WorldWideScience

Sample records for fluoroscopic dose assessment

  1. An assessment of methods for monitoring entrance surface dose in fluoroscopically guided interventional procedures

    International Nuclear Information System (INIS)

    Waite, J.C.; Fitzgerald, M.

    2001-01-01

    In the light of a growing awareness of the risks of inducing skin injuries as a consequence of fluoroscopically guided interventional procedures (FGIPs), this paper compares three methods of monitoring entrance surface dose (ESD). It also reports measurements of ESDs made during the period August 1998 to June 1999 on 137 patients undergoing cardiac, neurological and general FGIPs. Although the sample is small, the results reinforce the need for routine assessments to be made of ESDs in FGIPs. At present, the most reliable and accurate form of ESD measurement would seem to be arrays of TLDs. However, transducer based methods, although likely to be less accurate, have considerable advantages in relation to a continuous monitoring programme. It is also suggested that there may be the potential locally for threshold dose area product (DAP) values to be set for specific procedures. These could be used to provide early warning of the potential for skin injuries. (author)

  2. Image quality evaluation and patient dose assessment of medical fluoroscopic X-ray systems: A national study

    International Nuclear Information System (INIS)

    Economides, S.; Hourdakis, C. J.; Kalivas, N.; Kalathaki, M.; Simantirakis, G.; Tritakis, P.; Manousaridis, G.; Vogiatzi, S.; Kipouros, P.; Boziari, A.; Kamenopoulou, V.

    2008-01-01

    This study presents the results from a survey conducted by the Greek Atomic Energy Commission (GAEC), during the period 1998-2003, in 530 public and private owned fluoroscopic X-ray systems in Greece. Certain operational parameters for conventional and remote control systems were assessed, according to a quality control protocol developed by GAEC on the basis of the current literature. Public (91.5%) and private (81.5%) owned fluoroscopic units exhibit high-contrast resolution values over 1 lp mm -1 . Moreover, 88.5 and 87.1% of the fluoroscopic units installed in the public and private sector, respectively, present Maximum Patient Entrance Kerma Rate values lower than 100 mGy min -1 . Additionally, 68.3% of the units assessed were found to perform within the acceptance limits. Finally, the third quartile of the Entrance Surface Dose Rate distribution was estimated according to the Dose Reference Level definition and found equal to 35 mGy min -1 . (authors)

  3. Patient dose assessment from fluoroscopic procedures at Korle-Bu Teaching Hospital

    International Nuclear Information System (INIS)

    Gyekye, P. K.

    2008-06-01

    Organ and effective dose to ninety (90) patients undergoing myelogram, urethrogram, barium swallow, barium meal and barium enema examinations at the KorIe-Bu Teaching Hospital was estimated using the Monte Carlo Code (PCXMC). Free in air measurements were made with a calibrated ionisation chamber to estimate the entrance surface air kerma for each examination. Evaluation of fluoroscopy beam on time and number of radiographs taken per patient was done for all the examinations considered and studies were done on how they affect patient dose. Dose area product (DAP) was calculated from the entrance surface air kerma and the area of the beam on the surface of the patient and compared with internationally accepted reference levels. Excess relative risk of site specific solid cancer and all solid cancers excluding thyroid and Non-melanoma skin cancers incidences were estimated for the various examinations using Biological Effects of Ionising Radiation VII Committee risk model from the knowledge of the mean effective doses for each examination. The mean effective dose was found to be 0.29 :±: 0.07 mSv for urethrogram, 0.84:±: 0.13 mSv for barium swallow, 3.15 :±: 0.44 mSv for barium meal, 6.24 :±: 0.7 mSv for barium enema and 0.38 :I: 0.05 mSv for myelogram examinations. The estimated mean dose area product (DAP) was found to be 3.55 :±: 0.95 Gycm2 for urethrogram, 16.44:1: 2.60 Gycm2 for barium swallow, 50.81 :±: 7.04 Gycm2 for barium meal, 99.69 :±: 10.85 Gycm2 for barium enema and 9.32 :±: 0.99 Gycm2 for myelogram examinations. The estimated excess relative risk for the occurrence of all solid cancer was found to be 9.5700E-S and 1.6530E-4 for males and females respectively undergoing urethrogram examination, 2.7720E-4 and 4.7880E-4 for males and females respectively undergoing barium swallow examination, 1.0395E-3 and 1.7955E-3 for males and females respectively undergoing barium meal examination, 2.0592E-3 and 3.5568E-3 for males and females respectively

  4. Skin dose mapping for fluoroscopically guided interventions.

    Science.gov (United States)

    Johnson, Perry B; Borrego, David; Balter, Stephen; Johnson, Kevin; Siragusa, Daniel; Bolch, Wesley E

    2011-10-01

    To introduce a new skin dose mapping software system for interventional fluoroscopy dose assessment and to analyze the benefits and limitations of patient-phantom matching. In this study, a new software system was developed for visualizing patient skin dose during interventional fluoroscopy procedures. The system works by translating the reference point air kerma to the location of the patient's skin, which is represented by a computational model. In order to orient the model with the x-ray source, geometric parameters found within the radiation dose structured report (RDSR) are used along with a limited number of in-clinic measurements. The output of the system is a visual indication of skin dose mapped onto an anthropomorphic model at a resolution of 5 mm. In order to determine if patient-dependent and patient-sculpted models increase accuracy, peak skin dose was calculated for each of 26 patient-specific models and compared with doses calculated using an elliptical stylized model, a reference hybrid model, a matched patient-dependent model and one patient-sculpted model. Results were analyzed in terms of a percent difference using the doses calculated using the patient-specific model as the true standard. Anthropometric matching, including the use of both patient-dependent and patient-sculpted phantoms, was shown most beneficial for left lateral and anterior-posterior projections. In these cases, the percent difference using a reference model was between 8 and 20%, using a patient-dependent model between 7 and 15%, and using a patient-sculpted model between 3 and 7%. Under the table tube configurations produced errors less than 5% in most situations due to the flattening affects of the table and pad, and the fact that table height is the main determination of source-to-skin distance for these configurations. In addition to these results, several skin dose maps were produced and a prototype display system was placed on the in-clinic monitor of an interventional

  5. Assessment of radiation dose due to fluoroscopic procedures in patients at some selected facilities in the Greater Accra Region, Ghana

    International Nuclear Information System (INIS)

    Gyasi, E.

    2013-07-01

    Radiation doses to 182 adults patients who underwent barium enema, barium meal, barium swallow, myelogram, hysterosalpingography and urethrogram examination collectively at facilities A and B were investigated. Radiation dose was measured using kerma-area-product (KAP) meter. From the KAP readings, patient's data and other relevant information from the control console, effective dose and selective organ doses were estimated using Monte Carlo program software (PCXMC version 1.5). Quality control tests performed on the two fluoroscopy machines were found to be within the acceptance criteria. Mean effective doses were found to be 8.45 ± 0.38mSv, 7.628 ± 0.42 mSv, 1.46 ± 0.13 mSv, 2.02 ± 0.16 mSv, 0.32 ± 0.03 mSv for barium enema, barium meal, barium swallow, myelogram and urethrogram examinations respectively at Facility A. At Facility B the mean effective dose were found to be 4.12 ± 0.15 mSv, 1.83 ± 0.10 mSv, 0.81 ± 0.04 mSv, 0.53 ± 0.036 mSv and 0.27 ± 0.01 mSv for barium enema, barium meal, barium swallow, myelogram, hysterosalpingography and urethrogram examination respectively. Thymus received the highest organ dose of 29.19± 2.07mGy during barium meal studies at Facility A of all the procedures in the two hospitals. Magnitude of organ doses was observed to to be in relation with the closeness to or in the direction of the primary beam of radiation. Organ and effective doses from Facility A were relatively higher than those from Facility B in comparison by a factor of a about 2 with the exception of the barium meal examination at Facility A which was by a factor of about 4. The measured KAP readings fro the two facilities were below the international accepted reference levels with the exception of barium meal examination at Facility A which recorded a higher value of 25.96 ± 1.83 Gy.cm 2 as compared to ICRP (2001) reference value of 25 Gy.cm 2 . Longer radiation beam on time, high number of radiographs taken per patient, wide exposure beam area on

  6. Management of pediatric radiation dose using GE fluoroscopic equipment

    International Nuclear Information System (INIS)

    Belanger, Barry; Boudry, John

    2006-01-01

    In this article, we present GE Healthcare's design philosophy and implementation of X-ray imaging systems with dose management for pediatric patients, as embodied in its current radiography and fluoroscopy and interventional cardiovascular X-ray product offerings. First, we present a basic framework of image quality and dose in the context of a cost-benefit trade-off, with the development of the concept of imaging dose efficiency. A set of key metrics of image quality and dose efficiency is presented, including X-ray source efficiency, detector quantum efficiency (DQE), detector dynamic range, and temporal response, with an explanation of the clinical relevance of each. Second, we present design methods for automatically selecting optimal X-ray technique parameters (kVp, mA, pulse width, and spectral filtration) in real time for various clinical applications. These methods are based on an optimization scheme where patient skin dose is minimized for a target desired image contrast-to-noise ratio. Operator display of skin dose and Dose-Area Product (DAP) is covered, as well. Third, system controls and predefined protocols available to the operator are explained in the context of dose management and the need to meet varying clinical procedure imaging demands. For example, fluoroscopic dose rate is adjustable over a range of 20:1 to adapt to different procedure requirements. Fourth, we discuss the impact of image processing techniques upon dose minimization. In particular, two such techniques, dynamic range compression through adaptive multiband spectral filtering and fluoroscopic noise reduction, are explored in some detail. Fifth, we review a list of system dose-reduction features, including automatic spectral filtration, virtual collimation, variable-rate pulsed fluoroscopic, grid and no-grid techniques, and fluoroscopic loop replay with store. In addition, we describe a new feature that automatically minimizes the patient-to-detector distance, along with an

  7. Measuring radiation dose to patients undergoing fluoroscopically-guided interventions

    International Nuclear Information System (INIS)

    Lubis, L E; Badawy, M K

    2016-01-01

    The increasing prevalence and complexity of fluoroscopically guided interventions (FGI) raises concern regarding radiation dose to patients subjected to the procedure. Despite current evidence showing the risk to patients from the deterministic effects of radiation (e.g. skin burns), radiation induced injuries remain commonplace. This review aims to increase the awareness surrounding radiation dose measurement for patients undergoing FGI. A review of the literature was conducted alongside previous researches from the authors’ department. Studies pertaining to patient dose measurement, its formalism along with current advances and present challenges were reviewed. Current patient monitoring techniques (using available radiation dosimeters), as well as the inadequacy of accepting displayed dose as patient radiation dose is discussed. Furthermore, advances in real-time patient radiation dose estimation during FGI are considered. Patient dosimetry in FGI, particularly in real time, remains an ongoing challenge. The increasing occurrence and sophistication of these procedures calls for further advances in the field of patient radiation dose monitoring. Improved measuring techniques will aid clinicians in better predicting and managing radiation induced injury following FGI, thus improving patient care. (paper)

  8. Patient dose measurements in fluoroscopic examinations, aiming to the establishment of reference levels in Brazil

    International Nuclear Information System (INIS)

    Canevaro, L.; Drexler, G.

    2001-01-01

    This work was performed to investigate the actual exposure levels of the patients submitted to fluoroscopic procedures in diagnostic radiology. The data will be useful for a baseline in the establishment of local reference levels for fluoroscopic procedures, as recommended by the European Commission and IAEA. At present time there are no internationally accepted definitions for references levels for fluoroscopic complex procedures. Dose-area product (DAP) meters were employed in a pilot survey expressing the radiation exposures in terms of this quantity. This class of instrumentation has not yet been employed in Brazil. Parameters recorded were radiographic technique, fluoroscopy time, number of images, fluoroscopic and radiographic field sizes and DAPs. For fluoroscopy practice, a reference parameters set is recommended, instead of one diagnostic reference level. High patient exposures were found, calling for joined actions of health authorities, physicians, medical physicists, technicians and manufacturers. Monitoring of patient exposure, optimizing the radiation protection and establishing quantitative assessments of the exposition to the population in Brazil in this kind of procedure is important. (author)

  9. Quality assurance in diagnostic radiology - assessing the fluoroscopic image quality

    International Nuclear Information System (INIS)

    Tabakov, S.

    1995-01-01

    The X-ray fluoroscopic image has a considerably lower resolution than the radiographic one. This requires a careful quality control aiming at optimal use of the fluoroscopic equipment. The basic procedures for image quality assessment of Image Intensifier/TV image are described. Test objects from Leeds University (UK) are used as prototypes. The results from examining 50 various fluoroscopic devices are shown. Their limiting spatial resolution varies between 0.8 lp/mm (at maximum II field size) and 2.24 lp/mm (at minimum field size). The mean value of the limiting spatial resolution for a 23 cm Image Intensifier is about 1.24 lp/mm. The mean limits of variation of the contrast/detail diagram for various fluoroscopic equipment are graphically expressed. 14 refs., 1 fig. (author)

  10. Eye lens dosimetry for fluoroscopically guided clinical procedures: practical approaches to protection and dose monitoring

    International Nuclear Information System (INIS)

    Martin, Colin J.

    2016-01-01

    Doses to the eye lenses of clinicians undertaking fluoroscopically guided procedures can exceed the dose annual limit of 20 mSv, so optimisation of radiation protection is essential. Ceiling-suspended shields and disposable radiation absorbing pads can reduce eye dose by factors of 2-7. Lead glasses that shield against exposures from the side can lower doses by 2.5-4.5 times. Training in effective use of protective devices is an essential element in achieving good protection and acceptable eye doses. Effective methods for dose monitoring are required to identify protection issues. Dosemeters worn adjacent to the eye provide the better option for interventional clinicians, but an unprotected dosemeter worn at the neck will give an indication of eye dose that is adequate for most interventional staff. Potential requirements for protective devices and dose monitoring can be determined from risk assessments using generic values for dose linked to examination workload. (author)

  11. Patient doses from fluoroscopically guided cardiac procedures in pediatrics

    Science.gov (United States)

    Martinez, L. C.; Vano, E.; Gutierrez, F.; Rodriguez, C.; Gilarranz, R.; Manzanas, M. J.

