solvent extraction

International Nuclear Information System (INIS)

Kouloheris, A.P.; Lefever, J.A.

1979-01-01

A method of purifying phosphoric acid after solvent extraction is described. The phosphoric acid is contacted with a sorbent which sorbs or takes up the residual amount of organic carrier and the phosphoric acid separated from the organic carrier-laden sorbent. The method is especially suitable for removing residual organic carrier from phosphoric acid after solvent extraction uranium recovery. (author)

Detection of simulated pulmonary nodules by single-exposure dual-energy computed radiography of the chest: effect of a computer-aided diagnosis system (Part 2)

International Nuclear Information System (INIS)

Kido, Shoji; Kuriyama, Keiko; Kuroda, Chikazumi; Nakamura, Hironobu; Ito, Wataru; Shimura, Kazuo; Kato, Hisatoyo

2002-01-01

Objective: To evaluate the performance of the computer-aided diagnosis (CAD) scheme on the detection of pulmonary nodules (PNs) in single-exposure dual-energy subtraction computed radiography (CR) images of the chest, and to evaluate the effect of this CAD scheme on radiologists' detectabilities. Methods and material: We compared the detectability by the CAD scheme with the detectability by 12 observers by using conventional CR (C-CR) and bone-subtracted CR (BS-CR) images of 25 chest phantoms with a low-contrast nylon nodule. Results: Both in the CAD scheme and for the observers, the detectability of BS-CR images was superior to that of C-CR images (P<0.005). The detection performance of the CAD scheme was equal to that of the observers. The nodules detected by the CAD did not necessarily coincide with those by the observers. Thus, if observers can use the results of the CAD system as a 'second opinion', their detectabilities increase. Conclusion: The CAD system for detection of PNs in the single-exposure dual-energy subtraction method is promising for improving radiologists' detectabilities of PNs

Euratom Neutron Radiography Working Group

DEFF Research Database (Denmark)

Domanus, Joseph Czeslaw

1986-01-01

reactor fuel as well as establish standards for radiographic image quality of neutron radiographs. The NRWG meets once a year in each of the neutron radiography centers to review the progress made and draw plans for the future. Besides, ad-hoc sub-groups or. different topics within the field of neutron......In 1979 a Neutron Radiography Working Group (NRWG) was constituted within Buratom with the participation of all centers within the European Community at which neutron facilities were available. The main purpose of NRWG was to standardize methods and procedures used in neutron radiography of nuclear...... radiography are constituted. This paper reviews the activities and achievements of the NRWG and its sub-groups....

Practical considerations and effects of metallic screen fluorescence and backscatter control in gamma computed radiography

International Nuclear Information System (INIS)

Mango, Steven

2016-01-01

It is a fairly common misconception that the role of metallic screens used with computed radiography is primarily that of scatter control, and that any amplification of the image signal is minimal. To the contrary, this paper shows how the physical interaction between gamma rays and front metallic screens can yield a significant boost in signal and whether that increased signal is, in fact, beneficial or detrimental to image quality. For rear metallic screens, this signal boost is differentiated from backscatter, and image quality considerations should be more carefully thought out because of the separation between the screen and the imaging layer provided by the imaging plate support. Various physical interactions are explained, and a series of practical experiments show the various changes in signal level and image quality with various thicknesses of lead and copper screens. Recommendations are made for the configuration of the imaging plate and screens for optimum image quality and for the control and monitoring of scatter.

Fracture healing: direct magnification versus conventional radiography

International Nuclear Information System (INIS)

Link, T.M.; Kessler, T.; Lange, T.; Overbeck, J.; Fiebich, M.; Peters, P.E.

1994-01-01

The aim of the study was to evaluate the potential of magnification radiography in diagnosing fracture healing and assessing its complications. Seventy-three patients with fractures or who had undergone osteotomy were radiographed with both conventional (non-magnified) and magnification (5-fold) techniques. Since 10 patients were radiographed twice and 1 three times, 83 radiographs using each technique were obtained. All radiographs were analysed and the findings correlated with the patients' follow-up studies. The microfocal X-ray unit used for magnification radiography had a focal spot size of 20-130 μm. As an imaging system, digital luminescence radiography was employed with magnification, while normal film-screen systems were used with conventional radiography. Magnification radiography proved superior to conventional radiography in 47% of cases: endosteal and periosteal callus formations were seen earlier and better in 26 cases, and osseous union could be evaluated with greater certainty in 33 cases. In 49% of cases magnification radiography was equal and in 4% inferior to conventional radiography. Additionally an ''inter-observer analysis'' was carried out. Anatomical and pathological structures were classified into one of four grades. Results were significantly (P < 0.01) better using magnification radiography. We conclude that the magnification technique is a good method for monitoring fracture healing in its early stages. (orig.)

Studies on the correlation between photograph condition and image quality on computed radiography

International Nuclear Information System (INIS)

Ding Wenhong; Zhang Weimin; Ding Xingfa

2007-01-01

Objective: To evaluate how to use reasonably the combination of exposure dose and speed class on the base of imaging quality on computed radiography (CB). Methods: Based on threshold contrast- detail detectability (TCCD)technique, phantom TO. 16 photography was done with 55, 65 and 75 kV, and combination with three kinds of different exposure dose and speed class respectively. Three radiologists scored each image sequence using double blind method and calculated the threshold detection index (H T ). The imaging quality of knee joint, chest and lumbarspine was also evaluated by these radiologists on the base of diagnostic quality and the different combination of exposure close and speed class. Results: Exposure dose was increased by using lower kV value, and Hr value was increased by lower exposure grade rather than higher kV value. Exposure dose was decreased obviously and speed class was increased in the good contrast location at the same kV value. Conclusions: Based on the demand of diagnostic quality and the contrast of the checked location, the speed class should be carefully selected to decrease the radiation dose exposure to patients, without any decrease of the diagnostic quality. (authors)

The application of image processing to the detection of corrosion by radiography

International Nuclear Information System (INIS)

Packer, M.E.

1979-02-01

The computer processing of digitised radiographs has been investigated with a view to improving x-radiography as a method for detecting corrosion. Linearisation of the image-density distribution in a radiograph has been used to enhance information which can be attributed to corrosion, making the detection of corrosion by radiography both easier and more reliable. However, conclusive evidence has yet to be obtained that image processing can result in the detection of corrosion which was not already faintly apparent on an unprocessed radiograph. A potential method has also been discovered for analysing the history of a corrosion site

First experience with digital radiography

International Nuclear Information System (INIS)

Buchmann, F.

1987-01-01

The digital radiogram is explained, its advantages being the various possibilities of image processing, loss-free transmission, recording and storage capabilities, and in special cases, prompt availability of processed images. Digital subtraction angiography (DSA) and the high-resolution method of digital, luminescent radiography, which replaced the conventional film-foil radiography, are explained as the first developments for the introduction of digital radiography, which today already is an applicable technique. (orig./MG) [de

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

Science.gov (United States)

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.

Calculation of the Cardiothoracic Ratio from Portable Anteroposterior Chest Radiography

Science.gov (United States)

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 chest AP with an available previous chest PA. This might help physicians detect congestive cardiomegaly for patients undergoing portable chest AP. PMID:22065900

A survey of sub-specialty preferences of radiography students of the University of Lagos, Nigeria

Directory of Open Access Journals (Sweden)

E T Namah

2013-01-01

Full Text Available Background: Technological advances and computing have expanded both the scope and capacity of diagnostic medical imaging (the radiography profession. This has created many diverse imaging modalities which in turn, have culminated in different sub-specialties in the profession. Objective: The aims of the study were to determine the level of awareness of imaging sub-specialties, preferred sub specialties and reasons for preferences of sub-specialties in senior level radiography students of the University of Lagos. Methods: The study was a prospective cross-sectional survey. Consents were obtained before the students were recruited for the study. Data Collection and Analysis: A questionnaire semi-structured in line with objectives of the study was used in data collection. A computer software Epi Info version 3.3 was used to analyze data while results were expressed as percentages of responses and were presented in tables and pie charts. Results : Greater than 90% showed awareness of sub-specialties in the radiography profession whereas 35% preferred ultrasonography to other sub-specialties. The least preferred sub-specialty was conventional radiography (4.3%. Remuneration (73.3% and less physical exertion (73.3% were major attractors to preferred sub-specialties whereas concerns over radiation hazard were major detractors (58.3%. Conclusion : Awareness of sub-specialties in the radiography profession was high amongst students studied. Furthermore, ultrasonography was the most preferred sub-specialty among the respondents. Remuneration was the main attractor to sub-specialties whereas fears over effects of ionizing radiation were the major detractors to some sub-specialties.

Rhinoceros feet step out of a rule-of-thumb: a wildlife imaging pioneering approach of synchronized computed tomography-digital radiography.

Directory of Open Access Journals (Sweden)

Gabriela Galateanu

Full Text Available Currently, radiography is the only imaging technique used to diagnose bone pathology in wild animals situated under "field conditions". Nevertheless, while chronic foot disease in captive mega-herbivores is widely reported, foot radiographic imaging is confronted with scarcity of studies. Numerous hindrances lead to such limited numbers and it became very clear that the traditional perspective on bone imaging in domestic animals based on extensive studies and elaborated statistical evaluations cannot be extrapolated to their non-domestic relatives. For these reasons, the authors initiated a multi-modality imaging study and established a pioneering approach of synchronized computed tomography (CT and digital radiography (DR, based on X-ray projections derived from three-dimensional CT reconstructed images. Whereas this approach can be applied in any clinical field, as a case of outstanding importance and great concern for zoological institutions, we selected foot bone pathologies in captive rhinoceroses to demonstrate the manifold applications of the method. Several advances were achieved, endowing the wildlife clinician with all-important tools: prototype DR exposure protocols and a modus operandi for foot positioning, advancing both traditional projections and, for the first-time, species-related radiographic views; assessment of radiographic diagnostic value for the whole foot and, in premiere, for each autopodial bone; together with additional insights into radiographic appearance of bone anatomy and pathology with a unique, simultaneous CT-DR correlation. Based on its main advantages in availing a wide range of keystone data in wildlife imaging from a limited number of examined subjects and combining advantages of CT as the golden standard method for bone diseases' diagnostic with DR's clinical feasibility under field conditions, synchronized CT-DR presents a new perspective on wildlife's health management. With this we hope to provide

Rhinoceros feet step out of a rule-of-thumb: a wildlife imaging pioneering approach of synchronized computed tomography-digital radiography.

Science.gov (United States)

Galateanu, Gabriela; Hermes, Robert; Saragusty, Joseph; Göritz, Frank; Potier, Romain; Mulot, Baptiste; Maillot, Alexis; Etienne, Pascal; Bernardino, Rui; Fernandes, Teresa; Mews, Jurgen; Hildebrandt, Thomas Bernd

2014-01-01

Currently, radiography is the only imaging technique used to diagnose bone pathology in wild animals situated under "field conditions". Nevertheless, while chronic foot disease in captive mega-herbivores is widely reported, foot radiographic imaging is confronted with scarcity of studies. Numerous hindrances lead to such limited numbers and it became very clear that the traditional perspective on bone imaging in domestic animals based on extensive studies and elaborated statistical evaluations cannot be extrapolated to their non-domestic relatives. For these reasons, the authors initiated a multi-modality imaging study and established a pioneering approach of synchronized computed tomography (CT) and digital radiography (DR), based on X-ray projections derived from three-dimensional CT reconstructed images. Whereas this approach can be applied in any clinical field, as a case of outstanding importance and great concern for zoological institutions, we selected foot bone pathologies in captive rhinoceroses to demonstrate the manifold applications of the method. Several advances were achieved, endowing the wildlife clinician with all-important tools: prototype DR exposure protocols and a modus operandi for foot positioning, advancing both traditional projections and, for the first-time, species-related radiographic views; assessment of radiographic diagnostic value for the whole foot and, in premiere, for each autopodial bone; together with additional insights into radiographic appearance of bone anatomy and pathology with a unique, simultaneous CT-DR correlation. Based on its main advantages in availing a wide range of keystone data in wildlife imaging from a limited number of examined subjects and combining advantages of CT as the golden standard method for bone diseases' diagnostic with DR's clinical feasibility under field conditions, synchronized CT-DR presents a new perspective on wildlife's health management. With this we hope to provide veterinary clinicians

Rhinoceros Feet Step Out of a Rule-of-Thumb: A Wildlife Imaging Pioneering Approach of Synchronized Computed Tomography-Digital Radiography

Science.gov (United States)

Saragusty, Joseph; Göritz, Frank; Potier, Romain; Mulot, Baptiste; Maillot, Alexis; Etienne, Pascal; Bernardino, Rui; Fernandes, Teresa; Mews, Jurgen; Hildebrandt, Thomas Bernd

2014-01-01

Currently, radiography is the only imaging technique used to diagnose bone pathology in wild animals situated under “field conditions”. Nevertheless, while chronic foot disease in captive mega-herbivores is widely reported, foot radiographic imaging is confronted with scarcity of studies. Numerous hindrances lead to such limited numbers and it became very clear that the traditional perspective on bone imaging in domestic animals based on extensive studies and elaborated statistical evaluations cannot be extrapolated to their non-domestic relatives. For these reasons, the authors initiated a multi-modality imaging study and established a pioneering approach of synchronized computed tomography (CT) and digital radiography (DR), based on X-ray projections derived from three-dimensional CT reconstructed images. Whereas this approach can be applied in any clinical field, as a case of outstanding importance and great concern for zoological institutions, we selected foot bone pathologies in captive rhinoceroses to demonstrate the manifold applications of the method. Several advances were achieved, endowing the wildlife clinician with all-important tools: prototype DR exposure protocols and a modus operandi for foot positioning, advancing both traditional projections and, for the first-time, species-related radiographic views; assessment of radiographic diagnostic value for the whole foot and, in premiere, for each autopodial bone; together with additional insights into radiographic appearance of bone anatomy and pathology with a unique, simultaneous CT-DR correlation. Based on its main advantages in availing a wide range of keystone data in wildlife imaging from a limited number of examined subjects and combining advantages of CT as the golden standard method for bone diseases' diagnostic with DR's clinical feasibility under field conditions, synchronized CT-DR presents a new perspective on wildlife's health management. With this we hope to provide veterinary

X-ray radiography and tomography applied to material testing

International Nuclear Information System (INIS)

Rechapt, Jean de.

