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Sample records for acute x-ray exposure

  1. Medical management of severe local radiation injury after acute X-ray exposure

    Medical management during acute period in a case of severe local radiation injury after acute X-ray exposure includes 3 stages. During the fist stage patient got conservative treatment according to the common pathogenetic mechanisms of LRI (dis aggregating therapy, stimulation of regeneration, dis intoxication therapy, antibiotic therapy, pain relief therapy, Local anti-burn therapy-specific non-adhesive bandage with antiseptic and anti-burn medicaments); estimation of severity, deepness and area of injury by clinical picture and dates of instrumental methods of examining; defining necessity and volume of surgical treatment; preparing arrangements for surgical treatment. This stage ends with forming of demarcation line of a very hard severity of a Local Radiation Injure. The second stage includes necrectomy of the area of a very hard severity with microsurgical plastic by re vascularized flap and auto dermoplastic. The third stage - adaptation of re vascularized flap and total epithelization of injured area. (author)

  2. Management of dental x-ray exposure

    The effects of dental x-ray exposure and how they might be minimized were reviewed. The frequency of dental x-ray exposures in Japan was presented for each year, sex, age group and site of x-ray photography separately. The doses of exposure at various parts of the body per x-ray examination were also presented, and the probabilities of genetic damage, and of development of leukemia or cancer were calculated. The allowable dose of exposure for radiation workers was discussed. It is important to take account of radiation quality, area of irradiation field, and posture of patients to minimize the radiation effect. The actual statistics on the x-ray exposure at the dentists, distribution of the dispersed radiation in the x-ray room, methods of protection against exposure, and plans and designs of the x-ray room were discussed. (Kaihara, S.)

  3. In vivo proliferation of bone marrow stem cells of mice after combined long-term exposure to gamma radiation and acute exposure to X rays

    The aim of this paper was to ascertain whether a long-term exposure to gamma radiation at low dose rates, comparable to the professional permissible dose, can modify the response of bone marrow stem cells to single acute irradiation. The study was carried out by the method of exogenous spleen colonization. Continuous exposure to Co60 gamma rays was applied at dose rates of 0,223 mGy x h-1 and 1,25 mGy x h-1. The duration of exposure was 30-105 days, accumulated doses within this time were 0.16-0,56 Gy respectively. After the exposure was completed the mice were subjected to acute X-rays irradiation at the doses of 0,5-4,0 Gy. It was found the bone marrow stem cells, capable to form clones in the spleens, respond to the dose effect as well as at very low its values. The effect estimated by changed responsiveness to acute irradiation depends to accumulated dose only. The higher is the accumulated dose during long-term irradiation the greater is diminishing of repopulating ability of bone marrow cells after following acute irradiation. 4 refs., 3 figs., 1 tab. (author)

  4. X-ray exposures to dental patients

    An elastic mask worn by patients and a skeleton encased in plastic were instrumented with LiF thermoluminescent dosimeters to determine radiation exposures delivered from full-face diagnostic dental X-rays. Measurements were made using various panoramic radiographical and periapical machines. Locations of interest included skin surface, eyes, upper and lower teeth and thyroid. Exposures in the 100 mR range were common and a maximum of over 6000 mR was measured in the teeth region during a full-face examination with a periapical unit. In general, exposures received from periapical equipment were several times those obtained from panoramic devices. (author)

  5. A paediatric X-ray exposure chart

    The aim of this review was to develop a radiographic optimisation strategy to make use of digital radiography (DR) and needle phosphor computerised radiography (CR) detectors, in order to lower radiation dose and improve image quality for paediatrics. This review was based on evidence-based practice, of which a component was a review of the relevant literature. The resulting exposure chart was developed with two distinct groups of exposure optimisation strategies – body exposures (for head, trunk, humerus, femur) and distal extremity exposures (elbow to finger, knee to toe). Exposure variables manipulated included kilovoltage peak (kVp), target detector exposure and milli-ampere-seconds (mAs), automatic exposure control (AEC), additional beam filtration, and use of antiscatter grid. Mean dose area product (DAP) reductions of up to 83% for anterior–posterior (AP)/posterior–anterior (PA) abdomen projections were recorded postoptimisation due to manipulation of multiple-exposure variables. For body exposures, the target EI and detector exposure, and thus the required mAs were typically 20% less postoptimisation. Image quality for some distal extremity exposures was improved by lowering kVp and increasing mAs around constant entrance skin dose. It is recommended that purchasing digital X-ray equipment with high detective quantum efficiency detectors, and then optimising the exposure chart for use with these detectors is of high importance for sites performing paediatric imaging. Multiple-exposure variables may need to be manipulated to achieve optimal outcomes

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

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

  7. Differences of X-ray exposure between X-ray diagnostics with a conventional X-ray screen-system and with an image-intensifier-television-unit

    During X-ray diagnostics of patients in the II. Medizinische Poliklinik the X-ray exposure was determined. It corresponded to the data described in literature. Two groups were compared: 518 patients examined with a conventional X-ray screen-system and 642 patients examined with an image-intensifier-television-system. The results demonstrated that with exception of thoracical X-ray examination the replacing of the old system by the television system brought a remarkable increase of the X-ray exposure. The doses depended of the patients constitution to a high degree. (orig.)

  8. X-ray diagnosis of acute gastritis

    Abnormal gastric wall configurations in 27 cases of cause-unknown acute gastritis were studied roentgenographically with reference to their causative origins. Studies were made on roentgenograms (abnormal gastric wall configurations), endoscopic findings and extension of lesions of the subjected cases. Gastric contour showed 'staying', 'thumbprinting', 'undulate configuration' and 'squarish undulation', while 'chimney-like' finding suggestive of poor gastric wall stretch was observed in the whole antral region as well. The widened angulus ventriculi and expanded pyloric ring (insufficient constriction) were also seen. In some cases the lesion extended over to the duodenum and, as in the cases of acute gastritis, duodenal wall 'staying', 'thumbprinting' and varied duodenal wall undulation were seen in addition to edema and morphological changes of the Kerkring's folds. The lesions in the studied patients mostly extended from an epicenter of the antrum upward to the gastric corpus and downward near to Vater's papilla in the descending part of the duodenum. The affected regions were clearly distinguishable. It has been known that above-described roentgenographical findings in our studied patients were similar in part to those known in experimental studies carried out on animals with ischemic digestive tract. This strongly suggests that some of our patients had developed the disease due to ischemic causes. There were some discrepancies between roentgenographical (abnormal gastric wall configuration) and endoscopic findings in some studied patients. It has been our belief that abnormal gastric wall configuration reflects lesions in the inner part of the wall and, accordingly, roentgenographical examinations, as well as endoscopy, should be performed for the purpose of making correct diagnosis. It is also to be emphasized that angiography should be carried out on patients with relapsing acute gastritis without any specific cause. (author)

  9. Digital radiography can reduce scoliosis x-ray exposure

    Digital radiology is a new computerized system of acquiring x-rays in a digital (electronic) format. It possesses a greatly expanded dose response curve that allows a very broad range of x-ray dose to produce a diagnostic image. Potential advantages include significantly reduced radiation exposure without loss of image quality, acquisition of images of constant density irrespective of under or over exposure, and reduced repeat rates for unsatisfactory films. The authors prospectively studied 30 adolescents with scoliosis who had both conventional (full dose) and digital (full, one-half, or one-third dose) x-rays. They found digital made AP and lateral image with all anatomic areas clearly depicted at full and one-half dose. Digital laterals were better at full dose and equal to conventional at one-half dose. Cobb angles were easily measured on all one-third dose AP and on 8 of 10 one-third dose digital laterals. Digital clearly depicted the Risser sign at one-half and one-third dose and the repeat rate was nil in this study, indicating digital compensates well for exposure errors. The study indicates that digital does allow radiation dose to be reduced by at least one-half in scoliosis patients and that it does have improved image quality with good contrast over a wide range of x-ray exposure

  10. Reduction of Unwarranted Patient Exposure in X-ray examinations

    F. Bouzarjomehri

    2003-01-01

    Background/Objective: Protecting patients from unwarranted radiation is a great safety concern to radiology practitioners, as medical X-rays are the largest source of public exposure to ionizing radiation. Materials and Methods: The entrance skin exposure (ESE) was measured by solid state dosimeter for five common types of radiography. Dosimetery for a human of average size was performed in the radiology centers. The results of first ESE measurements together with recommendations according to...

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

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

  12. Radiation exposure caused by medical measures: X-rays

    To estimate the genetic and somatic risks connected with the diagnostic application of X-rays the corresponding population doses must be known. When determining the population doses considerable inaccuracies must be tolerated. Unavoidable is the error resulting from the different doses in the risk organ observed during the same type of examination. The organ dose during an X-ray examination depends on various factors. These dependences are well known, due to systematic examinations in connection with the development of calculation methods. It is, however, only rarely possible to exactly determine all parameters, especially the geometrical ones, during an X-ray examination and to obtain a reliable calculation. Systematic examinations have shown ways to reduce organ doses thus contributing to a general reduction in the radiation exposure and the radiation risks of the population. The risk values given which result from the application of X-rays in diagnosing can only be used as rough ideas which are most probably at the upper limit. (orig./HP)

  13. Retrospective epidemiological study of the X-Ray exposure

    Ivanov, E. V.; Kalnitsky, S. A.; Shubic, V. M.

    2004-07-01

    There are a large amount of epidemiological studies nowadays in the world which are devoted to the analysis of the medical effects and the radiation risk. But a few of them deal with the analysis of the medical diagnostic radiation influence on health. It is appropriate, for the large compared contingent of the patients and the possibility of comparing them in several decades after the exposure are necessary for the evaluation of the influence of small doses on health. Meanwhile the X-ray exposure of the population is one of the most important types of radiation influence among all the kinds and sources of radiation. It is characterized by high dose rate and the possibility of multiple influence on a weakened and diseased organism. In connection with that, the eleven of the indices of population health was analyzed for the first time in Russia. The population was influenced by different levels of X-ray exposure 10-50 years ago. The research was carried out in the two groups of the Tumen (Siberia) regions. These regions are more or less equal in the climatic; ecologic, social-economic and demographic conditions. Nevertheless, they are different even only in the value of accumulated doses of X-ray exposure of the population (mostly in 50-70s) more than three times. Disease and mortality cancer of population of the last ten years in the regions were analyzed. The regions were selected taking into account the absence of the influence of other possible negative environmental factors. The data are found as the result of the dosimetric and epidemiological studies, and the processing of the archive statistic information. These researches demonstrated that on the whole there is the considerable statistically proved rise of disease cancer in the regions with high level of long term accumulated doses of X-ray exposure of population. Inter-district differences in disease and mortality cancer run up to three times among people aged 60 and older. There are no statistically

  14. Retrospective epidemiological study of the X-Ray exposure

    There are a large amount of epidemiological studies nowadays in the world which are devoted to the analysis of the medical effects and the radiation risk. But a few of them deal with the analysis of the medical diagnostic radiation influence on health. It is appropriate, for the large compared contingent of the patients and the possibility of comparing them in several decades after the exposure are necessary for the evaluation of the influence of small doses on health. Meanwhile the X-ray exposure of the population is one of the most important types of radiation influence among all the kinds and sources of radiation. It is characterized by high dose rate and the possibility of multiple influence on a weakened and diseased organism. In connection with that, the eleven of the indices of population health was analyzed for the first time in Russia. The population was influenced by different levels of X-ray exposure 10-50 years ago. The research was carried out in the two groups of the Tumen (Siberia) regions. These regions are more or less equal in the climatic; ecologic, social-economic and demographic conditions. Nevertheless, they are different even only in the value of accumulated doses of X-ray exposure of the population (mostly in 50-70s) more than three times. Disease and mortality cancer of population of the last ten years in the regions were analyzed. The regions were selected taking into account the absence of the influence of other possible negative environmental factors. The data are found as the result of the dosimetric and epidemiological studies, and the processing of the archive statistic information. These researches demonstrated that on the whole there is the considerable statistically proved rise of disease cancer in the regions with high level of long term accumulated doses of X-ray exposure of population. Inter-district differences in disease and mortality cancer run up to three times among people aged 60 and older. There are no statistically

  15. Radiation exposure in X-ray mammography - a review

    When discussing the radiation risk of X-ray mammography, the magnitude of the dose applied has decisive importance. The radiation exposure of the breast is the predominant factor in risk considerations, since it contributes more than 98% to the effective dose of this examination. At present, it is generally assumed that, with regard to cancer induction by ionizing radiation, the glandular tissue is the most vulnerable part in the breast. Therefore, the average glandular dose, i.e., the mean value of the absorbed dose in the glandular tissue, is used for a description of the radiation risk. The average glandular dose cannot be measured directly, but is calculated under certain assumptions from the experimentally determined entrance surface air kerma or entrance surface dose by the use of a so-called conversion factors. During the seventies, i.e., in the era of the industrial type X-ray film, the mean value of the average glandular dose per exposure for a larger sample of patients (n> 100) was about 20 mGy. Due to the progress in radiographic technique such as, for example, the use of sensitive filmscreen systems, optimized radiation qualities and modern automatic exposure control units this value has now decreased to about 1 mGy. Further dose reductions seem possible by the introduction of digital image receptors. (orig.)

  16. Reduction of Unwarranted Patient Exposure in X-ray examinations

    "F. Bouzarjomehri "

    2003-06-01

    Full Text Available Background/Objective: Protecting patients from unwarranted radiation is a great safety concern to radiology practitioners, as medical X-rays are the largest source of public exposure to ionizing radiation. Materials and Methods: The entrance skin exposure (ESE was measured by solid state dosimeter for five common types of radiography. Dosimetery for a human of average size was performed in the radiology centers. The results of first ESE measurements together with recommendations according to CRCPD and NRPB were returned to the radiology centers. Two months later, all ESE measurements were repeated. Results: The mean, maximum and 3rd quartile ESEs were significantly decreased compared with the first measurements. This quality control program managed to decrease the patient doses (ESEs of AP and lateral lumbar spine, AP cervical and lateral skull radiographs by about %10, 25%, 30% and 25% respectively. Conclusion: This survey indicates that in X-ray examinations of the lumbar, thoracic and cervical spine, skull and chest the patient dose can be significantly reduced without ruining the imaging quality.

  17. Radiation Exposure in X-Ray and CT Examinations

    ... A-Z Radiation Dose in X-Ray and CT Exams What are x-rays and what do ... natural background radiation for: ABDOMINAL REGION: Computed Tomography (CT)-Abdomen and Pelvis 10 mSv 3 years Computed ...

  18. Computer program for diagnostic X-ray exposure conversion

    Presented is a computer program designed to convert any given set of diagnostic X-ray exposure factors sequentially into another, yielding either an equivalent photographic density or one increased or decreased by a specifiable proportion. In addition to containing the wherewithal with which to manipulate a set of exposure factors, the facility to print hard (paper) copy is included enabling the results to be pasted into a notebook and used at any time. This program was originally written as an investigative exercise into examining the potential use of computers for practical radiographic purposes as conventionally encountered. At the same time, its possible use as an educational tool was borne in mind. To these ends, the current version of this program may be used as a means whereby exposure factors used in a diagnostic department may be altered to suit a particular requirement or may be used in the school as a mathematical model to describe the behaviour of exposure factors under manipulation without patient exposure. (author)

  19. Cytogenetic studies with laser or X-ray exposures

    Account is given of studies involving a total of 21 peripheral blood cultures given the following treatments: exposure to 20 0.13-joule pulses from an optic quantum generator (ruby), 9; exposure to 1000 R X-rays, 9; and unexposed controls, 3. Exposures were carried out on three cultures from each experimental series at each of three time intervals, namely 24 h, 48 h, and 72 h after initiation of cultures. On any day, 40 well-spread metaphases were examined. High quality metaphases were photographed and karyotyped in conformity to the Chicago Conference criteria. In the laser experiment, chromosome aberrations were observed in 65% of methaphases analyzed vs. 5.3% in controls. Anomalies encountered included aneuploidy, with hypoploid metaphases predominating, polyploidy (triploidy, tetraploidy, and partial endoreduplication), and structural alterations. The following structural chromosome rearrangements are found: acentric fragments, mostly pairs, occasionally single, including minute chromosomes; dicentric and tricentric chromosomes; interstitial deletions; and chromosome translocations. Most varied and abundant chromosome aberrations were seen in 72-h irradiated cultures. The data presented offer a new opportunity for assessing genetic lesions after laser exposure and may help to determine threshold doses. (author)

  20. X-ray diagnosis in acute and chronic sport injuries

    Stress X-ray and arthrography are of importance in the diagnosis of joint injuries. Stress X-rays are of great value to testify instability of acromioclavicular joint, metacarpophalangeal joint of the thumb, but also the knee and the ankle joint. With arthrography it is possible to show up a rupture of the rotator cuff of the shoulder and also a lesion of the triangular disc of the wrist. Indication, technique and the interpretation of the stress X-rays and the arthrogramms are discussed. (orig.)

  1. Results of the control of the exposure times of dental X-ray

    The X-ray gyroscope presented enables the dental radiological personnel to check simply the exposure time of the X-ray unit as to its accuracy. Any load half-wave interval is displayed by a density point on an ORWO XR 5 3/4 x 7 1/2 radiographic film by utilizing the regularity of the emission ratio of one-pulse X-ray generators. A density point corresponds to 0.02 seconds. This method has been used to check and evaluate timers of 10 different X-ray units. The 'Stomax 100' timers showed the least deviations to the exposure time required. (author)

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

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

  3. Breast neoplasms in women treated with x-rays for acute postpartum mastitis

    Breast cancer has been studied by mail survey up to 34 years in 571 of 606 women treated with x-rays for acute postpartum mastitis. The incidence of neoplasms was compared with that of three nonirradiated control groups--nonirradiated sisters of the treated women, women with acute postpartum mastitis not treated with X-rays, and their nonirradiated sisters. For the irradiated group, with a mean dose of 247 rads to both breasts, the overall relative risk of breast cancer was 2.2 for years 10 to 34 post irradiation and 3.6 for 20 to 34. The dose response for malignant and benign breast neoplasms was compatible with a linear fit. For comparable total doses, fractionation of exposure did not reduce carcinogenic action. Women over age 30 years at radiation treatment had as great an excess risk of breast cancer as did younger women. The overall excess risk of developing breast cancer was about 8 to 10 cases per million women per rad per year, an increase of about 0.5% per rad

  4. X-ray characteristics of heart failure in patients with acute myocardial infarction

    Results of chest biomedical radiography in 250 men aged 22-69 years who had acute myocardial infarction were evaluated. Data were compared with the results of ECG, echocardiography, Judkins coronarography, and left ventriculography. X-ray signs of pulmonary venous hypertension in acute myocardial infarction, even not followed by cardiomegalia suggest lower left ventricular myocardial contractility. In this connection, the significance of follow-up X-ray monitoring becomes higher. In 25% of the young patients (aged 22-40 years) with prior acute myocardial infarction, the dimensions of the heart may be in the normal ranges even in the presence of X-ray signs of venous congestion. If there are no signs of mitral regurgitation in patients with ischremic heart disease, the enlarged left atrium may be regarded as an indirect X-ray sign of reduced left ventricular contractility. Extent of necrosis in patients with myocardial infarction effects hemodynamic changes in lungs

  5. X-ray exposure in utero and school performance: a population-based study of X-ray pelvimetry

    Aim: To investigate the association between exposure to ionising radiation from pelvimetric examinations in utero and school performance. Material and methods: This was a population-based cohort study comprising 46,066 children born in the county of Östergötland, Sweden, from 1980 through 1990. Through record linkage between Swedish registers, children exposed in utero to X-ray pelvimetry examination were compared to other children born in the same county during the study period, as well as to their unexposed siblings. Outcome variable was primary school grades, expressed in centiles and calculated through linear regression. Results: In the univariate analysis, children exposed to X-ray pelvimetry in utero had higher school grades compared to unexposed children (point estimate 3 centiles, 95% confidence interval [CI]: 1.5 to 4.6). When sex, mother's education and income, birth order, and birth position were included in the analysis; however, the difference was reduced and the association was no longer statistically significant (PE 1.4, 95% CI: –0.1 to 2.8). Comparing exposed children with their siblings showed no statistical difference in univariate analysis or in multivariate analysis. Conclusion: No suggestion was found of a negative effect on school performance from in utero exposure of diagnostic X-ray pelvimetry. -- Highlights: •Pelvimetric examinations expose fetus to low levels of radiation. •No detectable effect on childrens final primary school grades from pelvimetric examinations. •Pelvimetric examinations is a safe procedure for the fetus regarding shool performance

  6. Exposure to diagnostic X-rays and other risk factors for leukemia

    The knowledge on the risk of leukemia after irradiation with small doses of X-rays cumulated during a long time is limited. Such an exposure is typical for persons occupationally exposed to radiation or patients receiving diagnostic X-ray irradiation. Several investigators have found a relationship between exposure to chemical compounds and risk of leukemia. Therefore, it seemed to be interesting to investigate the risk of leukemia when other possible risk factors like exposure to X-rays are taken into account. (author). 2 figs., 2 tabs

  7. X-ray characteristics of acute pneumonia and its outcomes in infants

    The results of an X-ray stUdy of 921 infants of the first 3 years of life with acute pneumonia (focal-669, focal-conflUent-197, destrUctive-55) were analyzed. In 188 patients with the lethal oUtcome the X-ray and pathomorphological data were compared. Repeated examination of 336 children was done 1-2 yrs. later. The specificities of an X-ray and morphological picture of focal, focal-confluent and destructive pnevmonia and outcomes in infants are presented

  8. Radiation exposure during chest X-ray examinations in a premature intensive care unit: phantom studies

    Duetting, T.; Foerste, B.; Darge, K.; Troeger, J. [Heidelberg Univ. (Germany). Dept. of Paediatric Radiology; Knoch, T. [Heidelberg Univ. (Germany). Central Radiation Protection

    1999-03-01

    Background. There are few reports on the radiation dose received by infants, their family and radiographers exposed to scatter radiation in a premature baby intensive care unit. Objective. To evaluate the degree of radiation exposure from diagnostic X-ray examinations with mobile X-ray machines in a premature intensive care unit. Materials and methods. The radiation exposure of an adjacent newborn, the radiographer and other persons in the room was simulated using phantoms during X-ray examination of the chest using vertical and horizontal beams. Results. Most of the measured doses were below the registration limit of the measuring apparatus and had to be extrapolated by multiple exposures. Without exception, the maximal doses were significantly lower than the permitted limit for persons not professionally exposed to X-rays. Conclusions. Recommendations to avoid unnecessary radiation exposure are given. (orig.) With 2 figs., 3 tabs., 10 refs.

  9. Radiation exposure during chest X-ray examinations in a premature intensive care unit: phantom studies

    Background. There are few reports on the radiation dose received by infants, their family and radiographers exposed to scatter radiation in a premature baby intensive care unit. Objective. To evaluate the degree of radiation exposure from diagnostic X-ray examinations with mobile X-ray machines in a premature intensive care unit. Materials and methods. The radiation exposure of an adjacent newborn, the radiographer and other persons in the room was simulated using phantoms during X-ray examination of the chest using vertical and horizontal beams. Results. Most of the measured doses were below the registration limit of the measuring apparatus and had to be extrapolated by multiple exposures. Without exception, the maximal doses were significantly lower than the permitted limit for persons not professionally exposed to X-rays. Conclusions. Recommendations to avoid unnecessary radiation exposure are given. (orig.)

  10. Design And Measurement Of Radiation Exposure Rates At An X-Ray Diagnostic Radiological Unit

    Every radiation employees suffers radiation exposure risk while doing his job. It is important therefore to investigate the occupational health and safety of radiation employees on its relationship with the design and measurement of radiation exposure rates at an X-ray diagnostic radiological unit in this work, a case study was held on the radiological unit at BP-4 Yogyakarta for patient diagnostics, This research armed to investigate the relationship between the design of radiological unit for X-ray diagnostics and the location of the X-ray machine, based on the distance variable and radiation exposure rate during patient diagnostics. This was performed using radiological unit design data for X-ray diagnostics and the measurement of radiation exposure rates throughout patient diagnostics. The design data can then be used for determining the requirement of primary and secondary shielding materials for radiological unit as well as a calculation basis of radiation exposure rates during patient diagnostics. From the result of the research, it can be concluded that from the occupational health and safety point of view, radiation exposure around the X-ray machines are fairly good, both for the shielding materials in each X-ray room and the radiation exposures received by the workers, because they are far beyond the maximum permittable average limit (16.67 m R/days). (author)

  11. Pregnancy x-rays and childhood cancers: effects of exposure age and radiation dose

    Using data from the Oxford Survey of Childhood Cancers this paper examines the effect of foetal age and number of films used on the subsequent risk of childhood cancer associated with prenatal x-rays. X-rays early in pregnancy were taken for different reasons and required more films when compared with those taken in late pregnancy. Therefore, Mantel-Haenszel techniques were used to estimate the independent effects of (a) exposure age and (b) number of films. Age at exposure had a clearly significant effect; x-rays taken in the first trimester of pregnancy were 2.69 times as effective as x-rays taken in the third trimester. First trimester exposures were often the result of maternal illnesses, so these maternal illnesses were then included among the controlling factors. When this was done the first trimester x-rays were 2.73 times as effective as later exposures. First trimester x-rays were most strongly associated with the cancers which were diagnosed between 4 and 5 years of age. Although the number of films had no detectable effect upon relative risk calculated over all ages, multiple exposures were demonstrably associated with early age at diagnosis. (author)

  12. Radiation exposure and image quality in x-Ray diagnostic radiology physical principles and clinical applications

    Aichinger, Horst; Joite-Barfuß, Sigrid; Säbel, Manfred

    2012-01-01

    The largest contribution to radiation exposure to the population as a whole arises from diagnostic X-rays. Protecting the patient from radiation is a major aim of modern health policy, and an understanding of the relationship between radiation dose and image quality is of pivotal importance in optimising medical diagnostic radiology. In this volume the data provided for exploring these concerns are partly based on X-ray spectra, measured on diagnostic X-ray tube assemblies, and are supplemented by the results of measurements on phantoms and simulation calculations.

  13. STOMATA ANATOMICAL CHANGES ON LEAVES OF LILY TRUMPET (LILIUM LONGIFLORUM) AFTER EXPOSURE TO X RAYS RADIATION

    Ni Kadek Dwipayani Lestari; Ida Ayu Astarini; I.G.M. Oka Nurjaya

    2012-01-01

    Lily (L. longiflorum) is one of 280 genus of liliaceae family. Variation on flower colour, growth habit, flowering period (shelf life) is very limited in Indonesia, so that plant breeding techniques are required to obtain a wide variety of plants. Physical mutation, radiation with X rays were employed in this study. The aim of this study is to find out the effect of X-ray exposure on lily’s leaves stomata anatomy. Lily seeds were grown in vitro and seedlings were exposed to X ray. This study ...