    2007-08-01

    Infants and children are a higher risk population for radiation cancer induction compared to adults. Although some values on pediatric patient doses for cardiac procedures have been reported, data to determine reference levels are scarce, especially when compared to those available for adults in diagnostic and therapeutic procedures. The aim of this study is to make a new contribution to the scarce published data in pediatric cardiac procedures and help in the determination of future dose reference levels. This paper presents a set of patient dose values, in terms of air kerma area product (KAP) and entrance surface air kerma (ESAK), measured in a pediatric cardiac catheterization laboratory equipped with a biplane x-ray system with dynamic flat panel detectors. Cardiologists were properly trained in radiation protection. The study includes 137 patients aged between 10 days and 16 years who underwent diagnostic catheterizations or therapeutic procedures. Demographic data and technical details of the procedures were also gathered. The x-ray system was submitted to a quality control programme, including the calibration of the transmission ionization chamber. The age distribution of the patients was 47 for <1 year; 52 for 1-<5 years; 25 for 5-<10 years and 13 for 10-<16 years. Median values of KAP were 1.9, 2.9, 4.5 and 15.4 Gy cm2 respectively for the four age bands. These KAP values increase by a factor of 8 when moving through the four age bands. The probability of a fatal cancer per fluoroscopically guided cardiac procedure is about 0.07%. Median values of ESAK for the four age bands were 46, 50, 56 and 163 mGy, which lie far below the threshold for deterministic effects on the skin. These dose values are lower than those published in previous papers.

  12. Patient doses from fluoroscopically guided cardiac procedures in pediatrics

    International Nuclear Information System (INIS)

    Martinez, L C; Vano, E; Gutierrez, F; Rodriguez, C; Gilarranz, R; Manzanas, M J

    2007-01-01

    Infants and children are a higher risk population for radiation cancer induction compared to adults. Although some values on pediatric patient doses for cardiac procedures have been reported, data to determine reference levels are scarce, especially when compared to those available for adults in diagnostic and therapeutic procedures. The aim of this study is to make a new contribution to the scarce published data in pediatric cardiac procedures and help in the determination of future dose reference levels. This paper presents a set of patient dose values, in terms of air kerma area product (KAP) and entrance surface air kerma (ESAK), measured in a pediatric cardiac catheterization laboratory equipped with a biplane x-ray system with dynamic flat panel detectors. Cardiologists were properly trained in radiation protection. The study includes 137 patients aged between 10 days and 16 years who underwent diagnostic catheterizations or therapeutic procedures. Demographic data and technical details of the procedures were also gathered. The x-ray system was submitted to a quality control programme, including the calibration of the transmission ionization chamber. The age distribution of the patients was 47 for 2 respectively for the four age bands. These KAP values increase by a factor of 8 when moving through the four age bands. The probability of a fatal cancer per fluoroscopically guided cardiac procedure is about 0.07%. Median values of ESAK for the four age bands were 46, 50, 56 and 163 mGy, which lie far below the threshold for deterministic effects on the skin. These dose values are lower than those published in previous papers

  13. Patient radiation dose audits for fluoroscopically guided interventional procedures

    International Nuclear Information System (INIS)

    Balter, Stephen; Rosenstein, Marvin; Miller, Donald L.; Schueler, Beth; Spelic, David

    2011-01-01

    Purpose: Quality management for any use of medical x-ray imaging should include monitoring of radiation dose. Fluoroscopically guided interventional (FGI) procedures are inherently clinically variable and have the potential for inducing deterministic injuries in patients. The use of a conventional diagnostic reference level is not appropriate for FGI procedures. A similar but more detailed quality process for management of radiation dose in FGI procedures is described. Methods: A method that takes into account both the inherent variability of FGI procedures and the risk of deterministic injuries from these procedures is suggested. The substantial radiation dose level (SRDL) is an absolute action level (with regard to patient follow-up) below which skin injury is highly unlikely and above which skin injury is possible. The quality process for FGI procedures collects data from all instances of a given procedure from a number of facilities into an advisory data set (ADS). An individual facility collects a facility data set (FDS) comprised of all instances of the same procedure at that facility. The individual FDS is then compared to the multifacility ADS with regard to the overall shape of the dose distributions and the percent of instances in both the ADS and the FDS that exceed the SRDL. Results: Samples of an ADS and FDS for percutaneous coronary intervention, using the dose metric of reference air kerma (K a,r ) (i.e., the cumulative air kerma at the reference point), are used to illustrate the proposed quality process for FGI procedures. Investigation is warranted whenever the FDS is noticeably different from the ADS for the specific FGI procedure and particularly in two circumstances: (1) When the facility's local median K a,r exceeds the 75th percentile of the ADS and (2) when the percent of instances where K a,r exceeds the facility-selected SRDL is greater for the FDS than for the ADS. Conclusions: Analysis of the two data sets (ADS and FDS) and of the

  14. Video dosimetry: evaluation of X-radiation dose by video fluoroscopic image

    International Nuclear Information System (INIS)

    Nova, Joao Luiz Leocadio da; Lopes, Ricardo Tadeu

    1996-01-01

    A new methodology to evaluate the entrance surface dose on patients under radiodiagnosis is presented. A phantom is used in video fluoroscopic procedures in on line video signal system. The images are obtained from a Siemens Polymat 50 and are digitalized. The results show that the entrance surface dose can be obtained in real time from video imaging

  15. Radiation dose to the operator during fluoroscopically guided spine procedures

    Energy Technology Data Exchange (ETDEWEB)

    Roccatagliata, Luca; Pravata, Emanuele; Cianfoni, Alessandro [Department of Neuroradiology, Neurocenter of Southern Switzerland, Ospedale Regionale di Lugano, Lugano (Switzerland); Presilla, Stefano [Unita di Fisica Medica, Ente Ospedaliero Cantonale (EOC), Bellinzona (Switzerland)

    2017-09-15

    Fluoroscopy is widely used to guide diagnostic and therapeutic spine procedures. The purpose of this study was to quantify radiation incident on the operator (operator Air Kerma) during a wide range of fluoroscopy-guided spine procedures and its correlation with the amount of radiation incident on the patient (Kerma Area Product - KAP). We retrospectively included 57 consecutive fluoroscopically guided spine procedures. KAP [Gy cm{sup 2}] and total fluoroscopy time were recorded for each procedure. An electronic dosimeter recorded the operator Air Kerma [μGy] for each procedure. Operator Air Kerma for each procedure, correlation between KAP and operator Air Kerma, and between KAP and fluoroscopy time was obtained. Operator Air Kerma was widely variable across procedures, with median value of 6.4 μGy per procedure. Median fluoroscopy time and median KAP per procedure were 2.6 min and 4.7 Gy cm{sup 2}, respectively. There was correlation between operator Air Kerma and KAP (r{sup 2} = 0.60), with a slope of 1.6 μGy Air Kerma per unit Gy cm{sup 2} KAP incident on the patient and between fluoroscopy time and KAP (r{sup 2} = 0.63). Operator Air Kerma during individual fluoroscopy-guided spine procedures can be approximated from the commonly and readily available information of the total amount of radiation incident on the patient, measured as KAP. (orig.)

  16. Development of a method to calculate organ doses for the upper gastrointestinal fluoroscopic examination

    International Nuclear Information System (INIS)

    Suleiman, O.H.

    1989-01-01

    A method was developed to quantitatively measure the upper gastrointestinal fluoroscopic examination in order to calculate organ doses. The dynamic examination was approximated with a set of discrete x-ray fields. Once the examination was segmented into discrete x-ray fields appropriate organ dose tables were generated using an existing computer program for organ dose calculations. This, along with knowledge of the radiation exposures associated with each of the fields, enabled the calculation of organ doses for the entire dynamic examination. The protocol involves videotaping the examination while fluoroscopic technique factors, tube current and tube potential, are simultaneously recorded on the audio tracks of the videotape. Subsequent analysis allows the dynamic examination to be segmented into a series of discrete x-ray fields uniquely defined by field size, projection, and anatomical region. The anatomical regions associated with the upper gastrointestinal examination were observed to be the upper, middle, and lower esophagus, the gastroesophageal junction, the stomach, and the duodenum

  17. Edge enhancement algorithm for low-dose X-ray fluoroscopic imaging.

    Science.gov (United States)

    Lee, Min Seok; Park, Chul Hee; Kang, Moon Gi

    2017-12-01

    Low-dose X-ray fluoroscopy has continually evolved to reduce radiation risk to patients during clinical diagnosis and surgery. However, the reduction in dose exposure causes quality degradation of the acquired images. In general, an X-ray device has a time-average pre-processor to remove the generated quantum noise. However, this pre-processor causes blurring and artifacts within the moving edge regions, and noise remains in the image. During high-pass filtering (HPF) to enhance edge detail, this noise in the image is amplified. In this study, a 2D edge enhancement algorithm comprising region adaptive HPF with the transient improvement (TI) method, as well as artifacts and noise reduction (ANR), was developed for degraded X-ray fluoroscopic images. The proposed method was applied in a static scene pre-processed by a low-dose X-ray fluoroscopy device. First, the sharpness of the X-ray image was improved using region adaptive HPF with the TI method, which facilitates sharpening of edge details without overshoot problems. Then, an ANR filter that uses an edge directional kernel was developed to remove the artifacts and noise that can occur during sharpening, while preserving edge details. The quantitative and qualitative results obtained by applying the developed method to low-dose X-ray fluoroscopic images and visually and numerically comparing the final images with images improved using conventional edge enhancement techniques indicate that the proposed method outperforms existing edge enhancement methods in terms of objective criteria and subjective visual perception of the actual X-ray fluoroscopic image. The developed edge enhancement algorithm performed well when applied to actual low-dose X-ray fluoroscopic images, not only by improving the sharpness, but also by removing artifacts and noise, including overshoot. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Radiofrequency catheter ablation: Relationship between fluoroscopic time and skin doses according to diagnoses. Basis to establish a quality assurance programme

    International Nuclear Information System (INIS)

    Cotelo, E.; Pouso, J.; Reyes, W.

    2001-01-01

    Radiofrequency Cardiac Catheter Ablation is an Interventional Radiology procedure of great complexity because the cardiologist needs a simultaneous evaluation of fluoroscopic images and electrophysiologic information. Therefore, the procedure typically involves extended fluoroscopic time that may cause radiation-skin injures to patients. Skin doses depend on many factors: equipment design features and its proper use, cardiologist practice, fluoroscopic time, irradiated areas, application of radiation protection recommendations, etc. We evaluate fluoroscopic time in relation to pathology and we estimate skin doses on 233 procedures at the Electrophysiology Laboratory in Casa de Galicia, Montevideo, Uruguay. Significant differences among the medians of fluoroscopic time were found in those procedures depending on diagnoses and results. Higher fluoroscopic time was found in flutter and auricular tachycardia (median was 83 minutes, p=0.0001). In successful procedures (almost 90%), median skin doses was 2.0 Grays (p=0.0001). On the basis of records information, the standard operating procedure and the clinical protocol, expanding close cooperation between the cardiologists and the experts in Radiation Protection will secure the establishment of an Assurance Quality Program. (author)

  19. MO-F-CAMPUS-I-02: Occupational Conceptus Doses From Fluoroscopically-Guided Interventional Procedures

    Energy Technology Data Exchange (ETDEWEB)

    Damilakis, J; Perisinakis, K; Solomou, G [University of Crete (Greece); Stratakis, J [University of Crete, Heraklion, Crete (Greece)

    2015-06-15

    Purpose: The aim of this method was to provide dosimetric data on conceptus dose for the pregnant employee who participates in fluoroscopically-guided interventional procedures. Methods: Scattered air-kerma dose rates were obtained for 17 fluoroscopic projections involved in interventional procedures. These projections were simulated on an anthropomorphic phantom placed on the examination table supine. The operating theater was divided into two grids relative to the long table sides. Each grid consisted of 33 cells spaced 0.50 m apart. During the simulated exposures, at each cell, scatter air-kerma rate was measured at 110 cm from the floor i.e. at the height of the waist of the pregnant worker. Air-kerma rates were divided by the dose area product (DAP) rate of each exposure to obtain normalized data. For each projection, measurements were performed for 3 kVp and 3 filtration values i.e. for 9 different x-ray spectra. All measurements were performed by using a modern C-arm angiographic system (Siemens Axiom Artis, Siemens, Germany) and a radiation meter equipped with an ionization chamber. Results: The results consist of 153 iso-dose maps, which show the spatial distribution of DAP-normalized scattered air-kerma doses at the waist level of a pregnant worker. Conceptus dose estimation is possible using air-kerma to embryo/fetal dose conversion coefficients published in a previous study (J Cardiovasc Electrophysiol, Vol. 16, pp. 1–8, July 2005). Using these maps, occupationally exposed pregnant personnel may select a working position for a certain projection that keeps abdominal dose as low as reasonably achievable. Taking into consideration the regulatory conceptus dose limit for occupational exposure, determination of the maximum workload allowed for the pregnant personnel is also possible. Conclusion: Data produced in this work allow for the anticipation of conceptus dose and the determination of the maximum workload for a pregnant worker from any

  20. MO-F-CAMPUS-I-02: Occupational Conceptus Doses From Fluoroscopically-Guided Interventional Procedures

    International Nuclear Information System (INIS)

    Damilakis, J; Perisinakis, K; Solomou, G; Stratakis, J

    2015-01-01

    Purpose: The aim of this method was to provide dosimetric data on conceptus dose for the pregnant employee who participates in fluoroscopically-guided interventional procedures. Methods: Scattered air-kerma dose rates were obtained for 17 fluoroscopic projections involved in interventional procedures. These projections were simulated on an anthropomorphic phantom placed on the examination table supine. The operating theater was divided into two grids relative to the long table sides. Each grid consisted of 33 cells spaced 0.50 m apart. During the simulated exposures, at each cell, scatter air-kerma rate was measured at 110 cm from the floor i.e. at the height of the waist of the pregnant worker. Air-kerma rates were divided by the dose area product (DAP) rate of each exposure to obtain normalized data. For each projection, measurements were performed for 3 kVp and 3 filtration values i.e. for 9 different x-ray spectra. All measurements were performed by using a modern C-arm angiographic system (Siemens Axiom Artis, Siemens, Germany) and a radiation meter equipped with an ionization chamber. Results: The results consist of 153 iso-dose maps, which show the spatial distribution of DAP-normalized scattered air-kerma doses at the waist level of a pregnant worker. Conceptus dose estimation is possible using air-kerma to embryo/fetal dose conversion coefficients published in a previous study (J Cardiovasc Electrophysiol, Vol. 16, pp. 1–8, July 2005). Using these maps, occupationally exposed pregnant personnel may select a working position for a certain projection that keeps abdominal dose as low as reasonably achievable. Taking into consideration the regulatory conceptus dose limit for occupational exposure, determination of the maximum workload allowed for the pregnant personnel is also possible. Conclusion: Data produced in this work allow for the anticipation of conceptus dose and the determination of the maximum workload for a pregnant worker from any

  1. The child fluoroscopic examination in the I.I.-DR. Reduction of radiation exposure dose

    International Nuclear Information System (INIS)

    Endo, Takayuki

    2001-01-01

    This examination for I.I.-DR conditions was done for the purpose of reducing radiation exposure dose in child gastrointestinal fluoroscopy. Fluoroscopic apparatus used was Toshiba MAX-1000A with imaging recorder DDX-1000A. Dose was measured with a thimble ionization chamber Radcal Corporation Model 9015. Examinations for conditions were performed with the standard dose determined, the digital value 300, giving the plateau contrast ratio of acryl plate/barium sulfate. Reduction to about 10% dose (57 μGy/min for pulse fluoroscopy and 6.8 μGy/film for filming) relative to the usual method (764 μGy/min and 36.0 μGy/film, respectively) was found attained with additional filter of Al 0.5 mm + Cu 0.2 mm and IRIS diameter 100 with acryl thickness of 10 cm. Actual images of 6 months old baby were presented. (K.H.)

