WorldWideScience

Sample records for body essential x-ray

  1. X-ray inspection of foreign bodies in foods

    International Nuclear Information System (INIS)

    Ohira, Norihiro; Hongjun, Zhou; Sakamaki, Kazumi; Kamimura, Kunio; Shimizu, Hideaki; Saiki, Hideo

    2008-01-01

    X-ray inspection system of foreign bodies in foods has become is necessary for our society in recent years, with the expectation that they could inspect not only metals but also other bodies like glass, rubber, nylon, etc. Calculation algorithms for X-ray inspection of foreign bodies in foods have been reported. In food inspection systems, it is important that inspection is high precision, with high speed that is as fast as conveyor belts. Using Statistical methods, we construct a higher precision method than usual methods. We focused on Kittler's minimum error thresholding. In the usual Kittler's method, order n-squared calculations are required for distributed calculation, so it is not suitable for high speed food inspection. We find that using approximations of variances in Kittler's method is not too critical for practical use. Using it, we be come able to inspect for foreign bodies that were not able to be inspected for so far. (author)

  2. Rigid body essential X-ray crystallography

    DEFF Research Database (Denmark)

    Bjerrum, Esben Jannik; Biggin, Philip C

    2008-01-01

    The ligand-binding domain (LBD) from the ionotropic glutamate receptor subtype 2 (GluR2) has been shown to adopt a range of ligand-dependent conformational states. These states have been described in terms of the rotation required to fit subdomain (lobe) 2 following superposition of subdomain (lo...

  3. SCT-4800T whole body X-ray CT scanner

    International Nuclear Information System (INIS)

    Okumura, Yoshitaka; Sato, Yukio; Kuwahara, Hiroshi

    1994-01-01

    A whole body X-ray CT scanner, the SCT-4800T (trade name: INTELLECT series), has been developed. This system is the first CT scanner that is combined with general radiographic functions. The general radiographic functions include a patient couch with film casette and several tube support systems along with the CT scanner. This newly designed CT scanner also features a compact and light-weight gantry with a 700 mm diameter apperture and user-friendly operater's console. The SCT-4800T brings a new level of patient and operator comfort to the emergency radiology examination site. (author)

  4. CubeSAT X-ray Telescope (CubeX) for Elemental Abundance Mapping of Airless Bodies and X-ray Pulsar Navigation (XNAV)

    Science.gov (United States)

    Romaine, S.; Hong, J.; Elvis, M.

    2017-09-01

    The CubeSAT X-ray Telescope (CubeX) is a concept for a 12U planetary X-ray telescope, which utilizes Miniature Wolter-I X-ray optics (MiXO) and a combination of X-ray CMOS and SDD sensors for the focal plane. CubeX will map the surface elemental composition of diverse airless bodies using X-ray Fluorescence (XRF), which can help us to understand the formation and evolutionary history of the individual bodies and the workings of the Solar system as a whole. CubeX will also conduct a feasibility and performance test of X-ray pulsar timing based deep space navigation (XNAV), which can lower operation costs of space navigation and enable autonomous deep space navigation.

  5. Whole body x-ray CT scanner, TCT-900S

    International Nuclear Information System (INIS)

    Mori, Issei; Saito, Kiyoto; Asahina, Kiyotaka

    1987-01-01

    The fundamental parameters of an X-ray CT (computed tomography) scanner are temporal, spatial, and density resolution. Research projects to improve these parameters had reached a standstill until recently. Toshiba has achieved a breakthrough with the development of a new CT system, the TCT-900S, which incorporates a new scanning configuration and several technological improvements. The TCT-900S is already in clinical use in many hospitals nationwide, and new diagnostic applications are being explored. (author)

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

    International Nuclear Information System (INIS)

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

    2017-01-01

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

  7. X-ray microanalysis of electron-dense bodies in Cladosporium resinae

    International Nuclear Information System (INIS)

    Hobbs, G.; Griffiths, A.J.; Hann, A.O.C.

    1986-01-01

    One of the structural changes which occur in Cladosporium resinae during growth on hydrocarbons is the formation of electron-dense bodies. In this paper we report the results of X-ray microanalysis and X-ray mapping, which have shown that these bodies are associated with high concentrations of calcium and phosphorus. Such accumulation of these elements is probably a reflection of the low growth rates which appear to be characteristic of growth of C. resinae on hydrocarbons. (Auth.)

  8. X-ray dark-field imaging for detection of foreign bodies in food

    DEFF Research Database (Denmark)

    Nielsen, Mikkel Schou; Lauridsen, Torsten; Feidenhans'l, Robert Krarup

    2013-01-01

    Conventional X-ray transmission radiography has long been used for online detection of foreign bodies in food products relying on the absorption contrast between the foreign body and food product. In this paper, we present a novel approach for detection of organic foreign bodies such as paper...... and insects in two food products using X-ray dark-field imaging with a grating interferometer. The ability to detect the foreign bodies is quantified using a measure of the contrast-to-noise ratio....

  9. Measurement of body composition in cats using computed tomography and dual energy X-ray absorptiometry

    DEFF Research Database (Denmark)

    Buelund, Lene E; Nielsen, Dorte H; McEvoy, Fintan

    2011-01-01

    Dual energy X-ray absorptiometry (DEXA) is a reference method for assessing body composition but is seldom `accessible in veterinary settings. Computed tomography (CT) can provide similar body composition estimates and we propose that it can be used in body composition studies in animals. We...

  10. Dosimetry for total body irradiation of rhesus monkeys with 300 kV X- rays

    NARCIS (Netherlands)

    Zoetelief, J.; Wagemaker, G.; Broerse, J.J.

    1998-01-01

    Purpose: To obtain more accurate information on the dose distribution in rhesus monkeys for total body irradiation with orthovoltage X-rays. Materials and methods: Dose measurements were performed with an ionization chamber inside homogeneous cylindrical and rectangular phantoms of various

  11. Validity of dual X-ray absorptiometry scanning for determination of body composition in IDDM patients

    DEFF Research Database (Denmark)

    Rosenfalck, A M; Almdal, T; Gotfredsen, A

    1995-01-01

    Data on body composition in patients with insulin-dependent diabetes mellitus (IDDM) are scarce. Dual X-ray absorptiometry (DXA) scanning has proved useful for this purpose in other groups of patients. We tested the validity of the DXA scanner for the determination of fat-free mass (FFM) and fat ...

  12. Image combination enhancement method for X-ray compton back-scattering security inspection body scanner

    International Nuclear Information System (INIS)

    Wang Huaiying; Zhang Yujin; Yang Lirui; Li Dong

    2011-01-01

    As for X-ray Compton Back-Scattering (CBS) body scanner, image clearness is very important for the performance of detecting the contraband hidden on the body. A new image combination enhancement method is provided based on characteristics of CBS body images and points of human vision. After processed by this method, the CBS image will be obviously improved with clear levels, distinct outline and uniform background. (authors)

  13. CubeX: The CubeSAT X-ray Telescope for Elemental Abundance Mapping of Airless Bodies and X-ray Pulsar Navigation

    Science.gov (United States)

    Nittler, L. R.; Hong, J.; Kenter, A.; Romaine, S.; Allen, B.; Kraft, R.; Masterson, R.; Elvis, M.; Gendreau, K.; Crawford, I.; Binzel, R.; Boynton, W. V.; Grindlay, J.; Ramsey, B.

    2017-12-01

    The surface elemental composition of a planetary body provides crucial information about its origin, geological evolution, and surface processing, all of which can in turn provide information about solar system evolution as a whole. Remote sensing X-ray fluorescence (XRF) spectroscopy has been used successfully to probe the major-element compositions of airless bodies in the inner solar system, including the Moon, near-Earth asteroids, and Mercury. The CubeSAT X-ray Telescope (CubeX) is a concept for a 6U planetary X-ray telescope (36U with S/C), which utilizes Miniature Wolter-I X-ray optics (MiXO), monolithic CMOS and SDD X-ray sensors for the focal plane, and a Solar X-ray Monitor (heritage from the REXIS XRF instrument on NASA's OSIRIS-REx mission). CubeX will map the surface elemental composition of diverse airless bodies by spectral measurement of XRF excited by solar X-rays. The lightweight ( 1 kg) MiXO optics provide sub-arcminute resolution with low background, while the inherently rad-hard CMOS detectors provide improved spectral resolution ( 150 eV) at 0 °C. CubeX will also demonstrate X-ray pulsar timing based deep space navigation (XNAV). Successful XNAV will enable autonomous deep navigation with little to no support from the Deep Space Network, hence lowering the operation cost for many more planetary missions. Recently selected by NASA Planetary Science Deep Space SmallSat Studies, the first CubeX concept, designed to rideshare to the Moon as a secondary spacecraft on a primary mission, is under study in collaboration with the Mission Design Center at NASA Ames Research Center. From high altitude ( 6,000 km) frozen polar circular orbits, CubeX will study > 8 regions ( 110 km) of geological interest on the Moon over one year to produce a high resolution ( 2-3 km) elemental abundance map of each region. The novel focal plane design of CubeX also allows us to evaluate the performance of absolute navigation by sequential observations of several

  14. A study of some technical essentials of X-ray mammography

    International Nuclear Information System (INIS)

    Cao Houde; Jiang Qin

    2000-01-01

    Objective: To improve the quality of mammography and diagnostic accuracy by analyzing and studying some of the technical essentials of X-ray mammography. Methods: The mammography quality of 21 hospitals were investigated. The image quality of normal intensifying screen-film combination was tested and compared with computerized mammography. The filming positions and operating skills were studied. Results: The important mammography details that were displayed have low conformity with the diagnostic requirements, mainly due to non-conformity of these equipment to the requirements. The optimal pressure suitable for mammography of the Chinese women was around 12 kg. Conclusion: Necessary attention must be paid to the improvement of imaging features of these equipment. The improved operating skills will greatly raise the detecting percentage of pathological changes of breasts

  15. Automatic vertebral bodies detection of x-ray images using invariant multiscale template matching

    Science.gov (United States)

    Sharifi Sarabi, Mona; Villaroman, Diane; Beckett, Joel; Attiah, Mark; Marcus, Logan; Ahn, Christine; Babayan, Diana; Gaonkar, Bilwaj; Macyszyn, Luke; Raghavendra, Cauligi

    2017-03-01

    Lower back pain and pathologies related to it are one of the most common results for a referral to a neurosurgical clinic in the developed and the developing world. Quantitative evaluation of these pathologies is a challenge. Image based measurements of angles/vertebral heights and disks could provide a potential quantitative biomarker for tracking and measuring these pathologies. Detection of vertebral bodies is a key element and is the focus of the current work. From the variety of medical imaging techniques, MRI and CT scans have been typically used for developing image segmentation methods. However, CT scans are known to give a large dose of x-rays, increasing cancer risk [8]. MRI can be substituted for CTs when the risk is high [8] but are difficult to obtain in smaller facilities due to cost and lack of expertise in the field [2]. X-rays provide another option with its ability to control the x-ray dosage, especially for young people, and its accessibility for smaller facilities. Hence, the ability to create quantitative biomarkers from x-ray data is especially valuable. Here, we develop a multiscale template matching, inspired by [9], to detect centers of vertebral bodies from x-ray data. The immediate application of such detection lies in developing quantitative biomarkers and in querying similar images in a database. Previously, shape similarity classification methods have been used to address this problem, but these are challenging to use in the presence of variation due to gross pathology and even subtle effects [1].

  16. Validity of dual X-ray absorptiometry scanning for determination of body composition in IDDM patients

    DEFF Research Database (Denmark)

    Rosenfalck, A M; Almdal, T; Gotfredsen, A

    1995-01-01

    Data on body composition in patients with insulin-dependent diabetes mellitus (IDDM) are scarce. Dual X-ray absorptiometry (DXA) scanning has proved useful for this purpose in other groups of patients. We tested the validity of the DXA scanner for the determination of fat-free mass (FFM) and fat...... mass in IDDM patients and control subjects, as compared to other reference methods, i.e. total body potassium by 40K whole body counting (TBK), total body water by tritiated water (TBW), bioelectrical impedance analysis (BIA) and 24-h urinary creatinine excretion (Ucrea). A total of 13 healthy controls...

  17. X-ray (image)

    Science.gov (United States)

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

  18. Some peculiarities of the X-ray image of foreign bodies in the stomach

    International Nuclear Information System (INIS)

    Georgieva, S.; Chernev, I.; Khubenski, S.; Palikarski, S.; Naraliev, V.

    1991-01-01

    17 patient swallowed wooden objects have been observed. After abdomenoscopy a conventional X-ray study of the stomach has been made by routine contrast technique in polypositional conditions and fractionated resorption of the contrast matter and fixed creeping compression. A periodical control of the foreign body movement in distal direction is made. The following specific features of the X-ray image are pointed out: the presence of fluid and mucus in an empty hypotonic stomach; progressive intensifying hypotonia of the stomach; gradually increase of the fluid. In recumbent position the foreign bodies show a negative density of respective forms and size. In errect position they 'float' over the contrast matter against the background of the air bubble of the fornix, showing a positive-negative density. When staying for a longer time in the stomach their volume shows a moderate increase. Experimental investigations in-vitro with the same wooden bodies show certain differences in the X-ray image compared to one observed in-vivo, which is due to the presence of fluid and mucus in the stomach. 3 figs., 15 refs

  19. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... of knee x-rays. A portable x-ray machine is a compact apparatus that can be taken ... of the body being examined, an x-ray machine produces a small burst of radiation that passes ...

  20. STUDY OF TIME LAPSE IN FOREIGN BODY ASPIRATION IN RELATION TO CHEST X - RAY AND TYPE OF FOREIGN BODY

    Directory of Open Access Journals (Sweden)

    Salma

    2015-10-01

    Full Text Available INTRODUCTI ON: Foreign body aspiration in pediatrics is a potentially fatal accident which will continue until children explore their surroundings with their hand and mouth. Pediatric aspirations will persist until mankind exists. Not all foreign body aspirations are witnessed hence chances of delay in diagnosing an aspiration are high. Delay in diagnosis depends on site and character of foreign body aspirated. The chest x - ray findings and type of foreign body extracted vary depending on the duration the foreign body remains in airway . OBJECTIVE: To study the X - ray finding in pediatric airway aspiration and its relation to time lapse, the type and site of lodgment of foreign body extracted via bronchoscopy. The type of foreign body in relation to time lapse in aspiration. MATERIAL AND METHODS: This was a prospective study done in Bapuji child health institute and research center, JJM Medical College, Davangere . History and pre bronchoscopy x - Ray finding were noted for 65 children who were posted for suspicious bronchoscopy from August 2011 to September 2013. 11 children were excluded from study as they showed no foreign body on bronchoscopy. Time lapse in aspir ation and seeking medical care was noted. The bronchoscopic findings regarding site of foreign body lodgment and type of foreign body were recorded. The type of foreign body and variation of x - ray picture in relation to time lapse in aspiration were noted. Data collected was analyzed using descriptive statistics. RESULT: It was observed that mean age was 28 months. About 80% of the cases were between 1 to 3 years age. 82% (n=53/54 were radio lucent foreign body, only 1.5% (n=1/54 were radio o paque. Site of lodgment of foreign body was right main bronchus in 48% (n=26/54, left main bronchus 46% (n=25/54 , tracheal 1.85% (n=1/54, subglottic 1.85% (n=1/54, carinal 1.85% (n=1/54, multiple site i.e. left bronchus +right bronchus+ carinal 1.85% (n=1/54. Groundnut was most common

  1. Neural induced embryoid bodies present high levels of metals detected by x-ray microfluorescence

    International Nuclear Information System (INIS)

    Stelling, Mariana P.; Cardoso, Simone C.; Paulsen, Bruna S.; Rehen, Stevens K.

    2012-01-01

    Molecular mechanisms driving neural differentiation in human embryonic stem cells are not completely elucidated, specially, the role of atomic elements within this process. In this work, we described the distribution of trace elements in those stem cells growing as embryoid bodies by using synchrotron radiation X-ray microfluorescence (SR-XRF). Naive and neural induced embryoid bodies derived from embryonic stem cells were irradiated with a spatial resolution of 20 μm to make elemental maps and qualitative chemical analyses. We consistently detected metallic elements content raise on neural induced embryoid bodies, mimicking characteristic brain development. The use of SR-XRF reveals that human embryoid bodies exhibit self-organization at the atomic level, which is enhanced during neurogenesis triggered in vitro.

  2. Neural induced embryoid bodies present high levels of metals detected by x-ray microfluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Stelling, Mariana P.; Cardoso, Simone C.; Paulsen, Bruna S.; Rehen, Stevens K. [Instituto de Ciencias Biomedicas, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas, 373 (Brazil); Instituto de Fisica, Universidade Federal do Rio de Janeiro, Av. Athos da Silveira Ramos, 14, 21941 Rio de Janeiro (Brazil); Instituto de Ciencias Biomedicas, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas, 373 (Brazil)

    2012-05-17

    Molecular mechanisms driving neural differentiation in human embryonic stem cells are not completely elucidated, specially, the role of atomic elements within this process. In this work, we described the distribution of trace elements in those stem cells growing as embryoid bodies by using synchrotron radiation X-ray microfluorescence (SR-XRF). Naive and neural induced embryoid bodies derived from embryonic stem cells were irradiated with a spatial resolution of 20 {mu}m to make elemental maps and qualitative chemical analyses. We consistently detected metallic elements content raise on neural induced embryoid bodies, mimicking characteristic brain development. The use of SR-XRF reveals that human embryoid bodies exhibit self-organization at the atomic level, which is enhanced during neurogenesis triggered in vitro.

  3. Neonatal anthropometrics and body composition in obese children investigated by dual energy X-ray absorptiometry

    DEFF Research Database (Denmark)

    Lausten-Thomsen, Ulrik; Nielsen, Tenna Ruest Haarmark; Thagaard, Ida Näslund

    2014-01-01

    index (BFMI), and fat free mass index (FFMI) in obese children and the preceding in utero conditions expressed by birth weight, birth length, and birth weight for gestational age. The study cohort consisted of 776 obese Danish children (median age 11.6 years, range 3.6-17.9) with a mean Body Mass Index......UNLABELLED: Epidemiological and animal studies have suggested an effect of the intrauterine milieu upon the development of childhood obesity. This study investigates the relationship between body composition measured by dual energy X-ray absorptiometry expressed as body fat percent, body fat mass...... obesity treatment to be significantly correlated with both birth weight and birth weight for gestational age. CONCLUSION: These results indicate a prenatal influence upon childhood obesity. Although there are currently no sufficient data to suggest any recommendations to pregnant women, it is possible...

  4. Neural induced embryoid bodies present high levels of metals detected by x-ray microfluorescence

    Science.gov (United States)

    Stelling, Mariana P.; Cardoso, Simone C.; Paulsen, Bruna S.; Rehen, Stevens K.

    2012-05-01

    Molecular mechanisms driving neural differentiation in human embryonic stem cells are not completely elucidated, specially, the role of atomic elements within this process. In this work, we described the distribution of trace elements in those stem cells growing as embryoid bodies by using synchrotron radiation X-ray microfluorescence (SR-XRF). Naive and neural induced embryoid bodies derived from embryonic stem cells were irradiated with a spatial resolution of 20 μm to make elemental maps and qualitative chemical analyses. We consistently detected metallic elements content raise on neural induced embryoid bodies, mimicking characteristic brain development. The use of SR-XRF reveals that human embryoid bodies exhibit self-organization at the atomic level, which is enhanced during neurogenesis triggered in vitro.

  5. Determination of conversion factors between body doses and relevant radiation quantities for external X-ray and gamma irradiation

    International Nuclear Information System (INIS)

    Kramer, R.

    1979-02-01

    With particular consideration of ICRP-26 conversion factors between body doses and relevant radiation quantities for external X- and gamma radiation were assessed. Determination of these conversion factors included all areas of professional, medical, and environmental exposures. There was used a mathematical exposure model being essentially defined by application of a Monte Carlo photon transport calculation in a mathematical human phantom. Body doses were estimated for a reference man in relation to the relevant raditon quantities for different angles of incidence as a function of photon energy. The effective whole body dose defining the risk assessment of stochastic radiation effects was evaluated for the first time. There was also calculated the equivalent dose index which, with respect to radiation protection, is of special importance among the quantities characterizing radiation. The calculations indicated that for different irradiation directions in the energy range between 0.025 and 10 MeV the equivalent dose index gives a conservative estimation for the effective whole body dose. For X-ray diagnostic examinations in the body area the tissue surface dose may be regarded as an upper limit for body doses in the useful beam. The standard energy dose and the equivalent dose index are a conservative measure for important body doses in case of terrestrial radiation and fresh fall-out radiation from the ground. (orig./HP) [de

  6. Assessment of body composition by dual-energy X-ray absorptiometry, bioimpedance analysis and anthropometrics in children

    DEFF Research Database (Denmark)

    Tompuri, Tuomo T; Lakka, Timo A; Hakulinen, Mikko

    2015-01-01

    We compared InBody720 segmental multifrequency bioimpedance analysis (SMF-BIA) with Lunar Prodigy Advance dual-energy X-ray absorptiometry (DXA) in assessment of body composition among 178 predominantly prepubertal children. Segmental agreement analysis of body compartments was carried out...

  7. Measuring body composition in overweight individuals by dual energy x-ray absorptiometry

    International Nuclear Information System (INIS)

    Brownbill, Rhonda A; Ilich, Jasminka Z

    2005-01-01

    Dual energy x-ray absorptiometry (DXA) is widely used for body composition measurements in normal-weight and overweight/obese individuals. The limitations of bone densitometers have been frequently addressed. However, the possible errors in assessing body composition in overweight individuals due to incorrect positioning or limitations of DXA to accurately assess both bone mineral density and body composition in obese individuals have not received much attention and are the focus of this report. We discuss proper ways of measuring overweight individuals and point to some studies where that might not have been the case. It appears that currently, the most prudent approach to assess body composition of large individuals who cannot fit under the scanning area would be to estimate regional fat, namely the regions of thigh and/or abdomen. Additionally, using two-half body scans, although time consuming, may provide a relatively accurate measurement of total body fat, however, more studies using this technique are needed to validate it. Researchers using bone densitometers for body composition measurements need to have an understanding of its limitations in overweight individuals and address them appropriately when interpreting their results. Studies on accuracy and precision in measurements of both bone and soft tissue composition in overweight individuals using available densitometers are needed

  8. Pediatric body composition analysis with dual-energy X-ray absorptiometry

    Energy Technology Data Exchange (ETDEWEB)

    Helba, Maura; Binkovitz, Larry A. [Nationwide Children' s Hospital, Department of Radiology, Columbus, OH (United States)

    2009-07-15

    Pediatric applications of body composition analysis (BCA) have become of increased interest to pediatricians and other specialists. With the increasing prevalence of morbid obesity and with an increased awareness of anorexia nervosa, pediatric specialists are utilizing BCA data to help identify, treat, and prevent these conditions. Dual-energy X-ray absorptiometry (DXA) can be used to determine the fat mass (FM) and lean tissue mass (LTM), as well as bone mineral content (BMC). Among the readily available BCA techniques, DXA is the most widely used and it has the additional benefit of precisely quantifying regional FM and LTM. This review evaluates the strengths and limitations of DXA as a pediatric BCA method and considers the utilization of DXA to identify trends and variations in FM and LTM measurements in obese and anorexic children. (orig.)

  9. Pediatric body composition analysis with dual-energy X-ray absorptiometry

    International Nuclear Information System (INIS)

    Helba, Maura; Binkovitz, Larry A.

    2009-01-01

    Pediatric applications of body composition analysis (BCA) have become of increased interest to pediatricians and other specialists. With the increasing prevalence of morbid obesity and with an increased awareness of anorexia nervosa, pediatric specialists are utilizing BCA data to help identify, treat, and prevent these conditions. Dual-energy X-ray absorptiometry (DXA) can be used to determine the fat mass (FM) and lean tissue mass (LTM), as well as bone mineral content (BMC). Among the readily available BCA techniques, DXA is the most widely used and it has the additional benefit of precisely quantifying regional FM and LTM. This review evaluates the strengths and limitations of DXA as a pediatric BCA method and considers the utilization of DXA to identify trends and variations in FM and LTM measurements in obese and anorexic children. (orig.)

  10. Assessing Body Composition of Children and Adolescents Using Dual-Energy X-Ray Absorptiometry, Skinfolds, and Electrical Impedance

    Science.gov (United States)

    Mooney, Angela; Kelsey, Laurel; Fellingham, Gilbert W.; George, James D.; Hager, Ron L.; Myrer, J. William; Vehrs, Pat R.

    2011-01-01

    To determine the validity and reliability of percent body fat estimates in 177 boys and 154 girls between 12-17 years of age, percent body fat was assessed once using dual-energy X-ray absorptiometry and twice using the sum of two skinfolds and three bioelectrical impedance analysis devices. The assessments were repeated on 79 participants on a…

  11. A study of percentage body fat in children via dual energy X-ray absorptiometry (DEXA)

    International Nuclear Information System (INIS)

    Kawano, Shoji; Yagi, Shinichi; Fujino, Mitsuyoshi; Tanaka, Hiroyuki; Morita, Tetsuro; Fukunaga, Masao

    1994-01-01

    Percentage body fat was measured using dual energy X-ray absorptiometry (DEXA), bioelectrical impedance analysis (BIA) and skin fold calipers on 26 children (nine in obesity group, 12 in healthy group and 5 in steroid treated group). Mean percent body fat did not differ significantly between methods in the whole subjects as well as the healthy group and the steroid treated group. However, the mean percent body fat using skin fold caliper was higher for the obesity group than the other two. The measurements of all cases in the obesity group by DEXA were higher than those of BIA. There were high correlations among the percent body fat obtained by each technique. According to the analysis of mean regional percent fat, the percent fat of legs was the highest in the healthy and steroid treated group, while there was no regional difference in the obesity group. It should be possible to classify each case in the obesity group into upper segment and lower segment obesity by DEXA. (author)

  12. A study of percentage body fat in children via dual energy X-ray absorptiometry (DEXA)

    Energy Technology Data Exchange (ETDEWEB)

    Kawano, Shoji; Yagi, Shinichi; Fujino, Mitsuyoshi; Tanaka, Hiroyuki; Morita, Tetsuro; Fukunaga, Masao (Kawasaki Medical School, Kurashiki, Okayama (Japan))

    1994-05-01

    Percentage body fat was measured using dual energy X-ray absorptiometry (DEXA), bioelectrical impedance analysis (BIA) and skin fold calipers on 26 children (nine in obesity group, 12 in healthy group and 5 in steroid treated group). Mean percent body fat did not differ significantly between methods in the whole subjects as well as the healthy group and the steroid treated group. However, the mean percent body fat using skin fold caliper was higher for the obesity group than the other two. The measurements of all cases in the obesity group by DEXA were higher than those of BIA. There were high correlations among the percent body fat obtained by each technique. According to the analysis of mean regional percent fat, the percent fat of legs was the highest in the healthy and steroid treated group, while there was no regional difference in the obesity group. It should be possible to classify each case in the obesity group into upper segment and lower segment obesity by DEXA. (author).

  13. Dual-energy X-ray absorptiometry body composition in patients with secondary osteoporosis.

    Science.gov (United States)

    Messina, Carmelo; Monaco, Cristian Giuseppe; Ulivieri, Fabio Massimo; Sardanelli, Francesco; Sconfienza, Luca Maria

    2016-08-01

    Due to the tight relationship between bone and soft tissues, there has been an increased interest in body composition assessment in patients with secondary osteoporosis as well as other pathological conditions. Dual-energy X-ray absorptiometry (DXA) is primarily devoted to the evaluation of bone mineral status, but continuous scientific advances of body composition software made DXA a rapid and easily available technique to assess body composition in terms of fat mass and lean mass. As a result, the International Society for Clinical Densitometry (ISCD) recently developed Official Positions regarding the use of this technique for body composition analysis. According to ISCD paper, indications are mainly limited to three conditions: HIV patients treated with antiretroviral agents associated with a risk of lipoatrophy; obese patients undergoing treatment for high weight loss; patients with sarcopenia or muscle weakness. Nevertheless, there are several other interesting clinical applications that were not included in the ISCD position paper, such as body composition assessment in patients undergoing organ transplantation, pulmonary disease as well as all those chronic condition that may lead to malnutrition. In conclusion, DXA body composition offers new diagnostic and research possibilities for a variety of diseases; due to its high reproducibility, DXA has also the potential to monitor body composition changes with pharmacological, nutritional or physic therapeutic interventions. ISCD addressed and recommended a list of clinical condition, but the crescent availability of DXA scans and software improvements may open the use of DXA to other indication in the next future. This article provides an overview of DXA body composition indications in the management of secondary osteoporosis and other clinical indications in adults. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  14. Body-weight and chromosome aberrations induced by X-rays in somatic cells of Drosophila melanogaster

    International Nuclear Information System (INIS)

    Marco, A. de; Belloni, M.P.

    1976-01-01

    Body-weight has been shown to influence the final expression of genetic damage by X-rays in Drosophila melanogaster. If larvae of Drosophila were raised up to the third instar in media containing different amounts of the same nutrient and in different conditions of crowding a positive correlation was observed between body-weight and frequency of chromosome aberrations induced by a given dose of X-rays in the somatic cells of their nerve ganglia. This effect, present in both sexes, is most plausibly attributed to a different capacity of big and small larvae for repairing radiation damage. (orig.) [de

  15. Dual Energy X-Ray Absorptiometry Body Composition Reference Values from NHANES

    Science.gov (United States)

    Kelly, Thomas L.; Wilson, Kevin E.; Heymsfield, Steven B.

    2009-01-01

    In 2008 the National Center for Health Statistics released a dual energy x-ray absorptiometry (DXA) whole body dataset from the NHANES population-based sample acquired with modern fan beam scanners in 15 counties across the United States from 1999 through 2004. The NHANES dataset was partitioned by gender and ethnicity and DXA whole body measures of %fat, fat mass/height2, lean mass/height2, appendicular lean mass/height2, %fat trunk/%fat legs ratio, trunk/limb fat mass ratio of fat, bone mineral content (BMC) and bone mineral density (BMD) were analyzed to provide reference values for subjects 8 to 85 years old. DXA reference values for adults were normalized to age; reference values for children included total and sub-total whole body results and were normalized to age, height, or lean mass. We developed an obesity classification scheme by using estabbody mass index (BMI) classification thresholds and prevalences in young adults to generate matching classification thresholds for Fat Mass Index (FMI; fat mass/height2). These reference values should be helpful in the evaluation of a variety of adult and childhood abnormalities involving fat, lean, and bone, for establishing entry criteria into clinical trials, and for other medical, research, and epidemiological uses. PMID:19753111

  16. Dual energy X-Ray absorptiometry body composition reference values from NHANES.

    Directory of Open Access Journals (Sweden)

    Thomas L Kelly

    Full Text Available In 2008 the National Center for Health Statistics released a dual energy x-ray absorptiometry (DXA whole body dataset from the NHANES population-based sample acquired with modern fan beam scanners in 15 counties across the United States from 1999 through 2004. The NHANES dataset was partitioned by gender and ethnicity and DXA whole body measures of %fat, fat mass/height(2, lean mass/height(2, appendicular lean mass/height(2, %fat trunk/%fat legs ratio, trunk/limb fat mass ratio of fat, bone mineral content (BMC and bone mineral density (BMD were analyzed to provide reference values for subjects 8 to 85 years old. DXA reference values for adults were normalized to age; reference values for children included total and sub-total whole body results and were normalized to age, height, or lean mass. We developed an obesity classification scheme by using estabbody mass index (BMI classification thresholds and prevalences in young adults to generate matching classification thresholds for Fat Mass Index (FMI; fat mass/height(2. These reference values should be helpful in the evaluation of a variety of adult and childhood abnormalities involving fat, lean, and bone, for establishing entry criteria into clinical trials, and for other medical, research, and epidemiological uses.

  17. Manipulation of Muscle Creatine and Glycogen Changes Dual X-ray Absorptiometry Estimates of Body Composition.

    Science.gov (United States)

    Bone, Julia L; Ross, Megan L; Tomcik, Kristyen A; Jeacocke, Nikki A; Hopkins, Will G; Burke, Louise M

    2017-05-01

    Standardizing a dual x-ray absorptiometry (DXA) protocol is thought to provide a reliable measurement of body composition. We investigated the effects of manipulating muscle glycogen and creatine content independently and additively on DXA estimates of lean mass. Eighteen well-trained male cyclists undertook a parallel group application of creatine loading (n = 9) (20 g·d for 5 d loading; 3 g·d maintenance) or placebo (n = 9) with crossover application of glycogen loading (12 v 6 g·kg BM per day for 48 h) as part of a larger study involving a glycogen-depleting exercise protocol. Body composition, total body water, muscle glycogen and creatine content were assessed via DXA, bioelectrical impedance spectroscopy and standard biopsy techniques. Changes in the mean were assessed using the following effect-size scale: >0.2 small, >0.6, moderate, >1.2 large and compared with the threshold for the smallest worthwhile effect of the treatment. Glycogen loading, both with and without creatine loading, resulted in substantial increases in estimates of lean body mass (mean ± SD; 3.0% ± 0.7% and 2.0% ± 0.9%) and leg lean mass (3.1% ± 1.8% and 2.6% ± 1.0%) respectively. A substantial decrease in leg lean mass was observed after the glycogen depleting condition (-1.4% ± 1.6%). Total body water showed substantial increases after glycogen loading (2.3% ± 2.3%), creatine loading (1.4% ± 1.9%) and the combined treatment (2.3% ± 1.1%). Changes in muscle metabolites and water content alter DXA estimates of lean mass during periods in which minimal change in muscle protein mass is likely. This information needs to be considered in interpreting the results of DXA-derived estimates of body composition in athletes.

  18. Extremity x-ray

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003461.htm Extremity x-ray To use the sharing features on this page, ... in the body Risks There is low-level radiation exposure. X-rays are monitored and regulated to provide the ...

  19. Body composition by x-ray absorptiometry and bioelectrical impedance in female runners.

    Science.gov (United States)

    Pichard, C; Kyle, U G; Gremion, G; Gerbase, M; Slosman, D O

    1997-11-01

    Body composition interests athletes since athletic performance is influenced by and dependent on the proportion and total amount of fat-free mass (FFM) and fat mass. The use of bioelectrical impedance (BIA) has increased recently since portable instruments make the measurements easy to execute and relatively inexpensive. The purpose of this study was to test the degree of relationship between FFM and fat mass calculated in elite female runners with 12 different BIA formulas reported in the literature and measured by dual-energy x-ray absorptiometry (DXA). The present study shows that body composition by BIA is valid in female runners. Prediction equations used to calculate FFM and fat mass must be appropriate for this population subgroup and validated against other methods, such as DXA and hydrodensitometry. Those formulas that performed well in the controls gave poor results in the female runner and vice versa. The below average fat mass noted in female runners suggests that prediction equations for untrained women with average fat mass are inappropriate. The formula by RJL Systems-2 for women: FFM = 5.091 + 0.6483.height2/resistance + 0.1996.weight gave best predictions of FFM in female runners. Further research is necessary to validate BIA prediction formulas in other athletes.

  20. Body Composition Comparison: Bioelectric Impedance Analysis with Dual-Energy X-Ray Absorptiometry in Adult Athletes

    Science.gov (United States)

    Company, Joe; Ball, Stephen

    2010-01-01

    The primary purpose of this study was to investigate the accuracy of the DF50 (ImpediMed Ltd, Eight Mile Plains, Queensland, Australia) bioelectrical impedance analysis device using dual-energy x-ray absorptiometry as the criterion in two groups: endurance athletes and power athletes. The secondary purpose was to develop accurate body fat…

  1. Repeatability of Volume and Regional Body Composition Measurements of the Lower Limb Using Dual-energy X-ray Absorptiometry

    DEFF Research Database (Denmark)

    Gjorup, Caroline A; Zerahn, Bo; Juul, Sarah

    2017-01-01

    technique allowing multiple measurements of the lower limbs. This study investigated the repeatability of duplicate volume and regional body composition measurements of the lower limb using the GE Lunar Prodigy dual-energy X-ray absorptiometry (DXA) scanner Prodigy (GE Medical Systems, Madison, WI). Twenty...

  2. Foreign body detection in food materials using compton scattered x-rays

    Science.gov (United States)

    McFarlane, Nigel James Bruce

    This thesis investigated the application of X-ray Compton scattering to the problem of foreign body detection in food. The methods used were analytical modelling, simulation and experiment. A criterion was defined for detectability, and a model was developed for predicting the minimum time required for detection. The model was used to predict the smallest detectable cubes of air, glass, plastic and steel. Simulations and experiments were performed on voids and glass in polystyrene phantoms, water, coffee and muesli. Backscatter was used to detect bones in chicken meat. The effects of geometry and multiple scatter on contrast, signal-to-noise, and detection time were simulated. Compton scatter was compared with transmission, and the effect of inhomogeneity was modelled. Spectral shape was investigated as a means of foreign body detection. A signal-to-noise ratio of 7.4 was required for foreign body detection in food. A 0.46 cm cube of glass or a 1.19 cm cube of polystyrene were detectable in a 10 cm cube of water in one second. The minimum time to scan a whole sample varied as the 7th power of the foreign body size, and the 5th power of the sample size. Compton scatter inspection produced higher contrasts than transmission, but required longer measurement times because of the low number of photon counts. Compton scatter inspection of whole samples was very slow compared to production line speeds in the food industry. There was potential for Compton scatter in applications which did not require whole-sample scanning, such as surface inspection. There was also potential in the inspection of inhomogeneous samples. The multiple scatter fraction varied from 25% to 55% for 2 to 10 cm cubes of water, but did not have a large effect on the detection time. The spectral shape gave good contrasts and signal-to-noise ratios in the detection of chicken bones.

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... X-rays are a form of radiation like light or radio waves. X-rays pass through most objects, including the body. Once it is carefully aimed at the part of the body being examined, an x-ray machine produces a small ...

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the body. X-rays are the oldest and most frequently used form of medical imaging. A bone ... bones. top of page How should I prepare? Most bone x-rays require no special preparation. You ...

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... image on photographic film or a special detector. Different parts of the body absorb the x-rays ... process is repeated. Two or three images (from different angles) will typically be taken. An x-ray ...

  6. Apparatus for the examination of a living body by X-rays or γ-rays

    International Nuclear Information System (INIS)

    Hounsfield, G.N.

    1975-01-01

    The apparatus utilizes x-rays or gamma-rays for the representation of the absorption coefficients of a specimen of locations in a level area of the interior of a body with highly different tissues. It consists of the radiation source and a collector with collimator for a narrow bundle of rays. Collector and radiation source on the one hand, and the body on the other hand, are movable relative to each other into various angle- and lateral positions. For this purpose, the collector and the radiation source are attached to a scanning frame relative to a hollow space, with the hollow space serving as a receptable for the body. The scanning frame is controlled in such a way that a lateral scanning motion takes place for each of a succession of rotary steps. From the lateral scanning motion a group of output signals is led away which corresponds to the penetration or absorption of adjacent bundle of rays. Successive groups are led away in accordance with successive rotary steps. A matrix is at hand for the storage of the output signals which reproduces the sectional plane. The output signals are administered to the corresponding matrix elements associated with the scanning path. Drift effects or disturbances which, for instance, can result in ring patterns, are thereby prevented. Furthermore, a store for the storage of impedance factors for intersection areas of the bundles of rays which are associated with the matrix element can be provided. A distributor distributes fault signals, as a function of the valencies of the impedance factors, onto the matrix elements. (HP) [de

  7. Detecting meaningful body composition changes in athletes using dual-energy x-ray absorptiometry

    International Nuclear Information System (INIS)

    Colyer, Steffi L; Roberts, Simon P; Thompson, Dylan; Stokes, Keith A; Bilzon, James L J; Salo, Aki I T; Robinson, Jonathan B

    2016-01-01

    Dual-energy x-ray absorptiometry (DXA) imaging is considered to provide a valid and reliable estimation of body composition when stringent scanning protocols are adopted. However, applied practitioners are not always able to achieve this level of control and the subsequent impact on measurement precision is not always taken into account when evaluating longitudinal body composition changes. The primary aim of this study was to establish the reliability of DXA in an applied elite sport setting to investigate whether real body composition changes can be detected. Additionally, the performance implications of these changes during the training year were investigated. Forty-eight well-trained athletes (from four diverse sports) underwent two DXA scans using a ‘real-world’ approach (with limited pre-scan controls), typically within 48 h, to quantify typical error of measurement (TEM). Twenty-five athletes underwent further scans, before and after specific training and competition blocks. ‘True’ body composition changes were evaluated using 2  ×  TEM thresholds. Twelve bob skeleton athletes also performed countermovement jump and leg press tests at each time point. Many ‘true’ body composition changes were detected and coincided with the primary training emphases (e.g. lean mass gains during hypertrophy-based training). Clear relationships (r  ±  90% CI) were observed between performance changes (countermovement jump and leg press) and changes in lean mass (0.53  ±  0.26 and 0.35  ±  0.28, respectively) and fat mass (−0.44  ±  0.27 and  −0.37  ±  0.28, respectively). DXA was able to detect real body composition changes without the use of stringent scanning controls. Associations between changes in body composition and performance demonstrated the potential influence of these changes on strength and power indices. (paper)

  8. Comparison of diagnostic value of multidetector computed tomography and X-ray in the detection of body packing

    Energy Technology Data Exchange (ETDEWEB)

    Bulakci, Mesut, E-mail: mesutbulakci@yahoo.com [Department of Radiology, Haseki Training and Research Hospital, 34096 Aksaray, Istanbul (Turkey); Kalelioglu, Tuba, E-mail: tubakarsakarya@hotmail.com [Department of Radiology, Haseki Training and Research Hospital, 34096 Aksaray, Istanbul (Turkey); Bulakci, Betul Bozkurt, E-mail: dr.betulbozkurt@gmail.com [Department of Family Medicine, Istanbul University, Istanbul Faculty of Medicine, 34390 Capa, Istanbul (Turkey); Kiris, Adem, E-mail: ademkiris@hotmail.com [Department of Radiology, Haseki Training and Research Hospital, 34096 Aksaray, Istanbul (Turkey)

    2013-08-15

    Objective: Radiologists and other clinicians are facing an increasing number of illegal drug-related medical conditions. We aimed to draw attention to this growing global problem and to highlight some of the important points related to diagnosis and follow-up of body packing. We compare the diagnostic performance of unenhanced multidetector CT (MDCT) and abdomen X-ray for the detection of drug-filled packets. Materials and methods: Sixty-seven suspects, who underwent both CT and X-ray examinations, have been included in the study. All MDCT and X-ray images were independently and retrospectively reviewed by two observers with different degrees of experience in abdomen imaging. Fifty-two of them were identified as body packers finally. Interobserver agreement, sensitivity, specificity, positive and negative predictive value were calculated. Results: Two types of packets with different characteristics were identified in all body packers. Type 1 packets (solid-state drug) were found in 41 patients and type 2 packets (liquid cocaine) in 11 patients. All statistical analyses concern the detection of any packets. That is, the whole evaluation has been performed per patient. Sensitivity/specificity values of type 1 and type 2 packets for MDCT were 100–98%/100–100% and 100–100%/100–100%, respectively. Besides, sensitivity/specificity values of type 1 and type 2 packets for X-ray were 93–90%/100–91% and 64–45%/73–71%, respectively. In addition, interobserver agreements for detection of any packets were excellent (κ = 0.96) and good (κ = 0.75) for interpretation of MDCT and X-ray, respectively. Conclusion: Unenhanced MDCT is a fast, accurate and easily used diagnostic tool with high sensitivity and specificity for the exact diagnosis of body packing.

  9. Repetitive flash x-ray generator as an energy transfer source utilizing a compact-glass body diode

    Science.gov (United States)

    Shikoda, Arimitsu; Sato, Eiichi; Kimura, Shingo; Isobe, Hiroshi; Takahashi, Kei; Tamakawa, Yoshiharu; Yanagisawa, Toru

    1991-04-01

    The studies of a repetitive flash x-ray generator as an energy source achieved with a compact diode with a permeable anode are described. This source consisted of the following essential components: a constant negative high-voltage power supply of up to -100kV, a modified two-stage Marx pulser, a repetitive trigger device, and an x-ray tube. Two condensers in the pulser were charged from -50 to -80kV, and the output voltages (no-load) were less than -130kV. Since the capacity of each condenser was 85OpF, the total capacity during discharge was 425pF. The maximum tube voltage and the tube current were about 85kV and 0. 3kA, respectively. The xray pulse widths were less than l2Ons, and the repetitive rate was less than 40Hz. The time-integrated x-ray intensity was about 25pC/kg at 24mm per pulse with a charged voltage of 60kV and an anode-cathode (A-C) space of 9. 0mm, and the maximum size of the x-ray source was equivalent to an anode diameter of 27mm.

  10. Many-body effects on the x-ray spectra of metals

    International Nuclear Information System (INIS)

    Satpathy, S.S.

    1982-01-01

    The effects of band structure, of a solid surface, of temperature, and of disorder on the many-electron x-ray spectra of metals are evaluated in a change-of-mean-field approximation using a one-dimensional nearest-neighbor tight-binding model of a metal. The x-ray spectral shapes are determined by both the band structure and the final-state interactions. The effect of the band being non-free-electron-like is not felt at the x-ray threshold, but away from it such effects are noticeable. When the core hole is created at the surface, the spectra at the edge exhibit a Nozieres-de Dominicis-type singularity with the appropriate surface phase-shifts. At energies away from the edge, the one-particle effects are prominent with the x-ray emission and absorption spectra closely reflecting the local one-electron density of states. The recoil spectrum of a Fermi sea at a non-zero temperature has less asymmetry than the zero-temperature case. It was found that at ordinary temperatures the reduction of the asymmetry due to the thermal distribution of one-electron states is not very significant. Finally, using a one-dimensional Anderson model, the effect of lattice disorder on the x-ray absorption spectra is studied for the first time. There are two effects: (1) the strong infrared divergence peak is gradually quenched as disorder is increased, and (2) the threshold is broadened because the threshold energies for absorption at different sites in the crystal depend on the varying local lattice environment. It is proposed that the x-ray spectra may be useful as a tool for studying the degree of electron localization in disordered many-electron systems

  11. [Body composition by dual-energy x-ray absorptiometry in women with fibromyalgia].

    Science.gov (United States)

    Lobo, Márcia Maria Marques Teles; Paiva, Eduardo dos Santos; Andretta, Aline; Schieferdecker, Maria Eliana Madalozzo

    2014-01-01

    To assess body composition in women with fibromyalgia (FM) comparing to the reference value for healthy women. Cross-sectional observational analytical study, with 52 women selected with Fibromyalgia, according American College of Rheumatology (ACR, 1990) criteria. The patients were selected in Hospital de Clínicas da Universidade Federal do Paraná (HC-UFPR) and divided into two groups, 28 patients with a BMI (Body Mass Index) equal or higher (≥) than 25kg/m2 and 24 patients with BMI less or equal (≤) 24.99 kg/m2, subjected to physical examination for the count of tender points (TP) and completing the fibromyalgia impact questionnaire (FIQ). The assessment of body composition was performed by the Dual-Energy X-Ray Absorptiometry (DXA). The values of the fat mass percentage (MG %) found in the two groups were compared to the average percentage of MG by age and sex, described by Heward (2004). The mean age of the study groups was 47.8 ± 8.6 years, the FIQ score was 70.5 ± 18.6 and TP 16.2 ± 2.0. The mean BMI was 26.4 ± 4.1 kg/m2, and the amount of MG was 25.2 ± 7.8 kg and 39.5 ± 6.8%, and lean mass (LM) was 37 2 ± 3.7 kg and 60.4 ± 7.3%. In the group with BMI ≤ 25 kg/m2, the MG % was 33.8% (21.5 -42.4) and in the group with BMI ≥ 25 kg/m2 of the MG was 44.4% (37.6 -56.2). Both groups women with FM eutrophic as the overweight and obese group, presented higher reference MG% levels comparing with the standard levels for healthy women. Copyright © 2014 Elsevier Editora Ltda. All rights reserved.