  14. STOMATA ANATOMICAL CHANGES ON LEAVES OF LILY TRUMPET (LILIUM LONGIFLORUM AFTER EXPOSURE TO X RAYS RADIATION

    Ni Kadek Dwipayani Lestari

    2012-03-01

    Full Text Available Lily (L. longiflorum is one of 280 genus of liliaceae family. Variation on flower colour, growth habit, flowering period (shelf life is very limited in Indonesia, so that plant breeding techniques are required to obtain a wide variety of plants. Physical mutation, radiation with X rays were employed in this study. The aim of this study is to find out the effect of X-ray exposure on lily’s leaves stomata anatomy. Lily seeds were grown in vitro and seedlings were exposed to X ray. This study employ CRD (completely randomized design with four dose exposure (0 krad, 5 krad, 7,5 krad dan 10 krad and 10 replicates each dose. Results show that to X ray causing reduction in stomata’s length, stomata amount, index, density of stomata that occurs randomly, compared to control.

  15. Child lead exposure determined from measurement of x-ray fluorescence of teeth in situ

    X-ray fluorescence from lead when irradiated by gamma rays from a Co-57 source was utilized to measure the lead concentration in children's teeth in situ. The sensitivity of the method was adequate to detect 15 ppM from a gamma ray exposure to the tooth approximately 1/10 the exposure of a routine dental x-ray examination. The tooth lead levels assayed using x-ray fluorescence correlated well with chemical assay techniques for both extracted permanent and shed primary teeth. Thirty children from the Children's Hospital of Philadelphia suspected of having elevated lead levels had tooth lead levels measured in situ determined using the x-ray fluorescent technique. The tooth lead concentration varied from a low of 16 ppM to a high of 56 ppM

  16. High precision instrumentation for measuring the true exposure time in diagnostic X-ray examinations

    One of the most important physical quantities to be evaluated in diagnostic radiology is the radiation exposure time experimented by the patient during the X-ray examination. IAEA and WHO organizations have suggested that any country must create a quality surveillance program to verify if each type of ionizing radiation equipment used in the hospitals and medical clinics are in conformity with the accepted uncertainties following the international standards. The purpose of this work is to present a new high precision methodology for measuring true exposure time in diagnostic X-ray examinations: pulsed, continuous or digital one. An electronic system named CronoX, which will be soon registered at the Brazilian Patent Office (INPI), is the equipment that provides such a high precision measurement. The principle of measurement is based on the electrical signal captured by a sensor that enters in a regeneration amplifier to transform it in a digital signal, which is treated by a microprocessor (uP). The signal treatment results in a two measured times: 1) Trx, the true X-ray exposure time; 2) Tnx, the time in which the X-ray machine is repeatedly cut off during the pulsed irradiation and there is no delivery dose to the patient. Conventional Polymat X-ray equipment and dental X-ray machines were used to generate X-ray photons and take the measurements with the electronic systems. The results show that such a high precision instrumentation displays the true exposure time in diagnostic X-ray examinations and indicates a new method to be purposed for the quality surveillance programs in radiology. (author)

  17. High precision instrumentation for measuring the true exposure time in diagnostic X-ray examinations

    Silva, Danubia B.; Santos, Marcus A.P.; Barros, Fabio R.; Santos, Luiz A.P., E-mail: danubia@hotmail.com, E-mail: lasantos@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2013-07-01

    One of the most important physical quantities to be evaluated in diagnostic radiology is the radiation exposure time experimented by the patient during the X-ray examination. IAEA and WHO organizations have suggested that any country must create a quality surveillance program to verify if each type of ionizing radiation equipment used in the hospitals and medical clinics are in conformity with the accepted uncertainties following the international standards. The purpose of this work is to present a new high precision methodology for measuring true exposure time in diagnostic X-ray examinations: pulsed, continuous or digital one. An electronic system named CronoX, which will be soon registered at the Brazilian Patent Office (INPI), is the equipment that provides such a high precision measurement. The principle of measurement is based on the electrical signal captured by a sensor that enters in a regeneration amplifier to transform it in a digital signal, which is treated by a microprocessor (uP). The signal treatment results in a two measured times: 1) T{sub rx}, the true X-ray exposure time; 2) T{sub nx}, the time in which the X-ray machine is repeatedly cut off during the pulsed irradiation and there is no delivery dose to the patient. Conventional Polymat X-ray equipment and dental X-ray machines were used to generate X-ray photons and take the measurements with the electronic systems. The results show that such a high precision instrumentation displays the true exposure time in diagnostic X-ray examinations and indicates a new method to be purposed for the quality surveillance programs in radiology. (author)

  18. Medical x-ray exposure doses as contaminants of atomic bomb doses.

    Yamamoto, O; Antoku, S; Russell, W J; Fujita, S; Sawada, S

    1988-03-01

    Since 1967 at the times of their biennial ABCC/RERF radiological examinations, all Adult Health Study (AHS) subjects have been interviewed to determine the exposures to medical x-rays they experienced in institutions other than RERF in order to estimate the numbers of examinations and corresponding doses which they received. These data have been stored on computer tapes together with the doses these subjects received during their radiological examinations in the ABCC/RERF Department of Radiology. Thus, their medical x-ray doses are available along with their atomic bomb doses (tentative 1965 doses revised, T65DR) for assessment of the role of ionizing radiation in the development of diseases. The medical x-ray doses incurred at RERF were assessed by means of phantom dosimetry. Those at other institutions were determined using phantom dosimetry data and results of surveys for trends in radiological examinations in Hiroshima and Nagasaki. By the end of 1982, the average medical x-ray doses to the active bone marrow were 12.04 mGy for A-bomb exposed groups and 8.92 mGy for control groups (not-in-cities); to the male gonads, 2.26 mGy and 1.89 mGy, respectively; and to the female gonads, 17.45 mGy and 12.58 mGy, respectively. Results for Hiroshima and Nagasaki were similar. The main impact of medical x-ray doses was in the lowest T65DR group. Medical x-ray active bone marrow doses ranged from 0.05-500% (mean, 35%) of A-bomb doses in the 10-99 mGy T65DR group. In the 100-999 mGy T65DR group, medical x-ray active bone marrow doses ranged from 0.005-50% (mean, 5%) of their T65DR. In the greater than 1,000-mGy T65DR group, medical x-ray exposures were proportionally less. Female active bone marrow and gonad doses were similar in magnitude to the male active bone marrow doses. Medical x-ray exposures produced smaller doses to the gonads of males than to those of the females. The use of medical x-rays is steadily increasing. Careful consideration of doses from medical sources

  19. Patient dose evaluations from medical X-ray exposure in Italy: an analysis of next data

    NEXT (Nationwide Evaluation of X-ray Trends) is a program for the evaluation of patient exposure in X-ray diagnostic tests. The program is aimed at reducing patient exposure by pin-pointing poor radiological techniques and improving them. CNEN (Comitato Nazionale per l'Energia Nucleare) and ISS (Istituto Superiore di Sanita) have been developing such a program in Italy since 1976. Up to now two regional administrations applied the method and regional operators collected the needed data in all the medical institutions in their areas. The results show a wide spread of values for all the parameters studied in the 12 X-ray projections selected. Gonad dose and skin entrance exposure were found to be spread over a range up to about two orders of magnitude. (H.K.)

  20. The primary exposure standard of ENEA for medium energy X-ray: characteristics and measurements procedures

    A description is given of a medium energy X-ray free-air chamber used, as primary exposure standard, at the Laboratorio di Metrologia delle Radiazioni Ionizzanti of the Enea in Italy. The main features of an X-ray facility for the production of radiation between 40 KeV and 400 KeV are also described. The measurements procedures are then analyzed with respect to the realization of the exposure unit in the relevant energy range. Finally the results of some international comparisons are reported

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

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

  2. Influence of chronic x-ray exposure on adrenal glucocorticoid function and adrenocorticocyte membrane potential

    The peculiarities of adrenal glucocorticoid function and membrane potential (MP) of zona fasciculata adrenocorticocyte (ACC) in rats after chronic x-ray exposure was studied. The changes of adrenal glucocorticoid function caused by chronic x-ray exposure within a relatively small period of irradiation (1.5 months) are obscure and manifest themselves only at physiological load. With the prolongation of the period (8 and 15 months), more considerable inhibition of the adrenal glucocorticoid function and disturbances in the membrane mechanisms of ACC MP level regulation are revealed

  3. Cost Benefit Optimization of the Israeli Medical Diagnostic X-Ray Exposure

    Diagnostic and therapeutic radiology is playing a major role in modern medicine. A preliminary survey was carried out during 1997 on 3 major Israeli hospitals in order to assess the extent of exposure of the population to medical x-rays (1). The survey has found that the annual collective dose of the Israeli population to x-ray medical imaging procedures (excluding radio-therapy) is about 7,500 Man-Sv. The results of the survey were analyzed in order to. 1. Carry out a cost-benefit optimization procedure related to the means that should be used to reduce the exposure of the Israeli patients under x-ray procedures. 2. Establish a set of practical recommendations to reduce the x-ray radiation exposure of patients and to increase the image quality. . Establish a number of basic rules to be utilized by health policy makers in Israel. Based on the ICRP-60 linear model risk assessments (2), the extent of the annual risk arising A.om the 7,500 Man-Sv medical x-ray collective dose in Israel has been found to be the potential addition of 567 cancer cases per year, 244 of which to be fatal, and a potential additional birth of 3-4 children with severe genetic damage per year. This assessment take into account the differential risk and the collective dose according to the age distribution in the Israeli exposed population, and excludes patients with chronic diseases

  4. A hard x-ray prototype production exposure station at NSLS

    Exposures conducted at the NSLS R and D beamline (X-27B) for High Aspect Ratio Precision Manufacture have proven sufficiently successful that the authors are constructing a dedicated hard x-ray exposure beamline. The new beamline (X-14B) provides an exposure field ∼ 120 mm wide, three times larger than that of X-27B. The scanner is based on the hydraulic system from the X-27B program. It is optimized for planar exposures and takes advantage of the full 525 mm stroke available. Exposures of multiple substrates and masks will be possible, with the fixturing supporting mounting of substrate holders from other groups (ALS, APS, CAMD, and UW). The function of this beamline is to establish a hard x-ray exposure station where manufacturing scale protocols can be developed and ultimately exploited for production runs

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

    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. Radiation exposure of children and young adults during X-ray investigations - experience and conclusions

    After discussing the existing regulations for radiation protection of patients in the field of pediatric X-ray diagnostics in the GDR the use of the effective dose equivalent HE and the medium dose equivalent HM for the determination of radiation exposure to children is shortly discussed. Using computer tomography images to determine the position and size of organs of children, and the data from measured depth dose distributions, the exposure related to the entrance dose caused by frequent X-ray examinations was calculated. Measurements of entrance doses at 3 pediatric hospitals for all examination types and the determination of the frequency of X-ray radiographies at 10 hospitals and 10 smaller diagnostic departments were used to calculate the per caput and the collective dose equivalents in the different age groups. Altogether the per caput dose equivalent of the children amounts to approximately 30% of the corresponding value for adults. As a conclusion, the following measures for the further reduction of radiation exposure are proposed: (1) technical measures like fixation of patients, shielding of organs, quality assurance, (2) elaboration of legal regulations, e.g. of a decree on the performance of pediatric X-ray examinations, and (3) training and continued education. Only by these means an appropriate indication (justification) and an efficient reduction of radiation exposure (optimization) can be achieved. (author)

  7. Radiation exposure in a modern, circularly scanned-beam laminographic X-ray inspection system.

    Fazzio, R S

    1998-01-01

    Circularly scanned-beam laminography is currently the predominant technique used for the nondestructive examination of printed circuit solder assemblies via cross-sectional X-ray imaging. Given industry trends towards double-sided assemblies and limited access components, cross-sectional X-ray inspection is furthermore becoming increasingly important. Use of X-rays for inspection of solder joints on loaded printed circuit boards nonetheless often leads to concern surrounding possible undesirable radiation effects on the circuitry mounted on the board. In this paper we develop a simple analytical model useful for predicting the radiation exposure rates in a scanned-beam laminography system. We demonstrate the validity of the model through a series of dosimetry experiments. PMID:22388470

  8. Evaluation of the medical exposure doses regarding dental examinations with different X-ray instruments

    Liu, Yi-Chi; Chuang, Keh-Shih; Yu, Cheng-Ching; Chao, Jiunn-Hsing; Hsu, Fang-Yuh

    2015-11-01

    Modern dental X-ray examination that consists of traditional form, panorama, and cone-beamed 3D technologies is one of the most frequent diagnostic applications nowadays. This study used the Rando Phantom and thermoluminescence dosimeters (TLD) to measure the absorbed doses of radiosensitive organs recommended by International Commission on Radiological Protection (ICRP), and whole body effective doses which were delivered due to dental X-ray examination performed with different types of X-ray instrument. Besides, enamel samples which performed reading with Electronic Paramagnetic Resonance (EPR) procedure were also used to estimate the tooth doses. EPR is a dose reconstruction method of measuring free radicals induced by radiation exposure to the calcified tissue (mainly in the tooth enamel or bone) to evaluate the accepted high dose. The tooth doses estimated by TLD and EPR methods were compared. Relationships between the tooth doses and effective doses by dental X-ray examinations with different types of X-ray equipment were investigated in this work.

  9. Observation of X-ray occupational exposure on psychological function of medical workers

    The present research is an attempt to study the psychological effects of long-term exposure to low-level X-ray on man. The subjects included 50 exposed people and 50 control. The battery of psychological tests consists of 10 subtests mainly involving memory and coordination ability. The results indicate that there are no statistical differences in all subtests between exposure and control group, but exposure group appears to be a little lower on most subtests about memory. With age, decline of psychological function is observed in all subtests in both groups. The subjects are further divided into three subgroups according to the number of X-ray exposed years. No statistical differences are found in all subgroups between exposure and control. Factor analysis has been made and two factors are obtained. factor 1 is mainly about speed of coordination, factor 2 is mainly about memory and attention. No statistical differences in factor scores are observed in all subgroups between exposure and control. Yet decline is found in factor 1 and factor 2 in both exposure and control groups with age. The results show that there is no significant effect of current dose level of X-ray exposure on human psychological function

  10. Beam quality independent attenuation phantom for estimating patient exposure from x-ray automatic exposure controlled chest examinations

    The periodic assessment of exposures in diagnostic radiology is an important part of a comprehensive quality assurance program. The most frequent radiologic examination conducted in the United States is chest radiography. Automatic exposure controlled (AEC) techniques are often used for this exam, and a standard patient-equivalent chest phantom is useful when estimating patient exposures on such systems. This is of particular importance if exposures are to be compared among AEC systems with different entrance x-ray spectra. Such a phantom has been developed to facilitate surveys of the average patient exposure from AEC posteroanterior chest radiography. The phantom is relatively lightweight and easily transportable, sturdy and made of readily available and relatively inexpensive materials (Lucite and aluminum). It accurately simulates the primary and scatter transmission through the lung-field regions of a patient-equivalent anthropomorphic phantom for x-ray spectra typically used in chest radiography. A clinical evaluation has been conducted to verify the patient equivalence of the phantom. Measurements of patient entrance skin exposure were obtained for a large number of patients on a variety of x-ray systems operated in the AEC mode using one or both lung-field detectors. Comparison of these data with exposure estimates derived from the phantom indicate that the phantom attenuates the x-ray beam in such a way that it can be employed to accurately and consistently estimate the mean exposure of the average patient under a variety of radiographic conditions

  11. The X-ray analysis of pulmonary manifestations in acute aspiration of trichlorethane

    Objective: To discuss the X-ray pulmonary changes in patients with acute aspiration of trichlorethane. Methods: Among 48 cases with acute aspiration of trichlorethane, 7 were male and 41 female, with ages ranged from 5.5 to 50 years old, mean age was 13.5 years old. 4 patients were diagnosed as mild acute intoxication, 22 as aspirating reaction, and 22 as uncomfortable reaction. And chest radiography was performed in all the cases. Results Pneumonia and bronchopneumonia was found in 4 cases with acute intoxication, inflammation around bronchial branches in 22 cases with aspirating reaction. The other cases were negative findings. Conclusions: Acute aspiration of trichlorethane may cause pneumonia, bronchopneumonia and inflammation around bronchial branches, which can be detected by chest radiography. (authors)

  12. Radiation exposure to chest X-rays in the neonatal nursery

    To measure how much very low birth-weight infants are exposed to chest X-rays during nursery, skin doses were calculated using phantoms under the same condition as that used in chest X-rays. Skin doses obtained were multiplied by the number of X-rays performed in 86 very low birth-weight infants (mean birth weight+-SD, 1163.0+-232.8 g; mean gestational age+-SD, 29.3+-3.0 week). Exposure doses per film ranged from 4.9 to 14.4 mR, with a mean dose of 6.1+-2.0 mR. Exposure doses per neonate ranged from 6.3 to 794.3 mR, with a mean dose of 170.4+-151.5 mR. The number of films per neonate ranged from one to 107, with a mean of 28.0+-24.9. Eighty-seven percent of X-rays were performed when the body weight was 1,500 g or less. Fourteen patients received 300 mR or more that may be the potential dose of radiation effects. (Namekawa, K)

  13. Radiation exposure in X-ray-based imaging techniques used in osteoporosis

    Recent advances in medical X-ray imaging have enabled the development of new techniques capable of assessing not only bone quantity but also structure. This article provides (a) a brief review of the current X-ray methods used for quantitative assessment of the skeleton, (b) data on the levels of radiation exposure associated with these methods and (c) information about radiation safety issues. Radiation doses associated with dual-energy X-ray absorptiometry are very low. However, as with any X-ray imaging technique, each particular examination must always be clinically justified. When an examination is justified, the emphasis must be on dose optimisation of imaging protocols. Dose optimisation is more important for paediatric examinations because children are more vulnerable to radiation than adults. Methods based on multi-detector CT (MDCT) are associated with higher radiation doses. New 3D volumetric hip and spine quantitative computed tomography (QCT) techniques and high-resolution MDCT for evaluation of bone structure deliver doses to patients from 1 to 3 mSv. Low-dose protocols are needed to reduce radiation exposure from these methods and minimise associated health risks. (orig.)

  14. Update of diagnostic medical and dental x-ray exposures in Romania

    This national study, the third in the last 15 years, updates the magnitude of medical radiation exposure from conventional x-ray examinations, in order to optimise the radiological protection to the population in a cost-effective manner. Effective doses from diagnostic radiology were estimated for adult and paediatric patients undergoing the 20 most important types of x-ray examination. Data were collected from 179 x-ray departments, selected by their annual workload, throughout the country. Estimates were made using two dosimetric quantities: entrance surface dose, derived from the absorbed dose in air measured by simulation of radiographic examinations, and dose-area product, measured during fluoroscopic examinations performed on adult and paediatric patients. Conversion coefficients to effective dose of the UK National Radiological Protection Board (NRPB) have been used in all calculations. The effective dose per patient from all medical x-ray examinations was 0.74 mSv and the resulting annual collective effective dose was 6930 man Sv, with annual effective dose per caput of 0.33 mSv. The current size of population exposure from diagnostic radiology is lower than the previous one by 40%, but could be about 30% higher by taking into account the estimated contribution from computed tomography (CT) procedures.

  15. Update of diagnostic medical and dental x-ray exposures in Romania

    Sorop, Ioana; Mossang, Daniela; Dadulescu, Elena [Radiation Hygiene Laboratory of Public Health Authority Dolj, 2, Constantin Lecca Street, Craiova (Romania); Iacob, Mihai Radu [University ' Alexandru Ioan Cuza' , 11, Carol I Street, 700506, Iasi (Romania); Iacob, Olga [Institute of Public Health, 14, Victor Babes Street, 700465 Iasi (Romania)], E-mail: danamossang@sanpubdj.ro

    2008-12-15

    This national study, the third in the last 15 years, updates the magnitude of medical radiation exposure from conventional x-ray examinations, in order to optimise the radiological protection to the population in a cost-effective manner. Effective doses from diagnostic radiology were estimated for adult and paediatric patients undergoing the 20 most important types of x-ray examination. Data were collected from 179 x-ray departments, selected by their annual workload, throughout the country. Estimates were made using two dosimetric quantities: entrance surface dose, derived from the absorbed dose in air measured by simulation of radiographic examinations, and dose-area product, measured during fluoroscopic examinations performed on adult and paediatric patients. Conversion coefficients to effective dose of the UK National Radiological Protection Board (NRPB) have been used in all calculations. The effective dose per patient from all medical x-ray examinations was 0.74 mSv and the resulting annual collective effective dose was 6930 man Sv, with annual effective dose per caput of 0.33 mSv. The current size of population exposure from diagnostic radiology is lower than the previous one by 40%, but could be about 30% higher by taking into account the estimated contribution from computed tomography (CT) procedures.

  16. Dual energy X-ray absorptiometry (DXA): can it detect acute scaphoid fractures?

    Stephen, A B; Pye, D; Lyons, A R; Oni, J A; Davis, T R C

    2005-02-01

    This prospective study investigated whether dual energy X-ray absorptiometry (DXA) could detect acute scaphoid fractures. We blindly compared 10 normal and 10 fractured scaphoid images produced with a new technique of DXA scan analysis. This measured and plotted the density of the scaphoid throughout its length, producing a linear graph of the scaphoids' density instead of a single area (g/cm2) measurement of bone density. These new plots only detected six of the 10 fractures and suggested that four of the normal controls were fractured. Thus, this technique of DXA scan analysis is neither sensitive nor specific for the detection of acute scaphoid fractures. PMID:15620498

  17. Medical radiation exposures from diagnostic x-ray procedures in India

    Medical exposures primarily refer to exposures to individuals as part of their own diagnosis or treatment. Diagnostic radiology continues to be the largest contributor to the effective dose to the population from all man-made sources of radiation. It is estimated that in India there are, on an average 105 x-ray examinations per 1000 persons per year, and that the annual per caput effective dose from medical exposures is 0.02 mSv. On the basis of consideration of benefit versus risk, the International Commission on Radiological Protection (ICRP) does not specify dose limits for medical exposure. The International Atomic Energy Agency stipulates that guidance levels for doses for each radiological procedure must be established. From a review of the doses to patients in diagnostic radiology reported by the United Nations Scientific Committee on the Effects of Atomic Radiation, it is observed that medical x-ray exposure is quite low in India. This could be attributed to the low frequency of x-ray examinations in the country and partly to good quality equipment, safe work practices and the type and frequency of a particular type of examination. (author). 10 refs., 2 figs., 4 tabs

  18. Mutation induction in human cells after low dose X ray exposure

    Mutations induced after low dose ionising radiation exposure have been intensively analysed not only for radiation risk estimation but also for basic understanding of cellular responses. Human lymphoblastoid TK6-20C cells were irradiated with 100 mGy of X rays and mutation at the heterozygous thymidine kinase (TK) locus was selected by trifluorothymidine resistance. Although the mutation frequency at the TK locus increased from 5.6x10-6 to 7.4x10-6, this increase was not statistically significant. However, molecular analysis of TK mutants exhibiting loss of heterozygocity (LOH) demonstrated a clear effect of such low dose IR exposure. Exposure to 100 mGy X ray increased the fraction of hemizygous-LOH from 10% to 42%. In previous experiments, a similar tendency in the increase of hemizygous-LOH was also observed in TK6 cells after exposure to a 2 Gy dose of X rays. This type of LOH can be considered as a result of end-joining repair of DNA double strand breaks. (author)

  19. Over-exposure from working with an X-ray crystallography set

    A service engineer was engaged in setting up and aligning a goniometer for use with a new X-ray generator and tube stand in the physics department of a university. The goniometer was of an old type, not matching with the shutter system of the tube shield. A piece of brass tubing 4cm in length was being used as a temporary enclosure for the useful X-ray beam, but the engineer realised after about four hours operation that the useful beam was not totally enclosed. A film badge worn by the engineer at waist level recorded a dose of less than 0.2rems, but the generator table had possibly shielded it. A later reconstruction of the incident produced an estimate of 2rems as the dose to the engineer's trunk surface. It was impossible to estimate the dose to his hands and wrists resulting from direct exposure to the X-ray beam, but the dose received must have been below 500 to 600rems, since no unusual skin effects have subsequently been detected. The incident demonstrates the need for adequate training, frequent monitoring especially when the useful beam is not totally enclosed, and an appreciation of the hazards involved when working with crystallographic equipment generating very intense X-ray beams. The combination of pieces of equipment made by different manufacturers requires particular care. Maintenance and alignment of modern crystallographic apparatus can also be hazardous to inexperienced operators. (U.K.)