  2. Pediatric patient and staff dose measurements in barium meal fluoroscopic procedures

    Science.gov (United States)

    Filipov, D.; Schelin, H. R.; Denyak, V.; Paschuk, S. A.; Porto, L. E.; Ledesma, J. A.; Nascimento, E. X.; Legnani, A.; Andrade, M. E. A.; Khoury, H. J.

    2015-11-01

    This study investigates patient and staff dose measurements in pediatric barium meal series fluoroscopic procedures. It aims to analyze radiographic techniques, measure the air kerma-area product (PKA), and estimate the staff's eye lens, thyroid and hands equivalent doses. The procedures of 41 patients were studied, and PKA values were calculated using LiF:Mg,Ti thermoluminescent dosimeters (TLDs) positioned at the center of the patient's upper chest. Furthermore, LiF:Mg,Cu,P TLDs were used to estimate the equivalent doses. The results showed a discrepancy in the radiographic techniques when compared to the European Commission recommendations. Half of the results of the analyzed literature presented lower PKA and dose reference level values than the present study. The staff's equivalent doses strongly depends on the distance from the beam. A 55-cm distance can be considered satisfactory. However, a distance decrease of ~20% leads to, at least, two times higher equivalent doses. For eye lenses this dose is significantly greater than the annual limit set by the International Commission on Radiological Protection. In addition, the occupational doses were found to be much higher than in the literature. Changing the used radiographic techniques to the ones recommended by the European Communities, it is expected to achieve lower PKA values ​​and occupational doses.

  3. Estimation of breast doses and breast cancer risk associated with repeated fluoroscopic chest examinations of women with tuberculosis

    International Nuclear Information System (INIS)

    Boice, J.D. Jr.; Rosenstein, M.; Trout, E.D.

    1978-01-01

    A methodology is presented to estimate cumulative breast dose and breast cancer risk for women exposed to repeated fluoroscopic chest examinations during air collapse therapy for pulmonary tuberculosis. Medical record abstraction, physician interview, patient contact, machine exposure measurements, and absorbed dose computations were combined to estimate average breast doses for 1047 Massachusetts women who were treated between 1930 and 1954. The methodology presented considers breast size and composition, patient orientation, x-ray field size and location, beam quality, type of examination, machine exposure rate, and exposure time during fluoroscopic examinations. The best estimate for the risk of radiation-induced cancer for the women living longer than 10 years after initial fluoroscopic exposure is 6.2 excess breast cancers per million woman-year-rad with 90% confidence limits of 2.8 and 10.7 cancers/10 6 WY-rad. When breast cancer risk is considered as a function of absorbed dose in the breast, instead of as a function of the number of fluoroscopic examinations, a linear dose--response relationship over the range of estimated doses is consistent with the data. However, because of the uncertainty due to small-sample variability and because of the wide range of assumptions regarding certain fluoroscopy conditions, other dose--response relationships are compatible with the data

  4. SU-D-209-02: Percent Depth Dose Curves for Fluoroscopic X-Ray Beam Qualities Incorporating Copper Filtration

    Energy Technology Data Exchange (ETDEWEB)

    Wunderle, K [Cleveland Clinic Foundation, Cleveland, OH (United States); Wayne State University School of Medicine, Detroit, MI (United States); Godley, A; Shen, Z; Dong, F [Cleveland Clinic Foundation, Cleveland, OH (United States); Rakowski, J [Wayne State University School of Medicine, Detroit, MI (United States)

    2016-06-15

    Purpose: The purpose of this investigation was to quantify percent depth dose (PDD) curves for fluoroscopic x-ray beam qualities incorporating added copper filtration. Methods: A PTW (Freiburg, Germany) MP3 water tank was used with a Standard Imaging (Middleton, WI) Exradin Model 11 Spokas Chamber to measure PDD curves for 60, 80, 100 and 120 kVp x-ray beams with copper filtration ranging from 0.0–0.9 mm at 22cm and 42cm fields of view from 0 to 150 mm of water. A free-in-air monitor chamber was used to normalize the water tank data to fluctuations in output from the fluoroscope. The measurements were acquired on a Siemens (Erlangen, Germany) Artis ZeeGo fluoroscope. The fluoroscope was inverted from the typical orientation providing an x-ray beam originating from above the water tank. The water tank was positioned so that the water level was located at 60cm from the focal spot; which also represents the focal spot to interventional reference plane distance for that fluoroscope. Results: PDDs for 60, 80, 100, and 120 kVp with 0 mm of copper filtration compared well to previously published data by Fetterly et al. [Med Phys, 28, 205 (2001)] for those beam qualities given differences in fluoroscopes, geometric orientation, type of ionization chamber, and the water tank used for data collection. PDDs for 60, 80, 100, and 120 kVp with copper filtration were obtained and are presented, which have not been previously investigated and published. Conclusion: The equipment and processes used to acquire the reported data were sound and compared well with previously published data for PDDs without copper filtration. PDD data for the fluoroscopic x-ray beams incorporating copper filtration can be used as reference data for estimating organ or soft tissue dose at depth involving similar beam qualities or for comparison with mathematical models.

  5. Patient and staff doses and relationships between them in fluoroscopically guided procedures

    International Nuclear Information System (INIS)

    Avramova-Cholakova, S.; Christova-Popova, Y.; Sagorska, A.

    2015-01-01

    Full text: Medical exposure has the main contribution to man-made sources of exposures to the population in developed countries. Fluoroscopically guided procedures in interventional cardiology, gastroenterology, urology, orthopaedics and others may be related to high doses to both patients and staff. The main risk for both groups is the radiation carcinogenesis and it is increasing with dose. However deterministic effects are also possible: severe patient skin injuries occur sometimes. There are such cases in Bulgarian radiological practice. For the medical staff, involved in the procedures, radiation induced cataract is observed occasionally. Learning objective: In many cases there is direct correlation between patient and staff doses. Several simple rules must be observed in order to decrease exposure. Rules related to patient: Patient dose (dose-area product (DAP), fluoroscopy time, number of series,number of images) should be recorded for every patient; The patient should be positioned as far away as possible from the x-ray tube and as closer as possible to the image intensifier/digital image receptor; Fluoroscopy time should be minimized; Pulsed fluoroscopy with the lowest dose rate and the lowest frame rate providing acceptable image quality should be used; Different skin areas should be exposed in different projections; Oblique projections increase the dose - they should be avoided; Magnification also increases the dose several times and should be avoided; The acquisition mode should be avoided; it delivers dozens of times higher doses. Minimal number of frames and cine runs should be used. Use of “last image hold” is encouraged; The x-ray beam should be collimated to the area of interest. Rules related to staff: The staff receives scattered radiation from patient’s body. Every measure to decrease patient’s dose decreases staff dose as well; Every available protective device should be used (lead apron, thyroid collar, lead glasses, screens). They

  6. Relationship between source-surface distance and patient dose in fluoroscopic X-ray examinations

    International Nuclear Information System (INIS)

    Suzuki, Shoichi; Asada, Yasuki; Nishi, Kazuta; Mizuno, Emiko; Hara, Natsue; Orito, Takeo; Kamei, Tetsuya; Koga, Sukehiko

    2000-01-01

    The International Electrotechnical Commission, IEC provided in its standard IEC 60601-1-3 (1994) to prevent the use during radioscopic irradiation of focal spot to skin distances less than 20 cm if the X-RAY EQUIPMENT is specified for RADIOSCOPY during surgery or 30 cm for other specified applications. This standard was reflected in the Japanese Industrial Standard JIS Z 4701-1997, which provided the minimum distance from focal spot to skin to be 30 cm for the use of a fluoroscopic and radiographic table (Under-table type). However, JIS had formerly provided the minimum distance to be 40 cm and so does the current Medical Treatment Law. The draft revision for the Medical Treatment Law currently discussed has consideration to adopt the value 30 cm in accordance with the current JIS. Our research intended to investigate the impact on the entrance surface dose for the change of the focal spot to skin distance from 40 cm to 30 cm. The result was 20-30% increase of the entrance surface dose for the focal spot to skin distance 30 cm. Taking patient exposure dose into account, we need further and more sufficient discussion with this result before adopting this value to the Medical Treatment Law. (author)

  7. Patient and staff doses in fluoroscopically guided invasive diagnostic and interventional urology procedures

    International Nuclear Information System (INIS)

    Ivanova, D.; Hristova-Popova, J.; Avramova-Cholakova, S.; Deyanova, Ts.; Dobrikov, R.

    2015-01-01

    Full text: The aim of this study is to evaluate patient and staff doses in fluoroscopically guided invasive diagnostic and interventional urology procedures. All the data were collected in the Emergency Hospital 'N. I. Pirogov'. While recording data for the patients, a real time dosimetry measurement of the medical staff was made. Air kerma-area product (KAP) was recorded for intravenous pyelogram (IVP), percutaneous nephrostomy (PN) and ureteral 'double-J' stenting. Patient data sex, age and weight were also taken. Staff doses were estimated with the system RaySafe i2. It contains four dosimeters, with a wireless connection to a real time display. The dosimeters were worn on the unprotected upper part of the body and measured the personal dose equivalent Hp(10). The mean KAP values for the procedures are: 3.21 Gy.cm 2 for IVP, 10.37 Gy.cm 2 for PN and 4.15 Gy.cm 2 for 'double-J' respectively. The highest staff dose for PN and 'double-J' is received by the urologist (160 μSv and 47.3 μSv, respectively), while for the IVP the radiographer has the highest exposure (20 μSv). Each member of the medical staff was on a different position in respect to the X-ray tube and the patient, which is the main reason for the differences in the staff doses. The variations in the mean patient and staff doses are mostly due to the interventions themselves, their complexity and the individual treatment of every patient. RaySafe i2 is very useful as guideline for making a choice of a better position and in the decreasing of radiation exposure to the staff

  8. Estimation of entrance dose during selected fluoroscopic examinations in some hospitals in Khartoum state

    International Nuclear Information System (INIS)

    Mohammed, Heba Abdalkareem Osman

    2016-01-01

    A diagnostic fluoroscopy is a modality that involves visualizing the anatomy using radiation in real time. Therefore, patients doses have a potential for being great, increasing the chance of the radiation induced carcinogenesis. The objective of this study was to determine the mean entrance surface dose (ESD) from selected fluoroscopic examinations namely, hysterosalpingography (HSG) and ascendingurethogram (ASU) in three hospitals in Khartoum State. A total of 87 and 110 patents for HSG and ASU respectively were examined. The data were collected over four months. The mean ESD for patients who underwent HSG were 16.2 mGy, 20.6 mGy and 25.9 mGY respectively, while the ESD for patient who underwent ascendingurethrogram for AP view were 3.5mGy, 2.9mGy and 11.9mGy and for OB view 15.9 mGy, 18.3 mGy and 25.4 mGy. Patient doses were calculated using mathematical equation and the results were compared with the ESDs calculated using mathematical equation and the results were found to be comparable with the ESDs reported in previous studies and within the guidance level established by the ICRP. Fluoroscopy time, operator skills, x-ray machine type and clinical complexity of the procedures were shown to be major contributors to the variations reported in the measured ESDs. The study demonstrated the need for standardization of techniques throughout the hospitals and suggested that there ia a need to optimize the procedures.(Author)

  9. Evaluation of methods to produce an image library for automatic patient model localization for dose mapping during fluoroscopically guided procedures

    Science.gov (United States)

    Kilian-Meneghin, Josh; Xiong, Z.; Rudin, S.; Oines, A.; Bednarek, D. R.

    2017-03-01

    The purpose of this work is to evaluate methods for producing a library of 2D-radiographic images to be correlated to clinical images obtained during a fluoroscopically-guided procedure for automated patient-model localization. The localization algorithm will be used to improve the accuracy of the skin-dose map superimposed on the 3D patient- model of the real-time Dose-Tracking-System (DTS). For the library, 2D images were generated from CT datasets of the SK-150 anthropomorphic phantom using two methods: Schmid's 3D-visualization tool and Plastimatch's digitally-reconstructed-radiograph (DRR) code. Those images, as well as a standard 2D-radiographic image, were correlated to a 2D-fluoroscopic image of a phantom, which represented the clinical-fluoroscopic image, using the Corr2 function in Matlab. The Corr2 function takes two images and outputs the relative correlation between them, which is fed into the localization algorithm. Higher correlation means better alignment of the 3D patient-model with the patient image. In this instance, it was determined that the localization algorithm will succeed when Corr2 returns a correlation of at least 50%. The 3D-visualization tool images returned 55-80% correlation relative to the fluoroscopic-image, which was comparable to the correlation for the radiograph. The DRR images returned 61-90% correlation, again comparable to the radiograph. Both methods prove to be sufficient for the localization algorithm and can be produced quickly; however, the DRR method produces more accurate grey-levels. Using the DRR code, a library at varying angles can be produced for the localization algorithm.