  12. X-ray crystallography

    Science.gov (United States)

    2001-01-01

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

  13. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... body. Once it is carefully aimed at the part of the body being examined, an x-ray machine produces a small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different parts of the body absorb the x-rays in ...

  14. The study of dual energy X-ray absorptiometry on body composition components in obesity

    International Nuclear Information System (INIS)

    Huang Zhongkui; Chen Wei; Long Liling; Li Xiaoyang

    2009-01-01

    Objective: To study the correlation of the bone mineral density (BMD) and the body composition components of body mass index (BMI), FAT and LEAN in Chinese obesity. Methods: There were 150 cases in obesity group diagnosed by BMI, including 75 males [ median age 46 years, mean weight (89.64 ± 8.33) kg] and 75 females [median age 45 years, mean weight (77.23 ± 6.85) kg]. There were 150 persons with normal BMI in the control group, including 75 males [(median age 47 years, mean weight (62.34 ± 5.72) kg] and 75 females [ median age 45 years, mean weight (50.16 ± 5.06) kg]. The body height and weight of 300 persons in two groups were measured respectively and ,simultaneously calculated the BMI. These data and the body composition parameters measured by the dual energy X-ray absorptiometry (DEXA) in these two groups were compared and analyzed. The data obtained used two-sample t-test analysis, bi-variable correlation used Pearson linear correlation analysis and multi-variable correlation used multiple linear regression analysis. Results: FAT of arms, legs trunk and total body of male cases in obesity group was (2.90 ± 0.57), (7.48 ± 1.46), (15.67 ± 3.05), (30.92 ± 5.94) kg respectively, FAT% was (30.9 ± 5.1)%, (30.6 ± 5.8)%, (37.3 ± 4.7)%, (35.1 ± 4.4)% respectively, it was significantly higher than that in control group [FAT was (1.12 ± 0.64), (3.27 ± 1.22), (6.71 ± 3.29), (11.61 ± 5.16) kg respectively, FAT% was (15.4 ± 4.8)%, (16.5 ± 5.0)%, (21.8 ± 5.8)%, (18.6 ± 5.3)% respectively], P 2 respectively, it was significantly higher than that in control group [ LEAN was (22.89 ± 1.68), (48.89 ± 3.72) kg respectively, BMD was (0.89 ± 0.07), (1.15 ± 0.06) g/cm 2 respectively], P 2 respectively, and there were no statistical significance compared with those in control group [LEAN was (5.99 ± 0.72), (16.83 ± 1.67) kg respectively, BMD was (0.90 ± 0.08), (1.29 ± 0.09) g/cm 2 respectively]. FAT of arms, legs, trunk and total body of females in

  15. Beta-glucosidase activity of ER-bodies in Arabidopsis thaliana seedlings under clinorotation and after X-ray irradiation

    Science.gov (United States)

    Romanchuk, Svitlana

    Realization of long-term space flight requires the life support bioregenerative systems, an indispensable component of which are plants as a source of oxygen, water and food. Although it is well known now that plants adopt to spaceflight factors, in particular to microgravity, by changing some their patterns at the cellular, physiological, biochemical and molecular levels, many questions on cause and effect of these changes are still open. In addition, it is necessary to find the plant species which will be the most suited to the conditions in a space craft cabin. Plants of the family Brassicaceae are known to be resistant to a variety of abiotic stresses, including irradiation. Among them there are many cultivated plants with which we encounter every day: cabbage, radish, mustard, rapeseed, etc., and Arabidopsis thaliana - a convenient model object. The family Brassicaceae to be characterized by the presence of ER-bodies in plant cells, which are derivative of granular endoplasmic reticulum. Earlier, an enzyme beta-glucosidase (beta-D-glucoside glucohydrolase; EC 3.2.1.21) with an ER retention signal has been shown to accumulate selectively in such bodies in response to different unfavorable factors. Recently, we reported that formation of ER-bodies in A. thaliana seedling roots is sensitive to the clinorotation and X-ray irradiation, as their quantity and size in creased under the influence of these factors in comparison with control.begin{itemize} Therefore, we determined the beta-glucosidase activity in A. thaliana (line Columbia) seedlings grown in the stationary conditions and under clinorotation (a); and after X-ray irradiation (b): a) 3- and 7-day-old seedlings grown on a slow horizontal clinostat (2rpm); b) 3-day-old seedlings were treated with X-ray radiation dose of 0.5, 1.0, 2.0, 4.0, 6.0, 8.0, 10 and 12 Gray. For the first time, an increase in beta-glucosidase activity, which is the main component of the ER-bodies in A. thaliana seedlings, were found

  16. Accurate X-Ray Spectral Predictions: An Advanced Self-Consistent-Field Approach Inspired by Many-Body Perturbation Theory

    International Nuclear Information System (INIS)

    Liang, Yufeng; Vinson, John; Pemmaraju, Sri; Drisdell, Walter S.; Shirley, Eric L.; Prendergast, David

    2017-01-01

    Constrained-occupancy delta-self-consistent-field (ΔSCF) methods and many-body perturbation theories (MBPT) are two strategies for obtaining electronic excitations from first principles. Using the two distinct approaches, we study the O 1s core excitations that have become increasingly important for characterizing transition-metal oxides and understanding strong electronic correlation. The ΔSCF approach, in its current single-particle form, systematically underestimates the pre-edge intensity for chosen oxides, despite its success in weakly correlated systems. By contrast, the Bethe-Salpeter equation within MBPT predicts much better line shapes. This motivates one to reexamine the many-electron dynamics of x-ray excitations. We find that the single-particle ΔSCF approach can be rectified by explicitly calculating many-electron transition amplitudes, producing x-ray spectra in excellent agreement with experiments. This study paves the way to accurately predict x-ray near-edge spectral fingerprints for physics and materials science beyond the Bethe-Salpether equation.

  17. High resolution hard X-ray photoemission using synchrotron radiation as an essential tool for characterization of thin solid films

    International Nuclear Information System (INIS)

    Kim, J.J.; Ikenaga, E.; Kobata, M.; Takeuchi, A.; Awaji, M.; Makino, H.; Chen, P.P.; Yamamoto, A.; Matsuoka, T.; Miwa, D.; Nishino, Y.; Yamamoto, T.; Yao, T.; Kobayashi, K.

    2006-01-01

    Recently, we have shown that hard X-ray photoemission spectroscopy using undulator X-rays at SPring-8 is quite feasible with both high resolution and high throughput. Here we report an application of hard X-ray photoemission spectroscopy to the characterization of electronic and chemical states of thin solid films, for which conventional PES is not applicable. As a typical example, we focus on the problem of the scatter in the reported band-gap values for InN. We show that oxygen incorporation into the InN film strongly modifies the valence and plays a crucial role in the band gap problem. The present results demonstrate the powerful applicability of high resolution photoemission spectroscopy with hard X-rays from a synchrotron source

  18. Whole-body adipose tissue analysis: comparison of MRI, CT and dual energy X-ray absorptiometry

    DEFF Research Database (Denmark)

    Kullberg, J; Brandberg, J; Angelhed, J-E

    2009-01-01

    The aim of this study was to validate a recently proposed MRI-based T(1)-mapping method for analysis of whole-body adipose tissue (AT) using an established CT protocol as reference and to include results from dual energy X-ray absorptiometry (DEXA). 10 subjects, drawn from the Swedish Obese Subje......-processing of whole-body MRI data, allowing longitudinal whole-body studies that are also applicable for children and adolescents.......The aim of this study was to validate a recently proposed MRI-based T(1)-mapping method for analysis of whole-body adipose tissue (AT) using an established CT protocol as reference and to include results from dual energy X-ray absorptiometry (DEXA). 10 subjects, drawn from the Swedish Obese...... Subjects Sibling-pairs study, were examined using CT, MRI and DEXA. The CT analysis was based on 28 imaged slices. T(1) maps were calculated using contiguous MRI data from two different gradient echo sequences acquired using different flip angles. CT and MRI comparison was performed slice...

  19. Dose and induction to cancer risk evaluation associated to use of X ray body scanners by transmission at airports

    International Nuclear Information System (INIS)

    Correa, Samanda Cristine Arruda; Aquino, Josilto Oliveira de; Souza, Edmilson Monteiro de; Silva, Ademir Xavier da

    2011-01-01

    This paper uses the Monte Carlo MCNPX and the phantoms in male voxel and female voxel to evaluate the absorbed doses effective doses and the induction risk and the mortality due to cancer associated to exposures of individual submitted to X ray body scanners by transmission at various projections. The values of effective dose were calculated according to the recommended by the new ICRP 103 and the values of induction risks and mortality due to cancer were estimated through the document BEIR VII. (author)

  20. Diagnostic accuracy of full-body linear X-ray scanning in multiple trauma patients in comparison to computed tomography

    International Nuclear Information System (INIS)

    Joeres, A.P.W.; Heverhagen, J.T.; Bonel, H.; Exadaktylos, A.; Klink, T.; Wuerzburg Univ.

    2016-01-01

    The purpose of this study was to evaluate the diagnostic accuracy of full-body linear X-ray scanning (LS) in multiple trauma patients in comparison to 128-multislice computed tomography (MSCT). 106 multiple trauma patients (female: 33; male: 73) were retrospectively included in this study. All patients underwent LS of the whole body, including extremities, and MSCT covering the neck, thorax, abdomen, and pelvis. The diagnostic accuracy of LS for the detection of fractures of the truncal skeleton and pneumothoraces was evaluated in comparison to MSCT by two observers in consensus. Extremity fractures detected by LS were documented. The overall sensitivity of LS was 49.2%, the specificity was 93.3%, the positive predictive value was 91%, and the negative predictive value was 57.5%. The overall sensitivity for vertebral fractures was 16.7%, and the specificity was 100%. The sensitivity was 48.7% and the specificity 98.2% for all other fractures. Pneumothoraces were detected in 12 patients by CT, but not by LS.40 extremity fractures were detected by LS, of which 4 fractures were dislocated, and 2 were fully covered by MSCT. The diagnostic accuracy of LS is limited in the evaluation of acute trauma of the truncal skeleton. LS allows fast whole-body X-ray imaging, and may be valuable for detecting extremity fractures in trauma patients in addition to MSCT.

  1. Diagnostic accuracy of full-body linear X-ray scanning in multiple trauma patients in comparison to computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Joeres, A.P.W.; Heverhagen, J.T.; Bonel, H. [Inselspital - University Hospital Bern (Switzerland). Univ. Inst. of Diagnostic, Interventional and Pediatric Radiology; Exadaktylos, A. [Inselspital - University Hospital Bern (Switzerland). Dept. of Emergency Medicine; Klink, T. [Inselspital - University Hospital Bern (Switzerland). Univ. Inst. of Diagnostic, Interventional and Pediatric Radiology; Wuerzburg Univ. (Germany). Inst. of Diagnostic and Interventional Radiology

    2016-02-15

    The purpose of this study was to evaluate the diagnostic accuracy of full-body linear X-ray scanning (LS) in multiple trauma patients in comparison to 128-multislice computed tomography (MSCT). 106 multiple trauma patients (female: 33; male: 73) were retrospectively included in this study. All patients underwent LS of the whole body, including extremities, and MSCT covering the neck, thorax, abdomen, and pelvis. The diagnostic accuracy of LS for the detection of fractures of the truncal skeleton and pneumothoraces was evaluated in comparison to MSCT by two observers in consensus. Extremity fractures detected by LS were documented. The overall sensitivity of LS was 49.2%, the specificity was 93.3%, the positive predictive value was 91%, and the negative predictive value was 57.5%. The overall sensitivity for vertebral fractures was 16.7%, and the specificity was 100%. The sensitivity was 48.7% and the specificity 98.2% for all other fractures. Pneumothoraces were detected in 12 patients by CT, but not by LS.40 extremity fractures were detected by LS, of which 4 fractures were dislocated, and 2 were fully covered by MSCT. The diagnostic accuracy of LS is limited in the evaluation of acute trauma of the truncal skeleton. LS allows fast whole-body X-ray imaging, and may be valuable for detecting extremity fractures in trauma patients in addition to MSCT.

  2. Investigation of Essential Element Distribution in the Equine Metacarpophalangeal Joint using a Synchrotron Radiation Micro X-Ray Fluorescence Technique

    Science.gov (United States)

    Kaabar, Wejdan; Gundogdu, O.; Tzaphlidou, M.; Janousch, M.; Attenburrow, D.; Bradley, D. A.

    2008-05-01

    In articular cartilage, Ca, P, K and S are among some of the well known co-factors of the metalloproteinases enzymatic family, the latter playing a pivotal role in the growth and degeneration of the collagenous bone-cartilage interface of articulating joints. Current study forms part of a larger investigation concerning the distribution of these and other key elements in such media. For the purpose of evaluating these low atomic number elements (Z⩽20), use was made of the capabilities of the LUCIA Station, located at the synchrotron facility of the Paul Scherrer Institute (PSI). Using an incident radiation energy of 4.06 keV, a synchrotron radiation micro x-ray fluorescence (SR-μXRF) technique was applied in examining the distribution of the essential elements Ca, P, K and S in the bone-cartilage interface of both healthy and diseased (osteoarthritic) areas of an equine metacarpophalangeal joint. The SR-μXRF mappings and line profile patterns have revealed remarkable changes in both the pattern and absolute distributions of these elements, agreeing with the findings of others. The elemental presence shown in the individual area scans encompassing the lesion each reflect the visibly abraded outer surface of the cartilage and change in shape of the bone surface. One of the area scans for the bone-cartilage interface shows a marked change in both the pattern and absolute elemental presence for all three elements compared to that observed at two other scan sites. The observation of change in bone cartilage composition around the surface of the articulating joint is thought to be novel, the variation being almost certainly due to the differing weight-bearing role of the subchondral bone at each location.

  3. X-ray astronomy

    International Nuclear Information System (INIS)

    Giacconi, R.; Setti, G.

    1980-01-01

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

  4. Skull x-ray

    Science.gov (United States)

    X-ray - head; X-ray - skull; Skull radiography; Head x-ray ... There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most ...

  5. Neck x-ray

    Science.gov (United States)

    X-ray - neck; Cervical spine x-ray; Lateral neck x-ray ... There is low radiation exposure. X-rays are monitored so that the lowest amount of radiation is used to produce the image. Pregnant women and ...

  6. X-ray emission spectroscopy. X-ray fluorescence

    International Nuclear Information System (INIS)

    Despujols, J.

    1992-01-01

    Principles of X-ray emission spectrometry are first recalled, then wave-length dispersive and energy dispersive X-ray fluorescence spectrometer are described. They are essentially designed for qualitative and quantitative analysis of elements (Z>10). Sample preparation, calibration, corrections, interferences, accuracy are reviewed. Examples of use in different industries are given. (71 refs.)

  7. Evaluation of the impacts of the use of X-Ray body inspection technology in the Brazilian prison system

    International Nuclear Information System (INIS)

    Nante, T.A.; Lima, C.M. Araujo de; Lima, A.R.

    2017-01-01

    The crisis of the Brazilian Penitentiary System is visible with overcrowding, the appearance and growth of criminal factions, the lack of infrastructure of prisons, etc. This scenario led to the adoption of new technologies, such as the body inspection by X-rays, known as Body scanners. The technology is capable of detecting various illicit objects hidden under clothes or even in the pockets of individuals searched, following the recommendation of the National Council of Criminal and Penitentiary Policy, allowing a more effective search and the extinction of the intimate searches. The objective of this study is to evaluate the social impacts of the use of body inspection technology in prison units, including aspects of radiological protection related to operation and maintenance

  8. Total body bone mineral density changes in healthy Japanese children as assessed by dual energy X-ray absorptiometry

    Energy Technology Data Exchange (ETDEWEB)

    Osamura, Toshio; Ono, Kunihiko; Funaki, Hidenori; Fujita, Hiromi; Kidowaki, Takuro; Kiyosawa, Nobuyuki; Mizuta, Ryuzo (Kyoto Second Red Cross Hospital (Japan)); Hanayasu, Hajime; Yoshioka, Hiroshi

    1993-10-01

    For 68 healthy children (38 male and 30 female) ranging in age from 1 to 16 years, we measured the bone mineral density (BMD) of different regions (skull, upper extremities, ribs, thoracic spine, lumbar spine, pelvis and lower extremities) and the total body BMD using a dual energy X-ray absorptiometry (DEXA; QDR-1000/W, Hologic Co.). The total body BMD increased linearly with age for both sexes (male: r=0.9501, female: r=0.9715; p<0.0001). The increase was more prominent in boys compared to girls. There was also a positive correlation between the ratio of total body bone mineral content to lean body mass and age, although total body BMD showed a stronger correlation with age. Furthermore, the total body BMD correlated highly with body height and weight. There were positive correlations between the BMD of different regions and age. Specifically, the BMD of the lower extremities correlated strongly with age. In addition, the BMD of the skull increased at the highest rate. Considering convenience, accuracy and precision, measurement time, radiation exposure dose and the strong correlation with age, measurement of the total body BMD by DEXA is thought to be an effective method of quantifying bone mineral, useful in the evaluation of bone metabolism kinetics in children. (author).

  9. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... to produce pictures of any bone in the body. It is commonly used to diagnose fractured bones ... x-rays involves exposing a part of the body to a small dose of ionizing radiation to ...

  10. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different parts of the body absorb the x-rays in varying degrees. Dense ...

  11. Change in fat-free mass assessed by bioelectrical impedance, total body potassium and dual energy X-ray absorptiometry during prolonged weight loss

    DEFF Research Database (Denmark)

    Hendel, H W; Gotfredsen, A; Højgaard, L

    1996-01-01

    A total of 16 obese women (body mass index (BMI) 30-43 kg m(-2)) participated in a weight reduction study. Before and after a weight loss of 11.7 +/- 7.4 kg (mean +/- SD), body composition was assessed by dual energy X-ray absorptiometry (DXA), and total body potassium counting (TBK). These measu...

  12. Body composition in heavy smokers: comparison of segmental bioelectrical impedance analysis and dual-energy X-ray absorptiometry.

    Science.gov (United States)

    Rom, O; Reznick, A Z; Keidar, Z; Karkabi, K; Aizenbud, D

    2015-01-01

    Smokers tend to have lower body mass index, on one hand, and increased abdominal obesity, on the other hand. Also, low levels of lean mass (LM) and bone mineral content (BMC) were found among older smokers compared with non-smokers. This altered body composition and its consequences raise the need for simple and reliable methods for assessment of body composition in smokers. This study aimed to compare body composition assessment by segmental bioelectrical impedance analysis (sBIA) with the reference method, dual energy X-ray absorptiometry (DEXA). Body composition was measured by sBIA (Tanita BC-545) and DEXA (Hologic) in 49 heavy smokers (>15 cigarettes/day, mean age 43.8±12.0). The comparison included correlations and differences between measurements obtained using the two methods as well as the Blande-Altman analysis. Whole-body fat mass (FM) and LM measured by the two methods were found to be highly correlated (r>0.9, p0.9, p<0.001). However, sBIA significantly overestimated LM of the trunk and legs and underestimated the appendicular FM percentage. Verified by DEXA, sBIA provides reliable measures of whole-body LM, FM, and trunk FM in heavy smokers. A lesser degree of agreement was found for BMC, appendicular LM, and FM.

  13. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures that those parts of a patient's body not being imaged receive minimal radiation exposure. ...

  14. Modeling the shape and composition of the human body using dual energy X-ray absorptiometry images.

    Science.gov (United States)

    Shepherd, John A; Ng, Bennett K; Fan, Bo; Schwartz, Ann V; Cawthon, Peggy; Cummings, Steven R; Kritchevsky, Stephen; Nevitt, Michael; Santanasto, Adam; Cootes, Timothy F

    2017-01-01

    There is growing evidence that body shape and regional body composition are strong indicators of metabolic health. The purpose of this study was to develop statistical models that accurately describe holistic body shape, thickness, and leanness. We hypothesized that there are unique body shape features that are predictive of mortality beyond standard clinical measures. We developed algorithms to process whole-body dual-energy X-ray absorptiometry (DXA) scans into body thickness and leanness images. We performed statistical appearance modeling (SAM) and principal component analysis (PCA) to efficiently encode the variance of body shape, leanness, and thickness across sample of 400 older Americans from the Health ABC study. The sample included 200 cases and 200 controls based on 6-year mortality status, matched on sex, race and BMI. The final model contained 52 points outlining the torso, upper arms, thighs, and bony landmarks. Correlation analyses were performed on the PCA parameters to identify body shape features that vary across groups and with metabolic risk. Stepwise logistic regression was performed to identify sex and race, and predict mortality risk as a function of body shape parameters. These parameters are novel body composition features that uniquely identify body phenotypes of different groups and predict mortality risk. Three parameters from a SAM of body leanness and thickness accurately identified sex (training AUC = 0.99) and six accurately identified race (training AUC = 0.91) in the sample dataset. Three parameters from a SAM of only body thickness predicted mortality (training AUC = 0.66, validation AUC = 0.62). Further study is warranted to identify specific shape/composition features that predict other health outcomes.

  15. Validity of dual X-ray absorptiometry scanning for determination of body composition in IDDM patients

    DEFF Research Database (Denmark)

    Rosenfalck, A M; Almdal, Thomas Peter; Gotfredsen, A

    1995-01-01

    mass in IDDM patients and control subjects, as compared to other reference methods, i.e. total body potassium by 40K whole body counting (TBK), total body water by tritiated water (TBW), bioelectrical impedance analysis (BIA) and 24-h urinary creatinine excretion (Ucrea). A total of 13 healthy controls...

  16. Estimation of percentage body fat by dual-energy x-ray absorptiometry: evaluation by in vivo human elemental composition

    Science.gov (United States)

    Wang, ZiMian; Heymsfield, Steven B; Chen, Zhao; Zhu, Shankuan; Pierson, Richard N

    2010-01-01

    Dual-energy x-ray absorptiometry (DXA) is widely applied for estimating body fat. The percentage of body mass as fat (%fat) is predicted from a DXA-estimated RST value defined as the ratio of soft tissue attenuation at two photon energies (e.g., 40 keV and 70 keV). Theoretically, the RST concept depends on the mass of each major element in the human body. The DXA RST values, however, have never been fully evaluated by measured human elemental composition. The present investigation evaluated the DXA RST value by the total body mass of 11 major elements and the DXA %fat by the five-component (5C) model, respectively. Six elements (i.e. C, N, Na, P, Cl and Ca) were measured by in vivo neutron activation analysis, and potassium (i.e. K) by whole-body 40K counting in 27 healthy adults. Models were developed for predicting the total body mass of four additional elements (i.e. H, O, Mg and S). The elemental content of soft tissue, after correction for bone mineral elements, was used to predict the RST values. The DXA RST values were strongly associated with the RST values predicted from elemental content (r = 0.976, P composition, and the present study supports the underlying physical concept and accuracy of the DXA method for estimating %fat. PMID:20393230

  17. Effect of 25MV whole-body x-ray irradiation on endocrinous function of pancreas of rats

    International Nuclear Information System (INIS)

    Tsubota, Motoki; Dalimunthe, D.; Kawata, Ryoso; Ito, Chikako.

    1980-01-01

    The whole body of rats was exposed once to 800 rad of 25 MVX-ray which was estimated to be median lethal dose (LD-50), and the secretion mechanism of insulin and glucagon soon after the exposure was discussed. Trasient excessive blood glucose, mild relative decrease of the level of blood insulin, and increase of the level of glucagon were observed. Insulin release from the pancreas which was perfused with 20 mM arginine was accelerated 5 hours, 1 day, 2 days, and 3 days after the exposure and glucagon release were also accelerated 1, 2, and 3 days after the exposure. The acceleration of insulin and glucagon release was higher in rats exposed to radiation than that in controls. From the above-mentioned results, it was suggested that the endocrinous function of the pancreas of rats was not damages itself even by the exposure with LD-50 of x-ray. (Tsunoda, M.)

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

    Science.gov (United States)

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

    2014-12-01

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

  19. Fundamental Movement Skill Proficiency and Body Composition Measured by Dual Energy X-Ray Absorptiometry in Eight-Year-Old Children

    Science.gov (United States)

    Slotte, Sari; Sääkslahti, Arja; Metsämuuronen, Jari; Rintala, Pauli

    2015-01-01

    Objective: The main aim was to examine the association between fundamental movement skills (FMS) and objectively measured body composition using dual energy X-ray absorptiometry (DXA). Methods: A study of 304 eight-year-old children in Finland. FMS were assessed with the "Test of gross motor development," 2nd ed. Total body fat…

  20. Cosmic x ray physics

    Science.gov (United States)

    Mccammon, Dan; Cox, D. P.; Kraushaar, W. L.; Sanders, W. T.

    1991-01-01

    The annual progress report on Cosmic X Ray Physics for the period 1 Jan. to 31 Dec. 1990 is presented. Topics studied include: soft x ray background, new sounding rocket payload: x ray calorimeter, and theoretical studies.

  1. X-Ray

    Science.gov (United States)

    ... enema. What you can expect During the X-ray X-rays are performed at doctors' offices, dentists' offices, ... as those using a contrast medium. Your child's X-ray Restraints or other techniques may be used to ...

  2. Chest x-ray

    Science.gov (United States)

    Chest radiography; Serial chest x-ray; X-ray - chest ... There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most ...

  3. Abdominal x-ray

    Science.gov (United States)

    Abdominal film; X-ray - abdomen; Flat plate; KUB x-ray ... There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most ...

  4. Anthropometrics and body composition by dual energy X-ray in children of obese women

    DEFF Research Database (Denmark)

    Tanvig, Mette; Vinter, Christina A; Jørgensen, Jan S

    2014-01-01

    OBJECTIVE: In obese women, 1) to assess whether lower gestational weight gain (GWG) during pregnancy in the lifestyle intervention group of a randomized controlled trial (RCT) resulted in differences in offspring anthropometrics and body composition, and 2) to compare offspring outcomes to a refe......OBJECTIVE: In obese women, 1) to assess whether lower gestational weight gain (GWG) during pregnancy in the lifestyle intervention group of a randomized controlled trial (RCT) resulted in differences in offspring anthropometrics and body composition, and 2) to compare offspring outcomes......-score (intervention group 0.06 [-0.17; 0.29] vs. controls -0.18 [-0.43; 0.05]), in the percentage of overweight or obese children (10.9% vs. 6.7%), in other anthropometrics, or in body composition values by DEXA. Outcomes between children from the RCT and the reference group children were not significantly different....... CONCLUSIONS: The RCT with lifestyle intervention in obese pregnant women did not result in any detectable effect on offspring anthropometrics or body composition by DEXA at 2.8 years of age. This may reflect the limited difference in GWG between intervention and control groups. Offspring of obese mothers from...

  5. Quantification of mouse in vivo whole-body vibration amplitude from motion-blur using x-ray imaging

    International Nuclear Information System (INIS)

    Hu, Zhengyi; Yuan, Xunhua; Pollmann, Steven I; Nikolov, Hristo N; Holdsworth, David W; Welch, Ian

    2015-01-01

    Musculoskeletal effects of whole-body vibration on animals and humans have become an intensely studied topic recently, due to the potential of applying this method as a non-pharmacological therapy for strengthening bones. It is relatively easy to quantify the transmission of whole-body mechanical vibration through the human skeletal system using accelerometers. However, this is not the case for small-animal pre-clinical studies because currently available accelerometers have a large mass, relative to the mass of the animals, which causes the accelerometers themselves to affect the way vibration is transmitted. Additionally, live animals do not typically remain motionless for long periods, unless they are anesthetized, and they are required to maintain a static standing posture during these studies. These challenges provide the motivation for the development of a method to quantify vibrational transmission in small animals. We present a novel imaging technique to quantify whole-body vibration transmission in small animals using 280 μm diameter tungsten carbide beads implanted into the hind limbs of mice. Employing time-exposure digital x-ray imaging, vibrational amplitude is quantified based on the blurring of the implanted beads caused by the vibrational motion. Our in vivo results have shown this technique is capable of measuring vibration amplitudes as small as 0.1 mm, with precision as small as  ±10 μm, allowing us to distinguish differences in the transmitted vibration at different locations on the hindlimbs of mice. (paper)

  6. Quantification of mouse in vivo whole-body vibration amplitude from motion-blur using x-ray imaging

    Science.gov (United States)

    Hu, Zhengyi; Welch, Ian; Yuan, Xunhua; Pollmann, Steven I.; Nikolov, Hristo N.; Holdsworth, David W.

    2015-08-01

    Musculoskeletal effects of whole-body vibration on animals and humans have become an intensely studied topic recently, due to the potential of applying this method as a non-pharmacological therapy for strengthening bones. It is relatively easy to quantify the transmission of whole-body mechanical vibration through the human skeletal system using accelerometers. However, this is not the case for small-animal pre-clinical studies because currently available accelerometers have a large mass, relative to the mass of the animals, which causes the accelerometers themselves to affect the way vibration is transmitted. Additionally, live animals do not typically remain motionless for long periods, unless they are anesthetized, and they are required to maintain a static standing posture during these studies. These challenges provide the motivation for the development of a method to quantify vibrational transmission in small animals. We present a novel imaging technique to quantify whole-body vibration transmission in small animals using 280 μm diameter tungsten carbide beads implanted into the hind limbs of mice. Employing time-exposure digital x-ray imaging, vibrational amplitude is quantified based on the blurring of the implanted beads caused by the vibrational motion. Our in vivo results have shown this technique is capable of measuring vibration amplitudes as small as 0.1 mm, with precision as small as  ±10 μm, allowing us to distinguish differences in the transmitted vibration at different locations on the hindlimbs of mice.

  7. Body composition in male elite athletes, comparison of bioelectrical impedance spectroscopy with dual energy X-ray absorptiometry

    Directory of Open Access Journals (Sweden)

    Klingberg Sofia

    2008-01-01

    Full Text Available Abstract Background The aim of this study was to compare body composition results from bioelectrical spectroscopy (BIS with results from dual energy X-ray absorptiometry (DXA in a population of male elite athletes. Body composition was assessed using DXA (Lunar Prodigy, GE Lunar Corp., Madison, USA and BIS (Hydra 4200, Xitron Technologies Inc, San Diego, California, USA at the same occasion. Agreement between methods was assessed using paired t-tests and agreement-plots. Results Thirty-three male elite athletes (soccer and ice hockey were included in the study. The results showed that BIS underestimates the proportion of fat mass by 4.6% points in the ice hockey players. In soccer players the BIS resulted in a lower mean fat mass by 1.1% points. Agreement between the methods at the individual level was highly variable. Conclusion Body composition results assessed by BIS in elite athletes should be interpreted with caution, especially in individual subjects. BIS may present values of fat mass that is either higher or lower than fat mass assessed by DXA, independent of true fat content of the individual.

  8. X-ray imaging system

    International Nuclear Information System (INIS)

    Houston, J.M.

    1980-01-01

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

  9. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... bone in the body, including the hand, wrist, arm, elbow, shoulder, spine, pelvis, hip, thigh, knee, leg ( ... x-ray tube is connected to a flexible arm that is extended over the patient while an ...

  10. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... x-ray uses a very small dose of ionizing radiation to produce pictures of any bone in the ... of the body to a small dose of ionizing radiation to produce pictures of the inside of the ...

  11. X-ray astronomy

    International Nuclear Information System (INIS)

    Giacconi, R.; Gursky, H.

    1974-01-01

    This text contains ten chapters and three appendices. Following an introduction, chapters two through five deal with observational techniques, mechanisms for the production of x rays in a cosmic setting, the x-ray sky and solar x-ray emission. Chapters six through ten include compact x-ray sources, supernova remnants, the interstellar medium, extragalactic x-ray sources and the cosmic x-ray background. Interactions of x rays with matter, units and conversion factors and a catalog of x-ray sources comprise the three appendices. (U.S.)

  12. [Which alternative method to dual-energy X-ray absorptiometry for assessing body composition in overweight and obese adolescents?].

    Science.gov (United States)

    Lazzer, S; Boirie, Y; Meyer, M; Vermorel, M

    2005-07-01

    Professionals in charge of overweight and obese children and adolescents need a simple, reliable and precise method for assessing body composition. To compare body composition as assessed by dual-energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA) and the skinfold thickness (SFT) method in overweight and obese adolescents, and to establish and validate new predictive equations of body composition from BIA measurements using DXA as standard method. Body composition was assessed in 143 obese adolescents (Z-score = 3.2 +/- 1.4) aged 12 to 17 years by DXA, BIA (RJL System, Analycor and Analycor XF models) and SFT (Siri and Slaughter's equations). New prediction equations of fat mass (FM) as assessed by DXA were computed from BIA measurements in a calibration group, and validated in an homologous group of subjects. Results. - The Bland-Altman test showed that compared to DXA, BIA underestimated FM by 2.8 +/- 2.0 kg and 2.3 +/- 2.1 kg using the RJL System and Analycor impedancemeter, respectively (P Siri's equation underestimated FM by 4.0 +/- 2.9 kg (P < 0.001). The alternative to the DXA method to assess FM was BIA with new prediction equations including gender, body weight, height(2)/resistance and reactance. DXA, BIA and the SFT method were not directly interchangeable. The SFT method was inadequate to assess body composition in overweight and obese adolescents. BIA and new prediction equations could be an alternative to the DXA method in overweight and obese adolescents.

  13. Precision Error in Dual-Energy X-Ray Absorptiometry Body Composition Measurements in Elite Male Rugby League Players.

    Science.gov (United States)

    Barlow, Matthew J; Oldroyd, Brian; Smith, Debbie; Lees, Matthew J; Brightmore, Amy; Till, Kevin; Jones, Benjamin; Hind, Karen

    2015-01-01

    Body composition analysis using dual-energy X-ray absorptiometry (DXA) is becoming increasingly popular in both clinical and sports science settings. Obesity, characterized by high fat mass (FM), is associated with larger precision errors; however, precision error for athletic groups with high levels of lean mass (LM) are unclear. Total (TB) and regional (limbs and trunk) body composition were determined from 2 consecutive total body scans (GE Lunar iDXA) with re-positioning in 45 elite male rugby league players (age: 21.8 ± 5.4 yr; body mass index: 27.8 ± 2.5 kg m(-1)). The root mean squared standard deviation (percentage co-efficient of variation) were TB bone mineral content: 24g (1.7%), TB LM: 321 g (1.6%), and TB FM: 280 g (2.3%). Regional precision values were superior for measurements of bone mineral content: 4.7-16.3 g (1.7-2.1%) and LM: 137-402 g (2.0-2.4%), than for FM: 63-299 g (3.1-4.1%). Precision error of DXA body composition measurements in elite male rugby players is higher than those reported elsewhere for normal adult populations and similar to those reported in those who are obese. It is advised that caution is applied when interpreting longitudinal DXA-derived body composition measurements in male rugby players and population-specific least significant change should be adopted. Copyright © 2015 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  14. Whole body X-ray CT scanner SCT-3000T series

    International Nuclear Information System (INIS)

    Saida, Teruhiko; Takemura, Kunihiko; Suzuki, Satoru; Sato, Yukio; Kawamoto, Yasushi; Goto, Mitsuhiro; Mishina, Yukio

    1989-01-01

    The whole body CT scanner, SCT-3000T series which improve the patient through-put and the diagnostic capability, has been developed. In the SCT-3000T series CT scanners, the great reduction of the reconstruction time and the scan cycle time has been achieved by developing the special purpose hardwares for image reconstruction such as the fast front end processor, the intelligent buffer memory. In case of the SCT-3000TX routine conditions of operation, including 3.0 sec scan, table increment, image reconstruction and image filing, the scan cycle time is about 9 seconds which is the shortest value among the competitive models. Furthermore, the higher diagnostic capability has been provided with the system, by adopting the 1024 x 1024 display matrices, and by developing the diagnostic softwares such as 3-D display program, arbitrary curved plane MPR program, r-CBF measurement program and etc. (author)

  15. Personal experience with whole-body, low-dosage, digital X-ray scanning (LODOX-Statscan in trauma

    Directory of Open Access Journals (Sweden)

    Zimmermann Heinz

    2009-09-01

    Full Text Available Abstract Background Lodox-Statscan is a whole-body, skeletal and soft-tissue, low-dose X-ray scanner Anterior-posterior and lateral thoraco-abdominal studies are obtained in 3-5 minutes with only about one-third of the radiation required for conventional radiography. Since its approval by the Food and Drug Administration (FDA in the USA, several trauma centers have incorporated this technology into their Advanced Trauma Life Support protocols. This review provides a brief overview of the system, and describes the authors' own experience with the system. Methods We performed a PubMed search to retrieve all references with 'Lodox' and 'Stat-scan' used as search terms. We furthermore used the google search engine to identify existing alternatives. To the best of our knowledge, this is the only FDA-approved device of its kind currently used in trauma. Results and Conclusion The intention of our review has been to sensitize the readership that such alternative devices exist. The key message is that low dosage full body radiography may be an alternative to conventional resuscitation room radiography which is usually a prelude to CT scanning (ATLS algorithm. The combination of both is radiation intensive and therefore we consider any reduction of radiation a success. But only the future will show whether LS will survive in the face of low-dose radiation CT scanners and magnetic resonance imaging devices that may eventually completely replace conventional radiography.

  16. Precision of total and regional body fat estimates from dual-energy X-ray absorptiometer measurements.

    Science.gov (United States)

    Kaminsky, L A; Ozemek, C; Williams, K L; Byun, W

    2014-01-01

    To evaluate the precision of both total %fat and all the regional %fat measures acquired from both the Lunar Prodigy and Lunar iDXA software. Cross-sectional study. University-based research laboratory. The sample consisted of 300 individual test records from men and women who had volunteered to participate in dual-energy x-ray absorptiometer (DXA) technician precision training studies. Subjects ranged in age from 20-84 years and in body mass index from 15.7-52.0 kg.m-2. A total of 27 different technicians performed three total body scan measurements on 10-15 different subjects. The Lunar Prodigy and Lunar iDXA were used for 253 and 47 precision training evaluations, respectively. The regions of interest (ROI) were automatically determined by the enCORE software (autoROI) for total body, android, gynoid, trunk, legs, and arms regions and the region %fat data were used for analyses. The CV for total body %fat was 1.9% and 0.9% for the Prodigy and iDXA, respectively. CV's for %fat measures at regional sites ranged from 1.2-4.4% for the Prodigy measures and 0.9-2.4% for the iDXA measures. The ICC for both devices ranged from 0.990 to 0.999. Monitoring the status of body composition changes with age is gaining more clinical acceptance. Thus, it is important that practitioners use measures that are both precise and accurate. The findings from the current study add support that DXA measurements can be used with a high level of confidence for serial testing of patients.

  17. X-ray microtomography

    International Nuclear Information System (INIS)

    Dunsmuir, J.H.; Ferguson, S.R.; D'Amico, K.L.; Stokes, J.P.

    1991-01-01

    In this paper the authors describe the application of a new high-resolution X-ray tomographic microscope to the study of porous media. The microscope was designed to exploit the properties of a synchrotron X-ray source to perform three dimensional tomography on millimeter sized objects with micron resolution and has been used in materials science studies with both synchrotron and conventional and synchrotron sources will be compared. In this work the authors have applied the microscope to measure the three dimensional structure of fused bead packs and berea sandstones with micron resolution and have performed preliminary studies of flow in these media with the microscope operated in a digital subtraction radiography mode. Computer graphics techniques have been applied to the data to visually display the structure of the pore body system. Tomographic imaging after flow experiments should detect the structure of the oil-water interface in the pore network and this work is ongoing

  18. Study of food intake dynamics in rats following acute whole-body irradiation with X rays

    International Nuclear Information System (INIS)

    Smajda, B.; Ahlers, I.; Datelinka, I.

    1987-01-01

    The effects were studied of whole-body X-irradiation with sublethal (2.39 Gy) and medium lethal (5.74 Gy) doses on food intake by rats. The lower dose caused a temporary decrease in food intake, with a minimum of 63.3% of the control level on the 2nd day after irradiation. The decrease was statistically significant up to the 4th day after irradiation. No substantial changes were observed in the parameters of the circadian rhythm in food intake with the maximum on the 3rd day after irradiation, with only 8% of the initial value. The food intake was reduced until the 9th day after irradiation. The daily thythm of food intake was strongly disturbed during the first three days after irradiation, then restoring gradually and on the 9th day showing the original phasing and shape. The results obtained were in agreement with the assumed neural regulation mechanism of food intake and its circadian rhythm in the rat. (author). 5 figs., 12 refs

  19. Precision of dual energy X-ray absorptiometry for body composition measurements in cats

    International Nuclear Information System (INIS)

    Borges, N.C.; Vasconcellos, R.S.; Canola, J.C.; Carciofi, A.C.; Pereira, G.T.; Paula, F.J.A.

    2008-01-01

    A short-term precision error of the individual subject and the DEXA technique, such as the effect of the repositioning of the cat on the examination table, were established. Four neutered adult cats (BW=4342 g) and three females (BW=3459 g) were submitted to five repeated scans with and without repositioning between them. Precision was estimated from the mean of the five measurements and expressed by the individual coefficient of variation (CV). The precision error of the technique was estimated by the variance of scan pool (n=35) and expressed in CV for the technique (CVt). The degrees of freedom and confidence intervals were determined to avoid underestimation of precision errors. Bone mineral content (BMC), lean mass (LM), and fat mass (FM) averages were higher (P<0.05) when animals were repositioned. The CVt was significantly higher (P<0.05) for bone mineral density (BMD), LM, and FM when the animals were repositioned. For short-term precision measurements, the repositioning of the animal was important to establish the precision of the technique. The dual energy xray absorptiometry method provided precision for body composition measurements in adult cats. (author)

  20. Greater body mass independently predicts less radiographic progression on X-ray and MRI over 1-2 years

    DEFF Research Database (Denmark)

    Baker, Joshua F; Østergaard, Mikkel; George, Michael

    2014-01-01

    INTRODUCTION: Greater body mass index (BMI) has been associated with less radiographic progression in rheumatoid arthritis (RA). We evaluated the association between BMI and joint damage progression as measured by X-ray and MRI. METHODS: 1068 subjects with RA from two clinical trials of golimumab...

  1. Pathomorphological and pathogenetic studies of the radiation syndrome in calfs and heifers after whole-body irradiation with X-rays

    International Nuclear Information System (INIS)

    Johannsen, U.; Koch, E.; Mehlhorn, G.; Panndorf, H.

    1978-01-01

    27 calfs were exposed to whole-body X-ray doses of 170 R and 150 R, respectively. 14 animals which died between the 17th and 27th day after irradiation were examined. The most important pathomorphological findings were: hematopoietic disorders, hemorrhagic diatheses together with pneumonia, liver degeneration, damage to the intestine (only in animals irradiated with 170 R), and malnutrition

  2. Body composition and bone mineral mass in normal and obese female population using dual X-ray absorptiometry

    International Nuclear Information System (INIS)

    Massardo, T.; Gonzalez, P.; Coll, C.; Rodriguez, J.L.; Solis, I.; Oviedo, S.

    2002-01-01

    It has been observed that a greater percentage of body fat is associated with augmented bone mineral mass. Objective: The goal of this work was to assess the relationship between bone mineral density (BMD in g/cm 2 ) and content (BMC in g) and soft tissue components, fat and lean mass (in g) in whole body of adult female population in Chile. Method: We studied 185 volunteers, asymptomatic, excluding those using estrogens, regular medication, tobacco (>10 cigarettes/day), excessive alcohol intake or with prior oophorectomy. They were separated in 111 pre and 74 post menopausal and according to body mass index (BMI) they were 37 women > 30 kg/m 2 and 148 2 . A Lunar Dual X-Ray absorptiometer was used to determine whole BMD and BMC. Results: Post menopausal women were older and smaller [p:0.0001], with higher body mass index [p:0.0007] and with lower BMD and BMC and higher fat mass than the pre menopausal group; In the whole group, women with BMI ≥ 30 (obese) were compared with normal weight observing no difference in BMD. The fat mass incremented significantly with age. Obese women > 50 years presented greater BMC than the non-obese. The percentage of fat corresponded to 48% in the obese group and to 39% in the non-obese [p<0.0001]. Conclusion: Fat mass somehow protect bone mineral loss in older normal population, probably associated to multifactorial causes including extra ovaric estrogen production. Postmenopausal women presented lower mineral content than premenopausal, as it was expected

  3. Chest X-Ray

    Medline Plus

    Full Text Available ... about chest radiography also known as chest x-rays. Chest x-rays are the most commonly performed x-ray exams and use a very small dose of ... of the inside of the chest. A chest x-ray is used to evaluate the lungs, heart and ...

  4. X-ray sky

    International Nuclear Information System (INIS)

    Gruen, M.; Koubsky, P.

    1977-01-01

    The history is described of the discoveries of X-ray sources in the sky. The individual X-ray detectors are described in more detail, i.e., gas counters, scintillation detectors, semiconductor detectors, and the principles of X-ray spectrometry and of radiation collimation aimed at increased resolution are discussed. Currently, over 200 celestial X-ray sources are known. Some were identified as nebulae, in some pulsations were found or the source was identified as a binary star. X-ray bursts of novae were also observed. The X-ray radiation is briefly mentioned of spherical star clusters and of extragalactic X-ray sources. (Oy)

  5. Semiconductor X-ray detectors

    CERN Document Server

    Lowe, Barrie Glyn

    2014-01-01

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

  6. Assessment of Body Composition Using Dual Energy X-Ray Absorptiometry in Patients with Liver Cirrhosis: Comparison with Anthropometry

    Science.gov (United States)

    Jeong, Seong Han; Lee, Jeong A; Kim, Jin A; Lee, Mun Woo; Chae, Hee Bok; Choi, Won Jun; Shin, Hyoung Shik; Lee, Ki Hyeong; Youn, Sei Jin; Koong, Sung Soo; Park, Seon Mee

    1999-01-01

    Objectives The aim of this study was to evaluate changes of body composition in cirrhotic patients. Dual energy x-ray absorptiometry (DEXA) and anthropometry were used, and the values obtained were compared. Methods Mid-arm fat and muscle areas were calculated by anthropometry in 66 cirrhotic patients and 94 healthy controls. In 37 of the cirrhotic patients and 39 of the controls, fat mass, lean soft tissue mass and bone mineral contents were measured with DEXA. Results The number of cirrhotic patients with measured values below the fifth percentile of normal controls was 21 (31.8%) by mid-arm fat area, six (9.1%) by mid-arm muscle area, 15 (40.5%) by fat mass and 0 (0%) by lean soft tissue mass. The fat mass in cirrhotic patients was less than in controls, whereas lean soft tissue mass and bone mineral content were not different. Fat depletion was severe in Child-class C patients and with severe ascites. Mid-arm fat area and fat mass showed close correlation (r = 0.85, p<0.01), but mid-arm muscle area and lean soft tissue mass showed poor correlation (r = 0.32, p<0.05). Conclusion Cirrhotic patients showed lower fat component, with preserved lean soft tissue mass and bone mineral content. In clinical practice, the measurement of mid-arm fat area was useful for the assessment of fat mass. PMID:10461427

  7. Lean body mass assessment based on UV absorbance in spent dialysate and dual-energy x-ray absorptiometry.

    Science.gov (United States)

    Tomson, Ruth; Fridolin, Ivo; Luman, Merike

    2015-06-01

    The aim of the study was to explore the possibility of assessing lean body mass (LBM) based on UV absorbance measurements in spent dialysate. 9 patients on chronic three-times-a-week HD (4 female, 5 male, mean age 58.8 ± 8.6 years) were studied. Blood and spent dialysate samples were collected for 3 consecutive hemodialysis (HD) sessions from every patient. A double-beam spectrophotometer was used for the determination of UV absorbance in the collected spent dialysate samples. Dual-energy x-ray absorptiometry (DXA) scans were performed on an interdialytic day. LBM was calculated based on creatinine concentration in blood (LBMblood) and UV absorbance in spent dialysate (LBMa) and assessed by DXA (LBMDXA). Also, in vitro experiments were carried out to investigate the effect of tissue hydration on DXA measurements. Although LBMa was slightly lower compared to LBMblood, the estimates based on UV absorbance in spent dialysate presented greater accuracy and precision compared to LBMDXA. The significant difference between LBMblood and LBMDXA was with high probability caused by the altered tissue hydration of HD patents. In summary, the results show that it is possible to asses LBM based on UV absorbance in spent dialysate.