1982-11-01

X-ray radiography and tomography are compared to detect a defect in an object. These image acquisition processes are first modelled by a convolution system. For a fixed contrast defect and a given X ray dose, the process providing the best signal-to-noise ratio is given by calculation. Then a system for pattern recognition is given: for identifying a defect, the related signs from binary images are sorted according to their size. The improvement in the detection performance of the device, for an adapted filtration of the images obtained, is assessed. The whole of the preceding results is validated on images synthesized on a computer, selecting between tomography and radiography, the technique making it possible to ensure the detectability of a defect with a minimal dose of X photons [fr

Application of X-ray radiography to archaeology

International Nuclear Information System (INIS)

Miura, Sadatoshi

1994-01-01

X-ray imaging techniques including radiography and scanning tomography are now often applied to archaeological and historical objects. In this report results of three imaging techniques are showed: radiography, X-ray scanning tomography and emissiography. X-ray radiography was applied to examine the technique used for a bronze object. The object was one of the national treasure from Horyuji-temple, Dragon-head Pitcher. The examination proved that the pitcher body was separated into three pieces and that the bronze was fairly homogeneous from 3 to 4 mm. The Pitcher was supposed to be made in Japan at the middle of the seventh century. A small gilt bronze statuette was investigated by an industrial X-ray scanner. The statuette about 30 cm high is supposed to be made in the seventh or eighth century. The head of the statuette was scanned by X-rays of 350kV. The computed tomograms revealed an inlaid metal and scraped hollow. It is supposed that the statuette was cast twice. The first casting might have failed causing the hollow and the missing part of the head. The hollow was scraped before the following casting so that the newly cast part would be tightly joined to the body. A piece of metal was inlaid to the missing part. A silver inlaid sword was excavated at a historic site called Etafunayama Kofun in Kumamoto in 1873. Seventy-five letters were discovered on the back of the sword, and they were regarded as important reference in studying Japanese history around the fifth century. However, the letters became illegible because of severe surface corrosion. So emissiography or electron radiography was used. All letters and even the details could be read. (author)

Incremental picture archiving and communication system (PACS) - an appraisal

International Nuclear Information System (INIS)

Nagle, K.

2000-01-01

Digital storage phosphor radiography is slowly being introduced in Australia with more sites making the conversion from film/screen to computed radiography or a fully integrated Picture Archiving and Communication System (PACS). St Vincent's Hospital, Melbourne (SVHM) introduced partial PACS for general radiography in June 1996. This involved networking two Fuji CR Image Plate Readers and an existing Kodak KESPR400 Reader with viewing stations strategically placed in Medical Imaging, Casualty and the Intensive and Coronary Care units. No long-term storage device or archive facility was purchased. This installation coincided with the relocation of the Medical Imaging Department (MID) to a fully equipped new site as well as the introduction of the Kestral Radiology Management System. The transition has involved significant changes to the department's design, workflow and the radiographers' work practices. Copyright (1999) Australian Institute of Radiography

An experimental comparative study of radiography, ultrasonography and CT imaging in the IV catheter fragment

International Nuclear Information System (INIS)

Kweon, Dae Cheol

2016-01-01

The objective of this study was to detect the fragments generated during IV (intravenous) catheter injection of contrast medium and drug administration in a clinical setting and removal was performed by experimentally producing a phantom, and to compare the radiography, ultrasonography, and multi-detector computed tomography (MDCT) imaging and radiation dose. A 1 cm fragment of an 18 gage Teflon® IV catheter with saline was inserted into the IV control line. Radiography, CT, and ultrasonography were performed and radiography and CT dose were calculated. CT and ultrasonography showed an IV catheter fragment clinically and radiography showed no visible difference in the ability to provide a useful image of an IV catheter fragment modality (p >.05). Radiography of effective dose (0.2139 mSv·Gy-1·cm-2) form DAP DAP (0.93 μGy·m2 ), and dose length product (DLP) (201 mGy·cm) to effective dose was calculated as 0.483 mSv. IV catheter fragment were detected of radiography, ultrasonography and CT. These results can be obtained by menas of an excellent IV catheter fragment of detection capability CT. However, CT is followed by radiation exposure. IV catheter fragment confirming the position and information recommend an ultrasonography

Neutron-induced alpha radiography

International Nuclear Information System (INIS)

Pereira, Marco Antonio Stanojev

2008-01-01

A new radiography technique to inspect thin samples was developed. Low energy alpha particles, generated by a boron based screen under thermal neutron irradiation, are used as penetrating radiation. The solid state nuclear track detector CR-39 has been used to register the image. The interaction of the α - particles with the CR-39 gives rise to damages which under an adequate chemical etching became tracks the basic units forming the image. A digital system was developed for data acquisition and data analysis as well as for image processing. The irradiation and etching conditions to obtain the best radiography are 1,3 hours and 25 minutes at 70 deg C respectively. For such conditions samples having 10 μm in thickness can be inspected with a spatial resolution of 32 μm. The use of the digital system has reduced the time spent for data acquisition and data analysis and has improved the radiography image visualization. Furthermore, by using the digital system, it was possible to study several new parameters regarding the tracks which are very important to understand and study the image formation theory in solid state nuclear track detectors, the one used in this thesis. Some radiography images are also shown which demonstrate the potential of the proposed radiography technique. When compared with the other radiography techniques already in use to inspect thin samples, the present one developed in the present paper allows a smaller time to obtain the image, it is not necessary to handle liquid radioactive substances, the detector is insensitive to β, γ, X-ray and visible light. (author)

Study of check image using computed radiography

International Nuclear Information System (INIS)

Sato, Hiroshi

2002-01-01

There are two image forming methods both a check image and a portal image in the linacogram. It has been established the image forming method in the check image using computed radiography (CR). On the other hand, it is not established the image forming method in the portal image using CR yet. Usually, in the electric portal imaging device (EPID) is mainly used just before radiotherapy start. The usefulness of the portal image forming method by CR using in place of EPID is possible to confirm the precision for determining to specific position at the irradiate part and to the irradiate method for the human organs. There are some technical problems that, since in the early time, the linac graphy (LG) image have low resolution power. In order to improve to the resolution power in LG image, CR image technologies have been introduced to the check image forming method. Heavy metallic sheet (HMS) is used to the front side of CR-IP cassette, and high contactness sponge is used to the back side of the cassette. Improved contactness between HMS and imaging plate (IP) by means of the high contactness sponge contributed to improve the resolution power in the check images. A lot of paper which is connected with these information have been reported. Imaging plate ST-III should be used to maintain high sensitivity in the check film image forming method. The same image forming method in the check image established by CR has been introduced into the portal image forming method in order to improve the resolution power. However, as a result, it couldn't acquired high resolution image forming in the portal images because of the combination of ST-III and radiotherapy dose. After several trials, it has been recognized that HR-V imaging plate for mammography is the most useful application to maintain high resolution power in the portal images. Also, it is possible to modify the image quality by changing GS parameter which is one of image processing parameters in CR. Furthermore, in case

White light-emitting diodes (LEDs) using (oxy)nitride phosphors

International Nuclear Information System (INIS)

Xie, R-J; Hirosaki, N; Sakuma, K; Kimura, N

2008-01-01

(Oxy)nitride phosphors have attracted great attention recently because they are promising luminescent materials for phosphor-converted white light-emitting diodes (LEDs). This paper reports the luminescent properties of (oxy)nitride phosphors in the system of M-Si-Al-O-N (M = Li, Ca or Sr), and optical properties of white LEDs using a GaN-based blue LED and (oxy)nitride phosphors. The phosphors show high conversion efficiency of blue light, suitable emission colours and small thermal quenching. The bichromatic white LEDs exhibit high luminous efficacy (∼55 lm W -1 ) and the multi-phosphor converted white LEDs show high colour rendering index (Ra 82-95). The results indicate that (oxy)nitride phosphors demonstrate their superior suitability to use as down-conversion luminescent materials in white LEDs

Neutron radiography of Apollo ordnance

International Nuclear Information System (INIS)

Golliher, K.G.

1983-01-01

Neutron radiography played an important role in the successful Apollo missions. Neutron radiography was used, for the first time, on a production basis to examine the internal details of ordnance devices employed in the Apollo Program. Ordnance devices ranged from charges which separated the massive booster stages to those which triggered the release of re-entry parachutes. Discussed are the early developments in neutron radiography and the conversion of this infant nondestructive technology into production capabilities. (Auth.)

Proton radiography using highpower femtosecond laser

International Nuclear Information System (INIS)

Choi, Chang Il

2010-08-01

A femtosecond laser emits pulses whose width is between few and few hundreds femtoseconds (10 -15 s). The production mechanism of the high energy protons generated by the femtosecond laser is not clear so far, but the technologies have been improving. The applications using the generated protons are the proton therapy, proton radiography, nuclear physics, security inspection, and so on. Especially in the radiography, the laser-generated protons are very useful to obtain high quality images of thin objects, because protons are able to penetrate an object following an almost straight path and give a depth distribution information of various elements in a subject. Since the laser-driven protons require lower cost and smaller facility than accelerator-based protons, the radiography using laser-driven protons have been of interest. In this research, we have performed the radiography experiments by using protons generated by the 100 TW titanium sapphire femtosecond laser facility of Advanced Photonics Research Institute (APRI) of Gwangju Institute of Science Technology (GIST). A CR-39 Solid State Nuclear Track Detector (SSNTD) has been used as radiography screen. The radiography digital images have been obtained by using an optical microscope and a CCD camera. Modulation Transfer Function (MTF) has been derived from analyzing the obtained images, and the spatial resolution of the images have been evaluated. And, we have performed the radiography experiments of monoenergetic proton from the Tandem Van de Graaff accelerator of Korea Institute of Geoscience and Mineral Resources (KIGAM). We have obtained and compared the radiography images from other proton production methods which are the laser and the accelerator, respectively. And also, we have found out the optimized chemical etching condition, in order to improve the spatial resolution of the radiography images. Finally, the evaluated maximum spatial resolution of the images are 2.09 μm

Image Acquisition and Quality in Digital Radiography.

Science.gov (United States)

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.

[Change traits of phosphorous consumption structure in China and their effects on environmental phosphorous loads].

Science.gov (United States)

Ma, Dun-Chao; Hu, Shan-Ying; Chen, Ding-Jiang; Li, You-Run

2012-04-01

Substance flow analysis was used to construct a model to analyze change traits of China's phosphorous (P) consumption structure from 1980 to 2008 and their influences on environmental phosphorous loads, then the correlation between several socioeconomic factors and phosphorous consumption pollution was investigated. It is found that phosphorous nutrient inputs of urban life and rural life on a per capita level climbed to 1.20 kg x a(-1) and 0.99 kg x a(-1) from 0.83 kg x a(-1) and 0.75 kg x a(-1) respectively, but phosphorous recycling ratios of urban life fell to 15.6% from 62.6%. P inputs of animal husbandry and planting also kept increasing, but the recycling ratio of the former decreased from 67.5% to 40.5%, meanwhile much P input of the latter was left in agricultural soil. Correlation coefficients were all above 0.90, indicating that population, urbanization level, development levels of planting and animal husbandry were important incentives for P consumption pollution in China. Environmental Kuznets curve showed that China still stayed in the early development stage, promoting economic growth at an expense of environmental quality. This study demonstrates that China's P consumption system is being transformed into a linear and open structure, and that P nutrient loss and environmental P loads increase continually.