  10. Scattered radiation dose to radiologist's cornea, thyroid and gonads while performing some x-ray fluoroscopic investigations

    International Nuclear Information System (INIS)

    Chougle, Arun

    1993-01-01

    The mankind has been immensely benefited from discovery of X-ray and it has found wide spread application in diagnosis and treatment. Radiation is harmful and can produce somatic and genetic effects in the exposed person. International Commission on Radiation Protection (ICRP) has recommended a system of dose limitation based on principle of ALARA. All the efforts should be made to keep the radiation dose to the radiation worker as low as possible. Fluoroscopy gives maximum dose to the patient and staff and hence we have attempted to quantify the scattered radiation dose to the cornea, thyroid and gonads of the radiologist performing fluoroscopic examinations such as barium meal, barium swallow, barium enema, myelography, histerosalpingography and fracture reduction. Thermoluminescence dosimetry (TLD) method using CaSO 4 :Dy TLD disc was employed for these measurements. Use of lead apron has reduced the dose to radiologist's gonad. (author). 3 refs., 4 tabs

  11. Fluoroscopic dose reduction by acquisition frame rate reduction and image processing

    International Nuclear Information System (INIS)

    Fritz, S.L.; Mirvis, S.E.; Pals, S.O.

    1986-01-01

    A new design for fluoroscopic exposure reduction incorporates pulsed x-ray exposure, progressive scan video acquisition at frame rates below 30 Hz, interlaced video display at 30 Hz, and a video rate image processing. To evaluate this design, a variety of phantom systems have been developed to measure the impact of low frame rate pulsed digital fluoroscopy on the performance of several clinical tasks (e.g., catheter placement). The authors are currently using these phantoms with a digital fluoroscopy system using continuous x-ray, interlaced video acquisition and variable acquisition frame rate. The design of their target digital fluoroscopic system, sample image sequences, and the results of some preliminary phantom studies are reported

  12. TU-D-209-03: Alignment of the Patient Graphic Model Using Fluoroscopic Images for Skin Dose Mapping

    Energy Technology Data Exchange (ETDEWEB)

    Oines, A; Oines, A; Kilian-Meneghin, J; Karthikeyan, B; Rudin, S; Bednarek, D [University at Buffalo (SUNY) School of Med., Buffalo, NY (United States)

    2016-06-15

    Purpose: The Dose Tracking System (DTS) was developed to provide realtime feedback of skin dose and dose rate during interventional fluoroscopic procedures. A color map on a 3D graphic of the patient represents the cumulative dose distribution on the skin. Automated image correlation algorithms are described which use the fluoroscopic procedure images to align and scale the patient graphic for more accurate dose mapping. Methods: Currently, the DTS employs manual patient graphic selection and alignment. To improve the accuracy of dose mapping and automate the software, various methods are explored to extract information about the beam location and patient morphology from the procedure images. To match patient anatomy with a reference projection image, preprocessing is first used, including edge enhancement, edge detection, and contour detection. Template matching algorithms from OpenCV are then employed to find the location of the beam. Once a match is found, the reference graphic is scaled and rotated to fit the patient, using image registration correlation functions in Matlab. The algorithm runs correlation functions for all points and maps all correlation confidences to a surface map. The highest point of correlation is used for alignment and scaling. The transformation data is saved for later model scaling. Results: Anatomic recognition is used to find matching features between model and image and image registration correlation provides for alignment and scaling at any rotation angle with less than onesecond runtime, and at noise levels in excess of 150% of those found in normal procedures. Conclusion: The algorithm provides the necessary scaling and alignment tools to improve the accuracy of dose distribution mapping on the patient graphic with the DTS. Partial support from NIH Grant R01-EB002873 and Toshiba Medical Systems Corp.

  13. TU-D-209-03: Alignment of the Patient Graphic Model Using Fluoroscopic Images for Skin Dose Mapping

    International Nuclear Information System (INIS)

    Oines, A; Oines, A; Kilian-Meneghin, J; Karthikeyan, B; Rudin, S; Bednarek, D

    2016-01-01

    Purpose: The Dose Tracking System (DTS) was developed to provide realtime feedback of skin dose and dose rate during interventional fluoroscopic procedures. A color map on a 3D graphic of the patient represents the cumulative dose distribution on the skin. Automated image correlation algorithms are described which use the fluoroscopic procedure images to align and scale the patient graphic for more accurate dose mapping. Methods: Currently, the DTS employs manual patient graphic selection and alignment. To improve the accuracy of dose mapping and automate the software, various methods are explored to extract information about the beam location and patient morphology from the procedure images. To match patient anatomy with a reference projection image, preprocessing is first used, including edge enhancement, edge detection, and contour detection. Template matching algorithms from OpenCV are then employed to find the location of the beam. Once a match is found, the reference graphic is scaled and rotated to fit the patient, using image registration correlation functions in Matlab. The algorithm runs correlation functions for all points and maps all correlation confidences to a surface map. The highest point of correlation is used for alignment and scaling. The transformation data is saved for later model scaling. Results: Anatomic recognition is used to find matching features between model and image and image registration correlation provides for alignment and scaling at any rotation angle with less than onesecond runtime, and at noise levels in excess of 150% of those found in normal procedures. Conclusion: The algorithm provides the necessary scaling and alignment tools to improve the accuracy of dose distribution mapping on the patient graphic with the DTS. Partial support from NIH Grant R01-EB002873 and Toshiba Medical Systems Corp.

  14. Patient Dose Optimization in Fluoroscopically Guided Interventional Procedures. Final Report of a Coordinated Research Project

    International Nuclear Information System (INIS)

    2010-01-01

    In recent years, many surgical procedures have increasingly been replaced by interventional procedures that guide catheters into the arteries under X ray fluoroscopic guidance to perform a variety of operations such as ballooning, embolization, implantation of stents etc. The radiation exposure to patients and staff in such procedures is much higher than in simple radiographic examinations like X ray of chest or abdomen such that radiation induced skin injuries to patients and eye lens opacities among workers have been reported in the 1990's and after. Interventional procedures have grown both in frequency and importance during the last decade. This Coordinated Research Project (CRP) and TECDOC were developed within the International Atomic Energy Agency's (IAEA) framework of statutory responsibility to provide for the worldwide application of the standards for the protection of people against exposure to ionizing radiation. The CRP took place between 2003 and 2005 in six countries, with a view of optimizing the radiation protection of patients undergoing interventional procedures. The Fundamental Safety Principles and the International Basic Safety Standards for Protection against Ionizing Radiation (BSS) issued by the IAEA and co-sponsored by the Food and Agriculture Organization of the United Nations (FAO), the International Labour Organization (ILO), the World Health Organization (WHO), the Pan American Health Organization (PAHO) and the Nuclear Energy Agency (NEA), among others, require the radiation protection of patients undergoing medical exposures through justification of the procedures involved and through optimization. In keeping with its responsibility on the application of standards, the IAEA programme on Radiological Protection of Patients encourages the reduction of patient doses. To facilitate this, it has issued specific advice on the application of the BSS in the field of radiology in Safety Reports Series No. 39 and the three volumes on Radiation

  15. Influence of Flat-Panel Fluoroscopic Equipment Variables on Cardiac Radiation Doses

    International Nuclear Information System (INIS)

    Nickoloff, Edward L.; Lu Zhengfeng; Dutta, Ajoy; So, James; Balter, Stephen; Moses, Jeffrey

    2007-01-01

    Purpose. To assess the influence of physician-selectable equipment variables on the potential radiation dose reductions during cardiac catheterization examinations using modern imaging equipment. Materials. A modern bi-plane angiography unit with flat-panel image receptors was used. Patients were simulated with 15-30 cm of acrylic plastic. The variables studied were: patient thickness, fluoroscopy pulse rates, record mode frame rates, image receptor field-of-view (FoV), automatic dose control (ADC) mode, SID/SSD geometry setting, automatic collimation, automatic positioning, and others. Results. Patient radiation doses double for every additional 3.5-4.5 cm of soft tissue. The dose is directly related to the imaging frame rate; a decrease from 30 pps to 15 pps reduces the dose by about 50%. The dose is related to [(FoV) -N ] where 2.0 < N < 3.0. Suboptimal positioning of the patient can nearly double the dose. The ADC system provides three selections that can vary the radiation level by 50%. For pediatric studies (2-5 years old), the selection of equipment variables can result in entrance radiation doses that range between 6 and 60 cGy for diagnostic cases and between 15 and 140 cGy for interventional cases. For adult studies, the equipment variables can produce entrance radiation doses that range between 13 and 130 cGy for diagnostic cases and between 30 and 400 cGy for interventional cases. Conclusions. Overall dose reductions of 70-90% can be achieved with pediatric patients and about 90% with adult patients solely through optimal selection of equipment variables

  16. Real-Time Verification of a High-Dose-Rate Iridium 192 Source Position Using a Modified C-Arm Fluoroscope

    Energy Technology Data Exchange (ETDEWEB)

    Nose, Takayuki, E-mail: nose-takayuki@nms.ac.jp [Department of Radiation Oncology, Nippon Medical School Tamanagayama Hospital, Tama (Japan); Chatani, Masashi [Department of Radiation Oncology, Osaka Rosai Hospital, Sakai (Japan); Otani, Yuki [Department of Radiology, Kaizuka City Hospital, Kaizuka (Japan); Teshima, Teruki [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Kumita, Shinichirou [Department of Radiology, Nippon Medical School Hospital, Tokyo (Japan)

    2017-03-15

    Purpose: High-dose-rate (HDR) brachytherapy misdeliveries can occur at any institution, and they can cause disastrous results. Even a patient's death has been reported. Misdeliveries could be avoided with real-time verification methods. In 1996, we developed a modified C-arm fluoroscopic verification of an HDR Iridium 192 source position prevent these misdeliveries. This method provided excellent image quality sufficient to detect errors, and it has been in clinical use at our institutions for 20 years. The purpose of the current study is to introduce the mechanisms and validity of our straightforward C-arm fluoroscopic verification method. Methods and Materials: Conventional X-ray fluoroscopic images are degraded by spurious signals and quantum noise from Iridium 192 photons, which make source verification impractical. To improve image quality, we quadrupled the C-arm fluoroscopic X-ray dose per pulse. The pulse rate was reduced by a factor of 4 to keep the average exposure compliant with Japanese medical regulations. The images were then displayed with quarter-frame rates. Results: Sufficient quality was obtained to enable observation of the source position relative to both the applicators and the anatomy. With this method, 2 errors were detected among 2031 treatment sessions for 370 patients within a 6-year period. Conclusions: With the use of a modified C-arm fluoroscopic verification method, treatment errors that were otherwise overlooked were detected in real time. This method should be given consideration for widespread use.

  17. TH-E-209-01: Fluoroscopic Dose Monitoring and Patient Follow-Up Program at Massachusetts General Hospital

    International Nuclear Information System (INIS)

    Liu, B.

    2016-01-01

    Radiation dose monitoring solutions have opened up new opportunities for medical physicists to be more involved in modern clinical radiology practices. In particular, with the help of comprehensive radiation dose data, data-driven protocol management and informed case follow up are now feasible. Significant challenges remain however and the problems faced by medical physicists are highly heterogeneous. Imaging systems from multiple vendors and a wide range of vintages co-exist in the same department and employ data communication protocols that are not fully standardized or implemented making harmonization complex. Many different solutions for radiation dose monitoring have been implemented by imaging facilities over the past few years. Such systems are based on commercial software, home-grown IT solutions, manual PACS data dumping, etc., and diverse pathways can be used to bring the data to impact clinical practice. The speakers will share their experiences with creating or tailoring radiation dose monitoring/management systems and procedures over the past few years, which vary significantly in design and scope. Topics to cover: (1) fluoroscopic dose monitoring and high radiation event handling from a large academic hospital; (2) dose monitoring and protocol optimization in pediatric radiology; and (3) development of a home-grown IT solution and dose data analysis framework. Learning Objectives: Describe the scope and range of radiation dose monitoring and protocol management in a modern radiology practice Review examples of data available from a variety of systems and how it managed and conveyed. Reflect on the role of the physicist in radiation dose awareness.

  18. TH-E-209-01: Fluoroscopic Dose Monitoring and Patient Follow-Up Program at Massachusetts General Hospital

    Energy Technology Data Exchange (ETDEWEB)

    Liu, B. [Massachusetts General Hospital (United States)

    2016-06-15

    Radiation dose monitoring solutions have opened up new opportunities for medical physicists to be more involved in modern clinical radiology practices. In particular, with the help of comprehensive radiation dose data, data-driven protocol management and informed case follow up are now feasible. Significant challenges remain however and the problems faced by medical physicists are highly heterogeneous. Imaging systems from multiple vendors and a wide range of vintages co-exist in the same department and employ data communication protocols that are not fully standardized or implemented making harmonization complex. Many different solutions for radiation dose monitoring have been implemented by imaging facilities over the past few years. Such systems are based on commercial software, home-grown IT solutions, manual PACS data dumping, etc., and diverse pathways can be used to bring the data to impact clinical practice. The speakers will share their experiences with creating or tailoring radiation dose monitoring/management systems and procedures over the past few years, which vary significantly in design and scope. Topics to cover: (1) fluoroscopic dose monitoring and high radiation event handling from a large academic hospital; (2) dose monitoring and protocol optimization in pediatric radiology; and (3) development of a home-grown IT solution and dose data analysis framework. Learning Objectives: Describe the scope and range of radiation dose monitoring and protocol management in a modern radiology practice Review examples of data available from a variety of systems and how it managed and conveyed. Reflect on the role of the physicist in radiation dose awareness.

  19. MO-F-CAMPUS-I-01: A System for Automatically Calculating Organ and Effective Dose for Fluoroscopically-Guided Procedures

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Z; Vijayan, S; Rana, V; Rudin, S; Bednarek, D [Toshiba Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY (United States)

    2015-06-15

    Purpose: A system was developed that automatically calculates the organ and effective dose for individual fluoroscopically-guided procedures using a log of the clinical exposure parameters. Methods: We have previously developed a dose tracking system (DTS) to provide a real-time color-coded 3D- mapping of skin dose. This software produces a log file of all geometry and exposure parameters for every x-ray pulse during a procedure. The data in the log files is input into PCXMC, a Monte Carlo program that calculates organ and effective dose for projections and exposure parameters set by the user. We developed a MATLAB program to read data from the log files produced by the DTS and to automatically generate the definition files in the format used by PCXMC. The processing is done at the end of a procedure after all exposures are completed. Since there are thousands of exposure pulses with various parameters for fluoroscopy, DA and DSA and at various projections, the data for exposures with similar parameters is grouped prior to entry into PCXMC to reduce the number of Monte Carlo calculations that need to be performed. Results: The software developed automatically transfers data from the DTS log file to PCXMC and runs the program for each grouping of exposure pulses. When the dose from all exposure events are calculated, the doses for each organ and all effective doses are summed to obtain procedure totals. For a complicated interventional procedure, the calculations can be completed on a PC without manual intervention in less than 30 minutes depending on the level of data grouping. Conclusion: This system allows organ dose to be calculated for individual procedures for every patient without tedious calculations or data entry so that estimates of stochastic risk can be obtained in addition to the deterministic risk estimate provided by the DTS. Partial support from NIH grant R01EB002873 and Toshiba Medical Systems Corp.