  8. Measuring body composition in dogs using multifrequency bioelectrical impedance analysis and dual energy X-ray absorptiometry.

    Science.gov (United States)

    Rae, L S; Vankan, D M; Rand, J S; Flickinger, E A; Ward, L C

    2016-06-01

    Thirty-five healthy, neutered, mixed breed dogs were used to determine the ability of multifrequency bioelectrical impedance analysis (MFBIA) to predict accurately fat-free mass (FFM) in dogs using dual energy X-ray absorptiometry (DXA)-measured FFM as reference. A second aim was to compare MFBIA predictions with morphometric predictions. MFBIA-based predictors provided an accurate measure of FFM, within 1.5% when compared to DXA-derived FFM, in normal weight dogs. FFM estimates were most highly correlated with DXA-measured FFM when the prediction equation included resistance quotient, bodyweight, and body condition score. At the population level, the inclusion of impedance as a predictor variable did not add substantially to the predictive power achieved with morphometric variables alone; in individual dogs, impedance predictors were more valuable than morphometric predictors. These results indicate that, following further validation, MFBIA could provide a useful tool in clinical practice to objectively measure FFM in canine patients and help improve compliance with prevention and treatment programs for obesity in dogs. Copyright © 2016. Published by Elsevier Ltd.

  9. Assessment of EchoMRI-AH versus dual-energy X-ray absorptiometry to measure human body composition.

    Science.gov (United States)

    Galgani, J E; Smith, S R; Ravussin, E

    2011-09-01

    The sensitivity to detect small changes in body composition (fat mass and fat-free mass) largely depends on the precision of the instrument. We compared EchoMRI-AH and dual-energy X-ray absorptiometry (DXA) (Hologic QDR-4500A) for estimating fat mass in 301 volunteers. Body composition was evaluated in 136 males and 165 females with a large range of body mass index (BMI) (19-49 kg m(-2)) and age (19-91 years old) using DXA and EchoMRI-AH. In a subsample of 13 lean (BMI=19-25 kg m(-2)) and 21 overweight/obese (BMI>25 kg m(-2)) individuals, within-subject precision was evaluated from repeated measurements taken within 1 h (n=3) and 1 week apart (mean of three measurements taken on each day). Using Bland-Altman analysis, we compared the mean of the fat mass measurements versus the difference in fat mass measured by both instruments. We found that EchoMRI-AH quantified larger amount of fat versus DXA in non-obese (BMI<30 kg m(-2) (1.1 kg, 95% confidence interval (CI(95)):-3.7 to 6.0)) and obese (BMI ≥ 30 kg m(-2) (4.2 kg, CI(95):-1.4 to 9.8)) participants. Within-subject precision (coefficient of variation, %) in fat mass measured within 1 h was remarkably better when measured by EchoMRI-AH than DXA (<0.5 versus <1.5%, respectively; P<0.001). However, 1-week apart within-subject variability showed similar values for both instruments (<2.2%; P=0.15). EchoMRI-AH yielded greater fat mass values when compared with DXA (Hologic QDR-4500A), particularly in fatter subjects. EchoMRI-AH and DXA showed similar 1-week apart precision when fat mass was measured both in lean and overweight/obese individuals.

  10. X-ray Ordinance

    International Nuclear Information System (INIS)

    Kramer, R.; Zerlett, G.

    1983-01-01

    This commentary, presented as volume 2 of the Deutsches Strahlenschutzrecht (German legislation on radiation protection) deals with the legal provisions of the ordinance on the protection against harmful effects of X-radiation (X-ray Ordinance - RoeV), of March 1, 1973 (announced in BGBl.I, page 173), as amended by the ordinance on the protection against harmful effects of ionizing radiation, of October 13, 1976 (announced in BGBl. I, page 2905). Thus volume 2 completes the task started with volume 1, namely to present a comprehensive view and account of the body of laws governing radiation protection, a task which was thought useful as developments in the FRG led to regulations being split up into the X-ray Ordinance, and the Radiation Protection Ordinance. In order to present a well-balanced commentary on the X-ray Ordinance, it was necessary to discuss the provisions both from the legal and the medical point of view. This edition takes into account the Fourth Public Notice of the BMA (Fed. Min. of Labour and Social Affairs) concerning the implementation of the X-ray Ordinance of January 4, 1982, as well as court decisions and literature published in this field, until September 1982. In addition, the judgment of the Federal Constitutional Court, dated October 19, 1982, concerning the voidness of the law on government liability, and two decisions by the Federal High Court, dated November 23, 1982, concerning the right to have insight into medical reports - of great significance in practice - have been considered. This commentary therefore is up to date with current developments. (orig.) [de

  11. X-ray tube target

    International Nuclear Information System (INIS)

    Weber, R.G.

    1980-01-01

    A target with an improved heat emissive surface for use in a rotating anode type x-ray tube is described. The target consists of a body having a first surface portion made of x-ray emissive material and a second surface portion made of a heat emissive material comprising at least one of hafnium boride, hafnium oxide, hafnium nitride, hafnium silicide, and hafnium aluminide. (U.K.)

  12. Estimation of percentage body fat by dual-energy x-ray absorptiometry: evaluation by in vivo human elemental composition

    Energy Technology Data Exchange (ETDEWEB)

    Wang Zimian; Pierson, Richard N [Obesity Research Center, St Luke' s-Roosevelt Hospital, Columbia University, College of Physicians and Surgeons, New York, NY (United States); Heymsfield, Steven B [Clinical Research, Metabolism, Merck Research Laboratories, Rahway, NJ (United States); Chen Zhao [Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ (United States); Zhu Shankuan, E-mail: zw28@columbia.ed [Obesity and Body Composition Research Center, Zhejiang University, School of Public Health, Hangzhou (China)

    2010-05-07

    Dual-energy x-ray absorptiometry (DXA) is widely applied for estimating body fat. The percentage of body mass as fat (%fat) is predicted from a DXA-estimated R{sub ST} value defined as the ratio of soft tissue attenuation at two photon energies (e.g., 40 keV and 70 keV). Theoretically, the R{sub ST} concept depends on the mass of each major element in the human body. The DXA R{sub ST} values, however, have never been fully evaluated by measured human elemental composition. The present investigation evaluated the DXA R{sub ST} value by the total body mass of 11 major elements and the DXA %fat by the five-component (5C) model, respectively. Six elements (i.e. C, N, Na, P, Cl and Ca) were measured by in vivo neutron activation analysis, and potassium (i.e. K) by whole-body {sup 40}K counting in 27 healthy adults. Models were developed for predicting the total body mass of four additional elements (i.e. H, O, Mg and S). The elemental content of soft tissue, after correction for bone mineral elements, was used to predict the R{sub ST} values. The DXA R{sub ST} values were strongly associated with the R{sub ST} values predicted from elemental content (r = 0.976, P < 0.001), although there was a tendency for the elemental-predicted R{sub ST} to systematically exceed the DXA-measured R{sub ST} (mean {+-} SD, 1.389 {+-} 0.024 versus 1.341 {+-} 0.024). DXA-estimated %fat was strongly associated with 5C %fat (24.4 {+-} 12.0% versus 24.9 {+-} 11.1%, r = 0.983, P < 0.001). DXA R{sub ST} is evaluated by in vivo elemental composition, and the present study supports the underlying physical concept and accuracy of the DXA method for estimating %fat.

  13. Skinfold thicknesses method to analyse body fat in hemodialysis patients: comparison with dual energy x-ray absorptiometry

    Directory of Open Access Journals (Sweden)

    Viviane O Leal

    2012-06-01

    Full Text Available Nutritional status is a major determinant of the outcome of hemodialysis (HD patients. While protein wasting is associated with morbidity and mortality, high fat mass and central adiposity is also observed in HD population and, related to metabolic disorders. Therefore, body composition assessment is a key point to provide adequate nutritional care to these patients. In this way, practical and reliable indicators of body composition are needed for clinical purposes. Thus, the objective of this study was to evaluate the use of anthropometry as an alternative to dual energy X-ray absorptiometry (DXA, considered the reference method to evaluate body fat in HD patients. Thirty-nine HD patients (52.7±11.3 years, 24 men, BMI, 23.7±4.0 kg/m2, urea clearance (Kt/Vsp of 1.47±0.22 and 64.1±46.1 months on HD were studied. Percentage of body fat (%BF was performed by DXA scans (Prodigy Advanc Plus, Lunar Corp, Madison, WI, USA and anthropometry (biceps, triceps, subscapular and suprailiac skinfold thicknesses after a HD session. Body density was calculated using the formula of Durnin and Womersley (1974 and the %BF was calculated by Siri´s equation (Siri, 1961. The reference values for %BF were considered (Lohman et al., 1991. The mean of %BF assessed by anthopometry and DXA was 25.2±6.9% and 26.8±8.3% for men and 32.8±6.3% and 31.5±8.7% for women, respectively. The most of HD patients presented high %BF (≥25% for men and ≥32% for women: 59.0% by anthropometry and 56.4% by DXA. The paired analysis showed that the %BF assessment was not different when evaluated by anthropometry or DXA methods (p=0.6. The kappa coefficient between DXA and anthropometry was 0.42 (p<0.0001, which is considered as good correlation between two methods. In conclusion, the simple method of skinfold thicknesses is reliable to assess body fat in HD patients when compared to DXA.

  14. Dual energy X-ray absorptiometry positioning protocols in assessing body composition: A systematic review of the literature.

    Science.gov (United States)

    Shiel, Flinn; Persson, Carl; Furness, James; Simas, Vini; Pope, Rodney; Climstein, Mike; Hing, Wayne; Schram, Ben

    2018-03-16

    To systematically identify and assess methods and protocols used to reduce technical and biological errors in published studies that have investigated reliability of dual energy X-ray absorptiometry (DXA) for assessing body composition. Systematic review. Systematic searches of five databases were used to identify studies of DXA reliability. Two independent reviewers used a modified critical appraisal tool to assess their methodological quality. Data was extracted and synthesised using a level of evidence approach. Further analysis was then undertaken of methods used to decrease DXA errors (technical and biological) and so enhance DXA reliability. Twelve studies met eligibility criteria. Four of the articles were deemed high quality. Quality articles considered biological and technical errors when preparing participants for DXA scanning. The Nana positioning protocol was assessed to have a strong level of evidence. The studies providing this evidence indicated very high test-retest reliability (ICC 0.90-1.00 or less than 1% change in mean) of the Nana positioning protocol. The National Health and Nutrition Examination Survey (NHANES) positioning protocol was deemed to have a moderate level of evidence due to lack of high quality studies. However, the available studies found the NHANES positioning protocol had very high test-retest reliability. Evidence is limited and reported reliability has varied in papers where no specific positioning protocol was used or reported. Due to the strong level of evidence of excellent test-retest reliability that supports use of the Nana positioning protocol, it is recommended as the first choice for clinicians when using DXA to assess body composition. Copyright © 2018. Published by Elsevier Ltd.

  15. Predictive Validity of the Body Adiposity Index in Overweight and Obese Adults Using Dual-Energy X-ray Absorptiometry

    Directory of Open Access Journals (Sweden)

    Robinson Ramírez-Vélez

    2016-11-01

    Full Text Available The body adiposity index (BAI is a recent anthropometric measure proven to be valid in predicting body fat percentage (BF% in some populations. However, the results have been inconsistent across populations. This study was designed to verify the validity of BAI in predicting BF% in a sample of overweight/obese adults, using dual-energy X-ray absorptiometry (DEXA as the reference method. A cross-sectional study was conducted in 48 participants (54% women, mean age 41.0 ± 7.3 years old. DEXA was used as the “gold standard” to determine BF%. Pearson’s correlation coefficient was used to evaluate the association between BAI and BF%, as assessed by DEXA. A paired sample t-test was used to test differences in mean BF% obtained with BAI and DEXA methods. To evaluate the concordance between BF% as measured by DEXA and as estimated by BAI, we used Lin’s concordance correlation coefficient and Bland–Altman agreement analysis. The correlation between BF% obtained by DEXA and that estimated by BAI was r = 0.844, p < 0.001. Paired t-test showed a significant mean difference in BF% between methods (BAI = 33.3 ± 6.2 vs. DEXA 39.0 ± 6.1; p < 0.001. The bias of the BAI was −6.0 ± 3.0 BF% (95% CI = −12.0 to 1.0, indicating that the BAI method significantly underestimated the BF% compared to the reference method. Lin’s concordance correlation coefficient was considered stronger (ρc = 0.923, 95% CI = 0.862 to 0.957. In obese adults, BAI presented low agreement with BF% measured by DEXA; therefore, BAI is not recommended for BF% prediction in this overweight/obese sample studied.

  16. Predictive Validity of the Body Adiposity Index in Overweight and Obese Adults Using Dual-Energy X-ray Absorptiometry

    Science.gov (United States)

    Ramírez-Vélez, Robinson; Correa-Bautista, Jorge Enrique; González-Ruíz, Katherine; Vivas, Andrés; García-Hermoso, Antonio; Triana-Reina, Hector Reynaldo

    2016-01-01

    The body adiposity index (BAI) is a recent anthropometric measure proven to be valid in predicting body fat percentage (BF%) in some populations. However, the results have been inconsistent across populations. This study was designed to verify the validity of BAI in predicting BF% in a sample of overweight/obese adults, using dual-energy X-ray absorptiometry (DEXA) as the reference method. A cross-sectional study was conducted in 48 participants (54% women, mean age 41.0 ± 7.3 years old). DEXA was used as the “gold standard” to determine BF%. Pearson’s correlation coefficient was used to evaluate the association between BAI and BF%, as assessed by DEXA. A paired sample t-test was used to test differences in mean BF% obtained with BAI and DEXA methods. To evaluate the concordance between BF% as measured by DEXA and as estimated by BAI, we used Lin’s concordance correlation coefficient and Bland–Altman agreement analysis. The correlation between BF% obtained by DEXA and that estimated by BAI was r = 0.844, p < 0.001. Paired t-test showed a significant mean difference in BF% between methods (BAI = 33.3 ± 6.2 vs. DEXA 39.0 ± 6.1; p < 0.001). The bias of the BAI was −6.0 ± 3.0 BF% (95% CI = −12.0 to 1.0), indicating that the BAI method significantly underestimated the BF% compared to the reference method. Lin’s concordance correlation coefficient was considered stronger (ρc = 0.923, 95% CI = 0.862 to 0.957). In obese adults, BAI presented low agreement with BF% measured by DEXA; therefore, BAI is not recommended for BF% prediction in this overweight/obese sample studied. PMID:27916871

  17. Reproducibility of pediatric whole body bone and body composition measures by dual-energy X-ray absorptiometry using the GE Lunar Prodigy.

    Science.gov (United States)

    Margulies, Lauren; Horlick, Mary; Thornton, John C; Wang, Jack; Ioannidou, Elli; Heymsfield, Steven B

    2005-01-01

    The use of dual-energy X-ray absorptiometry (DXA) in pediatrics is increasing. It is safe, readily available, and easily performed, but there is little information on reproducibility. The aim of this study is to evaluate the reproducibility of whole body DXA scans in children. Total and regional bone mineral density, bone mineral content, nonbone, lean fat mass, and percent fat were measured twice by whole body DXA (GE Lunar Prodigy) in 49 subjects (5 to 17 yr). Within each subject, between subjects, and reading standard deviations for each body component were evaluated as well as intraclass correlations (IC) and coefficients of variation (CV). Total body measurements had better IC and CV than regional results from the whole body scan, with legs and arms better than trunk and spine. IC values were >or=0.989 for total body, >or=0.976 for legs and arms, and >or=0.875 for trunk and spine. CV values ranged 0.18 to 1.97% for total body, and 0.96 to 6.91% for regional measures. These values confirm that body composition and bone mass by DXA are highly reproducible among pediatric subjects. The results of this study can be used by clinicians and researchers for interpretation of longitudinal observations and for power calculations.

  18. Development of an ionization chamber based high sensitivity detector for the measurement of radiation dose from X-ray whole body scanners

    International Nuclear Information System (INIS)

    Singh, Sunil K.; Tripathi, S.M.; LijiShaiju; Sathian, V.; Kulkarni, M.S.

    2016-01-01

    Using walk through metal detectors and undergoing frisking for personals at airports, seaports, railway stations and other sensitive places no longer meets proper security requirements. Now a days use of plastic explosives, drug trafficking or illegal carriage of dangerous items concealed under cloths or body cavities has increased many folds which in many cases is not possible to detect by conventional methods. One of the systems which are capable to overcome the above mentioned difficulties is the use of X-ray based whole body scanners, either transmission type or backscatter type, depending upon the nature of requirement. While using these whole body scanners the person being scanned possesses a radiation risk whose safety aspects can be monitored by following international standards (recommending certain dose limits). In order to check the compliance of these dose limits, the dose per scan received by the person (from these whole body scanners) needs to be measured. A very high sensitive ionization chamber has been designed and fabricated for measuring these extremely low X- ray fields ( few μR) produced by a scanning X-ray beam over a large area. A methodology has been developed to measure exposure per scan using large volume ionization chambers. This value of exposure was used to calculate whole body dose as per the recommendations of ANSI standard for its compliance

  19. X-ray apparatus

    International Nuclear Information System (INIS)

    Sell, L.J.

    1981-01-01

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

  20. X-ray - skeleton

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003381.htm X-ray - skeleton To use the sharing features on this ... Degenerative bone conditions Osteomyelitis Risks There is low radiation exposure. X-rays machines are set to provide the smallest ...

  1. Dental x-rays

    Science.gov (United States)

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

  2. Chest X-Ray

    Medline Plus

    Full Text Available ... some concerns about chest x-rays. However, it’s important to consider the likelihood of benefit to your health. While a chest x-ray use a ... posted: How to Obtain and Share ...

  3. Pathomorphological studies of the radiation syndrome in sheep after whole-body irradiation with X-rays

    International Nuclear Information System (INIS)

    Johannsen, U.; Mehlhorn, G.; Koch, F.; Panndorf, H.

    1978-01-01

    Eight one-year-old Merino mutton sheep were irradiated with X-ray doses of 380 R. Five of the animals died between the 16th and 25th day after irradiation and were examined. In organs and tissues a great diversity of pathological changes was observed as for instance hematopoietic disorders, septic processes, hemorrhagic diatheses, and partial epilation

  4. Chest X-Ray

    Medline Plus

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

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different ... This ensures that those parts of a patient's body not being imaged receive minimal radiation ... x-ray images are among the clearest, most detailed views of ...

  6. Flash X-ray

    International Nuclear Information System (INIS)

    Sato, Eiichi

    2003-01-01

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

  7. Prediction of Android and Gynoid Body Adiposity via a Three-dimensional Stereovision Body Imaging System and Dual-Energy X-ray Absorptiometry.

    Science.gov (United States)

    Lee, Jane J; Freeland-Graves, Jeanne H; Pepper, M Reese; Stanforth, Philip R; Xu, Bugao

    2015-01-01

    Current methods for measuring regional body fat are expensive and inconvenient compared to the relative cost-effectiveness and ease of use of a stereovision body imaging (SBI) system. The primary goal of this research is to develop prediction models for android and gynoid fat by body measurements assessed via SBI and dual-energy x-ray absorptiometry (DXA). Subsequently, mathematical equations for prediction of total and regional (trunk, leg) body adiposity were established via parameters measured by SBI and DXA. A total of 121 participants were randomly assigned into primary and cross-validation groups. Body measurements were obtained via traditional anthropometrics, SBI, and DXA. Multiple regression analysis was conducted to develop mathematical equations by demographics and SBI assessed body measurements as independent variables and body adiposity (fat mass and percentage fat) as dependent variables. The validity of the prediction models was evaluated by a split sample method and Bland-Altman analysis. The R(2) of the prediction equations for fat mass and percentage body fat were 93.2% and 76.4% for android and 91.4% and 66.5% for gynoid, respectively. The limits of agreement for the fat mass and percentage fat were -0.06 ± 0.87 kg and -0.11% ± 1.97% for android and -0.04 ± 1.58 kg and -0.19% ± 4.27% for gynoid. Prediction values for fat mass and percentage fat were 94.6% and 88.9% for total body, 93.9% and 71.0% for trunk, and 92.4% and 64.1% for leg, respectively. The three-dimensional (3D) SBI produces reliable parameters that can predict android and gynoid as well as total and regional (trunk, leg) fat mass.

  8. Synchrotron soft X-ray imaging and fluorescence microscopy reveal novel features of asbestos body morphology and composition in human lung tissues

    Directory of Open Access Journals (Sweden)

    Polentarutti Maurizio

    2011-02-01

    Full Text Available Abstract Background Occupational or environmental exposure to asbestos fibres is associated with pleural and parenchymal lung diseases. A histopathologic hallmark of exposure to asbestos is the presence in lung parenchyma of the so-called asbestos bodies. They are the final product of biomineralization processes resulting in deposition of endogenous iron and organic matter (mainly proteins around the inhaled asbestos fibres. For shedding light on the formation mechanisms of asbestos bodies it is of fundamental importance to characterize at the same length scales not only their structural morphology and chemical composition but also to correlate them to the possible alterations in the local composition of the surrounding tissues. Here we report the first correlative morphological and chemical characterization of untreated paraffinated histological lung tissue samples with asbestos bodies by means of soft X-ray imaging and X-Ray Fluorescence (XRF microscopy, which reveals new features in the elemental lateral distribution. Results The X-ray absorption and phase contrast images and the simultaneously monitored XRF maps of tissue samples have revealed the location, distribution and elemental composition of asbestos bodies and associated nanometric structures. The observed specific morphology and differences in the local Si, Fe, O and Mg content provide distinct fingerprints characteristic for the core asbestos fibre and the ferruginous body. The highest Si content is found in the asbestos fibre, while the shell and ferruginous bodies are characterized by strongly increased content of Mg, Fe and O compared to the adjacent tissue. The XRF and SEM-EDX analyses of the extracted asbestos bodies confirmed an enhanced Mg deposition in the organic asbestos coating. Conclusions The present report demonstrates the potential of the advanced synchrotron-based X-ray imaging and microspectroscopy techniques for studying the response of the lung tissue to the

  9. Synchrotron soft X-ray imaging and fluorescence microscopy reveal novel features of asbestos body morphology and composition in human lung tissues.

    Science.gov (United States)

    Pascolo, Lorella; Gianoncelli, Alessandra; Kaulich, Burkhard; Rizzardi, Clara; Schneider, Manuela; Bottin, Cristina; Polentarutti, Maurizio; Kiskinova, Maya; Longoni, Antonio; Melato, Mauro

    2011-02-07

    Occupational or environmental exposure to asbestos fibres is associated with pleural and parenchymal lung diseases. A histopathologic hallmark of exposure to asbestos is the presence in lung parenchyma of the so-called asbestos bodies. They are the final product of biomineralization processes resulting in deposition of endogenous iron and organic matter (mainly proteins) around the inhaled asbestos fibres. For shedding light on the formation mechanisms of asbestos bodies it is of fundamental importance to characterize at the same length scales not only their structural morphology and chemical composition but also to correlate them to the possible alterations in the local composition of the surrounding tissues. Here we report the first correlative morphological and chemical characterization of untreated paraffinated histological lung tissue samples with asbestos bodies by means of soft X-ray imaging and X-Ray Fluorescence (XRF) microscopy, which reveals new features in the elemental lateral distribution. The X-ray absorption and phase contrast images and the simultaneously monitored XRF maps of tissue samples have revealed the location, distribution and elemental composition of asbestos bodies and associated nanometric structures. The observed specific morphology and differences in the local Si, Fe, O and Mg content provide distinct fingerprints characteristic for the core asbestos fibre and the ferruginous body. The highest Si content is found in the asbestos fibre, while the shell and ferruginous bodies are characterized by strongly increased content of Mg, Fe and O compared to the adjacent tissue. The XRF and SEM-EDX analyses of the extracted asbestos bodies confirmed an enhanced Mg deposition in the organic asbestos coating. The present report demonstrates the potential of the advanced synchrotron-based X-ray imaging and microspectroscopy techniques for studying the response of the lung tissue to the presence of asbestos fibres. The new results obtained by

  10. Change in fat-free mass assessed by bioelectrical impedance, total body potassium and dual energy X-ray absorptiometry during prolonged weight loss

    DEFF Research Database (Denmark)

    Hendel, H W; Gotfredsen, A; Højgaard, L

    1996-01-01

    A total of 16 obese women (body mass index (BMI) 30-43 kg m(-2)) participated in a weight reduction study. Before and after a weight loss of 11.7 +/- 7.4 kg (mean +/- SD), body composition was assessed by dual energy X-ray absorptiometry (DXA), and total body potassium counting (TBK). These measu......A total of 16 obese women (body mass index (BMI) 30-43 kg m(-2)) participated in a weight reduction study. Before and after a weight loss of 11.7 +/- 7.4 kg (mean +/- SD), body composition was assessed by dual energy X-ray absorptiometry (DXA), and total body potassium counting (TBK......). These measurements were compared with bioimpedance analysis (BIA) by applying 11 predictive BIA equations published in the literature. Predictive equations for the present study population were developed, with the use of fat-free mass (FFM) as assessed by TBK and DXA as references in multiple regression analysis....... The results of the BIA equations varied widely; FFM was generally overestimated by BIA as compared with DXA and TBK before and after weight loss. During weight loss, the FFM did not change, as estimated by DXA (1.3 +/- 2.3 kg, p > 0.05) and TBK (0.9 +/- 2.9 kg, p > 0.05). The recorded change in impedance (R...

  11. Change in fat-free mass assessed by bioelectrical impedance, total body potassium and dual energy X-ray absorptiometry during prolonged weight loss

    DEFF Research Database (Denmark)

    Hendel, H W; Gotfredsen, A; Højgaard, L

    1996-01-01

    A total of 16 obese women (body mass index (BMI) 30-43 kg m(-2)) participated in a weight reduction study. Before and after a weight loss of 11.7 +/- 7.4 kg (mean +/- SD), body composition was assessed by dual energy X-ray absorptiometry (DXA), and total body potassium counting (TBK). These measu......A total of 16 obese women (body mass index (BMI) 30-43 kg m(-2)) participated in a weight reduction study. Before and after a weight loss of 11.7 +/- 7.4 kg (mean +/- SD), body composition was assessed by dual energy X-ray absorptiometry (DXA), and total body potassium counting (TBK....... The results of the BIA equations varied widely; FFM was generally overestimated by BIA as compared with DXA and TBK before and after weight loss. During weight loss, the FFM did not change, as estimated by DXA (1.3 +/- 2.3 kg, p > 0.05) and TBK (0.9 +/- 2.9 kg, p > 0.05). The recorded change in impedance (R......) was also insignificant. Three BIA equations from the literature, which were not specific for the degree of obesity in the present study group, predicted changes in FFM (from 0.5 + 3.6 to 2.4 +/- 4.4kg, p > 0.05) that were comparable with those estimated by the reference methods. Eight equations from...

  12. Use of dual-energy X-ray absorptiometry in obese individuals: The possibility to estimate whole body composition from DXA half-body scans

    International Nuclear Information System (INIS)

    Lundqvist, K.; Neovius, M.; Grigorenko, A.; Nordenstroem, J.; Roessner, S.

    2009-01-01

    Background: Because of its high accuracy, dual-energy X-ray absorptiometry (DXA) has become one of the most frequently used methods for estimating human body composition. One limiting factor concerning measuring obese people with the DXA technique is the size of the scanning area. Objective: To explore the possibility of estimating whole body composition from half-body scans before and after weight reduction, and compare the results with densitometry measurements. Design: Intervention study of 15 obese adults (age 47.2 ± 13.4; BMI 35.9 ± 3.1) who were measured with full- and half-body DXA scans before and after a 7-week weight loss program. On both occasions, body composition was also assessed with air-displacement plethysmography (ADP). Results: The mean weight loss at follow-up was 14.9 ± 4.1 kg (5.0 kg/m 2 ), corresponding to a 14% decrease in body weight. When comparing the results from full- and half-body DXA, between 96% and 98% of the variance was explained. At baseline, %Body Fat (%BF) did not differ significantly between full and half-body measurements (0.6, -0.1-1.3), but the half-body method overestimated it by 1.0% (0.2-1.8) at follow-up. On the contrary, the difference between DXA and ADP in the assessment of %BF was both significant and of large magnitude (5.2; 2.4-8.0) at baseline, while non-significant and near zero (0.4; -1.3-2.2) at follow-up when the subjects had lost a significant amount of weight. Conclusion: The results obtained from half-body DXA scans can accurately predict whole body composition, as measured by full-body DXA, before and after significant weight reduction, in obese patients who barely fit into the scanning area. However, increasing discordance between DXA and ADP with increasing adiposity was seen, indicating that the measurements might not be as reliable on extreme obese subjects as on normal and overweight ditto

  13. Use of dual-energy X-ray absorptiometry in obese individuals: The possibility to estimate whole body composition from DXA half-body scans

    Energy Technology Data Exchange (ETDEWEB)

    Lundqvist, K. [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital, SE-171 76 Stockholm (Sweden)], E-mail: kent.lundqvist@karolinska.se; Neovius, M. [Obesity Unit, Department of Medicine, Karolinska Institutet, Karolinska University Hospital, SE-141 86 Stockholm (Sweden); Grigorenko, A. [Research and Development Unit, YLab Wellcare Institute, SE-113 60 Stockholm (Sweden); Nordenstroem, J. [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital, SE-171 76 Stockholm (Sweden); Roessner, S. [Obesity Unit, Department of Medicine, Karolinska Institutet, Karolinska University Hospital, SE-141 86 Stockholm (Sweden)

    2009-02-15

    Background: Because of its high accuracy, dual-energy X-ray absorptiometry (DXA) has become one of the most frequently used methods for estimating human body composition. One limiting factor concerning measuring obese people with the DXA technique is the size of the scanning area. Objective: To explore the possibility of estimating whole body composition from half-body scans before and after weight reduction, and compare the results with densitometry measurements. Design: Intervention study of 15 obese adults (age 47.2 {+-} 13.4; BMI 35.9 {+-} 3.1) who were measured with full- and half-body DXA scans before and after a 7-week weight loss program. On both occasions, body composition was also assessed with air-displacement plethysmography (ADP). Results: The mean weight loss at follow-up was 14.9 {+-} 4.1 kg (5.0 kg/m{sup 2}), corresponding to a 14% decrease in body weight. When comparing the results from full- and half-body DXA, between 96% and 98% of the variance was explained. At baseline, %Body Fat (%BF) did not differ significantly between full and half-body measurements (0.6, -0.1-1.3), but the half-body method overestimated it by 1.0% (0.2-1.8) at follow-up. On the contrary, the difference between DXA and ADP in the assessment of %BF was both significant and of large magnitude (5.2; 2.4-8.0) at baseline, while non-significant and near zero (0.4; -1.3-2.2) at follow-up when the subjects had lost a significant amount of weight. Conclusion: The results obtained from half-body DXA scans can accurately predict whole body composition, as measured by full-body DXA, before and after significant weight reduction, in obese patients who barely fit into the scanning area. However, increasing discordance between DXA and ADP with increasing adiposity was seen, indicating that the measurements might not be as reliable on extreme obese subjects as on normal and overweight ditto.

  14. X-ray holography

    CERN Document Server

    Faigel, G; Belakhovsky, M; Marchesini, S; Bortel, G

    2003-01-01

    In the last decade holographic methods using hard X-rays were developed. They are able to resolve atomic distances, and can give the 3D arrangement of atoms around a selected element. Therefore, hard X-ray holography has potential applications in chemistry, biology and physics. In this article we give a general description of these methods and discuss the developments in the experimental technique. The capabilities of hard X-ray holography are demonstrated by examples.

  15. X-ray holography

    International Nuclear Information System (INIS)

    Faigel, G.; Tegze, M.; Belakhovsky, M.; Marchesini, S.; Bortel, G.

    2003-01-01

    In the last decade holographic methods using hard X-rays were developed. They are able to resolve atomic distances, and can give the 3D arrangement of atoms around a selected element. Therefore, hard X-ray holography has potential applications in chemistry, biology and physics. In this article we give a general description of these methods and discuss the developments in the experimental technique. The capabilities of hard X-ray holography are demonstrated by examples

  16. Ultrafast X-ray Sources

    International Nuclear Information System (INIS)

    Neil, George

    2010-01-01

    Since before the scattering of X-rays off of DNA led to the first understanding of the double helix structure, sources of X-rays have been an essential tool for scientists examining the structure and interactions of matter. The resolution of a microscope is proportional to the wavelength of light so x-rays can see much finer structures than visible light, down to single atoms. In addition, the energy of X-rays is resonant with the core atomic levels of atoms so with appropriate wavelengths the placement of specific atoms in a large molecule can be determined. Over 10,000 scientists use synchrotron sources, storage rings of high energy electrons, each year worldwide. As an example of such use, virtually every picture of a protein or drug molecule that one sees in the scientific press is a reconstruction based on X-ray scattering of synchrotron light from the crystallized form of that molecule. Unfortunately those pictures are static and proteins work through configuration (shape) changes in response to energy transfer. To understand how biological systems work requires following the energy flow to these molecules and tracking how shape changes drive their interaction with other molecules. We'd like to be able to freeze the action of these molecules at various steps along the way with an X-ray strobe light. How fast does it have to be? To actually get a picture of a molecule in a fixed configuration requires X-ray pulses as short as 30 femtoseconds (1/30 of a millionth of a millionth of a second). To capture the energy flow through changes in electronic levels requires a faster strobe, less than 1 femtosecond And to acquire such information in smaller samples with higher accuracy demands brighter and brighter X-rays. Unfortunately modern synchrotrons (dubbed 3rd Generation Light Sources) cannot deliver such short bright pulses of X-rays. An entirely new approach is required, linear-accelerator (linac-)-based light sources termed 4th or Next Generation Light Sources

  17. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the table in the area of the body being imaged. When necessary, sandbags, pillows or other positioning devices will be used to help you ... have very controlled x-ray beams and dose control methods to minimize stray (scatter) ... imaged receive minimal radiation exposure. top of page ...

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different ... about radiology? Share your patient story here Images ... content. Related Articles and Media Radiation Dose in X-Ray and CT Exams ...

  19. Providing x-rays

    International Nuclear Information System (INIS)

    Mallozzi, P.J.; Epstein, H.M.

    1985-01-01

    This invention provides an apparatus for providing x-rays to an object that may be in an ordinary environment such as air at approximately atmospheric pressure. The apparatus comprises: means (typically a laser beam) for directing energy onto a target to produce x-rays of a selected spectrum and intensity at the target; a fluid-tight enclosure around the target; means for maintaining the pressure in the first enclosure substantially below atmospheric pressure; a fluid-tight second enclosure adjoining the first enclosure, the common wall portion having an opening large enough to permit x-rays to pass through but small enough to allow the pressure reducing means to evacuate gas from the first enclosure at least as fast as it enters through the opening; the second enclosure filled with a gas that is highly transparent to x-rays; the wall of the second enclosure to which the x-rays travel having a portion that is highly transparent to x-rays (usually a beryllium or plastic foil), so that the object to which the x-rays are to be provided may be located outside the second enclosure and adjacent thereto and thus receive the x-rays substantially unimpeded by air or other intervening matter. The apparatus is particularly suited to obtaining EXAFS (extended x-ray fine structure spectroscopy) data on a material

  20. Comparison of Dual Energy X-ray Absorptiometry and Bioimpedance in Assessing Body Composition and Nutrition in Peritoneal Dialysis Patients

    DEFF Research Database (Denmark)

    Popovic, Velena; Zerahn, Bo; Heaf, James Goya

    2017-01-01

    OBJECTIVE: Peritoneal dialysis (PD) patients are characterized by protein malnutrition and muscle wasting. Reliable, easy, and cheap methods for evaluating nutrition are desirable. Three methods are commonly available: dual-energy X-ray absorptiometry (DXA), bioimpedance (BI), and subjective global...... to LTI (BI) than LTI (DXA). Plasma albumin was correlated to LTI, FTI, and ICW/ht, and comorbidity to OH, clinical malnutrition, reduced FTI, but not LTI. CONCLUSION: Agreement between DXA and BI was high on a population basis but not at an individual level. Obesity and muscle wasting were common...

  1. Comparison of the Lunar Prodigy and iDXA Dual-Energy X-ray Absorptiometers for Assessing Total and Regional Body Composition.

    Science.gov (United States)

    Morrison, Shannon A; Petri, Robert M; Hunter, Heather L; Raju, Dheeraj; Gower, Barbara

    2016-01-01

    The objective of the study was to assess the agreement of the Lunar Prodigy with the newer Lunar iDXA dual-energy X-ray absorptiometer for determining total body and regional (arms, legs, trunk) bone mineral density (BMD), bone mineral content (BMC), fat mass (FM), lean tissue mass (LTM), total body mass, and percent fat. Ninety-two healthy adult males (n = 36) and females (n = 56) were scanned consecutively on the iDXA and the Prodigy dual-energy X-ray absorptiometers. For iDXA, relative to Prodigy, paired t tests indicated significantly lower estimates for total body and regional BMD and BMC (p Prodigy for total body and regional BMD estimates (p Prodigy, investigators should be aware that certain total body and regional estimates are significantly different. The greatest percent differences were observed for arm BMD, FM, and percent fat. Copyright © 2016 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  2. Near edge x-ray spectroscopy theory

    International Nuclear Information System (INIS)

    1994-01-01

    We propose to develop a quantitative theory of x-ray spectroscopies in the near edge region, within about 100 eV of threshold. These spectroscopies include XAFS (X-ray absorption fine structure), photoelectron diffraction (PD), and diffraction anomalous fine structure (DAFS), all of which are important tools for structural studies using synchrotron radiation x-ray sources. Of primary importance in these studies are many-body effects, such as the photoelectron self-energy, and inelastic losses. A better understanding of these quantities is needed to obtain theories without adjustable parameters. We propose both analytical and numerical calculations, the latter based on our x-ray spectroscopy codes FEFF

  3. Noninvasive measurements of body composition and body water via quantitative magnetic resonance, deuterium water, and dual-energy x-ray absorptiometry in awake and sedated dogs.

    Science.gov (United States)

    Zanghi, Brian M; Cupp, Carolyn J; Pan, Yuanlong; Tissot-Favre, Delphine G; Milgram, Norton W; Nagy, Tim R; Dobson, Howard

    2013-05-01

    To compare quantitative magnetic resonance (QMR), dual-energy x-ray absorptiometry (DXA), and deuterium oxide (D2O) methods for measurement of total body water (TBW), lean body mass (LBM), and fat mass (FM) in healthy dogs and to assess QMR accuracy. 58 Beagles (9 months to 11.5 years old). QMR scans were performed on awake dogs. A D2O tracer was administered (100 mg/kg, PO) immediately before dogs were sedated, which was followed by a second QMR or DXA scan. Jugular blood samples were collected before and 120 minutes after D2O administration. TBW, LBM, and FM determined via QMR were not significantly different between awake or sedated dogs, and means differed by only 2.0%, 2.2%, and 4.3%, respectively. Compared with results for D2O dilution, QMR significantly underestimated TBW (10.2%), LBM (13.4%), and FM (15.4%). Similarly, DXA underestimated LBM (7.3%) and FM (8.4%). A significant relationship was detected between FM measured via D2O dilution and QMR (r(2) > 0.89) or DXA (r(2) > 0.88). Even though means of TBW and LBM differed significantly between D2O dilution and QMR or DXA, values were highly related (r(2) > 0.92). QMR was useful for determining body composition in dogs and can be used to safely and rapidly acquire accurate data without the need for sedation or anesthesia. These benefits can facilitate frequent scans, particularly in geriatric, extremely young, or ill pets. Compared with the D2O dilution method, QMR correction equations provided accurate assessment over a range of body compositions.

  4. Is whole body bone mineral density measured by the dual energy X-ray absorptiometry applied to evaluate risk of osteoporosis among Japanese adult females?

    International Nuclear Information System (INIS)

    Sakai, Yumiko; Koike, George; Numata, Makoto; Taneda, Kiyoshi; Jingu, Sumie

    2010-01-01

    The purpose of this study is to measure whole body fat accurately, the dual energy X-ray absorptiometry (DXA) is widely utilized. Simultaneously, bone mineral density (BMD) of the whole body can also be measured. BMD is one of important information to diagnose osteoporosis. However, it is not established to use whole body BMD for this diagnosis. It is recommended that lumbar and/or hip BMD should be used for diagnosing osteoporosis by the guideline for prevention and treatment of osteoporosis. Although it is possible to measure whole body BMD and lumbar and/or hip BMD separately at the same visit, it is inevitable to expose patients to more X-ray. Therefore, an aim of this study is to elucidate the relationship between whole body BMD and lumbar BMD to find the cut off point of whole body BMD for screening of osteoporosis. Two hundred and thirty six Japanese adult females were ascertained to this study. Whole body BMD and lumbar BMD of each subject were measured with the use of Delphi W (Hologic, USA). One hundred and sixty five subjects were judged as possible osteoporosis (less than 80% of young adult mean (YAM) of lumbar BMD and/or definite fracture of lumbar vertebras). The cut off point of whole body BMD for screening possible osteoporosis was estimated by receiver operated characteristic (ROC) analysis. The cut off point of whole body BMD was 84% of YAM, equivalent to 80% of YAM of lumbar BMD, with the following sensitivity and specificity (0.84 and 0.79, respectively), indicating that whole body BMD could be used for screening osteoporosis. (author)

  5. Chest X-Ray

    Medline Plus

    Full Text Available ... loose, comfortable clothing. You may be asked to change into a gown. You may have some concerns about chest x-rays. However, it’s important to consider the likelihood of benefit to your health. While a chest x-ray use a tiny ...

  6. Chest X-Ray

    Medline Plus

    Full Text Available ... by Image/Video Gallery Your Radiologist Explains Chest X-ray Transcript Welcome to Radiology Info dot org! Hello, ... d like to talk with you about chest radiography also known as chest x-rays. Chest x- ...

  7. The tendency of medical electrical equipment - IEC 60601-2-54: Particular requirements for the basic safety and essential performance of x-ray equipment for radiography and radioscopy

    International Nuclear Information System (INIS)

    Roh, Young Hoon; Kim, Jung Min

    2015-01-01

    Medical electrical equipment - Part 1: General requirement for basic safety and essential performance of MFDS was revised as 3th edition and Medical electrical equipment Part 2-54: Particular requirements for the basic safety and essential performance of X-ray equipment will be expected to be announced as notification. Therefore this technical report was written to introduce provision of the particular requirements, replacement, addition, amendment. The purpose of this particular requirements is to secure requirements for basic safety and essential performance of X-ray equipment for radiography and radioscopy. X-ray high voltage generator, mechanical protective device, protection against radiation is included in this particular requirements. Medical electrical equipment - Part 1, Part 1-2, Part 1-3 is applied to this particular requirements. If the requirements is announced as notification, It is expected to widen understanding for basic safety and essential performance of X-ray equipment for radiography and radioscopy and play a part to internationalize of medical equipment

  8. Trace analysis in the atmosphere, water bodies and uranium ores by means of X-ray fluorescence

    International Nuclear Information System (INIS)

    Perez Novara, A.M.

    1986-01-01

    Analysis with X-ray fluorescence is an instrumental method that evaluates concentrations, at trace levels, of elements in samples of all kinds. The applications of this method are broad, specially useful in the analysis of metals as contaminators in air and water, and as impurities in minerals. The preparation of the samples is very important to obtain good accuracy, and at the same time, you should make a series of standards of known concentrations so you can compare the counting of each sample against the standard, for each of the elements. You should make, depending on the nature of the sample, several corrections with respect to the background, interferences, overlaps, or for effects of a third element. (author)

  9. Theory of inelastic scattering and absorption of X-rays

    CERN Document Server

    Veenendaal, Michel van

    2015-01-01

    This comprehensive, self-contained guide to X-ray spectroscopy will equip you with everything you need to begin extracting the maximum amount of information available from X-ray spectra. Key topics such as the interaction between X-rays and matter, the basic theory of spectroscopy, and selection and sum rules, are introduced from the ground up, providing a solid theoretical grounding. The book also introduces core underlying concepts such as atomic structure, solid-state effects, the fundamentals of tensor algebra and group theory, many-body interactions, scattering theory, and response functions, placing spectroscopy within a broader conceptual framework, and encouraging a deep understanding of this essential theoretical background. Suitable for graduate students, researchers, materials scientists and optical engineers, this is the definitive guide to the theory behind this powerful and widely used technique.

  10. X-ray tubes for computed tomography

    International Nuclear Information System (INIS)

    Kotabe, Munenori; Sado, Noriyuki; Tachiki, Shigeru; Kitsuya, Minoru

    1979-01-01

    The X-ray tomography by computer processing (CT) is rapidly spreading because of the capabilities to obtain useful diagnostic information quantitatively, which was not able to be obtained by conventional X-ray photography, and to perform no-intrusion inspection, because it can picture the difference of X-ray absorption coefficient of several per cent in the soft tissues inside craniums. As the X-ray tubes to meet these requirements, the fixed anode X-ray tubes having high continuous rating are required for head CT, while the rotary anode X-ray tubes having the large cumulative heat capacity of anodes for whole body CT. Hitachi Ltd. has developed the X-ray tubes of type H 7129 of 4 kW rating for head CT and of type UJ-6FC-05V of 300 kHU (heat unit) for whole body CT. The specifications required for respective X-ray tubes include several items, and the maximum working tube voltage, focusing dimensions, long or short term maximum input and others are reported for the above described tubes. The performance centering around the loading life-time is described. In the tubes for whole body CT, repeated loading is also investigated. For the assumed input of 70,000 HU/slice, repeated loading of 10 times or more is possible in both cases when the input is repeatedly applied at loading intervals of 90 and 120 sec. (Wakatsuki, Y.)

  11. The influence of body composition assessed by dual-energy x-ray absorptiometry on functional capacity of patients with chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Gualberto Ruas

    Full Text Available INTRODUCTION: The individual with chronic obstructive pulmonary disease (COPD can experience a significant reduction of body composition, peripheral muscle dysfunction, resulting in a negative influence on functional capacity. OBJECTIVES: To analyze the influence of body composition assessed by dual-energy x-ray absorptiometry on functional capacity of patients with chronic obstructive pulmonary disease (COPD. MATERIALS AND METHODS: Eleven male patients with COPD (COPDG, seven presenting moderate obstruction and four severe, and 11 sedentary male subjects (CG were evaluated by dual-energy x-ray absorptiometry to assess their body composition. All subjects also performed the 6-minute walk test (6MWT and Step Test (6MST to assess their functional capacity. RESULTS: No significant differences were found between groups for anthropometric data such as age, weight, height and body mass index (BMI. However, the COPDG presented Forced Vital Capacity (FVC, Forced Expiratory Volume in one second (FEV1, FEV1/FVC ratio, Maximal Voluntary Ventilation (MVV, Walked Distance (WD and Number of Steps (NS significantly lower than the CG (p < 0.05, Student's t-test. The Body Bone Mass (BBM, BBM%, Lean Mass (LM, LM%, and Right Lower Limb (RLL and Left Lower Limb (LLL were significantly lower in the COPDG when compared with the CG, presenting statistically significant positive correlations with 6MWT's WD and 6MST's NS (p < 0.05, Pearson's test. CONCLUSION: We conclude that body composition is an important prognostic factor for patients with COPD, which reinforces the importance of assessing body composition by dual-energy absorptiometry since it has demonstrated with satisfactory accuracy in clinical practice. Moreover, it is a useful parameter for evaluation and reassessment in pulmonary rehabilitation programs.