Charter of good practices in industrial radiography; Charte de bonnes pratiques en radiographie industrielle

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-07-01

This document describes good practices in the field of industrial radiography. After having presented the main prevention and radiation protection principles, the actors inside and outside of the company, and actors intervening during an operation subcontracting in industrial radiography, this report analyzes the activity: prerequisites for work preparation, prevention coordination, work preparation, transportation, work achievement, return on experience. It addresses personnel training and information, and the dosimetric and medical monitoring of technicians in industrial radiography. Some aspects are addressed in appendix: principles (justification, optimization, and limitation), regulations, intervention form, exposure form, and so on

Inspection reliability comparison of digital radiography, film radiography and radioscopy for inspection of Inconel welds

International Nuclear Information System (INIS)

Meade, W.; Kidwell, C.; Warren, G.

2004-01-01

Digital Radiography offers the promise of economic and environmental advantages over traditional film based inspection. Boeing Commercial Aircraft Group has an on-going effort to evaluate this emerging radiographic method for production of aerospace hardware. Included in this effort was a program to evaluate the potential for utilizing amorphous silicon based digital radiography for the inspection of inconel weldments in engine ducting. For this particular program, probability of detection (POD) studies were conducted to compare the reliability of digital radiography with the existing production processes that utilize film radiography and image-intensifier based radioscopy. Cycle time studies were also conducted to determine the potential economic benefit for switching to the new process. The methodology and findings of this comparison are presented. (author)

Inspection reliability comparison of digital radiography, film radiography and radioscopy for inspection of Inconel welds

Energy Technology Data Exchange (ETDEWEB)

Meade, W.; Kidwell, C.; Warren, G. [Boeing Commercial Aircraft Group, Renton, Washington (United States)

2004-07-01

Digital Radiography offers the promise of economic and environmental advantages over traditional film based inspection. Boeing Commercial Aircraft Group has an on-going effort to evaluate this emerging radiographic method for production of aerospace hardware. Included in this effort was a program to evaluate the potential for utilizing amorphous silicon based digital radiography for the inspection of inconel weldments in engine ducting. For this particular program, probability of detection (POD) studies were conducted to compare the reliability of digital radiography with the existing production processes that utilize film radiography and image-intensifier based radioscopy. Cycle time studies were also conducted to determine the potential economic benefit for switching to the new process. The methodology and findings of this comparison are presented. (author)

Diagnostic ability of panoramic radiography for mandibular fractures

International Nuclear Information System (INIS)

Lee, Ji Hyun; Jung, Yun Hoa; Cho Bong Hae; Hwang, Dae Seok

2010-01-01

The purpose of this study was to evaluate the diagnostic efficacy of panoramic radiographs for detection of mandibular fractures. The sample was comprised of 65 patients (55 fractured, 10 non-fractured) with 92 fracture sites confirmed by multi-detector computed tomography (CT). Panoramic radiographs were evaluated for mandibular fractures by six examiners; two oral and maxillofacial radiologists (observer A and B), two oral and maxillofacial surgeons (observer C and D), and two general dentists (observer E and F). Sensitivity of panoramic radiography for mandibular fractures was 95.7% in observer A and B, 93.5% in observer C and D and 80.4% in observer E and F. The lowest sensitivity was shown in symphyseal/parasymphyseal areas, followed by subcondylar/condylar regions. Panoramic radiography is adequate for detection of mandibular fractures. However, additional multidetector CT is recommended to ascertain some indecisive fractures of symphysis and condyle, and in complicated fractures.

Diagnostic ability of panoramic radiography for mandibular fractures

Energy Technology Data Exchange (ETDEWEB)

Lee, Ji Hyun; Jung, Yun Hoa; Cho Bong Hae; Hwang, Dae Seok [School of Dentistry, Pusan National University, Pusan (Korea, Republic of)

2010-03-15

The purpose of this study was to evaluate the diagnostic efficacy of panoramic radiographs for detection of mandibular fractures. The sample was comprised of 65 patients (55 fractured, 10 non-fractured) with 92 fracture sites confirmed by multi-detector computed tomography (CT). Panoramic radiographs were evaluated for mandibular fractures by six examiners; two oral and maxillofacial radiologists (observer A and B), two oral and maxillofacial surgeons (observer C and D), and two general dentists (observer E and F). Sensitivity of panoramic radiography for mandibular fractures was 95.7% in observer A and B, 93.5% in observer C and D and 80.4% in observer E and F. The lowest sensitivity was shown in symphyseal/parasymphyseal areas, followed by subcondylar/condylar regions. Panoramic radiography is adequate for detection of mandibular fractures. However, additional multidetector CT is recommended to ascertain some indecisive fractures of symphysis and condyle, and in complicated fractures.

Re-processing CRT phosphors for mercury-free applications

International Nuclear Information System (INIS)

Dexpert-Ghys, Jeannette; Regnier, Sophie; Canac, Sophie; Beaudette, Tristan; Guillot, Philippe; Caillier, Bruno; Mauricot, Robert; Navarro, Julien; Sekhri, Salem

2009-01-01

This study is part of an operation in the framework of treatment and revalorization of IEEE (Informatics, Electronics and related) wastes. It aims to recover the active phosphors in cathode ray tubes (CRTs) and to re-cycle these powders by appropriate treatments as phosphors for mercury-free applications such as plasma display panels, flat lamps, advertising and lighting. The studied waste comes from a large panel of CRTs from any supplier. Several thermo-chemical treatments have been investigated. The removal of zinc sulfide-based phosphors and the recovery of a red phosphor Y 2 O 3 :Eu 3+ has been achieved by one (basic attack) route. The photoluminescence efficiency under VUV excitation of the obtained powders is at most 30% that of a commercial phosphor. The second route (acid attack) appears less promising. It has been established that silicate-based impurities could prevent isolating the yttrium based phosphor.

Re-processing CRT phosphors for mercury-free applications

Energy Technology Data Exchange (ETDEWEB)

Dexpert-Ghys, Jeannette, E-mail: jdexpert@cemes.f [CEMES, 29 rue Jeanne Marvig, BP 94347, 31055 Toulouse cedex 4 (France); Regnier, Sophie; Canac, Sophie [ICAM, 75 avenue de Grande Bretagne, 31300 Toulouse (France); Beaudette, Tristan; Guillot, Philippe; Caillier, Bruno [DPHE, Universite Jean Francois Champollion, place de Verdun, 81012 Albi cedex 9 (France); Mauricot, Robert; Navarro, Julien [CEMES, 29 rue Jeanne Marvig, BP 94347, 31055 Toulouse cedex 4 (France); Sekhri, Salem [ENVOI, Cheminement Glueck, 31100 Toulouse (France)

2009-12-15

This study is part of an operation in the framework of treatment and revalorization of IEEE (Informatics, Electronics and related) wastes. It aims to recover the active phosphors in cathode ray tubes (CRTs) and to re-cycle these powders by appropriate treatments as phosphors for mercury-free applications such as plasma display panels, flat lamps, advertising and lighting. The studied waste comes from a large panel of CRTs from any supplier. Several thermo-chemical treatments have been investigated. The removal of zinc sulfide-based phosphors and the recovery of a red phosphor Y{sub 2}O{sub 3}:Eu{sup 3+} has been achieved by one (basic attack) route. The photoluminescence efficiency under VUV excitation of the obtained powders is at most 30% that of a commercial phosphor. The second route (acid attack) appears less promising. It has been established that silicate-based impurities could prevent isolating the yttrium based phosphor.

Uranium recovery from wet-process phosphoric acid

International Nuclear Information System (INIS)

McCullough, J.F.; Phillips, J.F. Jr.; Tate, L.R.

1979-01-01

A method of recovering uranium from wet-process phosphoric acid is claimed where the acid is treated with a mixture of an ammonium salt or ammonia, a reducing agent, and then a miscible solvent. Solids are separated from the phosphoric acid liquid phase. The solid consists of a mixture of metal phosphates and uranium. It is washed free of adhering phosphoric acid with fresh miscible solvent. The solid is dried and dissolved in acid whereupon uranium is recovered from the solution. Miscible solvent and water are distilled away from the phosphoric acid. The distillate is rectified and water discarded. All miscible solvent is recovered for recycle. 5 claims

A Versatile Image Processor For Digital Diagnostic Imaging And Its Application In Computed Radiography

Science.gov (United States)

Blume, H.; Alexandru, R.; Applegate, R.; Giordano, T.; Kamiya, K.; Kresina, R.

1986-06-01

In a digital diagnostic imaging department, the majority of operations for handling and processing of images can be grouped into a small set of basic operations, such as image data buffering and storage, image processing and analysis, image display, image data transmission and image data compression. These operations occur in almost all nodes of the diagnostic imaging communications network of the department. An image processor architecture was developed in which each of these functions has been mapped into hardware and software modules. The modular approach has advantages in terms of economics, service, expandability and upgradeability. The architectural design is based on the principles of hierarchical functionality, distributed and parallel processing and aims at real time response. Parallel processing and real time response is facilitated in part by a dual bus system: a VME control bus and a high speed image data bus, consisting of 8 independent parallel 16-bit busses, capable of handling combined up to 144 MBytes/sec. The presented image processor is versatile enough to meet the video rate processing needs of digital subtraction angiography, the large pixel matrix processing requirements of static projection radiography, or the broad range of manipulation and display needs of a multi-modality diagnostic work station. Several hardware modules are described in detail. For illustrating the capabilities of the image processor, processed 2000 x 2000 pixel computed radiographs are shown and estimated computation times for executing the processing opera-tions are presented.

Comparison of the efficacy of conventional radiography, digital radiography, and ultrasound in diagnosing periapical lesions.

Science.gov (United States)

Raghav, Namita; Reddy, Sujatha S; Giridhar, A G; Murthy, Srinivas; Yashodha Devi, B K; Santana, N; Rakesh, N; Kaushik, Atul

2010-09-01

The aim of this study was to evaluate the efficacy of conventional radiography, digital radiography and ultrasound imaging in diagnosing periapical lesions. Twenty-one patients aged between 15 and 45 years with well defined periapical radiolucency associated with anterior maxillary or mandibular teeth requiring endodontic surgery or extraction were selected and consented to the study. Preoperative intraoral periapical radiographs and digital images using charge-coupled device obtained by paralleling technique were assessed by 3 specialist observers who gave their diagnosis of the periapical lesions. Then ultrasound examination was performed and the images were assessed for size, contents, and vascular supply by 3 ultrasonographers. It was followed by curettage of periapical tissues to enable histopathologic investigation, which is the gold standard in diagnosis. The data were statistically analyzed using SPSS, analysis of variance, and kappa statistics. The percentage accuracy of diagnosing periapical lesions using conventional radiography was 47.6%, digital radiography 55.6%, and ultrasound 95.2%. Ultrasound had the highest sensitivity and specificity: 0.95 and 1.00, respectively. Conventional and digital radiography enable diagnosis of periapical diseases, but not their nature, whereas ultrasound provides accurate information on the pathologic nature of the lesions, which is of importance in predicting the treatment outcome. Therefore ultrasound can be used as an adjunct to conventional or digital radiography in diagnosing periapical lesions. Copyright (c) 2010 Mosby, Inc. All rights reserved.

Phosphorous-Containing Polymers for Regenerative Medicine

Science.gov (United States)

Watson, Brendan M.; Kasper, F. Kurtis; Mikos, Antonios G.

2014-01-01

Disease and injury have resulted in a large, unmet need for functional tissue replacements. Polymeric scaffolds can be used to deliver cells and bioactive signals to address this need for regenerating damaged tissue. Phosphorous-containing polymers have been implemented to improve and accelerate the formation of native tissue both by mimicking the native role of phosphorous groups in the body and by attachment of other bioactive molecules. This manuscript reviews the synthesis, properties, and performance of phosphorous-containing polymers that can be useful in regenerative medicine applications. PMID:24565855

Preparation of high purification and food grade phosphoric acid from technical grade phosphoric acid by liquid-liquid detraction method

International Nuclear Information System (INIS)

Alimoradi, M.; Borji, F.; Kishani, A.