  20. Hygiene implications associated with x-ray exposures to dental patients

    An elastic mask worn by patients, then a skeleton encased in plastic, was instrumented with LiF thermoluminescent dosimeters to quantify radiation exposures delivered from full-face diagnostic dental x-rays. Locations of interest included skin surface, eyes, upper and lower teeth and thyroid. Exposures in the 100 mR range were common and a maximum of over 6000 mR was measured in the teeth region during a full-face examination with a periapical unit. In general, exposures received from periapical equipment were several times those obtained from panoramic devices

  1. Determinants of exposure to chemical pollutants in wet X-ray film processing in Iran.

    Kakooei, Hossein; Ardakani, Mehdi B; Sadighi, Alireza

    2007-07-15

    The aim of the current study was to measure glutaraldehyde, acetic acid and sulfur dioxide and levels inside wet x-ray processing areas in a developing country and comparing data with those in developed countries. Forty-five radiographers from 10 educational hospitals affiliated to the Tehran University of Medical Sciences (TUMS) in Tehran, Iran participated in this descriptive-analytical study. Exposure to glutaraldehyde (a constituent of developer chemistry), acetic acid (a constituent of fixer chemistry) and sulfur dioxide (a byproduct of sulfites present in both developer and fixer solutions) was measured in all participants as well as area exposure. Average full-shift exposure to glutaraldehyde, acetic acid and sulfur dioxide were 0.0018, 2.65 and 1.64 mg m(-1), respectively. The results showed that the TUMS radiographers full-shift exposures are generally lower than the American Conference of Governmental Industrial Hygienists (ACGIH) recommended levels. The concentration of glutaraldehyde collected by area sampling (darkroom) was almost five times (0.0104 mg m(-3)) greater than taken by personal sampling. Exposure to the chemical pollutants in the currents study were generally higher than in developed countries. Identification of these key exposure determinants is useful in targeting exposure evaluation and controls to reduce developer and fixer chemicals exposures in the radiology departments. Employing of a digital imaging system that do not involve wet x-ray processing of photographic film would be a useful device for radiographers protection. PMID:19070154

  2. Uncertainties of exposure-related quantities in mammographic x-ray unit quality control

    Breast screening programs operate in many countries with mammographic x-ray units subject to stringent quality control tests. These tests include the evaluation of quantities based on exposure measurements, such as half value layer, automatic exposure control reproducibility, average glandular dose, and radiation output rate. There are numerous error sources that contribute to the uncertainty of these exposure-related quantities, some of which are unique to the low energy x-ray spectrum produced by mammographic x-ray units. For each of these exposure-related quantities, the applicable error sources and their magnitudes vary, depending on the test equipment used to make the measurement, and whether or not relevant corrections have been applied. This study has identified and quantified a range of error sources that may be used to estimate the combined uncertainty of these exposure-related quantities, given the test equipment used and corrections applied. The uncertainty analysis uses methods described by the International Standards Organization's Guide to the Expression of Uncertainty in Measurement. Examples of how these error sources combine to give the uncertainty of the exposure-related quantities are presented. Using the best test equipment evaluated in this study, uncertainties of the four exposure-related quantities at the 95% confidence interval were found to be ±1.6% (half value layer), ±0.0008 (automatic exposure control reproducibility), ±2.3% (average glandular dose), and ±2.1% (radiation output rate). In some cases, using less precise test equipment or failing to apply corrections, resulted in uncertainties more than double in magnitude

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

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

  4. Occupational exposure of medical staff due to diagnostic X-ray examinations in veterinary medicine

    The implementation of the Council directive 96/29 EURATOM and the corresponding national Radiation Protection Ordinance and the X-ray Protection Ordinance coming subsequently into effect led to a changed situation regarding the occupational radiation protection in the medical sector. To reduce the occupational exposure of veterinarians and assisting staff in veterinary radiography is particularly challenging as, in opposite to human radiological examination, the presence of staff is indispensable to restrain the patient. Beyond that the relevant literature reports about too high and/or about unnecessary radiation exposures. To gain a comprehensive knowledge upon the possible exposure of involved staff, the variety of typical examination methods in veterinary clinics and at practitioners had been investigated during the daily routine. Dose measurements were performed for different employees during the examinations taking into account several places of exposure (lens, thyroid, chest, hand, gonad, and feet). Veterinary X-ray diagnostic examinations for pets as well as in equine radiography had been accounted for this study. In total, 101 examination methods, 4.484 accompanied examinations and 53.892 single dose readings resulted in a reliable statistical base to set up a 'Job-Exposure-Matrix' allowing the dose assessment for a variable number and kind of examinations. The 'Job-Exposure-Matrix' is believed to be a useful tool for optimization of occupational radiation exposure of veterinarians by appraising the height of a possible dose, forcing a review of the status quo and triggering the improvement of personal protection by establishing adequate measures. (orig.)

  5. Efficient E-Beam Lithography Exposure Strategies for Diffractive X-ray Optics

    Guzenko, V. A.; Romijn, J.; Vila-Comamala, J.; Gorelick, S.; David, C.

    2011-09-01

    Exposure of structures with rotational symmetry by means of electron beam lithography is not trivial, because the e-beam writers are usually designed to deal with the data defined in Cartesian coordinates. Fabrication of circular nanostructures like Fresnel zone plates (FZPs) for x-ray microscopy applications requires exposures with resolution well below 1 nm. Therefore, special attention has to be paid to the efficient exposure data preparation, which will guarantee required precision and allow keeping the exposure time low. In this article, we describe in detail an optimized strategy that was applied for exposure of FZPs by the Vistec EBPG5000Plus e-beam lithography tool. Direct programming of exposure files allowed us to use fully the capabilities of this e-beam writer to expose efficiently and reproducibly FZPs with desired characteristics in both positive and negative tone resists.

  6. Dual-exposure technique for extending the dynamic range of x-ray flat panel detectors

    This work presents an approach to extend the dynamic range of x-ray flat panel detectors by combining two acquisitions of the same sample taken with two different x-ray photon flux levels and the same beam spectral configuration. In order to combine both datasets, the response of detector pixels was modelled in terms of mean and variance using a linear model. The model was extended to take into account the effect of pixel saturation. We estimated a joint probability density function (j-pdf) of the pixel values by assuming that each dataset follows an independent Gaussian distribution. This j-pdf was used for estimating the final pixel value of the high-dynamic-range dataset using a maximum likelihood method. The suitability of the pixel model for the representation of the detector signal was assessed using experimental data from a small-animal cone-beam micro-CT scanner equipped with a flat panel detector. The potential extension in dynamic range offered by our method was investigated for generic flat panel detectors using analytical expressions and simulations. The performance of the proposed dual-exposure approach in realistic imaging environments was compared with that of a regular single-exposure technique using experimental data from two different phantoms. Image quality was assessed in terms of signal-to-noise ratio, contrast, and analysis of profiles drawn on the images. The dynamic range, measured as the ratio between the exposure for saturation and the exposure equivalent to instrumentation noise, was increased from 76.9 to 166.7 when using our method. Dual-exposure results showed higher contrast-to-noise ratio and contrast resolution than the single-exposure acquisitions for the same x-ray dose. In addition, image artifacts were reduced in the combined dataset. This technique to extend the dynamic range of the detector without increasing the dose is particularly suited to image samples that contain both low and high attenuation regions. (paper)

  7. Device for measuring the exposure time in dental X-ray - Cronox

    Menezes, Claudio J.M.; Santos, Luiz A.P. dos, E-mail: cjmm@cnen.gov.b [Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2009-07-01

    The Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE) developed a test device for monitoring the X-ray beam in dental equipment to its application in quality control programs. This device, called Odontologic Dosimetric Card (CDO of Cartao Dosimetrico Odontologico in Portuguese) uses thermoluminescent dosimeters (TLD) for the measurement of some parameters of the X-ray beam as the entrance surface dose, the peak tension and half value layer (HVL). Radiographic films record the size of the radiation field. However, the TLD does not allow the assessment of exposure time, a parameter that complements the requirements of the Diretrizes de Protecao Radiologica em Radiodiagnostico Medico e Odontologico of Department of Health in Brazil for such equipment. Thus was developed a system based on sensitivity to ionizing radiation of phototransistors for measurement of exposure time when a patient is put in a clinical dental radiography. The system, called CRONOX was sized to be inserted within the CDO. The results showed that the measuring error had developed for less than 3% when compared to reference values obtained with the Tektronix digital oscilloscope, TDS2022 model. The readings obtained with the CRONOX were also compared with the nominal values selected in the X-ray equipment and with the values measured with the instrument of trade PTW Diavolt Universal. The results showed that the measuring device developed showed a maximum deviation of 5.92% on the nominal value selected, while for the instrument of PTW was 17.86%. (author)

  8. Device for measuring the exposure time in dental X-ray - Cronox

    The Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE) developed a test device for monitoring the X-ray beam in dental equipment to its application in quality control programs. This device, called Odontologic Dosimetric Card (CDO of Cartao Dosimetrico Odontologico in Portuguese) uses thermoluminescent dosimeters (TLD) for the measurement of some parameters of the X-ray beam as the entrance surface dose, the peak tension and half value layer (HVL). Radiographic films record the size of the radiation field. However, the TLD does not allow the assessment of exposure time, a parameter that complements the requirements of the Diretrizes de Protecao Radiologica em Radiodiagnostico Medico e Odontologico of Department of Health in Brazil for such equipment. Thus was developed a system based on sensitivity to ionizing radiation of phototransistors for measurement of exposure time when a patient is put in a clinical dental radiography. The system, called CRONOX was sized to be inserted within the CDO. The results showed that the measuring error had developed for less than 3% when compared to reference values obtained with the Tektronix digital oscilloscope, TDS2022 model. The readings obtained with the CRONOX were also compared with the nominal values selected in the X-ray equipment and with the values measured with the instrument of trade PTW Diavolt Universal. The results showed that the measuring device developed showed a maximum deviation of 5.92% on the nominal value selected, while for the instrument of PTW was 17.86%. (author)

  9. Fabrication of 11-nm-Wide Silica-Like Lines Using X-Ray Diffraction Exposure

    Fine silica-like lines with 11 nm width are successfully fabricated using x-ray Fresnel diffraction exposure. X-rays pass a mask of 175-nm-wide lines and 125-nm-wide spaces and form sharp peaks on a wafer coated with a layer of hydrogen silsesquioxane resist (HSQ). By precisely controlling the mask-wafer gap at 10 μm using the laser interferogram method, the fine structures are defined on HSQ. Experimental images are reproduced by a simulation using the one-dimensional beam propagation method. This lithographic technique presents a novel and convenient way to fabricate fine silica-like structures and devices in nano-optical and nanoelectronic applications. (condensed matter: structure, mechanical and thermal properties)

  10. Be Careful When Using X-Ray Exposure Analysis for Polymers

    It is widely accustomed to use x-ray diffraction analysis (XDA) for investigation of the structure of materials and x-ray photoelectron spectroscopy (XPS) for the examination of surface constitution. This technique is considered to be free from radiation-induced artifacts. But it was found very strong effect of the x-ray flux on the surface constitution of the polytetrafluoroethylene (PTFE) that was brought into accord with the mass spectrum of gaseous species evolved during irradiation. The x-ray absorbed dose on the surface was evaluated to be about 106 kGy. It is evident that some sort of similar effects is very probable when using XDA. The x-ray exposure of polymer samples in this case can result in a bulk degradation. The information, that we got, is presented below. The methods of differential scanning calorimetry (DSC) and XDA are usually used for investigation of crystalline structure and crystallinity degree of various materials, including polymers. We used both methods simultaneously to study radiation effects in PTFE. 100 and 50 μm thick PTFE films were irradiated by 60Co gamma-rays at absorbed dose rate 6 Gy/s and temperature 333 K up to dose 300 kGy. The crystallinity degree was measured by the XDA method on the DRON-2 x-ray source through the Cu Kα x-rays scattering in the region of large angles. The source was operated at 30 kV and 30 mA. The crystallinity degree was also measured by DSC method in a DSM-2 calorimeter at scanning rate 12.5 K/min. The dosimetry of such a low energy photon radiation is highly complex. With that end in view, we used a capacitor dosimeter KD-2mp with a diaphragm chamber suitable for the energy range 10-60 keV. At the same time the accumulation of peroxide radical during irradiation of PTFE films was used for dosimetry. The content of radicals was measured by the ESR method on the RE-1306 radiospectrometer. Quite unexpectedly the values of crystallinity degree measured by the two methods for as-received samples of the

  11. Radiation exposure of the population of the GDR by X-ray diagnostics

    The radiation burden of the people of the GDR in relation to biomedical radiography altogether as well as organ doses, gonad doses and genetically significant doses in detail are outlined. The concepts of radiation protection and standards of radiographic examination are demonstrated. Possibilities of influencing radiation exposure by scientifically based indication of X-ray examination, application of new and improvement of usual examination techniques are discussed with regard to quality assurance and control. Proposals concerning the reduction of radiation exposure of the GDR population are presented

  12. Radiation exposure to medical personnel during routine diagnostic or therapeutic X-ray procedures

    The paper presents a statistical analysis of 19 thousand individual measurements of monthly radiation exposures to medical personnel engaged in work with X-ray apparatuses used for routine diagnostic purposes as well as radiotherapy. These measurements used film dosimeters worn over the breast and changed monthly. Exposure distribution patterns were studied and respective typical distributions indentified. From these data, mean radiation doses to selected critical organs were estimated. The radiation burden sustained by personnel was assessed by comparing dose estimates obtained with currently accepted maximum permissible dose levels. (author)

  13. A novel method of microneedle array fabrication using inclined deep x-ray exposure

    We report a novel fabrication method for the microneedle array with a 3-dimensional feature and its replication method; 'Hot-pressing' process with bio-compatible material, PLLA (Poly L-LActide). Using inclined deep X-ray exposure technique, we fabricate a band type microneedle array with a single body on the same material basement. Since the single body feature does not make adhesion problem with the microneedle shank and basement during peel-off step of a mold, the PMMA (Poly-Methyl-MethAcrylate) microneedle array mold insert can be used for mold process which is used with the soft material mold, PDMS (Poly-Di- Methyl-Siloxane). The side inclined deep X-ray exposure also makes complex 3-dimensional features by the regions which are not exposed during twice successive exposure steps. In addition, the successive exposure does not need an additional mask alignment after the first side exposure. The fabricated band type microneedle array mold inserts are assembled for large area patch type out-of-plane microneedle array. The bio-compatible microneedle array can be fabricated to the laboratory scale mass production by the single body PMMA mold insert and 'Hot-pressing' process

  14. Assessment of Targeted and Non-Targeted Responses in Cells Deficient in ATM Function following Exposure to Low and High Dose X-Rays

    Kiuru, Anne; Kämäräinen, Meerit; Heinävaara, Sirpa; Pylkäs, Katri; Chapman, Kim; Koivistoinen, Armi; Parviainen, Teuvo; Winqvist, Robert; Kadhim, Munira; Launonen, Virpi; Lindholm, Carita

    2014-01-01

    Radiation sensitivity at low and high dose exposure to X-rays was investigated by means of chromosomal aberration (CA) analysis in heterozygous ATM mutation carrier and A-T patient (biallelic ATM mutation) lymphoblastoid cell lines (LCLs). Targeted and non-targeted responses to acutely delivered irradiation were examined by applying a co-culture system that enables study of both directly irradiated cells and medium-mediated bystander effects in the same experimental setting. No indication of ...

  15. Development of broadband X-ray interference lithography large area exposure system.

    Xue, Chaofan; Wu, Yanqing; Zhu, Fangyuan; Yang, Shumin; Liu, Haigang; Zhao, Jun; Wang, Liansheng; Tai, Renzhong

    2016-04-01

    The single-exposure patterned area is about several 10(2) × 10(2) μm(2) which is mainly decided by the mask area in multi-beam X-ray interference lithography (XIL). The exposure area is difficult to stitch to a larger one because the patterned area is surrounded by 0th diffraction exposure areas. To block the 0th diffraction beams precisely and effectively, a new large area exposure technology is developed in the Shanghai Synchrotron Radiation Facility by applying an order-sorting aperture with a new in situ monitoring scheme in the XIL system. The patterned area could be stitched readily up to several square centimeters and even bigger by this technology. PMID:27131667

  16. Inactivation of bacteriophage lambda by combined X-ray and U.V.-light exposure

    Extracellular phage lambda has been successively exposed to X-rays and U.V. light. The plaque-forming ability of the irradiated phages was determined on host cells with different repair capacities. No change in sensitivity was found with a pre-treatment of one type of radiation to lethal damage inflicted by the other. This indicates that a prerequisite for an interaction of different types of radiation is either an active metabolism or repair process occurring during the two radiation exposures. (author)

  17. Comparing plasma and X-ray exposure and identifying vulnerable cell parts

    Graham, Bill

    2012-10-01

    Here two issues in plasma medicine that are being addressed in a collaboration between the Centre of Plasma Physics and the School of Pharmacy at Queen's University Belfast and the Plasma Institute at York University UK will be discussed. Recent measurements of the interaction of plasmas created directly in DMEM cell medium and MDAMB-231, a human breast cancer cell line, showed evidence of reduced cell viability and of DNA damage. The same set of experiments were undertaken but with X-ray exposure. A correlation of the dependence on plasma exposure time and X-ray dose was observed which might point the way to dose definition in plasma medicine. We have also been working to identify the cell parts most vulnerable to plasma exposure. In this study a 10 kHz atmospheric pressure non-thermal plasma jet, operating in He/0.5%O2 and characterized to determine the behavior of many of the plasma species, was incident onto the surface of media containing either bacterial strains, in their planktonic and biofilm forms, or isolated bacterial plasmid DNA. The results of measurements to look for changes in plasmid structural conformation, rates of single and double strand breaks, the catalytic activity of certain bacterial enzymes, the peroxidation of lipid content of the bacterial cells, the leakage of ATP and Scanning Electron Microscope (SEM) images will be discussed.

  18. Effect of medical x-ray exposure on subsequent reproductive outcomes in scoliosis patients

    A retrospective cohort study was done which was designed to assess the effects of medical x-ray exposure on cancer incidence among scoliosis patients. Although the primary purpose of the study was to assess cancer incidence, a secondary goal was to investigate whether diagnostic x-ray exposure is related to adverse reproductive events in the female subjects. A series of case-control analyses were done which were designed to assess these effects. Radiation exposure was measured both by total films received and by an estimate of the number of films received and by an estimate of the number of films which involved ovarian irradiation. Radiation appeared to increase a woman's risk of any adverse event in the overall analysis and her risk of a premature or low birth weight infant in the separate analyses. Radiation did not appear to be related to spontaneous abortion, complications of pregnancy or delivery or birth defects, although the results of the pregnancy complications analysis was suggestive

  19. Occupational exposure of medical staff due to diagnostic X-ray examinations in veterinary medicine

    Mergel, E.; Feige, S. [Gesellschaft fuer Anlagen- und Reaktorsicherheit mbH (GRS) (Germany); Haeusler, U. [Bundesamt fuer Strahlenschutz (BfS), Salzgitter (Germany)

    2007-07-01

    The implementation of the Council directive 96/29 EURATOM and the corresponding national Radiation Protection Ordinance and the X-ray Protection Ordinance coming subsequently into effect led to a changed situation regarding the occupational radiation protection in the medical sector. To reduce the occupational exposure of veterinarians and assisting staff in veterinary radiography is particularly challenging as, in opposite to human radiological examination, the presence of staff is indispensable to restrain the patient. Beyond that the relevant literature reports about too high and/or about unnecessary radiation exposures. To gain a comprehensive knowledge upon the possible exposure of involved staff, the variety of typical examination methods in veterinary clinics and at practitioners had been investigated during the daily routine. Dose measurements were performed for different employees during the examinations taking into account several places of exposure (lens, thyroid, chest, hand, gonad, and feet). Veterinary X-ray diagnostic examinations for pets as well as in equine radiography had been accounted for this study. In total, 101 examination methods, 4.484 accompanied examinations and 53.892 single dose readings resulted in a reliable statistical base to set up a 'Job-Exposure-Matrix' allowing the dose assessment for a variable number and kind of examinations. The 'Job-Exposure-Matrix' is believed to be a useful tool for optimization of occupational radiation exposure of veterinarians by appraising the height of a possible dose, forcing a review of the status quo and triggering the improvement of personal protection by establishing adequate measures. (orig.)

  20. Evaluation of image quality and appropriate X-ray exposure of a flat panel detector

    We evaluated image quality and necessary patient exposure when using the CXDI-11 (Canon Inc.) flat panel detector (FPD). This detector, which consists of a rare earth fluorescent screen (Gd2O2S: Tb) and amorphous silicon sensor, was compared with the FCR-5000 (Fuji Film Medical Co., Ltd.) CR and the UR-3/HGM2 (Fuji Film Medical Co., Ltd.) film-screen (F/S) combination. Comparisons of both physical imaging characteristics and clinical image quality were carried out. The final MTF of the FPD was found to be similar to or better than those of the CR and F/S systems. For identical exposures, the overall Wiener spectrum of the FPD was found to be slightly poorer than that of the F/S combination. The NEQ of the FPD was found to be similar to or better than those of the CR and F/S systems. Comparison of chest images showed that the FPD produced images with quality comparable to or higher than those of the CR system. Similarly, evaluation of abdominal and bone images using a 5-scale method showed that the FPD produced images with quality comparable to or higher than those of the CR system. As with CR, the x-ray quantum mottle in FPD images becomes noticeable at low exposures. Clinical images were therefore taken with a 30% increase in exposure, giving a Wiener spectrum for the FPD images similar to that obtained with the F/S images. This is probably not a significant increase in exposure, given the improvement in image quality and increased ease of use provided by the CXDI system. Further, future improvements in hardware and image processing may allow images to be taken with the same exposure used for F/S images. Our evaluation of both image quality and x-ray exposure has therefore indicated the value of the FPD in the clinical environment. (author)

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

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

  2. Radiation exposures of cancer patients from medical X-rays: How relevant are they for individual patients and population exposure?

    X-ray procedures have a substantial impact not only on patient care but also on man-made radiation exposure. Since a reliable risk-benefit analysis of medical X-rays can only be performed for diagnosis-related groups of patients, we determined specific exposure data for patients with the ten most common types of cancer. For all patients with the considered cancers undergoing medical X-ray procedures in a maximum-care hospital between 2000 and 2005, patient- and examination-specific data were retrieved from the hospital/radiology information system. From this data, the cumulative 5-year effective dose was estimated for each patient as well as the mean annual effective dose per patient and the mean patient observation time for each cancer site. In total, 151,439 radiographic, fluoroscopic, and CT procedures, carried out in 15,866 cancer patients (age, 62 ± 13 years), were evaluated. The mean 5-year cumulative dose varied between 8.6 mSv (prostate cancer) and 68.8 mSv (pancreas cancer). Due to an increasing use of CT scans, the mean annual effective dose per patient increased from 13.6 to 18.2 mSv during the 6-year period. Combining the results obtained in this study for a particular hospital with cancer incidence data for Germany, we estimated that cancer patients having X-ray studies constitute at least 1% of the population but receive more than 10% of the total effective dose related to all medical X-ray procedures performed nationwide per year. A large fraction of this dose is radiobiologically ineffective due to the reduced life expectancy of cancer patients.

  3. Estimation of patient exposure dose in the X-ray diagnoses

    Fundamental concept to asses the patient dose and its calculating methods are explained for X-ray examinations like radiography, abdominal fluoroscopy and CT, from the technological aspect of radiological protection. Justification of medical exposure, optimization of its dose and assessment of absorbed dose in patients are essentially based on guides by ICRP, IAEA and ICRU, and their application to Japanese standard has been being conducted. The numerical dose determination (NDD) method has been widely used by calculating the patient entrance air kerma using parameters of the tube voltage, tube current-time product, distance from the focus to skin, total filtration and back scatter. Coefficients for NDD are obtained from the tube voltage and Al filtration of X-ray spectrum with an empirical formula. The add-in software (NDD-Modify) in MS-Excel later developed can conveniently give the rough patient dose and is utilized in such facilities as having no dosimeter. radiology information system (RIS) equipped in the X-ray machine displays the estimated patient dose by NDD base and the actual output dose before and after imaging, respectively. This NDD comes from standardized coefficients of parameters above for 5 x 5-30 x 30 cm irradiation sizes using their corresponding back scatter coefficients calculated by Monte Carlo techniques for modeled structures of the tube, multi-leaf diaphragm and water phantom, and has been also able to be applied in the personal computer (PC) with the software estimation of patient dose (EPD). The PC-based Monte Carlo program for calculating organ doses of patients undergoing medical X-ray examinations (PCXMC) of radiology and fluoroscopy is written with Delphi Object Pascal code; is composed from the photoelectric absorption, coherent and incoherent scatters; and widely used at present. imaging performance assessment of CT scanners (ImPACT) is the excel bookfile, usable to calculate the organ dose and effective dose. In future, patient

  4. An old/new idea for reducing exposure to x-rays

    In 1925 the patient's exposure to x-radiation was reduced 50 percent by the application of emulsion to both sides of the dental film. Another similar reduction is possible when the layers of emulsion are once again doubled. The authors have rediscovered this idea and tested it. A double film packet containing films which are hinged on one side for proper reorientation after developing was produced. The films were exposed to half the radiation given to normal packets. It was found that density, contrast, and definition were all comparable to normal exposures when allowances were made for an additional layer of blue-tinted film base. In addition to reduced exposure to x-rays, the folded-film technique gives a second view of the exposed area. An underexposed view is obtained by viewing either side of the folded film alone. This underexposed view offers some details not seen on fully exposed films

  5. X-ray diagnosis facility for radiographs containing means for organ-programmed adjustment of the exposure parameters and on automatic X-ray exposure system

    In front of and behind the patient there are detectors, the first one standing between the patient and the X-ray tube. In order to measure the X-ray transparency of the patient, a signal representing the dose rate is formed by the detector in front of the patient which is supplied to a comparator together with the signal from the detector behind the patient. From both signals, the comparator forms a signal of the actual value of the transparency signal. The measure for the dose rate is now determined from current and voltage of the X-ray tube. (RW)

  6. Relationships between exposure dose and additional filter thickness in the X-ray diagnosis

    For the purpose of reduction of exposure dose in the X-ray diagnosis, authors examined the effect of additional filter thickness on the dose. The apparatus was Toshiba KXO-30F with filter thickness of 2.3 mm Al. For the additional filters, aluminium plates of 0.5 mm and 1.0 mm thickness were used. Dosimetry was done with VICTOREEN RADOCON 500 and with the ionization chambers VICTOREEN RADOCON 550-5 and 30-330, and X-ray analysis for measuring effective energy, with KYOKKO MODEL 100. Phantoms were polystyrene plates and manikin (Kyotokagakuhyohon PB-10). The incident surface dose and irradiation time were examined with varied phantom thickness. Further, the influence of the additional filter thickness was examined on the half-value thickness and effective energy of tube voltage. When the additional filter thickness was more than 10 mm Al, the incident surface dose was found hardly changed and irradiation time was 2 times as long. At 10.0 mm Al thickness, the thicker was the phantom, the smaller were the exposure dose and irradiation time. The thicker was the additional filter, the lower was the resolution of the site necessary to enhance the contrast, such as bone. Thus, the reduction of the dose requires the appropriate selection of the suitable tube voltage, additional filter thickness and sensitive film. (K.H.)

  7. Effects of pre-natal X-ray exposure on learning behaviour of mice

    The authors investigated whether prenatal X-raying affects the learning behaviour of mice. For this purpose they irradiated mice of strain C57BL/6Ffm with 130 r at different points of the fetal phase. Unirradiated mice served as controls. The animals underwent two learning test series of 14 days each teaching them optical signs. The results of the test series show a distinctly inferior learning ability in the animals exposed to pre-natal irradiation as compared to unirradiated controls. The extent of the reduction of the learning ability depends on the stage of the pregnancy at the time of X-ray exposure. The greatest difference as compared to non-irradiated mice occurred in the animals irradiated at the earliest stage (13th/14th day of pregnancy). The results of the other test groups (15th/16th and 17th/18th day of pregnancy) exhibited less distinct, but still significant differences to the controls. Exposure at the latest period (17th/18th day) coincided with the smallest difference. (orig./MG)

  8. Radiation hygiene in medical X-ray imaging. Pt. 3. Radiation exposure of patients and risk assessment

    The frequency of X-ray examinations in Germany and the resulting radiation exposure is amongst the highest in comparison with other European countries. To reduce medical radiation exposure and to safeguard radiation protection regulations, the X-ray ordinance stipulates a justification of each individual X-ray application. The justification principle means that the X-ray application should produce sufficient health benefit to offset the radiation risk. Such a benefit-risk assessment needs an adequate estimation of radiation risk. The aim of this paper is to explain the principles of benefit-risk assessment for different situations (e.g. healthcare and screening). The basics and concepts of radiation effects and radiation epidemiology as well as examples of risk estimation and benefit-risk assessments are given. (orig.)