  12. X-ray generator

    International Nuclear Information System (INIS)

    Dawson, J.M.

    1976-01-01

    An apparatus and a method are described for producing coherent secondary x-rays that are controlled as to direction by illuminating a mixture of high z and low z gases with an intense burst of primary x-rays. The primary x-rays are produced with a laser activated plasma, and these x-rays strip off the electrons of the high z atoms in the lasing medium, while the low z atoms retain their electrons. The neutral atoms transfer electrons to highly excited states of the highly stripped high z ions giving an inverted population which produces the desired coherent x-rays. In one embodiment, a laser, light beam provides a laser spark that produces the intense burst of coherent x-rays that illuminates the mixture of high z and low z gases, whereby the high z atoms are stripped while the low z ones are not, giving the desired mixture of highly ionized and neutral atoms. Means for magnetically confining and stabilizing the plasma are disclosed for controlling the direction of the x-rays

  13. Estimation of stature and length of limb segments in children and adolescents from whole-body dual-energy X-ray absorptiometry scans

    International Nuclear Information System (INIS)

    Abrahamyan, Davit O.; Gazarian, Aram; Braillon, Pierre M.

    2008-01-01

    Anthropometric standards vary among different populations, and renewal of these reference values is necessary. To produce formulae for the assessment of limb segment lengths. Whole-body dual-energy X-ray absorptiometry scans of 413 Caucasian children and adolescents (170 boys, 243 girls) aged from 6 to 18 years were retrospectively analysed. Body height and the lengths of four long bones (humerus, radius, femur and tibia) were measured. The validity (concurrent validity) and reproducibility (intraobserver reliability) of the measurement technique were tested. High linear correlations (r > 0.9) were found between the mentioned five longitudinal measures. Corresponding linear regression equations for the most important relationships were derived. The tests of validity and reproducibility revealed a good degree of precision of the applied technique. The reference formulae obtained from the analysis of whole-body DEXA scans will be useful for anthropologists, and forensic and nutrition specialists, as well as for prosthetists and paediatric orthopaedic surgeons. (orig.)

  14. X-ray apparatus

    International Nuclear Information System (INIS)

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

    1976-01-01

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

  15. X-ray detector

    International Nuclear Information System (INIS)

    Whetten, N.R.; Houston, J.M.

    1977-01-01

    An ionization chamber for use in determining the spatial distribution of x-ray photons in tomography systems comprises a plurality of substantially parallel, planar anodes separated by parallel, planar cathodes and enclosed in a gas of high atomic weight at a pressure from approximately 10 atmospheres to approximately 50 atmospheres. The cathode and anode structures comprise metals which are substantially opaque to x-ray radiation and thereby tend to reduce the resolution limiting effects of x-ray fluoresence in the gas. In another embodiment of the invention the anodes comprise parallel conductive bars disposed between two planar cathodes. Guard rings eliminate surface leakage currents between adjacent electrodes. 8 figures

  16. Bone X-Ray (Radiography)

    Medline Plus

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

  17. Panoramic Dental X-Ray

    Science.gov (United States)

    ... Resources Professions Site Index A-Z Panoramic Dental X-ray Panoramic dental x-ray uses a very small ... limitations of Panoramic X-ray? What is Panoramic X-ray? Panoramic radiography , also called panoramic x-ray , is ...

  18. Bone X-Ray (Radiography)

    Medline Plus

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

  19. 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 ... of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive ...

  20. Abdomen X-Ray (Radiography)

    Science.gov (United States)

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

  1. X-Ray Exam: Hip

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español X-Ray Exam: Hip KidsHealth / For Parents / X-Ray Exam: ... darker. An X-ray technician takes the X-rays. An X-ray technician in the radiology department of a ...

  2. Bone X-Ray (Radiography)

    Medline Plus

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

  3. Lumbosacral spine x-ray

    Science.gov (United States)

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

  4. Bone X-Ray (Radiography)

    Medline Plus

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

  5. Preliminary X-ray diffraction analysis of CfaA, a molecular chaperone essential for the assembly of CFA/I fimbriae of human enterotoxigenic Escherichia coli.

    Science.gov (United States)

    Bao, Rui; Esser, Lothar; Poole, Steven; McVeigh, Annette; Chen, Yu Xing; Savarino, Stephen J; Xia, Di

    2014-02-01

    Understanding of pilus bioassembly in Gram-negative bacteria stems mainly from studies of P pili and type 1 fimbriae of uropathogenic Escherichia coli, which are mediated by the classic chaperone-usher pathway (CUP). However, CFA/I fimbriae, a class 5 fimbria and intestinal colonization factor for enterotoxigenic E. coli (ETEC), are proposed to assemble via the alternate chaperone pathway (ACP). Both CUP and ACP fimbrial bioassembly pathways require the function of a periplasmic chaperone, but their corresponding proteins share very low similarity in primary sequence. Here, the crystallization of the CFA/I periplasmic chaperone CfaA by the hanging-drop vapor-diffusion method is reported. X-ray diffraction data sets were collected from a native CfaA crystal to 2 Å resolution and to 1.8 and 2.8 Å resolution, respectively, from a lead and a platinum derivative. These crystals displayed the symmetry of space group C2, with unit-cell parameters a = 103.6, b = 28.68, c = 90.60 Å, β = 119.7°. Initial phases were derived from multiple isomorphous replacement with anomalous scattering experiments using the data from the platinum and lead derivatives. This resulted in an interpretable electron-density map showing one CfaA molecule in an asymmetric unit. Sequence assignments were aided by anomalous signals from the heavy-atom derivatives. Refinement of the atomic model of CfaA is ongoing, which is expected to further understanding of the essential aspects and allowable variations in tertiary structure of the greater family of chaperones involved in chaperone-usher mediated bioassembly.

  6. Chest X-Ray

    Medline Plus

    Full Text Available ... Radiology and You Take our survey Sponsored by Image/Video Gallery Your Radiologist Explains Chest X-ray ... posted: How to Obtain and Share Your Medical Images Movement Disorders Video: The Basketball Game: An MRI ...

  7. X-ray tubes

    International Nuclear Information System (INIS)

    Young, R.W.

    1979-01-01

    A form of x-ray tube is described which provides satisfactory focussing of the electron beam when the beam extends for several feet from gun to target. Such a tube can be used for computerised tomographic scanning. (UK)

  8. Chest X-Ray

    Medline Plus

    Full Text Available ... Site Index A-Z Spotlight February is American Heart Month Recently posted: Carotid Intima-Media Thickness Test ... x-ray is used to evaluate the lungs, heart and chest wall and may be used to ...

  9. Chest X-Ray

    Medline Plus

    Full Text Available ... Abdominal Ultrasound Video: Pelvic Ultrasound Medical Imaging Costs Radiology and You Take our survey Sponsored by Image/ ... Radiologist Explains Chest X-ray Transcript Welcome to Radiology Info dot org! Hello, I’m Dr. Geoffrey ...

  10. Chest X-Ray

    Medline Plus

    Full Text Available ... exams and use a very small dose of ionizing radiation to produce pictures of the inside of the ... chest x-ray use a tiny dose of ionizing radiation, the benefit of an accurate diagnosis far outweighs ...

  11. Chest X-Ray

    Medline Plus

    Full Text Available ... accurate diagnosis far outweighs any risk. For more information about chest x-rays, visit Radiology Info dot ... Inc. (RSNA). To help ensure current and accurate information, we do not permit copying but encourage linking ...

  12. Chest X-Ray

    Medline Plus

    Full Text Available ... and You Take our survey Sponsored by Image/Video Gallery Your Radiologist Explains Chest X-ray Transcript ... Carotid Intima-Media Thickness Test Medical Imaging Costs Video: Abdominal Ultrasound Video: Pelvic Ultrasound Radiology and You ...

  13. Chest X-Ray

    Medline Plus

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

  14. Chest X-Ray

    Medline Plus

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

  15. Chest X-Ray

    Medline Plus

    Full Text Available ... and use a very small dose of ionizing radiation to produce pictures of the inside of the ... x-ray use a tiny dose of ionizing radiation, the benefit of an accurate diagnosis far outweighs ...

  16. Chest X-Ray

    Medline Plus

    Full Text Available ... Index A-Z Spotlight March is National Colorectal Cancer Awareness Month Recently posted: Carotid Intima-Media Thickness ... of lung conditions such as pneumonia, emphysema and cancer. A chest x-ray requires no special preparation. ...

  17. Chest X-Ray

    Medline Plus

    Full Text Available ... Index A-Z Spotlight March is National Colorectal Cancer Awareness Month Recently posted: How to Obtain and ... of lung conditions such as pneumonia, emphysema and cancer. A chest x-ray requires no special preparation. ...

  18. Chest X-Ray

    Medline Plus

    Full Text Available ... Index A-Z Spotlight March is National Colorectal Cancer Awareness Month Recently posted: Video: The Basketball Game: ... of lung conditions such as pneumonia, emphysema and cancer. A chest x-ray requires no special preparation. ...

  19. X-Ray Lasers

    Science.gov (United States)

    Eder, David C.

    1998-05-01

    We provide an overview of the status of x-ray laser development worldwide with particular attention given to activities at LLNL. Since the demonstration of x-ray lasing 14 years ago there has been major progress in achieving shorter wavelengths, higher energies per pulse, higher efficiency, shorter pulse durations, etc. Original x-ray lasers used large kJ class lasers to achieve lasing in mid-Z materials with electron collisional pumping in the highly stripped ion being the most successful process for populating the upper-laser state. The two most common electron configurations for these collisional x-ray lasers are Ne-like and Ni-like ions. Through the use of prepulses and short picosecond driving pulses, transient collisional x-ray lasing schemes have been demonstrated using lasers with only a few Joules per pulse. An interesting aspect of these lasers is the time lag in reaching ionization equilibrium helps in obtaining high gain coefficients. A different approach to x-ray lasing is also being studied where lasing occurs in a singly ionized ion following innershell photoionization. The major requirement of the driving laser in this case is an ultrashort pulse duration (rise time to achieve lasing prior to collisional ionization of outershell electrons. In the area of applications, most of the work has been for single pulse experiments such as plasma and biological imaging. However, many of the new x-ray lasers achieve high average power by having a reasonable repetition rate of order 10 Hz and we briefly discuss relevant applications for these x-ray lasers. This work performed under the auspices of US DOE by LLNL under Contract No. W-7405-Eng-48.

  20. X-Ray Optics

    Science.gov (United States)

    1990-01-01

    samples. Another exciting application of microbeam of x-rays is in that of high pressure x-ray diffraction from small samples. Along this line, Yan...will be presented by Jonathan in February at the Physics and Chemistry of Semiconductor Interfaces conference and in March at the American Physical...VUV9 conference this summer. Jeff has also worked on developing software that makes use of the scattering factor tables for both microvax and IBM PC

  1. Bone X-Ray (Radiography)

    Medline Plus

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

  2. Bone X-Ray (Radiography)

    Medline Plus

    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 ...

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... holds the x-ray film or image recording plate . Sometimes the x-ray is taken with the ... an x-ray film holder or image recording plate is placed beneath the patient. top of page ...

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose ... Medicine Radiation Safety How to Read Your Radiology Report Images related to X-ray (Radiography) - Bone Sponsored ...

  5. Bone X-Ray (Radiography)

    Medline Plus

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

  6. Prenatal pesticide exposure and PON1 genotype associated with adolescent body fat distribution evaluated by dual X-ray absorptiometry (DXA)

    DEFF Research Database (Denmark)

    Tinggaard, Jeanette; Wohlfahrt-Veje, C.; Husby, S

    2016-01-01

    Many modern pesticides have endocrine disrupting abilities and early-life exposure may affect growth and disease risk later in life. Previously, we reported associations between prenatal pesticide exposure and higher childhood body fat content measured by anthropometry. The associations were...... affected by child PON1 Q192R genotype. We aimed to study whether prenatal pesticide exposure was still associated with body fat content and distribution in the children at puberty and the potential impact of both maternal and child PON1 Q192R genotype. In this prospective cohort study of 247 children born...... by occupationally exposed or unexposed women (greenhouse workers and controls) two follow-up examinations (age 10-15 and 11-16 years) including simple anthropometry, skinfold measurements, pubertal staging and blood sampling were performed. Total and regional fat% was determined by dual X-ray absorptiometry (DXA...

  7. Percentage body fat by dual-energy X-ray absorptiometry is associated with menstrual recovery in adolescents with anorexia nervosa.

    Science.gov (United States)

    Pitts, Sarah; Blood, Emily; Divasta, Amy; Gordon, Catherine M

    2014-06-01

    To evaluate mediators of resumption of menses (ROM) in adolescents with anorexia nervosa (AN). Anthropometrics, body composition by dual-energy X-ray absorptiometry, hormonal studies, and responses to mental health screens were obtained at 6-month intervals for 18 months in 37 adolescents with AN randomized to the placebo arm of a double-blind treatment trial. Outcomes were compared between subjects with menstrual recovery and those without. Twenty-four subjects (65%) had ROM. Higher percentage body fat was associated with ROM (odds ratio, 1.19; 95% confidence interval, 1.06, 1.33; p adolescents with AN. Copyright © 2014 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  8. Methodology review: using dual-energy X-ray absorptiometry (DXA) for the assessment of body composition in athletes and active people.

    Science.gov (United States)

    Nana, Alisa; Slater, Gary J; Stewart, Arthur D; Burke, Louise M

    2015-04-01

    Dual energy X-ray absorptiometry (DXA) is rapidly becoming more accessible and popular as a technique to monitor body composition, especially in athletic populations. Although studies in sedentary populations have investigated the validity of DXA assessment of body composition, few studies have examined the issues of reliability in athletic populations and most studies which involve DXA measurements of body composition provide little information on their scanning protocols. This review presents a summary of the sources of error and variability in the measurement of body composition by DXA, and develops a theoretical model of best practice to standardize the conduct and analysis of a DXA scan. Components of this protocol include standardization of subject presentation (subjects rested, overnight-fasted and in minimal clothing) and positioning on the scanning bed (centrally aligned in a standard position using custom-made positioning aids) as well as manipulation of the automatic segmentation of regional areas of the scan results. Body composition assessment implemented with such protocol ensures a high level of precision, while still being practical in an athletic setting. This ensures that any small changes in body composition are confidently detected and correctly interpreted. The reporting requirements for studies involving DXA scans of body composition include details of the DXA machine and software, subject presentation and positioning protocols, and analysis protocols.

  9. Effect of ¹⁸F-FDG administration on measurements of bone mineral density and body composition by dual-energy X-ray absorptiometry.

    Science.gov (United States)

    Kim, Dae-Weung; Kim, Woo Hyoung; Kim, Myoung Hyoun; Kim, Seong Su; Mo, Eun Hee; Lee, Chun Ho; Kim, Chang Guhn

    2013-01-01

    The purpose of this study was to determine whether antecedent administration of ¹⁸F-fluorodeoxyglucose (FDG) used in positron emission tomography (PET) scanning results in corruption of bone mineral density (BMD) and body composition measured by dual-energy X-ray absorptiometry (DXA) system. DXA measurements of BMD and body composition had been performed twice, before and after ¹⁸F-FDG PET scan in 30 patients. The comparison of pre-values and post-values of all BMD values showed a decrease after the injection. However, only the decrease of whole-body BMD (WB-BMD) was statistically significant (p < 0.05). Whole-body fat mass had increased and whole-body lean body mass had decreased after the injection of ¹⁸F-FDG, and these were statistically significant (p < 0.05). There is statistically significant correlation between the injected ¹⁸F-FDG dose and a decrease of WB-BMD (r = -0.405; p < 0.05). The findings of this study suggest that when both ¹⁸F-FDG PET and DXA measurements for whole-body composition are performed in close-time proximity, ¹⁸F-FDG PET scans should follow the DXA measurement. Otherwise, BMD measurements of total femur or lumbar spine could be followed by ¹⁸F-FDG PET in close-time proximity. Copyright © 2013 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  10. Impact of hydration status on body composition as measured by dual energy X-ray absorptiometry in normal volunteers and patients on haemodialysis

    Energy Technology Data Exchange (ETDEWEB)

    Horber, F.F.; Thomi, F.; Casez, J.P.; Fonteille, J.; Jaeger, Ph. (University Hospital, Berne (Switzerland). Policlinic of Medicine)

    1992-10-01

    To evaluate the influence of hydration status on the estimation of body composition using dual-energy X-ray absorptiometry (DXA), six normal volunteers and seven patients on maintenance haemodialysis were investigated using two different DXA machines (Lunar DPX, Hologic QDR 1000/W). Normal volunteers were studied (Hologic QDR 1000/W) before and 1 h after ingestion of breakfast, lunch and dinner (drinking various amounts of liquids at each meal, 0.5-2.4 kg). Whereas bone mineral content and body fat mass did not change, lean body mass of the trunk increased as a consequence of the meals. Conversely in patients on haemodialysis (Lunar DPX), lean body mass decreased in all segments of the body as a consequence of removal of 0.9-4.4 kg of salt-containing fluid by haemodialysis (trunk 61%, legs 30%, arms 5.5% and rest of the body 3.5%), whereas bone mineral content and body fat mass remained unchanged. (author).

  11. Impact of hydration status on body composition as measured by dual energy X-ray absorptiometry in normal volunteers and patients on haemodialysis

    International Nuclear Information System (INIS)

    Horber, F.F.; Thomi, F.; Casez, J.P.; Fonteille, J.; Jaeger, Ph.

    1992-01-01

    To evaluate the influence of hydration status on the estimation of body composition using dual-energy X-ray absorptiometry (DXA), six normal volunteers and seven patients on maintenance haemodialysis were investigated using two different DXA machines (Lunar DPX, Hologic QDR 1000/W). Normal volunteers were studied (Hologic QDR 1000/W) before and 1 h after ingestion of breakfast, lunch and dinner (drinking various amounts of liquids at each meal, 0.5-2.4 kg). Whereas bone mineral content and body fat mass did not change, lean body mass of the trunk increased as a consequence of the meals. Conversely in patients on haemodialysis (Lunar DPX), lean body mass decreased in all segments of the body as a consequence of removal of 0.9-4.4 kg of salt-containing fluid by haemodialysis (trunk 61%, legs 30%, arms 5.5% and rest of the body 3.5%), whereas bone mineral content and body fat mass remained unchanged. (author)

  12. X-Ray Absorption with Transmission X-Ray Microscopes

    NARCIS (Netherlands)

    de Groot, F.M.F.

    2016-01-01

    In this section we focus on the use of transmission X-ray microscopy (TXM) to measure the XAS spectra. In the last decade a range of soft X-ray and hard X-ray TXM microscopes have been developed, allowing the measurement of XAS spectra with 10–100 nm resolution. In the hard X-ray range the TXM

  13. Bioelectrical impedance analysis to estimate body composition, and change in adiposity, in overweight and obese adolescents: comparison with dual-energy x-ray absorptiometry.

    Science.gov (United States)

    Wan, Ching S; Ward, Leigh C; Halim, Jocelyn; Gow, Megan L; Ho, Mandy; Briody, Julie N; Leung, Kelvin; Cowell, Chris T; Garnett, Sarah P

    2014-10-03

    There is a need for a practical, inexpensive method to assess body composition in obese adolescents. This study aimed to 1) compare body composition parameters estimated by a stand-on, multi-frequency bioelectrical impendence (BIA) device, using a) the manufacturers' equations, and b) published and derived equations with body composition measured by dual-energy x-ray absorptiometry (DXA) and 2) assess percentage body fat (%BF) change after a weight loss intervention. Participants were 66 obese adolescents, mean age (SD) 12.9 (2.0) years. Body composition was measured by Tanita BIA MC-180MA (Tanita BIA8) and DXA (GE-Lunar Prodigy). BIA resistance and reactance data at frequencies of 5, 50, 250 and 500 kHz, were used in published equations, and to generate a new prediction equation for fat-free mass (FFM) using a split-sample method. Approximately half (n = 34) of the adolescents had their body composition measured by DXA and BIA on two occasions, three to nine months apart. The correlations between FFM (kg), fat mass (kg) and %BF measured by BIA and DXA were 0.92, 0.93 and 0.78, respectively. The Tanita BIA8 manufacturers equations significantly (P obese adolescent.

  14. Practical Considerations for Body Composition Assessment of Adults with Class II/III Obesity Using Bioelectrical Impedance Analysis or Dual-Energy X-Ray Absorptiometry.

    Science.gov (United States)

    Johnson Stoklossa, Carlene A; Forhan, Mary; Padwal, Raj S; Gonzalez, Maria Cristina; Prado, Carla M

    2016-12-01

    The purpose of this review is to explore the practical considerations for body composition assessment of adults with class II/III obesity. Studies assessing adults (18-64 years) with a body mass index (BMI) ≥35 kg/m 2 with bioelectrical impedance analysis (BIA) and/or dual-energy X-ray absorptiometry (DXA) were included. Twelve studies met inclusion criteria. Five considerations were identified: variances in equipment and technology, equipment weight capacity, subject positioning, tissue penetration, and total body hydration. In subjects with BMI ≥35 kg/m 2 , BIA overestimated fat-free mass with scaling errors as BMI increased. DXA provided accurate and reliable body composition measures, but equipment-related barriers prevented assessment of some taller, wider, and heavier subjects. BIA is an unreliable method to assess body composition in class II/III obesity. Advancements in DXA technology (e.g., iDXA), methodology (e.g., subject positioning, longer scan times), and more inclusive testing criteria (e.g., use equipment limits not just BMI) may improve access and understanding of body composition in this cohort.

  15. The relation between dual energy X-ray absorptiometry measurements of body fat composition and plasma ghrelin in patients with end-stage renal disease

    International Nuclear Information System (INIS)

    Elsayed, Naglaa M.; Hamed, Soha T.; El-Khatib, Mohamed M.; El-Shehaby, Amal M.

    2009-01-01

    Objective was to clarify the role of ghrelin in malnutrition in uremia and its relationship to fat composition using dual x-ray absorptiometry (DXA). This is a cohort study including Group I: 60 patients with end stage renal disease (30 on hemodialysis [group IA] and 30 pre-dialysis [group IB]) and Group II: 20 controls. This study was carried out in Cairo University Hospital, Kasr Al-Aini, Cairo, Egypt in 2007. Body fat composition (total, differential and lean body mass) was assessed using DXA and plasma ghrelin was measured. Ghrelin was significantly higher in hemodialysis and pre-dialysis groups compared to the control group and higher in hemodialysis group compared to the pre-dialysis group. In hemodialysis, ghrelin was negatively correlated with weight, body mass index (BMI), and truncal fat mass, and positively correlated with serum creatinine, lean body mass. In control, plasma ghrelin showed negative correlation with weight, BMI, truncal fat mass and positive correlation with lean body mass. Ghrelin was markedly elevated in renal failure due to its decrease in excretion. Negative correlation between ghrelin and fat mass composition was detected in dialysis patients. Serial evaluation of body fat mass composition using DXA is recommended for assessment of nutritional status of those patients. (author)

  16. Radioprotection by dipyridamole in the aging mouse. Effects on lipid peroxidation in mouse liver, spleen and brain after whole-body X-ray irradiation

    International Nuclear Information System (INIS)

    Seino, Noritaka

    1995-01-01

    To investigate the radioprotective effect of dipyridamole in the aging mouse, the lipid peroxide content in aging mouse liver, spleen and brain irradiated by X-ray were measured both before and after injection of dipyridamole. The lipid peroxide content increased with aging from 2 months old to 16 months old in the mouse liver, spleen and brain. The content of lipid peroxide in the liver and spleen of the aging mouse was significantly increased in 7 days after whole-body irradiation with 8 Gy, but was unchanged in the brain. Dipyridamole, given before irradiation, significantly inhibited the increase of lipid peroxide after irradiation. These results suggest that dipyridamole may have radioprotective effects on aging mouse liver and spleen as well as on young mouse, and that inhibition of lipid peroxidation is a possible factor in the radioprotective effect of dipyridamole. (author)

  17. Autoradiographic studies of cell kinetics after whole body x-ray irradiation. Part 1. Mode of death of lethally injured proliferating subependymal cells in rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Gracheva, N.D.

    1982-03-01

    Autoradiographic tests were performed on proliferating subependymal cells derived from the brain of Wistar rats treated with /sup 3/H-thymidine, 60 to 80 min prior to whole-body x-ray irradiation with 50, 150, or 300 R. Evaluation of the time-dependent increase in the fraction of radio-labeled cells and the two-fold lower concentration of the label in pycnotic nuclei indicated that the lethally-injured cells which were irradiated in the early G/sub 2/ and S phases were subjected to mitotic, rather than interphase, death in the first post-radiation cell cycle. Such cells underwent mitosis ca. 2 h after irradiation, showing a 1 h lag phase vis-a-vis control cells, irrespective of the radiation dose. 25 references, 5 figures.

  18. Dual-energy X-ray absorptiometry, skinfold thickness and waist circumference for assessing body composition in ambulant and non-ambulant wheelchair games players

    Directory of Open Access Journals (Sweden)

    Annika eWillems

    2015-11-01

    Full Text Available Field-based assessments provide a cost–effective and accessible alternative to dual-energy X-ray absorptiometry (DXA for practitioners determining body composition in athletic populations. It remains unclear how the range of physical impairments classifiable in wheelchair sports may affect the utility of field-based body composition techniques. The present study assessed body composition using DXA in 14 wheelchair games players who were either wheelchair dependent (non-walkers; n =7 or relied on a wheelchair for sports participation only (walkers; n =7. Anthropometric measurements were used to predict body fat percentage with existing regression equations established for able-bodied persons by Sloan & Weir, Durnin & Womersley, Lean et al, Gallagher et al and Pongchaiyakul et al. In addition, linear regression analysis was performed to calculate the association between body fat percentage and BMI, waist circumference, sum of 6 skinfold thicknesses and sum of 8 skinfold thicknesses. Results showed that non-walkers had significantly lower total lean tissue mass (46.2±=6.6 kg vs. 59.4±8.2 kg, P =.006 and total body mass (65.8 ±4.2 kg vs. 79.4 ±14.9 kg; P =0.05 than walkers. Body fat percentage calculated from most existing regression equations was significantly lower than that from DXA, by 2 to 9% in walkers and 8 to14% in non-walkers. Of the anthropometric measurements, the sum of 8 skinfold thicknesses had the lowest standard error of estimation in predicting body fat content. In conclusion, existing anthropometric equations developed in able-bodied populations substantially underestimated body fat content in wheelchair athletes, particularly non-walkers. Impairment specific equations may be needed in wheelchair athletes.

  19. X-ray tube

    International Nuclear Information System (INIS)

    Webley, R.S.

    1975-01-01

    The object of the invention described is to provide an X-ray tube providing a scanned X-ray output which does not require a scanned electron beam. This is obtained by an X-ray tube including an anode which is rotatable about an axis, and a source of a beam of energy, for example an electron beam, arranged to impinge on a surface of the anode to generate X-radiation substantially at the region of incidence on the anode surface. The anode is rotatable about the axis to move the region of incidence over the surface. The anode is so shaped that the rotation causes the region of incidence to move in a predetermined manner relative to fixed parts of the tube so that the generated X-radiation is scanned in a predetermined manner relative to the tube. (UK)

  20. A comparison of skinfold anthropometry and dual-energy X-ray absorptiometry for the evaluation of body fat in cirrhotic patients.

    Science.gov (United States)

    Fiore, P; Merli, M; Andreoli, A; De Lorenzo, A; Masini, A; Ciuffa, L; Valeriano, V; Balotta, M T; Riggio, O

    1999-12-01

    Skinfold anthropometry has been used to evaluate the nutritional status in cirrhosis. Such estimates are based on the calculations which derive from healthy subjects and may not apply to cirrhotic patients. We aimed to calculate the limits of agreement between Skinfold anthropometry (SA) and dual-energy X-ray absorptiometry (DXA) in estimating body fat in cirrhotics. Forty cirrhotic patients were studied by both methods. The limits of agreement were estimated by the Bland and Altman method. Percentage body fat was similar when measured by DXA and SA (29.6 +/- 9.2 vs 28.9 +/- 7.5 %). Body fat mass was also similar (20.3 +/- 8.4 vs 20.3 +/- 7.7 kg). The limits of agreement between DXA and SA measurements were -7.04 (95%CI: -9.55 to -5.2) +8.56 (95%CI: +10.7 to +6.4.) in the assessment of percentage body fat and -5.32 (95%CI: -6.77 to -3.87) +5.24 (95%CI: +3.79 to +6.69) in the assessment of fat mass. Percentage body fat can be evaluated by SA or DXA with a difference of less then 5% in the majority of cirrhotic patients without overt fluid retention. This result is important when considering the large applicability of SA. Copyright 1999 Harcourt Publishers Ltd.

  1. X-Ray Crystallography Reagent

    Science.gov (United States)

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

    2003-01-01

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

  2. X-Ray Exam: Pelvis

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español X-Ray Exam: Pelvis KidsHealth / For Parents / X-Ray Exam: ... Ray Exam: Hip Broken Bones Getting an X-ray (Video) X-Ray (Video) View more Partner Message About Us ...

  3. X-Ray Exam: Forearm

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español X-Ray Exam: Forearm KidsHealth / For Parents / X-Ray Exam: ... Muscles, and Joints Broken Bones Getting an X-ray (Video) X-Ray (Video) View more Partner Message About Us ...

  4. X-Ray Exam: Foot

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español X-Ray Exam: Foot KidsHealth / For Parents / X-Ray Exam: ... Muscles, and Joints Broken Bones Getting an X-ray (Video) X-Ray (Video) View more Partner Message About Us ...

  5. X-Ray Exam: Wrist

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español X-Ray Exam: Wrist KidsHealth / For Parents / X-Ray Exam: ... Muscles, and Joints Broken Bones Getting an X-ray (Video) X-Ray (Video) View more Partner Message About Us ...

  6. Thoracic spine x-ray

    Science.gov (United States)

    Vertebral radiography; X-ray - spine; Thoracic x-ray; Spine x-ray; Thoracic spine films; Back films ... There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most ...

  7. X-Ray Exam: Finger

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español X-Ray Exam: Finger KidsHealth / For Parents / X-Ray Exam: ... Muscles, and Joints Broken Bones Getting an X-ray (Video) X-Ray (Video) View more Partner Message About Us ...

  8. Subluminous X-ray binaries

    NARCIS (Netherlands)

    Armas Padilla, M.

    2013-01-01

    The discovery of the first X-ray binary, Scorpius X-1, by Giacconi et al. (1962), marked the birth of X-ray astronomy. Following that discovery, many additional X-ray sources where found with the first generation of X-ray rockets and observatories (e.g., UHURU and Einstein). The short-timescale

  9. X-ray detector

    International Nuclear Information System (INIS)

    Houston, J.M.; Whetten, N.R.

    1981-01-01

    An ionization chamber for use in determining the spatial distribution of x-ray photons in tomography systems comprises a plurality of substantially parallel, planar anodes separated by parallel, planar cathodes and enclosed in a gas of high atomic weight at a pressure from approximately 10 atmospheres to approximately 50 atmospheres. The cathode and anode structures comprise metals which are substantially opaque to x-ray radiation and thereby tend to reduce the resolution limiting effects of xray fluoresence in the gas. In another embodiment of the invention the anodes comprise parallel conductive bars disposed between two planar cathodes. Guard rings eliminate surface leakage currents between adjacent electrodes

  10. X-ray masks

    International Nuclear Information System (INIS)

    Greenwood, J.C.; Satchell, D.W.

    1984-01-01

    In semiconductor manufacture, where X-ray irradiation is used, a thin silicon membrane can be used as an X-ray mask. This membrane has areas on which are patterns to define the regions to be irradiated. These regions are of antireflection material. With the thin, in the order of 3 microns, membranes used, fragility is a problem. Hence a number of ribs of silicon are formed integral with the membrane, and which are relatively thick, 5 to 10 microns. The ribs may be formed by localised deeper boron deposition followed by a selective etch. (author)

  11. Flash x-ray

    International Nuclear Information System (INIS)

    Johnson, Q.; Pellinen, D.

    1976-01-01

    The complementary techniques of flash x-ray radiography (FXR) and flash x-ray diffraction (FXD) provide access to a unique domain in nondestructive materials testing. FXR is useful in studies of macroscopic properties during extremely short time intervals, and FXD, the newer technique, is used in studies of microscopic properties. Although these techniques are similar in many respects, there are some substantial differences. FXD generally requires low-voltage, line-radiation sources and extremely accurate timing; FXR is usually less demanding. Phenomena which can be profitably studied by FXR often can also be studied by FXD to permit a complete materials characterization

  12. CRL X-ray tube

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  13. CRL X-RAY TUBE

    OpenAIRE

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

    2015-01-01

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

  14. X rays and condensed matter

    International Nuclear Information System (INIS)

    Daillant, J.

    1997-01-01

    After a historical review of the discovery and study of X rays, the various interaction processes between X rays and matter are described: Thomson scattering, Compton scattering, X-photon absorption through photoelectric effect, and magnetic scattering. X ray sources such as the European Synchrotron Radiation Facility (ESRF) are described. The various X-ray applications are presented: imagery such as X tomography, X microscopy, phase contrast; X-ray photoelectron spectroscopy and X-ray absorption spectroscopy; X-ray scattering and diffraction techniques

  15. Association of Serum Tumor Necrosis Factor-Related Apoptosis Inducing Ligand with Body Fat Distribution as Assessed by Dual X-Rays Absorptiometry

    Directory of Open Access Journals (Sweden)

    Carlo Cervellati

    2014-01-01

    Full Text Available A low chronic inflammation mediated by cytokine release is considered a major pathogenic mechanism accounting for the higher risk of cardiovascular disease in the overweight/obese population. In this context, although the existence of a possible interaction between soluble tumor necrosis factor- (TNF- related apoptosis inducing ligand (TRAIL and quantity and localization, of adiposity in the body has been hypothesized, no studies have yet investigated this link by radiologic techniques able to assess directly fat mass (FM in different body regions. To address this issue, we assessed body fat distribution by dual X-rays absorptiometry (DXA in a sample of 103 women and investigated the possible association between the derived adiposity measures and serum TRAIL concentration. The level of TRAIL showed a positive and independent correlation with arms FM (P<0.05, trunk FM (P<0.001 and trunk FM% (P<0.05, total FM and total FM% (P<0.001 for both, and an inverse association with legs FM% (P<0.05. Only trunk FM retained a significant correlation (P<0.05 with TRAIL after adjusting for all the other indices of regional adiposity. In conclusion, from our study it emerged a significant and independent association of serum TRAIL levels with overall, and, mainly, central adiposity. Further studies are needed to longitudinally investigate the cause-effect relationship between change in body fat distribution and TRAIL.

  16. Evaluation of Lunar Prodigy dual-energy X-ray absorptiometry for assessing body composition in healthy persons and patients by comparison with the criterion 4-component model.

    Science.gov (United States)

    Williams, Jane E; Wells, Jonathan C K; Wilson, Catherine M; Haroun, Dalia; Lucas, Alan; Fewtrell, Mary S

    2006-05-01

    Dual-energy X-ray absorptiometry (DXA) is widely used to assess body composition in research and clinical practice. Several studies have evaluated its accuracy in healthy persons; however, little attention has been directed to the same issue in patients. The objective was to compare the accuracy of the Lunar Prodigy DXA for body-composition analysis with that of the reference 4-component (4C) model in healthy subjects and in patients with 1 of 3 disease states. A total of 215 subjects aged 5.0-21.3 y (n = 122 healthy nonobese subjects, n = 55 obese patients, n = 26 cystic fibrosis patients, and n = 12 patients with glycogen storage disease). Fat mass (FM), fat-free mass (FFM), and weight were measured by DXA and the 4C model. The accuracy of DXA-measured body-composition outcomes differed significantly between groups. Factors independently predicting bias in weight, FM, FFM, and percentage body fat in multivariate models included age, sex, size, and disease state. Biases in FFM were not mirrored by equivalent opposite biases in FM because of confounding biases in weight. The bias of DXA varies according to the sex, size, fatness, and disease state of the subjects, which indicates that DXA is unreliable for patient case-control studies and for longitudinal studies of persons who undergo significant changes in nutritional status between measurements. A single correction factor cannot adjust for inconsistent biases.

  17. iDXA, Prodigy, and DPXL dual-energy X-ray absorptiometry whole-body scans: a cross-calibration study.

    Science.gov (United States)

    Hull, Holly; He, Qing; Thornton, John; Javed, Fahad; Allen, Lynn; Wang, Jack; Pierson, Richard N; Gallagher, Dympna

    2009-01-01

    Total body fat, lean, and bone mineral content (BMC) in addition to regional fat and lean mass values for arms, legs, and trunk were compared across a pencil-beam (Lunar DPXL) and 2 fan-beam (GE Lunar Prodigy and GE Lunar iDXA) dual-energy X-ray absorptiometry (DXA) systems. Subjects were a multiethnic sample of 99 healthy adult males (47%) and females (mean+/-SD: age, 46.3+/-16.9 yr; weight, 73.4+/-16.6 kg; height, 167.6+/-9.7 cm; body mass index, 26.0+/-5.2 kg/m2) who had whole-body scans performed within a 3-h period on the 3 systems. Repeated measures ANOVA was used to test the null hypothesis that the mean values for the 3 systems were equal. Translation equations between the methods were derived using regression techniques. Bone mineral content (BMC): For both genders, total BMC by iDXA was lower (pProdigy mean values (pProdigy (pProdigy only for arms (p<0.0007). These data were used to derive translation equations between systems. For several measurements, the differences between systems were related to gender. For estimation of BMC and body composition, there was high agreement between all DXA systems (R2=0.85-0.99). Even so, cross-calibration equations should be used to examine data across systems to avoid erroneous conclusions.

  18. X-ray beam generator

    International Nuclear Information System (INIS)

    Koller, T.J.; Randmer, J.A.

    1977-01-01

    A method of minimizing the preferential angular absorption of the divergent beam from an X-ray generator is described. The generator consists of an X-ray shielded housing with an X-ray transmissive window symmetrically placed in radial alignment with a focal spot area on a sloped target surface of an X-ray tube in the housing. The X-ray tube may be of the stationary anode type or of the rotating anode type. (U.K.)

  19. Utility of multifrequency bioelectrical impedance compared with dual-energy x-ray absorptiometry for assessment of total and regional body composition varies between men and women.

    Science.gov (United States)

    Anderson, Lindsey J; Erceg, David N; Schroeder, E Todd

    2012-07-01

    Multifrequency bioelectrical impedance analysis of body composition may be an appropriate alternative to dual-energy x-ray absorptiometry. We hypothesized that there would be no significant differences between dual-energy x-ray absorptiometry and either the Biospace (Los Angeles, CA, USA) InBody 520 or 720 multifrequency bioelectrical impedance analysis devices for total lean body mass (LBM), appendicular lean mass (ALM), trunk lean mass (TM), and total fat mass (FM) in 25 men and 25 women (including lean, healthy, and obese individuals according to body mass index), age 18 to 49 years, weight of 73.6 ± 15.4 kg. Both devices overestimated LBM in women (~2.5 kg, P < .001) and underestimated ALM in men (~3.0 kg, P < .05) and women (~1.0 kg, P < .05). The 720 overestimated FM in men (1.6 kg, P < .05) and underestimated TM in women (0.6 kg, P ≤ .05). Regression analyses in men revealed R² (0.87-0.91), standard error of the estimate (SEE; 2.3-2.8 kg), and limits of agreement (LOAs; 4.5-5.7 kg) for LBM; R(2) (0.62-0.87), SEE (1.5-2.6 kg), and LOA (3.2-6.0 kg) for ALM; R² (0.52-0.71), SEE (2.4-3.0 kg), and LOA (4.6-6.1 kg) for TM; and R(2) (0.87-0.93), SEE (1.9-2.6 kg), and LOA (5.9-6.2 kg) for FM. Regression analyses in women revealed R² (0.87-0.88), SEE (1.8-1.9 kg), and LOA (4.1-4.2 kg) for LBM; R² (0.78-0.79), SEE (1.4-1.5 kg), and LOA (2.7-2.9 kg) for ALM; R² (0.76-0.77), SEE (1.0 kg), and LOA (2.2-2.3 kg) for TM; and R² (0.95), SEE (2.2 kg), and LOA (4.3-4.4 kg) for FM. The InBody 520 and 720 are valid estimators of LBM and FM in men and of LBM, ALM, and FM in women; the 720 and 520 are valid estimators of TM in men and women, respectively. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Energetic Processing of N2:CH4 Ices Employing X-Rays and Swift Ions: Implications for Icy Bodies in the Outer Solar System

    Science.gov (United States)

    Vasconcelos, Fredson de A.; Pilling, Sergio; Rocha, Will R. M.; Rothard, Hermann; Boduch, Philippe

    2017-12-01

    We experimentally address in this paper the physicochemical effects induced by ionizing photons (energies from 6 to 2000 eV) and swift heavy ions (15.7 MeV 16O5+) in the icy mixture containing N2:CH4 (19:1) at 12 K and 19 K, respectively. The experiments simulate the effect of solar photons and X-rays, cosmic rays, and solar energetic particles (medium-mass ions) on the surface of icy bodies in the outer solar system, such as Triton, Titan, Pluto, and several other Kuiper Belt objects. The ice samples were analyzed by infrared spectroscopy (FTIR) at different fluences. From the energetic processing, the production of new molecules was observed. Among them, HCN, C2H4, C2H6, and N3 have the highest production yield. Molecular half-lives of the species of interest were calculated and extrapolated to the astrophysical environment. The effective destruction yield (in molecules/impact) of the parental species processed by the swift ions is up to six orders of magnitude higher than the value determined by employing X-rays. However, due to the differences between the fluxes of both ionizing radiation types in space, the half-lives of nitrogen and methane in the astrophysical scenarios addressed may have a huge variation. Photons dominate the chemical transformations at shorter distances from the Sun. Our results are a step toward a compilation of photochemical and radiolysis data that should allow the modeling of the abundance of astrophysical ices over long periods of time.

  1. Body composition assessment in infancy and early childhood: comparison of anthropometry with dual-energy X-ray absorptiometry in low-income group children from India.

    Science.gov (United States)

    Kulkarni, B; Mamidi, R S; Balakrishna, N; Radhakrishna, K V

    2014-06-01

    Anthropometry is a simple, inexpensive method of body composition assessment, but its validity has not been examined adequately in young children. The study therefore compared the body composition estimates using anthropometry with those using dual-energy X-ray absorptiometry (DXA) in infants and young children. Body composition estimates using anthropometry and DXA were assessed and compared at 6, 12 and 18 months in a cohort of 137 infants enrolled at birth. Fat mass (FM) and body fat percent (%BF) estimates by anthropometry were lower than those using DXA. Mean differences (DXA-skinfold thickness) in FM, fat free mass (FFM) and %BF were highest at 6 months (350 g, -226 g and 4%, respectively); the differences reduced with increase in age and were lowest at 18 months (46 g, 56 g and 0%, respectively). Bland-Altman analyses showed good agreement between the FM, FFM and %BF estimates by the two methods only at 18 months. Accretion of FM and FFM during follow-up, estimated by the two methods, was significantly different, with agreement between the methods seen only for increment in FFM from 6 to 12 months. Substantial differences were found in the body composition estimates by anthropometry compared with DXA and also in the longitudinally assessed tissue accretion patterns by the two methods. As the body composition patterns may be influenced by the method used for body composition assessment, results of studies assessing body composition by anthropometry during infancy should be interpreted with caution.

  2. Chest X-Ray

    Medline Plus

    Full Text Available ... Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us ... to consider the likelihood of benefit to your health. While a chest x-ray use a tiny ...

  3. Bone mineral density in the lumbar spine as determined by dual-energy X-ray absorptiometry. Comparison of whole-body scans and dedicated regional scans

    Energy Technology Data Exchange (ETDEWEB)

    Nysom, K. [Section for Pediatric Haematology and Oncology, Copenhagen Univ. Hospital (Denmark); Moelgaard, C.; Fleischer Michaelsen, K. [Research Dept. of Human Nutrition, Royal Veterinary and Agricultural Univ., Fredriksberg (Denmark)]|[Centre for Advanced Food Studies, Royal Veterinary and Agricultural Univ., Fredriksberg (Denmark)

    1998-11-01

    Purpose: To compare bone mineral in the lumbar spine as measured by either consecutive regional or whole-body dual-energy X-ray absorptiometry (DXA), and to develop models that predict regional results from whole-body results. Material and Methods: In 180 children and young adults, bone mineral in the lumbar spine was measured by a Hologic QDR-1000/W DXA scanner, using either whole-body software (which can give data for the lumbar spine subregion) or dedicated lumbar spine software. Data on 139 persons were used to compare the two methods and to develop models that predict the result of a regional scan from the result of a whole-body scan. Data on the remaining 41 persons were used to control these models. Results: Bone mineral content, bone area, and bone mineral areal density (BMD{sub A}) of the lumbar spine were measured significantly lower by whole-body scans than by regional scans (p<0.0001). The difference was larger for the lower values of bone area and BMD{sub A}. We developed models that predicted lumbar spine BMD{sub A} from whole-body results. When these models were controlled in another group, the mean error between the methods was non-significant and the error was unrelated to the BMD{sub A} value. However, the variance of the error was only minimally reduced. Conclusions: Lumbar spine bone mineral was measured significantly lower by whole-body DXA than by regional DXA. Based on local data, models were developed that removed the significant difference between the methods. (orig.)

  4. [Analysis of X-ray fluorescence spectroscopy and plasma mass spectrometry of the Guidong granite body and its implications to granite evolution].

    Science.gov (United States)

    Li, Hong-Wei; Chen, Guo-Neng; Peng, Zhuo-Lun

    2013-07-01

    The Guidong composite granite body (CGB) located in the north Guangdong Province consists of numerous rock bodies formed respectively in the early and late Jurassic and early Cretaceous. Analysis of the granites of different period with X-ray fluorescence spectroscopy and plasma mass spectrometry indicates: (1) From the top of a granite body downwards, the felsic components of rock decrease, while the mafic and sigmaREE, LREE/HREE, (La/Yb)N, as well as delta Eu value increase, suggesting the material differentiation in the in-situ melting of crustal rocks and crystallisation of magma; (2) From old to young of the different period granite-massifs in the Guidong CGB, the felsic compositions totally decrease, and the mafic components, sigmaEE, LREE/HREE, (La/Yb)N, and delta Eu value increase as well, implying multiple crustal melting (remelting) events in the Mesozoic in this area; and (3) Primitive mantle-normalized spider diagram for trace elements of Guidong CGB suggests high maturity of the crust involved in the in-situ melting.

  5. Regional body composition determined by dual-energy X-ray absorptiometry. Relation to training, sex hormones, and serum lipids in male long-distance runners.

    Science.gov (United States)

    Hetland, M L; Haarbo, J; Christiansen, C

    1998-04-01

    This study investigated the regional distribution of fatty and lean tissue in long-distance runners, and the relation to training, sex hormones, and serum lipids. One hundred and twenty lean men (22 elite, 86 recreational runners and 12 non-running controls) aged 32 +/- 8.1 years (mean +/- SD) participated. Body composition (adipose and lean tissue) was measured by dual-energy x-ray absorptiometry in the total body and in the abdomen, the arms and the legs. Regional and total body fat correlated inversely with the performance at an incremental treadmill exercise test (-0.61 fat percentage in the abdomen and in the legs was 42% and 36% lower in the elite runners in comparison with the non-running controls. Sex hormonal status and serum lipids were unrelated to training. After multiple regression analysis the most significant determinant of the fat percentage in the legs was the weekly distance run (partial r = -0.40, P testosterone index also contributed strongly (partial r = 0.39, P low amounts of fatty tissue in the abdomen and in the extremities, and the fat percentages in the abdomen and in the legs were associated with both the training intensity and androgenic activity. Since the abdominal fatty tissue is a significant risk factor for cardiovascular disease, running may have a positive impact on the long-term risk.