2002-01-01

Pay attention to increasing consumption of high purification and food grade phosphoric acid in various industries and food industries and on in on hand and lack of preparation between production and distribution of this products its purification is so vital. In this article of liquid-liquid extraction method with normal hexane-mixture of ammonia and acetone-diisopropyl alcohol and normal butanol solvents and these determination of distribution coefficient each one with ph-me try titration we can evaluate effectiveness and sufficiency each one. Because of proper coefficient distribution and its local production of normal butanol solvent and low price is the best solvent. To phosphoric acid modifying coefficient distribution for extraction of phosphoric acid we can add a little value sulfuric acid to the mixture and to remove flouride impurity we add a little Na 2 O. After extraction stage extracted phosphoric acid in the normal strips by evaluating with distilled water and then by passing the carbon active bed and following passes of cationic resine column and concentrated with vacuum distillation. Conclusion of this article is produce of phosphoric acid 85% w/w and food grade from impure phosphoric acid 52% w/w with technical grade

Neutron radiography by using JSW baby cyclotron

International Nuclear Information System (INIS)

Toda, Yojiro

1995-01-01

At present, JSW baby cyclotrons are mostly used for the production of the radioisotopes for medical use. The attempt to use this baby cyclotron for neutron radiography began already in 1981. The feasibility of the neutron radiography for the explosives in metallic cases which are used for H1 rockets was investigated. In 1983, it was shown that the neutron radiography by using the baby cyclotron in Muroran Works, Japan Steel Works, Ltd. was able to be carried out as a routine work. Since then, the nondestructive inspection by neutron radiography has been performed for rocket pyrotechnic articles, and contributed to heighten their reliability. Further, the radiography by using fast neutrons was developed and put to practical use for recent large H2 rockets. The JSW baby cyclotron BC 168 which has been used for neutron radiography can accelerate 16 MeV protons or 8 MeV deuterons up to 50 μA. The principle of thermal neutron radiography is the generation of fast neutrons by irradiating a Be target with the proton beam accelerated by a baby cyclotron, the moderation of the fast neutrons, the formation of the thermal neutron flux of uniform distribution with a collimator, the thermal neutron flux hitting the Gd plate in a film cassette through an object, and the exposure of an X-ray film to electrons from the Gd plate. Fast neutron radiography apparatus, and commercial neutron radiography are described. (K.I.)

Pretreatment of phosphoric acid of Annaba

International Nuclear Information System (INIS)

Kada, R.

1990-03-01

The most important step in the process of uranium recovery from phosphoric acid is the pretreatment operation. In this study, the adsorption of organic matters on activated carbon was carried out in a batch process and in a fixed bed column. First, the chemical and physical characterization of phosphoric acid, activated carbon and gypsum were performed. In addition, the organic matters were qualitatively analysed and a new and original quantitative method was experimented. Next, the various operating parameters such as agitation speed, granulometry, temperature, solid/liquid ratio, initial concentration, acid flowrate, and bed height were optimized. The experimental equilibrium isotherm was compared to the Langmuir, Freundlich, and Redlich-Peterson theoretical isotherms. It was noticed that the three models did not fit the experimental isotherm in the total concentration range. Thus, an original bilinear model was proposed. The influence of the operating conditions on the adsorption kinetics was also investigated. As a result of that, a new mathematical model was proposed to determine both the liquid and solid phases mass transfer and the solid phase diffusion coefficient. Finally, adsorption of organic matters on a fixed bed process allowed computation of the number of transfer units (NTU), the height of adsorption zone and the degree of saturation of activated carbon

New medical application: nuclear scattering radiography

International Nuclear Information System (INIS)

Saudinos, J.

1977-01-01

Nuclear scattering of 1 GeV protons is used to obtain three dimensional radiographies with a volume resolution of about 1 mm 3 . The information is different from the one given by X-ray radiographies and in particular one may get radiographies of the hydrogen included in objects. Results on a vertebral column and a 'sella turcica' are presented [fr

Comparison of computerized digital and film-screen radiography: response to variation in imaging kVp

Energy Technology Data Exchange (ETDEWEB)

Broderick, N J; Long, B; Dreesen, R G; Cohen, M D; Cory, D A [Riley Hospital for Children, Indiana Univ. School of Medicine, Indianapolis, IN (United States). Dept. of Radiology; Katz, B P; Kalasinski, L A [Regenstreif Inst., Indiana Univ. School of Medicine, Indianapolis, IN (United States). Dept. of Medicine

1992-09-01

A controlled prospective study, in an animal model chosen to simulate portable neonatal radiography, was performed to compare the response of the Philips Computed Radiography (CR) system and conventional 200 speed film-screen (FS) to variation in imaging kVp. Acceptable images were obtained on the CR system over a very wide kVp range. In contrast the FS system produced acceptable images over a narrow kVp range. This ability suggests that the CR system should eliminate the need for repeat examinations in cases where a suboptimal kVp setting would have resulted in an unacceptable FS image. CR technology should therefore be ideally suited to portable radiography especially in situations where selection of correct exposure factors is difficult as in the neonatal nursery. (orig.).

Comparison of computerized digital and film-screen radiography: response to variation in imaging kVp

International Nuclear Information System (INIS)

Broderick, N.J.; Long, B.; Dreesen, R.G.; Cohen, M.D.; Cory, D.A.; Katz, B.P.; Kalasinski, L.A.

1992-01-01

A controlled prospective study, in an animal model chosen to simulate portable neonatal radiography, was performed to compare the response of the Philips Computed Radiography (CR) system and conventional 200 speed film-screen (FS) to variation in imaging kVp. Acceptable images were obtained on the CR system over a very wide kVp range. In contrast the FS system produced acceptable images over a narrow kVp range. This ability suggests that the CR system should eliminate the need for repeat examinations in cases where a suboptimal kVp setting would have resulted in an unacceptable FS image. CR technology should therefore be ideally suited to portable radiography especially in situations where selection of correct exposure factors is difficult as in the neonatal nursery. (orig.)

Radiation Safety in Industrial Radiography. Specific Safety Guide

International Nuclear Information System (INIS)

2011-01-01

This Safety Guide provides recommendations for ensuring radiation safety in industrial radiography used in non-destructive testing. This includes industrial radiography work that utilizes X ray and gamma sources, both in shielded facilities that have effective engineering controls and in outside shielded facilities using mobile sources. Contents: 1. Introduction; 2. Duties and responsibilities; 3. Safety assessment; 4. Radiation protection programme; 5. Training and qualification; 6. Individual monitoring of workers; 7. Workplace monitoring; 8. Control of radioactive sources; 9. Safety of industrial radiography sources and exposure devices; 10. Radiography in shielded enclosures; 11. Site radiography; 12. Transport of radioactive sources; 13. Emergency preparedness and response; Appendix: IAEA categorization of radioactive sources; Annex I: Example safety assessment; Annex II: Overview of industrial radiography sources and equipment; Annex III: Examples of accidents in industrial radiography.

Acceptance testing and commissioning of Kodak Directview CR-850 digital radiography system.

Science.gov (United States)

Bezak, E; Nelligan, R A

2006-03-01

This Technical Paper describes Acceptance Testing and Commissioning of the Kodak DirectView CR-850 digital radiography system installed at the Royal Adelaide Hospital. The first of its type installed in Australia, the system is a "dry" image processor, for which no chemicals are required to develop images. Rather, latent radiographic images are stored on photostimulable phosphor screens, which are scanned and displayed by a reader unit. The image can be digitally processed and enhanced before it is forwarded to a storage device, printer or workstation display, thereby alleviating the need to re-expose patients to achieve satisfactory quality images. The phosphor screens are automatically erased, ready for re-use. Results are reported of tests carried out using the optional "Total Quality Tool" quality assurance package installed with the system. This package includes analysis and reporting software which provides for simple testing and reporting of many important characteristics of the system, such as field uniformity, aspect ratio, line and pixel positions, image and system noise, exposure response, scan linearity, modulation transfer function (MTF) and image artefacts. Acceptance Tests were performed for kV and MV exposures. Resolution for MV exposures was at least 0.8 l/mm, and measured phantom dimensions were within 1.05% of expected magnification. Reproducibility between cassettes was within 1.6%. The mean pixel values on the central axis were close to linear for MV exposures from 3 to 10 MU and reached saturation level at around 20 MU for 6 MV and around 30 MV for 23 MV beams. Noise levels were below 0.2 %.

Workshop on industrial isotope radiography: Programme and lectures

International Nuclear Information System (INIS)

1979-01-01

The booklet contains the texts of lectures delivered in the Workshop on Industrial Radiography held at Bombay during 24-25 July 1979. The lectures cover some topics of relevance to industrial radiography. The topics are radiation protection and legislative aspects in industrial radiography; problems in field radiography in fertilizer industry, petrochemical industry and heavy engineering industry; occupational exposures in industrial radiography; and a review of the progress and recent trends in industrial radiographic techniques and equipment. (M.G.B.)

Pretreatment of industrial phosphoric acid by Algerian filter-aids

International Nuclear Information System (INIS)

Mellah, A.; Setti, Louisa; Chegrouche, Salah

1993-01-01

The present work involves the filtration of industrial phosphoric acid by different filter-aids such as kieselguhr, celite and bleaching clay. The retention of substances contained in wet phosphoric acid was determined using the three filter-aids. Thus, the phosphoric acid, obtained by filtration on kieselguhr has the same specifications as technical phosphoric acid produced by Rhone-Poulenc (France) as standard

Digital Radiography in Kenya today

International Nuclear Information System (INIS)

Omenta, E.N.

2006-01-01

Its nearly one year and a half since digital imaging/radiography was introduced in Kenya mainly in Nairobi. the technology is becoming an increasingly effective and acceptable modality of producing radiographs from the traditional conventional radiography in use to date. the digital radiography offers numerous advantages that have been noted for the short period over the conventional way. For instance radiographs are produced in real time (less than 3 minutes), by so doing the technology has eliminated the wait for the processing period. the radiation exposure to the patient under the radiological examination is reduced as much as 90% from the traditional conventional film taking. The cost, labour and record-keeping necessary to maintain a chemical processor and darkroom operations are as well eliminated. The cost of purchasing and disposing of film wastes/darkroom processing chemicals, which are environmentally hazardous, also become unnecessary.digital radiography technology makes the digital images comparable to other images on the screen at that instant making both the patient and the clinician easily access images when needed. digital receptors have also replaced the cassette containing intensifying screens and film that is used in conventional radiography

Diagnostic radiography: A study in distancing

International Nuclear Information System (INIS)

Reeves, Pauline J.; Decker, Sola

2012-01-01

Aims: This article aims to explore the ways in which diagnostic radiographers use distancing as a tool for emotional management in radiography practice. Methods: This review utilises data from oral history interviews undertaken as part of a larger study documenting the oral history of the diagnostic radiography profession in the United Kingdom as recounted by 24 participants. Results: The results are presented as illustrative of various aspects of the role of the diagnostic radiographer including the initial choice of diagnostic radiography as a profession, the endemic use of particular terminology, the nature of the encounter in diagnostic radiography (including that of sectional imaging) and whether the role is really patient-centred. Conclusions: The article concludes by suggesting that distancing from the patient is mediated by the need for physical touch in order to position the patient for radiography and also makes the suggestion that those opting for diagnostic radiography as a career may do so because they want a profession which is more distanced from the patient and that, even where this is not the case initially, individuals are socialised into adopting the ‘feeling rules’ of the profession. The article concludes by outlining potential areas for further research.

Uranium extraction from phosphoric acid

International Nuclear Information System (INIS)

Araujo Figueiredo, C. de

1984-01-01

The recovery of uranium from phosphoric liquor by two extraction process is studied. First, uranium is reduced to tetravalent condition and is extracted by dioctypyrophosphoric acid. The re-extraction is made by concentrated phosphoric acid with an oxidizing agent. The re-extract is submitted to the second process and uranium is extracted by di-ethylhexilphosphoric acid and trioctylphosphine oxide. (M.A.C.) [pt

Phosphate Phosphors for Solid-State Lighting

CERN Document Server

Shinde, Kartik N; Swart, H C; Park, Kyeongsoon

2012-01-01

The idea for this book arose out of the realization that, although excellent surveys and a phosphor handbook are available, there is no single source covering the area of phosphate based phosphors especially for lamp industry. Moreover, as this field gets only limited attention in most general books on luminescence, there is a clear need for a book in which attention is specifically directed toward this rapidly growing field of solid state lighting and its many applications. This book is aimed at providing a sound introduction to the synthesis and optical characterization of phosphate phosphor for undergraduate and graduate students as well as teachers and researchers. The book provides guidance through the multidisciplinary field of solid state lighting specially phosphate phosphors for beginners, scientists and engineers from universities, research organizations, and especially industry. In order to make it useful for a wide audience, both fundamentals and applications are discussed, together.

Industrial Radiography Safety in Australia

International Nuclear Information System (INIS)

Hockings, Colin

2006-01-01

The first applications of the imaging capability of X-rays were non-medical. Roentgen produced images of his shotgun, a compass and a set of weights in a closed box to show his colleagues. Prior to 1912, X-rays were used little outside the realms of medicine and dentistry because the X-ray tubes failed under the higher voltages required for industrial purposes. However, that changed in 1913 when high vacuum X-ray tubes designed by Coolidge became available. In 1922, industrial radiography took another step forward with the advent of the 200,000-volt X-ray tube that allowed radiographs of thick steel parts to be produced in a reasonable amount of time. In 1931 the American Society of Mechanical Engineers (ASME) permitted approval of fusion welded pressure vessels by x-ray, which promoted an acceptance and use of the method. That application continues. Radium became the initial gamma ray source for industrial radiography. The material allowed radiography of castings up to 30cm thick. During World War II, industrial radiography grew significantly as part of the US Navy's shipbuilding-program, and in 1946 gamma ray sources such as cobalt 60 and iridium 192 became available. These new sources gained rapid popularity because they emitted more intense radiation than radium and were less expensive. Present state: the majority of industrial radiography techniques have changed little since their inception. An image is captured, processed and analysed for evidence of fault or defect. Today however, the images are of higher quality and greater sensitivity, through the use of better quality films, smaller radiation sources and automated processing. Developments in electronics and computers now allow technicians to create a digital image, enhance it, transmit it or store it indefinitely. The most noticeable change in industrial radiography equipment from the technician's view would be the reduction in weight of the equipment for a given kV output. Never the less it remains

X-ray investigation of phosphors for black-white television

International Nuclear Information System (INIS)

Lazowy, B.