  20. Fluoroscopic digital radiography

    International Nuclear Information System (INIS)

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

    1987-01-01

    The authors have been working with three different developmental systems, exploring the clinical benefits of digital recording of the fluoroscopic image. This educational exhibit describes the components of such systems and emphasizes the strengths and weaknesses of each. Specific technical reference is made to the image intensifier, TV camera, 1,024/sup 2/ image store, hard copy devices, and the mechanics of operation in the general fluoroscopic environment. All observations indicate that the problems of resolution, motion blur, noise, field size, and dose can be solved. The findings are supported by clinical examples

  1. Radiation dose reduction in fluoroscopic procedures: left varicocele embolization as a model

    Energy Technology Data Exchange (ETDEWEB)

    Verstandig, Anthony G.; Shraibman, Vladimir [Shaare Zedek Medical Center, Department of Radiology, Interventional Radiology Unit, POB 3235, Jerusalem (Israel); Shamieh, Bashar [St. Joseph Hospital, Department of Radiology, Jerusalem (Israel); Raveh, David [Shaare Zedek Medical Center, Infectious Diseases Unit, POB 3235, Jerusalem (Israel)

    2015-06-01

    To investigate the effect of a radiation reduction program on total dose, fluoroscopy dose per second corrected for body habitus and degree of collimation in left varicocele embolizations (LVE). A radiation reduction program for LVE was implemented, consisting of a technique minimizing fluoroscopy time, using low-dose presets, virtual collimation, and virtual patient positioning. Height, weight, fluoroscopy time, kerma area product (KAP) and reference air kerma (Ka,r) were recorded for 100 consecutive cases satisfying the inclusion criteria. For each patient, a device specific dose correction factor, determined using a phantom, was used to standardize the KAP to that of the cylindrical diameter of the standard man and a collimation index was derived from the KAP and Ka,r. Median fluoroscopy time was 3 minutes (mean 4.5, range 1-23.8). Median KAP was 0.54 Gy/cm{sup 2} (mean 0.82, range 0.12-6.52). There was a significant decrease in KAP/second corrected for cylindrical diameter (p < 0.001) and the collimation index (p < 0.001) over time. This study shows that a dedicated dose reduction program can achieve very low total radiation dose rates for LVE. The significant decrease in collimation index and standardized KAP per second during this study suggest a learning curve for collimation. (orig.)

  2. SU-E-I-42: Normalized Embryo/fetus Doses for Fluoroscopically Guided Pacemaker Implantation Procedures Calculated Using a Monte Carlo Technique

    Energy Technology Data Exchange (ETDEWEB)

    Damilakis, J; Stratakis, J; Solomou, G [University of Crete, Heraklion (Greece)

    2014-06-01

    Purpose: It is well known that pacemaker implantation is sometimes needed in pregnant patients with symptomatic bradycardia. To our knowledge, there is no reported experience regarding radiation doses to the unborn child resulting from fluoroscopy during pacemaker implantation. The purpose of the current study was to develop a method for estimating embryo/fetus dose from fluoroscopically guided pacemaker implantation procedures performed on pregnant patients during all trimesters of gestation. Methods: The Monte Carlo N-Particle (MCNP) radiation transport code was employed in this study. Three mathematical anthropomorphic phantoms representing the average pregnant patient at the first, second and third trimesters of gestation were generated using Bodybuilder software (White Rock science, White Rock, NM). The normalized embryo/fetus dose from the posteroanterior (PA), the 30° left-anterior oblique (LAO) and the 30° right-anterior oblique (RAO) projections were calculated for a wide range of kVp (50–120 kVp) and total filtration values (2.5–9.0 mm Al). Results: The results consist of radiation doses normalized to a) entrance skin dose (ESD) and b) dose area product (DAP) so that the dose to the unborn child from any fluoroscopic technique and x-ray device used can be calculated. ESD normalized doses ranged from 0.008 (PA, first trimester) to 2.519 μGy/mGy (RAO, third trimester). DAP normalized doses ranged from 0.051 (PA, first trimester) to 12.852 μGy/Gycm2 (RAO, third trimester). Conclusion: Embryo/fetus doses from fluoroscopically guided pacemaker implantation procedures performed on pregnant patients during all stages of gestation can be estimated using the method developed in this study. This study was supported by the Greek Ministry of Education and Religious Affairs, General Secretariat for Research and Technology, Operational Program ‘Education and Lifelong Learning’, ARISTIA (Research project: CONCERT)

  3. SU-E-I-42: Normalized Embryo/fetus Doses for Fluoroscopically Guided Pacemaker Implantation Procedures Calculated Using a Monte Carlo Technique

    International Nuclear Information System (INIS)

    Damilakis, J; Stratakis, J; Solomou, G

    2014-01-01

    Purpose: It is well known that pacemaker implantation is sometimes needed in pregnant patients with symptomatic bradycardia. To our knowledge, there is no reported experience regarding radiation doses to the unborn child resulting from fluoroscopy during pacemaker implantation. The purpose of the current study was to develop a method for estimating embryo/fetus dose from fluoroscopically guided pacemaker implantation procedures performed on pregnant patients during all trimesters of gestation. Methods: The Monte Carlo N-Particle (MCNP) radiation transport code was employed in this study. Three mathematical anthropomorphic phantoms representing the average pregnant patient at the first, second and third trimesters of gestation were generated using Bodybuilder software (White Rock science, White Rock, NM). The normalized embryo/fetus dose from the posteroanterior (PA), the 30° left-anterior oblique (LAO) and the 30° right-anterior oblique (RAO) projections were calculated for a wide range of kVp (50–120 kVp) and total filtration values (2.5–9.0 mm Al). Results: The results consist of radiation doses normalized to a) entrance skin dose (ESD) and b) dose area product (DAP) so that the dose to the unborn child from any fluoroscopic technique and x-ray device used can be calculated. ESD normalized doses ranged from 0.008 (PA, first trimester) to 2.519 μGy/mGy (RAO, third trimester). DAP normalized doses ranged from 0.051 (PA, first trimester) to 12.852 μGy/Gycm2 (RAO, third trimester). Conclusion: Embryo/fetus doses from fluoroscopically guided pacemaker implantation procedures performed on pregnant patients during all stages of gestation can be estimated using the method developed in this study. This study was supported by the Greek Ministry of Education and Religious Affairs, General Secretariat for Research and Technology, Operational Program ‘Education and Lifelong Learning’, ARISTIA (Research project: CONCERT)

  4. Evaluation of the impact of a system for real-time visualisation of occupational radiation dose rate during fluoroscopically guided procedures

    International Nuclear Information System (INIS)

    Sandblom, V; Almén, A; Cederblad, A.; Båth, M; Lundh, C; Mai, T; Rystedt, H

    2013-01-01

    Optimisation of radiological protection for operators working with fluoroscopically guided procedures has to be performed during the procedure, under varying and difficult conditions. The aim of the present study was to evaluate the impact of a system for real-time visualisation of radiation dose rate on optimisation of occupational radiological protection in fluoroscopically guided procedures. Individual radiation dose measurements, using a system for real-time visualisation, were performed in a cardiology laboratory for three cardiologists and ten assisting nurses. Radiation doses collected when the radiation dose rates were not displayed to the staff were compared to radiation doses collected when the radiation dose rates were displayed. When the radiation dose rates were displayed to the staff, one cardiologist and the assisting nurses (as a group) significantly reduced their personal radiation doses. The median radiation dose (H p (10)) per procedure decreased from 68 to 28 μSv (p = 0.003) for this cardiologist and from 4.3 to 2.5 μSv (p = 0.001) for the assisting nurses. The results of the present study indicate that a system for real-time visualisation of radiation dose rate may have a positive impact on optimisation of occupational radiological protection. In particular, this may affect the behaviour of staff members practising inadequate personal radiological protection. (paper)

  5. Radiation brain dose to vascular surgeons during fluoroscopically guided interventions is not effectively reduced by wearing lead equivalent surgical caps.

    Science.gov (United States)

    Kirkwood, Melissa L; Arbique, Gary M; Guild, Jeffrey B; Zeng, Katie; Xi, Yin; Rectenwald, John; Anderson, Jon A; Timaran, Carlos

    2018-03-12

    Radiation to the interventionalist's brain during fluoroscopically guided interventions (FGIs) may increase the incidence of cerebral neoplasms. Lead equivalent surgical caps claim to reduce radiation brain doses by 50% to 95%. We sought to determine the efficacy of the RADPAD (Worldwide Innovations & Technologies, Lenexa, Kan) No Brainer surgical cap (0.06 mm lead equivalent at 90 kVp) in reducing radiation dose to the surgeon's and trainee's head during FGIs and to a phantom to determine relative brain dose reductions. Optically stimulated, luminescent nanoDot detectors (Landauer, Glenwood, Ill) inside and outside of the cap at the left temporal position were used to measure cap attenuation during FGIs. To check relative brain doses, nanoDot detectors were placed in 15 positions within an anthropomorphic head phantom (ATOM model 701; CIRS, Norfolk, Va). The phantom was positioned to represent a primary operator performing femoral access. Fluorography was performed on a plastic scatter phantom at 80 kVp for an exposure of 5 Gy reference air kerma with or without the hat. For each brain location, the percentage dose reduction with the hat was calculated. Means and standard errors were calculated using a pooled linear mixed model with repeated measurements. Anatomically similar locations were combined into five groups: upper brain, upper skull, midbrain, eyes, and left temporal position. This was a prospective, single-center study that included 29 endovascular aortic aneurysm procedures. The average procedure reference air kerma was 2.6 Gy. The hat attenuation at the temporal position for the attending physician and fellow was 60% ± 20% and 33% ± 36%, respectively. The equivalent phantom measurements demonstrated an attenuation of 71% ± 2.0% (P < .0001). In the interior phantom locations, attenuation was statistically significant for the skull (6% ± 1.4%) and upper brain (7.2% ± 1.0%; P < .0001) but not for the middle brain (1.4% ± 1.0%; P = .15

  6. Contemporary Australian dose area product levels in the fluoroscopic investigation of paediatric congenital heart disease

    International Nuclear Information System (INIS)

    Jones, T.; Brennan, P.C.; Mello-Thoms, C.; Ryan, E.

    2017-01-01

    This study examines radiation dose levels delivered to children from birth to 15 y of age in the investigation of congenital heart disease (CHD) at a major Sydney children's hospital. The aims are to compare values with those derived from similar studies, to provide a template for more consistent dose reporting, to establish local and national diagnostic reference levels and to contribute to the worldwide paediatric dosimetry database. A retrospective review of 1007 paediatric procedural records was undertaken. The cohort consisted of 795 patients over a period from January 2007 to December 2012 who have undergone cardiac catheterisation for the investigation of CHD. The age range included was from the day of birth to 15 y. Archived dose area product (DAP) and fluoroscopy time (FT) readings were retrieved and analysed. The mean, median, 25. and 75. percentile DAP levels were calculated for six specific age groupings. The 75. percentile DAP values for the specific age categories were as follows: 0-30 d-1.9 Gy cm 2 , 1-12 months-2.9 Gy cm 2 , 1-3 y-5.3 Gy cm 2 , 3-5 y-6.2 Gy cm 2 , 5-10 y-7.5 Gy cm 2 and 10-15 y-17.3 Gy cm 2 . These levels were found to be lower than the values reported in comparable overseas studies. Individual year-specific levels were determined, and it is proposed that these are more useful than the common grouping method. The age-specific 75. percentile DAP levels outlined in this study can be used as baseline local diagnostic reference levels. The needs for the standardisation of DAP reporting and for a greater range of age-specific diagnostic reference levels have been highlighted. For the first time, Australian dose values for paediatric cardiac catheterisation are presented. (authors)

  7. Data and methods to estimate fetal dose from fluoroscopically guided prophylactic hypogastric artery balloon occlusion

    Energy Technology Data Exchange (ETDEWEB)

    Solomou, G.; Stratakis, J. [Department of Medical Physics, Faculty of Medicine, University of Crete, P.O. Box 2208, Heraklion, Crete 71003 (Greece); Perisinakis, K.; Tsetis, D.; Damilakis, J., E-mail: john.damilakis@med.uoc.gr [Department of Medical Physics, Faculty of Medicine, University of Crete, P.O. Box 2208, Heraklion, Crete 71003, Greece and Department of Medical Physics, University Hospital of Heraklion, P.O. Box 1352, Heraklion, Crete 71110 (Greece)

    2016-06-15

    Purpose: To provide data for estimation of fetal radiation dose (D{sub F}) from prophylactic hypogastric artery balloon occlusion (HABO) procedures. Methods: The Monte-Carlo-N-particle (MCNP) transport code and mathematical phantoms representing a pregnant patient at the ninth month of gestation were employed. PA, RAO 20° and LAO 20° fluoroscopy projections of left and right internal iliac arteries were simulated. Projection-specific normalized fetal dose (NFD) data were produced for various beam qualities. The effects of projection angle, x-ray field location relative to the fetus, field size, maternal body size, and fetal size on NFD were investigated. Presented NFD values were compared to corresponding values derived using a physical anthropomorphic phantom simulating pregnancy at the third trimester and thermoluminescence dosimeters. Results: NFD did not considerably vary when projection angle was altered by ±5°, whereas it was found to markedly depend on tube voltage, filtration, x-ray field location and size, and maternal body size. Differences in NFD < 7.5% were observed for naturally expected variations in fetal size. A difference of less than 13.5% was observed between NFD values estimated by MCNP and direct measurements. Conclusions: Data and methods provided allow for reliable estimation of radiation burden to the fetus from HABO.

  8. Effect of a television digital noise reduction device on fluoroscopic image quality and dose rate

    International Nuclear Information System (INIS)

    Jaffe, C.C.; Orphanoudakis, S.C.; Ablow, R.C.