  6. Comparison of Body Composition Assessed by Dual-Energy X-Ray Absorptiometry and BMI in Current and Former U.S. Navy Service Members.

    Directory of Open Access Journals (Sweden)

    Heath G Gasier

    Full Text Available Little is known of the diagnostic accuracy of BMI in classifying obesity in active duty military personnel and those that previously served. Thus, the primary objectives were to determine the relationship between lean and fat mass, and body fat percentage (BF% with BMI, and assess the agreement between BMI and BF% in defining obesity.Body composition was measured by dual-energy X-ray absorptiometry in 462 males (20-91 years old who currently or previously served in the U.S. Navy. A BMI of ≥ 30 kg/m2 and a BF% ≥ 25% were used for obesity classification.The mean BMI (± SD and BF% were 28.8 ± 4.1 and 28.9 ± 6.6%, respectively, with BF% increasing with age. Lean mass, fat mass, and BF% were significantly correlated with BMI for all age groups. The exact agreement of obesity defined by BMI and BF% was fair (61%, however, 38% were misclassified by a BMI cut-off of 30 when obesity was defined by BF%.From this data we determined that there is a good correlation between body composition and BMI, and fair agreement between BMI and BF% in classifying obesity in a group of current and former U.S. Navy service members. However, as observed in the general population, a significant proportion of individuals with excess fat are misclassified by BMI cutoffs.

  7. Comparison of two bioelectrical impedance devices and dual-energy X-ray absorptiometry to evaluate body composition in heart failure.

    Science.gov (United States)

    Alves, F D; Souza, G C; Biolo, A; Clausell, N

    2014-12-01

    The utilisation of bioelectrical impedance analysis (BIA) in heart failure can be affected by many factors and its applicability remains controversial. The present study aimed to verify the adequacy of single-frequency BIA (SF-BIA) and multifrequency BIA (MF-BIA) compared to dual-energy x-ray absorptiometry (DEXA) for evaluating body composition in outpatients with heart failure. In this cross-sectional study, 55 patients with stable heart failure and left ventricle ejection fraction ≤45% were evaluated for fat mass percentage, fat mass and fat-free mass by DEXA and compared with the results obtained by SF-BIA (single frequency of 50 kHz) and MF-BIA (frequencies of 20 and 100 kHz). MF-BIA and DEXA gave similar mean values for fat mass percentage, fat mass and fat-free mass, whereas values from SF-BIA were significantly different from DEXA. Both SF-BIA and MF-BIA measures of body composition correlated strongly with DEXA (r > 0.8; P  0.05), except MF-BIA for fat-free mass. Compared with DEXA, MF-BIA showed better accuracy than SF-BIA, although both types of equipment showed wide limits of agreement. The BIA technique should be used with caution, and regression equations might be useful for correcting the observed variations, mainly in extreme values of body composition. © 2014 The British Dietetic Association Ltd.

  8. Sequential hemi-body radiotherapy in advanced multiple myeloma. [Side effects of indicated x-ray therapy

    Energy Technology Data Exchange (ETDEWEB)

    Jaffe, J.P.; Bosch, A.; Raich, P.C.

    1979-01-01

    Eleven patients with advanced multiple myeloma refractory to standard chemotherapy were treated with a regimen of sequential hemi-body radiotherapy consisting of 800 rad midplane in a single dose to each half. 9/10 patients experienced significant relief of skeletal pain and there were 5/11 objective tumor responses with one complete remission. Treatment-related morbidity was significant and consisted primarily of nausea and emesis, bone marrow suppression, and pneumonitis. This therapy is helpful in the management of advanced myeloma, and should be studied earlier in the course of the disease.

  9. Study of bioaccumulation and biotransformation by microanalytical X-ray techniques: investigation of distribution and speciation of Cu and Cr in the body of the plant-feeding nematode, Xiphinema vuittenezi

    Energy Technology Data Exchange (ETDEWEB)

    Sávoly, Zoltán; Záray, Gyula, E-mail: zaray@ludens.elte.hu

    2014-11-01

    method was the same as in the case of the elemental mapping. For Cu, the sample spectrum was fitted by the spectra of reference compounds, and Cu{sub 3}(PO{sub 4}){sub 2}, was found to be the main component, which harmonized with the results of the elemental distribution measurements. However, the role of S-containing ligands in Cu detoxification cannot be excluded, since the spectrum of Cu-cysteine complex was a minor component of the fit. It was also established that in the chromate treated nematodes a considerable part of Cr(VI) was reduced to Cr(III). - Highlights: • X-ray spectrometric measurements in the plant-feeding nematode, Xiphinema vuittenezi. • Differences in the uptake of Cr(III) and Cr(VI). • Distribution of Cr and Cu, correlation with distribution of essential elements, especially the P. • Cu speciation, important role of P-containing ligands in binding of Cu. • Significant reduction of Cr(VI) to Cr(III) in the body of the nematode.

  10. X-ray induced optical reflectivity

    Directory of Open Access Journals (Sweden)

    Stephen M. Durbin

    2012-12-01

    Full Text Available The change in optical reflectivity induced by intense x-ray pulses can now be used to study ultrafast many body responses in solids in the femtosecond time domain. X-ray absorption creates photoelectrons and core level holes subsequently filled by Auger or fluorescence processes, and these excitations ultimately add conduction and valence band carriers that perturb optical reflectivity. Optical absorption associated with band filling and band gap narrowing is shown to explain the basic features found in recent measurements on an insulator (silicon nitride, Si3N4, a semiconductor (gallium arsenide, GaAs, and a metal (gold, Au, obtained with ∼100 fs x-ray pulses at 500-2000 eV and probed with 800 nm laser pulses. In particular GaAs exhibits an abrupt drop in reflectivity, persisting only for a time comparable to the x-ray excitation pulse duration, consistent with prompt band gap narrowing.

  11. X-ray filter for x-ray powder diffraction

    Science.gov (United States)

    Sinsheimer, John Jay; Conley, Raymond P.; Bouet, Nathalie C. D.; Dooryhee, Eric; Ghose, Sanjit

    2018-01-23

    Technologies are described for apparatus, methods and systems effective for filtering. The filters may comprise a first plate. The first plate may include an x-ray absorbing material and walls defining first slits. The first slits may include arc shaped openings through the first plate. The walls of the first plate may be configured to absorb at least some of first x-rays when the first x-rays are incident on the x-ray absorbing material, and to output second x-rays. The filters may comprise a second plate spaced from the first plate. The second plate may include the x-ray absorbing material and walls defining second slits. The second slits may include arc shaped openings through the second plate. The walls of the second plate may be configured to absorb at least some of second x-rays and to output third x-rays.

  12. Relationship between Weight, Body Mass Index, and Bone Mineral Density in Men Referred for Dual-Energy X-Ray Absorptiometry Scan in Isfahan, Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Salamat

    2013-01-01

    Full Text Available Objective. Although several studies have investigated the association between body mass index (BMI and bone mineral density (BMD, the results are inconsistent. The aim of this study was to further investigate the relation between BMI, weight and BMD in an Iranian men population. Methods. A total of 230 men 50-79 years old were examined. All men underwent a standard BMD scans of hip (total hip, femoral neck, trochanter, and femoral shaft and lumbar vertebrae (L2-L4 using a Dual-Energy X-ray Absorptiometry (DXA scan and examination of body size. Participants were categorised in two BMI group: normal weight <25.0 kg/m2 and overweight and obese, BMI ≥ 25 kg/m2. Results. Compared to men with BMI ≥ 25, the age-adjusted odds ratio of osteopenia was 2.2 (95% CI 0.85, 5.93 and for osteoporosis was 4.4 (1.51, 12.87 for men with BMI < 25. It was noted that BMI and weight was associated with a high BMD, compatible with a diagnosis of osteoporosis. Conclusions. These data indicate that both BMI and weight are associated with BMD of hip and vertebrae and overweight and obesity decreased the risk for osteoporosis. The results of this study highlight the need for osteoporosis prevention strategies in elderly men as well as postmenopausal women.

  13. Comparison of dual-energy X-ray absorptiometry, air displacement plethysmography and bioelectrical impedance analysis for the assessment of body composition in morbidly obese women.

    Science.gov (United States)

    Bedogni, G; Agosti, F; De Col, A; Marazzi, N; Tagliaferri, A; Sartorio, A

    2013-11-01

    We evaluated the agreement of air displacement plethysmography (ADP) and bioelectrical impedance analysis (BIA) with dual-energy X-ray absorptiometry (DXA) for the assessment of percent fat mass (%FM) in morbidly obese women. Fifty-seven women aged 19-55 years and with a body mass index (BMI) ranging from 37.3 to 55.2 kg/m(2) were studied. Values of %FM were obtained directly from ADP and DXA, whereas for BIA we estimated fat-free mass (FFM) from an equation for morbidly obese subjects and calculated %FM as (weight-FFM)/weight. The mean (s.d.) difference between ADP and DXA for the assessment of %FM was -2.4% (3.3%) with limits of agreement (LOA) from -8.8% to 4.1%. The mean (s.d.) difference between BIA and DXA for the assessment of %FM was 1.7% (3.3%) with LOA from -4.9% to 8.2%. ADP-DXA and BIA-DXA are not interchangeable methods for the assessment of body composition in morbidly obese women.

  14. The validity of commonly used adipose tissue body composition equations relative to dual energy X-ray absorptiometry (DXA) in gaelic games players.

    Science.gov (United States)

    Doran, D A; Mc Geever, S; Collins, K D; Quinn, C; McElhone, R; Scott, M

    2014-02-01

    Dual-energy X-ray absorptiometry (DXA) and adipose tissue percentage estimates (AT%) derived from regression based skinfold equations were compared. 35 Gaelic games players [20.9 ± 1.7 years; 78.1 ± 8.6 kg; 179.5 ± 5.7 cm] underwent whole body fan beam DXA scans following a standardised protocol and assessment of skinfold thickness at 8 sites. Adipose tissue% from the sum of skinfolds and/or via body density were calculated for general and athlete specific equations (SKf-AT %). The relationship, i. e., proportional bias, fixed bias and random error (SEE) between DXA-AT % and AT % derived from the 6 skinfold equations were determined using least squares regression analysis. Skinfold AT% estimates were underestimated relative to DXA-AT % across all skinfold equations except that of Durnin and Wormersley [9] (D&W-∑(4AT %)) (16.7 ± 3.4 vs. 16.6 ± 4.0 %). All equations demonstrated 95 % prediction intervals ranges exceeding ~10 %. Each equation failed to predict AT% relative to DXA within an accepted ± 3.5 % anthropometric error rate. It is recommended that the conversion of absolute skinfold thickness to an AT % is avoided and that the skinfold equations assessed herein are not utilised in Gaelic games players. Alternate 'sum of skinfold' approaches should be considered. © Georg Thieme Verlag KG Stuttgart · New York.

  15. Comparison of gross body fat-water magnetic resonance imaging at 3 Tesla to dual-energy X-ray absorptiometry in obese women.

    Science.gov (United States)

    Silver, Heidi J; Niswender, Kevin D; Kullberg, Joel; Berglund, Johan; Johansson, Lars; Bruvold, Morten; Avison, Malcolm J; Welch, E Brian

    2013-04-01

    Improved understanding of how depot-specific adipose tissue mass predisposes to obesity-related comorbidities could yield new insights into the pathogenesis and treatment of obesity as well as metabolic benefits of weight loss. We hypothesized that three-dimensional (3D) contiguous "fat-water" MR imaging (FWMRI) covering the majority of a whole-body field of view (FOV) acquired at 3 Tesla (3T) and coupled with automated segmentation and quantification of amount, type, and distribution of adipose and lean soft tissue would show great promise in body composition methodology. Precision of adipose and lean soft tissue measurements in body and trunk regions were assessed for 3T FWMRI and compared to dual-energy X-ray absorptiometry (DXA). Anthropometric, FWMRI, and DXA measurements were obtained in 12 women with BMI 30-39.9 kg/m(2) . Test-retest results found coefficients of variation (CV) for FWMRI that were all under 3%: gross body adipose tissue (GBAT) 0.80%, total trunk adipose tissue (TTAT) 2.08%, visceral adipose tissue (VAT) 2.62%, subcutaneous adipose tissue (SAT) 2.11%, gross body lean soft tissue (GBLST) 0.60%, and total trunk lean soft tissue (TTLST) 2.43%. Concordance correlation coefficients between FWMRI and DXA were 0.978, 0.802, 0.629, and 0.400 for GBAT, TTAT, GBLST, and TTLST, respectively. While Bland-Altman plots demonstrated agreement between FWMRI and DXA for GBAT and TTAT, a negative bias existed for GBLST and TTLST measurements. Differences may be explained by the FWMRI FOV length and potential for DXA to overestimate lean soft tissue. While more development is necessary, the described 3T FWMRI method combined with fully-automated segmentation is fast (<30-min total scan and post-processing time), noninvasive, repeatable, and cost-effective. Copyright © 2012 The Obesity Society.

  16. Changes in body composition during weight loss in obese subjects in the NUGENOB study: comparison of bioelectrical impedance vs. dual-energy X-ray absorptiometry.

    Science.gov (United States)

    Verdich, C; Barbe, P; Petersen, M; Grau, K; Ward, L; Macdonald, I; Sørensen, T I A; Oppert, J-M

    2011-06-01

    We studied the accuracy of bioelectrical impedance analysis (BIA) to assess changes in body composition during moderate weight loss in obese subjects. Estimates of changes in fat mass (FM) and fat-free mass (FFM) by BIA were compared with those by dual-energy X-ray absorptiometry (DXA) as the reference method during a 10-week standardized weight-loss intervention. In obese women (age: 20-50 years, mean BMI: 33.8 kg/m(2)) participating in a European multicentre trial (nutrient-gene interactions in human obesity [NUGENOB]), body composition was assessed by BIA (Bodystat QuadScan 4000) and DXA (Lunar DPX-IQ at two centres, Hologic QDR 2000 at another centre) at baseline (n=131) and at week 10 (n=105) after a mean weight loss of -5.7 kg. At baseline, BIA significantly overestimated FFM and underestimated FM (by 1-3 kg on average) compared with DXA, and the limits of agreement were wide (mean ± 7-8.5 kg). For body-composition changes, although biases were generally non-significant, the limits of agreement were also wide (mean ± 3.7-4.6 kg). An FFM prediction equation for BIA data was developed in subjects scanned with Lunar instruments and cross-validated in an independent sample of 31 obese women undergoing similar weight loss. However, no major improvement in limits of agreement was found. During moderate diet-induced weight loss, the use of BIA leads to estimates of changes in body composition at the individual level that can differ substantially from those assessed by DXA, indicating that BIA and DXA cannot be used interchangeably. However, BIA in this context may be used for assessing changes in body composition at group level. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  17. Body composition analysis by leg-to-leg bioelectrical impedance and dual-energy X-ray absorptiometry in non-obese and obese individuals.

    Science.gov (United States)

    Boneva-Asiova, Z; Boyanov, M A

    2008-11-01

    The aim of this study is to compare total weight, % body fat (% BF), fat mass (FM) and fat-free mass (FFM) measured by bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA). This cross-sectional study included 159 women (mean age: 49.1 +/- 10.0 years) and 124 men (mean age: 51.4 +/- 8.0 years) subdivided according to sex and body mass index (BMI): BMI or = 35 kg/m(2) (40 women and 30 men). Bioelectrical impedance was performed in the fasting state on a Tanita TBF-215 leg-to-leg analyser (Tanita, Tokyo, Japan). Whole-body DXA scans were performed on a Hologic QDR 4500 A bone densitometer (Hologic, Bedford, MA, USA). Total weight, % BF, FM and FFM were tested for intermethod differences. Linear regression and correlation analysis was performed. Limits of agreement and Bland-Altman plots were built. DXA-derived body composition parameters were not significantly different from BIA estimates and were highly correlated (e.g. for FFM, r = 0.82-0.95). In lean individuals, BIA tended to produce lower values for FM and % BF and higher ones for FFM in comparison with DXA. This trend was reversed at BMI > 35 kg/m(2). The correlations decreased with increasing BMI. The limits of agreement were much better in men than in women and increased with increasing BMI in both sexes. Compared with DXA, the leg-to-leg Tanita TBF-215 analyser accurately assessed body composition in a heterogeneous group of both sexes. In the very obese women (BMI > 35 kg/m(2)), BIA measurements should be viewed with caution.

  18. Comparison of the Lunar DPX-L and Prodigy dual-energy X-ray absorptiometers for assessing total and regional body composition.

    Science.gov (United States)

    Huffman, Derek M; Landy, Niamh M; Potter, Eva; Nagy, Tim R; Gower, Barbara A

    2005-01-01

    The purpose of this study was to assess the agreement of the Lunar DPX-L with the newer Prodigy dual-energy X-ray absorptiometer (DXA) for determining total-body and regional (arms, legs, trunk) bone mineral density (BMD), bone mineral content (BMC), fat mass (FM), lean tissue mass (LTM), total body mass (BM) and percent fat. A total of 106 apparently healthy males (n=34) and females (n=72) between the ages of 8-72 years were scanned consecutively on the DPX-L (software version 1.35) and Prodigy DXA (enCORE v. 3.6 software). Paired t-tests indicated significantly higher measures by Prodigy for BM (percent difference= 1.1%) and total-body BMD (2.2%), BMC (2.9%), FM (3.5%), and percent fat (2.8%; PProdigy relative to DPX-L. The percent difference was most pronounced for FM in the arms (14.2%) and trunk (8.5%), BMD in the legs (4.9%), LTM in arms (5.6%), and BMC in the trunk (5.9%); but all total-body and regional measures were strongly and significantly correlated (PProdigy overestimated DPX-L for BM (r=0.343; PProdigy-DPX-L) versus mean ((Prodigy+DPX-L)/2). Regionally, Prodigy overestimated DPX-L for BMD in the legs, BMC in the legs and trunk, and FM in the arms at higher values (PProdigy relative to DPX-L at higher values (P<0.001), and no regional bias was observed for LTM. In conclusion, we recommend that correction equations be used for comparing BM, total-body BMD and BMC, and regionally for BMD in the legs, BMC in the legs and trunk, and FM in the arms and legs. The use of correction equations for other estimates is not required for making direct comparisons.

  19. X-ray refractometer

    International Nuclear Information System (INIS)

    Tur'yanskij, A.G.; Pirshin, I.V.

    2001-01-01

    Paper introduces a new circuit of X-ray refractometer to study angular and spectral features of refracted radiation within hard X-ray range. Refractometer incorporates two goniometers, two crystal-analyzers and three radiation detectors. The maximum distance between radiation source focal point and a receiving slit of the second goniometer is equal to 1.4 m. For the first time one obtained refraction patterns of fine-film specimens including C/Si stressed structure. Paper describes a new technique of refractometry via specimen oscillation at fixed position of a detecting device. Paper presents the measurement results of oscillation refraction patterns for specimens of melted quartz and ZnSe single crystal [ru

  20. Associations Between Sedentary Time, Physical Activity, and Dual-Energy X-ray Absorptiometry Measures of Total Body, Android, and Gynoid Fat Mass in Children.

    Science.gov (United States)

    McCormack, Lacey; Meendering, Jessica; Specker, Bonny; Binkley, Teresa

    2016-01-01

    Negative health outcomes are associated with excess body fat, low levels of physical activity (PA), and high sedentary time (ST). Relationships between PA, ST, and body fat distribution, including android and gynoid fat, assessed using dual-energy X-ray absorptiometry (DXA) have not been measured in children. The purpose of this study was to test associations between levels of activity and body composition in children and to evaluate if levels of activity predict body composition by DXA and by body mass index percentile in a similar manner. PA, ST, and body composition from 87 children (8.8-11.8 yr, grades 3-5, 44 boys) were used to test the association among study variables. Accelerometers measured PA and ST. Body composition measured by DXA included bone mineral content (BMC) and fat and lean mass of the total body (TB, less head), android, and gynoid regions. ST (range: 409-685 min/wk) was positively associated with TB percent fat (0.03, 95% confidence interval [CI]: 0.00-0.05) and android fat mass (1.5 g, 95% CI: 0.4-3.0), and inversely associated with the lean mass of the TB (-10.7 g, 95% CI: -20.8 to -0.63) and gynoid regions (-2.2 g, 95% CI: -4.3 to -0.2), and with BMC (-0.43 g, 95% CI: 0.77-0.09). Moderate-to-vigorous PA was associated with lower TB (-53 g, 95% CI: -87 to -18), android (-5 g, 95% CI: -8 to -2]), and gynoid fat (-6 g, 95% CI: -11 to -0.5). Vigorous activity results were similar. Light PA was associated with increased TB (17.1 g, 95% CI: 3.0-31.3) and gynoid lean mass (3.9 g, 95% CI: 1.0-6.8) and BMC (0.59 g, 95% CI: 0.10-1.07). In boys, there were significant associations between activity and DXA percent body fat measures that were not found with the body mass index percentile. Objective measures of PA were inversely associated with TB, android, and gynoid fat, whereas ST was directly associated with TB percent fat and, in particular, android fat. Activity levels predict body composition measures by DXA and, in

  1. X-ray diffraction

    International Nuclear Information System (INIS)

    Einstein, J.R.; Wei, C.H.

    1982-01-01

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

  2. X-ray apparatus

    International Nuclear Information System (INIS)

    Tomita, Chuji.

    1980-01-01

    A principal object of the present invention is to provide an X-ray apparatus which is such that the distance between the surface of the patient's table and the floor on which the apparatus is installed is sufficiently small in the horizontal position of the patient's table of the roentgenographical pedestal and that the rotation of the pedestal from the horizontal position to a tilted position and further to the vertical position of the table can be carried out smoothly. (auth)

  3. Assessment of PCXMC for patients with different body size in chest and abdominal x ray examinations: a Monte Carlo simulation study

    Science.gov (United States)

    Borrego, David; Lowe, Erin M.; Kitahara, Cari M.; Lee, Choonsik

    2018-03-01

    A PC Program for x ray Monte Carlo (PCXMC) has been used to calculate organ doses in patient dosimetry and for the exposure assessment in epidemiological studies of radiogenic health related risks. This study compared the dosimetry from using the built-in stylized phantoms in the PCXMC to that of a newer hybrid phantom library with improved anatomical realism. We simulated chest and abdominal x ray projections for 146 unique body size computational phantoms, 77 males and 69 females, with different combinations of height (125–180 cm) and weight (20–140 kg) using the built-in stylized phantoms in the PCXMC version 2.0.1.4 and the hybrid phantom library using the Monte Carlo N-particle eXtended transport code 2.7 (MCNPX). Unfortunately, it was not possible to incorporate the hybrid phantom library into the PCXMC. We compared 14 organ doses, including dose to the active bone marrow, to evaluate differences between the built-in stylized phantoms in the PCXMC and the hybrid phantoms (Cristy and Eckerman 1987 Technical Report ORNL/TM-8381/V1, Oak Ridge National Laboratory, Eckerman and Ryman 1993 Technical Report 12 Oak Ridge, TN, Geyer et al 2014 Phys. Med. Biol. 59 5225–42). On average, organ doses calculated using the built-in stylized phantoms in the PCXMC were greater when compared to the hybrid phantoms. This is most prominent in AP abdominal exams by an average factor of 2.4-, 2.8-, and 2.8-fold for the 10-year-old, 15-year-old, and adult phantoms, respectively. For chest exams, organ doses are greater by an average factor of 1.1-, 1.4-, and 1.2-fold for the 10-year-old, 15-year-old, and adult phantoms, respectively. The PCXMX, due to its ease of use, is often selected to support dosimetry in epidemiological studies; however, it uses simplified models of the human anatomy that fail to account for variations in body morphometry for increasing weight. For epidemiological studies that use PCXMC dosimetry, associations between radiation-related disease risks

  4. Producing x-rays

    International Nuclear Information System (INIS)

    Mallozzi, P.J.; Epstein, H.M.; Jung, R.G.; Applebaum, D.C.; Fairand, B.P.; Gallagher, W.J.

    1977-01-01

    A method of producing x-rays by directing radiant energy from a laser onto a target is described. Conversion efficiency of at least about 3 percent is obtained by providing the radiant energy in a low-power precursor pulse of approximately uniform effective intensity focused onto the surface of the target for about 1 to 30 nanoseconds so as to generate an expanding unconfined coronal plasma having less than normal solid density throughout and comprising a low-density (underdense) region wherein the plasma frequency is less than the laser radiation frequency and a higher-density (overdense) region wherein the plasma frequency is greater than the laser radiation frequency and, about 1 to 30 nanoseconds after the precursor pulse strikes the target, a higher-power main pulse focused onto the plasma for about 10 -3 to 30 nanoseconds and having such power density and total energy that the radiant energy is absorbed in the underdense region and conducted into the overdense region to heat it and thus to produce x-rays therefrom with the plasma remaining substantially below normal solid density and thus facilitating the substantial emission of x-rays in the form of spectral lines arising from nonequilibrium ionization states

  5. Bone X-Ray (Radiography)

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    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... position possible that still ensures x-ray image quality. top of page Who interprets the results and ...

  6. Bone X-Ray (Radiography)

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    Full Text Available ... tissue shows up in shades of gray and air appears black. Until recently, x-ray images were ... position possible that still ensures x-ray image quality. top of page Who interprets the results and ...

  7. Bone X-Ray (Radiography)

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    Full Text Available ... Videos About Us News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x- ... x-ray machine is a compact apparatus that can be taken to the patient in a hospital ...

  8. Bone X-Ray (Radiography)

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    Full Text Available ... shades of gray and air appears black. Until recently, x-ray images were maintained on large film ... assist you in finding the most comfortable position possible that still ensures x-ray image quality. top ...

  9. Bone X-Ray (Radiography)

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    Full Text Available ... position possible that still ensures x-ray image quality. top of page Who interprets the results and ... ray examination. X-rays usually have no side effects in the typical diagnostic range for this exam. ...

  10. Bone X-Ray (Radiography)

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    Full Text Available ... can be taken to the patient in a hospital bed or the emergency room. The x-ray ... position possible that still ensures x-ray image quality. top of page Who interprets the results and ...

  11. Bone X-Ray (Radiography)

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

  12. X-ray detector array

    International Nuclear Information System (INIS)

    Houston, J.M.

    1980-01-01

    The object of the invention (an ionization chamber X-ray detector array for use with high speed computerised tomographic imaging apparatus) is to reduce the time required to produce a tomographic image. The detector array described determines the distribution of X-ray intensities in one or more flat, coplanar X-ray beams. It comprises three flat anode sheets parallel to the X-ray beam, a plurality of rod-like cathodes between the anodes, a detector gas between the electrodes and a means for applying a potential between the electrodes. Each of the X-ray sources is collimated to give a narrow, planar section of X-ray photons. Sets of X-ray sources in the array are pulsed simultaneously to obtain X-ray transmission data for tomographic image reconstruction. (U.K.)

  13. Bone X-Ray (Radiography)

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

  14. Bone X-Ray (Radiography)

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    Full Text Available ... patient. top of page How does the procedure work? X-rays are a form of radiation like ... Safety page for more information about radiation dose. Women should always inform their physician or x-ray ...

  15. Bone X-Ray (Radiography)

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    Full Text Available ... standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures ...

  16. Bone X-Ray (Radiography)

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

  17. Bone X-Ray (Radiography)

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    Full Text Available ... tissues around or in bones. top of page How should I prepare? Most bone x-rays require ... is placed beneath the patient. top of page How does the procedure work? X-rays are a ...

  18. Bone X-Ray (Radiography)

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

  19. Soft X-ray Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Seely, John

    1999-05-20

    The contents of this report cover the following: (1) design of the soft x-ray telescope; (2) fabrication and characterization of the soft x-ray telescope; and (3) experimental implementation at the OMEGA laser facility.

  20. Bone X-Ray (Radiography)

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    Full Text Available ... that might interfere with the x-ray images. Women should always inform their physician and x-ray technologist if there is any possibility that they are pregnant. Many imaging tests are not performed during pregnancy ...

  1. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... of page What are some common uses of the procedure? A bone x-ray is used to: ... and x-rays. top of page What does the equipment look like? The equipment typically used for ...

  2. A Test Facility For Astronomical X-Ray Optics

    DEFF Research Database (Denmark)

    Lewis, R. A.; Bordas, J.; Christensen, Finn Erland

    1989-01-01

    Grazing incidence x-ray optics for x-ray astronomical applications are used outside the earths atmosphere. These devices require a large collection aperture and the imaging of an x-ray source which is essentially placed at infinity. The ideal testing system for these optical elements has...... to approximate that encountered under working conditions, however the testing of these optical elements is notoriously difficult with conventional x-ray generators. Synchrotron Radiation (SR) sources are sufficiently brilliant to produce a nearly perfect parallel beam over a large area whilst still retaining...... a flux considerably higher than that available from conventional x-ray generators. A facility designed for the testing of x-ray optics, particularly in connection with x-ray telescopes is described below. It is proposed that this facility will be accommodated at the Synchrotron Radiation Source...

  3. Comparison of segmental multifrequency bioelectrical impedance analysis with dual-energy X-ray absorptiometry for the assessment of body composition in a community-dwelling older population.

    Science.gov (United States)

    Kim, Miji; Shinkai, Shoji; Murayama, Hiroshi; Mori, Seijiro

    2015-08-01

    The purpose of the present study was to examine the agreement of segmental multifrequency bioelectrical impedance analysis (SMF-BIA) for the assessment of whole-body and appendicular fat mass (FM) and lean soft tissue mass (LSTM) compared with dual-energy X-ray absorptiometry (DXA) in a community-dwelling Japanese older population. The study population included 551 community-dwelling Japanese older adults (241 men and 310 women) aged between 65 and 87 years. Agreement between SMF-BIA and DXA for whole-body and appendicular body composition was assessed using simple linear regression and Bland-Altman analysis. High coefficients of determination (R(2)) were observed for whole-body FM (R(2) = 0.91, standard error of estimate [SEE] = 1.4 kg in men and R(2) = 0.94, SEE = 1.2 kg in women) between SMF-BIA and DXA. The R(2) coefficient for whole-body LSTM was higher in men (R(2) = 0.88, SEE = 1.9 kg) than in women (R(2) = 0.83, SEE = 1.5 kg). There was systematic bias with overestimation of whole-body FM and underestimation of whole-body LSTM by SMF-BIA. Proportional bias was noted for measurement of whole-body FM and LSTM in both men and women, but there was no proportional bias between the two methods for measurement of appendicular LSTM (r = 0.05, P = 0.428 and r = -0.10, P = 0.070 for men and women, respectively). SMF-BIA is a good alternative for estimating the whole-body and appendicular FM and LSTM in a community-dwelling Japanese older population, although it overestimated FM and underestimated LSTM when validated against DXA. © 2014 Japan Geriatrics Society.

  4. Body mass index versus dual energy x-ray absorptiometry-derived indexes: predictors of cardiovascular and diabetic disease risk factors.

    Science.gov (United States)

    Sharp, Dan S; Andrew, Michael E; Burchfiel, Cecil M; Violanti, John M; Wactawski-Wende, Jean

    2012-01-01

    The body mass index (BMI), a ratio of weight/height(2) , dominates estimation of adiposity in population studies. BMI, however, does not distinguish among fat, muscle, or bone mass. Accordingly, its usage to assess and manage obesity in the population is limited. This study compares the use of BMI with direct measures of fat- and lean-mass to predict established cardiovascular and diabetes risk factors: blood pressure, lipids, and glucose. The entire Buffalo Police Department was the object of recruitment to a baseline study of physiological and psychological stress. Four hundred nine officers constitute the sample for this analysis. Regression methods focusing on explained variance in blood pressure, high density lipoprotein (HDL) cholesterol, and blood glucose compare the use of BMI to that of fat- and lean-mass indexes derived from dual energy X-ray absorptiometry (DEXA). DEXA indexes explain 1.6%-3.3% (P mass drives the association for blood pressure, trunk lean mass for HDL cholesterol, and both for blood glucose. High degrees of multicollinearity complicate interpretation of predictive models jointly containing BMI and DEXA indexes. In police officers, DEXA indexes are better predictors of cardiovascular disease and diabetes risk factors. However, populations with different distributions of fitness, diet, and health conditions may demonstrate differentfeatures. In contrast to BMI, DEXA-derived measurements suggest avenues to explore metabolic processes, which relate to an index's underlying association with risk and may suggest more effective intervention strategies. Copyright © 2012 Wiley Periodicals, Inc.

  5. Energy-dispersive x-Ray Analysis of Phosphorus, Potassium, Magnesium, and Calcium in Globoid Crystals in Protein Bodies from Different Regions of Cucurbita maxima Embryos 1

    Science.gov (United States)

    Lott, John N. A.; Greenwood, John S.; Vollmer, Catherine M.; Buttrose, Mark S.

    1978-01-01

    The seeds of Cucurbita maxima contain protein bodies with electrondense globoid crystals. Because of their density globoid crystals are ideal material for energy-dispersive x-ray (EDX) analysis studies of elemental composition. Fixation trials were carried out to test globoid crystal extraction during glutaraldehyde fixation, water washing, and ethanol dehydration. Glutaraldehyde fixation without subsequent washing or dehydration alone produced no significant changes in elemental composition of cotyledon globoid crystals. If glutaraldehyde fixation was followed by water washes or ethanol dehydration there was some loss of the major globoid crystal elements but the relative percentages of the elements P, K, Ca, and Mg remained relatively unchanged. In this paper results of a study of the P, K, Mg, and Ca content of globoid crystals in different tissues of squash embryos are presented. The globoid crystals in the radicle were found to be the least dense in the embryo. Globoid crystals from all embryo regions contained P, K, and Mg. In the various embryo regions P and Mg maintained relatively constant proportions of the globoid crystal composition while K and Ca varied. Of particular significance is the distribution of Ca which is generally an immobile element. Calcium was found in highest amounts in the globoid crystals of the radicle and stem regions while globoid crystals in much of the cotyledon contained little, if any, Ca. The Ca storage thus seems to be spatially arranged in a manner that would aid early growth of the root-shoot axis. PMID:16660439

  6. Precision and accuracy of measurements of whole-body bone mineral: comparisons between Hologic, Lunar and Norland dual-energy X-ray absorptiometers.

    Science.gov (United States)

    Tothill, P; Avenell, A; Reid, D M

    1994-12-01

    Measurements of whole-body bone mineral made by Hologic, Lunar and Norland dual-energy X-ray absorptiometers have been compared. It was found that in each case the results were changed by new software protocols introduced by the manufacturers during the course of the study. With a moderately anthropomorphic model, the later software corrected some anomalies of regional bone mineral content (BMC) observed earlier. There was some slight dependence of total BMC on thickness and fat proportion and up to 15% difference between instruments. Measurements on volunteers showed good precision, but there were differences between instruments made by different manufacturers. There were high correlations, but the slopes of regression lines suggested differences of calibration of up to 8%; the standard errors of the estimates were 110 to 190 g. with maximum deviations from regression of 17%. There were regional disparities in BMC, particularly in the trunk, which arise (in part at least) from the imposition of a higher bone threshold by Hologic. From the pattern of results it was concluded that different assumptions were made by the manufacturers, particularly concerning the fat distribution model, which preclude the interchangeability of results from different instruments.

  7. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... used for bone x-rays consists of an x-ray tube suspended over a table on which the patient ... a hospital bed or the emergency room. The x-ray tube is connected to a flexible arm that is ...

  8. X-ray Crystallography Facility

    Science.gov (United States)

    2000-01-01

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

  9. Bone X-Ray (Radiography)

    Medline Plus

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

  10. Tunable X-ray source

    Science.gov (United States)

    Boyce, James R [Williamsburg, VA

    2011-02-08

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

  11. X-Ray Exam: Ankle

    Science.gov (United States)

    ... for Educators Search English Español X-Ray Exam: Ankle KidsHealth / For Parents / X-Ray Exam: Ankle What's in this article? What It Is Why ... You Have Questions Print What It Is An ankle X-ray is a safe and painless test ...

  12. Total body carbon and oxygen masses: evaluation of dual-energy x-ray absorptiometry estimation by in vivo neutron activation analysis

    Science.gov (United States)

    Wang, ZiMian; Pierson, Richard N., Jr.

    2010-10-01

    Oxygen and carbon are the first and second abundant elements, respectively, in the human body by mass. Although many physiological and pathological processes are accompanied with alteration of total body oxygen (TBO) and carbon (TBC) masses, in vivo measurements of the two elements are limited. Up to now, almost all available information of TBC and TBO is based on in vivo neutron activation (IVNA) analysis which is very expensive and involves moderate radiation exposure. The aim of the present study was to develop and evaluate an alternative strategy for TBC and TBO estimation. Mechanistic models were derived for predicting TBC and TBO masses from dual-energy x-ray absorptiometry (DXA) and total body water (TBW). Twenty-eight adult subjects were studied. IVNA-measured TBC and TBO masses were used as the criterion. TBC masses predicted by DXA-alone and by DXA-TBW models were 20.8 ± 7.1 kg and 20.6 ± 6.8 kg, respectively, close to the IVNA-measured value (19.5 ± 6.3 kg). There were strong correlations (both with r > 0.95, P 0.97, P < 0.001) were strong between the predicted and measured TBO masses. Bland-Altman analysis validated the applicability of DXA-based models to predict TBC and TBO masses. As both DXA and TBW dilutions are widely available, low-risk, low-cost techniques, the present study provides a safe and practical method for estimating elemental composition in vivo.

  13. X-ray diffraction

    International Nuclear Information System (INIS)

    Vries, J.L. de.

    1976-01-01

    The seventh edition of Philips' Review of literature on X-ray diffraction begins with a list of conference proceedings on the subject, organised by the Philips' organisation at regular intervals in various European countries. This is followed by a list of bulletins. The bibliography is divided according to the equipment (cameras, diffractometers, monochromators) and its applications. The applications are subdivided into sections for high/low temperature and pressure, effects due to the equipment, small angle scattering and a part for stress, texture and phase analyses of metals and quantitative analysis of minerals

  14. Obstetric X-rays

    International Nuclear Information System (INIS)

    Mwachi, M.K.

    2006-01-01

    Radiography of the pelvis should never be taken to diagnose early pregnancy, because of potential hazards of radiation damage to the growing foetus. the only indication occurs in the last week of pregnancy (37 weeks). Obstetric X-ray will help you answer like confirmation of malposition,multiple pregnancies; fetal abnormalities e.g. hydrocephalus, foetal disposition. The choice of radiographic projection will help give foetal presentation, disposition as well as foetal maturity. The search pattern helps you determine maternal and spine deformity, foetal spine and head , foetal presentation and any other anomalies

  15. Miniature X-Ray Tubes

    Science.gov (United States)

    Bearman, Gregory H.

    1995-01-01

    Miniature x-ray tubes proposed for use in portable instruments used to analyze minerals. Electrons from field emitter (instead of thermionic emitter) accelerated to target to generate x-rays. Fabricated from silicon wafers, micromachined field emitters (MFEs) not subject to breakage or restrictions on lifetimes, and tolerate vacuums that filaments cannot. Miniature x-ray tubes very robust, immune to shock and vibration, and permanently sealed with getter for continued pumping. Combined with solid-state x-ray detectors for analysis of x-ray fluorescence.

  16. National Health and Nutrition Examination Survey whole-body dual-energy X-ray absorptiometry reference data for GE Lunar systems.

    Science.gov (United States)

    Fan, Bo; Shepherd, John A; Levine, Michael A; Steinberg, Dee; Wacker, Wynn; Barden, Howard S; Ergun, David; Wu, Xin P

    2014-01-01

    The National Health and Nutrition Examination Survey (NHANES 1999-2004) includes adult and pediatric comparisons for total body bone and body composition results. Because dual-energy x-ray absorptiometry (DXA) measurements from different manufacturers are not standardized, NHANES reference values currently are applicable only to a single make and model of Hologic DXA system. The purpose of this study was to derive body composition reference curves for GE Healthcare Lunar DXA systems. Published values from the NHANES 1999-2004 survey were acquired from the Centers for Disease Control and Prevention website. Using previously reported cross-calibration equations between Hologic and GE-Lunar, we converted the total body and regional bone and soft-tissue measurements from NHANES 1999-2004 to GE-Lunar values. The LMS (LmsChartMaker Pro Version 3.5) curve fitting method was used to generate GE-Lunar reference curves. Separate curves were generated for each sex and ethnicity. The reference curves were also divided into pediatric (≤20 years old) and adult (>20 years old) groups. Adult reference curves were derived as a function of age. Additional relationships of pediatric DXA values were derived as a function of height, lean mass, and bone area. Robustness was tested between Hologic and GE-Lunar Z-score values. The NHANES 1999-2004 survey included a sample of 20,672 participants' (9630 female) DXA scans. A total of 8056 participants were younger than 20 yr and were included in the pediatric reference data set. Participants enrolled in the study who weighed more than 136 kg (over scanner table limit) were excluded. The average Z-scores comparing the new GE-Lunar reference curves are close to zero, and the standard deviation of the Z-scores are close to one for all variables. As expected, all measurements on the GE-Lunar reference curves for participants younger than 20 yr increase monotonically with age. In the adult population, most of the curves are constant at younger

  17. Test facility for astronomical x-ray optics

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Lewis, Robert A.; Bordas, J.

    1990-01-01

    Grazing incidence x-ray optics for x-ray astronomical applications are used outside the earth's atmosphere. These devices require a large collection aperture and the imaging of an x-ray source that is essentially placed at infinity. The ideal testing system for these optical elements has to appro......Grazing incidence x-ray optics for x-ray astronomical applications are used outside the earth's atmosphere. These devices require a large collection aperture and the imaging of an x-ray source that is essentially placed at infinity. The ideal testing system for these optical elements has...... to approximate that encountered under working conditions; however, the testing of these optical elements is notoriously difficult with conventional x-ray generators. Synchrotron radiation (SR) sources are sufficiently brilliant to produce a nearly perfect parallel beam over a large area while still retaining...... a flux considerably higher than that available from conventional x-ray generators. A facility designed for the testing of x-ray optics, particularly in connection with x-ray telescopes, is described. It is proposed that this facility will be accommodated at the Synchrotron Radiation Source...

  18. Percentage of body fat assessment using bioelectrical impedance analysis and dual-energy X-ray absorptiometry in a weight loss program for obese or overweight Chinese adults.

    Directory of Open Access Journals (Sweden)

    Yi-Chun Li

    Full Text Available The current study aimed to compare the estimates of body fat percentage (%BF by performing bioelectrical impedance analysis (BIA and dual energy X-ray absorptiometry (DXA in a sample of obese or overweight Chinese adults who participated in a weight-loss randomized control trial stratified by gender to determine whether or not BIA is a valid measurement tool. Among 189 adults [73 males, 116 females; age = 41 to 74 years; mean body mass index (BMI = 27.3 kg/m(2], assessments of %BF at the baseline and six months from the baseline were conducted by performing BIA and DXA. Bland-Altman analyses and multiple regression analyses were used to assess the relationships between %BFBIA and %BFDXA. Compared with DXA, BIA underestimated %BF [in males: 4.6, -2.4 to 11.7 (mean biases, 95% limit of agreement at the baseline, 1.4, -7.4 to 10.2 at the endpoint, and 3.2, -4.8 to 11.3 in changes; in females: 5.1, -2.4 to 12.7; 2.2, -6.1 to 10.4; and 3.0, -4.8 to 10.7, respectively]. For males and females, %BFDXA proved to be a significant predictor of the difference between DXA and BIA at the baseline, the endpoint, and in changes when BMI and age were considered (in males: p<0.01 and R (2 = 23.1%, 24.1%, 20.7%, respectively; for females: p<0.001 and R (2 = 40.4%, 48.8%, 25.4%, respectively. The current study suggests that BIA provides a relatively accurate prediction of %BF in individuals with normal weight, overweight, or obesity after the end of weight-loss program, but less accurate prediction of %BF in obese individuals at baseline or weight change during the weight-loss intervention program.

  19. Percentage of body fat assessment using bioelectrical impedance analysis and dual-energy X-ray absorptiometry in a weight loss program for obese or overweight Chinese adults.

    Science.gov (United States)

    Li, Yi-Chun; Li, Chia-Ing; Lin, Wen-Yuan; Liu, Chiu-Shong; Hsu, Hua-Shui; Lee, Cheng-Chun; Chen, Fei-Na; Li, Tsai-Chung; Lin, Cheng-Chieh

    2013-01-01

    The current study aimed to compare the estimates of body fat percentage (%BF) by performing bioelectrical impedance analysis (BIA) and dual energy X-ray absorptiometry (DXA) in a sample of obese or overweight Chinese adults who participated in a weight-loss randomized control trial stratified by gender to determine whether or not BIA is a valid measurement tool. Among 189 adults [73 males, 116 females; age = 41 to 74 years; mean body mass index (BMI) = 27.3 kg/m(2)], assessments of %BF at the baseline and six months from the baseline were conducted by performing BIA and DXA. Bland-Altman analyses and multiple regression analyses were used to assess the relationships between %BFBIA and %BFDXA. Compared with DXA, BIA underestimated %BF [in males: 4.6, -2.4 to 11.7 (mean biases, 95% limit of agreement) at the baseline, 1.4, -7.4 to 10.2 at the endpoint, and 3.2, -4.8 to 11.3 in changes; in females: 5.1, -2.4 to 12.7; 2.2, -6.1 to 10.4; and 3.0, -4.8 to 10.7, respectively]. For males and females, %BFDXA proved to be a significant predictor of the difference between DXA and BIA at the baseline, the endpoint, and in changes when BMI and age were considered (in males: pobesity after the end of weight-loss program, but less accurate prediction of %BF in obese individuals at baseline or weight change during the weight-loss intervention program.

  20. The evaluation of consistency between body composition assessments in pediatric population using pencil beam and fan beam dual-energy x-ray absorptiometers.

    Science.gov (United States)

    Pludowski, Pawel; Jaworski, Maciej; Matusik, Halina; Kobylinska, Maria; Klimek, Paulina; Lorenc, Roman S

    2010-01-01

    The replacement of the old dual-energy X-ray absorptiometry system with a novel one should be preceded by a cross-calibration procedure. Therefore, the study was aimed at investigating the consistency of bone and body composition measures performed in pediatric population using pencil beam (DPX-L; GE Healthcare, GE Healthcare, Madison, WI) and fan beam (Prodigy; GE Healthcare, GE Healthcare, Madison, WI) densitometers. The study group consisted of 212 healthy children aged 4-18yr. Total body (TB) and lumbar spine (S) (L2-L4) measurements were performed using DPX-L and Prodigy during the same visit. Bland-Altman analysis, linear regressions, and paired t-test were performed to evaluate the consistency of measurements and to establish a cross-calibration equation. The average Prodigy values for TB and lumbar spine bone mineral density (BMD) and content (BMC) were 2.7%, 2.4% and 1.6%, 1.6% higher than those of DPX-L, respectively (pProdigy-assessed bone area (BA) was lower by 1.4% for TBBA (pProdigy was higher by 6.9% (pProdigy devices were highly correlated, showing R(2) values ranging from 0.976 for FM to 0.994 for SBMC. The results of this study document a necessity for implementation of calculated cross-calibration equations to transform DPX-L-based local pediatric references into a novel Prodigy system. Copyright (c) 2010 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  1. Interferometric X-Ray Imaging of Breast Cancer Specimens at 51 keV X-Ray Energy

    Science.gov (United States)

    Takeda, Tohoru; Wu, Jin; Tsuchiya, Yoshinori; Yoneyama, Akio; Lwin, Thet Thet; Aiyoshi, Yuji; Zeniya, Tsutomu; Hyodo, Kazuyuki; Ueno, Ei

    2004-08-01

    The feasibility of the interferometric X-ray imaging technique is examined for revealing the features of breast cancer specimens. The interferometric X-ray imaging system consisted of an asymmetrically cut silicon crystal, a monolithic X-ray interferometer, a phase-shifter, an object cell, and an X-ray CCD camera. Ten 10-mm-thick formalin-fixed breast cancer specimens were imaged at 51 keV, and these images were compared with absorption-contrast X-ray images obtained at 18 keV monochromatic synchrotron X-ray. The interferometric X-ray images clearly depicted the essential features of the breast cancer such as microcalcification down to a size of 0.036 mm, spiculation, and detailed inner soft tissue structures closely matched with histopathological morphology, while the absorption-contrast X-ray images obtained using nearly the same X-ray dose only resolved microcalcification down to a size of 0.108 mm and spiculation. The interferometric X-ray imaging technique can be considered to be an innovative technique for the early and accurate diagnosis of breast cancer using an extremely low X-ray dose.