1975-01-01

The investigations of phosphors made by means of the powder diffraction method are presented. The diffraction patterns has been obtained by means of the DRON-1 diffractometer, using the Ksub(α) copper radiation and a nickel filter. Reflex intensity was estimated, indexing was made and lattice constants for particular structure types were calculated. The objects of the investigations were the phosphors from various firms of white luminescence and home phosphors of white, blue and yellow luminescence. On the base of the results it was found that all investigated phosphors of yellow luminescence belonged to the hexagonal system. These phosphors, depending on baking conditions, have structure of regular symmetry. The phosphors of white luminescence are a mixture of hexagonal and regular phase and any changes in elementary cell sizes were not observed. All phosphors of white luminescence have analogous structure, positions of all reflexes are identical, negligible differences in their intensities occur only, which proves somewhat different arrangement of atoms in mixed crystals. (author)

Functioning of industrial radiography services

International Nuclear Information System (INIS)

Alves, R.N.; Costa, H.M. da; Bianchini, F.G.; Arrieta, L.A.I.

1988-12-01

The objective of this norm is establish the necessary requirements for the functioning of industrial radiography services, as well as the procedures for acquisition and transfer of radioactive sources and/or X-ray equipments used in industrial radiography [pt

Visibility of Different Intraorbital Foreign Bodies Using Plain Radiography, Computed Tomography, Magnetic Resonance Imaging, and Cone-Beam Computed Tomography: An In Vitro Study.

Science.gov (United States)

Javadrashid, Reza; Golamian, Masoud; Shahrzad, Maryam; Hajalioghli, Parisa; Shahmorady, Zahra; Fouladi, Daniel F; Sadrarhami, Shohreh; Akhoundzadeh, Leila

2017-05-01

The study sought to compare the usefulness of 4 imaging modalities in visualizing various intraorbital foreign bodies (IOFBs) in different sizes. Six different materials including metal, wood, plastic, stone, glass. and graphite were cut in cylindrical shapes in 4 sizes (dimensions: 0.5, 1, 2, and 3 mm) and placed intraorbitally in the extraocular space of fresh sheep's head. Four skilled radiologists rated the visibility of the objects individually using plain radiography, spiral computed tomography (CT), magnetic resonance imaging (MRI), and cone-beam computed tomography (CBCT) in accordance with a previously described grading system. Excluding wood, all embedded foreign bodies were best visualized in CT and CBCT images with almost equal accuracies. Wood could only be detected using MRI, and then only when fragments were more than 2 mm in size. There were 3 false-positive MRI reports, suggesting air bubbles as wood IOFBs. Because of lower cost and using less radiation in comparison with conventional CT, CBCT can be used as the initial imaging technique in cases with suspected IOFBs. Optimal imaging technique for wood IOFBs is yet to be defined. Copyright © 2016 Canadian Association of Radiologists. Published by Elsevier Inc. All rights reserved.

Pretreatment of phosphoric acid for uranium recovery by the wet phosphoric acid process

International Nuclear Information System (INIS)

Chern, S.L.P.; Chen, Y.C.L.; Chang, S.S.H.; Kuo, T.S.; Ting, G.C.M.

1980-01-01

The proposal deals with reprocessing of phosphoric acid arising from uranium separation according to the wet phosphoric acid process and being intended for recycling. In detail, the sludge will be removed by means of an inclined separating device containing corrugated plates, then the organic impurities are washed out with kerosene in suitable facilities, and the crude phase remaining in the settling tank will be separated from the kerosene in a separating centrifuge. The method has only got low cost of installation. (UWI) [de

Computed tomography in facial trauma

International Nuclear Information System (INIS)

Zilkha, A.

1982-01-01

Computed tomography (CT), plain radiography, and conventional tomography were performed on 30 patients with facial trauma. CT demonstrated bone and soft-tissue involvement. In all cases, CT was superior to tomography in the assessment of facial injury. It is suggested that CT follow plain radiography in the evaluation of facial trauma

Compact fluorescent lamp phosphors in accidental radiation monitoring

International Nuclear Information System (INIS)

Murthy, K. V. R.; Pallavi, S. P.; Ghildiyal, R.; Parmar, M. C.; Patel, Y. S.; Ravi Kumar, V.; Sai Prasad, A. S.; Natarajan, V.; Page, A. G.

2006-01-01

The application of lamp phosphors for accidental dosimetry is a new concept. Since the materials used in fluorescent lamps are good photo luminescent materials, if one can either use the inherent defects present in the phosphor or add suitable modifiers to induce thermoluminescence (TL) in these phosphors, then the device (fluorescent lamp) can be used as an accidental dosemeter. In continuation of our search for a suitable phosphor material, which can serve both as an efficient lamp phosphor and as a good radiation monitoring device, detailed examination has been carried out on cerium and terbium-doped lanthanum phosphate material. A 90 Sr beta source with 50 mCi strength (1.85 GBq) was used as the irradiation source for TL studies. The TL response as a function of dose received was examined for all phosphors used and it was observed that the intensity of the TL peak vs. dose received was a linear function in the dose range 0.1-200 Gy in each case. Incidentally LaPO 4 :Ce,Tb is a component of the compact fluorescent lamp marketed recently as an energy bright light source. Besides having very good luminescence efficiency, good dosimetric properties of these phosphors render them useful for their use in accidental dosimetry also. (authors)

Standard practice for digital imaging and communication nondestructive evaluation (DICONDE) for computed radiography (CR) test methods

CERN Document Server

American Society for Testing and Materials. Philadelphia

2010-01-01

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

Are radiography lecturers, leaders?

International Nuclear Information System (INIS)

Hendry, Julie Anne

2013-01-01

This review article aims to explore the concept of radiography lecturers acting as leaders to their student followers. Through a brief review of the literature, a definition of leadership is suggested and some leadership theories explored. The path-goal theory, leader–member exchange theory and the contemporary theory of transformational leadership are examined more closely. Links between lecturer-leader behaviour and student motivation and learning are tentatively suggested with transformational leadership appearing to offer the optimal leadership style for lecturers to adopt. The paucity of literature relating directly to radiography is acknowledged and areas for further research are suggested. The article concludes with some of the author's practical ideas for incorporating transformational leadership styles and behaviours into radiography education today

Comparative adoption of cone beam computed tomography and panoramic radiography machines across Australia.

Science.gov (United States)

Zhang, A; Critchley, S; Monsour, P A

2016-12-01

The aim of the present study was to assess the current adoption of cone beam computed tomography (CBCT) and panoramic radiography (PR) machines across Australia. Information regarding registered CBCT and PR machines was obtained from radiation regulators across Australia. The number of X-ray machines was correlated with the population size, the number of dentists, and the gross state product (GSP) per capita, to determine the best fitting regression model(s). In 2014, there were 232 CBCT and 1681 PR machines registered in Australia. Based on absolute counts, Queensland had the largest number of CBCT and PR machines whereas the Northern Territory had the smallest number. However, when based on accessibility in terms of the population size and the number of dentists, the Australian Capital Territory had the most CBCT machines and Western Australia had the most PR machines. The number of X-ray machines correlated strongly with both the population size and the number of dentists, but not with the GSP per capita. In 2014, the ratio of PR to CBCT machines was approximately 7:1. Projected increases in either the population size or the number of dentists could positively impact on the adoption of PR and CBCT machines in Australia. © 2016 Australian Dental Association.

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

International Nuclear Information System (INIS)

Dewanckele, J.; De Kock, T.; Fronteau, G.; Derluyn, H.; Vontobel, P.; Dierick, M.; Van Hoorebeke, L.; Jacobs, P.; Cnudde, V.

2014-01-01

Euville and Savonnières limestones were weathered by acid test and this resulted in the formation of a gypsum crust. In order to characterize the crystallization pattern and the evolution of the pore structure below the crust, a combination of high resolution X-ray computed tomography and SEM–EDS was used. A time lapse sequence of the changing pore structure in both stones was obtained and afterwards quantified by using image analysis. The difference in weathering of both stones by the same process could be explained by the underlying microstructure and texture. Because water and moisture play a crucial role in the weathering processes, water uptake in weathered and non-weathered samples was characterized based on neutron radiography. In this way the water uptake was both visualized and quantified in function of the height of the sample and in function of time. In general, the formation of a gypsum crust on limestone slows down the initial water uptake in the materials. - Highlights: • Time lapse sequence in 3D of changing pore structures inside limestone • A combination of X-ray CT, SEM and neutron radiography was used. • Quantification of water content in function of time, height and weathering • Characterization of weathering processes due to gypsum crystallization

Industrial radiography techniques and their applications

International Nuclear Information System (INIS)

Wamorkar, R.R.

1981-01-01

Various aspects of industrial radiography are discussed. These include: radiation sources, geometrical unsharpness of image, radiation attenuation in the specimen, radiation effect of film, types of film, intensifying screens, exposure time calculations, source to film distance and sensivitity. Radiography techniques for examination of welded joints on flat plate and pipes or cylindrical objects, and castings are indicated. Applications of radiography in various industries are mentioned. (M.G.B.)

Vertebral Fracture Assessment in Supine Position : Comparison by Using Conventional Semiquantitative Radiography and Visual Radiography

NARCIS (Netherlands)

Hospers, Ilone C.; van der Laan, Johan G.; Zeebregts, Clark J.; Nieboer, Patrick; Wolffenbuttel, Bruce H. R.; Dierckx, Rudi A.; Kreeftenberg, Herman G.; Jager, Pieter L.; Slart, Riemer H. J. A.

Purpose: To retrospectively evaluate the accuracy of vertebral fracture assessment (VFA) performed with the patient in the supine position and conventional semiquantitative radiography of the spine by using conventional visual radiography of the spine as the reference standard. Materials and

A Neutron Radiography System for Field Use

Science.gov (United States)

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

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

International Nuclear Information System (INIS)

Dom, Sulaiman M.; Yusoff, Nadzri M.; Amin, Zulkifli M.

2010-01-01

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

High efficiency nitride based phosphores for white LEDs

NARCIS (Netherlands)

Li, Yuan Qiang; Hintzen, H.T.J.M.

2008-01-01

In this overview paper, novel rare-earth doped silicon nitride based phosphors for white LEDs applications have been demonstrated. The luminescence properties of orange-red-emitting phosphors (M2Si5N8:Eu2+) and green-to-yellow emitting phosphors (MSi2N2O2:Eu2+, M = Ca, Sr, Ba) are discussed in

Tm3+ activated lanthanum phosphate: a blue PDP phosphor

International Nuclear Information System (INIS)

Rao, R.P.

2005-01-01

Plasma display panels (PDPs) are gaining attention due to their high performance and scalability as a medium for large format TVs. The performance and life of a PDP strongly depends upon the nature of phosphors. Currently, Eu 2+ activated barium magnesium aluminate (BAM) is being used as a blue component. Because of its low life, efforts are being made to explore new blue emitting phosphors. One of the alternatives to BAM is Tm 3+ activated lanthanum phosphate (LPTM) phosphor. LPTM phosphor samples are prepared by a solid-state as well as sol-gel process in presence of flux. The phosphor of the present investigation, having uniform and spherical shape particles in the range of 0.1-2 μm, is appropriate for thin phosphor screens required for PDP applications. It exhibits a narrow band emission in the blue region, peaking at 452 nm and also a number of narrow bands in the UV region when excited by 147 and 173 nm radiation from a xenon gas mixture. Various possible transitions responsible for UV and visible emission from Tm 3+ ion are presented. These phosphors also exhibit good color saturation and better stability when excited with VUV radiation. To achieve higher brightness, they are blended with other UV excited blue emitting phosphors such as BAM. Results related to morphology, excitation, after glow decay, emission and degradation of these phosphors in the powder form as well as in plasma display panels are presented and discussed

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-06-15

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

Method of recovering phosphoric acid type decontaminating electrolytes by electrodeposition

International Nuclear Information System (INIS)

Sasaki, Takashi; Wada, Koichi; Kobayashi, Toshio.