    1982-01-01

    In conventional fluoroscopy, the current, and therefore the dose rate, is usually determined by the level at which the radiologist visualizes a just tolerable amount of photon ''mottle'' on the video monitor. In this study, digital processing of the analogue video image reduced noise and generated a television image at half the usual exposure rate. The technique uses frame delay to compare an incoming frame with the preceding output frame. A first-order recursive filter implemented under a motion-detection scheme operates on the image of a point-by-point basis. This effective motion detection algorithm permits noise suppression without creating noticeable lag in moving structures. Eight radiologists evaluated images of vesicoureteral reflux in the pig for noise, contrast, resolution, and general image quality on a five-point preferential scale. They rated the digitally processed fluoroscopy images equivalent in diagnostic value to unprocessed images

  9. SU-G-IeP3-05: Effects of Image Receptor Technology and Dose Reduction Software On Radiation Dose Estimates for Fluoroscopically-Guided Interventional (FGI) Procedures

    Energy Technology Data Exchange (ETDEWEB)

    Merritt, Z; Dave, J; Eschelman, D; Gonsalves, C [Thomas Jefferson University, Philadelphia, PA (United States)

    2016-06-15

    Purpose: To investigate the effects of image receptor technology and dose reduction software on radiation dose estimates for most frequently performed fluoroscopically-guided interventional (FGI) procedures at a tertiary health care center. Methods: IRB approval was obtained for retrospective analysis of FGI procedures performed in the interventional radiology suites between January-2011 and December-2015. This included procedures performed using image-intensifier (II) based systems which were subsequently replaced, flat-panel-detector (FPD) based systems which were later upgraded with ClarityIQ dose reduction software (Philips Healthcare) and relatively new FPD system already equipped with ClarityIQ. Post procedure, technologists entered system-reported cumulative air kerma (CAK) and kerma-area product (KAP; only KAP for II based systems) in RIS; these values were analyzed. Data pre-processing included correcting typographical errors and cross-verifying CAK and KAP. The most frequent high and low dose FGI procedures were identified and corresponding CAK and KAP values were compared. Results: Out of 27,251 procedures within this time period, most frequent high and low dose procedures were chemo/immuno-embolization (n=1967) and abscess drainage (n=1821). Mean KAP for embolization and abscess drainage procedures were 260,657, 310,304 and 94,908 mGycm{sup 2}, and 14,497, 15,040 and 6307 mGycm{sup 2} using II-, FPD- and FPD with ClarityIQ- based systems, respectively. Statistically significant differences were observed in KAP values for embolization procedures with respect to different systems but for abscess drainage procedures significant differences were only noted between systems with FPD and FPD with ClarityIQ (p<0.05). Mean CAK reduced significantly from 823 to 308 mGy and from 43 to 21 mGy for embolization and abscess drainage procedures, respectively, in transitioning to FPD systems with ClarityIQ (p<0.05). Conclusion: While transitioning from II- to FPD- based

  10. Fluoroscopic Imaging Systems. Chapter 8

    Energy Technology Data Exchange (ETDEWEB)

    Jones, A. K. [University of Texas MD Anderson Cancer Center, Houston (United States)

    2014-09-15

    Fluoroscopy refers to the use of an X ray beam and a suitable image receptor for viewing images of processes or instruments in the body in real time. Fluoroscopic imaging trades the high signal to noise ratio (SNR) of radiography for high temporal resolution, as factors that maintain patient dose at an acceptable level must be used.

  11. Eye lens exposure to medical staff performing electrophysiology procedures: dose assessment and correlation to patient dose

    International Nuclear Information System (INIS)

    Ciraj-Bjelac, Olivera; Bozovic, Predrag; Arandjic, Danijela; Antic, Vojislav; Selakovic, Jovana; Pavlovic, Sinisa

    2016-01-01

    The purpose of this study was to assess the patient exposure and staff eye dose levels during implantation procedures for all types of pacemaker therapy devices performed under fluoroscopic guidance and to investigate potential correlation between patients and staff dose levels. The mean eye dose during pacemaker/defibrillator implementation was 12 μSv for the first operator, 8.7 μSv for the second operator/nurse and 0.50 μSv for radiographer. Corresponding values for cardiac re-synchronisation therapy procedures were 30, 26 and 2.0 μSv, respectively. Significant (p < 0.01) correlation between the eye dose and the kerma-area product was found for the first operator and radiographers, but not for other staff categories. The study revealed eye dose per procedure and eye dose normalised to patient dose indices for different staff categories and provided an input for radiation protection in electrophysiology procedures. (authors)

  12. Enjebi Island dose assessment

    International Nuclear Information System (INIS)

    Robison, W.L.; Conrado, C.L.; Phillips, W.A.

    1987-07-01

    We have updeated the radiological dose assessment for Enjebi Island at Enewetak Atoll using data derived from analysis of food crops grown on Enjebi. This is a much more precise assessment of potential doses to people resettling Enjebi Island than the 1980 assessment in which there were no data available from food crops on Enjebi. Details of the methods and data used to evaluate each exposure pathway are presented. The terrestrial food chain is the most significant potential exposure pathway and 137 Cs is the radionuclide responsible for most of the estimated dose over the next 50 y. The doses are calculated assuming a resettlement date of 1990. The average wholebody maximum annual estimated dose equivalent derived using our diet model is 166 mremy;the effective dose equivalent is 169 mremy. The estimated 30-, 50-, and 70-y integral whole-body dose equivalents are 3.5 rem, 5.1 rem, and 6.2 rem, respectively. Bone-marrow dose equivalents are only slightly higher than the whole-body estimates in each case. The bone-surface cells (endosteal cells) receive the highest dose, but they are a less sensitive cell population and are less sensitive to fatal cancer induction than whole body and bone marrow. The effective dose equivalents for 30, 50, and 70 y are 3.6 rem, 5.3 rem, and 6.6 rem, respectively. 79 refs., 17 figs., 24 tabs

  13. Radiation dose and intra-articular access: comparison of the lateral mortise and anterior midline approaches to fluoroscopically guided tibiotalar joint injections

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Ambrose J.; Torriani, Martin; Bredella, Miriam A.; Chang, Connie Y.; Simeone, Frank J.; Palmer, William E. [Massachusetts General Hospital, Department of Radiology, Division of Musculoskeletal Imaging and Intervention, Boston, MA (United States); Balza, Rene [Centro Medico de Occidente, Department of Radiology, Maracaibo (Venezuela, Bolivarian Republic of)

    2016-03-15

    To compare the lateral mortise and anterior midline approaches to fluoroscopically guided tibiotalar joint injections with respect to successful intra-articular needle placement, fluoroscopy time, radiation dose, and dose area product (DAP). This retrospective study was IRB-approved and HIPAA-compliant. 498 fluoroscopically guided tibiotalar joint injections were performed or supervised by one of nine staff radiologists from 11/1/2010-12/31/2013. The injection approach was determined by operator preference. Images were reviewed on a PACS workstation to determine the injection approach (lateral mortise versus anterior midline) and to confirm intra-articular needle placement. Fluoroscopy time (minutes), radiation dose (mGy), and DAP (μGy-m{sup 2}) were recorded and compared using the student's t-test (fluoroscopy time) or the Wilcoxon rank sum test (radiation dose and DAP). There were 246 lateral mortise injections and 252 anterior midline injections. Two lateral mortise injections were excluded from further analysis because no contrast was administered. Intra-articular location of the needle tip was documented in 242/244 lateral mortise injections and 252/252 anterior midline injections. Mean fluoroscopy time was shorter for the lateral mortise group than the anterior midline group (0.7 ± 0.5 min versus 1.2 ± 0.8 min, P < 0.0001). Mean radiation dose and DAP were less for the lateral mortise group than the anterior midline group (2.1 ± 3.7 mGy versus 2.5 ± 3.5 mGy, P = 0.04; 11.5 ± 15.3 μGy-m{sup 2} versus 13.5 ± 17.3 μGy-m{sup 2}, P = 0.006). Both injection approaches resulted in nearly 100 % rates of intra-articular needle placement, but the lateral mortise approach used approximately 40 % less fluoroscopy time and delivered 15 % lower radiation dose and DAP to the patient. (orig.)

  14. Intraarticular Sacroiliac Joint Injection Under Computed Tomography Fluoroscopic Guidance: A Technical Note to Reduce Procedural Time and Radiation Dose

    International Nuclear Information System (INIS)

    Paik, Nam Chull

    2016-01-01

    PurposeA technique for computed tomography fluoroscopy (CTF)-guided intraarticular (IA) sacroiliac joint (SIJ) injection was devised to limit procedural time and radiation dose.MethodsOur Institutional Review Board approved this retrospective analysis and waived the requirement for informed consent. Overall, 36 consecutive diagnostic or therapeutic IA SIJ injections (unilateral, 20; bilateral, 16) performed in 34 patients (female, 18; male, 16) with a mean age of 45.5 years (range 20–76 years) under CTF guidance were analyzed, assessing technical success (i.e., IA contrast spread), procedural time, and radiation dose.ResultsAll injections were successful from a technical perspective and were free of serious complications. Respective median procedural times and effective doses of SIJ injection were as follows: unilateral, 5.28 min (range 3.58–8.00 min) and 0.11 millisievert (mSv; range 0.07–0.24 mSv); and bilateral, 6.72 min (range 4.17–21.17 min) and 0.11 mSv (range 0.09–0.51 mSv).ConclusionsGiven the high rate of technical success achieved in limited time duration and with little radiation exposure, CTF-guided IA SIJ injection is a practical and low-risk procedure.

  15. Intraarticular Sacroiliac Joint Injection Under Computed Tomography Fluoroscopic Guidance: A Technical Note to Reduce Procedural Time and Radiation Dose

    Energy Technology Data Exchange (ETDEWEB)

    Paik, Nam Chull, E-mail: pncspine@gmail.com [Arumdaun Wooldul Spine Hospital, Department of Radiology (Korea, Republic of)

    2016-07-15

    PurposeA technique for computed tomography fluoroscopy (CTF)-guided intraarticular (IA) sacroiliac joint (SIJ) injection was devised to limit procedural time and radiation dose.MethodsOur Institutional Review Board approved this retrospective analysis and waived the requirement for informed consent. Overall, 36 consecutive diagnostic or therapeutic IA SIJ injections (unilateral, 20; bilateral, 16) performed in 34 patients (female, 18; male, 16) with a mean age of 45.5 years (range 20–76 years) under CTF guidance were analyzed, assessing technical success (i.e., IA contrast spread), procedural time, and radiation dose.ResultsAll injections were successful from a technical perspective and were free of serious complications. Respective median procedural times and effective doses of SIJ injection were as follows: unilateral, 5.28 min (range 3.58–8.00 min) and 0.11 millisievert (mSv; range 0.07–0.24 mSv); and bilateral, 6.72 min (range 4.17–21.17 min) and 0.11 mSv (range 0.09–0.51 mSv).ConclusionsGiven the high rate of technical success achieved in limited time duration and with little radiation exposure, CTF-guided IA SIJ injection is a practical and low-risk procedure.

  16. Functionality and operation of fluoroscopic automatic brightness control/automatic dose rate control logic in modern cardiovascular and interventional angiography systems: a report of Task Group 125 Radiography/Fluoroscopy Subcommittee, Imaging Physics Committee, Science Council.

    Science.gov (United States)

    Rauch, Phillip; Lin, Pei-Jan Paul; Balter, Stephen; Fukuda, Atsushi; Goode, Allen; Hartwell, Gary; LaFrance, Terry; Nickoloff, Edward; Shepard, Jeff; Strauss, Keith

    2012-05-01

    Task Group 125 (TG 125) was charged with investigating the functionality of fluoroscopic automatic dose rate and image quality control logic in modern angiographic systems, paying specific attention to the spectral shaping filters and variations in the selected radiologic imaging parameters. The task group was also charged with describing the operational aspects of the imaging equipment for the purpose of assisting the clinical medical physicist with clinical set-up and performance evaluation. Although there are clear distinctions between the fluoroscopic operation of an angiographic system and its acquisition modes (digital cine, digital angiography, digital subtraction angiography, etc.), the scope of this work was limited to the fluoroscopic operation of the systems studied. The use of spectral shaping filters in cardiovascular and interventional angiography equipment has been shown to reduce patient dose. If the imaging control algorithm were programmed to work in conjunction with the selected spectral filter, and if the generator parameters were optimized for the selected filter, then image quality could also be improved. Although assessment of image quality was not included as part of this report, it was recognized that for fluoroscopic imaging the parameters that influence radiation output, differential absorption, and patient dose are also the same parameters that influence image quality. Therefore, this report will utilize the terminology "automatic dose rate and image quality" (ADRIQ) when describing the control logic in modern interventional angiographic systems and, where relevant, will describe the influence of controlled parameters on the subsequent image quality. A total of 22 angiography units were investigated by the task group and of these one each was chosen as representative of the equipment manufactured by GE Healthcare, Philips Medical Systems, Shimadzu Medical USA, and Siemens Medical Systems. All equipment, for which measurement data were

  17. Functionality and operation of fluoroscopic automatic brightness control/automatic dose rate control logic in modern cardiovascular and interventional angiography systems: A Report of Task Group 125 Radiography/Fluoroscopy Subcommittee, Imaging Physics Committee, Science Council

    Energy Technology Data Exchange (ETDEWEB)

    Rauch, Phillip; Lin, Pei-Jan Paul; Balter, Stephen; Fukuda, Atsushi; Goode, Allen; Hartwell, Gary; LaFrance, Terry; Nickoloff, Edward; Shepard, Jeff; Strauss, Keith [Henry Ford Health System, Detroit, Michigan 48202 (United States); Beth Israel Deaconess Medical Center, Boston, Massachusetts 02115 (United States); Columbia University Medical Center, New York, New York 10032 (United States); Shiga Medical Center for Children, Moriyama City, Shiga-Ken, Japan 524-0022 (Japan); University of Virginia Health Science Center, Charlottesville, Virginia 22908 (United States); Baystate Health Systems, Inc., Springfield, Massachusetts 01199 (United States); Columbia University Medical Center, New York, New York 10032 (United States); University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030 (United States); Cincinnati Children' s Hospital Medical Center, Cincinnati, Ohio 45229 (United States)

    2012-05-15

    Task Group 125 (TG 125) was charged with investigating the functionality of fluoroscopic automatic dose rate and image quality control logic in modern angiographic systems, paying specific attention to the spectral shaping filters and variations in the selected radiologic imaging parameters. The task group was also charged with describing the operational aspects of the imaging equipment for the purpose of assisting the clinical medical physicist with clinical set-up and performance evaluation. Although there are clear distinctions between the fluoroscopic operation of an angiographic system and its acquisition modes (digital cine, digital angiography, digital subtraction angiography, etc.), the scope of this work was limited to the fluoroscopic operation of the systems studied. The use of spectral shaping filters in cardiovascular and interventional angiography equipment has been shown to reduce patient dose. If the imaging control algorithm were programmed to work in conjunction with the selected spectral filter, and if the generator parameters were optimized for the selected filter, then image quality could also be improved. Although assessment of image quality was not included as part of this report, it was recognized that for fluoroscopic imaging the parameters that influence radiation output, differential absorption, and patient dose are also the same parameters that influence image quality. Therefore, this report will utilize the terminology ''automatic dose rate and image quality'' (ADRIQ) when describing the control logic in modern interventional angiographic systems and, where relevant, will describe the influence of controlled parameters on the subsequent image quality. A total of 22 angiography units were investigated by the task group and of these one each was chosen as representative of the equipment manufactured by GE Healthcare, Philips Medical Systems, Shimadzu Medical USA, and Siemens Medical Systems. All equipment, for which