  2. Soft x-ray lasers

    International Nuclear Information System (INIS)

    Matthews, D.L.; Rosen, M.D.

    1988-01-01

    One of the elusive dreams of laser physicists has been the development of an x-ray laser. After 25 years of waiting, the x-ray laser has at last entered the scientific scene, although those now in operation are still laboratory prototypes. They produce soft x rays down to about five nanometers. X-ray lasers retain the usual characteristics of their optical counterparts: a very tight beam, spatial and temporal coherence, and extreme brightness. Present x-ray lasers are nearly 100 times brighter that the next most powerful x-ray source in the world: the electron synchrotron. Although Lawrence Livermore National Laboratory (LLNL) is widely known for its hard-x-ray laser program which has potential applications in the Strategic Defense Initiative, the soft x-ray lasers have no direct military applications. These lasers, and the scientific tools that result from their development, may one day have a place in the design and diagnosis of both laser fusion and hard x-ray lasers. The soft x-ray lasers now in operation at the LLNL have shown great promise but are still in the primitive state. Once x-ray lasers become reliable, efficient, and economical, they will have several important applications. Chief among them might be the creation of holograms of microscopic biological structures too small to be investigated with visible light. 5 figs

  3. X-ray tube

    International Nuclear Information System (INIS)

    Mayo, B.J.

    1980-01-01

    An x-ray tube in which the x-ray origin is scanned on a circle around the patient, comprises a ring-shaped anode, an electron beam travelling along a circular path being deflected onto the anode at the desired positions. The electron beam path may be in a plane parallel to the anode and perhaps at the same radius. It may be in the same plane as a transmission target/anode and at a greater radius. The anode should extend over at least 180 0 although it may extend to 360 0 . Electrostatic means may be provided to constrain the beam to the circular path and further electrostatic means deflect it to the anode of the beam and ensure it is focused at the point of incidence. Collimators provide a planar fan-shaped beam and the anode may be shaped to attenuate side lobes of the radiation. Electrode collects electrons not deflected. The focal regions may be adjacent or otherwise. Coils may provide periodic focusing to overcome space charge dispersion and dynamic adjustment of the focusing before deflection ensures focusing at target incidence. Focusing may be absent near the deflection region, and current in the coil section near the focal region should be zero. (author)

  4. Medical Imaging Teacher: A program to simulate X-ray images of the body by considering kVp, mAs and FFD values

    Directory of Open Access Journals (Sweden)

    Umit Kara

    2017-06-01

    Full Text Available Introduction: Teaching styles and methods have been constantly changing in the recent years. In the 1980s and 90s, the world was introduced to various developed devices, such as smart boards and early generation smart phones that had an immediate innovative effect on education. These advancements has resulted in a considerable improvement in the current educational techniques. The innovations in medical techniques and their quality is of paramount importance. The aim of this study was to provide an innovative and useful software on radiological applications and contribute to the related literature. Materials and Methods: The Medical Imaging Teacher (MIT program was created and the prototype application was implemented on the Android platform for free use. The programing and testing of the usability of the application were performed by the users of the Google Play Store. Results: In this program, we have developed new software to simulate the X-ray images of the body by considering the peak kilovoltage (kVp, milliamperage per second (mAs, and film focus distance (FFD values. The application has been downloaded more than 1,000 times without paid advertising. We enrolled 131 participants, who made comments and gave 4.8 points on average. Conclusion: It can be concluded that with innovative digital programs, such as the MIT, the medical machine-based learning and medical applications have risen to new levels. The software on medical testing and examination is gaining increasing popularity among the health-related applications for smart phones.

  5. Preparation of specimens for analysis by: X-ray diffraction and X-ray fluorescence analysis

    International Nuclear Information System (INIS)

    Banos L, L.

    2004-01-01

    Specimen preparation is one of the most important requirements in the analysis of samples by X-ray Diffraction and X-ray Fluorescence. This statement is especially true for samples containing different types of materials. There are many forms of specimen suitable for X-ray analysis and the type of the sample as received will generally determine the method of pretreatment. It is convenient to refer to the material received for analysis as the sample, and that, which is actually analyzed as the specimen. The powder Diffraction method assumes that the particles in the specimen are ideally random orientation and that there are enough crystallites in the specimen to achieve a representative intensity distribution for these crystallites. X ray Fluorescence is essentially a comparative method of analysis, it is vital that all standards and unknowns be presented to the spectrometer in a reproducible and identical manner. (Author) 3 refs., 6 figs

  6. X-ray table

    International Nuclear Information System (INIS)

    Craig, J.R.; Otto, G.W.

    1980-01-01

    An X-ray radiographic or fluoroscopic table is described which includes a film holder with a frame attached to a cable running over end pulleys for positioning the holder longitudinally as desired under the table top. The holder has a front opening to receive a cassette-supporting tray which can be slid out on tracks to change the cassette. A reed switch on the frame is opened by a permanent magnet on the tray only when the tray is half-way out. When the switch is closed, an electromagnet locks the pulley and the holder in place. The holder is thus automatically locked in place not only during exposure (tray in) but when the tray is out for changing the cassette. To re-position the holder, the operator pulls the tray half-out and, using the tray itself, pushes the holder along the table, the holder being counterbalanced by a weight. (author)

  7. X-ray equipment

    International Nuclear Information System (INIS)

    Redmayne, I.G.B.

    1988-01-01

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

  8. X-ray equipment

    Energy Technology Data Exchange (ETDEWEB)

    Redmayne, I.G.B.

    1988-01-06

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

  9. Chest X-ray of the neonate

    International Nuclear Information System (INIS)

    Puig, S.; Hoermann, M.; Rand, T.; Schaefer-Prokop, C.; Ponhold, W.; Kuhle, S.; Rebhandl, W.

    2000-01-01

    In diagnostic imaging of thoracic pathologies in mature and especially immature neonates, chest X-ray has a leading position. Profound knowledge of the normal chest X-ray and the potential physiological perinatal changes is the basic requirement for interpretation of the X-ray of a neonate. Childhood pathologie: Many congenital and acquired diseases that the radiologist is faced with in neonatology are unknown in the imaging of adults. Many of these changes are life-threatening or may have an impact on the patient's future quality of life. Therefore, early diagnosis in close cooperation with the paediatrician is essential. We give here an overview of the most important pathologic changes that the radiologist may be confronted with in daily routine. (orig.) [de

  10. Unwrapping an Ancient Egyptian Mummy Using X-Rays

    Science.gov (United States)

    Hughes, Stephen W.

    2010-01-01

    This article describes a project of unwrapping an ancient Egyptian mummy using x-ray computed tomography (CT). About 600 x-ray CT images were obtained through the mummified body of a female named Tjetmutjengebtiu (or Jeni for short), who was a singer in the great temple of Karnak in Egypt during the 22nd dynasty (c 945-715 BC). The x-ray CT images…

  11. X-ray instrumentation in astronomy

    International Nuclear Information System (INIS)

    Cuhlane, J.L.

    1985-01-01

    This book presents the proceedings of a conference devoted to x-ray instrumentation in astronomy. Special sections are: AXAF X-Ray Optical Systems; Specialized X-Ray Systems; X-Ray Optical Systems I; X-Ray Optical Systems II; Gas Filled X-Ray Detectors II; The NASA Advanced X-Ray Astrophysics Facility; X-Ray and EUV Spectrometers; Microchannel Plates; and Solid State Detectors

  12. X-Ray Lasers 2016

    CERN Document Server

    Bulanov, Sergei; Daido, Hiroyuki; Kato, Yoshiaki

    2018-01-01

    These proceedings comprise a selection of invited and contributed papers presented at the 15th International Conference on X-Ray Lasers (ICXRL 2016), held at the Nara Kasugano International Forum, Japan, from May 22 to 27, 2016. This conference was part of an ongoing series dedicated to recent developments in the science and technology of x-ray lasers and other coherent x-ray sources with additional focus on supporting technologies, instrumentation and applications.   The book showcases recent advances in the generation of intense, coherent x-rays, the development of practical devices and their applications across a wide variety of fields. It also discusses emerging topics such as plasma-based x-ray lasers, 4th generation accelerator-based sources and higher harmonic generations, as well as other x-ray generation schemes.

  13. Topological X-Rays Revisited

    Science.gov (United States)

    Lynch, Mark

    2012-01-01

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

  14. X-raying with low dose irradiation

    International Nuclear Information System (INIS)

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

    2001-01-01

    with higher frequency of a pulsation the share of unproductive radiation is higher. At x-raying controlled by the grid pulses are generated by the x-ray tube with the grid control. The grid, located between the cathode and the anode, passes the electron cloud without the expenses of time for dispersal and attenuation. It gives sharply outlined, rectangular x-ray pulses with homogeneous quality of radiation. Function GC F -x-raying controlled by the grid - enables to receive precisely outlined contours of moving objects: a heart, a gullet, - and also to carry out examination of the children without information loss during simultaneous dose decrease. Besides the image remains precise even during the movement of the electron-optical converter. Owing to radiation parameters adjustment during the examination the effect of the lighted image is eliminated. X-raying devices Easy Diagnose and Diagnose-76 'Philips' are equipped with the system of digital x-ray image processing besides they are completed with the x-ray tube with Grid Controlled Fluoroscopy that allows to carry out pulse x-raying with number of pulses 2, 3, 6 and 12 per a second. So, with 12 pulses per second the irradiation dose in comparison with continuous radiation decreases on 40%. The examinations of a chest, gullet, stomach and thick gut were carried out at the frequency of 12 and 6 pulses per second. In the hospital of the Ministry of Internal Affairs where device Easy Diagnose is established, at examinations of a gastro enteric path (stomach x-raying, irrigoscopy) usually pulse x-raying is used with frequency 12 pulses per second. It allows significantly reduce the beam load on a patient. The calculation of beam loads on a patient was carried out on the basis of exposition dose level at the beam input in the body of a patient (entrance dose). The way is applied for especially exact calculations, as definitions of effective doses on separate organs and all body are difficult. The irradiation dose is in

  15. X-ray filtration apparatus

    International Nuclear Information System (INIS)

    Thompson, G.

    1992-01-01

    This invention relates to an X-ray shielding support device. In spite of considerable development in X-ray taking techniques, a need still exists for effective shielding, inter alia, to compensate for variations in the thickness, density and the absorption properties of the object being studied. By appropriate shielding, the X-ray image produced is of sufficient detail, contrast and intensity over its entire area to constitute a useful diagnostic aid. It is also desirable to subject the patient to the smallest possible X-ray dosage. 4 figs

  16. X-ray Absorption Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yano, Junko; Yachandra, Vittal K.

    2009-07-09

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

  17. Anomalies in dual energy X-ray absorptiometry measurements of total-body bone mineral during weight change using Lunar, Hologic and Norland instruments.

    Science.gov (United States)

    Tothill, P; Laskey, M A; Orphanidou, C I; van Wijk, M

    1999-07-01

    A previous study showed that measurements of total-body bone mineral changes made with a Hologic QDR 1000W were unreliable when the subjects underwent weight change. The study has been extended to dual energy X-ray absorptiometry (DXA) apparatus from other manufacturers. Re-analysis of published results during weight loss using a Lunar DPX showed that they varied with the software used. Using the Extended mode, there was a 1% loss of bone mineral areal density (BMD), but no significant change in bone mineral content (BMC) or bone area (BA) following a weight loss of 16 kg, whereas the use of the Standard mode led to a larger fall of BMC and BMD. Similar findings arose from the consideration of two studies using Norland XR 26 HS absorptiometers. On the other hand, separation of two groups with similar weight changes from the population studied with a Hologic QDR 1000W confirmed that BMC changed directly with weight, but there was an inverse relationship for BMD, owing to an inappropriate change of BA. The use of Hologic Enhanced and Standard software modes led to significant differences in initial readings and measured changes. With each instrument there was a strong correlation between changes in BA and changes in BMC. When 6 kg of lard was wrapped around the limbs of volunteers or a semi-anthropomorphic phantom to simulate weight change, there were spurious increases of measured BMC and BA by about 5% with each instrument. There were no changes of BMD with Lunar, variable results with Norland, but decreases with Hologic. The results observed in vivo could be explained by the effects of fat changes, without there being any real change of bone mineral. Changes of BMD in the skeleton of the phantom were underestimated with all three brands. The anomaly observed with the Hologic QDR 1000W is less apparent with a Lunar DPX or a Norland XR 26, but there are sufficient uncertainties for all total-body measurements during weight change to be treated with suspicion.

  18. Whole-body CT with high heat-capacity X-ray tube and automated tube current modulation--effect of tube current limitation on contrast enhancement, image quality and radiation dose.

    Science.gov (United States)

    Kanematsu, Masayuki; Kondo, Hiroshi; Miyoshi, Toshiharu; Goshima, Satoshi; Noda, Yoshifumi; Tanahashi, Yukichi; Bae, Kyongtae T

    2015-05-01

    To evaluate the effect of tube current limitation on contrast enhancement, image quality, and radiation dose in whole-body 64-detector CT with a high heat-capacity X-ray tube and automated tube current modulation. One hundred eighteen patients were randomized into three whole-body CT protocols: tube current limitation at 210 mA, 450 mA, and no limitation. Signal-to-noise ratio (SNR), dose-length product (DLP), estimated effective dose (ED), and image quality were assessed. Mean SNR of aorta was comparable among protocols, but that of liver was somewhat lower in 210-mA than in 450-mA and no-limitation protocols (pX-ray tube, an appropriate tube current limitation setting may help reduce excessive radiation dose without significant compromise in diagnostic acceptability. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. Temporal characteristic analysis of laser-modulated pulsed X-ray source for space X-ray communication

    Science.gov (United States)

    Hang, Shuang; Liu, Yunpeng; Li, Huan; Tang, Xiaobin; Chen, Da

    2018-04-01

    X-ray communication (XCOM) is a new communication type and is expected to realize high-speed data transmission in some special communication scenarios, such as deep space communication and blackout communication. This study proposes a high-speed modulated X-ray source scheme based on the laser-to-X-ray conversion. The temporal characteristics of the essential components of the proposed laser-modulated pulsed X-ray source (LMPXS) were analyzed to evaluate its pulse emission performance. Results show that the LMPXS can provide a maximum modulation rate up to 100 Mbps which is expected to significantly improve the data rate of XCOM.

  20. X-ray upper airway changes in individuals suffering from obstructive respiratory disorders during sleep

    International Nuclear Information System (INIS)

    Shakhov, A.A.; Rabukhina, N.A.; Nerobeev, A.I.; Vasil'ev, A.Yu.

    2000-01-01

    Obstructive respiratory disorders during sleep present an important medical and social problem. Serious dysfunctions of cardiovascular, nervous, endocrine and other vital systems of the body reduce longevity and life quality. On the other hand, load nocturnal snore and abnormal during sleepiness cause great damage to family life, reduce working capacity and induce accidents. X-ray visualization of the upper airways is essential in diagnosing obstructive upper airway states and selecting patients for surgical treatment. The paper presents the author's own experience in using various X-ray diagnostic methods in patients with chronic snore and obstructive sleep apnoea-hypopnoea syndrome [ru

  1. Body composition during weight loss in obese patients estimated by dual energy X-ray absorptiometry and by total body potassium

    DEFF Research Database (Denmark)

    Hendel, H W; Gotfredsen, A; Andersen, T

    1996-01-01

    OBJECTIVE: To validate the ability of DXA to measure total body composition before and after weight loss and the composition of the lost body mass. DESIGN: Cross sectional and follow-up study of body composition before and after a weight loss of 10.6 +/- 6.8 kg. SUBJECTS: 31 obese subjects...... that estimated by TBK (7.6% FFM and 92.4% FM by TBK; 11% FFM and 89% FM by DXA). CONCLUSION: DXA estimates accurately the body composition and the composition of weight loss in groups of obese subjects. However, the scan table may be too small for patients weighing more than 95 kg....

  2. Efficient lensing element for x-rays

    International Nuclear Information System (INIS)

    Ceglio, N.M.; Smith, H.I.

    1977-01-01

    An efficient x-ray lens with an effective speed of order less than approximately f/50 for lambda greater than approximately 10 A x-rays is described. Fabrication of this lensing element appears feasible using existing microfabrication technology. Diffraction and refraction are coupled in a single element to achieve efficient x-ray concentration into a single order focal spot. Diffraction is used to produce efficient ray bending (without absorption) while refraction is used only to provide appropriate phase adjustment among the various diffraction orders to insure what is essentially a single order output. The mechanism for ray bending (diffraction) is decoupled from the absorption mechanism. Refraction is used only to achieve small shifts in phase so that the associated attenuation need not be prohibitive. The x-ray lens might be described as a Blazed Fresnel Phase Plate (BFPP) with a spatially distributed phase shift within each Fresnel zone. The spatial distribution of the phase shifts is chosen to concentrate essentially all of the unabsorbed energy into a single focal spot. The BFPP transforms the incident plane wave into a converging spherical wave having an amplitude modulation which is periodic in r 2 . As a result of the periodic amplitude modulation, the BFPP will diffract energy into foci other than the first order real focus. In cases of small absorption such effects are negligible and practically all the unabsorbed energy is directed into the first order real focus

  3. [Comparison whole-body muscle mass assessed by dual-energy X-ray absorptiometry and multi-frequency bioelectrical impedance in overweight and obese adults].

    Science.gov (United States)

    Wang, Z H; Dong, Y H; Yang, Y D; Wang, S; Ma, J

    2017-03-06

    Objective: To investigate consistency of whole-body muscle mass (WBMM) assessed using multi-frequency bioelectrical impedance analysis (MF-BIA) and dual energy X-ray Absorptiometry (DXA) measurement, and to delvelop the correction regression formulas for the method of MF-BIA. Methods: 1 488 participants who resided in Beijing longer than one year, under 22 to 55 years of age, with self-report BMI ≥24 kg/m(2) were voluntarily recruited based on convenience sampling in Beijing, from April 1(st) 2014 to May 2(nd) 2014. After excluded 171 participants who BMI ≤24 kg/m(2) or with organic diseases when physical examination, Finally 1 317 overweight/obese participants were enrolled into the current study. All the subjects received the measurement of WBMM using both MF-BIA and DXA methods. The paired-samples T test was used to compare the difference of measurement values between MF-BIA and DXA methods. We evaluated the agreement of WBMM measured by MF-BIA and DXA using the interclass correlation coefficients (ICC) and the Bland-Altman plots, and using linear regression method established correction regression formulas. Results: The differences of overweight male, obese male, overweight female, and obese female were (3.29 ± 1.94), (2.05 ± 2.65), (0.17 ± 1.85), and (-2.22 ± 2.89) kg between methods of MF-BIA and DXA, respectively; Except the overweight female, the others groups had the statistically significant difference ( Pobese male, overweight female, and obese female were 0.958, 0.956, 0.911, and 0.851, respectively ( Pobese male population: y (DXA)=-3.646 + 1.026 x (MF-BIA); overweight female groups: y (DXA)=-4.800 + 1.117 x (MF-BIA); obese female group: y (DXA)=-9.884+ 1.287 x (MF-BIA). Conclusion: The correlation and agreement of WBMM measured by the methods of BIA and DXA were relative weak in Chinese excess weight male and obese female adults. Therefore, measuring WBMM by MF-BIA method in these adults should be corrected to reduce bias compared with the DXA

  4. Evaluering af overensstemmelsen af body condition score og feline body mass index sammenlignet med dual energy X-ray absorptiometry hos katte

    DEFF Research Database (Denmark)

    Falkenberg, Michael; Hølmkjær, Kirsten Madsen; Cronin, Anna

    2016-01-01

    Formål: Obesitet er et stigende problem blandt katte, og der er derfor brug for nemme, billige og hurtige metoder til vurdering af kattes kropssammensætning i praksis. Indeværende studie sammenligner to klinisk applicerbare metoder: Body condition score (BCS) og feline body mass index (FBMI) mod...

  5. Whole-body bone mineral content, lean body mass, and fat mass measured by dual-energy x-ray absorptiometry in a population of normal Canadian children and adolescents

    Energy Technology Data Exchange (ETDEWEB)

    Sala, A. [McMaster Children' s Hospital, Hamilton, Ontario (Canada); McMaster Univ., Dept. of Pediatrics, Hamilton, Ontario (Canada); Univ. of Milan-Bicocca, Monza (Italy); Webber, C.E. [Hamilton Health Sciences, Dept. of Nuclear Medicine, Hamilton, Ontario (Canada); McMaster Univ., Dept. of Radiology, Hamilton, Ontario (Canada)]. E-mail: webber@hhsc.ca; Morrison, J. [McMaster Children' s Hospital, Hamilton, Ontario (Canada); Beaumont, L.F. [Hamilton Health Sciences, Dept. of Nuclear Medicine, Hamilton, Ontario (Canada); Barr, R.D. [McMaster Children' s Hospital, Hamilton, Ontario (Canada); McMaster Univ., Dept. of Pediatrics, Hamilton, Ontario (Canada)

    2007-02-15

    Measurements of body composition have evident value in evaluating growing children and adolescents, and dual-energy X-ray absorptiometry (DXA) is a tool that provides accurate measurements of whole-body bone mineral content (WBBMC), lean body mass (LBM), and fat mass (FM). To interpret such measurements in the context of ill health, normative values must be available. Such information could be expected to be regionally specific because of differences in ethnic, dietary, and physical activity determinants. In this study, DXA was performed with Hologic densitometers in normal girls (n = 91) and boys (n 88) between 3 and 18 years of age. The derivation of normal ranges is presented for boys and girls. The correlation of the sum of WBBMC, LBM, and FM with directly measured body weight was almost perfect (r > 0.997). As expected, FM and body mass index correlated strongly. The normal values for WBBMC, LBM, and FM from this study are compared with other Canadian data and with published normative data from Argentina and the Netherlands, all of which use different densitometers. The results of this study allow the calculation of z scores for each facet of body composition and facilitate the use of DXA to report routine evaluations of body composition in children and adolescents. (author)

  6. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... a large photographic negative). Today, most images are digital files that are stored electronically. These stored images are easily accessible and are frequently compared to current x-ray images for diagnosis and ... the x-ray film holder or digital recording plate under the table in the area ...

  7. Chandra's X-ray Vision

    Indian Academy of Sciences (India)

    1999-07-23

    Jul 23, 1999 ... GENERAL I ARTICLE. Chandra's X-ray Vision. K P Singh. Chandra X-ray Observatory (CXO) is a scientific satellite (moon/ chandra), named after the Indian-born Nobel laureate. Subrahmanyan Chandrasekhar - one of the foremost astro- physicists of the twentieth century and popularly known as. Chandra.

  8. Traditional x-ray imaging

    International Nuclear Information System (INIS)

    Hay, G.A.

    1982-01-01

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

  9. X-ray based extensometry

    Science.gov (United States)

    Jordan, E. H.; Pease, D. M.

    1988-01-01

    A totally new method of extensometry using an X-ray beam was proposed. The intent of the method is to provide a non-contacting technique that is immune to problems associated with density variations in gaseous environments that plague optical methods. X-rays are virtually unrefractable even by solids. The new method utilizes X-ray induced X-ray fluorescence or X-ray induced optical fluorescence of targets that have melting temperatures of over 3000 F. Many different variations of the basic approaches are possible. In the year completed, preliminary experiments were completed which strongly suggest that the method is feasible. The X-ray induced optical fluorescence method appears to be limited to temperatures below roughly 1600 F because of the overwhelming thermal optical radiation. The X-ray induced X-ray fluorescence scheme appears feasible up to very high temperatures. In this system there will be an unknown tradeoff between frequency response, cost, and accuracy. The exact tradeoff can only be estimated. It appears that for thermomechanical tests with cycle times on the order of minutes a very reasonable system may be feasible. The intended applications involve very high temperatures in both materials testing and monitoring component testing. Gas turbine engines, rocket engines, and hypersonic vehicles (NASP) all involve measurement needs that could partially be met by the proposed technology.

  10. X-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Attekum, P.M.T.M. van.

    1979-01-01

    The methods and results of X-ray photoelectron spectroscopy in the study of plasmons, alloys and gold compounds are discussed. After a comprehensive introduction, seven papers by the author, previously published elsewhere, are reprinted and these cover a wide range of the uses of X-ray photoelectron spectroscopy. (W.D.L.)

  11. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... standards used by radiology professionals. Modern x-ray systems have very ... they provide little information about muscles, tendons or joints. An MRI may ...

  12. Dental X-ray apparatus

    International Nuclear Information System (INIS)

    Weiss, M.E.

    1980-01-01

    Intra-oral dental X-ray apparatus for panoramic radiography is described in detail. It comprises a tubular target carrier supporting at its distal end a target with an inclined forward face. Image definition is improved by positioning in the path of the X-rays a window of X-ray transmitting ceramic material, e.g. 90% oxide of Be, or Al, 7% Si0 2 . The target carrier forms a probe which can be positioned in the patient's mouth. X-rays are directed forwardly and laterally of the target to an X-ray film positioned externally. The probe is provided with a detachable sleeve having V-form arms of X-ray opaque material which serve to depress the tongue out of the radiation path and also shield the roof of the mouth and other regions of the head from the X-ray pattern. A cylindrical lead shield defines the X-ray beam angle. (author)

  13. Hazard and efficiency of X-ray diagnostic investigations

    International Nuclear Information System (INIS)

    1984-01-01

    This symposium deals with the hazards and efficiency of biomedical X-ray examinations. The first articles are devoted to the effects of radiation on the human body. Special attention is paid to low dose irradiation. Later on the efficiency and necessity of X-ray examinations are discussed. Reference is made to the diagnosis of colon- and mammacarcinoma. (Auth.)

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

    Science.gov (United States)

    Zietz, Otto; Mylott, Elliot; Widenhorn, Ralf

    2015-01-01

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

  15. X-Ray Tomographic Reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Bonnie Schmittberger

    2010-08-25

    Tomographic scans have revolutionized imaging techniques used in medical and biological research by resolving individual sample slices instead of several superimposed images that are obtained from regular x-ray scans. X-Ray fluorescence computed tomography, a more specific tomography technique, bombards the sample with synchrotron x-rays and detects the fluorescent photons emitted from the sample. However, since x-rays are attenuated as they pass through the sample, tomographic scans often produce images with erroneous low densities in areas where the x-rays have already passed through most of the sample. To correct for this and correctly reconstruct the data in order to obtain the most accurate images, a program employing iterative methods based on the inverse Radon transform was written. Applying this reconstruction method to a tomographic image recovered some of the lost densities, providing a more accurate image from which element concentrations and internal structure can be determined.

  16. Investigating the level of agreement of two positioning protocols when using dual energy X-ray absorptiometry in the assessment of body composition

    Directory of Open Access Journals (Sweden)

    Flinn Shiel

    2017-10-01

    Full Text Available Background Dual energy X-ray absorptiometry (DXA is a commonly used instrument for analysing segmental body composition (BC. The information from the scan guides the clinician in the treatment of conditions such as obesity and can be used to monitor recovery of lean mass following injury. Two commonly used DXA positioning protocols have been identified—the Nana positioning protocol and the National Health and Nutrition Examination Survey (NHANES. Both protocols have been shown to be reliable. However, only one study has assessed the level of agreement between the protocols and ascertained the participants’ preference of protocol based upon comfort. Given the paucity of research in the field and the growing use of DXA in both healthy and pathological populations further research determining the most appropriate positioning protocol is warranted. Therefore, the aims of this study were to assess the level of agreement between results from the NHANES protocol and Nana protocol, and the participants’ preference of protocol based on comfort. Methods Thirty healthy participants (15 males, 15 females, aged 23–59 years volunteered to participate in this study. These participants underwent two whole body DXA scans in a single morning (Nana positioning protocol and NHANES positioning protocol, in a randomised order. Each participant attended for scanning wearing minimal clothing and having fasted overnight, refrained from exercise in the past 24 h and voided their bladders. Level of agreement, comparing NAHNES to Nana protocol was assessed using an intra-class correlation coefficient (ICC, concordance correlation coefficient (CCC and percentage change in mean. Limit of agreement comparing the two protocols were assessed using plots, mean difference and confidence limits. Participants were asked to indicate the protocol they found most comfortable. Results When assessing level of agreement between protocols both the ICC and CCC scores were very high

  17. Implications of X-ray tube parameter deviations in X-ray reference fields.

    Science.gov (United States)

    Behnke, B; Hupe, O; Ambrosi, P

    2016-02-01

    For the purpose of radiation protection, ICRU Report 57/ICRP Publication 74 provides a list of monoenergetic conversion coefficients to be used with, among others, photon reference fields generated with X-ray tubes. A comprehensive definition of these photon reference fields can be found in international standard ISO 4037; however, it lacks thorough indication of the allowed deviations of essential parameters that influence these X-ray reference fields. These parameters are the high-voltage tube potential, the thickness of the beryllium window and the purity and thickness of the filter materials used to create different radiation qualities. Small variations of these parameters can lead to significant changes in the created X-ray spectra and, hence, the spectra-dependent conversion coefficients for phantom-related radiation-protection quantities. This can lead to situations in which the conversion coefficients listed in ISO 4037 cannot be used, resulting in time-consuming spectrometry measurements. In this work, the impact on the resulting conversion coefficients is investigated using a simplified mathematical approximation model. The findings are validated with an independent X-ray spectra calculation programme. As a result, well-founded upper limit values on the allowed deviations of the essential X-ray tube parameters are proposed to be used in a future revision of ISO 4037. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. Novel CMOS Analog Signal Processing Technique for Solid-State X-Ray Sensors

    OpenAIRE

    Dlugosz, Rafal Tomasz; Iniewski, Chris

    2007-01-01

    Ability to peer into human body is an essential diagnostic tool in medicine. Out of the four major imaging modalities that include ultra-sound, magnetic resonance imaging (MRI), and positron emission tomography (PET), nuclear medicine is gaining more widespread attention. Nuclear medicine involves measurement of radiation from inside human body using in vivo pharmaceutical tracer. X-ray computed tomography (CT) and single photon emission computer tomography (SPECT) are three-dimensional (3D) ...

  19. Air displacement plethysmography, dual-energy x-ray absorptiometry, and total body water to evaluate body composition in preschool-age children

    Science.gov (United States)

    Anthropometrics and body mass index are only proxies in the evaluation of adiposity in the pediatric population. Air displacement plethysmography technology was not available for children aged 6 months to 9 years until recently. Our study was designed to test the precision of air displacement plethy...

  20. Essential trace elements content in a sudanese meal of cooked Hibiscus Sp. leaves as determined by both X-ray florescence and atomic absorption spectroscopy techniques

    International Nuclear Information System (INIS)

    Mohamed, S.M; Taha, M.H.

    2003-01-01

    Essential trace elements content of a Sudanese meal of cooked Karkadi plant leaves (Hibiscus Sp)was determined and found to be several folds higher than the average trace element content of Sudanese food as determined in twenty nine daily consumed mixed diets. Therefore, this plant can act as a promising natural supplement in cases of deficiency provided it is grown in a trace element rich soil. (Author)

  1. X-ray diffraction apparatus

    International Nuclear Information System (INIS)

    Padini, F.R.

    1978-01-01

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

  2. X-ray film calibration

    International Nuclear Information System (INIS)

    Stone, G.F.; Dittmore, C.H.; Henke, B.L.

    1986-01-01

    This paper discusses the use of silver halide x-ray films for imaging and spectroscopy which is limited by the range of intensities that can be recorded and densitometered. Using the manufacturers processing techniques can result in 10 2-3 range in intensity recorded over 0-5 density range. By modifying the chemistry and processing times, ranges of 10 5-6 can be recorded in the same density range. The authors report on x-ray film calibration work and dynamic range improvements. Changes to the processing chemistry and the resulting changes in dynamic range and x-ray sensitivity are discussed

  3. Upsurge of X-ray astronomy 230-

    International Nuclear Information System (INIS)

    Hudec, D.R.

    1978-01-01

    Instruments are described used for X-ray astronomy, namely X-ray detectors and X-ray telescopes. Unlike telescopes, the detectors do not comprise X-ray optics. A survey is given of the results obtained in solar and stellar X-ray astronomy and hypotheses are submitted on the origin of X radiation in the interstellar space. (J.B.)

  4. The evolution of X-ray clusters in a cold plus hot dark matter universe

    Science.gov (United States)

    Bryan, Greg L.; Klypin, Anatoly; Loken, Chris; Norman, Michael L.; Burns, Jack O.

    1994-01-01

    We present the first self-consistently computed results on the evolution of X-ray properties of galaxy clusters in a cold + hot dark matter (CHDM) model. We have performed a hydrodynamic plus N-body simulation for the COBE-compatible CHDM model with standard mass components: Omega(sub hot) = 0.3, Omega (sub cold) = 0.6 and Omega(sub baryon) = 0.1 (h = 0.5). In contrast with the CDM model, which fails to reproduce the observed temperature distribution function dN/dT (Bryan et al. 1994b), the CHDM model fits the observational dN/dT quite well. Our results on X-ray luminosity are less firm but even more intriguing. We find that the resulting X-ray luminosity functions at redshifts z = 0.0, 0.2, 0.4, 0.7 are well fit by observations, where they overlap. The fact that both temperatures and luminosities provide a reasonable fit to the available observational data indicates that, unless we are missing some essential physics, there is neither room nor need for a large fraction of gas in rich clusters: 10% (or less) in baryons is sufficient to explain their X-ray properties. We also see a tight correlation between X-ray luminosity and gas temperature.

  5. Micronucleus induction by repeated exposure of diagnostic X-ray on oral buccal mucosa

    International Nuclear Information System (INIS)

    Lohith Tejashvi, K.; Suchetha Kumari, N.; Shetty, Shishir Ram

    2012-01-01

    Radiography is the important diagnostic tools essential for diagnosis and planning of orthodontic treatment. X-ray is ionizing radiation which showed various effects include breaking the bond of biological molecules, inducing loss of ability of cell death, increases nuclear alterations. Micronuclei - x000D - (MN) are small chromatin bodies that appear in the cytoplasm by the - x000D - condensation of acrocentric chromosomal fragments or by whole chromosomes. This - x000D - is a sensitive indicator of genetic damage. - x000D - x000D - . To evaluate micronucleus induction by repeated exposure of diagnostic X-ray on human buccal cell. Methods: 25 patients who visiting to ABSMIDS, Department of Oral medicine and Radiology for dental checkup exposed to diagnostic X-ray more than 4 times have been selected for this study. The buccal cell for analysis was collected from the cheek mucosa by means of gentle scraping of epithelial using ice-cream sticks and placed in Buffer saline. This sample was smeared on glass slide and then fixed in methanol:glacial acetic acid (3:1). Air dried and stained with Giemsa for 15-25 minutes. Then 250 cells in each slides were analyzed under microscope and frequency of micronucleus was scored (n=4). Repeated X-ray exposed cells showed micronucleus (1.25%) and nuclear alteration (2.3%) compare to the control. Repeated X-ray exposure leads to induces detectable number of micronucleus and nuclear alterations. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-07-01

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

  7. Bone X-Ray (Radiography)

    Medline Plus

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

  8. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... evaluation with additional views or a special imaging technique. A follow-up examination may also be necessary ... radiology protection organizations continually review and update the technique standards used by radiology professionals. Modern x-ray ...

  9. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... to X-ray (Radiography) - Bone Sponsored by Please note RadiologyInfo.org is not a medical facility. Please ... is further reviewed by committees from the American College of Radiology (ACR) and the Radiological Society of ...

  10. Bone X-Ray (Radiography)

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

  11. Flash x-ray cinematography

    International Nuclear Information System (INIS)

    Stein, W.E.

    1976-01-01

    Experiments intended to provide an overview of the potential capabilities and limitations of flash x-ray cinematography as a diagnostic technique for a Fast Reactor Safety Test Facility are described. The results provide estimates of the x-ray pulse intensity required to obtain adequate radiographs of an array of fuel pins in a typical reactor configuration. An estimate of the upper limit on the pulse duration imposed by the reactor background radiation was also determined. X-ray cinematography has been demonstrated at a repetition rate limited only by the recording equipment on hand at the time of these measurements. These preliminary results indicate that flash x-ray cinematography of the motion of fuel in a Fast Reactor Test Facility is technically feasible

  12. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... fracture. guide orthopedic surgery, such as spine repair/fusion, joint replacement and fracture reductions. look for injury, ... CT Exams Arthritis X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety How to Read Your Radiology ...

  13. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... knee, leg (shin), ankle or foot. top of page What are some common uses of the procedure? A ... information about pregnancy and x-rays. top of page What does the equipment look like? The equipment typically ...

  14. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... will analyze the images and send a signed report to your primary care or referring physician , who ... Medicine Radiation Safety How to Read Your Radiology Report Images related to X-ray (Radiography) - Bone Sponsored ...

  15. X-Ray Assembler Data

    Data.gov (United States)

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

  16. Dental X-ray apparatus

    International Nuclear Information System (INIS)

    Weiss, M.E.

    1980-01-01

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

  17. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... bear denotes child-specific content. Related Articles and Media Radiation Dose in X-Ray and CT Exams ... or your insurance provider to get a better understanding of the possible charges you will incur. Web ...

  18. Bone X-Ray (Radiography)

    Medline Plus

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

  19. X-Rays - Multiple Languages

    Science.gov (United States)

    ... Expand Section Barium Swallow - 简体中文 (Chinese, Simplified (Mandarin dialect)) Bilingual PDF Health Information Translations Chest X-Ray - 简体中文 (Chinese, Simplified (Mandarin dialect)) ...

  20. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Leave jewelry at home and wear loose, comfortable clothing. You may be asked to wear a gown. ... appliances, eye glasses and any metal objects or clothing that might interfere with the x-ray images. ...

  1. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... abnormalities. This exam requires little to no special preparation. Tell your doctor and the technologist if there ... prepare? Most bone x-rays require no special preparation. You will be asked to remove some of ...

  2. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... in metabolic conditions. assist in the detection and diagnosis of bone cancer . locate foreign objects in soft ... frequently compared to current x-ray images for diagnosis and disease management. top of page How is ...

  3. Bone X-Ray (Radiography)

    Medline Plus

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

  4. Bone X-Ray (Radiography)

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    Full Text Available ... of page What will I experience during and after the procedure? A bone x-ray examination itself ... available in emergency rooms, physician offices, ambulatory care centers, nursing homes and other locations, making it convenient ...

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... white on the x-ray, soft tissue shows up in shades of gray and air appears black. ... who will discuss the results with you. Follow-up examinations may be necessary. Your doctor will explain ...

  6. Bone X-Ray (Radiography)

    Medline Plus

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

  7. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... patient. top of page How does the procedure work? X-rays are a form of radiation like ... taken of the unaffected limb, or of a child's growth plate (where new bone is forming), for ...

  8. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... procedure. You may experience discomfort from the cool temperature in the examination room. You may also find ... have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures ...

  9. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... The teddy bear denotes child-specific content. Related Articles and Media Radiation Dose in X-Ray and ... facilities database . This website does not provide cost information. The costs for specific medical imaging tests, treatments ...

  10. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... limb, or of a child's growth plate (where new bone is forming), for comparison purposes. When the ... Exams Arthritis X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety How to Read Your Radiology Report ...

  11. Bone X-Ray (Radiography)

    Medline Plus

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

  12. X-ray screening materials

    International Nuclear Information System (INIS)

    Wardley, R.B.

    1981-01-01

    This invention relates to x-ray screening materials and especially to materials in sheet form for use in the production of, for example, protective clothing such as aprons and lower back shields, curtains, mobile screens and suspended shields. The invention is based on the observation that x-ray screening materials in sheet form having greater flexiblity than the hitherto known x-ray screening materials of the same x-ray absorber content can be produced if, instead of using a single sheet of filled sheet material of increased thickness, one uses a plurality of sheets of lesser thickness together forming a laminar material of the desired thickness and one bonds the individual sheets together at their edges and, optionally, at other spaced apart points away from the edges thereby allowing one sheet to move relative to another. (U.K.)

  13. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... ensures x-ray image quality. top of page Who interprets the results and how do I get ... report to your primary care or referring physician , who will discuss the results with you. Follow-up ...

  14. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... no special preparation. Tell your doctor and the technologist if there is any possibility you are pregnant. ... should always inform their physician and x-ray technologist if there is any possibility that they are ...

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... is commonly used to diagnose fractured bones or joint dislocation. Bone x-rays are the fastest and ... to view and assess bone fractures, injuries and joint abnormalities. This exam requires little to no special ...

  16. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the lowest radiation dose possible while producing the best images for evaluation. National and international radiology protection organizations continually review and update the technique standards used by radiology professionals. Modern x-ray ...

  17. Miniature x-ray source

    Science.gov (United States)

    Trebes, James E.; Bell, Perry M.; Robinson, Ronald B.

    2000-01-01

    A miniature x-ray source utilizing a hot filament cathode. The source has a millimeter scale size and is capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature source consists of a compact vacuum tube assembly containing the hot filament cathode, an anode, a high voltage feedthru for delivering high voltage to the cathode, a getter for maintaining high vacuum, a connector for initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is fabricated from highly x-ray transparent materials, such as sapphire, diamond, or boron nitride.

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... examination may also be necessary so that any change in a known abnormality can be monitored over ...

  19. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... for more information about pregnancy and x-rays. A Word About Minimizing Radiation Exposure Special care is ... taking our brief survey: Survey Do you have a personal story about radiology? Share your patient story ...

  20. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... while the x-ray picture is taken to reduce the possibility of a blurred image. The technologist ... accredited facilities database . This website does not provide cost information. The costs for specific medical imaging tests, ...

  1. Duodenal X-ray diagnostics

    International Nuclear Information System (INIS)

    Scheppach, W.

    1982-01-01

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

  2. Bone X-Ray (Radiography)

    Medline Plus

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

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the oldest and most frequently used form of medical imaging. A bone x-ray makes images of any ... a radiologist or other physician. To locate a medical imaging or radiation oncology provider in your community, you ...

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... radiation dose for this procedure varies. See the Safety page for more information about radiation dose. Women ...

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... patient. top of page How does the procedure work? X-rays are a form of radiation like ... instead of ionizing radiation to create diagnostic images, has also been useful for injuries around joints, and ...

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

    International Nuclear Information System (INIS)

    Yamamoto, Keiichi; Miyazaki, Shigeru

    2003-01-01

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

  7. Accelerator x-ray sources

    CERN Document Server

    Talman, Richard

    2007-01-01

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

  8. X-ray data processing

    OpenAIRE

    Powell, Harold R.

    2017-01-01

    The method of molecular structure determination by X-ray crystallography is a little over a century old. The history is described briefly, along with developments in X-ray sources and detectors. The fundamental processes involved in measuring diffraction patterns on area detectors, i.e. autoindexing, refining crystal and detector parameters, integrating the reflections themselves and putting the resultant measurements on to a common scale are discussed, with particular reference to the most c...

  9. X-ray computed tomography

    International Nuclear Information System (INIS)

    Kalender, Willi A

    2006-01-01

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

  10. Which is the best cutoff of body mass index to identify obesity in female patients with rheumatoid arthritis? A study using dual energy X-ray absorptiometry body composition.

    Science.gov (United States)

    Guimarães, Maria Fernanda B Resende; Pinto, Maria Raquel da Costa; Raid, Renata G Santos Couto; Andrade, Marcus Vinícius Melo de; Kakehasi, Adriana Maria

    Standard anthropometric measures used to diagnose obesity in the general population may not have the same performance in patients with rheumatoid arthritis. To determine cutoff points for body mass index (BMI) and waist circumference (WC) for detecting obesity in women with rheumatoid arthritis (RA) by comparing these standard anthropometric measures to a dual-energy X-ray absorptiometry (DXA)-based obesity criterion. Adult female patients with more than six months of diagnosis of RA underwent clinical evaluation, with anthropometric measures and body composition with DXA. Eighty two patients were included, mean age 55±10.7 years. The diagnosis of obesity in the sample was about 31.7% by BMI, 86.6% by WC and 59.8% by DXA. Considering DXA as golden standard, cutoff points were identified for anthropometric measures to better approximate DXA estimates of percent body fat: for BMI value≥25kg/m 2 was the best for definition of obesity in female patients with RA, with sensitivity of 80% and specificity of 60%. For WC, with 80% of sensitivity and 35% of specificity, the best value to detect obesity was 86cm. A large percentage of patients were obese. The traditional cutoff points used for obesity were not suitable for our sample. For this female population with established RA, BMI cutoff point of 25kg/m 2 and WC cutoff point of 86cm were the most appropriate to detect obesity. Copyright © 2016 Elsevier Editora Ltda. All rights reserved.

  11. Expression, purification, crystallization and preliminary X-ray diffraction analysis of an essential lipoprotein implicated in cell-wall biosynthesis in Mycobacteria

    Energy Technology Data Exchange (ETDEWEB)

    Marland, Zara; Beddoe, Travis; Zaker-Tabrizi, Leyla [The Protein Crystallography Unit, Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800 (Australia); ARC Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Clayton, Victoria 3800 (Australia); Coppel, Ross L.; Crellin, Paul K., E-mail: paul.crellin@med.monash.edu.au [ARC Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Clayton, Victoria 3800 (Australia); Department of Microbiology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800 (Australia); Rossjohn, Jamie, E-mail: paul.crellin@med.monash.edu.au [The Protein Crystallography Unit, Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800 (Australia); ARC Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Clayton, Victoria 3800 (Australia)

    2005-12-01

    A lipoprotein implicated in mycobacterial cell-wall biosynthesis, LpqW, was expressed in E. coli. Crystals were obtained that diffracted to 2.4 Å resolution. Mycobacterium tuberculosis is a renewed cause of devastation in the developing world. Critical to the success of this re-emerging pathogen is its unusual waxy cell wall, which is rich in rare components including lipoarabinomannan (LAM) and its precursors, the phosphatidylinositol mannosides (PIMs). Balanced synthesis of these related glycolipids is intrinsic to both cell-wall integrity and virulence in M. tuberculosis and presents a promising, albeit poorly defined, therapeutic target. Here, the expression, purification and crystallization of an essential 600-amino-acid lipoprotein, LpqW, implicated in this process are reported. Crystals of LpqW were grown using 20–24%(w/v) PEG 4000, 8–16%(v/v) 2-propanol, 100 mM sodium citrate pH 5.5 and 10 mM DTT. A complete data set was collected at 2.4 Å using synchrotron radiation on a crystal belonging to space group C222, with unit-cell parameters a = 188.57, b = 312.04, c = 104.15 Å. Structure determination is under way.