1985-01-01

Purpose: To recoving phosphoric acid type highly concentrated decontaminating liquid used for the electrolytic decontamination of contaminated equipments, components, etc in nuclear power plants or the like through electrodeposition by diaphragm electrolysis. Method: Before supplying phosphoric acid decontaminating liquid at high concentration used in the electrolytic decontaminating step to an electrodeposition recovering tank, phosphoric acid in the decontaminating electrolyte is extracted with solvents and decomposed liquid extracts (electrolyte reduced with the phosphoric acid component) are supplied to the cathode chamber of the electrodeposition recovering tank, where phosphoric acid is back-extracted with water from the solvents after extraction of phosphoric acid. Then, the back-extracted liquids (aqueous phosphoric acid solution scarcely containing metal ions) are sent to the anode chamber of the electrodeposition recovering tank. Metal ions in the liquid are captured by electrodeposition in the cathode chamber, as well as phosphoric acid in the liquids is concentrated to the initial concentration of the electrolyte in the anode chamber for reuse as the decontaminating electrolyte. As the phosphoric acid extracting agent used in the electrodeposition recovering step for the decontaminating electrolyte, water-insoluble and non-combustible tributyl phosphate (TBP) is most effective. (Horiuchi, T.)

Computer processing techniques in digital radiography research

International Nuclear Information System (INIS)

Pickens, D.R.; Kugel, J.A.; Waddill, W.B.; Smith, G.D.; Martin, V.N.; Price, R.R.; James, A.E. Jr.

1985-01-01

In the Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, and the Center for Medical Imaging Research, Nashville, TN, there are several activities which are designed to increase the information available from film-screen acquisition as well as from direct digital acquisition of radiographic information. Two of the projects involve altering the display of images after acquisition, either to remove artifacts present as a result of the acquisition process or to change the manner in which the image is displayed to improve the perception of details in the image. These two projects use methods which can be applied to any type of digital image, but are being implemented with images digitized from conventional x-ray film. One of these research endeavors involves mathematical alteration of the image to correct for motion artifacts or registration errors between images that will be subtracted. Another applies well-known image processing methods to digital radiographic images to improve the image contrast and enhance subtle details in the image. A third project involves the use of dual energy imaging with a digital radiography system to reconstruct images which demonstrate either soft tissue details or the osseous structures. These projects are discussed in greater detail in the following sections of this communication

Gamma radiography and its technological application; Gammagraphie et techniques annexes

Energy Technology Data Exchange (ETDEWEB)

Courtois, G [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1962-07-01

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

Rare-earth doped phosphors: oldies or goldies?

International Nuclear Information System (INIS)

Moine, B.; Bizarri, G.

2003-01-01

The scientific research on phosphors has a long history starting more than 100 years ago. But recently the appearance of new kinds of displays and lighting devices (plasma display, fluorescent lamp without mercury, etc.) induced an increase of the research of new phosphors with better luminous efficiency than those available up to now. It has been shown that the behavior of 'classical' phosphors in a plasma display panel is quite different than in a cathode ray tube and that the vacuum ultraviolet (VUV) excitation process has to be studied with care in order to improve the phosphors efficiency. That is particularly true in PDPs. It is well established now that a good phosphor for electronic or ultraviolet excitation is not necessarily a good choice for excitation in VUV. This is probably due to the fact that the excitation process is very different in that case and also because the penetration depth of the VUV photons is extremely small inducing a large contribution of the surface of the phosphor. We will illustrate this with some examples. Methods to accelerate luminous intensity decrease under VUV excitation will be described. Low efficiency, fast aging process are both drawbacks that can be solved only in the framework of fundamental studies. Quantum cutting emission may be a solution for the first one but no satisfactory process was proposed for the moment to solve the second

Prevalence and Clinical Import of Thoracic Injury Identified by Chest Computed Tomography but Not Chest Radiography in Blunt Trauma: Multicenter Prospective Cohort Study.

Science.gov (United States)

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

White-electroluminescent device with horizontally patterned blue/yellow phosphor-layer structure

International Nuclear Information System (INIS)

Won Park, Boo; Sik Choi, Nam; Won Park, Kwang; Mo Son, So; Kim, Jong Su; Kyun Shon, Pong

2007-01-01

White-electroluminescent (EL) devices with stripe-patterned and square-patterned phosphor-layer structures are fabricated through a screen printing method: electrode/BaTiO 3 insulator layer/patterned blue ZnS:Cu, Cl and yellow ZnS:Cu, Mn phosphor layer/ITO PET substrate. The luminous intensities of EL devices with stripe-patterned and square-patterned phosphor-layer structures are 33% and 23% higher than a conventional device with the phosphor-layer structure without any patterns using the phosphor blend. It can be explained in terms of the absorption of the emitted blue light of blue phosphor layer by the yellow-emitting phosphor layer. The EL device of our patterned phosphor-layer structure gives the possibility to enhance the luminance

Photoluminescence of phosphors for PDP with VUV excitation

International Nuclear Information System (INIS)

Lu, H.-C.; Chen, H.-K.; Tseng, T.-Y.; Kuo, W.-L.; Alam, M.S.; Cheng, B.-M.

2005-01-01

In a plasma display panel (PDP) He-Xe or Ne-Xe gaseous mixtures are subjected to electric discharge between two glass panels, so to generate VUV light. Red, green and blue phosphors absorb this VUV radiation and re-radiate the energy as visible light to produce the colors that appear on the screen. The phosphor plays an important role in the working of a PDP. To improve the efficiency of phosphors, we have established a photoluminescence end station coupled to the beam line of a synchrotron to study the luminescence of PDP phosphors. This luminescence is analyzed with a 0.32 m monochromator having maximum resolution 0.04 nm, and is monitored with a photomultiplier tube operated in a photon-counting mode. Preliminary data demonstrate the powerful performance of this end-station for studying PDP phosphors

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

Science.gov (United States)

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.

Synthesis and characterization of physical properties of Gd{sub 2}O{sub 2}S:Pr{sup 3+} semi-nanoflower phosphor

Energy Technology Data Exchange (ETDEWEB)

Bagheri, A.; Rezaee Ebrahim Saraee, Kh.; Shakur, H.R. [University of Isfahan, Department of Nuclear Engineering, Faculty of Advance Sciences and Technologies, Isfahan (Iran, Islamic Republic of); Zamani Zeinali, H. [Nuclear Science and Technology Research Institute, Agriculture, Medical and Industrial Research School, Karaj (Iran, Islamic Republic of)

2016-05-15

Pure gadolinium oxysulfide phosphor (Gd{sub 2}O{sub 2}S) and trivalent praseodymium-doped gadolinium oxysulfide phosphor (Gd{sub 2}O{sub 2}S:Pr{sup 3+}) scintillators with semi-nanoflower crystalline structures were successfully synthesized through a precipitation method and subsequent calcination treatment as a converter for X-ray imaging detectors. The characterization such as the crystal structures and nanostructure of Gd{sub 2}O{sub 2}S:Pr{sup 3+} scintillator measured by XRD and FeE-SEM experiment. The optical properties of Gd{sub 2}O{sub 2}S:Pr{sup 3+} scintillator were studied. Luminescence spectra of Gd{sub 2}O{sub 2}S:Pr{sup 3+} under 320 nm UV excitation show a green emission at near 511 nm corresponding to the {sup 3}P{sub 0}-{sup 3}H{sub 4} of Pr ions. After scintillation properties of synthesized Gd{sub 2}O{sub 2}S:Pr{sup 3+} scintillator investigated, Gd{sub 2}O{sub 2}S:Pr{sup 3+} scintillating film fabricated on a glass substrate by a sedimentation method. X-ray imaging of the fabricated scintillators confirmed that the Gd{sub 2}O{sub 2}S:Pr{sup 3+} scintillator could be used for radiography applications in which good spatial resolution is needed. (orig.)

Relationships among measurements obtained by use of computed tomography and radiography and scores of cartilage microdamage in hip joints with moderate to severe joint laxity of adult dogs.

Science.gov (United States)

Lopez, Mandi J; Lewis, Brooke P; Swaab, Megan E; Markel, Mark D

2008-03-01

To evaluate correlations among measurements on radiographic and computed tomography (CT) images with articular cartilage microdamage in lax hip joints of dogs. 12 adult mixed-breed hounds. Pelvic CT and radiography were performed. Hip joints were harvested following euthanasia. Orthopedic Foundation for Animals (OFA) and PennHIP radiograph reports were obtained. Norberg angle (NA) and radiographic percentage femoral head coverage (RPC) were determined. Center-edge angle (CEA), horizontal toit externe angle (HTEA), ventral acetabular sector angle (VASA), dorsal acetabular sector angle (DASA), horizontal acetabular sector angle (HASA), acetabular index (AI), and CT percentage femoral head coverage (CPC) were measured on 2-dimensional CT images. Femoral head-acetabular shelf percentage was measured on sagittal 3-dimensional CT (SCT) and transverse 3-dimensional CT (TCT) images. Light microscopy was used to score joint cartilage. Relationships of OFA confirmation and PennHIP osteoarthritis scores with radiography, CT, and cartilage variables and relationships of cartilage scores with radiography and CT measurements were evaluated with Spearman rank correlations. Pearson correlation was used for relationships of distraction index (DI) with radiography, CT, and cartilage variables. Significant relationships included PennHIP osteoarthritis score with cartilage score, CEA, HTEA, DASA, AI, CPC, and TCT; OFA confirmation score with cartilage score, NA, RPC, CEA, HTEA, DASA, AI, CPC, and TCT; cartilage score with NA, RPC, CEA, HTEA, DASA, HASA, AI, and TCT; and DI with cartilage score, CEA, HTEA, DASA, HASA, AI, and CPC. CT appeared to be a valuable imaging modality for predicting cartilage microdamage in canine hip joints.

Diagnostic Value of Conventional and Digital Radiography for Detection of Cavitated and Non-Cavitated Proximal Caries

Directory of Open Access Journals (Sweden)

Mahdieh Dehghani

2017-02-01

Full Text Available Objectives: This study aimed to assess the diagnostic value of conventional and digital radiography for detection of cavitated and non-cavitated proximal caries.Materials and Methods: Fifty extracted human premolars and molars were mounted in a silicone block. Charge-coupled device (CCD and photostimulable phosphor plate (PSP receptors and intra-oral films were exposed with 60 and 70 kVp with parallel technique. Two observers interpreted the radiographs twice with a two-week interval using a 5-point scale. Teeth were then serially sectioned in mesiodistal direction and evaluated under a stereomicroscope (gold standard. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated.Results: Sensitivity of all three receptors for detection of enamel lesions was low (5.5-44.4% but it was higher for dentin lesions (42.8-62.8%; PSP with 70 kVp and 0.03s exposure time had the highest sensitivity for enamel lesions, but the difference among receptors was not statistically significant (P>0.05. Sensitivity of all three receptors for detection of non-cavitated lesions was lower than that for cavitated lesions; PSP with 60 kVp and 0.07s exposure time had higher sensitivity and lower patient radiation dose for detection of cavitated and non-cavitated lesions, but the difference was not significant (P>0.05.Conclusions: Digital radiography using PSP receptor with 70 kVp is recommended to detect initial enamel caries. For detection of non-cavitated and cavitated dentin caries, PSP with 60 kVp is more appropriate. Change in kVp did not affect the diagnostic accuracy for detection of caries, and type of receptor was a more important factor.Keywords: Dental Caries; Diagnostic Imaging; Radiography, Dental, Digital

High Extraction Phosphors for Solid State Lighting

Energy Technology Data Exchange (ETDEWEB)

Summers, Chris [Phosphortech Corporation, Kennesaw, GA (United States); Menkara, Hisham [Phosphortech Corporation, Kennesaw, GA (United States); Wagner, Brent [Phosphortech Corporation, Kennesaw, GA (United States)

2011-09-01

We have developed high-index, high efficiency bulk luminescent materials and novel nano-sized phosphors for improved solid-state white LED lamps. These advances can potentially contribute to reducing the loss in luminous efficiencies due to scattering, re-absorption, and thermal quenching. The bulk and nanostructured luminescent materials investigated are index matched to GaN and have broad and size-tunable absorption bands, size and impurity tuned emission bands, size-driven elimination of scattering effects, and a separation between absorption and emission bands. These innovations were accomplished through the use of novel synthesis techniques suitable for high volume production for LED lamp applications. The program produced a full-color set of high quantum yield phosphors with high chemical stability. In the bulk phosphor study, the ZnSeS:Cu,Ag phosphor was optimized to achieve >91% efficiency using erbium (Er) and other activators as sensitizers. Detailed analysis of temperature quenching effects on a large number of ZnSeS:Cu,Ag,X and strontium- and calcium-thiogallate phosphors lead to a breakthrough in the understanding of the anti-quenching behavior and a physical bandgap model was developed of this phenomena. In a follow up to this study, optimized phosphor blends for high efficiency and color performance were developed and demonstrated a 2-component phosphor system with good white chromaticity, color temperature, and high color rendering. By extending the protocols of quantum dot synthesis, large nanocrystals, greater than 20 nm in diameter were synthesized and exhibited bulk-like behavior and blue light absorption. The optimization of ZnSe:Mn nanophosphors achieved ~85% QE The limitations of core-shell nanocrystal systems were addressed by investigating alternative deltadoped structures. To address the manufacturability of these systems, a one-pot manufacturing protocol was developed for ZnSe:Mn nanophosphors. To enhance the stability of these material

Electrolyte Additives for Phosphoric Acid Fuel Cells

DEFF Research Database (Denmark)

Gang, Xiao; Hjuler, H.A.; Olsen, C.A.