  9. Exposure station with precision scanning stage for deep x-ray lithography

    An exposure station with a precision scanning stage has been designed and constructed for use at the Advanced Photon Source for deep x-ray lithography. The precision scanning stage consists of four motion stages--two translations and two rotations. There is a theta rotation in the horizontal plane at the base, which allows precise setting of the angle of inclination of the x-rays to the substate for inclined, trapezoidal, and conical exposures. The horizontal X travel is mounted on the theta rotation and provides accurate positioning in the horizontal direction to allow field stitching and general alignment. The vertical Z travel is mounted on the X travel and is used to scan the mask and substrate through the x-rays repeatedly during exposure. The phi rotation is mounted on the Z travel and can be used for generating pyramidal and conical structures. Total absolute worst case angular error due to the sum of the stage motions including theta axis wobble, X axis pitch, yaw, and roll, and Z axis pitch, yaw, and roll should be 100 microradians. The entire scanning stage is mounted on a precision optical table that can be aligned to within 5 microns in position and 5 microradians in angle with full 6-degrees of freedom. The motion stages are driven by stepping motors for positioning and DC servo motors for the vertical Z scan and include encoder feedback. The motors are controlled using the EPICS distributed control system. All of the other beamline components and the optical table are also controlled by EPICS, and this allows complete integration of the operation of the scanning stage with the optical table, filters, slits, mirrors, and shutters to provide the user with full control of the exposure from a program running on a computer workstation. A temperature-controlled fixture is mounted on the f rotation, and the mask and substrate to be exposed are held by this fixture. A small housing with a Kapton window mounts onto the fixture to enclose the mask and substrate

  10. Exposure station with precision scanning stage for deep x-ray lithography

    Mancini, Derrick C.; DeCarlo, Francesco; Lai, Barry

    1997-07-01

    An exposure station with a precision scanning stage has been designed and constructed for use at the Advanced Photon Source for deep x-ray lithography. The precision scanning stage consists of four motion stages—two translations and two rotations. There is a theta rotation in the horizontal plane at the base, which allows precise setting of the angle of inclination of the x-rays to the substate for inclined, trapezoidal, and conical exposures. The horizontal X travel is mounted on the theta rotation and provides accurate positioning in the horizontal direction to allow field stitching and general alignment. The vertical Z travel is mounted on the X travel and is used to scan the mask and substrate through the x-rays repeatedly during exposure. The phi rotation is mounted on the Z travel and can be used for generating pyramidal and conical structures. Total absolute worst case angular error due to the sum of the stage motions including theta axis wobble, X axis pitch, yaw, and roll, and Z axis pitch, yaw, and roll should be 100 microradians. The entire scanning stage is mounted on a precision optical table that can be aligned to within 5 microns in position and 5 microradians in angle with full 6-degrees of freedom. The motion stages are driven by stepping motors for positioning and DC servo motors for the vertical Z scan and include encoder feedback. The motors are controlled using the EPICS distributed control system. All of the other beamline components and the optical table are also controlled by EPICS, and this allows complete integration of the operation of the scanning stage with the optical table, filters, slits, mirrors, and shutters to provide the user with full control of the exposure from a program running on a computer workstation. A temperature-controlled fixture is mounted on the f rotation, and the mask and substrate to be exposed are held by this fixture. A small housing with a Kapton window mounts onto the fixture to enclose the mask and

  11. Radiological protection in X-ray diagnosis: How to minimize the patient exposure in X-ray diagnosis

    The principles involved in the radiation protection and the radiographic process are discussed. An adequate systematic work is presented, to achieve the main goal of the Radiation Protection that is, to irradiate the patient and the staff with lowest possible exposure. (M.A.C.)

  12. DNA Topoisomerase-I Inhibition due to Exposure to X-Rays

    In events such as radiological terrorism, accidents involving radioactive materials and occupational exposures, there is a great need to identify exposures to relatively low radiation levels. In many situations, the evaluation of radiation doses is not possible using physical dosimeters as they are not worn, and it is desirable to achieve this based on sensitive biomarkers (1, 2, 3). DNA Topoisomerase-I (Topo-I) is an essential nuclear enzyme that is responsible for the topological state of the DNA. The enzyme is involved in a variety of DNA transactions, including replication, transcription, recombination and DNA repair (4,5). The aim of the present work was to investigate the influence of X-ray radiation on the catalytic activity of this enzyme, and to evaluate its applicability as a biological dosimeter

  13. Medical X-ray doses' contributions to the ionizing radiation exposures of atomic-bomb survivors

    Doses from diagnostic radiological examinations were measured in order to evaluate the radiation risks of atomic-bomb survivors in Hiroshima and Nagasaki. Using a phantom human, doses to the active bone marrow, gonads, salivary glands, thyroid gland, lung, breast, stomach and colon were determined by type of examination and by examination site. The results of this dosimetry program will aid in estimating the diagnostic exposure doses received by each participant in the Adult Health Study of the Radiation Effects Research Foundation. The current results of these dosimetry studies also indicate that the effects of A-bomb exposure cannot be reliably assessed unless medical X-ray doses are carefully incorporated into these long-term evaluations. (author) 51 refs

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

    Rijn, Rick R. van; Wittenberg, Rianne [Academic Medical Centre Amsterdam, Department of Radiology, Amsterdam Zuid-Oost (Netherlands); Boot, Annemieke; Sluis, Inge M. van der; MuinckKeizer-Schrama, Sabine M.P.F. de [Erasmus MC-Sophia Children' s Hospital, Department of Paediatric Endocrinology, Rotterdam (Netherlands); Heuvel-Eibrink, Marry M. van den [Erasmus MC-Sophia Children' s Hospital, Department of Paediatric Haematology/Oncology, Rotterdam (Netherlands); Lequin, Maarten H. [Erasmus MC-Sophia Children' s Hospital, Department of Paediatric Radiology, Rotterdam (Netherlands); Kuijk, Cornelis Van [University Medical Centre ' Radboud' , Department of Radiology, Nijmegen (Netherlands)

    2006-03-15

    In recent years interest in bone densitometry in children has increased. To evaluate the clinical application of digital X-ray radiogrammetry (DXR) and compare the results with those of dual-energy X-ray absorptiometry (DXA). A total of 41 children with acute lymphoblastic leukaemia (ALL) and 26 children with growth hormone deficiency (GHD) were included in this longitudinal study. Radiographs of the left hand were obtained and used for DXR. DXA of the total body and of the lumbar spine was performed. In both study populations significant correlations between DXR and DXA were found, and, with the exception of the correlation between DXR bone mineral density (DXR-BMD) and bone mineral apparent density in the GHD population, all correlations had a P-value of <0.001. During treatment a change in DXR-BMD was found in children with GHD. Our study showed that DXR in a paediatric population shows a strong correlation with DXA of the lumbar spine and total body and that it is able to detect a change in BMD during treatment. (orig.)

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

    In recent years interest in bone densitometry in children has increased. To evaluate the clinical application of digital X-ray radiogrammetry (DXR) and compare the results with those of dual-energy X-ray absorptiometry (DXA). A total of 41 children with acute lymphoblastic leukaemia (ALL) and 26 children with growth hormone deficiency (GHD) were included in this longitudinal study. Radiographs of the left hand were obtained and used for DXR. DXA of the total body and of the lumbar spine was performed. In both study populations significant correlations between DXR and DXA were found, and, with the exception of the correlation between DXR bone mineral density (DXR-BMD) and bone mineral apparent density in the GHD population, all correlations had a P-value of <0.001. During treatment a change in DXR-BMD was found in children with GHD. Our study showed that DXR in a paediatric population shows a strong correlation with DXA of the lumbar spine and total body and that it is able to detect a change in BMD during treatment. (orig.)

  16. Comparative study of spermatogonial survival after X-ray exposure, high LET (HZE) irradiation or spaceflight

    Sapp, W. J.; Williams, C. S.; Williams, J. W.; Philpott, D. E.; Kato, K.; Miquel, J. M.; Serova, L.

    1992-01-01

    Spermatogonial cell loss has been observed in rats flown on Space Lab 3, Cosmos 1887, Cosmos 2044 and in mice following irradiation with X-ray or with HZE particle beams. Spermatogonial loss is determined by cell counting in maturation stage-6 seminferous tubules. With the exception of iron, laboratory irradiation experiments (with mice) revealed a similar pattern of spermatogonial loss proportional to the radiation dose at levels less than 0.1 Gy. Helium and argon irradiation resulted in a 5-percent loss of spermatogonia after only 0.01 Gy exposure. Significant spermatogonial loss (45 percent) occurred at this radiation level with iron particle beams. The loss of spermatogonia during each spaceflight was less than 10 percent when compared to control (nonflight) animals.

  17. X-ray findings in roofers with long-term exposure to asbestos cement fine dusts

    In 404 roofers with long-term exposure of asbestos-cement fine dust we studied the possible fibrogenous effects on lung and pleura by chest radiographs. The standardfilm sets of the ILO U/C 1971 and ILO 80/BRD X-ray classification of pneumoconiosis were used. 410 non-asbestos-exposed craftsmen and workers of several industries served as control group. Roofers show in n = 58 cases (14,4%) significantly increased small irregular opacities of the size 's' and 't' with the profusion 1/0 (n = 53) and 1/1 (n = 5). Furthermore up to now, 3 cases of lung-cancer in our cohort have been occured. Our findings indicate the nessecity of further preventive measures on construction sites regarding the asbestos-cement problem. (orig.)

  18. X-ray findings in roofers with long-term exposure to asbestos cement fine dusts

    Stauder, B.; Breuer, G.; Greven, U.; Woitowitz, R.H.; Roedelsperger, K.; Woitowitz, H.J.

    1982-11-01

    In 404 roofers with long-term exposure of asbestos-cement fine dust we studied the possible fibrogenous effects on lung and pleura by chest radiographs. The standardfilm sets of the ILO U/C 1971 and ILO 80/BRD X-ray classification of pneumoconiosis were used. 410 non-asbestos-exposed craftsmen and workers of several industries served as control group. Roofers show in n = 58 cases (14,4%) significantly increased small irregular opacities of the size 's' and 't' with the profusion 1/0 (n = 53) and 1/1 (n = 5). Furthermore up to now, 3 cases of lung-cancer in our cohort have occured. Our findings indicate the necessity of further preventive measures on construction sites regarding the asbestos-cement problem.

  19. Radiation exposure during x-ray examinations in a large paediatric hospital in Serbia

    Objective of this work is to evaluate radiation exposure from X-ray examinations in a large paediatric hospital in Serbia, including radiographic, fluoroscopic and computed tomography (CT) examinations in four age groups: 0 -1, 1-5, 5-10 and 10-15 y. Incident air kerma was assessed for the following radiographs: chest (AP, PA, LAT), spine (AP, LAT), pelvis (AP), urinary tract (AP, PA) and skull (AP, PA, LAT). Kerma-area product was measured for the fluoroscopy examinations: barium swallow, barium meal, barium enema and micturating cystography. Dose in CT was assessed in terms of volume CT dose index and dose length product for examinations of the head, chest and abdomen. The collected data were compared with other similar studies, which indicated a need to expand such survey to other paediatric hospitals in Serbia. (authors)

  20. Variations in film exposure, effective kVp, and HVL among thirty-five dental x-ray units

    Speed group ''E'' dental films were exposed in thirty-five dental x-ray units and processed under rigidly controlled conditions. The exposure, in milliroentgens required to produce an overall film density between 0.85 and 1.05 density units at the 9 mm. step of an aluminum step-wedge, ranged from 94 to 186 mR. The wide range in normalized exposure required to produce a standard density of 1.0 was associated with half-value layer and effective operating kilovoltage in only a general way. The half-value layer of thirty-five dental x-ray units ranged from 1.9 to 2.9 mm. Al, and their effective operating kilovoltages ranged from 62 to 77 kVp when units were set at 70 kVp. The exposure required to produce a specific radiographic density depended largely on the individual characteristics of the x-ray unit used

  1. Signal-to-noise and radiation exposure considerations in conventional and diffraction x-ray microscopy

    Huang, Xiaojing; Miao, Huijie; Steinbrener, Jan; Nelson, Johanna; Shapiro, David; Stewart, Andrew; Turner, Joshua; Jacobsen, Chris

    2009-01-01

    Using a signal-to-noise ratio estimation based on correlations between multiple simulated images, we compare the dose efficiency of two soft x-ray imaging systems: incoherent brightfield imaging using zone plate optics in a transmission x-ray microscope (TXM), and x-ray diffraction microscopy (XDM) where an image is reconstructed from the far-field coherent diffraction pattern. In XDM one must computationally phase weak diffraction signals; in TXM one suffers signal losses due to the finite n...

  2. Some points of the X-ray pattern of acute viral primary pneumonia caused by acute respiratory disease viruses

    An analysis is made of the results of the X-ray studies as well as of the virological and serological tests in 225 out-patients consulted in the first days of their complaints. A predominance of the viral (70.2%) over the viral-bacterial primary pneumonia is established. The acute viral primary pneumonia are caused mostly by single influenza viruses and more rarely - by single respiratory viruses; in the cases of combined influenza viruses influenza-influenza viruses prevail over the influenza-respiratory ones. The morphological changes in pneumonia due to isolated single influenza viruses involve mostly the interstitium and are projected on X-ray as patchy and stripped densities. The inflamatory changes in pneumonia caused by combined influenza viruses affect both ihe interstitium and the broncho-alveolar substrate of the lungs; they are manifested in two roentgenologic forms: creeping (migrating) and fusing (confluent). In viral-bacterial pneumonia the changes affect mostly the lobe. The right lung and the lower parts of the both lungs are affected in most cases. 5 figs., 21 refs

  3. Hematological effects of unilateral and bilateral exposures of dogs to 300-kVp X rays

    Accidental exposures to ionizing radiation from external sources usually result in an inhomogeneous dose distribution rather than a homogeneous total-body irradiation (TBI). To study the hematological effects of an inhomogeneous dose distribution, dogs were unilaterally exposed to a beam of 300 kVp X rays (HVL = 3.8 mm Cu) with their left side directed to the source. The entrance and exit surface doses were 3.8 Gy and 0.9 Gy, respectively. Dose measurements performed in bone marrow spaces of various bones revealed a maximum of 3.1 Gy in the head of the left humerus and a minimum of 0.9 Gy in the right iliac crest. Based on survival for granulocyte-macrophage progenitor cells (GM-CFC) determined in different bone marrow sites 24 h after the exposure, the dose-dependent reduction ranged from 0.44 to 16% of the control values. The regeneration of the GM-CFC compartments in the various bone marrow spaces showed patterns which were independent of each other up to Day 28. Values were normal again at Day 125 after exposure. For comparative purposes, three dogs were exposed bilaterally to achieve a homogeneous dose distribution. They received a TBI of 2.4 Gy, which according to previous calculations should have caused the same systemic damage to the GM-CFC compartment as the unilateral exposure. The peripheral blood cell changes, including the GM-CFC, and the colony stimulating activity in the serum showed a similar pattern for both exposures. These findings support the hypothesis that the overall survival fraction of progenitor cells in the bone marrow is the main determinant of the blood cell changes, independent of the anatomical distribution

  4. Bone X-Ray (Radiography)

    Full Text Available ... and x-rays. A Word About Minimizing Radiation Exposure Special care is taken during x-ray examinations ... patient's body not being imaged receive minimal radiation exposure. top of page What are the limitations of ...

  5. A survey on radiation exposure of primary operators from interventional X-ray procedures

    To understand the situation of radiation exposure to primary operators in the interventional X-ray procedures, a pilot survey was conducted for the 5 most frequently performed procedures in Shanghai in 2011. The distributions of entrance-surface air kerma (ESAK) were measured with thermoluminescent dosimeters (TLD) in 125 primary operators conducting the 5 procedures in 10 hospitals in Shanghai, and the equivalent doses (HT) for eye lens and extremity as well as the effective dose (E) were estimated. The results showed that the mean ESAKs were usually larger than 10 μGy for unshielded eye lens and extremity in each procedure, and the annual HT for unshielded eye lens exceeded 10 mSv in some procedures, such as the coronary angiography (CA) and angioplasty (PTCA). The mean annual effective doses were estimated to be 0.7–10.4 mSv among the 5 procedures, however, the values varied with different calculation algorithms. -- Highlights: ► It is the first and well designed survey in Shanghai, P. R. China. ► Under the apron, the exposure to left side and right side of chest are also different. ► The doses vary a lot with different calculating algorithms for some procedures. ► Further studies are needed for accurate measurement and assessment of the doses

  6. Genetic risks following exposure of maternal and paternal germ cells to X-rays

    To determine the risk, after paternal exposure to X-rays, male mice (NMRI strain) were irradiated with 20 and 200 rad and mated with non-irradiated females from day 2 to day 160 p.r. Embryos were then obtained from the fertilized females, 1 day and 9.5 days after detection of a vaginal plug, and preparations were then made for chromosomal analysis, using G-banding. In both, early and later embryos, we found aneuploid as well as structurally abnormal karyotypes. The incidence of aneuploidy after paternal exposure to 200 rad was not statistically different from the 20 rad-group. In the pronuclei we found a higher incidence of chromosomally abnormal embryos than in the 9.5 days-old embryos. The radiation-effect on oocytes was studied in three species: mouse (NMRI), Chinese hamster and the Djungarian hamster. All females were irradiated 2 hrs. after HCG and chromosomes analysed from ovulated oocytes at metaphase II, that means immediately after the first meiotic division. From these experiments we suggest that irradiation of mammalian oocytes may: 1) Increase the incidence of genome mutations; 2) Has no effect whatever; 3) Decrease the incidence of genome mutations, as for example, in non-disjunction. Factors such as species, strain, age, as well as actual hormonal constitution, may therefore contribute to the process of radiation-induced genome mutations. (orig./MG)

  7. Breast cancer in women with x-ray exposure: models of dose, time, and host susceptibility

    Acute postpartum mastitis (APM) is an inflammatory/infectious condition of the breast, occurring commonly at childbirth or during lactation. A series of 600 women who received x-ray therapy for APM during the 1940s or 1950s have been followed up by mail questionnaire, with medical verification of pertinent conditions, to ascertain their incidence of breast cancer. The groups have been followed for up to 45 years, with an average of 29 years. The relative risk of breast cancer, adjusted for age and interval since irradiation (or an equivalent entry definition for controls) was 3.2 for the irradiated breasts. The dose-response curve appeared to be essentially linear, except for a diminution of risk at high doses (≥ 700 rad). The fact that there were no breasts with doses between zero and 50 rad, however, means it was not possible to evaluate the curvature with the maximum contrast between low and high doses. The dose fractionation analyses showed that the number of dose fractions or the number of days between fractions had no apparent effect upon breast cancer risk, but there was a suggestion that lower doses per fraction led to a higher risk, which runs counter to what one would expect based on radiobiological theory. However, a Cox regression analysis, controlling for total breast dose, did not yield a significant effect for any of the fractionation variables

  8. Fabrication of open-top microchannel plate using deep X-ray exposure mask made with silicon on insulator substrate

    Fujimura, T; Etoh, S I; Hattori, R; Kuroki, Y; Chang, S S

    2003-01-01

    We propose a high-aspect-ratio open-top microchannel plate structure. This type of microchannel plate has many advantages in electrophoresis. The plate was fabricated by deep X-ray lithography using synchrotron radiation (SR) light and the chemical wet etching process. A deep X-ray exposure mask was fabricated with a silicon on insulator (SOI) substrate. The patterned Si microstructure was micromachined into a thin Si membrane and a thick Au X-ray absorber was embedded in it by electroplating. A plastic material, polymethylmethacrylate (PMMA) was used for the plate substrate. For reduction of the exposure time and high-aspect-ratio fast wet development, the fabrication condition was optimized with respect to not the exposure dose but to the PMMA mean molecular weight (M.W.) changing after deep X-ray exposure as measured by gel permeation chromatography (GPC). Decrement of the PMMA M.W. and increment of the wet developer temperature accelerated the etching rate. Under optimized fabrication conditions, a microc...

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

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

    2006-01-01

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

  10. Determination of energy absorbed during X-ray exposure of the forearm by means of thermoluminescent dosimetry

    LiF dose meters were used to determine radiation doses in conventional X-ray diagnostic pictures of the forearm. The paper describes a method for determining integral doses by using these dose meters. It describes in detail how a phantom forearm apt for the purpose is to be made. In the Federal Republic of Germany, malignant growth incidence due to X-ray pictures of the forearm is enhanced by about .01 cases each year. The malignant growth incidence rate caused by X-ray diagnostic measures is low. It is therefore generally justified to neglect limbs in exemplary studies of radiation exposure. All calculations and considerations took into account that all possible radiation protection measures have been duly applied. (orig./DG)

  11. A new device to reduce x-ray exposure of the examiner during the procedure of retrograde urethrography

    The use of the new device ''Sanii-Horuda'' designed to hold the patient's penis indirectly during urethrography enabled the examiner to avoid unnecessary direct exposure of x-ray. In the ordinary way in which the patient's penis was held directly with the examiner's left hand, as much as 670 mRems of x-ray were recorded at the examiner's left wrist with two exposure (anteroposterior and oblique view). It is possible from the report of Koga and his associates that the examiner's left hand within the field of direct exposure would receive more than 1,000 mRems for each patient. Our study demonstrated that the use of the new device reduced the examiner's exposure to null. In addition, this device was not only valuable but also more successful in urethrography. (auth.)

  12. X-ray exposure hazards for physicians performing ablation procedures and device implantation

    Marinskis, Germanas; Bongiorni, Maria Grazia; Dagres, Nikolaos;

    2013-01-01

    The purpose of the survey was to evaluate physician's and authorities policies and clinical practices when using occupational X-ray during ablation procedures and device implantation. This survey shows infrequent use of lead gloves, radiation absorbing pads, and lead glass cabins, but increasing ...... use of three-dimensional mapping systems to decrease X-ray radiation hazards. Digital fluoroscopy with decreased frame rate is not used by approximately one-third of responding centres....

  13. X-ray diagnostic features of acute bleeding ulcers of the stomach and duodenum

    The paper is based on the analysis of clinical, X-ray, and morphological studies in 74 patients with massive gastrointestinal hemorrhage. The paper presents the specific features of X-ray studies of patients with bleeding gastroduodenal ulcers. X-ray studies shout be twice performed in these patients. The first study is conducted if gastroscopic findings are unclear, the repeated one is carried out while assessing changes in disease regression. X-ray diagnosis of bleeding ulcers is determined by their sites and the nature of an ulcerous process. The X-ray diagnosis of chronic callous gastric ulcers accompanied by hemorrhage was based on the detection of two direct symptoms of a niche on the gastric outlines and configuration and an inflammatory mound on the gastric outline and configuration. That of chronic bleeding ulcers of the duodenal bulb is based not only on searches niche, but other signs of the disease - the deformed organ, and the magnitude of a periprocess. 10 refs., 5 figs

  14. Dosimetric studies in children and adolescents using thermoluminescence dosemeters following radiation exposure from panoramic dental X-ray units

    For the determination of the somatic radiation exposure of children and adolescents by X-ray films with the status X panorama X-ray unit personal dosimetric measurements were carried out by means of thermoluminescence dosemeters (LiF and CaSO4) in 46 patients aged 7 to 16 years. The non-screen film 'ORWO TF 13' and the screen film 'ORWO TF 2' in connection with flexible intensifying screens were used. During the exposure the dosemeters were always fixed at the same measuring points being situated within or outside the mouth of the patient. The maximum radiation exposure was registered at those points where the transparent window of the hollow anode introduced into the mouth of the patient was directly opposite to the palatal and lingual, mucosa resp. With a maxillary or mandibular panorama film and the use of non-screen films doses of 60 to 80 mGy (6 - 8 rd) were determined. Using TF 2 screen films in connection with flexible intensifying screens the values for exposure time and radiation dose could be decreased by more than 50%. Basing on these results not only a strict indication but also the use of intensifying screens have to be required for the performance of radiodiagnostical examination with status X panorama X-ray units. (author)

  15. Improvement of Contrast in Digital X-ray Images Considering Exposure Dose for Stout Patients Undergoing Fluorography Chest Screening

    Due to high level of tuberculosis in Ukraine, the fluorography chest screening is the most frequent diagnostic procedure which is performed annually for adult population and contributes to collective effective dose. During the diagnostic examination, the people with high body mass index obtain higher exposure dose, compared to average patients. The higher exposure dose is required for receiving diagnostic X-ray images with sufficient visual quality parameters. In present study, the approach in reduce of exposure dose for patients with high body mass index was explored in close to clinical fluorography examination conditions with application of contrast improvement methods

  16. MODERN PECULIARITIES OF THE MEDICAL EXPOSURE LEVELS FORMING OF THE TATARSTAN REPUBLIC POPULATION DURING X-RAY PROCEDURES IMPLEMENTATION

    S. A. Ryzhkin

    2015-01-01

    Full Text Available The purpose. The purpose of the investigation is an assessment of the peculiarities of forming and registration of the collective doses of patients and the population of the Tatarsatan Republic (RT from medical exposure and the development of measures for optimization of this radiation factor.Materials and methods. The analysis is based on the forms of the Federal statistical observation № 3-DOZ «Data on the exposure doses to patients obtained during medical radiological examination» (form № 3-DOZ and radiation-hygienic passports of RT for the period from 2006 to 2013.The results. Annually in RT there is an increase of the number of performed X-ray procedures, which reached the value of 6279696 (1.64 procedures per resident per year in 2013. During the reporting period (from 2006 to 2013 the structure of the performed X-ray procedures has also changed. It is observed that the percentage of fluorography procedures in the overall structure decreased from 41.3% to 31.3% at the same time the level of absolute value of annually performed fluorography procedures is stable. There is an increase in the absolute number of radiographic procedures performed during the period from 2578754 to 4072810 X-rays per year, that is 1.58 times higher. Absolute and relative values related to X-ray fluoroscopy examinations decreased from 1.1% to 0.7%. In contrast, the absolute number of annually performed X-ray computed tomography examinations (CT has increased over the period by 3.3 times and percentage of CT in overall structure of X-ray procedure is 2.7%. The number of special investigations has increased in 2.1 times, but the relative value remained at average level of 0.4% on general background of the increasing of X-ray activity in the region. This fact influenced the change in the radiation-hygienic indexes of medical radiation exposure of the population of RT. According to №3-DOZ forms and radiation-hygienic passports of the

  17. Dose, exposure time, and resolution in Serial X-ray Crystallography

    Starodub, D; Hembree, G; Howells, M; Shapiro, D; Chapman, H N; Fromme, P; Schmidt, K; Weierstall, U; Doak, R B; Spence, J C H

    2007-01-01

    The resolution of X-ray diffraction microscopy is limited by the maximum dose that can be delivered prior to sample damage. In the proposed Serial Crystallography method, the damage problem is addressed by distributing the total dose over many identical hydrated macromolecules running continuously in a single-file train across a continuous X-ray beam, and resolution is then limited only by the available molecular and X-ray fluxes and molecular alignment. Orientation of the diffracting molecules is achieved by laser alignment. We evaluate the incident X-ray fluence (energy/area) required to obtain a given resolution from (1) an analytical model, giving the count rate at the maximum scattering angle for a model protein, (2) explicit simulation of diffraction patterns for a GroEL-GroES protein complex, and (3) the frequency cut off of the transfer function following iterative solution of the phase problem, and reconstruction of an electron density map in the projection approximation. These calculations include c...