  12. Expression, purification, crystallization and preliminary X-ray diffraction analysis of an essential lipoprotein implicated in cell-wall biosynthesis in Mycobacteria

    International Nuclear Information System (INIS)

    Marland, Zara; Beddoe, Travis; Zaker-Tabrizi, Leyla; Coppel, Ross L.; Crellin, Paul K.; Rossjohn, Jamie

    2005-01-01

    A lipoprotein implicated in mycobacterial cell-wall biosynthesis, LpqW, was expressed in E. coli. Crystals were obtained that diffracted to 2.4 Å resolution. Mycobacterium tuberculosis is a renewed cause of devastation in the developing world. Critical to the success of this re-emerging pathogen is its unusual waxy cell wall, which is rich in rare components including lipoarabinomannan (LAM) and its precursors, the phosphatidylinositol mannosides (PIMs). Balanced synthesis of these related glycolipids is intrinsic to both cell-wall integrity and virulence in M. tuberculosis and presents a promising, albeit poorly defined, therapeutic target. Here, the expression, purification and crystallization of an essential 600-amino-acid lipoprotein, LpqW, implicated in this process are reported. Crystals of LpqW were grown using 20–24%(w/v) PEG 4000, 8–16%(v/v) 2-propanol, 100 mM sodium citrate pH 5.5 and 10 mM DTT. A complete data set was collected at 2.4 Å using synchrotron radiation on a crystal belonging to space group C222, with unit-cell parameters a = 188.57, b = 312.04, c = 104.15 Å. Structure determination is under way

  13. Center for X-Ray Optics, 1992

    International Nuclear Information System (INIS)

    1993-08-01

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

  14. Characteristics of x-ray beams in two commercial multidetector computed tomography simulators: Monte Carlo simulations.

    Science.gov (United States)

    Kim, Sangroh; Song, Haijun; Movsas, Benjamin; Chetty, Indrin J

    2012-01-01

    As multidetector computed tomography (MDCT) scanning is routinely performed for treatment planning in radiation oncology, understanding the characteristics of the MDCT x-ray beam is essential to accurately estimate patient dose. The purpose of this study is to characterize the x-ray beams of two commercial MDCT simulators widely used in radiation oncology by Monte Carlo (MC) simulations. X-ray tube systems of two wide bore MDCT scanners (GE LightSpeed RT 4 and Philips Brilliance Big Bore) were modeled in the BEAMNRC/EGSNRC MC system. All the tube components were modeled from targets to bowtie filters. To validate our MC models, the authors measured half-value layers (HVL) using aluminum sheets and multifunctional radiation detectors and compared them to those obtained from MC simulations for 120 kVp beams. The authors also compared x-ray spectra obtained from MC simulation to the data provided by manufacturers. Additionally, lateral/axial beam profiles were measured in-air using radiochromic films and compared to the MC results. To understand the scatter effect, the authors also derived the scatter-to-primary energy fluence ratio (SPR) profiles and calculated the total SPR for each CT system with the CT dose index (CTDI) head and body phantoms using the BEAMNRC system. The authors found that the HVL, x-ray spectrum and beam profiles of the MC simulations agreed well with the manufacturer-specified data within 1%-10% on average for both scanners. The total SPR were ranged from 7.8 to 13.7% for the head phantom and from 10.7 to 18.9% for the body phantom. The authors demonstrate the full MC simulations of two commercial MDCT simulators to characterize their x-ray beams. This study may be useful to establish a patient-specific dosimetry for the MDCT systems.

  15. The Mapping X-ray Fluorescence Spectrometer (MapX)

    Science.gov (United States)

    Sarrazin, P.; Blake, D. F.; Marchis, F.; Bristow, T.; Thompson, K.

    2017-12-01

    Many planetary surface processes leave traces of their actions as features in the size range 10s to 100s of microns. The Mapping X-ray Fluorescence Spectrometer (MapX) will provide elemental imaging at 100 micron spatial resolution, yielding elemental chemistry at a scale where many relict physical, chemical, or biological features can be imaged and interpreted in ancient rocks on planetary bodies and planetesimals. MapX is an arm-based instrument positioned on a rock or regolith with touch sensors. During an analysis, an X-ray source (tube or radioisotope) bombards the sample with X-rays or alpha-particles / gamma-rays, resulting in sample X-ray Fluorescence (XRF). X-rays emitted in the direction of an X-ray sensitive CCD imager pass through a 1:1 focusing lens (X-ray micro-pore Optic (MPO)) that projects a spatially resolved image of the X-rays onto the CCD. The CCD is operated in single photon counting mode so that the energies and positions of individual X-ray photons are recorded. In a single analysis, several thousand frames are both stored and processed in real-time. Higher level data products include single-element maps with a lateral spatial resolution of 100 microns and quantitative XRF spectra from ground- or instrument- selected Regions of Interest (ROI). XRF spectra from ROI are compared with known rock and mineral compositions to extrapolate the data to rock types and putative mineralogies. When applied to airless bodies and implemented with an appropriate radioisotope source for alpha-particle excitation, MapX will be able to analyze biogenic elements C, N, O, P, S, in addition to the cations of the rock-forming elements >Na, accessible with either X-ray or gamma-ray excitation. The MapX concept has been demonstrated with a series of lab-based prototypes and is currently under refinement and TRL maturation.

  16. X-ray absorption spectroscopy: EXAFS [Extended X-ray Absorption Fine Structure] and XANES [X-ray Absorption Near Edge Structure

    International Nuclear Information System (INIS)

    Alp, E.E.; Mini, S.M.; Ramanathan, M.

    1990-04-01

    The x-ray absorption spectroscopy (XAS) had been an essential tool to gather spectroscopic information about atomic energy level structure in the early decades of this century. It has also played an important role in the discovery and systematization of rare-earth elements. The discovery of synchrotron radiation in 1952, and later the availability of broadly tunable synchrotron based x-ray sources have revitalized this technique since the 1970's. The correct interpretation of the oscillatory structure in the x-ray absorption cross-section above the absorption edge by Sayers et. al. has transformed XAS from a spectroscopic tool to a structural technique. EXAFS (Extended X-ray Absorption Fine Structure) yields information about the interatomic distances, near neighbor coordination numbers, and lattice dynamics. An excellent description of the principles and data analysis techniques of EXAFS is given by Teo. XANES (X-ray Absorption Near Edge Structure), on the other hand, gives information about the valence state, energy bandwidth and bond angles. Today, there are about 50 experimental stations in various synchrotrons around the world dedicated to collecting x-ray absorption data from the bulk and surfaces of solids and liquids. In this chapter, we will give the basic principles of XAS, explain the information content of essentially two different aspects of the absorption process leading to EXAFS and XANES, and discuss the source and samples limitations

  17. Neutron and X-ray Detectors

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-08-01

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

  18. X-ray Echo Spectroscopy

    Science.gov (United States)

    Shvyd'ko, Yuri

    2016-02-01

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

  19. Biometric identification using knee X-rays.

    Science.gov (United States)

    Shamir, Lior; Ling, Shari; Rahimi, Salim; Ferrucci, Luigi; Goldberg, Ilya G

    2009-01-01

    Identification of people often makes use of unique features of the face, fingerprints and retina. Beyond this, a similar identifying process can be applied to internal parts of the body that are not visible to the unaided eye. Here we show that knee X-rays can be used for the identification of individual persons. The image analysis method is based on the wnd-charm algorithm, which has been found effective for the diagnosis of clinical conditions of knee joints. Experimental results show that the rank-10 identification accuracy using a dataset of 425 individuals is ~56%, and the rank-1 accuracy is ~34%. The dataset contained knee X-rays taken several years apart from each other, showing that the identifiable features correspond to specific persons, rather than the present clinical condition of the joint.

  20. Imaging X-ray astronomy

    International Nuclear Information System (INIS)

    Elvis, M.

    1990-01-01

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

  1. Dental X-ray apparatus

    International Nuclear Information System (INIS)

    Weiss, M.E.

    1980-01-01

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

  2. X-ray fluorescence holography.

    Science.gov (United States)

    Hayashi, Kouichi; Happo, Naohisa; Hosokawa, Shinya; Hu, Wen; Matsushita, Tomohiro

    2012-03-07

    X-ray fluorescence holography (XFH) is a method of atomic resolution holography which utilizes fluorescing atoms as a wave source or a monitor of the interference field within a crystal sample. It provides three-dimensional atomic images around a specified element and has a range of up to a few nm in real space. Because of this feature, XFH is expected to be used for medium-range local structural analysis, which cannot be performed by x-ray diffraction or x-ray absorption fine structure analysis. In this article, we explain the theory of XFH including solutions to the twin-image problem, an advanced measuring system, and data processing for the reconstruction of atomic images. Then, we briefly introduce our recent applications of this technique to the analysis of local lattice distortions in mixed crystals and nanometer-size clusters appearing in the low-temperature phase of a shape-memory alloy.

  3. X-ray fluorescence holography

    International Nuclear Information System (INIS)

    Hayashi, Kouichi; Happo, Naohisa; Hosokawa, Shinya; Hu Wen; Matsushita, Tomohiro

    2012-01-01

    X-ray fluorescence holography (XFH) is a method of atomic resolution holography which utilizes fluorescing atoms as a wave source or a monitor of the interference field within a crystal sample. It provides three-dimensional atomic images around a specified element and has a range of up to a few nm in real space. Because of this feature, XFH is expected to be used for medium-range local structural analysis, which cannot be performed by x-ray diffraction or x-ray absorption fine structure analysis. In this article, we explain the theory of XFH including solutions to the twin-image problem, an advanced measuring system, and data processing for the reconstruction of atomic images. Then, we briefly introduce our recent applications of this technique to the analysis of local lattice distortions in mixed crystals and nanometer-size clusters appearing in the low-temperature phase of a shape-memory alloy. (topical review)

  4. X-ray scattering studies of surfaces and interfaces

    International Nuclear Information System (INIS)

    Sanyal, M.K.

    1998-01-01

    Here we shall briefly review the basics and some applications of x-ray specular reflectivity and diffuse scattering techniques. These x-ray scattering techniques are uniquely suited to study of the structure of surfaces and interfaces at atomic resolutions as they are nondestructive and can probe even interfaces which are buried. The study of structure of surfaces and interfaces is not only required in understanding physics in reduced dimensions but is also essential in developing technologically important materials

  5. Reduction of misclassification rates of obesity by body mass index using dual-energy X-ray absorptiometry scans to improve subsequent prediction of per cent fat mass in a Caucasian population

    DEFF Research Database (Denmark)

    Pedersen, Susie Dawn; Astrup, Arne; Skovgaard, Ib

    2011-01-01

    threshold, BMIT, was used ([BMIT = C/(0.75)3/2] for men and [BMIT = C/(0.65)3/2] for women). We conclude that simple formulae allow evaluation of fatness of individual patients more accurately than BMI, with the use of one baseline DXA scan, and enable the establishment of patient-specific obesity treatment...... threshold could be calculated (BMIT), above which the patient would be obese by %FM criteria. Data were collected from individuals who had a DXA scan as part of a nutritional research study at the University of Copenhagen. BMI incorrectly classified 48/329 (14.6%) of men and 52/589 (8.8%) of women......Recognition is increasing for the errors of body mass index (BMI) in classification of excess body fat. Dual-energy X-ray absorptiometry (DXA) is accurate to assess body fat mass per cent (%FM), but is underutilized clinically. We examined the prevalence of obesity misclassification by BMI...

  6. High frequency x-ray generator basics.

    Science.gov (United States)

    Sobol, Wlad T

    2002-02-01

    The purpose of this paper is to present basic functional principles of high frequency x-ray generators. The emphasis is put on physical concepts that determine the engineering solutions to the problem of efficient generation and control of high voltage power required to drive the x-ray tube. The physics of magnetically coupled circuits is discussed first, as a background for the discussion of engineering issues related to high-frequency power transformer design. Attention is paid to physical processes that influence such factors as size, efficiency, and reliability of a high voltage power transformer. The basic electrical circuit of a high frequency generator is analyzed next, with focus on functional principles. This section investigates the role and function of basic components, such as power supply, inverter, and voltage doubler. Essential electronic circuits of generator control are then examined, including regulation of voltage, current and timing of electrical power delivery to the x-ray tube. Finally, issues related to efficient feedback control, including basic design of the AEC circuitry are reviewed.

  7. X-ray Emission from Solar Flares

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... Solar flares; X-ray detectors; X-ray line emission and continuum; break energy; microflares. Abstract. Solar X-ray Spectrometer (SOXS), the first space-borne solar astronomy experiment of India was designed to improve our current understanding of X-ray emission from the Sun in general and solar flares in ...

  8. History of x-ray astronomy

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. History of x-ray astronomy. Major X-ray Missions. 1970 :UHURU: detected 339 new sources (1st sky coverage). 1978: Einstein First x-ray imaging mission (>1000 sources). 1990: ROSAT; Soft X-ray imaging mission; detected 100,000 sources (deeper sky coverage) ...

  9. X-Ray Exam: Cervical Spine

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español X-Ray Exam: Cervical Spine KidsHealth / For Parents / X-Ray ... MRI): Lumbar Spine Broken Bones Getting an X-ray (Video) X-Ray (Video) View more Partner Message About Us ...

  10. Chest X-Ray (Chest Radiography)

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Chest Chest x-ray uses a very ... limitations of Chest Radiography? What is a Chest X-ray (Chest Radiography)? The chest x-ray is the ...

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

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español X-Ray Exam: Neck KidsHealth / For Parents / X-Ray Exam: ... Neck Enlarged Adenoids Croup Sinusitis Getting an X-ray (Video) X-Ray (Video) View more Partner Message About Us ...

  12. Semiconductor X-ray spectrometers

    International Nuclear Information System (INIS)

    Muggleton, A.H.F.

    1978-02-01

    An outline is given of recent developments in particle and photon induced x-ray fluorescence (XRF) analysis. Following a brief description of the basic mechanism of semiconductor detector operation a comparison is made between semiconductor detectors, scintillators and gas filled proportional devices. Detector fabrication and cryostat design are described in more detail and the effects of various device parameters on system performance, such as energy resolution, count rate capability, efficiency, microphony, etc. are discussed. The main applications of these detectors in x-ray fluorescence analysis, electron microprobe analysis, medical and pollution studies are reviewed

  13. Portable X-Ray Device

    Science.gov (United States)

    1983-01-01

    Portable x-ray instrument developed by NASA now being produced commercially as an industrial tool may soon find further utility as a medical system. The instrument is Lixiscope - Low Intensity X-Ray Imaging Scope -- a self-contained, battery-powered fluoroscope that produces an instant image through use of a small amount of radioactive isotope. Originally developed by Goddard Space Flight Center, Lixiscope is now being produced by Lixi, Inc. which has an exclusive NASA license for one version of the device.

  14. Overutilization of x-rays

    International Nuclear Information System (INIS)

    Abrams, H.L.

    1979-01-01

    In this article on the overutilization of x-rays the author defines the term overutilization as excessive irradiation per unit of diagnostic information, therapeutic impact, or health outcome. Three main factors are described which lead to overutilization of x-rays: excessive radiation per film; excessive films per examination; and excessive examinations per patient. Topics discussed which influence the excessive examinations per patient are: the physician's lack of knowledge; undue dependence; lack of screening by radiologists; the physician's need for action and certainty; patient demand; reimbursement policies; institutional requirements; preventive medicine; defensive medicine; and the practice of radiology by nonradiologists

  15. X-ray data processing.

    Science.gov (United States)

    Powell, Harold R

    2017-10-31

    The method of molecular structure determination by X-ray crystallography is a little over a century old. The history is described briefly, along with developments in X-ray sources and detectors. The fundamental processes involved in measuring diffraction patterns on area detectors, i.e. autoindexing, refining crystal and detector parameters, integrating the reflections themselves and putting the resultant measurements on to a common scale are discussed, with particular reference to the most commonly used software in the field. © 2017 The Author(s).

  16. Tissue chemical analysis with muonic X-rays

    International Nuclear Information System (INIS)

    Hutson, R.L.; Reidy, J.J.; Springer, K.; Daniel, H.; Knowles, H.B.

    1976-01-01

    The stopped muon channel at the Clinton P. Anderson Meson Physics Facility (LAMPF) was used as a source of muons for studying the elemental composition of tissue with muonic X rays. The X ray spectra from several types of tissue were used to determine the amounts of carbon, nitrogen, and oxygen present. These determinations agree with the results of more conventional chemical analysis. The results show that muonic X rays offer a non-invasive technique for determining the amounts of the more abundant elements present in selected regions of the body. (orig.) [de

  17. A Solution to Hammer's X-ray Reconstruction Problem

    DEFF Research Database (Denmark)

    Gardner, Richard J.; Kiderlen, Markus

    2007-01-01

    We propose algorithms for reconstructing a planar convex body K from possibly noisy measurements of either its parallel X-rays taken in a fixed finite set of directions or its point X-rays taken at a fixed finite set of points, in known situations that guarantee a unique solution when the data is...... to K in the Hausdorff metric as k tends to infinity. This solves, for the first time in the strongest sense, Hammer’s X-ray problem published in 1963....

  18. Diamond x-ray optics: Transparent, resilient, high-resolution, and wavefront preserving

    International Nuclear Information System (INIS)

    Shvyd’ko, Yuri; Blank, Vladimir; Terentyev, Sergey

    2017-01-01

    Diamond features a unique combination of outstanding physical properties perfect for numerous x-ray optics applications, where traditional materials such as silicon fail to perform. In the last two decades, impressive progress has been achieved in synthesizing diamond with high crystalline perfection, in manufacturing efficient, resilient, high-resolution, wavefront-preserving diamond optical components, and in implementing them in cutting-edge x-ray instruments. Diamond optics are essential for tailoring x-rays to the most challenging needs of x-ray research. Furthermore, they are becoming vital for the generation of fully coherent hard x-rays by seeded x-ray free-electron lasers. In this article, we review progress in manufacturing flawless diamond crystal components and their applications in diverse x-ray optical devices, such as x-ray monochromators, beam splitters, high-reflectance backscattering mirrors, lenses, phase plates, diffraction gratings, bent-crystal spectrographs, and windows.

  19. X-ray microscopes at BESSY II

    International Nuclear Information System (INIS)

    Guttmann, P.; Niemann, B.; Thieme, J.; Wiesemann, U.; Rudolph, D.; Schmahl, G.

    2000-01-01

    The undulator U41 at BESSY II will be used as source for X-ray microscopes. An overview of the X-ray microscopy area is presented. After finishing the construction phase a transmission X-ray microscope, a scanning transmission X-ray microscope and an X-ray test chamber will be available. The transmission X-ray microscope will allow investigations with high lateral resolution at moderate energy resolution while the scanning transmission X-ray microscope will allow high energy resolution at moderate lateral resolution of the same specimen

  20. Nanoparticle-Assisted Scanning Focusing X-Ray Therapy with Needle Beam X Rays.

    Science.gov (United States)

    Davidson, R Andrew; Guo, Ting

    2016-01-01

    In this work, we show a new therapeutic approach using 40-120 keV X rays to deliver a radiation dose at the isocenter located many centimeters below the skin surface several hundred times greater than at the skin and how this dose enhancement can be augmented with nanomaterials to create several thousand-fold total dose enhancement effect. This novel approach employs a needle X-ray beam directed at the isocenter centimeters deep in the body while continuously scanning the beam to cover a large solid angle without overlapping at the skin. A Monte Carlo method was developed to simulate an X-ray dose delivered to the isocenter filled with X-ray absorbing and catalytic nanoparticles in a water phantom. An experimental apparatus consisting of a moving plastic phantom irradiated with a stationary 1 mm needle X-ray beam was built to test the theoretical predictions. X-ray films were used to characterize the dose profiles of the scanning X-ray apparatus. Through this work, it was determined that the X-ray dose delivered to the isocenter in a treatment voxel (t-voxel) underneath a 5 cm deep high-density polyethylene (HDPE) phantom was 295 ± 48 times greater than the surface dose. This measured value was in good agreement with the theoretical predicted value of 339-fold. Adding X-ray-absorbing nanoparticles, catalytic nanoparticles or both into the t-voxel can further augment the dose enhancement. For example, we predicted that adding 1 weight percentage (wp) of gold into water could increase the effective dose delivered to the target by onefold. Dose enhancement using 1 mm X-ray beam could reach about 1,600-fold in the t-voxel when 7.5 wp of 88 nm diameter silica-covered gold nanoparticles were added, which we showed in a previously published study can create a dose enhancement of 5.5 ± 0.46-fold without scanning focusing enhancement. Based on the experimental data from that study, mixing 0.02 wp 2.5 nm diameter small tetrakis hydroxymethyl phosphonium chloride (THPC

  1. Comparison of multi- and single-frequency bioelectrical impedance analysis with dual-energy X-ray absorptiometry for assessment of body composition in post-menopausal women: effects of body mass index and accelerometer-determined physical activity.

    Science.gov (United States)

    Gába, A; Kapuš, O; Cuberek, R; Botek, M

    2015-08-01

    Bioelectric impedance analysis (BIA) is commonly used in research to assess body composition. However, studies that validate the accuracy of BIA exclusively in post-menopausal women are lacking. The main purpose of the present study was to evaluate the agreement of multi-frequency (MF)-BIA and single-frequency (SF)-BIA with dual-energy X-ray absorptiometry (DXA) in the estimation of fat mass (FM) and fat-free mass (FFM) among post-menopausal women with variation in body mass index (BMI) and physical activity (PA). FM and FFM were estimated by BIA and DXA in 146 post-menopausal women with a mean (SD) age of 62.8 (5.2) years. PA was determined by an accelerometer. The mean (SD) difference between MF-BIA and DXA was -1.8 (1.8) kg (P = 0.08) and 1.3 (1.8) kg (P = 0.01) for FM and FFM, respectively. SF-BIA provided a significantly lower estimate of FM [-2.0 (2.2) kg; P = 0.04] and a higher estimate of FFM [1.8 (2.4) kg; P obese and insufficiently active subjects. In other BMI and PA groups, both BIA devices showed a similar deviation from DXA. BIA tends to underestimate FM and overestimate FFM relative to DXA. MF-BIA appears to be a more appropriate method for the assessment of body composition than SF-BIA in post-menopausal woman with BMI >30 kg/m(2) and in those who are insufficiently active. © 2014 The British Dietetic Association Ltd.

  2. Illumination system for X-ray lithography

    International Nuclear Information System (INIS)

    Buckley, W.D.

    1989-01-01

    An X-ray lithography system is described, comprising: a point source of X-Ray radiation; a wafer plane disposed in spaced relation to the point source of X-Ray radiation; a mask disposed between the point source of X-Ray radiation and the wafer plane whereby X-Ray radiation from the point source of X-ray radiation passes through the mask to the water plane; and X-Ray absorbent means mounted between the point source of X-Ray radiation and the wafer plane, the X-Ray absorbent means being of quadratically absorption from maximum absorption at the center to minimum absorption at the edge so as to have a radial absorption gradient profile to compensate for radial flux variation of the X-Ray radiation

  3. Archimedes Manuscript under X-ray Vision

    International Nuclear Information System (INIS)

    Bergmann, Uwe

    2006-01-01

    Archimedes of Syracuse (287 - 212 BC) is considered one of the most brilliant thinkers of all times. The 10th century parchment document known as the Archimedes Palimpsest is the unique source for two of the Greek's treatises - the Stomachion, and The Method of Mechanical Theorems. It is also the only source for On Floating Bodies in Greek. The privately owned palimpsest is the subject of an integrated campaign of conservation, imaging, and scholarship being undertaken at the Walters Art Museum in Baltimore. Much of the text has been imaged by various optical techniques, but significant gaps remain in our knowledge of the writings of Archimedes, while texts by other authors - potentially of major significance - remain yet unread. A breakthrough in uncovering the missing Archimedes writings has recently been achieved at the Stanford Synchrotron Radiation Laboratory. Using x-ray fluorescence imaging, writings from faint traces of the partly erased iron gall ink were brought to light. The x-ray image revealed Archimedes writings from some of his most important works covered by 12th century biblical texts and 20th century gold forgeries. Please join me in a fascinating journey of a 1000 year old parchment from its origin in the Mediterranean city of Constantinople to an x-ray beam line in Menlo Park, California.

  4. Autoradiographic studies of cell kinetics after whole body x-ray irradiation. Part 2. Postradiation death of differentiating and proliferating subependymal cells in rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Gracheva, N.D.

    1982-03-01

    Post-radiation cell death in the subependymal zone of the rat brain was investigated by injection of /sub 3/H-thymidine 60 to 80 min prior to x-ray irradiation of the animals with 50, 150, or 300 R. Subsequent correlation of autoradiographic findings with the cell cycle showed that the proliferating and differentiating (D) cells followed a fluctuating pattern in cell death, in that cells irradiated in the early G/sub 2/ and the S phases showed four peaks of mitotic cell death in the first postradiation cell cycle. Cells injured in the G/sub 1/ phase lost the capacity for DNA synthesis, since the 300 R-irradiated cells failed to incorporate /sup 14/C-thymidine administered subsequently (3 H before sacrifice, 12 to 17 h after /sup 3/H-thymidine injection). Since these cells did not die within 4 h of irradiation, their death evidently came about during the first postradiation cell cycle. The cell death pattern of the D cells coincided with the death peaks and mitotic peaks of the proliferating cells, indicating that the D cells retained the rhythm and phase sequence of the mitotic cycle in the form of a short cycle. All the irradiated cells entered mitosis with a one hour delay, and the total number of cell deaths was dosage-related. 11 references, 4 figures.

  5. Bone X-Ray (Radiography)

    Medline Plus

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

  6. X-ray tube transformer

    International Nuclear Information System (INIS)

    1980-01-01

    An X-ray generator is described which comprises a transmission line transformer including an electrical conductor with a cavity and a second electrical conductor including helical windings disposed along a longitudinal axis within the cavity of the first conductor. The windings have a pitch which varies per unit length along the axis. There is dielectric material in the cavity for insulation and to couple electromagnetically the two conductors in response to an electric current flowing through the conductors, which have an impedance between them; this varies with distance along the axis of the helix of the second conductor. An X-ray tube is disposed along the longitudinal axis within the cavity, for radiating X-rays. The invention increases the voltage of applied voltage pulses at the remote tube-head with a transformer formed by using a spiral delay line geometry to give a tapered-impedance coaxial high voltage multiplier for pulse voltage operation. This transformer is smaller and lighter than previous designs for the same high peak voltage and power ratings. This is important because the penetration capabilities of Flash X-ray equipment increase with voltage, particularly in heavy materials such as steel. (U.K.)

  7. X-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Vries, J.L. de.

    1976-01-01

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

  8. X-Ray Diffractive Optics

    Science.gov (United States)

    Dennis, Brian; Li, Mary; Skinner, Gerald

    2013-01-01

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

  9. X-rays from stars

    Science.gov (United States)

    Güdel, Manuel

    2004-07-01

    Spectroscopic studies available from Chandra and XMM-Newton play a pivotal part in the understanding of the physical processes in stellar (magnetic and non-magnetic) atmospheres. It is now routinely possible to derive densities and to study the influence of ultraviolet radiation fields, both of which can be used to infer the geometry of the radiating sources. Line profiles provide important information on bulk mass motions and attenuation by neutral matter, e.g. in stellar winds. The increased sensitivity has revealed new types of X-ray sources in systems that were thought to be unlikely places for X-rays: flaring brown dwarfs, including rather old, non-accreting objects, and terminal shocks in jets of young stars are important examples. New clues concerning the role of stellar high-energy processes in the modification of the stellar environment (ionization, spallation, etc.) contribute significantly to our understanding of the "astro-ecology" in forming planetary systems. Technological limitations are evident. The spectral resolution has not reached the level where bulk mass motions in cool stars become easily measurable. Higher resolution would also be important to perform X-ray "Doppler imaging" in order to reconstruct the 3-D distribution of the X-ray sources around a rotating star. Higher sensitivity will be required to perform high-resolution spectroscopy of weak sources such as brown dwarfs or embedded pre-main-sequence sources. A new generation of satellites such as Constellation-X or XEUS should pursue these goals.

  10. High resolution X ray spectroscopy

    International Nuclear Information System (INIS)

    Bartiromo, R.

    1987-01-01

    This paper is devoted to a detailed discussion of the physical processes which are responsible for the emission spectra of H-like and He-like ion of high Z impurities in low density plasmas. The application of high resolution X-ray spectroscopy to the diagnostic of tokamak plasmas is also discussed and examples of the results obtained are presented

  11. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... An x-ray (radiograph) is a noninvasive medical test that helps physicians diagnose and treat medical conditions. ...

  12. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the equipment look like? How does the procedure work? How is the procedure performed? What will I experience during and after the procedure? Who interprets the results and how do I get them? What are the benefits vs. risks? What are the limitations of Bone X-ray ( ...

  13. Bone X-Ray (Radiography)

    Medline Plus

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

  14. X-ray image coding

    International Nuclear Information System (INIS)

    1974-01-01

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

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... any possibility that they are pregnant. Many imaging tests are not performed during pregnancy so as not to expose the fetus to ... See the Safety page for more information about pregnancy and x-rays. A Word About Minimizing ... imaging tests and treatments have special pediatric considerations. The teddy ...

  16. X-rays and magnetism

    International Nuclear Information System (INIS)

    Fischer, Peter; Ohldag, Hendrik

    2015-01-01

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

  17. Bone X-Ray (Radiography)

    Medline Plus

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

  18. Stellar X-Ray Polarimetry

    Science.gov (United States)

    Swank, J.

    2011-01-01

    Most of the stellar end-state black holes, pulsars, and white dwarfs that are X-ray sources should have polarized X-ray fluxes. The degree will depend on the relative contributions of the unresolved structures. Fluxes from accretion disks and accretion disk corona may be polarized by scattering. Beams and jets may have contributions of polarized emission in strong magnetic fields. The Gravity and Extreme Magnetism Small Explorer (GEMS) will study the effects on polarization of strong gravity of black holes and strong magnetism of neutron stars. Some part of the flux from compact stars accreting from companion stars has been reflected from the companion, its wind, or accretion streams. Polarization of this component is a potential tool for studying the structure of the gas in these binary systems. Polarization due to scattering can also be present in X-ray emission from white dwarf binaries and binary normal stars such as RS CVn stars and colliding wind sources like Eta Car. Normal late type stars may have polarized flux from coronal flares. But X-ray polarization sensitivity is not at the level needed for single early type stars.

  19. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... time. Follow-up examinations are sometimes the best way to see if treatment is working or if a finding is stable or changed over time. top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and easiest way for a ...

  20. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos ... to current x-ray images for diagnosis and disease management. top of page How is the procedure ...

  1. X-ray absorption holography

    Czech Academy of Sciences Publication Activity Database

    Kopecký, Miloš; Lausi, A.; Bussetto, E.; Kub, Jiří; Savoia, A.

    2002-01-01

    Roč. 88, č. 18 (2002), s. 185503-1 - 185503-3 ISSN 0031-9007 R&D Projects: GA MŠk LN00A100 Institutional research plan: CEZ:AV0Z1010921 Keywords : x-ray holography Subject RIV: BH - Optics, Masers, Lasers Impact factor: 7.323, year: 2002

  2. Compact x-ray source and panel

    Science.gov (United States)

    Sampayon, Stephen E [Manteca, CA

    2008-02-12

    A compact, self-contained x-ray source, and a compact x-ray source panel having a plurality of such x-ray sources arranged in a preferably broad-area pixelized array. Each x-ray source includes an electron source for producing an electron beam, an x-ray conversion target, and a multilayer insulator separating the electron source and the x-ray conversion target from each other. The multi-layer insulator preferably has a cylindrical configuration with a plurality of alternating insulator and conductor layers surrounding an acceleration channel leading from the electron source to the x-ray conversion target. A power source is connected to each x-ray source of the array to produce an accelerating gradient between the electron source and x-ray conversion target in any one or more of the x-ray sources independent of other x-ray sources in the array, so as to accelerate an electron beam towards the x-ray conversion target. The multilayer insulator enables relatively short separation distances between the electron source and the x-ray conversion target so that a thin panel is possible for compactness. This is due to the ability of the plurality of alternating insulator and conductor layers of the multilayer insulators to resist surface flashover when sufficiently high acceleration energies necessary for x-ray generation are supplied by the power source to the x-ray sources.

  3. Development of Compton X-ray spectrometer for high energy resolution single-shot high-flux hard X-ray spectroscopy.

    Science.gov (United States)

    Kojima, Sadaoki; Ikenouchi, Takahito; Arikawa, Yasunobu; Sakata, Shohei; Zhang, Zhe; Abe, Yuki; Nakai, Mitsuo; Nishimura, Hiroaki; Shiraga, Hiroyuki; Ozaki, Tetsuo; Miyamoto, Shuji; Yamaguchi, Masashi; Takemoto, Akinori; Fujioka, Shinsuke; Azechi, Hiroshi

    2016-04-01

    Hard X-ray spectroscopy is an essential diagnostics used to understand physical processes that take place in high energy density plasmas produced by intense laser-plasma interactions. A bundle of hard X-ray detectors, of which the responses have different energy thresholds, is used as a conventional single-shot spectrometer for high-flux (>10(13) photons/shot) hard X-rays. However, high energy resolution (Δhv/hv spectrometer because its energy resolution is limited by energy differences between the response thresholds. Experimental demonstration of a Compton X-ray spectrometer has already been performed for obtaining higher energy resolution than that of DET spectrometers. In this paper, we describe design details of the Compton X-ray spectrometer, especially dependence of energy resolution and absolute response on photon-electron converter design and its background reduction scheme, and also its application to the laser-plasma interaction experiment. The developed spectrometer was used for spectroscopy of bremsstrahlung X-rays generated by intense laser-plasma interactions using a 200 μm thickness SiO2 converter. The X-ray spectrum obtained with the Compton X-ray spectrometer is consistent with that obtained with a DET X-ray spectrometer, furthermore higher certainly of a spectral intensity is obtained with the Compton X-ray spectrometer than that with the DET X-ray spectrometer in the photon energy range above 5 MeV.

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

    NARCIS (Netherlands)

    Groot, F.M.F. de

    2000-01-01

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

  5. X-Ray Optics for the 2020's

    Science.gov (United States)

    Zhang, Will

    2010-01-01

    X-ray optics is an essential and enabling technology for x-ray astronomy. This slide presentation presents the authors views on the requirements for x-ray optics as progress is made toward building IXO and preparing for the 2020's. The presentation reviews the status of several technologies that are being developed and outlines the steps that we as a community needs to take to move toward x-ray optics meeting the five key requirements: (1) high angular resolution, (2) large effective area, (3) low mass, (4) fast production, and (5) low cost. There is discussion of segmentation vs full shell, size of the mirror segment, mirror segment frabrication, post-slumping figure improvement, and characterization of coating quality.

  6. Normative values for CT-based texture analysis of vertebral bodies in dual X-ray absorptiometry-confirmed, normally mineralized subjects

    Energy Technology Data Exchange (ETDEWEB)

    Mannil, Manoj; Eberhard, Matthias; Becker, Anton S.; Alkadhi, Hatem; Guggenberger, Roman [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Schoenenberg, Denise; Osterhoff, Georg [University Hospital Zurich, Division of Trauma Surgery, Zurich (Switzerland); Frey, Diana P. [University Hospital Zurich, Department of Rheumatology, Zurich (Switzerland); Konukoglu, Ender [Computer Vision Laboratory, Department of Information Technology and Electrical Engineering, Zurich (Switzerland)

    2017-11-15

    To develop age-, gender-, and regional-specific normative values for texture analysis (TA) of spinal computed tomography (CT) in subjects with normal bone mineral density (BMD), as defined by dual X-ray absorptiometry (DXA), and to determine age-, gender-, and regional-specific differences. In this retrospective, IRB-approved study, TA was performed on sagittal CT bone images of the thoracic and lumbar spine using dedicated software (MaZda) in 141 individuals with normal DXA BMD findings. Numbers of female and male subjects were balanced in each of six age decades. Three hundred and five TA features were analyzed in thoracic and lumbar vertebrae using free-hand regions-of-interest. Intraclass correlation (ICC) coefficients were calculated for determining intra- and inter-observer agreement of each feature. Further dimension reduction was performed with correlation analyses. The TA features with an ICC < 0.81 indicating compromised intra- and inter-observer agreement and with Pearson correlation scores r > 0.8 with other features were excluded from further analysis for dimension reduction. From the remaining 31 texture features, a significant correlation with age was found for the features mean (r = -0.489, p < 0.001), variance (r = -0.681, p < 0.001), kurtosis (r = 0.273, p < 0.001), and WavEnLL{sub s}4 (r = 0.273, p < 0.001). Significant differences were found between genders for various higher-level texture features (p < 0.001). Regional differences among the thoracic spine, thoracic-lumbar junction, and lumbar spine were found for most TA features (p < 0.021). This study established normative values of TA features on CT images of the spine and showed age-, gender-, and regional-specific differences in individuals with normal BMD as defined by DXA. (orig.)

  7. Comparisons between Hologic, Lunar and Norland dual-energy X-ray absorptiometers and other techniques used for whole-body soft tissue measurements.

    Science.gov (United States)

    Tothill, P; Avenell, A; Love, J; Reid, D M

    1994-11-01

    Assessment of the precision and accuracy of dual-energy X-ray absorptiometers (DXA) from three manufacturers, used for measuring soft-tissue composition, and comparability with each other and other techniques. Measurements of an anthropomorphic model of variable composition and thickness. 11 volunteers measured with each instrument and by underwater weighing (UWW) and three brands of bioelectric impedance analysis (BIA) apparatus. New software, introduced by each manufacturer during the course of the investigation, led to changes in measured fat proportion. The precision of determination of fat proportion by DXA in the (small) model was 3-4% (coefficient of variation), with little difference between brands. In vivo precision was 2-3%. In the model, measurements of % fat differed from the nominal values, but variation with thickness was small. There were significant mean differences of total fat proportion in the volunteers between pairs of DXA instruments of 2.6-6.3% fat. The SDs of the differences were 1.8-2.9% fat. Regional differences were greater, with trunk % fat being particularly underestimated by Hologic relative to Lunar and Norland. Compared with UWW, mean % fat was the same for Hologic, but higher for Lunar and Norland. SDs of 4% demonstrated inadequate agreement. The differences varied with proportion of bone in lean tissue, questioning the assumption of constant density of lean tissue in UWW. There were no mean differences of % fat between the BIA instruments and DXA and UWW, but SDs of 3-6% suggest that BIA using these instruments does not offer an acceptable accuracy in estimating fat proportion. UWW has limitations as a reference method. DXA is a useful technique, but its limitations, particularly regarding assumptions about fat distribution, must be borne in mind. The differences of fat proportion recorded by the three DXA instruments are such as to preclude interchangeability in measurements of individual subjects or in clinical trials.

  8. Normative values for CT-based texture analysis of vertebral bodies in dual X-ray absorptiometry-confirmed, normally mineralized subjects

    International Nuclear Information System (INIS)

    Mannil, Manoj; Eberhard, Matthias; Becker, Anton S.; Alkadhi, Hatem; Guggenberger, Roman; Schoenenberg, Denise; Osterhoff, Georg; Frey, Diana P.; Konukoglu, Ender

    2017-01-01

    To develop age-, gender-, and regional-specific normative values for texture analysis (TA) of spinal computed tomography (CT) in subjects with normal bone mineral density (BMD), as defined by dual X-ray absorptiometry (DXA), and to determine age-, gender-, and regional-specific differences. In this retrospective, IRB-approved study, TA was performed on sagittal CT bone images of the thoracic and lumbar spine using dedicated software (MaZda) in 141 individuals with normal DXA BMD findings. Numbers of female and male subjects were balanced in each of six age decades. Three hundred and five TA features were analyzed in thoracic and lumbar vertebrae using free-hand regions-of-interest. Intraclass correlation (ICC) coefficients were calculated for determining intra- and inter-observer agreement of each feature. Further dimension reduction was performed with correlation analyses. The TA features with an ICC < 0.81 indicating compromised intra- and inter-observer agreement and with Pearson correlation scores r > 0.8 with other features were excluded from further analysis for dimension reduction. From the remaining 31 texture features, a significant correlation with age was found for the features mean (r = -0.489, p < 0.001), variance (r = -0.681, p < 0.001), kurtosis (r = 0.273, p < 0.001), and WavEnLL s 4 (r = 0.273, p < 0.001). Significant differences were found between genders for various higher-level texture features (p < 0.001). Regional differences among the thoracic spine, thoracic-lumbar junction, and lumbar spine were found for most TA features (p < 0.021). This study established normative values of TA features on CT images of the spine and showed age-, gender-, and regional-specific differences in individuals with normal BMD as defined by DXA. (orig.)

  9. X-ray cardiovascular examination apparatus

    International Nuclear Information System (INIS)

    1977-01-01

    An X-ray source is mounted in an enclosure for angulating longitudinally about a horizontal axis. An X-ray-permeable, patient-supporting table is mounted on the top of the enclosure for executing lateral and longitudinal movements. An X-ray image-receiving device such as an X-ray image intensifier is mounted above the table on a vertically movable arm which is on a longitudinally movable carriage. Electric control means are provided for angulating the X-ray source and image intensifier synchronously as the image intensifier system is shifted longitudinally or vertically such that the central ray from the X-ray source is kept intensifier

  10. Effective X-ray beam size measurements of an X-ray tube and polycapillary X-ray lens system using a scanning X-ray fluorescence method

    Energy Technology Data Exchange (ETDEWEB)

    Gherase, Mihai R., E-mail: mgherase@csufresno.edu; Vargas, Andres Felipe

    2017-03-15

    Size measurements of an X-ray beam produced by an integrated polycapillary X-ray lens (PXL) and X-ray tube system were performed by means of a scanning X-ray fluorescence (SXRF) method using three different metallic wires. The beam size was obtained by fitting the SXRF data with the analytical convolution between a Gaussian and a constant functions. For each chemical element in the wire an effective energy was calculated based on the incident X-ray spectrum and its photoelectric cross section. The proposed method can be used to measure the effective X-ray beam size in XRF microscopy studies.

  11. Center for X-Ray Optics, 1986

    International Nuclear Information System (INIS)

    1987-07-01

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

  12. X-ray diagnostic in gas discharge

    International Nuclear Information System (INIS)

    Chen Suhe; Wang Dalun; Cui Gaoxian; Wang Mei; Fu Yibei; Zhang Xinwei; Zhang Wushou

    1995-01-01

    X rays were observed when the anomalous phenomenon in the metal loaded with deuterium studied by the gas-discharge method. Therefore the X-ray energy spectra were measured by the absorption method, the specific X-ray approach and the NaI scintillation counter, while X-ray intensity was estimated by using 7 Li thermoluminescent foils. The X-ray average energy measured by the absorption method is 27.6 +- 2.1 keV, which is fitted within the error extent to 26.0 +-2.4 keV monoenergetic X rays measured by the NaI scintillation counter

  13. Relationships among dual-energy X-ray absorptiometry (DXA), bioelectrical impedance (BIA), and ultrasound measurements of body composition of swine

    Science.gov (United States)

    In three separate studies (156 pigs total), DXA, BIA, and ultrasound were compared as methods for measuring live body composition of pigs at 60 and 100-110 kg BWt. DXA measured total body fat and lean content, BIA measurements of resistance (Rs) and reactance (Xc) were used to calculate total body l...

  14. X-ray tube arrangements

    International Nuclear Information System (INIS)

    Gillard, R.G.

    1980-01-01

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

  15. X-ray Sensitive Material

    Science.gov (United States)

    2015-12-01

    Reference 3), inorganic semiconductors (silicon [Si], cadmium zinc telluride [CdZnTe]) (Reference 4) and selenium (References 5 and 6), Ne-Xe...data showing photocurrent generation. Reports on other X-ray photoconductors, such as amorphous selenium , typically show such data (Reference 34). We...that BiI3 content does contribute to surface discharge; however, further work is warranted to measure the photocurrent. Selenium films used for

  16. Diffractive X-ray Telescopes

    OpenAIRE

    Skinner, Gerald K.

    2010-01-01

    Diffractive X-ray telescopes using zone plates, phase Fresnel lenses, or related optical elements have the potential to provide astronomers with true imaging capability with resolution several orders of magnitude better than available in any other waveband. Lenses that would be relatively easy to fabricate could have an angular resolution of the order of micro-arc-seconds or even better, that would allow, for example, imaging of the distorted space- time in the immediate vicinity of the super...

  17. Smart X-ray optics

    International Nuclear Information System (INIS)

    Michette, A G; Pfauntsch, S J; Sahraei, S; Shand, M; Morrison, G R; Hart, D; Vojnovic, B; Stevenson, T; Parkes, W; Dunare, C; Willingale, R; Feldman, C; Button, T; Zhang, D; Rodriguez-Sanmartin, D; Wang, H

    2009-01-01

    This paper describes reflective adaptive/active optics for applications including studies of biological radiation damage. The optics work on the polycapillary principle, but use arrays of channels in thin silicon. For optimum performance the x-rays should reflect once off a channel wall in each of two successive arrays. This reduces aberrations since then the Abbe sine condition is approximately satisfied. Adaptivity is achieved by flexing the arrays via piezo actuation, providing further aberration reduction and controllable focal length.

  18. X-ray Characterization of Materials

    Science.gov (United States)

    Lifshin, Eric

    1999-09-01

    Linking of materials properties with microstructures is a fundamental theme in materials science, for which a detailed knowledge of the modern characterization techniques is essential. Since modern materials such as high-temperature alloys, engineering thermoplastics and multilayer semiconductor films have many elemental constituents distributed in more than one phase, characterization is essential to the systematic development of such new materials and understanding how they behave in practical applications. X-ray techniques play a major role in providing information on the elemental composition and crystal and grain structures of all types of materials. The challenge to the materials characterization expert is to understand how specific instruments and analytical techniques can provide detailed information about what makes each material unique. The challenge to the materials scientist, chemist, or engineer is to know what information is needed to fully characterize each material and how to use this information to explain its behavior, develop new and improved properties, reduce costs, or ensure compliance with regulatory requirements. This comprehensive handbook presents all the necessary background to understand the applications of X-ray analysis to materials characterization with particular attention to the modern approach to these methods.

  19. Methods of X-ray examination of condylar knee replacement

    International Nuclear Information System (INIS)

    Vavrik, P.

    1988-01-01

    A detailed description is presented of the methodology of X-ray examination of patients with a condylar knee replacement. Preoperative examination includes standard anterio-posterior and lateral projections, axial projection of the patella in 30 deg flexion of the knee, examination of the mechanical axis of the extremity on a 90 x 30 format and the radioscopic assessment of the centre of the hip joint, essential for the correct centering of the knee implant. Immediately after surgery the position of the implant is checked in two standard projections. Another X-ray check is made after six weeks, before partial loading of the joint is permitted. A complete X-ray examination is made prior to the full loading of the knee joint. The methods are also discussed of the X-ray evaluation of complications such as aseptic loosening of the components, infection, instability, fractures. The general solution od these problems is described. The necessity is underlined of the deliberate and qualified indication of X-ray examinations. The basic prerequisites are listed for reducing the present considerable radiation burden of these patients in the course of the many X-ray examinations. (author). 7 figs., 3 tab., 6 refs

  20. Femtosecond profiling of shaped x-ray pulses

    Science.gov (United States)

    Hoffmann, M. C.; Grguraš, I.; Behrens, C.; Bostedt, C.; Bozek, J.; Bromberger, H.; Coffee, R.; Costello, J. T.; DiMauro, L. F.; Ding, Y.; Doumy, G.; Helml, W.; Ilchen, M.; Kienberger, R.; Lee, S.; Maier, A. R.; Mazza, T.; Meyer, M.; Messerschmidt, M.; Schorb, S.; Schweinberger, W.; Zhang, K.; Cavalieri, A. L.