  18. Functionality and operation of fluoroscopic automatic brightness control/automatic dose rate control logic in modern cardiovascular and interventional angiography systems: A Report of Task Group 125 Radiography/Fluoroscopy Subcommittee, Imaging Physics Committee, Science Council

    International Nuclear Information System (INIS)

    Rauch, Phillip; Lin, Pei-Jan Paul; Balter, Stephen; Fukuda, Atsushi; Goode, Allen; Hartwell, Gary; LaFrance, Terry; Nickoloff, Edward; Shepard, Jeff; Strauss, Keith

    2012-01-01

    Task Group 125 (TG 125) was charged with investigating the functionality of fluoroscopic automatic dose rate and image quality control logic in modern angiographic systems, paying specific attention to the spectral shaping filters and variations in the selected radiologic imaging parameters. The task group was also charged with describing the operational aspects of the imaging equipment for the purpose of assisting the clinical medical physicist with clinical set-up and performance evaluation. Although there are clear distinctions between the fluoroscopic operation of an angiographic system and its acquisition modes (digital cine, digital angiography, digital subtraction angiography, etc.), the scope of this work was limited to the fluoroscopic operation of the systems studied. The use of spectral shaping filters in cardiovascular and interventional angiography equipment has been shown to reduce patient dose. If the imaging control algorithm were programmed to work in conjunction with the selected spectral filter, and if the generator parameters were optimized for the selected filter, then image quality could also be improved. Although assessment of image quality was not included as part of this report, it was recognized that for fluoroscopic imaging the parameters that influence radiation output, differential absorption, and patient dose are also the same parameters that influence image quality. Therefore, this report will utilize the terminology ''automatic dose rate and image quality'' (ADRIQ) when describing the control logic in modern interventional angiographic systems and, where relevant, will describe the influence of controlled parameters on the subsequent image quality. A total of 22 angiography units were investigated by the task group and of these one each was chosen as representative of the equipment manufactured by GE Healthcare, Philips Medical Systems, Shimadzu Medical USA, and Siemens Medical Systems. All equipment, for which measurement data were

  19. Assessment of internal doses

    CERN Document Server

    Rahola, T; Falk, R; Isaksson, M; Skuterud, L

    2002-01-01

    There is a definite need for training in dose calculation. Our first course was successful and was followed by a second, both courses were fully booked. An example of new tools for software products for bioassay analysis and internal dose assessment is the Integrated Modules for Bioassay Analysis (IMBA) were demonstrated at the second course. This suite of quality assured code modules have been adopted in the UK as the standard for regulatory assessment purposes. The intercomparison measurements are an important part of the Quality Assurance work. In what is known as the sup O utside workers ' directive it is stated that the internal dose measurements shall be included in the European Unions supervision system for radiation protection. The emergency preparedness regarding internal contamination was much improved by the training with and calibration of handheld instruments from participants' laboratories. More improvement will be gained with the handbook giving practical instructions on what to do in case of e...

  20. Reference air kerma and kerma-area product as estimators of peak skin dose for fluoroscopically guided interventions

    International Nuclear Information System (INIS)

    Kwon, Deukwoo; Little, Mark P.; Miller, Donald L.

    2011-01-01

    Purpose: To determine more accurate regression formulas for estimating peak skin dose (PSD) from reference air kerma (RAK) or kerma-area product (KAP). Methods: After grouping of the data from 21 procedures into 13 clinically similar groups, assessments were made of optimal clustering using the Bayesian information criterion to obtain the optimal linear regressions of (log-transformed) PSD vs RAK, PSD vs KAP, and PSD vs RAK and KAP. Results: Three clusters of clinical groups were optimal in regression of PSD vs RAK, seven clusters of clinical groups were optimal in regression of PSD vs KAP, and six clusters of clinical groups were optimal in regression of PSD vs RAK and KAP. Prediction of PSD using both RAK and KAP is significantly better than prediction of PSD with either RAK or KAP alone. The regression of PSD vs RAK provided better predictions of PSD than the regression of PSD vs KAP. The partial-pooling (clustered) method yields smaller mean squared errors compared with the complete-pooling method.Conclusion: PSD distributions for interventional radiology procedures are log-normal. Estimates of PSD derived from RAK and KAP jointly are most accurate, followed closely by estimates derived from RAK alone. Estimates of PSD derived from KAP alone are the least accurate. Using a stochastic search approach, it is possible to cluster together certain dissimilar types of procedures to minimize the total error sum of squares.

  1. Fluoroscopically guided transforaminal epidural steroid injections at a quaternary-care teaching institution: effect of trainee involvement and patient body mass index on fluoroscopy time and patient dose

    International Nuclear Information System (INIS)

    Tiegs-Heiden, C.A.; Murthy, N.S.; Geske, J.R.; Diehn, F.E.; Schueler, B.A.; Wald, J.T.; Kaufmann, T.J.; Lehman, V.T.; Carr, C.M.; Amrami, K.K.; Morris, J.M.; Thielen, K.R.; Maus, T.P.

    2016-01-01

    Aim: To investigate whether there are differences in fluoroscopy time and patient dose for fluoroscopically guided lumbar transforaminal epidural steroid injections (TFESIs) performed by staff radiologists versus with trainees and to evaluate the effect of patient body mass index (BMI) on fluoroscopy time and patient dose, including their interactions with other variables. Materials and methods: Single-level lumbar TFESIs (n=1844) between 1 January 2011 and 31 December 2013 were reviewed. Fluoroscopy time, reference point air kerma (K_a_,_r), and kerma area product (KAP) were recorded. BMI and trainee involvement were examined as predictors of fluoroscopy time, K_a_,_r, and KAP in models adjusted for age and gender in multivariable linear models. Stratified models of BMI groups by trainee presence were performed. Results: Increased age was the only significant predictor of increased fluoroscopy time (p<0.0001). K_a_,_r and KAP were significantly higher in patients with a higher BMI (p<0.0001 and p=0.0009). When stratified by BMI, longer fluoroscopy time predicted increased K_a_,_r and KAP in all groups (p<0.0001). Trainee involvement was not a statistically significant predictor of fluoroscopy time or K_a_,_r in any BMI category. KAP was lower with trainees in the overweight group (p=0.0009) and higher in male patients for all BMI categories (p<0.02). Conclusion: Trainee involvement did not result in increased fluoroscopy time or patient dose. BMI did not affect fluoroscopy time; however, overweight and obese patients received significantly higher K_a_,_r and KAP. Male patients received a higher KAP in all BMI categories. Limiting fluoroscopy time and good collimation practices should be reinforced in these patients. - Highlights: • Trainee involvement did not contribute to increased fluoroscopy time or dose. • BMI did not affect fluoroscopy time. • Overweight and obese patients received significantly higher Ka,r and KAP.

  2. Dose. Detriment. Limit assessment

    International Nuclear Information System (INIS)

    Breckow, J.

    2015-01-01

    One goal of radiation protection is the limitation of stochastic effects due to radiation exposure. The probability of occurrence of a radiation induced stochastic effect, however, is only one of several other parameters which determine the radiation detriment. Though the ICRP-concept of detriment is a quantitative definition, the kind of detriment weighting includes somewhat subjective elements. In this sense, the detriment-concept of ICRP represents already at the stage of effective dose a kind of assessment. Thus, by comparing radiation protection standards and concepts interconvertible or with those of environment or occupational protection one should be aware of the possibly different principles of detriment assessment.

  3. Eye lens dose correlations with personal dose equivalent and patient exposure in paediatric interventional cardiology performed with a fluoroscopic biplane system.

    Science.gov (United States)

    Alejo, L; Koren, C; Corredoira, E; Sánchez, F; Bayón, J; Serrada, A; Guibelalde, E

    2017-04-01

    To analyse the correlations between the eye lens dose estimates performed with dosimeters placed next to the eyes of paediatric interventional cardiologists working with a biplane system, the personal dose equivalent measured on the thorax and the patient dose. The eye lens dose was estimated in terms of H p (0.07) on a monthly basis, placing optically stimulated luminescence dosimeters (OSLDs) on goggles. The H p (0.07) personal dose equivalent was measured over aprons with whole-body OSLDs. Data on patient dose as recorded by the kerma-area product (P KA ) were collected using an automatic dose management system. The 2 paediatric cardiologists working in the facility were involved in the study, and 222 interventions in a 1-year period were evaluated. The ceiling-suspended screen was often disregarded during interventions. The annual eye lens doses estimated on goggles were 4.13±0.93 and 4.98±1.28mSv. Over the aprons, the doses obtained were 10.83±0.99 and 11.97±1.44mSv. The correlation between the goggles and the apron dose was R 2 =0.89, with a ratio of 0.38. The correlation with the patient dose was R 2 =0.40, with a ratio of 1.79μSvGy -1 cm -2 . The dose per procedure obtained over the aprons was 102±16μSv, and on goggles 40±9μSv. The eye lens dose normalized to P KA was 2.21±0.58μSvGy -1 cm -2 . Measurements of personal dose equivalent over the paediatric cardiologist's apron are useful to estimate eye lens dose levels if no radiation protection devices are typically used. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  4. The ALARA (as low as reasonably achievable) concept in pediatric interventional and fluoroscopic imaging: striving to keep radiation doses as low as possible during fluoroscopy of pediatric patients - a white paper executive summary

    International Nuclear Information System (INIS)

    Strauss, Keith J.; Kaste, Sue C.

    2006-01-01

    ALARA represents a practice mandate adhering to the principle of keeping radiation doses to patients and personnel As Low As Reasonably Achievable. This concept is strongly endorsed by the Society for Pediatric Radiology, particularly in the use of procedures and modalities involving higher radiation doses such as CT and fluoroscopic examinations of pediatric patients. There is no doubt that medical imaging, which has undergone tremendous technological advances in recent decades, is integral to patient care. However, these technological advances generally precede the knowledge of end-users concerning the optimal use and correct operation of the resulting imaging equipment, and such knowledge is essential to minimizing potential risks to the patients. Current imaging methods must be optimized for radiation dose reduction in pediatric patients who might be as much as ten times more radiosensitive than adults. Unlike straightforward radiographic examinations, radiation dose to the patient during fluoroscopy is dependent on the operator's training, experience with the fluoroscope, and efficiency in completing a diagnostic study. The range of pediatric radiation doses from fluoroscopy is wide because this examination is performed not only by pediatric radiologists but also by general radiologists who occasionally care for children, interventional cardiologists, gastroenterologists, urologists and others. Thus, a venue where multidisciplinary interaction by this variety of operators can occur serves to improve pediatric patient care

  5. A review of two methods used in the USA to assess HE during fluoroscopic-based radiology

    International Nuclear Information System (INIS)

    Craig Yoder, R.; Salasky, Mark R.

    2016-01-01

    Dosemeter results for ∼81 500 people performing fluoroscopic and interventional radiology procedures were examined to identify differences between groups monitored either by using two dosemeters, one placed at the collar above the apron and a second placed under the apron on the torso (EDE1) or by using one single dosemeter placed at the collar above the apron (EDE2). The median annual HE was 0.17 mSv for those monitored using the EDE1 protocol and 0.26 mSv for the group using the EDE2 protocol. The EDE2 method was used most frequently with the EDE1 method preferred for those more highly exposed. Approximately, 22 % of dosemeter results for EDE1 were inconsistent with expected norms based on over and under apron dosemeter relationships. (authors)

  6. Consultative exercise on dose assessments.

    Science.gov (United States)

    Bridges, B A; Parker, T; Simmonds, J R; Sumner, D

    2001-06-01

    A summary is given of a meeting held at Sussex University, UK, in October 2000, which allowed the exchange of ideas on methods of assessment of dose to the public arising from potential authorised radioactive discharges from nuclear sites in the UK. Representatives of groups with an interest in dose assessments were invited, and hence the meeting was called the Consultative Exercise on Dose Assessments (CEDA). Although initiated and funded by the Food Standards Agency, its organisation, and the writing of the report, were overseen by an independent Chairman and Steering Group. The report contains recommendations for improvement in co-ordination between different agencies involved in assessments, on method development and on the presentation of data on assessments. These have been prepared by the Steering Group, and will be taken forward by the Food Standards Agency and other agencies in the UK. The recommendations are included in this memorandum.

  7. Dose assessment in radiological accidents

    International Nuclear Information System (INIS)

    Donkor, S.