  18. Microstructured polymer films by X-ray lithographic exposure and grafting

    Recently we reported on a new technique to generate micro- and nanostructured polymer materials by the combination of selective irradiation of polymer substrates with X-rays and subsequent grafting of a second polymer. Here we focus on the spatially defined grafting throughout the thickness of poly(ethylene-alt-tetrafluoroethylene) (ETFE) and poly (tetrafluoroethylene-co-hexafluoropropylene) (FEP) films using X-ray irradiation through a metal mask, followed by grafting with styrene. Calculations of the transmission of X-rays through the polymer as a function of the wavelength have revealed that energy deposition within the substrate material, which should control the density of created radicals, can be selected in a wide range. Depending on the used wavelength the radicals are created either near the surface or in the bulk of the sample. First experiments demonstrated spatially defined grafting through a 100 μm thick ETFE film and 25 μm thick FEP film. The achieved graft level depends on the irradiation dose as well as on the grafting parameters such as concentration, temperature and time. The precision of structure definition within the film depends on the properties of the X-ray source, the metal mask and the grafting process. The presented process allows controlled grafting through fluoropolymer films with micrometer resolution and local modification of the properties of the films, such as ion conductivity, diffusion of specific molecules or optical properties

  19. Microstructured polymer films by X-ray lithographic exposure and grafting

    Gürsel, Selmiye A.; Padeste, Celestino; Solak, Harun H.; Scherer, Günther G.

    2005-07-01

    Recently we reported on a new technique to generate micro- and nanostructured polymer materials by the combination of selective irradiation of polymer substrates with X-rays and subsequent grafting of a second polymer. Here we focus on the spatially defined grafting throughout the thickness of poly(ethylene-alt-tetrafluoroethylene) (ETFE) and poly (tetrafluoroethylene-co-hexafluoropropylene) (FEP) films using X-ray irradiation through a metal mask, followed by grafting with styrene. Calculations of the transmission of X-rays through the polymer as a function of the wavelength have revealed that energy deposition within the substrate material, which should control the density of created radicals, can be selected in a wide range. Depending on the used wavelength the radicals are created either near the surface or in the bulk of the sample. First experiments demonstrated spatially defined grafting through a 100 μm thick ETFE film and 25 μm thick FEP film. The achieved graft level depends on the irradiation dose as well as on the grafting parameters such as concentration, temperature and time. The precision of structure definition within the film depends on the properties of the X-ray source, the metal mask and the grafting process. The presented process allows controlled grafting through fluoropolymer films with micrometer resolution and local modification of the properties of the films, such as ion conductivity, diffusion of specific molecules or optical properties.

  20. Selenium Preferentially Accumulates in the Eye Lens Following Embryonic Exposure: A Confocal X-ray Fluorescence Imaging Study

    Choudhury, Sanjukta; Thomas, Jith; Sylvain, Nicole J.; Ponomarenko, Olena; Gordon, Robert A.; Heald, Steve M.; Janz, David M.; Krone, Patrick H.; Coulthard, Ian; George, Graham N.; Pickering, Ingrid J.

    2015-02-17

    Maternal transfer of elevated selenium (Se) to offspring is an important route of Se exposure for fish in the natural environment. However, there is a lack of information on the tissue specific spatial distribution and speciation of Se in the early developmental stages of fish, which provide important information about Se toxicokinetics. The effect of maternal transfer of Se was studied by feeding adult zebrafish a Se-elevated or a control diet followed by collection of larvae from both groups. Novel confocal synchrotron-based techniques were used to investigate Se within intact preserved larvae. Confocal X-ray fluorescence imaging was used to compare Se distributions within specific planes of an intact larva from each of the two groups. The elevated Se treatment showed substantially higher Se levels than the control; Se preferentially accumulated to highest levels in the eye lens, with lower levels in the retina, yolk and other tissues. Confocal X-ray absorption spectroscopy was used to determine that the speciation of Se within the eye lens of the intact larva was a selenomethionine-like species. Preferential accumulation of Se in the eye lens may suggest a direct cause-and-effect relationship between exposure to elevated Se and Se-induced ocular impairments reported previously. This study illustrates the effectiveness of confocal X-ray fluorescence methods for investigating trace element distribution and speciation in intact biological specimens

  1. Organ and tissue equivalent doses from abdominal x-ray examinations calculated with the MAX/EGS4 exposure model

    Full text: The incident air kerma (INAK), the entrance surface air kerma (ESAK), and the dose-area product (DAP) are considered relevant measurable quantities, suitable to be used for the evaluation of exposure to the patient in x-ray diagnosis. The recently developed MAX (Male Adult voXel) phantom connected to the EGS4 Monte Carlo code was used to calculate conversion coefficients between average equivalent dose to organs and tissues at risk and the measurable quantities INAK, ESAK, and DAP, respectively, for a variety of commonly performed x-ray examinations. This investigation presents conversion coefficients between organ and tissue equivalent dose and ESAK for abdominal x-ray examinations for the MAX phantom, which will be compared with corresponding results for mathematical MIRD5-type phantoms published by others. The comparison shows agreement and disagreement between the data for the two exposure models, which clearly reflect the anatomical differences with respect to shape and position of the organs at risk. (orig.)

  2. Development of a head simulator for exposure dose estimation on patients exposed by odontological X-rays

    In the obtaining a odontological radiography, the individual is exposed to te radiation and part of that radiation will be absorbed by his organism. The estimative of absorbed dose can be accomplished through calculations where are considered: the distance from the source to the individual, the energy of the emitted X-ray at the moment of the exposure and the bode region exposed; and as that option does not possess great precision, alternative forms are seek for the quantification such doses. This work proposes the construction of a head simulator to be used in the estimative of absorbed dose in patients, during the accomplishment of the odontological radiographic examinations. As a perspective of work, it is intended to use the phantom to help in the absorbed doses for obtainment of parameters in X-ray odontological devices, contributing of image obtainment with more quality and less radiation dose in the patient

  3. X-ray tubes

    An improved form of x-ray tube is described which consists of a rotatable anode disc and an electron beam source enclosed in an envelope. The beam of electrons strikes the edge of the anode disc at an acute angle, producing x-rays which are transmitted through a window in the envelope. To improve performance and life of the anode disc it is additionally reciprocated back and forth along its axis of rotation. Dimensions are specified. (U.K.)

  4. Exposure assessment of neonates in israel to x-ray radiation during hospitalization at neonatal intensive care unit

    Nowadays nearly 10% of all births in western countries are premature. In the last decade, there has been an increase of 45% in the number of neonates that were born in Israel. At the same time, the survival of neonates, especially those with very low birth weight, VLBW, (less than 1,500 gr), has increased dramatically. Diagnostic radiology plays an important role in the assessment and treatment of neonates requiring intensive care. During their prolonged and complex hospitalization, these infants are exposed to multiple radiographic examinations involving X-ray radiation. The extent of the examinations that the infant undergoes depends on its birth weight, gestational age and its medical problems, where most of the treatment effort is focused especially on VLBW neonates. Most of the diagnostic X-ray examinations taken during the hospitalization of neonates in the neonatal intensive care unit (NICU) consist of imaging of the respiratory and gastrointestinal systems, namely, the chest and abdomen. The imaging process is done using mobile X-ray units located at the NICUs. Due to their long hospitalization periods and complex medical condition, all neonates, and neonates with VLBW in particular, are exposed to a much higher level of diagnostic radiation, compared to normal newborns. The goal of this research was to assess the extent of the exposure of neonates in Israel to X-ray radiation during their hospitalization at the neonatal intensive care unit. Five NICUs, located at different geographical zones in Israel and treating 20% of all newborns in Israel every year, participated in this research. The research was conducted in three phases: Phase I: Collection of information on radiographic techniques and exposure parameters (e.g. kV, mAs, focus to skin distance (FSD), examination borders). 499 X-ray examinations (from 157 neonates) were evaluated for necessary and unnecessary exposure of the neonate's organs to X-ray radiation during these examinations. Phase II

  5. A real-time regional adaptive exposure method for saving dose-area product in x-ray fluoroscopy

    Purpose: Reduction of radiation dose in x-ray imaging has been recognized as a high priority in the medical community. Here the authors show that a regional adaptive exposure method can reduce dose-area product (DAP) in x-ray fluoroscopy. The authors' method is particularly geared toward providing dose savings for the pediatric population. Methods: The scanning beam digital x-ray system uses a large-area x-ray source with 8000 focal spots in combination with a small photon-counting detector. An imaging frame is obtained by acquiring and reconstructing up to 8000 detector images, each viewing only a small portion of the patient. Regional adaptive exposure was implemented by varying the exposure of the detector images depending on the local opacity of the object. A family of phantoms ranging in size from infant to obese adult was imaged in anteroposterior view with and without adaptive exposure. The DAP delivered to each phantom was measured in each case, and noise performance was compared by generating noise arrays to represent regional noise in the images. These noise arrays were generated by dividing the image into regions of about 6 mm2, calculating the relative noise in each region, and placing the relative noise value of each region in a one-dimensional array (noise array) sorted from highest to lowest. Dose-area product savings were calculated as the difference between the ratio of DAP with adaptive exposure to DAP without adaptive exposure. The authors modified this value by a correction factor that matches the noise arrays where relative noise is the highest to report a final dose-area product savings. Results: The average dose-area product saving across the phantom family was (42 ± 8)% with the highest dose-area product saving in the child-sized phantom (50%) and the lowest in the phantom mimicking an obese adult (23%). Conclusions: Phantom measurements indicate that a regional adaptive exposure method can produce large DAP savings without compromising the

  6. A real-time regional adaptive exposure method for saving dose-area product in x-ray fluoroscopy

    Burion, Steve; Funk, Tobias [Triple Ring Technologies, Inc., 39655 Eureka Drive, Newark, California 94560 (United States); Speidel, Michael A. [Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States)

    2013-05-15

    Purpose: Reduction of radiation dose in x-ray imaging has been recognized as a high priority in the medical community. Here the authors show that a regional adaptive exposure method can reduce dose-area product (DAP) in x-ray fluoroscopy. The authors' method is particularly geared toward providing dose savings for the pediatric population. Methods: The scanning beam digital x-ray system uses a large-area x-ray source with 8000 focal spots in combination with a small photon-counting detector. An imaging frame is obtained by acquiring and reconstructing up to 8000 detector images, each viewing only a small portion of the patient. Regional adaptive exposure was implemented by varying the exposure of the detector images depending on the local opacity of the object. A family of phantoms ranging in size from infant to obese adult was imaged in anteroposterior view with and without adaptive exposure. The DAP delivered to each phantom was measured in each case, and noise performance was compared by generating noise arrays to represent regional noise in the images. These noise arrays were generated by dividing the image into regions of about 6 mm{sup 2}, calculating the relative noise in each region, and placing the relative noise value of each region in a one-dimensional array (noise array) sorted from highest to lowest. Dose-area product savings were calculated as the difference between the ratio of DAP with adaptive exposure to DAP without adaptive exposure. The authors modified this value by a correction factor that matches the noise arrays where relative noise is the highest to report a final dose-area product savings. Results: The average dose-area product saving across the phantom family was (42 {+-} 8)% with the highest dose-area product saving in the child-sized phantom (50%) and the lowest in the phantom mimicking an obese adult (23%). Conclusions: Phantom measurements indicate that a regional adaptive exposure method can produce large DAP savings without

  7. Dose assessment for medical exposure from diagnostic X-rays using a human voxel model

    Korean voxel model, KORMAN, segmented from whole-body MR data of an adult male, was used to calculate organ equivalent doses and effective doses due to diagnostic X-ray examinations. Calculated doses were normalized to entrance air kerma and compared with those derived using a stylized mathematical model, MIRD5. General purposed Monte Carlo code, MCNPX 2.3 was used for simulation of X-ray procedure. Korean voxel model picked up 0.048 Sv/Gy of effective dose per unit air kerma from a single chest PA examination, and 0.277 Sv/Gy from abdomen AP examination. These calculated results are higher than those MIRD5. The difference of effective doses between Korean voxel model and MIRD5 was within 32%, which were caused by significant discrepancies of organ equivalent doses between the two models. As MIRD5 is representing reference man, whereas KORMAN is segmented from specific individual MR data, it is recognized that variation among individuals could be significant for dose assessment in X-ray examination. Substantial differences in calculated doses between voxel and mathematical models suggested that existing mathematical models should be revised. (author)

  8. Similarity in the acute cytotoxic response of mammalian cells to mercury (II) and x-rays: DNA damage and glutathione depletion

    Pronounced strand breakage of DNA analyzed elution techniques was produced in intact Chinese hamster ovary cells by 25 μM HgCl2 within 1 hr or 100 μM HgCl2 within 15 min. HgCl2-induced strand breakage was directly proportional to concentration up to 100 μM and to time within 1 hr. Levels of reduced glutathione decreased following HgCl2 in parallel with the induction of DNA strand breakage. Evidence is presented that this rapid and pronounced induction of DNA strand breaks and other cytotoxic responses following acute exposure to HgCl2 resembles the cellular effects of X-rays

  9. On the radiation exposure dose and health management history during 50 years of x-ray working

    My X-ray working history has become 50 years at the end of April, 1980. At this chance, the following data were summarized; the case numbers of X-ray photographs (517,132 cases), total amounts of radiation exposure dose (66.85 roentgen) and the results of blood test, which were experienced during past 50 years. The amounts of exposure dose during 35 years till 1965 were measured using my own method, which measured the film blackening as 30 milli-roentgen per week by certain standard method. After 1966 till 1980, the exposure dose were recorded using that of the film-badge service of Nippon Hoan Yohin Kyokai. The total amounts of exposure dose during 50 years were about 1/4 of D = 5 (N - 18). The results of blood test during last 27 years were found to be normal values. Then, it is happy to say that my body has been protected completely, from radiation hazard as a result of taking radiation protection and checking blood test always at my daily radiation works. The data of my own experiences during 50 years are summarized and reported in this paper. (author)

  10. ERX: a software for editing files containing X-ray spectra to be used in exposure computational models

    Cabral, Manuela O.M.; Vieira, Jose W.; Silva, Alysson G.; Leal Neto, Viriato [Instituto Federal de Educacao, Ciencia e Tecnologia de Pernambuco (IFPE), Recife, PE (Brazil); Oliveira, Alex C.H.; Lima, Fernando R.A., E-mail: falima@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2011-07-01

    Exposure Computational Models (ECMs) are utilities that simulate situations in which occurs irradiation in a given environment. An ECM is composed primarily by an anthropomorphic model (phantom), and a Monte Carlo code (MC). This paper presents a tutorial of the software Espectro de Raios-X (ERX). This software performs reading and numerical and graphical analysis of text files containing diagnostic X-ray spectra for use in algorithms of radioactive sources in the ECMs of a Grupo de Dosimetria Numerica. The ERX allows the user to select one among several X-ray spectrums in the energy range Diagnostic radiology X-Ray most commonly used in radiology clinics. In the current version of the ERX there are two types of input files: the contained in mspectra.dat file and the resulting of MC simulations in Geant4. The software allows the construction of charts of the Probability Density Function (PDF) and Cumulative Distribution Function (CDF) of a selected spectrum as well as the table with the values of these functions and the spectrum. In addition, the ERX allows the user to make comparative analysis between the PDF graphics of the two catalogs of spectra available, besides being can perform dosimetric evaluations with the selected spectrum. A software of this kind is an important computational tool for researchers in numerical dosimetry because of the diversity of Diagnostic radiology X-Ray machines, which implies in a mass of input data highly diverse. And because of this, the ERX provides independence to the group related to the data origin that is contained in the catalogs created, not being necessary to resort to others. (author)

  11. X-ray equipment for dental diagnostics with a dose-rate controller influencing the exposure voltage

    If a synoptic picture is taken of teeth or jaw the X-ray tube and the film carrier with the film and a radiation detector are moving around the patient's head. The detector signal is connected to the input of the actual value of the dose-rate controller containing a scanning and stop circuit with a storing time roughly corresponding to the exposure of three teeth. After the shot the actual value of the dose rate is adjusted to the desired value, thus a constant quality of the following pictures being achieved. (RW)

  12. Chromosome aberrations in somatic and germ cells following exposure to 300 R X-ray to rabbits

    A comparison is made of the chromosome aberrations yield in peripheral blood lymphocytes and spermatogonia of rabbits following exposure to 300 R X-rays. Cytogenetic analysis of lymphocytes immediately after irradiation revealed 28,0 per cent aberrant cells, including 0,17 dicentrics per cell. 120 days later less aberrations in primary spermatocytes at diakinesis - metaphasis I - 0,025 translocations per cell - were found. 60 days after irradiation the aberration rate in lymphocytes drops to the spontaneous level - 0,16 per cent aberrant cells - but analysis of karyotyped metaphases show anomalies which are unidentifiable after simple microscopic scoring. (A.B.)

  13. SU-E-I-52: Effect of Various X-Ray Beam Qualities On the Exposure Index

    Purpose: The exposure index (EI) proposed by the International Electrotechnical Commission (IEC) 62494-1 is expected to be utilized as a standard dose index by every manufacturer. The IEC recommended the usage of RQA5 for the EI. However, X-ray beam qualities, particularly in clinical practices, vary depending on the examination objects and exposure conditions, including usage of anti-scatter grids. We investigated the effects of the X-ray beam qualities other than RQA5 on the EI. Methods: The Xray beam qualities of RQA3, 5, 7, and 9 in IEC 61267 Ed. 1.0 were adopted in a computed radiography system. A uniform exposure without objects was performed to measure the exposure indicators (S values) and air kerma (K). The relational equations between the S values and K were derived for the determination of the EI values. The EI values for RQA3, 7, and 9 were compared to those for RQA5 at the fixed S values of 100, 200, 400, and 600. Finally, the half-value layers (HVLs) using four grids (ratio 6:1, 8:1, 10:1, and 12:1) for the RQA5 X-ray were compared to those with RQA3–9. Results: The EI values for RQA3, 7, and 9 were up to 35.3%, 11.8%, and 38.7% higher, respectively, than that for RQA5 at the S value of 600. The HVLs without grids and with various grids for RQA5 were 6.85 mm Al. and in the range of 6.94–7.29 mm Al. (ΔHVL: up to 0.44 mm Al.), respectively. This variation in the HVLs with grids was smaller than that observed for RQA3–9 (ΔHVL: 2.0–7.5 mm Al.). Conclusion: Although the usage of grids may not greatly affect the EI, the X-ray beam quality for the determination of the EI cannot be ignored in the clinical evaluation of the dose index

  14. Development of acute stage cerebral infarction detection method in X-rays CT image using morphological filter

    Cerebrovascular disease is currently the third cause of death in Japan. Recent westernization of the diet and an increase in geriatric diseases has now made cerebral infarction the focus of much research. Prehospital thrombolysis with alteplase (rt-PA) is reported to be effective for cerebral infarction that is defined as 'ischemic stroke, the treatment for which can be started within 3 hours after the development.' However, X-ray CT imaging visualizes acute-stage cerebral infarction as a low attenuation area, making it difficult to detect. This study presents a method to detect acute-stage cerebral infarction that uses a morphological filter in the algorithm. Using an image in which the cerebral parenchyma was extracted, and assuming that chronic-stage and acute-stage infarction sites were similar regions, the threshold and the pixel number were calculated based on the tendency of the CT values. In the binary format image, candidate regions were narrowed down by repeatedly applying an open-closing filter four times, while changing the structural element to 5, 10, 20, and 40. Since the infarction region after labeling tended to exceed 200 pixels, regions below 200 pixels were removed to detect the final candidate region for acute-stage cerebral infarction. (author)

  15. Europium- and lithium-doped yttrium oxide nanocrystals that provide a linear emissive response with X-ray radiation exposure.

    Stanton, Ian N; Belley, Matthew D; Nguyen, Giao; Rodrigues, Anna; Li, Yifan; Kirsch, David G; Yoshizumi, Terry T; Therien, Michael J

    2014-05-21

    Eu- and Li-doped yttrium oxide nanocrystals [Y2-xO3; Eux, Liy], in which Eu and Li dopant ion concentrations were systematically varied, were developed and characterized (TEM, XRD, Raman spectroscopic, UV-excited lifetime, and ICP-AES data) in order to define the most emissive compositions under specific X-ray excitation conditions. These optimized [Y2-xO3; Eux, Liy] compositions display scintillation responses that: (i) correlate linearly with incident radiation exposure at X-ray energies spanning from 40-220 kVp, and (ii) manifest no evidence of scintillation intensity saturation at the highest evaluated radiation exposures [up to 4 Roentgen per second]. For the most emissive nanoscale scintillator composition, [Y1.9O3; Eu0.1, Li0.16], excitation energies of 40, 120, and 220 kVp were chosen to probe the dependence of the integrated emission intensity upon X-ray exposure-rate in energy regimes having different mass-attenuation coefficients and where either the photoelectric or the Compton effect governs the scintillation mechanism. These experiments demonstrate for the first time for that for comparable radiation exposures, when the scintillation mechanism is governed by the photoelectric effect and a comparably larger mass-attenuation coefficient (120 kVp excitation), greater integrated emission intensities are recorded relative to excitation energies where the Compton effect regulates scintillation (220 kVp) in nanoscale [Y2-xO3; Eux] crystals. Nanoscale [Y1.9O3; Eu0.1, Li0.16] (70 ± 20 nm) was further exploited as a detector material in a prototype fiber-optic radiation sensor. The scintillation intensity from the [Y1.9O3; Eu0.1, Li0.16]-modified, 400 μm sized optical fiber tip, recorded using a CCD-photodetector and integrated over the 605-617 nm wavelength domain, was correlated with radiation exposure using a Precision XRAD 225Cx small-animal image guided radiation therapy (IGRT) system. For both 80 and 225 kVp energies, this radiotransparent device

  16. Studies on the radiation exposure and protection at the X-ray radiography in the medical care at home

    Since there are scarce studies on the exposure and protection at the radiography in the medical care at home, authors performed such studies as comparison of doses from self-rectifying and inverter tubes, exposure and protection to patients and nursing persons and actual measurement (October, 1997) at home in Tohno city, Iwate prefecture, of scattering radiation dose at radiography. Apparatuses used were: Portable X-ray equipments; self-rectifying types (Toshiba TR-20 and Medisonacoma PX 30N) and an inverter type (Medisonacoma PX-15HF), Kyoto Kagaku WAC water phantom, X-ray analyzer Model 200 of Kasei Optonics, and Dosimeters (Victoreen Radocon ionization dosimeter and Aloka ICS-301 ionization chamber survey meters). Radiation qualities, surface doses and scattering doses of the equipments under various conditions were compared by the half value layer and effective energy measured with the analyzer. Actual measurement of scattering dose was done at home for 4 patients at chest radiography. Annual dose in monthly ordinary radiography at home, when the distance was >200 cm far from the flux center, was found about 1/100 of 1 mSv (the annual public dose limit), thus securing the safety of nurses. (K.H.)

  17. Angularly resolved X-ray photoelectron spectroscopy investigation of PTFE after prolonged space exposure

    Dalins, I.; Karimi, M.

    1992-01-01

    Monochromatized angularly resolved X-ray photoelectron spectroscopy (ARXPS) was used to study PTFE (Teflon) that had been exposed to an earth orbital environment for approximately six years. The primary interest of the research is on a very reactive component of this environment (atomic oxygen) which, because of the typical orbital velocities of a spacecraft, impinge on exposed surfaces with 5 eV energy. This presentation deals with the method of analysis, the findings as they pertain to a rather complex carbon, oxygen, and fluorine XPS peak analysis, and the character of the valence bands. An improved bias referencing method, based on ARXPS, is also demonstrated for evaluating specimen charging effects. It was found that the polymer molecule tends to resist the atomic oxygen attack by reorienting itself, so that the most electronegative CF3 groups are facing the incoming hyperthermal oxygen atoms. The implications of these findings to ground-based laboratory studies are discussed.

  18. Soft X-Ray Exposure Testing of FEP Teflon for the Hubble Space Telescope

    deGroh, Kim K.

    1998-01-01

    The FEP Teflon (DuPont) multilayer insulation (MLI) thermal-control blanket material on the Hubble Space Telescope is degrading in the space environment. During the first Hubble servicing mission in 1993, after 3.6 years in low Earth orbit, aluminized and silvered FEP Teflon MLI thermal-control blanket materials were retrieved. These materials have been jointly analyzed by the NASA Lewis Research Center and the NASA Goddard Space Flight Center for degradation induced in the space environment (ref. 1). Solar-facing blanket materials were found to be embrittled with through-the-thickness cracking in the 5-mil FEP. During the second Hubble servicing mission in 1997, astronauts noticed that several blankets had large areas with tears. The torn FEP was curled up in some areas, exposing the underlying materials to the space environment. This tearing problem, and the associated curling up of torn areas, could lead to over-heating of the telescope and to particulate contamination. A Hubble Space Telescope MLI Failure Review Board was assembled by Goddard to investigate and identify the degradation mechanism of the FEP, to identify and characterize replacement materials, and to estimate the extent of damage at the time of the third servicing mission in 1999. A small piece of FEP retrieved during the second servicing mission is being evaluated by this failure review board along with materials from the first servicing mission. Since the first servicing mission, and as part of the failure review board, Lewis has been exposing FEP to soft x-rays to help determine the damage mechanisms of FEP in the space environment. Soft x-rays, which can penetrate into the bulk of FEP, are generated during solar flares and appear to be contributing to the degradation of the Hubble MLI.