1993-01-01

, as a fuel-cell performance with the modified electrolytes. Specific conductivity measurements of some of the modified phosphoric acid electrolytes are reported. At a given temperature, the conductivity of the C4F9SO3K-modified electrolyte decreases with an increasing amount of the additive; the conductivity...... of the remains at the same value as the conductivity of the pure phosphoric acid. At a given composition, the conductivity of any modified electrolyte increases with temperature. We conclude that the improved cell performance for modified electrolytes is not due to any increase in conductivity.......Electrochemical characteristics of a series of modified phosphoric acid electrolytes containing fluorinated car on compounds and silicone fluids as additives are presented. When used in phosphoric acid fuel cells, the modified electrolytes improve the performance due to the enhanced oxygen...

High energy neutron radiography

International Nuclear Information System (INIS)

Gavron, A.; Morley, K.; Morris, C.; Seestrom, S.; Ullmann, J.; Yates, G.; Zumbro, J.

1996-01-01

High-energy spallation neutron sources are now being considered in the US and elsewhere as a replacement for neutron beams produced by reactors. High-energy and high intensity neutron beams, produced by unmoderated spallation sources, open potential new vistas of neutron radiography. The authors discuss the basic advantages and disadvantages of high-energy neutron radiography, and consider some experimental results obtained at the Weapons Neutron Research (WNR) facility at Los Alamos

WE-G-209-01: Digital Radiography

Energy Technology Data Exchange (ETDEWEB)

Schueler, B. [Mayo Clinic (United States)

2016-06-15

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 course 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.

Process for winning uranium from wet process phosphoric acid

International Nuclear Information System (INIS)

1980-01-01

A process is described for winning uranium from wet process phosphoric acid by means of liquid-liquid extraction with organic phosphoric acid esters. The process is optimised by keeping the sulphate percentage in the phosphoric acid below 2% by weight, and preferably below 0.6% by weight, as compared to P 2 O 5 in the phosphoric acid. This is achieved by adding an excess of Ba and/or Ca carbonate or sulfide solution and filtering off the formed calcium and/or barium sulphate precipitates. Solid KClO 3 is then added to the filtrate to oxidise U 4+ to U 6+ . The normal extraction procedure using organic phosphoric esters as extraction liquid, can then be applied. (Th.P.)

Evaluation of radiation dose to patients in intraoral dental radiography using Monte Carlo Method

International Nuclear Information System (INIS)

Park, Il; Kim, Kyeong Ho; Oh, Seung Chul; Song, Ji Young

2016-01-01

The use of dental radiographic examinations is common although radiation dose resulting from the dental radiography is relatively small. Therefore, it is required to evaluate radiation dose from the dental radiography for radiation safety purpose. The objectives of the present study were to develop dosimetry method for intraoral dental radiography using a Monte Carlo method based radiation transport code and to calculate organ doses and effective doses of patients from different types of intraoral radiographies. Radiological properties of dental radiography equipment were characterized for the evaluation of patient radiation dose. The properties including x-ray energy spectrum were simulated using MCNP code. Organ doses and effective doses to patients were calculated by MCNP simulation with computational adult phantoms. At the typical equipment settings (60 kVp, 7 mA, and 0.12 sec), the entrance air kerma was 1.79 mGy and the measured half value layer was 1.82 mm. The half value layer calculated by MCNP simulation was well agreed with the measurement values. Effective doses from intraoral radiographies ranged from 1 μSv for maxilla premolar to 3 μSv for maxilla incisor. Oral cavity layer (23⁓82 μSv) and salivary glands (10⁓68 μSv) received relatively high radiation dose. Thyroid also received high radiation dose (3⁓47 μSv) for examinations. The developed dosimetry method and evaluated radiation doses in this study can be utilized for policy making, patient dose management, and development of low-dose equipment. In addition, this study can ultimately contribute to decrease radiation dose to patients for radiation safety

Evaluation of radiation dose to patients in intraoral dental radiography using Monte Carlo Method

Energy Technology Data Exchange (ETDEWEB)

Park, Il; Kim, Kyeong Ho; Oh, Seung Chul; Song, Ji Young [Dept. of Nuclear Engineering, Kyung Hee University, Yongin (Korea, Republic of)

2016-11-15

The use of dental radiographic examinations is common although radiation dose resulting from the dental radiography is relatively small. Therefore, it is required to evaluate radiation dose from the dental radiography for radiation safety purpose. The objectives of the present study were to develop dosimetry method for intraoral dental radiography using a Monte Carlo method based radiation transport code and to calculate organ doses and effective doses of patients from different types of intraoral radiographies. Radiological properties of dental radiography equipment were characterized for the evaluation of patient radiation dose. The properties including x-ray energy spectrum were simulated using MCNP code. Organ doses and effective doses to patients were calculated by MCNP simulation with computational adult phantoms. At the typical equipment settings (60 kVp, 7 mA, and 0.12 sec), the entrance air kerma was 1.79 mGy and the measured half value layer was 1.82 mm. The half value layer calculated by MCNP simulation was well agreed with the measurement values. Effective doses from intraoral radiographies ranged from 1 μSv for maxilla premolar to 3 μSv for maxilla incisor. Oral cavity layer (23⁓82 μSv) and salivary glands (10⁓68 μSv) received relatively high radiation dose. Thyroid also received high radiation dose (3⁓47 μSv) for examinations. The developed dosimetry method and evaluated radiation doses in this study can be utilized for policy making, patient dose management, and development of low-dose equipment. In addition, this study can ultimately contribute to decrease radiation dose to patients for radiation safety.

Neutron radiography at the HFR Petten compilation of HFR Petten contributions to the second world conference on neutron radiography

International Nuclear Information System (INIS)

Markgraf, J.W.F.

1986-01-01

This booklet summarizes the six papers on neutron radiography activities at the Petten High Flux Reactor (HFR), presented at the Second World Conference on neutron radiography, held in June 1986 in Paris, France. The conference was organized by the French CEA and COFREND, and JRC Petten, HFR Division, with joint sponsorship of the national societies on Non-Destructive Testing (NDT) from the Federal Republic of Germany, United Kingdom, Japan and the United States. The Petten papers are concerned with: (i) the work of the Neutron Radiography Working Group (NRWG), an expert group operating under the auspices of the Commission of the European Communities represented by JRC Petten, HFR Division; (ii) applications of neutron radiography in research programmes performed at HFR; (iii) neutron radiography facilities at HFR; and (iv) image evaluation techniques

A range of equipment for dental radiography

International Nuclear Information System (INIS)

Bergman, G.P.M.; Clement, S.L.

1980-01-01

A brief review of the history of dental radiography is followed by a description of the latest Philips equipment, ranging from compact units for intra-oral radiography to advanced systems for panoramic techniques and skull radiography. The advantages of automatic exposure control and automatic film processing are also discussed. In conclusion, some probable future trends are forecast. (Auth.)

Scaling Up: Kilolumen Solid-State Lighting Exceeding 100 LPW via Remote Phosphor

Energy Technology Data Exchange (ETDEWEB)

Waqidi Falicoff

2008-09-15

similar light bulbs. In Phase II several new reflective remote phosphor systems were developed and patents applied for. This research included the development of reflective systems in which the short-pass filter operated at a nominal incidence angle of 15{sup o}, a major advancement of this technology. Another goal of the project was to show that it is possible to align multiple optics to multiple LEDs (spaced apart for better thermal management) to within an accuracy in the z-direction of 10 microns or less. This goal was achieved. A further goal was to show it is possible to combine and homogenize the output from multiple LEDs without any flux loss or significant increase in etendue. This goal also was achieved. The following color-coded computer drawing of the Phase 2 reflective remote phosphor prototype gives an idea of the accuracy challenges encountered in such an assembly. The actual setup has less functional clarity due to the numerous items of auxiliary equipment involved. Not only did 10 degrees of freedoms alignment have to be supplied to the LEDs and component prisms as well, but there were also micro-titrating glue dispensers and vacuum hoses. The project also utilized a recently introduced high-index glass, available in small customized prisms. This prototype also embodies a significant advance in thin-film design, by which an unprecedented 98% single-pass efficiency was attained over a 30 degree range of incidence angle (Patents Pending). Such high efficiency is especially important since it applies to the blue light going to the phosphor and then again to the phosphor's light, so that the 'system' efficiency associated with short-pass filter was 95.5%. Other losses have to be kept equally small, towards which a new type of ultra-clear injection-moldable acrylic was discovered and used to make ultra-transparent CPC optics. Several transmissive remote phosphor prototypes were manufactured that could replace screw-in type incandescent bulbs

Imaging of bone tumors: evaluation of direct magnification radiography

International Nuclear Information System (INIS)

Link, T.M.; Hillmann, A.; Erlemann, R.; Groenefeld, A.; Haeussler, M.; Heppe, A.E.; Vestring, T.; Peters, P.E.

1996-01-01

Objective. To evaluate the potentials of magnification radiography as compared with conventional radiography in diagnosing bone tumors. Design and patients. Sixty-two patients with primary bone tumors and tumorlike lesions underwent radiography with both conventional (non-magnified) and magnification (fivefold) techniques. All radiographs were analyzed by four radiologists and the findings correlated with the histopathology findings. The microfocal X-ray unit used for magnification radiography had a focal spot size of 20-130 μm. Digital luminescence radiography was employed with magnification, while normal film-screen systems were used with conventional radiography. Results. The diagnosis of benign and malignant lesions as well as the individual tumor diagnosis were determined with higher accuracy using magnification compared with conventional radiography (88% vs 75% and 71% vs 52%, p<0.01). Margins of destruction, periosteal reactions and matrix patterns were evaluated with higher certainty by all of the radiologists (p<0.01). Conclusion. Magnification radiography may improve the evaluation and diagnosis of bone tumors. (orig.). With 6 tabs

Industrial Radiography | Radiation Protection | US EPA

Science.gov (United States)

2017-08-07

Manufacturers use a method called industrial radiography to check for cracks or flaws in materials. Radiation is used in industrial radiography to show problems not visible from the outside without damaging the material.

Artifacts in digital radiography

International Nuclear Information System (INIS)

Min, Jung Whan; Kim, Jung Min; Jeong, Hoi Woun

2015-01-01

Digital Radiography is a big part of diagnostic radiology. Because uncorrected digital radiography image supported false effect of Patient’s health care. We must be manage the correct digital radiography image. Thus, the artifact images can have effect to make a wrong diagnosis. We report types of occurrence by analyzing the artifacts that occurs in digital radiography system. We had collected the artifacts occurred in digital radiography system of general hospital from 2007 to 2014. The collected data had analyzed and then had categorize as the occurred causes. The artifacts could be categorized by hardware artifacts, software artifacts, operating errors, system artifacts, and others. Hardware artifact from a Ghost artifact that is caused by lag effect occurred most frequently. The others cases are the artifacts caused by RF noise and foreign body in equipments. Software artifacts are many different types of reasons. The uncorrected processing artifacts and the image processing error artifacts occurred most frequently. Exposure data recognize (EDR) error artifacts, the processing error of commissural line, and etc., the software artifacts were caused by various reasons. Operating artifacts were caused when the user did not have the full understanding of the digital medical image system. System artifacts had appeared the error due to DICOM header information and the compression algorithm. The obvious artifacts should be re-examined, and it could result in increasing the exposure dose of the patient. The unclear artifact leads to a wrong diagnosis and added examination. The ability to correctly determine artifact are required. We have to reduce the artifact occurrences by understanding its characteristic and providing sustainable education as well as the maintenance of the equipments

Artifacts in digital radiography

Energy Technology Data Exchange (ETDEWEB)

Min, Jung Whan [Dept. of Radiological Technology, Shin Gu University, Sungnam (Korea, Republic of); Kim, Jung Min [Dept. of Radiological Technology, Korea University, Seoul (Korea, Republic of); Jeong, Hoi Woun [Dept. of Radiological Technology, Beakseok Culture University, Cheonan (Korea, Republic of)

2015-12-15

Digital Radiography is a big part of diagnostic radiology. Because uncorrected digital radiography image supported false effect of Patient’s health care. We must be manage the correct digital radiography image. Thus, the artifact images can have effect to make a wrong diagnosis. We report types of occurrence by analyzing the artifacts that occurs in digital radiography system. We had collected the artifacts occurred in digital radiography system of general hospital from 2007 to 2014. The collected data had analyzed and then had categorize as the occurred causes. The artifacts could be categorized by hardware artifacts, software artifacts, operating errors, system artifacts, and others. Hardware artifact from a Ghost artifact that is caused by lag effect occurred most frequently. The others cases are the artifacts caused by RF noise and foreign body in equipments. Software artifacts are many different types of reasons. The uncorrected processing artifacts and the image processing error artifacts occurred most frequently. Exposure data recognize (EDR) error artifacts, the processing error of commissural line, and etc., the software artifacts were caused by various reasons. Operating artifacts were caused when the user did not have the full understanding of the digital medical image system. System artifacts had appeared the error due to DICOM header information and the compression algorithm. The obvious artifacts should be re-examined, and it could result in increasing the exposure dose of the patient. The unclear artifact leads to a wrong diagnosis and added examination. The ability to correctly determine artifact are required. We have to reduce the artifact occurrences by understanding its characteristic and providing sustainable education as well as the maintenance of the equipments.