    2018-03-01

    Arbitrary manipulation of the temporal and spectral properties of x-ray pulses at free-electron lasers would revolutionize many experimental applications. At the Linac Coherent Light Source at Stanford National Accelerator Laboratory, the momentum phase-space of the free-electron laser driving electron bunch can be tuned to emit a pair of x-ray pulses with independently variable photon energy and femtosecond delay. However, while accelerator parameters can easily be adjusted to tune the electron bunch phase-space, the final impact of these actuators on the x-ray pulse cannot be predicted with sufficient precision. Furthermore, shot-to-shot instabilities that distort the pulse shape unpredictably cannot be fully suppressed. Therefore, the ability to directly characterize the x-rays is essential to ensure precise and consistent control. In this work, we have generated x-ray pulse pairs via electron bunch shaping and characterized them on a single-shot basis with femtosecond resolution through time-resolved photoelectron streaking spectroscopy. This achievement completes an important step toward future x-ray pulse shaping techniques.

  1. Aspergillosis - chest x-ray (image)

    Science.gov (United States)

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

  2. Soft x-ray Planetary Imager

    Data.gov (United States)

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

  3. Stabilized x-ray generator power supply

    International Nuclear Information System (INIS)

    Saha, Subimal; Purushotham, K.V.; Bose, S.K.

    1986-01-01

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

  4. X-ray electromagnetic application technology

    International Nuclear Information System (INIS)

    2011-01-01

    The investigating committee aimed at research on electromagnetic fields in functional devices and X-ray fibers for efficient coherent X-ray generation and their material science, high-precision manufacturing, particularly for X-ray electromagnetic application technology from January 2006 to December 2008. In this report, we describe our research results, in particular, on the topics of synchrotron radiation and free-electron laser, Saga Synchrotron Project, X-ray waveguides and waveguide-based lens-less hard-X-ray imaging, X-ray nanofocusing for capillaries and zone plates, dispersion characteristics in photonics crystal consisting of periodic atoms for nanometer waveguides, electromagnetic characteristics of grid structures for scattering fields of nano-meter electromagnetic waves and X-rays, FDTD parallel computing of fundamental scattering and attenuation characteristics of X-ray for medical imaging diagnosis, orthogonal relations of electromagnetic fields including evanescent field in dispersive medium. (author)

  5. Development of quantitative x-ray microtomography

    International Nuclear Information System (INIS)

    Deckman, H.W.; Dunsmuir, J.A.; D'Amico, K.L.; Ferguson, S.R.; Flannery, B.P.

    1990-01-01

    The authors have developed several x-ray microtomography systems which function as quantitative three dimensional x-ray microscopes. In this paper the authors describe the evolutionary path followed from making the first high resolution experimental microscopes to later generations which can be routinely used for investigating materials. Developing the instrumentation for reliable quantitative x-ray microscopy using synchrotron and laboratory based x-ray sources has led to other imaging modalities for obtaining temporal and spatial two dimensional information

  6. X-ray fluorescence with synchrotron radiation

    International Nuclear Information System (INIS)

    Raman, S.; Sparks, C.J. Jr.

    1978-01-01

    An experimental set-up for x-ray fluorescence analysis with synchrotron radiation was built and installed at the Stanford Synchrotron Radiation Project. X-ray spectra were taken from numerous and varied samples in order to assess the potential of synchrotron radiation as an excitation source for multielement x-ray fluorescence analysis. For many applications, the synchrotron radiation technique is shown to be superior to other x-ray fluorescence methods, especially those employing electrons and protons as excitation sources

  7. Phase-sensitive X-ray imager

    Science.gov (United States)

    Baker, Kevin Louis

    2013-01-08

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

  8. Element specific X-ray fluorescene microtomography

    OpenAIRE

    Günzler, Til Florian

    2003-01-01

    X-ray fluorescence is widely known as an element-specific scanning analytic tool. It is used in many fields of science and technology and has given major new insights into different problems. The relatively large penetration depth of x rays into matter makes them ideally suited for tomography. The combination of x-ray fluorescence analysis and scanning microtomography, hereafter called x-ray fluorescence microtomography, has been further developed and improved in this work. Employing the newl...

  9. X-ray diagnostics - benefits and risks

    International Nuclear Information System (INIS)

    Bartholomaeus, Melanie

    2016-01-01

    The brochure on benefits and risks of X-ray diagnostics discusses the following issues: X radiation - a pioneering discovery and medical sensation, fundamentals of X radiation, frequency of X-ray examinations in Germany in relation to CT imaging, radiation doses resulting from X-ray diagnostics, benefits of X-ray diagnostics - indication and examples, risks - measures for radiation exposure reductions, avoidance of unnecessary examinations.

  10. Should we X-ray Halloween candy? Revisited.

    Science.gov (United States)

    Calvanese, J

    1988-04-01

    The well-intentioned program of X-raying Halloween candy is costly. The annual expense to the 3 local hospitals in the Reno/Sparks area was $1625.62. The price to X-ray each bag ranged from $2.01 to $5.23 (average $3.38). On the basis of our total regional population statistics, the nation could be spending as much as $0.8-$1.4 million to screen Halloween candy. Radiographic screening of Halloween candy is not effective. Of the 394 X-rays taken in the 3 local hospitals, and the 669 taken in 18 outlying hospitals, no films were positive for hidden radio-opaque forein bodies. Not only is X-raying Halloween candy costly and ineffective, it also creates several problems. Children taking their candy to the hospital on Halloween night risk involvement in traffic accidents. The implication that X-rayed candy is "safe" carries potential liability. Additional drawbacks and risks arise from crowds composed mostly of children in the Radiology Dept and Emergency Room, and from disruption of vital hospital functions. In October, 1986, a program for community education and cooperation among all 3 area hospitals was developed. No X-rays were offered in the Reno/Sparks area. There were no police reports of contaminated candy for this Halloween following implementation of this program, compared to 4 reports for the preceding 2 years.

  11. The Beginnings of X-ray Crystallography

    Indian Academy of Sciences (India)

    IAS Admin

    The Beginnings of X-ray Crystallography. A Profile on the Two Braggs. Those were the days when Science was hovering around the wave–particle duality. William. Henry Bragg was toying with the idea that X-rays are particles and the observation made by Max von Laue that X-rays are diffracted by crystals could indeed ...

  12. Center for X-ray Optics, 1988

    Energy Technology Data Exchange (ETDEWEB)

    1989-04-01

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

  13. X-Ray Exam: Femur (Upper Leg)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español X-Ray Exam: Femur (Upper Leg) KidsHealth / For Parents / X- ... Muscles, and Joints Broken Bones Getting an X-ray (Video) X-Ray (Video) View more Partner Message About Us ...

  14. X-Rays, Pregnancy and You

    Science.gov (United States)

    ... Emitting Products and Procedures Medical Imaging Medical X-ray Imaging X-Rays, Pregnancy and You Share Tweet Linkedin Pin it ... the decision with your doctor. What Kind of X-Rays Can Affect the Unborn Child? During most x- ...

  15. X-Ray Exam: Scoliosis (For Parents)

    Science.gov (United States)

    ... for Educators Search English Español X-Ray Exam: Scoliosis KidsHealth / For Parents / X-Ray Exam: Scoliosis What's in this article? What It Is Why ... You Have Questions Print What It Is A scoliosis X-ray is a relatively safe and painless ...

  16. Cryotomography x-ray microscopy state

    Science.gov (United States)

    Le Gros, Mark; Larabell, Carolyn A.

    2010-10-26

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

  17. Student X-Ray Fluorescence Experiments

    Science.gov (United States)

    Fetzer, Homer D.; And Others

    1975-01-01

    Describes the experimental arrangement for x-ray analysis of samples which involves the following: the radioisotopic x-ray disk source; a student-built fluorescence chamber; the energy dispersive x-ray detector, linear amplifier and bias supply; and a multichannel pulse height analyzer. (GS)

  18. Electron beam parallel X-ray generator

    Science.gov (United States)

    Payne, P.

    1967-01-01

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

  19. Total reflection x-ray fluorescence (TXRF)

    International Nuclear Information System (INIS)

    Hockett, R.S.

    1995-01-01

    Total reflection X-Ray Fluorescence (TXRF) is a glancing x-ray analytical technique which is used primarily to measure surface metal contamination on semiconductor substrates. This is a review of Total reflection X-Ray Fluorescence (TXRF) applications for silicon semiconductor processing. In addition, some comments are made about the future of TXRF, and in particular, synchrotron radiation TXRF (SR-TXRF)

  20. Automatic weld joint X-ray inspection

    International Nuclear Information System (INIS)

    Richter, H.U.; Linke, D.; Siems, K.D.; Kruse, H.; Schuetze, E.

    1990-01-01

    A gantry mounted robotic x-ray inspection unit has been developed for the series testing of small and medium sized welded components (pipe bends and nozzles). The unit features computer controlled positioning of the x-ray tube and x-ray image amplifier. Image quality classes 2 and even 1 could be achieved without difficulty. (author)

  1. Miniature X-ray Tube for Electric Brachytherapy using Carbon Nanotube Field Emitter

    International Nuclear Information System (INIS)

    Heo, Sung Hwan; Kim, Hyun Jin; Ha, Jun Mok; Cho, Sung Oh

    2011-01-01

    An electric brachytherapy using a miniature x-ray tube has a major advantage to reduce the x-ray exposure of human body during the cancer radiation therapy by optimal positioning of x-ray radiation source and treatment objectives. In the view of a smaller electronic x-ray source, the CNT field emitter based xray tube can be more minimized than thermionic filament emitter based one because of a simple power supplier connection of cold field emission in diode type as well as a higher electron emission brightness of CNT. This abstract is for introducing the design of a prototype CNT field emitter based miniature x-ray tube. We have vacuum sealed CNT miniature x-ray tube with 7∼10 mm diameter, and characteristics of electron emission and x-ray transportation using MCNP5 code are surveyed

  2. Pulsating X-ray sources

    International Nuclear Information System (INIS)

    Trumper, J.

    1986-01-01

    The discovery of pulsating X-ray sources in close binary systems was one of the major achievements of the Uhuru satellite. Today one knows about two dozens of these sources with pulsational periods between 69 ms and 835 s. In most cases the X-ray source orbits an early-type star of high mass having a rather large optical luminosity. There are a few exceptions: GX1+4 is associated with a late-type (M6) giant, 4U1616-67 has a comparison of very low mass (≤ 0.1 M/sub sub solar/), and Her X-1 is a borderline case, since its counterpart HZ Her is an A-F star of -- 2/sub sub solar/. It is clear that the X-ray sources in these systems are rotating magnetized neutron stars accreting from their normal companion, probably in most cases via Roche lobe overflow which leads to the formation of an accretion disk. In some cases (e.g. Vela X-1) the accretion proceeds via a stellar wind. Pulsations occur because in the immediate vicinity of the neutron star the matter is funneled by the strong magnetic field onto the polar caps where a hot and very luminous plasma is formed. Typical luminosities are huge, namely of the order of 10/sup 37/ erg/s which are radiated at effective temperatures of -- 10/sup 8/ K. Much has been learned about these systems and about neutron stars from studies of pulse arrival times and source spectra. The author briefly summarizes some of the major results and discusses some very recent results obtained with EXOSAT

  3. Protonium X-ray spectroscopy

    CERN Document Server

    Gotta, D

    1999-01-01

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

  4. X-ray intensifying screens

    International Nuclear Information System (INIS)

    Bossomaier, T.R.J.; Sangway, P.C.

    1979-01-01

    It is claimed that stabilization of X-ray intensifying screens against discolouration and hydrolysis of lanthanum or gadolinium oxyhalide phosphors can be achieved by incorporating into the phosphor/binder formulation a compound containing free epoxy groups. Suitable epoxy compounds include gamma glycidoxy trimethoxy silane and dimethyl di(m-glycidoxy methylphenyl) methane. The oxyhalide may be activated by Tb, Tm or Yb and may be mixed with other phosphors. Plasticisers and organo-tin stabilisers for the formulation are given. Many binders are specified, preferably these should not react with the free epoxy groups. (UK)

  5. Errors in chest x-ray interpretation

    International Nuclear Information System (INIS)

    Woznitza, N.; Piper, K.

    2015-01-01

    Full text: Reporting of adult chest x-rays by appropriately trained radiographers is frequently used in the United Kingdom as one method to maintain a patient focused radiology service in times of increasing workload. With models of advanced practice being developed in Australia, New Zealand and Canada, the spotlight is on the evidence base which underpins radiographer reporting. It is essential that any radiographer who extends their scope of practice to incorporate definitive clinical reporting perform at a level comparable to a consultant radiologist. In any analysis of performance it is important to quantify levels of sensitivity and specificity and to evaluate areas of error and variation. A critical review of the errors made by reporting radiographers in the interpretation of adult chest x-rays will be performed, examining performance in structured clinical examinations, clinical audit and a diagnostic accuracy study from research undertaken by the authors, and including studies which have compared the performance of reporting radiographers and consultant radiologists. overall performance will be examined and common errors discussed using a case based approach. Methods of error reduction, including multidisciplinary team meetings and ongoing learning will be considered

  6. Method for spatially modulating X-ray pulses using MEMS-based X-ray optics

    Science.gov (United States)

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

    2015-03-10

    A method and apparatus are provided for spatially modulating X-rays or X-ray pulses using microelectromechanical systems (MEMS) based X-ray optics. A torsionally-oscillating MEMS micromirror and a method of leveraging the grazing-angle reflection property are provided to modulate X-ray pulses with a high-degree of controllability.

  7. Picosecond x-ray streak camera studies

    International Nuclear Information System (INIS)

    Kasyanov, Yu.S.; Malyutin, A.A.; Richardson, M.C.; Chevokin, V.K.

    1975-01-01

    Some initial results of direct measurement of picosecond x-ray emission from laser-produced plasmas are presented. A PIM-UMI 93 image converter tube, incorporating an x-ray sensitive photocathode, linear deflection, and three stages of image amplification was used to analyse the x-ray radiation emanating from plasmas produced from solid Ti targets by single high-intensity picosecond laser pulses. From such plasmas, the x-ray emission typically persisted for times of 60psec. However, it is shown that this detection system should be capable of resolving x-ray phenomena of much shorter duration. (author)

  8. Si(Li) X-ray detector

    International Nuclear Information System (INIS)

    Yuan Xianglin; Li Zhiyong; Hong Xiuse

    1990-08-01

    The fabrication technology of the 10∼80 mm 2 Si(Li) X-ray detectors are described and some problems concerning technology and measurement are discussed. The specifications of the detectors are shown as well. The Si(Li) X-ray detector is a kind of low energy X-ray detectors. Owing to very high energy resolution, fine linearity and high detection efficiency in the range of low energy X-rays, it is widely used in the fields of nuclear physics, medicine, geology and environmental protection, etc,. It is also a kernel component for the scanning electron microscope and X-ray fluorescence analysis systems

  9. NIKOLA TESLA AND THE X-RAY

    OpenAIRE

    Rade R. Babic

    2005-01-01

    After professor Wilhelm Konrad Röntgen published his study of an x-ray discovery (Academy Bulletin, Berlin, 08. 11. 1895.), Nikola Tesla published his first study of an x-ray on the 11th of March in 1896. (X-ray, Electrical Review). Until the 11th of August in 1897 he had published ten studies on this subject. All Tesla,s x-ray studies were experimental, which is specific to his work. Studying the nature of the x-ray, he established a new medical branch-radiology. He wrote:” There’s no doubt...

  10. Radiographic equipment for examining the absorption of X-rays or GAMMA-rays in a cross section of a body

    International Nuclear Information System (INIS)

    Hounsfield, G.N.

    1980-01-01

    The radiation leaving the body is stored in a large number of adjacent crystals. A time multiplex circuit ensures that the crystals are radiated by an infrared laser beam. They give out a light signal in turn corresponding to the absorbed radiation, which is accepted by a common photoelectric converter. (DG) [de

  11. The Effect of (99m)Tc on Dual-Energy X-Ray Absorptiometry Measurement of Body Composition and Bone Mineral Density

    DEFF Research Database (Denmark)

    Fosbøl, Marie Øbro; Dupont, Anders; Alslev, Louise

    2012-01-01

    the administration of a tracer marked with (99m)Tc were included. The patients underwent a whole-body DXA scan before and within 2h after tracer injection using a GE/Lunar Prodigy scanner. Control scans were performed on 40 volunteers, who had not received any radioactive tracer. In both phantom and patient...

  12. Comparison of Gross Body Fat-Water Magnetic Resonance Imaging at 3 Tesla to Dual Energy X-Ray Absorptiometry in Obese Women

    Science.gov (United States)

    Silver, HJ; Niswender, KD; Kullberg, J; Berglund, J; Johansson, L; Bruvold, M; Avison, MJ; Welch, EB.

    2012-01-01

    Improved understanding of how depot-specific adipose tissue mass predisposes to obesity-related comorbidities could yield new insights into the pathogenesis and treatment of obesity as well as metabolic benefits of weight loss. We hypothesized that three-dimensional contiguous “fat-water” MR imaging (FWMRI) covering the majority of a whole-body field of view (FOV) acquired at 3 Tesla (3T) and coupled with automated segmentation and quantification of amount, type and distribution of adipose and lean soft tissue would show great promise in body composition methodology. Precision of adipose and lean soft tissue measurements in body and trunk regions were assessed for 3T FWMRI and compared to DEXA. Anthropometric, FWMRI and DEXA measurements were obtained in twelve women with BMI 30–39.9 kg/m2. Test-retest results found coefficients of variation for FWMRI that were all under 3%: gross body adipose tissue (GBAT) 0.80%, total trunk adipose tissue (TTAT) 2.08%, visceral adipose tissue (VAT) 2.62%, subcutaneous adipose tissue (SAT) 2.11%, gross body lean soft tissue (GBLST) 0.60%, and total trunk lean soft tissue (TTLST) 2.43%. Concordance correlation coefficients between FWMRI and DEXA were 0.978, 0.802, 0.629, and 0.400 for GBAT, TTAT, GBLST and TTLST, respectively. While Bland Altman plots demonstrated agreement between FWMRI and DEXA for GBAT and TTAT, a negative bias existed for GBLST and TTLST measurements. Differences may be explained by the FWMRI FOV length and potential for DEXA to overestimate lean soft tissue. While more development is necessary, the described 3T FWMRI method combined with fully-automated segmentation is fast (<30 minutes total scan and post-processing time), noninvasive, repeatable and cost effective. PMID:23712980

  13. Cross-calibration of multi-frequency bioelectrical impedance analysis with eight-point tactile electrodes and dual-energy X-ray absorptiometry for assessment of body composition in healthy children aged 6-18 years.

    Science.gov (United States)

    Lim, Jung S; Hwang, Jin S; Lee, Jun A; Kim, Dong H; Park, Kyung D; Jeong, Jin S; Cheon, Gi J

    2009-04-01

    In diagnosis and treatment of obesity, body composition analysis including percent body fat (%BF) is useful in the clinical setting. Because bioelectrical impedance analysis (BIA) could be used quickly, easily and was non-invasive in clinical setting, the purpose of the present study was to evaluate the usefulness of multi-frequency BIA with eight-point tactile electrodes (MF-BIA8; InBody 720, Biospace) compared with dual-energy X-ray absorptiometry (DXA) in healthy children and adolescents. A total of 166 children and adolescents under 18 (male, n = 86; female, n = 80) were recruited. Height, weight, body mass index (BMI) and Tanner stage were measured for each subject. The body composition such as fat-free mass (FFM), fat mass (FM), and %BF was measured on BIA and DXA and compared. On linear regression analysis, DXA FFM = 1.006(BIA FFM) + 0.554, R(2) = 0.99 and the standard error of the estimate (SEE) was 1.16 kg; DXA FM = 0.971(BIA FM) - 0.596, R(2) = 0.93; SEE, 1.34 kg; and DXA %BF = 0.940(BIA %BF) - 1.026, R(2) = 0.858; SEE, 3.03%. Limit of agreement in FFM, FM, and %BF was 0.7 +/- 2.3 kg, -0.9 +/- 2.9 kg and -2.2 +/- 6.1%, respectively. Although the %BF was not interchangeable with DXA, MF-BIA8 (InBody 720; Biospace) could be used to measure body composition of children and adolescents in the clinical field because of its high precision.

  14. Miniature x-ray point source for alignment and calibration of x-ray optics

    International Nuclear Information System (INIS)

    Price, R.H.; Boyle, M.J.; Glaros, S.S.

    1977-01-01

    A miniature x-ray point source of high brightness similar to that of Rovinsky, et al. is described. One version of the x-ray source is used to align the x-ray optics on the Argus and Shiva laser systems. A second version is used to determine the spatial and spectral transmission functions of the x-ray optics. The spatial and spectral characteristics of the x-ray emission from the x-ray point source are described. The physical constraints including size, intensity and thermal limitations, and useful lifetime are discussed. The alignment and calibration techniques for various x-ray optics and detector combinations are described

  15. Multiple-energy X-ray subtraction imaging system

    International Nuclear Information System (INIS)

    Brody, WR.

    1982-01-01

    This invention relates to x-ray imaging systems, with particular reference to blood vessels. In a primary application the invention relates to obtaining isolated images of an administered contrast agent. The absorption of X-rays transmitted through a body is measured in a plurality of energy ranges and these measurements are processed to obtain image data with the soft tissue component eliminated. Such processed image data is obtained before and after the administration of a contrast agent, such as iodine, to the body. The two sets of processed image data are subtractively combined to obtain an isolated image of the contrast agent which is immune to motion of soft tissue. (author)

  16. Reduction of misclassification rates of obesity by body mass index using dual-energy X-ray absorptiometry scans to improve subsequent prediction of per cent fat mass in a Caucasian population

    DEFF Research Database (Denmark)

    Pedersen, Susie Dawn; Astrup, Arne; Skovgaard, Ib

    2011-01-01

    threshold could be calculated (BMIT), above which the patient would be obese by %FM criteria. Data were collected from individuals who had a DXA scan as part of a nutritional research study at the University of Copenhagen. BMI incorrectly classified 48/329 (14.6%) of men and 52/589 (8.8%) of women....... The majority of men with BMI 25–27 kg m-2 and women with BMI 24–26 kg m-2 were misclassified. Using multiple scan data (189 men, 311 women) and calculating the patient-specific constant C = (1 - %FM/100)3/2 ¥ BMI from baseline BMI and %FM, misclassification rates were halved for both genders when a personal......Recognition is increasing for the errors of body mass index (BMI) in classification of excess body fat. Dual-energy X-ray absorptiometry (DXA) is accurate to assess body fat mass per cent (%FM), but is underutilized clinically. We examined the prevalence of obesity misclassification by BMI...

  17. X-ray and gamma radiography devices

    International Nuclear Information System (INIS)

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

    2008-01-01

    When we are using this technique, we also must familiar with the device and instrument that used such as gamma projector, crawler, x-ray tubes and others. So this chapter discussed detailed on device used for radiography work. For the x-ray and gamma, their characteristics are same but the source to produce is a big different. X-ray produced from the machine meanwhile, gamma produce from the source such as Co-60 and IR-192. Both are electromagnetic waves. So, the reader can have some knowledge on what is x-ray tube, discrete x-ray and characteristic x-ray, how the machine works and how to control a machine, what is source for gamma emitter, how to handle the projector and lastly difference between x-ray and gamma. Of course this cannot be with the theory only, so detailed must be learned practically.

  18. X ray imaging microscope for cancer research

    Science.gov (United States)

    Hoover, Richard B.; Shealy, David L.; Brinkley, B. R.; Baker, Phillip C.; Barbee, Troy W., Jr.; Walker, Arthur B. C., Jr.

    1991-01-01

    The NASA technology employed during the Stanford MSFC LLNL Rocket X Ray Spectroheliograph flight established that doubly reflecting, normal incidence multilayer optics can be designed, fabricated, and used for high resolution x ray imaging of the Sun. Technology developed as part of the MSFC X Ray Microscope program, showed that high quality, high resolution multilayer x ray imaging microscopes are feasible. Using technology developed at Stanford University and at the DOE Lawrence Livermore National Laboratory (LLNL), Troy W. Barbee, Jr. has fabricated multilayer coatings with near theoretical reflectivities and perfect bandpass matching for a new rocket borne solar observatory, the Multi-Spectral Solar Telescope Array (MSSTA). Advanced Flow Polishing has provided multilayer mirror substrates with sub-angstrom (rms) smoothnesss for the astronomical x ray telescopes and x ray microscopes. The combination of these important technological advancements has paved the way for the development of a Water Window Imaging X Ray Microscope for cancer research.

  19. Submicron X-ray diffraction

    International Nuclear Information System (INIS)

    MacDowell, Alastair; Celestre, Richard; Tamura, Nobumichi; Spolenak, Ralph; Valek, Bryan; Brown, Walter; Bravman, John; Padmore, Howard; Batterman, Boris; Patel, Jamshed

    2000-01-01

    At the Advanced Light Source in Berkeley the authors have instrumented a beam line that is devoted exclusively to x-ray micro diffraction problems. By micro diffraction they mean those classes of problems in Physics and Materials Science that require x-ray beam sizes in the sub-micron range. The instrument is for instance, capable of probing a sub-micron size volume inside micron sized aluminum metal grains buried under a silicon dioxide insulating layer. The resulting Laue pattern is collected on a large area CCD detector and automatically indexed to yield the grain orientation and deviatoric (distortional) strain tensor of this sub-micron volume. A four-crystal monochromator is then inserted into the beam, which allows monochromatic light to illuminate the same part of the sample. Measurement of diffracted photon energy allows for the determination of d spacings. The combination of white and monochromatic beam measurements allow for the determination of the total strain/stress tensor (6 components) inside each sub-micron sized illuminated volume of the sample

  20. Assessment of EchoMRI-AH versus dual-energy X-ray absorptiometry by iDXA to measure human body composition.

    Science.gov (United States)

    Marlatt, K L; Greenway, F L; Ravussin, E

    2017-04-01

    Comparison of percent fat mass across different body composition analysis devices is important given variation in technology accuracy and precision, as well as the growing need for cross-validation of devices often applied across longitudinal studies. We compared EchoMRI-AH and Lunar iDXA quantification of percent body fat (PBF) in 84 adults (43M, 41F), with the mean age 39.7±15.9 years and body mass index (BMI) 26.2±5.3 kg/m 2 . PBF correlated strongly between devices (r>0.95, P<0.0001). A prediction equation was derived in half of the subjects, and the other half were used to cross-validate the proposed equation (EchoMRI-AH PBF=[(0.94 × iDXA PBF)+(0.14 × Age)+(3.3 × Female)-8.83). The mean PBF difference (predicted-measured) in the validation group was not different from 0 (diff=0.27%, 95% confidence interval: -0.42-0.96, P=0.430). Bland-Altman plots showed a bias with higher measured PBF on EchoMRI-AH versus iDXA in all 84 subjects (β=0.13, P<0.0001). The proposed prediction equation was valid in our cross-validation sample, and it has the potential to be applied across multicenter studies.

  1. Portable X-ray reflectometer using a low power polychromatic X-ray tube

    International Nuclear Information System (INIS)

    Ohnishi, Tsunemasa; Imashuku, Susumu; Yuge, Koretaka; Kawai, Jun; Shimura, Naomi

    2014-01-01

    We developed a portable X-ray reflectometer which measures energy dispersive X-ray reflectivity using a polychromatic X-rays from a low power (a few watts) X-ray tube and a silicon drift detector. A thin Cu film on silicon substrate using the portable reflectometer was measured. A fringe pattern was shifted due to the change of the X-ray incident angle. The measured peak position of the fringe pattern was satisfactorily agreed with the calculation. (author)

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

    OpenAIRE

    Sun, Tianxi; MacDonald, C. A.

    2013-01-01

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

  3. Dual energy X-ray absorptiometry body composition reference values of limbs and trunk from NHANES 1999-2004 with additional visualization methods.

    Directory of Open Access Journals (Sweden)

    Benjamin J Hinton

    Full Text Available Body Mass Index has traditionally been used as a measure of health, but Fat Mass Index (FMI and Lean Mass Index (LMI have been shown to be more predictive of mortality and health risk. Total body FMI and LMI reference curves have particularly been useful in quantifying sarcopenia and sarcopenic obesity. Research has shown regional composition has significant associations to health outcomes. We derived FMI and LMI reference curves of the regions of the body (leg, arm, and trunk for 15,908 individuals in the 1999-2004 National Health and Nutrition Examination Survey data for each sex and ethnicity using the Lambda-Mu-Sigma (LMS method and developed software to visualize this regional composition. These reference curves displayed differentiation between males and females during puberty and sharper limb LMI declines during late adulthood for males. For adults ages 30-50, females had 39%, 83%, and 47% larger arm, leg, and trunk FMI values than males, respectively. Males had 49%, 20%, and 15% higher regional LMI values than females for the arms, legs, and trunk respectively. The leg FMI and LMI of black females were 14% and 15% higher respectively than those of Hispanic and white females. White and Hispanic males had 37% higher trunk FMI values than black males. Hispanic females had 20% higher trunk FMI than white and black females. These data underscore the importance of accounting for sex and ethnicity in studies of regional composition. This study is the first to produce regional LMI and FMI reference tables and curves from the NHANES dataset. These reference curves provide a framework useful in studies and research involving sarcopenia, obesity, sarcopenic obesity, and other studies of compositional phenotypes. Further, the software tool we provide for visualizing regional composition will prove useful in monitoring progress in physical therapy, diets, or other attempts to attain healthier compositions.

  4. Development of Compton X-ray spectrometer for high energy resolution single-shot high-flux hard X-ray spectroscopy

    International Nuclear Information System (INIS)

    Kojima, Sadaoki; Ikenouchi, Takahito; Arikawa, Yasunobu; Sakata, Shohei; Zhang, Zhe; Abe, Yuki; Nakai, Mitsuo; Nishimura, Hiroaki; Shiraga, Hiroyuki; Fujioka, Shinsuke; Azechi, Hiroshi; Ozaki, Tetsuo; Miyamoto, Shuji; Yamaguchi, Masashi; Takemoto, Akinori

    2016-01-01

    Hard X-ray spectroscopy is an essential diagnostics used to understand physical processes that take place in high energy density plasmas produced by intense laser-plasma interactions. A bundle of hard X-ray detectors, of which the responses have different energy thresholds, is used as a conventional single-shot spectrometer for high-flux (>10 13 photons/shot) hard X-rays. However, high energy resolution (Δhv/hv < 0.1) is not achievable with a differential energy threshold (DET) X-ray spectrometer because its energy resolution is limited by energy differences between the response thresholds. Experimental demonstration of a Compton X-ray spectrometer has already been performed for obtaining higher energy resolution than that of DET spectrometers. In this paper, we describe design details of the Compton X-ray spectrometer, especially dependence of energy resolution and absolute response on photon-electron converter design and its background reduction scheme, and also its application to the laser-plasma interaction experiment. The developed spectrometer was used for spectroscopy of bremsstrahlung X-rays generated by intense laser-plasma interactions using a 200 μm thickness SiO 2 converter. The X-ray spectrum obtained with the Compton X-ray spectrometer is consistent with that obtained with a DET X-ray spectrometer, furthermore higher certainly of a spectral intensity is obtained with the Compton X-ray spectrometer than that with the DET X-ray spectrometer in the photon energy range above 5 MeV.

  5. Adjustment of a direct method for the determination of man body burden in Pu-239 on by X-ray detection of U-235

    International Nuclear Information System (INIS)

    Boulay, P.

    1968-04-01

    The use of Pu-239 on a larger scale sets a problem about the contamination measurement by aerosol at lung level. A method of direct measurement of Pu-239 lung burden is possible, thanks to the use of a large area window proportional counter. A counter of such pattern, has been especially carried out for this purpose. The adjustment of the apparatus allows an adequate sensibility to detect a contamination at the maximum permissible body burden level. Besides, a method for individual 'internal calibration', with a plutonium mock: the protactinium-233, is reported. (author) [fr

  6. Reproducibility and accuracy of body composition assessments in mice by dual energy x-ray absorptiometry and time domain nuclear magnetic resonance.

    Science.gov (United States)

    Halldorsdottir, Solveig; Carmody, Jill; Boozer, Carol N; Leduc, Charles A; Leibel, Rudolph L

    2009-01-01

    OBJECTIVE: To assess the accuracy and reproducibility of dual-energy absorptiometry (DXA; PIXImus(™)) and time domain nuclear magnetic resonance (TD-NMR; Bruker Optics) for the measurement of body composition of lean and obese mice. SUBJECTS AND MEASUREMENTS: Thirty lean and obese mice (body weight range 19-67 g) were studied. Coefficients of variation for repeated (x 4) DXA and NMR scans of mice were calculated to assess reproducibility. Accuracy was assessed by comparing DXA and NMR results of ten mice to chemical carcass analyses. Accuracy of the respective techniques was also assessed by comparing DXA and NMR results obtained with ground meat samples to chemical analyses. Repeated scans of 10-25 gram samples were performed to test the sensitivity of the DXA and NMR methods to variation in sample mass. RESULTS: In mice, DXA and NMR reproducibility measures were similar for fat tissue mass (FTM) (DXA coefficient of variation [CV]=2.3%; and NMR CV=2.8%) (P=0.47), while reproducibility of lean tissue mass (LTM) estimates were better for DXA (1.0%) than NMR (2.2%) (advantages compared to DXA, such as speed of measurement and the ability to scan unanesthetized animals.

  7. X-Ray Diffraction of Iron Containing Samples

    NARCIS (Netherlands)

    Mos, Yvonne M.; Vermeulen, Arnold C.; Buisman, Cees J.N.; Weijma, Jan

    2018-01-01

    In X-ray diffraction, a good combination of configuration and sample is essential. Copper radiation for iron containing materials leads to a high background. Although this has been recognized, many researchers still use this combination. To clearly show the unsuitability of copper radiation for iron

  8. Overview of surface/interface X-ray scattering

    International Nuclear Information System (INIS)

    Chen, Haydn H.D.; Aburano, R.D.

    1997-01-01

    The theory and nomenclature of 2-D diffraction experiments is described. Some topics deemed essential to understanding the experimental investigations were presented in detail, while others were explained qualitatively. A number of sources available for more detailed and quantitative explanations and examples of surface/interface X-ray scattering are given

  9. X-ray and neutron techniques for nanomaterials characterization

    CERN Document Server

    2016-01-01

    Fifth volume of a 40 volume series on nanoscience and nanotechnology, edited by the renowned scientist Challa S.S.R. Kumar. This handbook gives a comprehensive overview about X-ray and Neutron Techniques for Nanomaterials Characterization. Modern applications and state-of-the-art techniques are covered and make this volume an essential reading for research scientists in academia and industry.

  10. Estimates of body fat in children by Hologic QDR-2000 and QDR-4500A dual-energy X-ray absorptiometers compared with deuterium dilution.

    Science.gov (United States)

    Robotham, Delphine R; Schoeller, Dale A; Mercado, Arlene B; Mirch, Margaret C; Theim, Kelly R; Reynolds, James C; Yanovski, Jack A

    2006-03-01

    We evaluated the accuracy with which the Hologic QDR-4500A and QDR-2000 densitometers measure fat mass (FM) in 95 children. FM was derived from total body water measured by deuterium dilution (DD) in all children, by QDR-4500A in 50, and by QDR-2000 in 45 children. Compared with DD, both instruments underestimated FM (QDR-4500A: 3.35 +/- 2.5 kg, P < 0.0001; QDR-2000: 1.05 +/- 1.5 kg, P < 0.0001). Both absorptiometers showed magnitude biases relative to DD (QDR-4500: r = +0.70, P < 0.001; QDR-2000: r = -0.51, P < 0.001). We conclude that neither densitometer is equivalent to DD for estimation of children's FM. The QDR-4500A's current calibration seems to provide an even greater underestimate of FM than the QDR-2000.

  11. Ultrafast time-resolved X-ray diffraction using an optimized laser-plasma based X-ray source

    International Nuclear Information System (INIS)

    Lu, Wei

    2013-01-01

    Femtosecond X-ray pulses are invaluable tools to investigate the structural dynamics triggered by a femtosecond laser pulse. These ultrashort X-ray pulses can be provided by lab-sized laser-produced plasma X-ray sources. This thesis is dedicated to optimizing the X-ray emission from the X-ray source at the University of Duisburg-Essen and using this source to investigate ultrafast structural dynamics in laser excited materials. For these purposes, detailed investigations on how the laser intensities, target thicknesses, angles of incidence and different pre-pulse/pre-plasma conditions affecting the emission of Kα-photons from Cu and Ti targets were performed. The outcomes from these studies are applied to optimize the X-ray production of the existing X-ray source for time resolved X-ray diffraction (TRXD) experiments. In the mean time, in order to improve the measurement sensitivity/accuracy, and automatize and speed up the experimental procedures, several other improvements have been implemented in the experimental setup for TRXD experiments. These improvements of the setup are essential to achieve the results of the three TRXD experiments discussed in this thesis. In the first experiment, Debye-Waller effect in a thin laser-excited Au film was observed. The drop of measured diffraction signal with a decay time constant of 4.3±1 ps was measured for high excitation fluences. This result is in good agreement with previous experimental results as well as the Two-Temperature Model (TTM) calculations at high fluences. The second experiment extends the studies of coherent optical phonons in laser-excited Bi to a higher excitation fluence range that has not been investigated previously. Large amplitude coherent atomic motion and a complete softening of the A1g phonon mode were observed. These observations represents conclusive experimental evidence that the Peierls distortion, which defines the equilibrium structure of Bi, vanishes and the material is transformed into

  12. Study of bioaccumulation and biotransformation by microanalytical X-ray techniques: investigation of distribution and speciation of Cu and Cr in the body of the plant-feeding nematode, Xiphinema vuittenezi

    Science.gov (United States)

    Sávoly, Zoltán; Záray, Gyula

    2014-11-01

    Free-living nematodes, due to their microscopic size and quite complex life processes can be widely applied as biological model organisms to study the effect of soil pollutants. The modern X-ray spectrometric methods enable the individual analysis of microscopic biological samples, hereby expanding the scope of environmental and toxicological sciences. In order to study the uptake and bioaccumulation of Cu and Cr by nematodes (Xiphinema vuittenezi), the worms were starved in tap water for five days, and then treated with solutions of CuSO4, Cu(NO3)2, KCr(SO4)2 or K2CrO4 for 1-120 h. The effect of two soil-polluting elements, Cu, which is often applied in herbicides, and Cr, which is essential in the form of Cr(III), but toxic if it occurs as Cr(VI), on soil-inhabiting nematodes was studied. The uptake of these toxicants and their bioaccumulation was investigated by TXRF, following a two-step sample digestion method (digestion with HNO3 and using cold O plasma). Their effect on the essential element content of nematodes was also studied. Differences were found between the uptake of Cr(III) and Cr(VI). The Cr(III) causes decreased Zn content comparing with untreated nematodes, for Cr(VI) it was not observed. Elemental maps in the cross-sections of the worms prepared by focused gallium ion beam, following a special sample preparation method (quick-freezing in liquid nitrogen for 2 min and lyophilization for 72 h) were collected by scanning electron microscope equipped with energy dispersive X-ray detector. The distribution of Cr-P and Cu-P showed a similar pattern, however, the distribution of S deviated from these ones. According to these findings, the role of P-containing ligands in the binding of Cu and Cr is more characteristic than of S-containing ones. With the purpose of studying the speciation of the Cu and Cr in the worm, X-ray absorption near edge structure spectrometry was applied. The sample preparation method was the same as in the case of the elemental

  13. X-ray phase analysis of nickel superalloys

    International Nuclear Information System (INIS)

    Khayutin, S.G.

    2004-01-01

    An X-ray diffraction technique for determining phase composition is proposed for an intermetallic system of NiAl-Ni 3 Al and is based on the comparison of X-ray interference line intensity for two phases. Its application to heat resistant intermetallic coatings of nickel base alloys has restrictions associated with coatings nonhomogeneity in thickness. These restrictions are noted to be not essential if the reflecting layer thickness does not exceed the thickness of a chemically homogeneous layer in the coating [ru

  14. Verification of industrial x-ray machine: MINTs experience

    International Nuclear Information System (INIS)

    Aziz Amat; Saidi Rajab; Eesan Pasupathi; Saipo Bahari Abdul Ratan; Shaharudin Sayuti; Abd Nassir Ibrahim; Abd Razak Hamzah

    2005-01-01

    Radiation and electrical safety of the industrial x-ray equipment required to meet Atomic Energy Licensing Board(AELB) guidelines ( LEM/TEK/42 ) at the time of installation and subsequently a periodic verification should be ensured. The purpose of the guide is to explain the requirements employed in conducting the test on industrial x-ray apparatus and be certified in meeting with our local legislative and regulation. Verification is aimed to provide safety assurance information on electrical requirements and the minimum radiation exposure to the operator. This regulation is introduced on new models imported into the Malaysian market. Since June, 1997, Malaysian Institute for Nuclear Technology Research (MINT) has been approved by AELB to provide verification services to private company, government and corporate body throughout Malaysia. Early January 1997, AELB has made it mandatory that all x-ray equipment for industrial purpose (especially Industrial Radiography) must fulfill certain performance test based on the LEM/TEK/42 guidelines. MINT as the third party verification encourages user to improve maintenance of the equipment. MINT experiences in measuring the performance on intermittent and continuous duty rating single-phase industrial x-ray machine in the year 2004 indicated that all of irradiating apparatus tested pass the test and met the requirements of the guideline. From MINT record, 1997 to 2005 , three x-ray models did not meet the requirement and thus not allowed to be used unless the manufacturers willing to modify it to meet AELB requirement. This verification procedures on electrical and radiation safety on industrial x-ray has significantly improved the the maintenance cultures and safety awareness in the usage of x-ray apparatus in the industrial environment. (Author)

  15. The Mapping X-Ray Fluorescence Spectrometer (MAPX)

    Science.gov (United States)

    Blake, David; Sarrazin, Philippe; Bristow, Thomas; Downs, Robert; Gailhanou, Marc; Marchis, Franck; Ming, Douglas; Morris, Richard; Sole, Vincente Armando; Thompson, Kathleen; hide

    2016-01-01

    MapX will provide elemental imaging at =100 micron spatial resolution over 2.5 X 2.5 centimeter areas, yielding elemental chemistry at or below the scale length where many relict physical, chemical, and biological features can be imaged and interpreted in ancient rocks. MapX is a full-frame spectroscopic imager positioned on soil or regolith with touch sensors. During an analysis, an X-ray source (tube or radioisotope) bombards the sample surface with X-rays or alpha-particles / gamma rays, resulting in sample X-ray Fluorescence (XRF). Fluoresced X-rays pass through an X-ray lens (X-ray µ-Pore Optic, "MPO") that projects a spatially resolved image of the X-rays onto a CCD. The CCD is operated in single photon counting mode so that the positions and energies of individual photons are retained. In a single analysis, several thousand frames are stored and processed. A MapX experiment provides elemental maps having a spatial resolution of =100 micron and quantitative XRF spectra from Regions of Interest (ROI) 2 centimers = x = 100 micron. ROI are compared with known rock and mineral compositions to extrapolate the data to rock types and putative mineralogies. The MapX geometry is being refined with ray-tracing simulations and with synchrotron experiments at SLAC. Source requirements are being determined through Monte Carlo modeling and experiment using XMIMSIM [1], GEANT4 [2] and PyMca [3] and a dedicated XRF test fixture. A flow-down of requirements for both tube and radioisotope sources is being developed from these experiments. In addition to Mars lander and rover missions, MapX could be used for landed science on other airless bodies (Phobos/Deimos, Comet nucleus, asteroids, the Earth's moon, and the icy satellites of the outer planets, including Europa.

  16. Combining X-ray and neutron crystallography with spectroscopy.

    Science.gov (United States)

    Kwon, Hanna; Smith, Oliver; Raven, Emma Lloyd; Moody, Peter C E

    2017-02-01

    X-ray protein crystallography has, through the determination of the three-dimensional structures of enzymes and their complexes, been essential to the understanding of biological chemistry. However, as X-rays are scattered by electrons, the technique has difficulty locating the presence and position of H atoms (and cannot locate H + ions), knowledge of which is often crucially important for the understanding of enzyme mechanism. Furthermore, X-ray irradiation, through photoelectronic effects, will perturb the redox state in the crystal. By using single-crystal spectrophotometry, reactions taking place in the crystal can be monitored, either to trap intermediates or follow photoreduction during X-ray data collection. By using neutron crystallography, the positions of H atoms can be located, as it is the nuclei rather than the electrons that scatter neutrons, and the scattering length is not determined by the atomic number. Combining the two techniques allows much greater insight into both reaction mechanism and X-ray-induced photoreduction.

  17. Quality control of X-ray irradiator by biological markers

    International Nuclear Information System (INIS)

    Miura, Miwa; Lukmanul Hakkim, F.; Yoshida, Masahiro; Matsuda, Naoki; Morita, Naoko

    2011-01-01

    The exposure of animals or cultured cells to radiation is the essential and common step in experimental researches to elucidate biological effects of radiation. When an X-ray generator is used as a radiation source, physical parameters including dose, dose rate, and the energy spectrum of X-ray play crucial roles in biological outcome. Therefore, those parameters are the important points to be checked in quality control and to be carefully considered in advance to the irradiation to obtain the accurate and reproductive results. Here we measured radiation dose emitted from the X-ray irradiator for research purposes by using clonogenic survival of cultured mammalian cells as a biological marker in parallel with physical dosimetry. The results drawn from both methods exhibited good consistency in the dose distribution on the irradiation stage. Furthermore, the close relationship was observed between cell survival and the photon energy spectrum by using different filter components. These results suggest that biological dosimetry is applicable to quality control of X-ray irradiator in adjunct to physical dosimetry and that it possibly helps better understanding of the optimal irradiating condition by X-ray users in life-science field. (author)

  18. Anomalous X-Ray Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Wendin, G.

    1979-01-01

    The availability of tunable synchrotron radiation has made it possible systematically to perform x-ray diffraction studies in regions of anomalous scattering near absorption edges, e.g., in order to derive phase information for crystal structure determination. An overview is given of recent experimental and theoretical work and discussion of the properties of the anomalous atomic scattering factor, with emphasis on threshold resonances and damping effects. The results are applied to a discussion of the very strong anomalous dispersion recently observed near the L3 edge in a cesium complex. Also given is an overview of elements and levels where similar behavior can be expected. Finally, the influence of solid state and chemical effects on the absorption edge structure is discussed. 64 references.

  19. Anomalous x-ray scattering

    International Nuclear Information System (INIS)

    Wendin, G.

    1979-01-01

    The availability of tunable synchrotron radiation has made it possible systematically to perform x-ray diffraction studies in regions of anomalous scattering near absorption edges, e.g. in order to derive phase information for crystal structure determination. An overview is given of recent experimental and theoretical work and discuss the properties of the anomalous atomic scattering factor, with emphasis on threshold resonances and damping effects. The results are applied to a discussion of the very strong anomalous dispersion recently observed near the L 3 edge in a cesium complex. Also given is an overview of elements and levels where similar behavior can be expected. Finally, the influence of solid state and chemical effects on the absorption edge structure is discussed. 64 references

  20. Diffractive X-Ray Telescopes

    International Nuclear Information System (INIS)

    Skinner, G.K.; Skinner, G.K

    2010-01-01

    Diffractive X-ray telescopes using zone plates, phase Fresnel lenses, or related optical elements have the potential to provide astronomers with true imaging capability with resolution several orders of magnitude better than available in any other waveband. Lenses that would be relatively easy to fabricate could have an angular resolution of the order of micro arc seconds or even better, that would allow, for example, imaging of the distorted spacetime in the immediate vicinity of the supermassive black holes in the center of active galaxies What then is precluding their immediate adoption Extremely long focal lengths, very limited bandwidth, and difficulty stabilizing the image are the main problems. The history and status of the development of such lenses is reviewed here and the prospects for managing the challenges that they present are discussed atmospheric absorption