  19. X-ray signs of traumas of the cervical region of the spinal cord in the acute period

    The results are analyzed of an X-ray examination of 208 patients with traumas of the cervical region of the spinal column and spinal cord in the acute period of trauma. The authors proposed a scheme that included telespondylography in standard and oblique projections, flebospondylography, discography and pneumomyelography in the Schantz collar with a patient lying on the back. Four types of the spinal cord traumas were diagnosed: compression with osseous elements (76.92%), with sharp discs and strained epidural hematomas (3.85%), isolated contusion of the spinal cord (10.1%) and disorder of the spinal circulation (9.13%). Special emphasis was laid on clinicospondylographic correlations, a critical distance, congenital narrowing of the vertebral canal. The concept of traumatic decompression of the spinal cord was stressed. Symptoms of its contusion and trauma of the spinal circulation were indicated

  20. X-ray signs of traumas of the cervical region of the spinal cord in the acute period

    Brodskaya, Z.L. (Inst. Usovershenstvovaniya Vrachej, Novokuznetsk (USSR))

    The results are analyzed of an X-ray examination of 208 patients with traumas of the cervical region of the spinal column and spinal cord in the acute period of trauma. The authors proposed a scheme that included telespondylography in standard and oblique projections, flebospondylography, discography and pneumomyelography in the Schantz collar with a patient lying on the back. Four types of the spinal cord traumas were diagnosed: compression with osseous elements (76.92%), with sharp discs and strained epidural hematomas (3.85%), isolated contusion of the spinal cord (10.1%) and disorder of the spinal circulation (9.13%). Special emphasis was laid on clinicospondylographic correlations, a critical distance, congenital narrowing of the vertebral canal. The concept of traumatic decompression of the spinal cord was stressed. Symptoms of its contusion and trauma of the spinal circulation were indicated.

  1. Pulmonary complications of induction therapy for acute myeloid leukemia in adults. Findings of chest X-rays and computed tomography

    To exclude pulmonary complications, 359 chest radiographs and 50 computed tomographs of the lung were performed in 95 patients suffering from acute myeloid leukemia. The radiological findings were registered, described and correlated with clinical findings in the present study on 2395 days of observation. Results: In summary, 52 patients showed alterations of the lung. Pulmonary hyperhydration was seen in 21 cases, bacterial pneumonia was found in 18 cases, invasive pulmonary aspergillosis was documented in 14 cases, and 5 cases of severe haemorrhage were seen. An unexplained pulmonary edema in 13 patients with interstitial and alveolar infiltrates is considered to be a complication of treatment with cytosine-arabinoside. Conclusion: The results demonstrate that chest X-ray and computed tomography have a high impact in detection and treatment of pulmonary complications following intensive chemotherapy. We may expect the development of diffuse opacity following administration of cytosine-arabinoside in medium-sized doses. (orig.)

  2. Acute response of pig skin to irradiation with 12C-ions or 200 kV X-rays

    The acute response of pig skin to treatment with high energy carbon ions (plateau region) at the Gesellschaft fuer Schwerionenforschung (GSI, Darmstadt, Germany) was compared to changes after 200 kV X-irradiation. Carbon doses isoeffective to the X-ray doses were computed with a recently established model for calculation of the biological effect of heavy ions (1, 2). Clinical changes and physiological symptoms (blood flow, erythema, transepidermal water loss, skin hydration) were scored. The parameters analyzed were maximum and mean values of each symptom during days 24 to 70 post irradiation, and the quantal endpoints for the establishment of dose-effect curves were the median values of these. With exception of the maximum change in the red blood cell concentration (p12C-ions (plateau region) and may at least for epidermis be applied to treatment planning. (orig.)

  3. Chest X-ray findings in the acute phase of Kawasaki disease

    We reviewed the chest X-ray (CXR) findings and clinical courses of 129 patients with Kawasaki disease and found abnormal CXR findings in 14.7% of the patients. Reticulogranular pattern was the most frequent abnormality (89.5%), while peribronchial cuffing (21.1%), pleural effusion (15.8%), atelectasis (10.5%) and air trapping (5.3%) were also seen. In each of these patients, CXR abnormalities appeared within 10 days after the onset of illness. In the group with abnormal CXR findings, a statistically significant increase was noted in duration of fever, incidence of adventitious sounds, serum CPR levels and incidence of coronary arterial lesions and pericardial effusion, as compared with the group having normal CXR findings. The pathological basis of these CXR changes is not clear, since no biopsy or autopsy specimen was obtained from these patients. Since none of these patients showed definite heart failure, it is difficult to consider that abnormal CXR findings were due to heart failure. On the other hand, physical signs and previous pathological reports suggested that the causes of abnormal CXR findings were lower respiratory tract inflammation and/or pulmonary arteritis. (orig.)

  4. Marked depression of time interval between fertilization period and hatching period following exposure to low-dose X-rays in zebrafish

    In recent years there has been growing concern over the stimulating effects of very low-dose X -rays. Our laboratory had observed that zebrafish irradiated with low-dose X-rays tended to emerge earlier than sham controls. This observation led us to quantitatively examine the effects of low-dose X irradiation on a series of stages of development in the zebrafish. The embryos were fertilized simultaneously in vitro and incubated at an optimal temperature without crowding. Following exposure of the cleavage period (1.5 h after fertilization) to 0.025-Gy X-rays, the duration to hatching was slightly shorter than that of the sham controls. This tendency was increased when the X-ray exposure occurred during the blastula period (3.5 h). In these embryos, the duration to hatching decreased significantly by an average of 6 h sooner than for sham controls. No differences in duration to hatching were seen when irradiation was given during either the zygote period (45 min) or the segmentation period (12 h). On the contrary, upon exposure to 0.5-Gy X-rays during the blastula period, the duration to hatching increased significantly relative to that of sham controls. These results suggest that the radiation-induced early hatching effect is observed for low doses of X-rays

  5. Study of the contribution of X-ray and gamma photons to the measured exposure dose

    The aim of this work was to study the contribution of X-rays and gamma radiation to the measured dose in the city of Antananarivo. The annual indoor absorbed dose was studied as well. Measurements were carried out in twelve sites, namely public schools and churches. The mean dose rate lies between (0.34±0.03)μSv/h and (0.38±0.04)μSv/h for most of the sites. Two of them showed values between (0.40±0.04)μSv/h and (0.30±0.03)μSv/h. Mean indoor dose rate is of (0.36±0.04)μSv/h and the annual absorbed dose is (3.16±0.32)mSv/person. Indoor measurements showed mean integral values ranging from (277.22±0,22)cps to (733.66±0,37)cps. The lowest mean count rate is (277.22±0,22)cps, measured in the AMARO site, whereas the highest are (733,66±0,37)cps, (697,81±0,36)cps and (689,32±0,36)cps measured in ALO0 , AKELY, and MASINA respectively.

  6. Acute shoulder injury with a normal x-ray: a simple algorithm of patient assessment to guide the need for further imaging

    O’Rourke, S

    2012-09-20

    Purpose: Patients presenting to their General Practitioner or to the Emergency Department following an acute shoulder injury but a normal x-ray may have a significant underlying injury to the Rotator Cuff. Imaging (whether by ultrasound or MRI) is often indicated but available clinical evidence has yet to establish what group of patients benefit most from early imaging.\\r\

  7. Radio-adaptive Response: An Implication for the Biological Consequences of Low Dose-rate Exposure to X-Ray

    Radiation induced adaptive response is described as the reduced damaging effect of a challenging radiation dose when induced by a previous low priming dose. To verify the radio-adaptive response that can be induced by occupationally (in vivo) received chronic low dose of X-ray, chromosomal aberration (CA) analysis, micronucleus test (MN), interleukin-1β (IL-1β) and nitric oxide (NO) concentrations were investigated for both the occupationally exposed and control groups before and after exposure to 2 Gy γ-rays as a challenge dose. The results showed that an elevated frequency of CA, MN and nucleoplasmic bridge (NPB) was recorded in radiation workers (exposed group) compared to control group. However, after 2Gy in vitro irradiation of lymphocytes of exposed and control groups, the exposed group was found to be lower than that of control group. On the other hand, IL-1β and NO concentrations in plasma were elevated in exposed group more than in control group. While, after 2Gy irradiation for both groups, there are higher increment in the concentrations of IL-1β and NO in exposed group than the increment difference observed for control group after in vitro irradiation as compared to the same group before irradiation. The present results suggested the existence of an in vivo cytogenetic adaptive response in individuals occupationally exposed to low dose of X-ray. In addition, the results showed that NO radicals and IL-1β have a role in the induction of radio-resistance due to in vivo exposure that may intermediate this radiation.

  8. Enhancement of mitogen response of rat lymphocytes by whole body exposure to low dose x-ray

    The hypothesis of radiation hormesis was proposed. In order to elucidate the hormetic effect on immune system, the mitogen response of rat lymphocytes after the exposure to low dose X-ray was studied. Male rats were subjected to the whole body exposure from 0.01 to 2 Gy. The lymphocytes from spleens, thymuses and bone marrows were prepared at the prescribed time after the irradiation, thereafter, they were incubated at 37 degC for 48 hours in the presence of mitogens. The cells were pulsed with [H-3]-thymidine in the final 4 hours of culture, and the cell growth was evaluated by its intake into the cells. The results obtained were as follows. The in vitro concanavalin A (Con A) response of the spleen cells prepared 4 hours after the irradiation increased by the exposure to 0.05 Gy, whereas the response of thymus and bone marrow cells did not change. These spleen cells showed the increase of relative Con A response by 240 %, while their mitogen response to phytohemagglutinin and lipopolysaccharide was only 150 %. This enhancement of mitogen response of spleen cells was observed within a few hours after the irradiation, so it is a temporary effect. Low dose exposure may induce a hormesis-like effect. (K.I.)

  9. Selective brain responses to acute and chronic low-dose X-ray irradiation in males and females

    Radiation exposure is known to have profound effects on the brain, leading to precursor cell dysfunction and debilitating cognitive declines [Nat. Med. 8 (2002) 955]. Although a plethora of data exist on the effects of high radiation doses, the effects of low-dose irradiation, such as ones received during repetitive diagnostic and therapeutic exposures, are still under-investigated [Am. J. Otolaryngol. 23 (2002) 215; Proc. Natl. Acad. Sci. USA 97 (2000) 889; Curr. Opin. Neurol. 16 (2003) 129]. Furthermore, most studies of the biological effects of ionizing radiation have been performed using a single acute dose, while clinically and environmentally relevant exposures occur predominantly under chronic/repetitive conditions. Here, we have used a mouse model to compare the effects of chronic/repetitive and acute low-dose radiation (LDR) exposure (0.5 Gy) to ionizing radiation on the brain in vivo. We examined the LDR effects on p42/44 MAPK (ERK1/ERK2), CaMKII, and AKT signaling-the interconnected pathways that have been previously shown to be crucial for neuronal survival upon irradiation. We report perturbations in ERK1/2, AKT, and CREB upon acute and chronic/repetitive low-dose exposure in the hippocampus and frontal cortex of mice. These studies were paralleled by the analysis of radiation effects on neurogenesis and cellular proliferation. Repetitive exposure had a much more pronounced effect on cellular signaling and neurogenesis than acute exposure. These results suggest that studies of single acute exposures might be limited in terms of their predictive value. We also present the first evidence of sex differences in radiation-induced signaling in the hippocampus and frontal cortex. We show the role of estrogens in brain radiation responses and discuss the implications of the observed changes

  10. DEVELOPMENT OF DIAGNOSTIC REFERENCE LEVELS (DRL OF PATIENTS X-RAY EXPOSURE IN DIAGNOSTIC RADIOLOGY

    A. V. Vodovatov

    2013-01-01

    Full Text Available We introduce a system of Diagnostic Reference Levels (DRLs for patients medical exposure for national health care practice implementation. DRLs are an effective way of the patient radiation protection through the optimization of the medical exposure. The paper discusses and compares different methods of determining the DRLs based on measured and/or calculated quantities of patient’s dose: dose area product (DAP, entrance surface dose (ESD and an effective dose. Distributions of different dose quantities in different Saint-Petersburg clinics are shown on the example of chest PA examinations. The results are compared with the data from other sources. Regional DRLs for Saint-Petersburg are proposed.

  11. Analysis of Flow Cytometry DNA Damage Response Protein Activation Kinetics Following X-rays and High Energy Iron Nuclei Exposure

    Universities Space Research Association; Chappell, Lori J.; Whalen, Mary K.; Gurai, Sheena; Ponomarev, Artem; Cucinotta, Francis A.; Pluth, Janice M.

    2010-12-15

    We developed a mathematical method to analyze flow cytometry data to describe the kinetics of {gamma}H2AX and pATF2 phosphorylations ensuing various qualities of low dose radiation in normal human fibroblast cells. Previously reported flow cytometry kinetic results for these DSB repair phospho-proteins revealed that distributions of intensity were highly skewed, severely limiting the detection of differences in the very low dose range. Distributional analysis reveals significant differences between control and low dose samples when distributions are compared using the Kolmogorov-Smirnov test. Radiation quality differences are found in the distribution shapes and when a nonlinear model is used to relate dose and time to the decay of the mean ratio of phosphoprotein intensities of irradiated samples to controls. We analyzed cell cycle phase and radiation quality dependent characteristic repair times and residual phospho-protein levels with these methods. Characteristic repair times for {gamma}H2AX were higher following Fe nuclei as compared to X-rays in G1 cells (4.5 {+-} 0.46 h vs 3.26 {+-} 0.76 h, respectively), and in S/G2 cells (5.51 {+-} 2.94 h vs 2.87 {+-} 0.45 h, respectively). The RBE in G1 cells for Fe nuclei relative to X-rays for {gamma}H2AX was 2.05 {+-} 0.61 and 5.02 {+-} 3.47, at 2 h and 24-h postirradiation, respectively. For pATF2, a saturation effect is observed with reduced expression at high doses, especially for Fe nuclei, with much slower characteristic repair times (>7 h) compared to X-rays. RBEs for pATF2 were 0.66 {+-} 0.13 and 1.66 {+-} 0.46 at 2 h and 24 h, respectively. Significant differences in {gamma}H2AX and pATF2 levels comparing irradiated samples to control were noted even at the lowest dose analyzed (0.05 Gy) using these methods of analysis. These results reveal that mathematical models can be applied to flow cytometry data to uncover important and subtle differences following exposure to various qualities of low dose radiation.

  12. Manifestations Analysis About the Acute Pyogenic Osteomyelitis By X-ray%急性化脓性骨髓炎X线表现分析

    刘文辉

    2015-01-01

    ObjectiveTo study the X-ray imaging manifestations of the patients with acute pyogenic osteomyelitis.MethodsSelected 20 cases X-ray datum of the patients with acute pyogenic osteomyelitis to analyse from January 2012 to June 2014.Results The X-ray showed that there were 6 cases got intervertebral space stenosis, 2 cases got vertebral endplate failure and 12 cases got the destruction of vertebral bodies.Conclusion The skeletal positive X-ray signs of acute pyogenic osteomyelitis is displayed in the 10 days before onset, but the changes of the soft tissue will appear after 2 to 3 days when it onset. The X-ray examination with the advantages of convenient, simple, cheap, good effect and so on, and it still as the preferred method for diagnosis of acute suppurative osteomyelitis.%目的:探讨急性化脓性骨髓炎患者X线影像表现。方法选取2012年1月~2014年6月收治的急性化脓性骨髓炎患者20例X线检查资料进行分析。结果X线表现为椎间隙狭窄6例,椎体终板破坏2例,椎体破坏12例。结论急性化脓性骨髓炎的骨骼阳性X线征象需在发病10天后才能显示,但软组织的改变在发病后2~3天即可出现。X线检查以其方便、简单、便宜、效果良好等优点,仍作为诊断急性化脓性骨髓炎的首选方法。

  13. Patient exposure reduction in x-ray CT with yttrium filters

    Custom-designed yttrium filters were installed on three General Electric CT/T 98000 CT scanners. Measurements were made before and after installation of the yttrium filters. The phantom test evaluations included: radiation exposure, high contrast spatial resolution, low contrast detectability, and CT number linearity/calibration. The reduction in exposure obtained for lucite head and body phantoms ranged from 22% to 27% on the surface and from 13% to 23% at the phantom center. The conclusion drawn is that no detrimental effect on image quality was observed through comparative analysis of the image parameters evaluated, nor were any differences in the quality of the pre- post-filter clinical images reported by the radiologists

  14. Parental exposure to low-dose X-rays in Drosophila melanogaster induces early emergence offspring, which can be modulated by transplantation of polar cytoplasm

    In recent years there has been growing concern over the biological effects of low-dose X-rays, but few studies have addressed this issue. Our laboratory had observed files (Drosophila melanogaster) irradiated with low dose X-rays tend to emerge earlier than normal flies. This observation led us to quantitatively examine the effects of low dose X-irradiation on development in the fly Following exposure of prepupal (day 5) flies to 0.5 Gy X-rays, the time to emergence was slightly shorter than in the sham controls. This tendency was increased when the X-ray exposure came during the pupal stage (day 7). In these flies, the time to eclosion decreased significantly, by an average of thirty hours sooner than sham controls. Exposure of pre pupa to 0.5 Gy results in marked changes in the puffing patterns of salivary gland chromosomes. A 0.5 Gy exposure induces puffing at 75B specific loci; this pattern of induced puffs shows little developmental specificity. A further experiment examined whether such radiation effects could be observed in the unexposed F1 generation of exposed individuals Greater radiation effects on early Fi emergence were seen when the time between exposure and mating was 3 days, indicating an effect on early spermatid development. Early F1 emergence was also observed after exposure of female flies to X-rays during late previtellogeny. furthermore, rapid emergence could be induced in the F1 embryos of unexposed parents by transferring the polar cytoplasm (precursor cells of the germ cell line) from F1 embryos of exposed flies. furthermore pumilio mutant arrested the assembly of polar cytoplasm did not induce the early emergency even after 0.5 Gy exposure. These results show that radiation-induced effects can be transmitted to the next generation through the germ cell line. (Author)

  15. Dose assessment and radioprotective medical evaluation of prenatal radiation exposures to diagnostic X-rays

    The 2nd to 15th weeks after conception are assessed to be the critical time period for the induction of teratogenic radiation damage. In the GDR, women having incurred fetal doses in excess of 100 mGy are recommended to interrupt pregnancy. Of 275 patients advised in the National Board for Atomic Safety and Radiation Protection between 1978 and 1988, approximately 90% were found to have received fetal doses below 20 mGy. Only 4 women had been exposed to doses above 100 mGy. Exposure data were given in the form of tables, and discussed. (author)

  16. Changes of gene expression in developing mouse brain after exposures to x-rays, in comparison with exposures to accelerated heavy ion particles

    Yaoi, Takeshi; Fushiki, Shinji [Kyoto Prefectural Univ. of Medicine, Dept. of Pathology and Applied Neurobiology, Kyoto (Japan); Nojima, Kumie [National Institute of Radiological Sciences, International Space Radiation Lab., Anagawa, Chiba (Japan)

    2003-07-01

    Prenatal exposure to ionizing radiation of low doses in rodents impedes neuronal migration during the period of cortical histogenesis, and results in disorganized cortical architecture in mature brain. On the contrary, exposure to heavy ion beams during fetal period mainly affects cell survival, viz., induction of apoptosis. However, the molecular mechanisms underlying to produce such difference in the effects between exposure to heavy particles and exposure to X-rays remain unknown. We have attempted to elucidate whether the changes of gene expression after exposure to heavy ions differ from those after X-irradiation in fetal brains. We thus applied two molecular biological techniques, i.e., the Restriction Landmark cDNA Scanning (RLCS) method and the suppression subtractive PCR method. Approximately 13,000 cDNA species were scanned and it turned out that more than twenty genes among the genes scanned were differentially expressed between X-irradiated embryos and non-irradiated ones. One of the genes showing up-regulation is Rab6A that is known to be associated with vesicle transport from trans-Golgi network. In addition, expression of some genes encoding RAB6A-interacting proteins was up-regulated. When expression of these genes was compared between animals after heavy-ion irradiation and those after X-irradiation, the changing pattern was different. Taking our previous observation that prenatal exposure to carbon particles induces apoptotic cell death in developing cerebral cortex into consideration, the difference in gene expression herein reported may contribute to better understand the difference in effects between exposures to heavy-ion particles and to X-rays. In conclusion, we identified Rab6A and its interacting proteins as candidates for the migration-associated genes, whose expression in fetal brain is up-regulated by carbon beam irradiation. (author)

  17. Hospital and clinic survey estimates of medical X-ray exposure in Hiroshima and Nagasaki, 2

    The technical factors used during radiological examinations performed in Hiroshima and Nagasaki medical institutions were analyzed. The most frequently performed examination was chest radiography, followed by upper GI series. More than half the radiographic exposures were from upper GI series due to the many spot films made during fluoroscopy. Comparison of the present survey results with those of a previous one showed that relatively high kVp, low mAs and mA, and smaller field sizes are now more widely used. Though there have been decreased in fluoroscopy times and tube currents over the past 10 years, the numbers of spot films used have increased. Based on these technical factors, tables of organ doses from fluoroscopic examinations were compiled. (author)

  18. Effects of one 150R x-ray exposure on DMBA-DNA adduct formation in Syrian hamster cheek pouch epithelium in vivo

    The authors' prior studies showed enhancement of DMBA carcinogenesis in hamster buccal pouch epithelium by repeated 20R head and neck x-ray exposures. Possible mechanisms included radiation-induced increases in covalent binding of DMBA to epithelial cell DNA. This pilot study assessed, at one time period, the effect of a single modest x-ray exposure on in vivo DMBA-DNA adduct formation in the cheek pouch. Hamsters received one 0.05ml topical application of 5.0μg 3H-DMBA (900μCi) in DMSO to the right pouch. Two hours later, 1/2 of the hamsters received a single 150R head and neck x-ray exposure. 24 hours after DMBA treatments, pouches were exercised and epithelium was isolated. Epithelial DNA was extracted and purified using homogenization, phenol-chloroform-isoamyl alcohol extraction, and spermine precipitation. DMBA-DNA adducts were calculated via scintillation spectrometry of radioactivity and fluorometry of DNA, and were expressed as μg DMBA bound / mg DNA. There was no significant difference between irradiated and non-irradiated groups in DMBA bound. This may reflect a true lack of radiation effect on DMBA binding, a temporal displacement of increased binding not detectable at 24 hours, or too small a binding increase from one x-ray exposure to detect. Ongoing studies are addressing these possibilities

  19. Study of the separate exposure method for bootstrap sensitometry on X-ray cine film

    We developed a new method for bootstrap sensitometry that obtained the characteristic curve from a wide range, with a smaller number of aluminum steps than the conventional bootstrap method. In this method, the density-density curve was obtained from standard and multiplied exposures to the aluminum step wedge and used for bootstrap manipulation. The curve was acquired from two regions separated and added together, e.g., lower and higher photographic density regions. In this study, we evaluated the usefulness of a new cinefluorography method in comparison with N.D. filter sensitometry. The shape of the characteristic curve and the gradient curve obtained with the new method were highly similar to that obtained with N.D. filter sensitometry. Also, the average gradient obtained with the new bootstrap sensitometry method was not significantly different from that obtained by the N.D. filter method. The study revealed that the reliability of the characteristic curve was improved by increasing the measured value used to calculate the density-density curve. This new method was useful for obtaining a characteristic curve with a sufficient density range, and the results suggested that this new method could be applied to specific systems to which the conventional bootstrap method is not applicable. (author)

  20. Fabrication of thin film x-ray sensor using particle-in-binder method for automatic exposure control in digital radiography

    An automatic exposure control (AEC) detector is a control device that ensures consistent x-ray image quality and limits patient exposure in digital radiography. Among several kinds of AEC detectors, solid-state sensors offer several advantages such as geometric efficiency due to small thickness, high sensitivity, fast reaction time, and excellent stability. Commercially, the use of single-crystal silicon sensors for AEC detector has grown over time, but is still severely limited by large-area production techniques and mechanically fragile properties. Therefore, our study focused on developing a method of fabricating solid-state sensors that do not suffer from these limitations. The particle-in-binder method was used to fabricate silicon dioxide-based photoconductor films. Because silicon dioxide has a low atomic number and a low work function, it is a suitable material for generating sufficient electron-hole pairs by incident x-rays as well as not negatively affect the image detector of the digital radiography. To verify the feasibility of the silicon dioxide film as an AEC detector, electrical properties such as x-ray transmission and x-ray linearity were measured and compared with those of a commercialized silicon film. Over 90% x-ray transmission was achieved using a 500 μ m silicon dioxide film, which is suitable for an AEC detector. Also, an error below 3% was obtained from both x-ray current and voltage linearity tests. The results of bending tests demonstrated the properties of the silicon dioxide film to be more mechanically strong and stable compared with the commercialized silicon film. These properties were a result of the use of binder materials, which resulted in the flexibility of the film

  1. Estimates of Average Glandular Dose with Auto-modes of X-ray Exposures in Digital Breast Tomosynthesis

    Izdihar Kamal

    2015-05-01

    Full Text Available Objectives: The aim of this research was to examine the average glandular dose (AGD of radiation among different breast compositions of glandular and adipose tissue with auto-modes of exposure factor selection in digital breast tomosynthesis. Methods: This experimental study was carried out in the National Cancer Society, Kuala Lumpur, Malaysia, between February 2012 and February 2013 using a tomosynthesis digital mammography X-ray machine. The entrance surface air kerma and the half-value layer were determined using a 100H thermoluminescent dosimeter on 50% glandular and 50% adipose tissue (50/50 and 20% glandular and 80% adipose tissue (20/80 commercially available breast phantoms (Computerized Imaging Reference Systems, Inc., Norfolk, Virginia, USA with auto-time, auto-filter and auto-kilovolt modes. Results: The lowest AGD for the 20/80 phantom with auto-time was 2.28 milliGray (mGy for two dimension (2D and 2.48 mGy for three dimensional (3D images. The lowest AGD for the 50/50 phantom with auto-time was 0.97 mGy for 2D and 1.0 mGy for 3D. Conclusion: The AGD values for both phantoms were lower against a high kilovolt peak and the use of auto-filter mode was more practical for quick acquisition while limiting the probability of operator error.

  2. Cancer incidence rate after diagnostic X-ray exposure in 1976-2003 among patients of a university children's hospital

    Purpose: Although the carcinogenic effect of ionizing radiation is well known, knowledge gaps persist on the health effects of low-dose radiation, especially in children. The cancer incidence rate in a cohort of 92,957 children diagnosed using X-rays in the years 1976-2003 in the radiology department of a large university clinic was studied. Materials and Methods: Individual radiation doses per examination were reconstructed using an algorithm taking into account the dose area product and other exposure parameters together with conversion factors computed specifically for the equipment and protocols used in the radiology department. Incident cancer cases in the period 1980-2006 were identified via record linkage to the German Childhood Cancer Registry using pseudonymized data. Results: A total of 87 cancers occurred in the cohort between 1980 and 2006: 33 leukemia, 13 lymphoma, 10 brain tumors, and 31 other tumors. The standardized incidence ratio (SIR) for all cancers was 0.99 (95 % CI: 0.79 1.22). A dose-response relationship was not observed for all cancers, leukemia and lymphoma or solid tumors. The cancer risks for boys and girls did not differ. Conclusion: No increase in the cancer incidence risk in relation to very low doses of diagnostic ionizing radiation was observed in this study. However, the results are compatible with a broad range of risk estimates. (orig.)