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

Science.gov (United States)

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

2014-02-01

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

Comparison of the new and the used imaging plates on computed radiography

International Nuclear Information System (INIS)

Ding Weihong; Zhang Weimin; Wang Jiawei

2008-01-01

Objective: To compare image quality and radiation dose of the new imaging plate (IP) with the used IP on computed radiography (CR), and to investigate the using principle in the two kinds of IP. Methods: The dark noise, uniformity and erasure thoroughness of the new and the used IP were measured respectively. Based on threshold contrast-detail detectability (TCCD) technique, the phantom TO, 16 photography was done at 75 kV, and with the two kinds of IP respectively. Three observers scored each image sequence using double blind method, calculated the threshold detection index (H T ). The volunteers were randomly divided into three groups: the knee joint group, the chest group and the lumbar group. Each group had 50 cases and checked with the same condition as the phantom. Three radiologists using double blind method evaluated the imaging quality of knee joint, chest and lumbar. Results: The physical characteristic indexes of the new and the used IP were similar to each other. Under the same condition, the detection ability of the new IP was better than that of the used one. When the dose of exposure was raised about 20%, the detection ability of the used IP was close to that of the new one. Conclusions: The dose of exposure can be raised to keep the same imaging quality with the increase times of IP used. The detection ability of IP can decrease with the same dose as before, and the image quality decreases too. (authors)

Analisis gambaran histogramdan densitas kamar pulpa pada gigi suspek pulpitis reversibel dan ireversibel dengan menggunakan radiografi cone beam computed tomography (Histogram and density analysis of irreversible and reversible pulpitissuspected tooth using cone beam computed tomography radiography)

OpenAIRE

Lusi Epsilawati; Suhardjo Sitam; Sam Belly; Fahmi Oscandar

2014-01-01

Inflammation of the pulp is most common and difficult to diagnose. For it radiographs is necessary. One attempt to do is to assess its histogram and density. Radiography equipment that has the ability to analyze is cone beam computed tomography (CBCT). The purpose of this study is to analyze radiograph of the pulp chamber histogram: peak value, grayscale and trends , as well as the density on the condition reversible and irreversible pulpitis condition. The population of this ...

Neutron induced electron radiography

International Nuclear Information System (INIS)

Andrade, Marcos Leandro Garcia

2008-01-01

In the present paper a new radiography technique, the 'Neutron Induced Electron Radiography' - NIER, to inspect low thickness samples on the order of micra, has been developed. This technique makes use of low energy electrons as penetrating radiation generated from metallic gadolinium screens when irradiated by thermal neutrons. The conditions to obtain the best image for the conventional X-ray film Kodak-AA were determined by using a digital system to quantify the darkening level of the film. The irradiations have been performed at a radiography equipment installed at the beam-hole no. 8 of the 5 MW IEA-R1 nuclear research reactor of IPEN-CNEN/SP. The irradiation time to obtain the best radiography was 100 seconds and for such condition the technique was able to discern 1 μm in 24 μm of aluminum at a resolution of 32 μm. By visual comparison the images obtained by the NIER shown a higher quality when compared with the ones from other usual techniques the make use of electrons a penetrating radiation and films for image registration. Furthermore the use of the digital system has provided a smaller time for data acquisition and data analysis as well as an improvement in the image visualization. (author)

The advantages of digital radiography in department of radiology

International Nuclear Information System (INIS)

Mao Lijuan; Luo Xiaomei; Wu Tengfang

2009-01-01

Objective: To investigate the advantages of digital radiography in department of radiology by comparing digital radiography with common radiography. Methods: Test card was used for testing the spatial resolution of DR and common radiography. 1000 films of chest by DR and 1000 films of chest by common radiography were compared in image quality, dose of radiation, the rate of waste film, and the advantages of DR was analyzed. Results: Compared to common radiography, DR had a high sensitivity, high DQE (quantum detection efficiency), high spatial resolution and density resolution. The speed of acquisition and X-ray conversion efficiency were fast. The function of post-processing was strong and the rate of disease detection was high. Conclusion: DR is better than common radiography in all respects, it will be widely applied. (authors)

Chest radiography after minor chest trauma

Energy Technology Data Exchange (ETDEWEB)

Rossen, B.; Laursen, N.O.; Just, S.

The results of chest radiography in 581 patients with blunt minor thoracic trauma were reviewed. Frontal and lateral views of the chest indicated pathology in 72 patients (12.4%). Pneumothorax was present in 16 patients; 4 had hemothorax. The physical examination and the results of chest radiography were not in accordance because in 6(30%) of the 20 patients with hemo/-pneumothorax the physical examination was normal. Consequently there is wide indication for chest radiography after minor blunt chest trauma.

Chest radiography after minor chest trauma

International Nuclear Information System (INIS)

Rossen, B.; Laursen, N.O.; Just, S.

1987-01-01

The results of chest radiography in 581 patients with blunt minor thoracic trauma were reviewed. Frontal and lateral views of the chest indicated pathology in 72 patients (12.4%). Pneumothorax was present in 16 patients; 4 had hemothorax. The physical examination and the results of chest radiography were not in accordance because in 6(30%) of the 20 patients with hemo/-pneumothorax the physical examination was normal. Consequently there is wide indication for chest radiography after minor blunt chest trauma. (orig.)

Phosphate phosphors for solid-state lighting

Energy Technology Data Exchange (ETDEWEB)

Shinde, Kartik N. [N.S. Science and Arts College, Bhadrawati (India). Dept. of Physics; Swart, H.C. [University of the Orange Free State, Bloemfontein (South Africa). Dept. of Physics; Dhoble, S.J. [R.T.M. Nagpur Univ. (India). Dept. of Physics; Park, Kyeongsoon [Sejong Univ., Seoul (Korea, Republic of). Faculty of Nanotechnology and Advanced Materials Engineering

2012-07-01

Essential information for students in researchers working towards new and more efficient solid-state lighting. Comprehensive survey based on the authors' long experience. Useful both for teaching and reference. The idea for this book arose out of the realization that, although excellent surveys and a phosphor handbook are available, there is no single source covering the area of phosphate based phosphors especially for lamp industry. Moreover, as this field gets only limited attention in most general books on luminescence, there is a clear need for a book in which attention is specifically directed toward this rapidly growing field of solid state lighting and its many applications. This book is aimed at providing a sound introduction to the synthesis and optical characterization of phosphate phosphor for undergraduate and graduate students as well as teachers and researchers. The book provides guidance through the multidisciplinary field of solid state lighting specially phosphate phosphors for beginners, scientists and engineers from universities, research organizations, and especially industry. In order to make it useful for a wide audience, both fundamentals and applications are discussed, together.

Representability of metastatic bone lesions in magnification radiography

International Nuclear Information System (INIS)

Togawa, Takashi

1981-01-01

Magnification radiography, bone scintigraphy, and normal roentgenography were performed on patients with malignant tumors to detect their bone metastases, and from the results obtained, these diagnostic procedures were evaluated for the detectability and representability of metastatic bone lesions. Bone scan and normal roentgenography were performed on 90 metastatic bone lesions in 37 patients, and magnification radiography was done on 14 bone lesions noted in 10 of the 37 and another with benign osseous change. Among the three, bone scintigraphy was best, and magnification radiography and normal roentgenography did not differ significantly in detectability. In magnification radiography, some metastatic bone lesions were represented more clearly than by normal roentgeography, but some were not. As regards the representability of the ribs, magnification radiography was very useful. One case of bone destruction was detected by magnification radiography, but not by normal roentgenography. (author)

Process waste assessment for the Radiography Laboratory

International Nuclear Information System (INIS)

Phillips, N.M.

1994-07-01

This Process Waste Assessment was conducted to evaluate the Radiography Laboratory, located in Building 923. It documents the processes, identifies the hazardous chemical waste streams generated by these processes, recommends possible ways to minimize waste, and serves as a reference for future assessments of this facility. The Radiography Laboratory provides film radiography or radioscopy (electronic imaging) of weapon and nonweapon components. The Radiography Laboratory has six x-ray machines and one gamma ray source. It also has several other sealed beta- and gamma-ray isotope sources of low microcurie (μCi) activity. The photochemical processes generate most of the Radiography Laboratory's routinely generated hazardous waste, and most of that is generated by the DuPont film processor. Because the DuPont film processor generates the most photochemical waste, it was selected for an estimated material balance

Contribution of computed tomography in patients with lung metastases of differentiated thyroid carcinoma not apparent on plain radiography who were treated with radioiodine

International Nuclear Information System (INIS)

Rosario, Pedro W.S.; Purisch, Saulo; Barroso, Alvarao L.; Rezende, Leonardo L.; Padrao, Eduardo L.

2008-01-01

Computed tomography (CT or CAT Scan) of the chest is more sensitive than radiography in the detection of lung metastases of differentiated thyroid cancer (DTC), but little information is available regarding the aggregated value of this method. The present study evaluated the response of patients with lung metastases of DTC not apparent on radiography to treatment with 131 I and the value of CT in these cases. Twenty-five patients with lung metastases not apparent on radiography, who initially received 100-200 mCi I 151 , were evaluated and those presenting pulmonary uptake on post-therapy WBS were submitted to a new treatment after 6 to 12 months, and so on. The chance of detection of pulmonary uptake on post-therapy WBS did not differ between patients with negative and positive CT (100% versus 91.5%). Mean serum Tg levels were higher in patients with positive CT (108 ng/ml versus 52 ng/ml). Negative post-therapy WBS was achieved in 82% of patients with positive CT and in 92.3% with negative CT and the cumulative I 131 activity necessary to achieve this outcome did not differ between the two groups (mean = 300 mCi). Stimulated Tg was undetectable in 47% of patients with negative CT at the end of treatment, but in none of the patients whose CT continued to be positive. In patients with elevated Tg, the CT result apparently did not change the indication of therapy or the I 131 activity to be administered. In cases with lung metastases, the persistence of micronodules on CT was associated with the persistence of detectable Tg in patients presenting negative post-therapy WBS. (author)

Computed tomography scout views vs. conventional radiography in body-packers – Delineation of body-packs and radiation dose in a porcine model

Energy Technology Data Exchange (ETDEWEB)

Ziegeler, Edvard, E-mail: edvard.ziegeler@campus.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany); Grimm, Jochen M., E-mail: jochen.grimm@med.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany); Wirth, Stefan, E-mail: tefan.wirth@med.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany); Uhl, Michael, E-mail: michael.uhl@polizei.bayern.de [Bavarian State Criminal Police Office, Maillingerstrasse 15, 80636 Munich (Germany); Reiser, Maximilian F., E-mail: Maximilian.Reiser@med.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany); Scherr, Michael K., E-mail: Michael.Scherr@med.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany)

2012-12-15

Objective: To compare abdominal computed tomography (CT) scout views with conventional radiography regarding radiation dose and delineation of drug packages in a porcine body-packer model. Materials and methods: Nine samples of illicit drugs packed in ovoid plastic containers were consecutively placed in the rectum of a 121.5 kg pig cadaver. Antero-posterior and lateral scout views were obtained at 120 kVp and 80 mA, 150 mA and 200 mA, respectively, using a 64-row MDCT. Scout views were compared with conventional abdominal antero-posterior radiographs (77 kV and 106 ± 13 mAs). Visibility of three body pack characteristics (wrapping, content, shape) was rated independently by two radiologists and summarized to a delineation score ranging from 0 to 9 with a score ≥6 representing sufficient delineation. Mean delineation scores were calculated for each conventional radiography and single plane scout view separately and for a combined rating of antero-posterior and lateral scout views. Results: Even the lowest single plane scout view delineation score (5.3 ± 2.0 for 80 mA lateral; 0.4 mSv; sensitivity = 44%) was significantly higher than for conventional radiographs (3.1 ± 2.5, p < 0.001; 2.4 ± 0.3 mSv; sensitivity = 11%). Combined reading of antero-posterior and lateral scout views 80 mA yielded sufficient delineation (6.2 ± 1.4; 0.8 mSv; sensitivity = 56%). Conclusions: All CT scout views showed significantly better delineation ratings and sensitivity than conventional radiographs. Scout views in two planes at 80 mA provided a sufficient level of delineation and a sensitivity five times higher than conventional radiography at less than one third of the radiation dose. In case of diagnostic insecurity, CT can be performed without additional logistical effort.

Spatially coded backscatter radiography