  3. PRELIMINARY RESULTS IN SYNCHROTRON X-RAY DIFFRACTION MEASUREMENTS OF RUBBER COMPOSITES STRUCTURE BEFORE AND AFTER EXPOSURE TO HYDROGEN

    Francesca Cosmi

    2011-05-01

    Full Text Available In future years, fuel cells are expected to represent a promising technology as a source of heat and electricity in buildings and of electrical power for vehicles, since fossil fuels are exhausting and significantly degrade air quality. It is well known that, when exposed to a hydrogen environment, hydrogen embrittlerment may affect materials such as iron and steel. But these are not the only materials that are used for hydrogen equipment. In particular, the rubber materials used for O–rings that seal high pressure hydrogen gas equipment show problems of internal fracture, called blister fracture, when the gas is rapidly decompressed. As many different kinds of fillers can be used, in this work we started to investigate the influence of the type of filler on the rubber composites structure, by means of X-ray diffraction measurements performed at the Elettra synchrotron radiation facility in Trieste. In this preliminary study, three kinds of samples were analyzed before and after exposure to hydrogen: Sulphur vulcanized EPDM, Peroxide vulcanized EPDM and Sulphur vulcanized NBR. While Peroxide vulcanized samples did not show significant differences in the diffraction pattern, changes could be detected in the cristalline form of Sulfure vulcanized rubber.

  4. Exposure values in routine and additional X-ray methods of exploration of the facial-maxillary area

    Thirty types of measurements on skeletalized paraffin modelled skulls were attempted in an X-ray study in classical projections on ''TUR 1000'' and ''Hofmann-SR-700D'' apparatuses, using standard dosimeter VA-I-18. Standard data of anode tension current power and exposure time were selected. When roentgen tube regime was changed, radiation loading diminished with increasing the radiation hardness. Normal roentgenograms were taken at a focus-object distance of 0.50 m and 1 m, the directly magnified ones - at 0.52 m and 0.75 m with precision focus (0.3x0.3 mm) and the tomograms - at a minimal distance of 1.25 m and a maximal one of 1.40 m. Measurements were performed without filter and with additional filtration: 1.5 mm and 3 mm aluminium. The integral superficial doses obtained with the additional radiological exploration, especially from the directly magnified films, were almost the same as with the routine roentgenograms. Because of the use of deep anti-diffuser diaphragms with light view-finder, additional radiation filtration and selection of optimal technical data, the dose were smaller than those published in the literature and the tentative ones, indicated in the reports of the Research Committee of the UNO in 1962 and 1972. (author)

  5. Dose-response relationship of γ-H2AX foci induction in human lymphocytes after X-rays exposure

    Biological dosimeters are recommended for dose estimation in case of human overexposure to ionising radiation. Rapid measurement of γ-H2AX foci as a marker of DNA double-strand breaks (DSB) induction has been recently tested with this purpose. Here we reported a dose-response relationship after X-ray irradiation at different times post-exposure. Blood samples were obtained from several healthy donors and exposed to doses between 0 and 2 Gy. After irradiation, blood samples were incubated at 37 deg. C during 0.5 h, 5 h, and 8 h. Scoring of cells and γ-H2AX foci was performed by software. The dose-response curves for different incubation times were as follows: Y(0.5h) = 11.66D + 0.15 (R2 = 0.99), Y(5h) = 2.44D + 0.15 (R2 = 0.99), Y(8h) = 1.57D + 0.22 (R2 = 0.99). At 0.5 h post-exposure, the dose-response relationship for X-irradiated lymphocytes was similar to the one obtained after gamma-irradiation using the same protocol. On the other hand, the results were not similar after 8 h due to different kinetics after gamma- and X-irradiation. Our results confirm the possibilities of using γ-H2AX foci method for dose estimation in a period from 0.5 h up to 8 h post X-irradiation and support the hypothesis of differences in γ-H2AX foci kinetics after gamma- and X-irradiation in vitro.

  6. Radiation-induced signaling results in mitochondrial impairment in mouse heart at 4 weeks after exposure to X-rays.

    Zarko Barjaktarovic

    Full Text Available BACKGROUND: Radiation therapy treatment of breast cancer, Hodgkin's disease or childhood cancers expose the heart to high local radiation doses, causing an increased risk of cardiovascular disease in the survivors decades after the treatment. The mechanisms that underlie the radiation damage remain poorly understood so far. Previous data show that impairment of mitochondrial oxidative metabolism is directly linked to the development of cardiovascular disease. METHODOLOGY/PRINCIPAL FINDINGS: In this study, the radiation-induced in vivo effects on cardiac mitochondrial proteome and function were investigated. C57BL/6N mice were exposed to local irradiation of the heart with doses of 0.2 Gy or 2 Gy (X-ray, 200 kV at the age of eight weeks, the control mice were sham-irradiated. After four weeks the cardiac mitochondria were isolated and tested for proteomic and functional alterations. Two complementary proteomics approaches using both peptide and protein quantification strategies showed radiation-induced deregulation of 25 proteins in total. Three main biological categories were affected: the oxidative phophorylation, the pyruvate metabolism, and the cytoskeletal structure. The mitochondria exposed to high-dose irradiation showed functional impairment reflected as partial deactivation of Complex I (32% and Complex III (11%, decreased succinate-driven respiratory capacity (13%, increased level of reactive oxygen species and enhanced oxidation of mitochondrial proteins. The changes in the pyruvate metabolism and structural proteins were seen with both low and high radiation doses. CONCLUSION/SIGNIFICANCE: This is the first study showing the biological alterations in the murine heart mitochondria several weeks after the exposure to low- and high-dose of ionizing radiation. Our results show that doses, equivalent to a single dose in radiotherapy, cause long-lasting changes in mitochondrial oxidative metabolism and mitochondria-associated cytoskeleton

  7. The influence of plutonium exposure and lung cancer on the frequency of x-ray-induced micronuclei in dog blood lymphocytes

    This study determined if lung cancer or exposure to an inhaled alpha emitter, plutonium-239, increased the frequency of micronuclei in blood lymphocytes or altered the responsiveness of lymphocytes to induction of micronuclei by subsequent doses of X rays in vitro. Beagle dogs inhaled 1.5 mm ABAD monodisperse 239PuO2 aerosols. The exposure resulted in initial lung burdens of 1.8 KBq to 48 KBq and produced cumulative alpha radiation lung doses of 1.4 to 10.4 Gy at the time of this study. Blood lymphocytes were sampled and irradiated with either 0.0 or 2.0 Gy of X rays. The lymphocytes were stimulated to divide by phytohemagglutinin, cytokinesis was blocked with cytochalasin B, and the frequency of micronuclei was determined in binucleated cells. Plutonium inhalation alone produced no significant increase in the frequency of micronuclei in blood lymphocytes. When 2 Gy of X rays ws given to blood lymphocytes of dogs that had inhaled 239PuO2 , there was a linear increase in micronuclei frequency as a function of alpha dose to the lungs; micronuclei/binucleated cell = 0.15 +0.2 D, where D is the cumulative alpha-radiation dose to the lung in Gy. Dogs with 239PuO2- induced lung cancer did not have a significant increase in the frequency of X- ray-induced micronuclei relative to dogs exposed to plutonium that did not have lung cancer. These data suggest that inhaled 239PuO2 alters the responsiveness of blood lymphocytes to subsequent X-ray exposure. (author)

  8. Assessment of targeted and non-targeted responses in cells deficient in ATM function following exposure to low and high dose X-rays.

    Anne Kiuru

    Full Text Available Radiation sensitivity at low and high dose exposure to X-rays was investigated by means of chromosomal aberration (CA analysis in heterozygous ATM mutation carrier and A-T patient (biallelic ATM mutation lymphoblastoid cell lines (LCLs. Targeted and non-targeted responses to acutely delivered irradiation were examined by applying a co-culture system that enables study of both directly irradiated cells and medium-mediated bystander effects in the same experimental setting. No indication of radiation hypersensitivity was observed at doses of 0.01 Gy or 0.1 Gy for the ATM mutation carrier LCL. The A-T patient cells also did not show low-dose response. There was significant increase in unstable CA yields for both ATM mutation carrier and A-T LCLs at 1 and 2 Gy, the A-T cells displaying more distinct dose dependency. Both chromosome and chromatid type aberrations were induced at an increased rate in the irradiated A-T cells, whereas for ATM carrier cells, only unstable chromosomal aberrations were increased above the level observed in the wild type cell line. No bystander effect could be demonstrated in any of the cell lines or doses applied. Characteristics typical for the A-T cell line were detected, i.e., high baseline frequency of CA that increased with dose. In addition, dose-dependent loss of cell viability was observed. In conclusion, CA analysis did not demonstrate low-dose (≤100 mGy radiosensitivity in ATM mutation carrier cells or A-T patient cells. However, both cell lines showed increased radiosensitivity at high dose exposure.

  9. Joint x-ray

    X-ray - joint; Arthrography; Arthrogram ... x-ray technologist will help you position the joint to be x-rayed on the table. Once in place, pictures are taken. The joint may be moved into other positions for more ...

  10. Radioresistant cell strain of human fibrosarcoma cells obtained after long-term exposure to X-rays

    A radioresistant cell strain from human fibrosarcoma HT1080 has been obtained after prolonged exposure to x-rays for 7 months (2 Gy per day, 5 days per week). This new strain, HT1080R, differs from HT1080 in a significantly increased ability of clonogenical survival, with coefficient α decreasing from 0.161 to 0.123 Gy-1 and coefficient β decreasing from 0.0950 to 0.0565 Gy-2. Furthermore, the radioresistance of HT1080R proved to be stable in long-term passaged cultures as well as in frozen samples. Differences between the two cell lines are also observed in the G-banded karyotype; the new cell line shows monosomy of chromosome 17 and loss of 5p+ and 11q+ present in the parental cells. These data suggest that the radioresistance may have been caused by radiation-induced cell mutation and that the resistant cells may have been selected by repeated irradiations. In order to characterize this new strain, the ability of the cells to rejoin DNA double-strand breaks, the cell cycle distribution and the amount of apoptosis after irradiation have been estimated; however, no differences are observed between these two cell strains. Although the mechanism of the elevated radioresistance remains unknown, this pair of cell strains can provide a new model system for further investigations with regard to the mechanisms of cellular radioresistance. The results also show that any type of irradiation similar to the schedules used in radiotherapy can lead to the formation and selection of more radioresistant cell clones in vitro, a phenomenon with possible implications for radiotherapy. (orig.)

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

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

  12. Optical transmission of glass for the National Ignition Facility near backscatter imagers under x-ray exposure

    In experiments at the National Ignition Facility (NIF), the near backscatter imager materials need to maintain high optical transmission while exposed to hohlraum generated x rays. Glass plates are incorporated in the design to protect the optical scattering plates from x-ray damage. Radiation environments spanning those expected on NIF have been produced at the Omega Laser Facility by symmetric laser illumination of 1 mm sized gold spheres. The time-dependent ultraviolet transmission of sample glass plates was measured. The data are interpreted with a free electron absorption model. Combined with the simulations of the hohlraum x-ray emission, this model is used to predict the transmission of the glass plates on the NIF. We predict that the plates should perform adequately up to the peak of the laser pulse.

  13. Influence of occupational exposure to pesticides on the level of DNA damage induced in human lymphocytes (Polish group) by UV-C and X-rays

    The aim of this study was to find out whether occupational exposure to pesticides might affect the individual susceptibility of various donors to the induction of DNA damage by genotoxic agents (UV-C, X-rays) and the efficiency of cellular repair. Previously cryo preserved lymphocytes were defrosted, and DNA damage in the lymphocytes prior to any in vitro studies was investigated with the application of the Comet assay. In order to evaluate the susceptibilities of human lymphocytes to genotoxic agents and the variability of repair capacities, the DNA migrations were estimated immediately after exposure to UV-C light or X-rays and after two hours. On average, the DNA damage detected in untreated lymphocytes was significantly higher in the group exposed to pesticides than in reference group. UV-C treated lymphocytes from group exposed to pesticides shows a greater statistically significant level of DNA migration compared to the reference group, detected after 2 hours incubation in the absence of PHA. Significantly lower responses to X-rays and higher levels of residual DNA damage were detected in the lymphocytes of donors from the group exposed to pesticides compared with the reference group. In conclusion, our results suggest that occupational exposure to pesticides influences the level of induced DNA damage, and the cellular capabilities of repair. (author)

  14. Environmental ionising radiation study: Assessment of the public exposure to the environmental gamma and X rays, and to radon in Antananarivo city

    Radioactivity is one of the indicators of the environmental state because humankind is continuously exposed to ionising radiations. Knowledge of the various components of this natural radioactivity becomes a necessity. As Antananarivo is the most populated city of Madagascar, its environmental radioactivity and radiation dose were assessed with the aim of establishing a database for radioactivity levels. The present work is entitled 'Assessment of the Public Exposure to the Environmental Gamma and X-rays, and to Radon in Antananarivo City'. This paper is the synthesis of several works carried out within the frame of a research project that lasted three years (April 1998-April 2001), consisting of more than a hundred in-situ measurements campaigns and laboratory sample analyses. Ionising radiations were measured through gamma and X ray global counting. Environmental material radioactivity was characterized by in-situ and laboratory gamma spectrometry. Alpha, gamma and X ray dosimetric measurements were done indoor and outdoor, in daytime and at night. The results obtained were the basis for three scientific communications at the Madagascar National Academy of Arts, Letters and Sciences. The first is entitled 'The Cesium-137 Artificial Radioisotope Pollution in Antananarivo City' (June 1998), the second 'the Atmospheric Radon in Antananarivo City '(May 1999), and the third 'Kerma in Air and Counting Rate of the Environmental Gamma and X Rays in Antananarivo City' (December 2000). From this work, the environmental gamma and X ray , and radon contribution to natural radiation doses were obtained. We have found that the population of Antananarivo is exposed to an annual average effective dose of 5.3 mSv.y-1, which is two times higher than the world quoted value.

  15. Comparative whole-body and part measurements for professional exposure to X-rays in dentists and their personnel

    In 85 per cent of all dentists and 94 per cent of their ponnel radiation doses received are smaller than 1/100 of the legally admissible dose. If the prescriptions for radiation protection are observed, neither professional group will be unduly exposed to X-rays. (orig.)

  16. Chest x-ray

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

  17. Effect of 5-azacytidine and acute X-ray irradiation on mice during sexual differentiation in utero

    Treatment for mice on the 12th day of gestation with 2 mg azazytidine/kg before or after 2 Gy X-ray-treatment led to a high-grade hypoplasia of the fetal telencephalon. In order to clarify reasons for the organ-specific effect of the combined treatment the author presently investigates - in addition to the CNS - the development of the testicles and observes the results of prenatal damages on fertility. Results obtained so far are discussed. (orig./MG)

  18. Acute pulmonary alveolar proteinosis due to exposure to cotton dust

    Thind Gurcharan

    2009-01-01

    Full Text Available Secondary pulmonary alveolar proteinosis (PAP is rare but may occur in association with malignancy, certain infections, and exposure to inorganic or organic dust and some toxic fumes. This case report describes the second recorded case of PAP due to exposure to cotton dust. A 24-year-old man developed PAP after working as a spinner for eight years without respiratory protection. He was admitted as an emergency patient with very severe dyspnea for four months and cough for several years. Chest X-ray showed bilateral diffuse alveolar consolidation. He died 16 days later, and a diagnosis of acute pulmonary alveolar proteinosis was made at autopsy. The histopathology demonstrated alveoli and respiratory bronchioles filled with characteristic periodic acid Schiff-positive material, which also revealed birefringent bodies of cotton dust under polarized light. Secondary PAP can be fatal and present with acute respiratory failure. The occupational history and characteristic pathology can alert clinicians to the diagnosis.

  19. Low energy (soft) x rays

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

  20. The Exposure of the Israeli Population to Ionizing Radiation due to Medical X-Ray Diagnostic Imaging

    The utilization of devices emitting ionizing radiation for medical diagnostic and therapeutic purposes is classified into 3 categories: a. Radio-therapy procedures for the treatment of malignant and benign tumors. b. Nuclear medicine procedures using radio-pharmaceuticals that are introduced into the patient's body for diagnostic and therapeutic purposes. c. Diagnostic and therapeutic x-ray imaging procedures. This group includes conventional radiography, conventional fluoroscopy, cardiac catheterization, angiography, CT, mammography, dental, and fluoroscopy operation procedures

  1. Emission of parasitic X-rays from military radar transmitters and exposure of personnel: towards a retrospective assessment

    An overview of the investigation of parasitic-X-ray (Bremsstrahlung) from high-voltage electron vacuum tubes in military radar transmitters is given. From technical inspection, data evaluation and measurements maximum dose rates for work places of the personnel are calculated. With dedicated workplace surveys the maximum dose H*(10) per month for the personnel is estimated for the entire time of use of the different radar sets. (author)

  2. Structural and histochemical considerations of parotid gland from adult rats (Holtzmann) submitted to x-rays exposure

    A histomorphological and histochemical study of the parotid gland of adult rats was carried out after subjecting the animals to a single X-ray irradiation dose of 900 R directed to the cervical region. The samples for the histological analysis were obtained at 2, 7, 15, 21, 30 and 45 days after radiation through desiccation and removal of the glands. The results showed clearly that the parotid gland is quite sensitive to X-ray irradiation with the serous acinar cells presenting heavier injuries than the mucous ones. A maximum in the deleterial action of the irradiation was detected at 15 days during the observation period. A comparative analysis of the glandular ducts showed that both of the types intercalated and striated were damaged, with the last presenting severe alterations in morphology and volume. By interpretation of the histochemical results it was concluded that a reduction in protein metabolism of the parotid gland occurred as a consequence of the X-ray irradiation. (author)

  3. Thoracic spine x-ray

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

  4. Modified fast rejoining of chromosomes after fractionated X-ray exposures with iron and copper sulfate pretreatments related to uptake detected by PIXE analysis in Nigella damascena seeds

    Nigella damascena dry seeds were irradiated with X-rays (250 kV) at fractionated exposures (2 × 40 and 2 × 20 Gy) separated by time intervals ranging from 120 to 240 s. A decrease of chromosome aberrations (threshold) observed with 60Co γ-rays between 130 and 140 s was confirmed. Some seeds were supplemented with FeSo4 or CuSo4. In unirradiated seeds, FeSO4 (at doses ranging from 1 × 10−5 to 1 × 10−2 M) induced a certain amount of chromosome damage, ostensibly on the basis of free radical production. FeSO4 (1 × 10−5 M) pretreatment considerably enhanced the frequency of chromosome aberrations induced by X-rays and suppressed the threshold observed in control experiments. CuSO4 (1 × 10−5 and 1 × 10−3 M) did not modify the initial level of chromosome aberrations (time intervals shorter than 130 s), but enhanced the final level (time intervals longer than 140 s), thus reversing the threshold. In the present experiments, no modifications of the proportions of various kinds of aberrations occurred as compared with the controls. The enrichment of seeds with each of the transition metals was measured with PIXE (particle-induced X-ray emission) in relation to the biological effects at the chromosome level. (author)

  5. Immunohistochemical study on cellular origins of rat lung tumors induced by inhalation exposures to plutonium dioxide aerosols as compared to those by X-ray irradiation

    Immunohistochemical examinations were performed on rat pulmonary tumors induced by inhalation exposures to 239PuO2 aerosols, or by X-ray-irradiation to identify and compare cellular origins or, in turn, target cells at risk for radiation carcinogenesis. Both plutonium-induced and X-ray-induced pulmonary tumors appeared to occur from the lower respiratory tract epithelium through bronchioles into alveoli, and were histopathologically diagnosed as adenoma, adenocarcinoma, adenosquamous carcinoma, and squamous cell carcinoma. Immunohistochemical staining of neoplastic lesions using rabbit polyclonal antibodies to rat surfactant apoprotein A specific for alveolar type II pneumocytes, and Clara cell antigen specific for nonciliated bronchiolar Clara cells, showed that most of the adenomatous and adenocarcinomatous lesions from plutonium-exposed or X-irradiated rats were positive for either or both antigens, while, in contrast, adenosquamous and squamous lesions were mostly negative for both antigens. Even though there were some differences in the proportions and distributions of immunoreactive cells between plutonium- and X-ray-induced tumors and among neoplastic lesions, the results indicate that radiation-induced pulmonary adenomas and adenocarcinomas mostly originate from either alveolar type II pneumocytes or bronchiolar Clara cells, while adenosquamous and squamous carcinomas may be derived from the other epithelial cell components, or might have lost specific antigenicity during their transforming differentiation. (author)

  6. Single-exposure low-dose x-ray imaging with grid-less and grid (GLG) imaging plates. A Kalman-filter approach

    Zoroofi, R.A.; Ogata, Yuji; Sato, Yoshinobu; Tamura, Shinichi; Inamoto, Kazuo [Osaka Univ. (Japan). Faculty of Medicine; Taketani, Hisashi; Shimojo, Shinji

    1998-11-01

    The present study was designed to monitor novel ideas in the acquisition and manipulation of data in an X-ray imaging system. A grid was sandwiched between two cascaded imaging plates (IPs). Using a fan-beam X-ray tube and a single exposure scheme, the two IPs, respectively, recorded grid-less and grid (GLG) type information of the object. Referring to the mathematical model of the GLG technique, it was explained that the collected data associated with the grid-less IP was of high (S/N) together with large scattered components whereas that of IP with grid was of low (S/N) and suppressed scattered components. Based on this assumption and using a Gaussian convolution kernel representing the effect of scattering, a technique was proposed to estimate scatter parameters of the GLG plates. Then, a Kalman-filter was developed to restore noisy-blurred images of the GLG techniques using the IPs data and estimated parameters. The results are shown for both the computer simulated and real X-ray phantom data. (author)

  7. Immunohistochemical study on cellular origins of rat lung tumors induced by inhalation exposures to plutonium dioxide aerosols as compared to those by X-ray irradiation

    Oghiso, Yoichi; Yamada, Yutaka [National Inst. of Radiological Sciences, Chiba (Japan)

    2002-09-01

    Immunohistochemical examinations were performed on rat pulmonary tumors induced by inhalation exposures to {sup 239}PuO{sub 2} aerosols, or by X-ray-irradiation to identify and compare cellular origins or, in turn, target cells at risk for radiation carcinogenesis. Both plutonium-induced and X-ray-induced pulmonary tumors appeared to occur from the lower respiratory tract epithelium through bronchioles into alveoli, and were histopathologically diagnosed as adenoma, adenocarcinoma, adenosquamous carcinoma, and squamous cell carcinoma. Immunohistochemical staining of neoplastic lesions using rabbit polyclonal antibodies to rat surfactant apoprotein A specific for alveolar type II pneumocytes, and Clara cell antigen specific for nonciliated bronchiolar Clara cells, showed that most of the adenomatous and adenocarcinomatous lesions from plutonium-exposed or X-irradiated rats were positive for either or both antigens, while, in contrast, adenosquamous and squamous lesions were mostly negative for both antigens. Even though there were some differences in the proportions and distributions of immunoreactive cells between plutonium- and X-ray-induced tumors and among neoplastic lesions, the results indicate that radiation-induced pulmonary adenomas and adenocarcinomas mostly originate from either alveolar type II pneumocytes or bronchiolar Clara cells, while adenosquamous and squamous carcinomas may be derived from the other epithelial cell components, or might have lost specific antigenicity during their transforming differentiation. (author)

  8. Synchrotron microscopic X-ray fluorescence analysis of the effects of chronic arsenic exposure in rat brain

    Synchrotron microscopic X-ray fluorescence (μ-SRXRF) scanning and conventional XRF analysis were applied for studying elemental concentrations in lyophilised brain rat slices. The animals received drinking water-100 ppm of sodium arsenite-ad libitum for 30 and 60 days. Accumulation of arsenic was corroborated and its dependence with arsenic dosage suggests the existence of a protection mechanism which limits the transport of inorganic arsenic to the brain. Chlorine, potassium and iron were reduced changing their spatial distributions while copper and zinc were redistributed

  9. Evidence for linear response for the induction of mutations in human cells by x-ray exposures below 10 rads.

    Grosovsky, A J; Little, J B

    1985-01-01

    The induction of 6-thioguanine resistance (6TGR) was studied in continuous human lymphoblast cultures exposed to daily x-ray doses of 1, 2.5, 5, or 10 rads (1 rad = 0.01 gray) for periods up to 1 month. Samples were taken every 5 days for determinations of induced mutation frequency. Cells receiving daily doses of 1-10 rads showed a mutation frequency of 0.069 X 10(-6) 6TGR cell per rad, virtually identical to the value of 0.062 X 10(-6) 6TGR cell per rad determined for lymphoblasts receiving...

  10. Dental x-rays

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

  11. X-ray apparatus

    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

  12. Chest X-Ray

    Full Text Available ... the most commonly performed x-ray exams and use a very small dose of ionizing radiation to ... to your health. While a chest x-ray use a tiny dose of ionizing radiation, the benefit ...

  13. X-ray (image)

    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 ...

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

    Tinggaard, J; Wohlfahrt-Veje, C; Husby, S;

    2016-01-01

    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) at age 10-15. Prenatal pesticide exposure was associated with increased total, android, and gynoid fat% (DXA) at age 10-15 years after adjustment for sex, socioeconomic status, and puberty (all β = 0.5 standard deviation score (SDS) p < 0.05). Stratified by sex, the associations were...

  15. Long-term exposure to a magnetic field (5 mT at 60 Hz) increases X-ray-induced mutations

    Exposure to extremely low frequency magnetic field (ELFMF) at 400 mT has been shown to induce mutations (Mutat. Res., 349: 109-114, 1996; Int. J. Radiat. Biol., 71: 75-79, 1997; and Biochem. Biophys. Res. Commun., 243: 579-584, 1998). However, whether ELFMF at low flux densities (under 1 mT) induces mutations is debatable. We investigated the effect of long-term exposure to 5 mT ELFMF at 60 Hz on mutant frequency. Chinese hamster ovary K1 (CHO-K1) cells were exposed or sham-exposed to 5 mT ELFMF for up to 6 weeks with or without X-irradiation (3 Gy), and the mutant frequency of the hypoxanthine-guanine phosphoribosyl transferase (HPRT) gene was analyzed. Long-term exposure to 5 mT ELFMF did not increase mutations, suggesting a threshold for mutation induction greater than 115 mA/m2 or a magnetic density of 5 mT. However, enhancement of the X-ray-induced mutation rate was observed after treatment with X-irradiation followed by long-term exposure to 5 mT ELFMF. At little as a 1-week exposure to ELFMF after X-irradiation enhanced the mutation rate. We also found that 400 mT exposure enhanced the mutation rate induced by X-irradiation (Mutat. Res., 349: 109-114, 1996). These results suggest that exposure to more than 5 mT ELFMF may promote X-ray-induced mutations. (author)

  16. X-Rays

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

  17. Chest X-Ray

    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 ...

  18. X-Ray Imaging

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

  19. X-ray spot film device

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

  20. Bone X-Ray (Radiography)

    Full Text Available ... 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. The effective radiation dose for this procedure varies. ...

  1. Bone X-Ray (Radiography)

    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. ...

  2. Bone X-Ray (Radiography)

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

  3. A method for distinguishing between static and dynamic X-ray exposure of a personal TL-badge using the CCD camera TL reader

    This paper reports initial attempts to apply a thermoluminescent (TL) reader with CCD camera to identify cases of static and dynamic exposure of personal dosemeters to doses relevant for radiation protection. Standard MTS-N (LiF:Mg,Ti) and MCP-N (LiF:Mg,Cu,P) TL pellets with diameter of 4.5 mm and thickness of 0.9 mm were used in a standard DOSACUS/RADOS personal dosimetry badge (holder). Pb, Cu and Al filters were installed instead of the standard Al 264 mg cm-2 filters used in the RADOS badge. The badges were exposed statically and dynamically to X-rays ranging from 28 keV (molybdenum anode) to 125 keV (tungsten anode) and to 137Cs (662 keV) gamma rays. The absorbed doses (in tissue) ranged from 20 to 100 mSv. Detectors were readout in the CCD reader and 2-D images were collected. The results obtained indicated that it was possible to identify the static, front exposure of the personal dosemeters equipped with Cu filter for doses >20 mGy for X-rays up to 125 keV. (authors)

  4. Behavior analysis in consumer affairs: encouraging dental professionals to provide consumers with shielding from unnecessary X-ray exposure

    An unobtrusive observation system was developed to determine the extent to which dental professionals in two communities provided lead shielding to patients during X-ray exams. A lengthy baseline revealed low and irregular provision of shielding among half of these professionals. Subsequently, a program was undertaken by a consumer's group in which these professionals were requested to provide shielding and were given confidential feedback regarding its use during the baseline period. The provision of shielding dramatically increased at all offices and was maintained throughout a follow-up period extending to more than 9 months after the program's implementation. Little or no generalized effect was observed in the occurrence of three collateral behaviors that were also assessed throughout the study

  5. Elemental changes in hemolymph and urine of Rhodnius prolixus induced by in-vivo exposure to mercury: A study using synchrotron radiation total reflection X-ray fluorescence

    Mantuano, Andrea; Pickler, Arissa; Barroso, Regina C.; de Almeida, André P.; Braz, Delson; Cardoso, Simone C.; Gonzalez, Marcelo S.; Figueiredo, Marcela B.; Garcia, Eloi S.; Azambuja, Patricia

    2012-05-01

    In recent years, the effects of pollution on the health of humans and other vertebrates were extensively studied. However, the effects on some invertebrates are comparatively unknown. Recent studies have demonstrated that toxic metals interfere with the reproduction, development and immune defenses of some terrestrial and marine invertebrates. Some environmental conditions including pollution produce chronic and acute effects on different animal's organs and systems. In this work, we investigated changes in the concentrations of Cl, K, Ca, Fe and Zn in Rhodnius prolixus as insect model. The elements were quantified using urine and hemolymph samples collected on different days after feeding the insects with blood containing HgCl2. The synchrotron radiation total reflection X-ray fluorescence measurements were carried at the X-ray fluorescence beamline facility in Brazilian Synchrotron Light Laboratory. The observation reveals that the calcium level was higher in the hemolymph than in urine. On the other hand, the urine collected from insects treated with HgCl2 showed higher level of Cl than hemolymph samples. Ca, Fe and Zn concentrations decrease drastically in urine samples collected after 2 days of HgCl2 treatment. The regulation of triatomines excretion was discussed pointing out the importance of trace elements.

  6. Interest of X-ray computed tomography and NMR tomography for the early diagnosis of acute localized irradiation. Experimental study in pigs

    Investigations were performed on 4 pigs, between 1 and 14 days after acute localized irradiation (with 192Ir) by X-ray computed tomography and NMR tomography. Areas irradiated with doses higher than 40 Gy could be visualized very early (on the 4th day) when no appearent lesions could be seen on histological samples according to classical pathology. Irradiated tissues at this high dose level are to necrose and surgery is the only practicable treatment. Therefore up to now that technique appears to be the only reliable one that could be used for an early and accurate assessment of the damages. Accordingly it should be suitable for pertinent surgical treatment. Further investigations are necessary to set more close relations between imaging, pathology and dose

  7. Dental X-ray apparatus

    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)

  8. Marked increase in the rate of ocular lens and forelimb regeneration in the newt. Cynops pyrrhogaster, following partial body exposure to low dose X-rays

    Okamoto, T.; Kanao, T.; Miyachi, Y.

    2004-07-01

    In recent years, concern over the stimulating effects of low-dose X-rays has been growing. Therefore the effects of low-dose X-irradiation on lens and forelimb regeneration in the newt were examined. Newts were subjected to s harm or whole-body X-ray exposure at a dose of 0.05, 0.2 or 0.4Gy, delivered at a rate of 0.43Gy/min. The eyeballs were fixed in formalin solution, embedded in paraffin and assessed histologically. On day 14 after lens removal, unexposed animals showed the formation of a hollow epithelial vesicle of depigmented cells continuous with the laminae of the iris corresponding to the expected regeneration stage (Reyer's regeneration stage II). In contrast, lenses from newts exposed to a 0.2Gy dose X-ray showed some formation of the primary lens fiber nucleus corresponding to the fiber differentiation stage (Reyer's regeneration stage III-early). Thus, low-dose X-irradiation induced well regeneration compared to the unexposed groups. However, when newts were injected with N-nitro-L-arginine, nitric oxide inhibitor, no radiation-induced effect could be observed. Furthermore, an acceleration from Reyer's stage II to III-early was also found on day 14 following irradiation of only the upper belly, including the spleen. Interestingly, well regeneration could be observed on forelimb stage. On 6 weeks after amputation, unexposed animal was showed the assembly of the condrogenesis of the radius and ulna. In contrast, forelimb from newts exposed to a 0.2Gy spleen portion was showed the onset of digit formation. The effects of low-dose X-irradiation on regeneration may be mediated by changes in immune activity. (Author)

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

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

  10. Analgesia induced by repeated exposure to low dose X-rays in mice, and involvement of the accessory olfactory system in modulation of the radiation effects

    The effects of low-dose X-rays on mouse nociceptive behavior were examined using a formalin injected test which rated the amount of time the animals spent licking the injected hind-paw. Male ICR White Swiss mice showed a marked suppression of licking behavior after repeated low-dose X-irradiation (5 cGy/day, 6 consecutive days). The most profound effect was observed on the day 30 after irradiation. The decline of licking behavior, however, was not observed at all following olfactory bulbectomy or vomeronasal tract cut. The analgesic effects could be observed in writhing animals administered acetic-acid intraperitoneally. Moreover, analgesia was totally blocked by the administration of N-nitro-L-arginine, a nitric oxide synthase inhibitor, to accessory olfactory bulbs prior to the exposure. The present results indicate that the olfactory system plays an important role in modulation of radiation-induced analgesia, and a possible involvement of nitric oxide in the formation of recognition memory subjected to repeated X-rays. Relatively higher doses (5 cGy x 9 days, 5 cGy x 12 days), however, did not induce such effects, namely, the decline of nociceptive response was limited to the animals irradiated with the smaller dose. (author)

  11. X-Ray Polarimetry

    Kaaret, Philip

    2014-01-01

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

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

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

  13. Instrument and method for X-ray diffraction, fluorescence, and crystal texture analysis without sample preparation

    Gendreau, Keith (Inventor); Martins, Jose Vanderlei (Inventor); Arzoumanian, Zaven (Inventor)

    2010-01-01

    An X-ray diffraction and X-ray fluorescence instrument for analyzing samples having no sample preparation includes a X-ray source configured to output a collimated X-ray beam comprising a continuum spectrum of X-rays to a predetermined coordinate and a photon-counting X-ray imaging spectrometer disposed to receive X-rays output from an unprepared sample disposed at the predetermined coordinate upon exposure of the unprepared sample to the collimated X-ray beam. The X-ray source and the photon-counting X-ray imaging spectrometer are arranged in a reflection geometry relative to the predetermined coordinate.

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

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

  15. X-ray - skeleton

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

  16. Extremity x-ray

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

  17. X-ray interferometers

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

  18. Dental x-rays

    ... addition, many dentists are taking x-rays using digital technology. The image runs through a computer. The amount of radiation given off during the procedure is less than traditional methods. Other types of dental x-rays can create a 3-D picture ...

  19. Elemental changes in hemolymph and urine of Rhodnius prolixus induced by in-vivo exposure to mercury: A study using synchrotron radiation total reflection X-ray fluorescence

    In recent years, the effects of pollution on the health of humans and other vertebrates were extensively studied. However, the effects on some invertebrates are comparatively unknown. Recent studies have demonstrated that toxic metals interfere with the reproduction, development and immune defenses of some terrestrial and marine invertebrates. Some environmental conditions including pollution produce chronic and acute effects on different animal's organs and systems. In this work, we investigated changes in the concentrations of Cl, K, Ca, Fe and Zn in Rhodnius prolixus as insect model. The elements were quantified using urine and hemolymph samples collected on different days after feeding the insects with blood containing HgCl2. The synchrotron radiation total reflection X-ray fluorescence measurements were carried at the X-ray fluorescence beamline facility in Brazilian Synchrotron Light Laboratory. The observation reveals that the calcium level was higher in the hemolymph than in urine. On the other hand, the urine collected from insects treated with HgCl2 showed higher level of Cl than hemolymph samples. Ca, Fe and Zn concentrations decrease drastically in urine samples collected after 2 days of HgCl2 treatment. The regulation of triatomines excretion was discussed pointing out the importance of trace elements. - Highlights: ► Changes in Cl, K, Ca, Fe and Zn contents in Rhodnius prolixus were evaluated. ► In triatomines these elements have not been previously described. ► Cl, Ca, Zn levels were lower than control in hemolymph after 5 days of HgCl2 fed. ► Cl, Ca, Zn levels were higher than control in urine after 2 days of HgCl2 fed.

  20. Elemental changes in hemolymph and urine of Rhodnius prolixus induced by in-vivo exposure to mercury: A study using synchrotron radiation total reflection X-ray fluorescence

    Mantuano, Andrea, E-mail: mantuanoandrea@gmail.com [Physics Institute, State University of Rio de Janeiro (Brazil); Pickler, Arissa; Barroso, Regina C. [Physics Institute, State University of Rio de Janeiro (Brazil); Almeida, Andre P. de; Braz, Delson [Nuclear Engineering Program, Federal University of Rio de Janeiro (Brazil); Cardoso, Simone C. [Physics Institute, Federal University of Rio de Janeiro (Brazil); Gonzalez, Marcelo S. [Department of General Biology, Fluminense Federal University (Brazil); Figueiredo, Marcela B.; Garcia, Eloi S.; Azambuja, Patricia [Laboratory of Biochemistry and Physiology of Insects, Oswaldo Cruz Foundation (Brazil)

    2012-05-15

    In recent years, the effects of pollution on the health of humans and other vertebrates were extensively studied. However, the effects on some invertebrates are comparatively unknown. Recent studies have demonstrated that toxic metals interfere with the reproduction, development and immune defenses of some terrestrial and marine invertebrates. Some environmental conditions including pollution produce chronic and acute effects on different animal's organs and systems. In this work, we investigated changes in the concentrations of Cl, K, Ca, Fe and Zn in Rhodnius prolixus as insect model. The elements were quantified using urine and hemolymph samples collected on different days after feeding the insects with blood containing HgCl{sub 2}. The synchrotron radiation total reflection X-ray fluorescence measurements were carried at the X-ray fluorescence beamline facility in Brazilian Synchrotron Light Laboratory. The observation reveals that the calcium level was higher in the hemolymph than in urine. On the other hand, the urine collected from insects treated with HgCl{sub 2} showed higher level of Cl than hemolymph samples. Ca, Fe and Zn concentrations decrease drastically in urine samples collected after 2 days of HgCl{sub 2} treatment. The regulation of triatomines excretion was discussed pointing out the importance of trace elements. - Highlights: Black-Right-Pointing-Pointer Changes in Cl, K, Ca, Fe and Zn contents in Rhodnius prolixus were evaluated. Black-Right-Pointing-Pointer In triatomines these elements have not been previously described. Black-Right-Pointing-Pointer Cl, Ca, Zn levels were lower than control in hemolymph after 5 days of HgCl{sub 2} fed. Black-Right-Pointing-Pointer Cl, Ca, Zn levels were higher than control in urine after 2 days of HgCl{sub 2} fed.

  1. The Medical Exposure to Ionizing Radiation and Protection of the Patient in Medical Imaging Procedures for Diagnostic and Therapeutic Purposes (Excluding Radiotherapy) using X-Rays in Israel - Risk - Cost and Benefit

    Diagnostic and therapeutic radiology is playing a major role in modern medicine. The utilization of devices emitting ionizing radiation for medical diagnostic and therapeutic purposes is classified into three categories: a. Radiotherapy procedures for the treatment of malignant and benign tumors. b. Nuclear medicine procedures using radiopharmaceuticals that are introduced into the patient's body for diagnostic and therapeutic purposes. c. Diagnostic and therapeutic x-ray imaging procedures. This group includes conventional radiography, conventional fluoroscopy, cardiac catheterization, angiography, CT, mammography, dental, and fluoroscopy operation procedures. A survey was carried out on a sample of three major Israeli hospitals in order to: 1. Determine the status of radiation protection of patients in Israel with regard to the use of x-rays in medical imaging and interventional radiology. 2. Assess the extent of exposure of the population to medical x-rays, and assess the collective risk in Israel in this relation (based on Icr-60). 3. Carry out a cost-benefit optimization procedure related to the means that should be used to reduce the exposure of Israeli patients under x-ray procedures. 4. Establish a of practical recommendations to reduce the x-ray radiation exposure of patients and to increase the image quality. 5. Establish a number of basic rules to be utilized by health policy makers in Israel

  2. Exposure and analysis of microparticles embedded in silica aerogel keystones using NF3-mediated electron beam-induced etching and energy-dispersive X-ray spectroscopy

    Martin, Aiden A.; Lin, Ting; Toth, Milos; Westphal, Andrew J.; Vicenzi, Edward P.; Beeman, Jeffrey; Silver, Eric H.

    2016-04-01

    In 2006, NASA's Stardust spacecraft delivered to Earth dust particles collected from the coma of comet 81P/Wild 2, with the goal of furthering the understanding of solar system formation. Stardust cometary samples were collected in a low-density, nanoporous silica aerogel making their study technically challenging. This article demonstrates the identification, exposure, and elemental composition analysis of particles analogous to those collected by NASA's Stardust mission using in-situ SEM techniques. Backscattered electron imaging is shown by experimental observation and Monte Carlo simulation to be suitable for locating particles of a range of sizes relevant to Stardust (down to submicron diameters) embedded within silica aerogel. Selective removal of the silica aerogel encapsulating an embedded particle is performed by cryogenic NF3-mediated electron beam-induced etching. The porous, low-density nature of the aerogel results in an enhanced etch rate compared with solid material, making it an effective, nonmechanical method for the exposure of particles. After exposure, elemental composition of the particle was analyzed by energy-dispersive X-ray spectroscopy using a high spectral resolution microcalorimeter. Signals from fluorine contamination are shown to correspond to nonremoved silica aerogel and only in residual concentrations.

  3. Exposure and analysis of microparticles embedded in silica aerogel keystones using NF3-mediated electron beam-induced etching and energy-dispersive X-ray spectroscopy

    Martin, Aiden A.; Lin, Ting; Toth, Milos; Westphal, Andrew J.; Vicenzi, Edward P.; Beeman, Jeffrey; Silver, Eric H.

    2016-07-01

    In 2006, NASA's Stardust spacecraft delivered to Earth dust particles collected from the coma of comet 81P/Wild 2, with the goal of furthering the understanding of solar system formation. Stardust cometary samples were collected in a low-density, nanoporous silica aerogel making their study technically challenging. This article demonstrates the identification, exposure, and elemental composition analysis of particles analogous to those collected by NASA's Stardust mission using in-situ SEM techniques. Backscattered electron imaging is shown by experimental observation and Monte Carlo simulation to be suitable for locating particles of a range of sizes relevant to Stardust (down to submicron diameters) embedded within silica aerogel. Selective removal of the silica aerogel encapsulating an embedded particle is performed by cryogenic NF3-mediated electron beam-induced etching. The porous, low-density nature of the aerogel results in an enhanced etch rate compared with solid material, making it an effective, nonmechanical method for the exposure of particles. After exposure, elemental composition of the particle was analyzed by energy-dispersive X-ray spectroscopy using a high spectral resolution microcalorimeter. Signals from fluorine contamination are shown to correspond to nonremoved silica aerogel and only in residual concentrations.

  4. X-ray crystallography

    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.

  5. Photon-exposure-dependent photon-stimulated desorption for obtaining photolysis cross section of molecules adsorbed on surface by monochromatic soft x-ray photons

    Photon-exposure-dependent positive- and negative-ion photon-stimulated desorption (PSD) was proposed to study the photoreactions and obtain the photolysis cross sections of molecules adsorbed on a single-crystal surface by monochromatic soft x-ray photons with energy near the core level of adsorbate. The changes in the F+ and F- PSD ion yields were measured from CF3Cl molecules adsorbed on Si(111)-7x7 at 30 K (CF3Cl dose=0.3x1015 molecules/cm2, ∼0.75 monolayer) during irradiation of monochromatic soft x-ray photons near the F(1s) edge. The PSD ion yield data show the following characteristics: (a) The dissociation of adsorbed CF3Cl molecules is due to a combination of direct photodissociation via excitation of F(1s) core level and substrate-mediated dissociation [dissociative attachment and dipolar dissociation induced by the photoelectrons emitting from the silicon substrate]. (b) the F+ ion desorption is associated with the bond breaking of the surface CF3Cl, CF2Cl, CFCl, and SiF species. (c) the F- yield is mainly due to DA and DD of the adsorbed CF3Cl molecules. (d) The surface SiF is formed by reaction of the surface Si atom with the neutral fluorine atom, F+, or F- ion produced by scission of C-F bond of CF3Cl, CF2Cl, or CFCl species. A kinetic model was proposed for the explanation of the photolysis of this submonolayer CF3Cl-covered surface. Based on this model and the variation rates of the F+/F- signals during fixed-energy monochromatic photon bombardment at 690.2 and 692.6 eV[near the F(1s) edge], the photolysis cross section was deduced as a function of energy.

  6. Bone X-Ray (Radiography)

    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 ...

  7. Bone X-Ray (Radiography)

    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 ...

  8. Bone X-Ray (Radiography)

    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 ...

  9. Lumbosacral spine x-ray

    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 ...

  10. Bone X-Ray (Radiography)

    ... 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 ...

  11. Abdomen X-Ray (Radiography)

    ... 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 ...

  12. X-ray apparatus

    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.)

  13. X-ray lasers

    Elton, Raymond C

    2012-01-01

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

  14. X-Ray Exam: Lower Leg (Tibia and Fibula)

    ... Your Child All About Food Allergies X-Ray Exam: Lower Leg (Tibia and Fibula) KidsHealth > For Parents > X-Ray Exam: Lower Leg (Tibia and Fibula) Print A A ... procedure. Although the tibia and fibula X-ray exam may take about 15 minutes, actual exposure to ...

  15. Chest X-Ray

    Full Text Available ... also be useful to help diagnose and monitor treatment for a variety of lung conditions such as pneumonia, emphysema and cancer. A chest x-ray requires no special preparation. ...

  16. Chest X-Ray

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

  17. X-Ray Diffraction.

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

    1980-01-01

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

  18. Medical X-Rays

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

  19. Chest X-Ray

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

  20. Chest X-Ray

    Full Text Available ... of ionizing radiation, the benefit of an accurate diagnosis far outweighs any risk. For more information about chest x-rays, visit Radiology Info dot org. Thank you for your time! ...

  1. Chest X-Ray

    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 ...

  2. Chest X-Ray

    Full Text Available ... Site Index A-Z Spotlight June is Men's Health Month Recently posted: Focused Ultrasound for Uterine Fibroids ... to consider the likelihood of benefit to your health. While a chest x-ray use a tiny ...

  3. Risk estimates for meningiomas and other late effects after diagnostic X-ray exposure of the skull

    This study aims to investigate the contribution of diagnostic exposures to the rising rates of brain tumours and other neoplasms which are observed in several industrial nations. Included are benign tumours in the head and neck region and cataracts which are neglected in usual risk estimates by international and national radiation protection committees. Dose-effect relationships for tumours of the brain, skin, thyroid and other sites of the head region, leukaemia and cataracts are taken from the literature. Risk estimates are derived for paediatric head computed tomographies (CTs) as well as for brain tumours in adults. On the basis of estimates for Germany about the number of head scans, the annual rate of radiation-induced diseases is calculated. About 1000 annual paediatric CT investigations of the skull will lead to about three excess neoplasms in the head region, i.e. the probability of an induced late effect must be suspected in the range of some thousands. Additionally, a relevant increase of cataracts must be considered. The radiation-induced occurrence of meningiomas and other brain tumours most probably contributes to the continuously increasing incidence of these diseases which is observed in several industrial nations, as well as the exposure of the bone marrow by CT to the increase of childhood leukaemia. (authors)

  4. Bone X-Ray (Radiography)

    Full Text Available ... around or in bones. top of page How should I prepare? Most bone x-rays require no ... might interfere with the x-ray images. Women should always inform their physician and x-ray technologist ...

  5. Bone X-Ray (Radiography)

    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 ...

  6. Bone X-Ray (Radiography)

    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 controlled x-ray beams and dose ...

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

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

  8. X-ray laser

    X-ray is among the most important research tools today, and has given priceless contributions to all disciplines within the natural sciences. State of the art in this field is called XFEL, X-ray Free Electron Laser, which may be 10 thousand million times stronger than the x-rays at the European Synchrotron Radiation Facility in Grenoble. In addition XFEL has properties that allow the study of processes which previously would have been impossible. Of special interest are depictions on atomic- and molecular level by the use of x-ray holographic methods, and being able to study chemical reactions in nature's own timescale, the femtosecond. Conclusion: The construction of x-ray lasers is a natural development in a scientific field which has an enormous influence on the surrounding society. While the discovery of x-ray was an important breakthrough in itself, new applications appear one after the other: Medical depiction, dissemination, diffraction, DNA and protein structures, synchrotron radiation and tomography. There is reason to believe that XFEL implies a technological leap as big as the synchrotrons some decades ago. As we are now talking about studies of femtosecond and direct depiction of chemical reactions, it is obvious that we are dealing with a revolution to come, with extensive consequences, both scientifically and culturally. (EW)

  9. Methylation changes in muscle and liver tissues of male and female mice exposed to acute and chronic low-dose X-ray-irradiation

    The biological and genetic effects of chronic low-dose radiation (LDR) exposure and its relationship to carcinogenesis have received a lot of attention in the recent years. For example, radiation-induced genome instability, which is thought to be a precursor of tumorogenesis, was shown to have a transgenerational nature. This indicates a possible involvement of epigenetic mechanisms in LDR-induced genome instability. Genomic DNA methylation is one of the most important epigenetic mechanisms. Existing data on radiation effects on DNA methylation patterns is limited, and no one has specifically studied the effects of the LDR. We report the first study of the effects of whole-body LDR exposure on global genome methylation in muscle and liver tissues of male and female mice. In parallel, we evaluated changes in promoter methylation and expression of the tumor suppressor gene p16INKa and DNA repair gene O6-methylguanine-DNA methyltransferase (MGMT). We observed different patterns of radiation-induced global genome DNA methylation in the liver and muscle of exposed males and females. We also found sex and tissue-specific differences in p16INKa promoter methylation upon LDR exposure. In male liver tissue, p16INKa promoter methylation was more pronounced than in female tissue. In contrast, no significant radiation-induced changes in p16INKa promoter methylation were noted in the muscle tissue of exposed males and females. Radiation also did not significantly affect methylation status of MGMT promoter. We also observed substantial sex differences in acute and chronic radiation-induced expression of p16INKa and MGMT genes. Another important outcome of our study was the fact that chronic low-dose radiation exposure proved to be a more potent inducer of epigenetic effects than the acute exposure. This supports previous findings that chronic exposure leads to greater genome destabilization than acute exposure

  10. Methylation changes in muscle and liver tissues of male and female mice exposed to acute and chronic low-dose X-ray-irradiation.

    Kovalchuk, Olga; Burke, Paula; Besplug, Jill; Slovack, Mark; Filkowski, Jody; Pogribny, Igor

    2004-04-14

    The biological and genetic effects of chronic low-dose radiation (LDR) exposure and its relationship to carcinogenesis have received a lot of attention in the recent years. For example, radiation-induced genome instability, which is thought to be a precursor of tumorogenesis, was shown to have a transgenerational nature. This indicates a possible involvement of epigenetic mechanisms in LDR-induced genome instability. Genomic DNA methylation is one of the most important epigenetic mechanisms. Existing data on radiation effects on DNA methylation patterns is limited, and no one has specifically studied the effects of the LDR. We report the first study of the effects of whole-body LDR exposure on global genome methylation in muscle and liver tissues of male and female mice. In parallel, we evaluated changes in promoter methylation and expression of the tumor suppressor gene p16(INKa) and DNA repair gene O(6)-methylguanine-DNA methyltransferase (MGMT). We observed different patterns of radiation-induced global genome DNA methylation in the liver and muscle of exposed males and females. We also found sex and tissue-specific differences in p16(INKa) promoter methylation upon LDR exposure. In male liver tissue, p16(INKa) promoter methylation was more pronounced than in female tissue. In contrast, no significant radiation-induced changes in p16(INKa) promoter methylation were noted in the muscle tissue of exposed males and females. Radiation also did not significantly affect methylation status of MGMT promoter. We also observed substantial sex differences in acute and chronic radiation-induced expression of p16(INKa) and MGMT genes. Another important outcome of our study was the fact that chronic low-dose radiation exposure proved to be a more potent inducer of epigenetic effects than the acute exposure. This supports previous findings that chronic exposure leads to greater genome destabilization than acute exposure. PMID:15063138