    2013-04-01

    The applications of ionizing radiation bring many benefits to humankind, ranging from power generation to uses in medicine, industry and agriculture. Facilities that use radiation source require special care in the design and operation of equipment to prevent radiation injury to workers or to the public. Despite considerable development of radiation safety, radiation accidents do happen. The purpose of this study is therefore to discuss how to assess doses to people who will be exposed to a range of internal and external radiation sources in the event of radiological accidents. This will go a long way to complement their medical assessment thereby helping to plan their treatment. Three radiological accidents were reviewed to learn about the causes of those accidents and the recommendations that were put in place to prevent recurrence of such accidents. Various types of dose assessment methods were discussed.(au)

  8. Dose assessments for SFR 1

    International Nuclear Information System (INIS)

    Bergstroem, Ulla; Avila, Rodolfo; Ekstroem, Per-Anders; Cruz, Idalmis de la

    2008-05-01

    Following a review by the Swedish regulatory authorities of the safety analysis of the SFR 1 disposal facility for low and intermediate level waste, SKB has prepared an updated safety analysis, SAR-08. This report presents estimations of annual doses to the most exposed groups from potential radionuclide releases from the SFR 1 repository for a number of calculation cases, selected using a systematic approach for identifying relevant scenarios for the safety analysis. The dose estimates can be used for demonstrating that the long term safety of the repository is in compliance with the regulatory requirements. In particular, the mean values of the annual doses can be used to estimate the expected risks to the most exposed individuals, which can then be compared with the regulatory risk criteria for human health. The conversion from doses to risks is performed in the main report. For one scenario however, where the effects of an earthquake taking place close to the repository are analysed, risk calculations are presented in this report. In addition, prediction of concentrations of radionuclides in environmental media, such as water and soil, are compared with concentration limits suggested by the Erica-project as a base for estimating potential effects on the environment. The assessment of the impact on non-human biota showed that the potential impact is negligible. Committed collective dose for an integration period of 10,000 years for releases occurring during the first thousand years after closure are also calculated. The collective dose commitment was estimated to be 8 manSv. The dose calculations were carried out for a period of 100,000 years, which was sufficient to observe peak doses in all scenarios considered. Releases to the landscape and to a well were considered. The peaks of the mean annual doses from releases to the landscape are associated with C-14 releases to a future lake around year 5,000 AD. In the case of releases to a well, the peak annual doses

  9. Dose assessments for SFR 1

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, Ulla (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)); Avila, Rodolfo; Ekstroem, Per-Anders; Cruz, Idalmis de la (Facilia AB, Bromma (Sweden))

    2008-06-15

    Following a review by the Swedish regulatory authorities of the safety analysis of the SFR 1 disposal facility for low and intermediate level waste, SKB has prepared an updated safety analysis, SAR-08. This report presents estimations of annual doses to the most exposed groups from potential radionuclide releases from the SFR 1 repository for a number of calculation cases, selected using a systematic approach for identifying relevant scenarios for the safety analysis. The dose estimates can be used for demonstrating that the long term safety of the repository is in compliance with the regulatory requirements. In particular, the mean values of the annual doses can be used to estimate the expected risks to the most exposed individuals, which can then be compared with the regulatory risk criteria for human health. The conversion from doses to risks is performed in the main report. For one scenario however, where the effects of an earthquake taking place close to the repository are analysed, risk calculations are presented in this report. In addition, prediction of concentrations of radionuclides in environmental media, such as water and soil, are compared with concentration limits suggested by the Erica-project as a base for estimating potential effects on the environment. The assessment of the impact on non-human biota showed that the potential impact is negligible. Committed collective dose for an integration period of 10,000 years for releases occurring during the first thousand years after closure are also calculated. The collective dose commitment was estimated to be 8 manSv. The dose calculations were carried out for a period of 100,000 years, which was sufficient to observe peak doses in all scenarios considered. Releases to the landscape and to a well were considered. The peaks of the mean annual doses from releases to the landscape are associated with C-14 releases to a future lake around year 5,000 AD. In the case of releases to a well, the peak annual doses

  10. Occupational dose assessment and national dose registry system in Iran

    International Nuclear Information System (INIS)

    Jafari-Zadeh, M.; Nazeri, F.; Hosseini-Pooya, S. M.; Taheri, M.; Gheshlaghi, F.; Kardan, M. R.; Babakhani, A.; Rastkhah, N.; Yousefi-Nejad, F.; Darabi, M.; Oruji, T.; Gholamali-Zadeh, Z.; Karimi-Diba, J.; Kazemi-Movahed, A. A.; Dashti-Pour, M. R.; Enferadi, A.; Jahanbakhshian, M. H.; Sadegh-Khani, M. R.

    2011-01-01

    This report presents status of external and internal dose assessment of workers and introducing the structure of National Dose Registry System of Iran (NDRSI). As well as types of individual dosemeters in use, techniques for internal dose assessment are presented. Results obtained from the International Atomic Energy Agency intercomparison programme on measurement of personal dose equivalent H p (10) and consistency of the measured doses with the delivered doses are shown. Also, implementation of dosimetry standards, establishment of quality management system, authorisation and approval procedure of dosimetry service providers are discussed. (authors)

  11. General-purpose radiographic and fluoroscopic table

    International Nuclear Information System (INIS)

    Ishizaki, Noritaka

    1982-01-01

    A new series of diagnostic tables, Model DT-KEL, was developed for general-purpose radiographic and fluoroscopic systems. Through several investigations, the table was so constructed that the basic techniques be general radiography and GI examination, and other techniques be optionally added. The diagnostic tables involve the full series of the type for various purposes and are systematized with the surrounding equipment. A retractable mechanism of grids was adopted first for general use. The fine grids with a density of 57 lines per cm, which was adopted in KEL-2, reduced the X-ray doses by 16 percent. (author)

  12. Comparing radiation exposure during percutaneous vertebroplasty using one- vs. two-fluoroscopic technique

    Directory of Open Access Journals (Sweden)

    Li Yen-Yao

    2013-01-01

    Full Text Available Abstract Background Percutaneous vertebroplasty (PV requires relatively lengthy fluoroscopic guidance, which might lead to substantial radiation exposure to patients or operators. The two-fluoroscopic technique (two-plane radiographs obtained using two fluoroscopes during PV can provide simultaneous two-planar projections with reducing operative time. However, the two-fluoroscopic technique may expose the operator or patient to increased radiation dose. The aim of this study was to quantify the amount of radiation exposure to the patient or operator that occurs during PV using one- vs. two-fluoroscopic technique. Methods Two radiation dosimeters were placed on the right flank of each patient and on the upper sternum of each operator during 26 single-level PV procedures by one senior surgeon. The use of two-fluoroscopic technique (13 patients and one-fluoroscopic technique (13 patients were allocated in a consecutive and alternative manner. The operative time and mean radiation dose to each patient and operator were monitored and compared between groups. Results Mean radiation dose to the patient was 1.97 ± 1.20 mSv (95% CI, 0.71 to 3.23 for the one-fluoroscopic technique group vs. 0.95 ± 0.34 mSv (95% CI, 0.85 to 1.23 for the two-fluoroscopic technique group (P =0.031. Mean radiation dose to the operator was 0.27 ± 0.12 mSv (95% CI, 0.17–0.56 for the one-fluoroscopic technique group vs. 0.25 ± 0.14 mSv (95% CI, 0.06–0.44 for the two-fluoroscopic technique group (P = 0.653. The operative time was significantly different between groups: 47.15 ± 13.48 min (range, 20–75 for the one-fluoroscopic technique group vs. 36.62 ± 8.42 min (range, 21–50 for the two-fluoroscopic technique group (P =0.019. Conclusion Compared to the one-fluoroscopic technique, the two-fluoroscopic technique used during PV provides not only shorter operative times but also reduces the radiation exposure to the patient. There was no

  13. Irrigation in dose assessments models

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, Ulla; Barkefors, Catarina [Studsvik RadWaste AB, Nykoeping (Sweden)

    2004-05-01

    SKB has carried out several safety analyses for repositories for radioactive waste, one of which was SR 97, a multi-site study concerned with a future deep bedrock repository for high-level waste. In case of future releases due to unforeseen failure of the protective multiple barrier system, radionuclides may be transported with groundwater and may reach the biosphere. Assessments of doses have to be carried out with a long-term perspective. Specific models are therefore employed to estimate consequences to man. It has been determined that the main pathway for nuclides from groundwater or surface water to soil is via irrigation. Irrigation may cause contamination of crops directly by e.g. interception or rain-splash, and indirectly via root-uptake from contaminated soil. The exposed people are in many safety assessments assumed to be self-sufficient, i.e. their food is produced locally where the concentration of radionuclides may be the highest. Irrigation therefore plays an important role when estimating consequences. The present study is therefore concerned with a more extensive analysis of the role of irrigation for possible future doses to people living in the area surrounding a repository. Current irrigation practices in Sweden are summarised, showing that vegetables and potatoes are the most common crops for irrigation. In general, however, irrigation is not so common in Sweden. The irrigation model used in the latest assessments is described. A sensitivity analysis is performed showing that, as expected, interception of irrigation water and retention on vegetation surfaces are important parameters. The parameters used to describe this are discussed. A summary is also given how irrigation is proposed to be handled in the international BIOMASS (BIOsphere Modelling and ASSessment) project and in models like TAME and BIOTRAC. Similarities and differences are pointed out. Some numerical results are presented showing that surface contamination in general gives the

  14. Irrigation in dose assessments models

    International Nuclear Information System (INIS)

    Bergstroem, Ulla; Barkefors, Catarina

    2004-05-01

    SKB has carried out several safety analyses for repositories for radioactive waste, one of which was SR 97, a multi-site study concerned with a future deep bedrock repository for high-level waste. In case of future releases due to unforeseen failure of the protective multiple barrier system, radionuclides may be transported with groundwater and may reach the biosphere. Assessments of doses have to be carried out with a long-term perspective. Specific models are therefore employed to estimate consequences to man. It has been determined that the main pathway for nuclides from groundwater or surface water to soil is via irrigation. Irrigation may cause contamination of crops directly by e.g. interception or rain-splash, and indirectly via root-uptake from contaminated soil. The exposed people are in many safety assessments assumed to be self-sufficient, i.e. their food is produced locally where the concentration of radionuclides may be the highest. Irrigation therefore plays an important role when estimating consequences. The present study is therefore concerned with a more extensive analysis of the role of irrigation for possible future doses to people living in the area surrounding a repository. Current irrigation practices in Sweden are summarised, showing that vegetables and potatoes are the most common crops for irrigation. In general, however, irrigation is not so common in Sweden. The irrigation model used in the latest assessments is described. A sensitivity analysis is performed showing that, as expected, interception of irrigation water and retention on vegetation surfaces are important parameters. The parameters used to describe this are discussed. A summary is also given how irrigation is proposed to be handled in the international BIOMASS (BIOsphere Modelling and ASSessment) project and in models like TAME and BIOTRAC. Similarities and differences are pointed out. Some numerical results are presented showing that surface contamination in general gives the

  15. Exposure dose assessment using bioassay

    International Nuclear Information System (INIS)

    Suga, Shinichi

    1994-01-01

    Bioassay involves following steps: sampling, pre-treatment, chemical separation and counting of radioactivity. As bioassay samples, urines are usually used, although faecal analysis may be required in some occasions for example to assess intake of non-transferable radioactive materials. Nasal smear is a useful indicator of an inhalation case. Exhalation air is used to estimate the intake of tritiated water. Sample pre-treatment includes evaporation for concentration, wet ashing, dry ashing and co-precipitation. After adding small amount of nitric acid, the sample can be concentrated by 1/10 of initial volume, which may be used to identify γ-emitters. As the pre-treatment of urine, wet ashing is used for example for analysis of Pu, and co-precipitation is used for example for analysis of Sr. Dry ashing by electric furnace is usually adopted for faecal samples. Methods of chemical separation depend on the radionuclide(s) to be analysed. The detection limit depends also on radionuclide, and for example typical detection limits are 0.4Bq / l (volume of urine sample) for 89 Sr or 90 Sr, and 0.01 Bq / l with urine and 0.01 Bq per sample with faeces for 238 Pu, 239 Pu or 241 Am. Simpler methods can be used for some radionuclides: For example, radioactivity concentration of tritium can be determined by liquid scintillation counting of urine or condensed water from exhaled air, and natural uranium in urine can be quantified by using fluorometric method. In some circumstances, gross-α or gross-β analyses are useful for quick estimation. To estimate intakes by inhalation or by ingestion from bioassay results and to assess the committed dose equivalent, commonly available bases are the relevant publications by the ICRP and domestic guides and manuals that conform to the radiation protection regulations. (author)

  16. Dose assessment at Bikini Atoll

    International Nuclear Information System (INIS)

    Robison, W.L.; Phillips, W.A.; Colsher, C.S.

    1977-01-01

    Bikini Atoll is one of two sites in the northern Marshall Islands that was used by the United States as testing grounds for the nuclear weapons program from 1946 to 1958. In 1969 a general cleanup began at Bikini Atoll. Subsistence crops, coconut and Pandanus fruit, were planted on Bikini and Eneu Islands, and housing was constructed on Bikini Island. A second phase of housing was planned for the interior of Bikini Island. Preliminary data indicated that external gamma doses in the interior of the island might be higher than in other parts of the island. Therefore, to select a second site for housing on the island with minimum external exposure, a survey of Bikini Atoll was conducted in June 1975. External gamma measurements were made on Bikini and Eneu Islands, and soil and vegetations samples collected to evaluate the potential doses via terrestrial food chains and inhalation. Estimates of potential dose via the marine food chain were based upon data collected on previous trips to the atoll. The terrestrial pathway contributes the greater percentage, external gamma exposure contributes the next highest, and inhalation and marine pathways contribute minor fractions of the total whole body and bone marrow doses. The radionuclides contributing the major fraction of the dose are 90 Sr and 137 Cs. All living patterns involving Bikini Island exceed federal guidelines for 30-yr population doses. The Eneu Island living pattern leads to doses that are slightly less than federal guidelines. All patterns evaluated for Bikini Atoll lead to higher doses than those on the southern islands at Enewetak Atoll

  17. 4D cone beam CT-based dose assessment for SBRT lung cancer treatment

    International Nuclear Information System (INIS)

    Cai, Weixing; Dhou, Salam; Cifter, Fulya; Myronakis, Marios; Hurwitz, Martina H; Williams, Christopher L; Berbeco, Ross I; Seco, Joao; Lewis, John H

    2016-01-01

    The purpose of this research is to develop a 4DCBCT-based dose assessment method for calculating actual delivered dose for patients with significant respiratory motion or anatomical changes during the course of SBRT. To address the limitation of 4DCT-based dose assessment, we propose to calculate the delivered dose using time-varying (‘fluoroscopic’) 3D patient images generated from a 4DCBCT-based motion model. The method includes four steps: (1) before each treatment, 4DCBCT data is acquired with the patient in treatment position, based on which a patient-specific motion model is created using a principal components analysis algorithm. (2) During treatment, 2D time-varying kV projection images are continuously acquired, from which time-varying ‘fluoroscopic’ 3D images of the patient are reconstructed using the motion model. (3) Lateral truncation artifacts are corrected using planning 4DCT images. (4) The 3D dose distribution is computed for each timepoint in the set of 3D fluoroscopic images, from which the total effective 3D delivered dose is calculated by accumulating deformed dose distributions. This approach is validated using six modified XCAT phantoms with lung tumors and different respiratory motions derived from patient data. The estimated doses are compared to that calculated using ground-truth XCAT phantoms. For each XCAT phantom, the calculated delivered tumor dose values generally follow the same trend as that of the ground truth and at most timepoints the difference is less than 5%. For the overall delivered dose, the normalized error of calculated 3D dose distribution is generally less than 3% and the tumor D95 error is less than 1.5%. XCAT phantom studies indicate the potential of the proposed method to accurately estimate 3D tumor dose distributions for SBRT lung treatment based on 4DCBCT imaging and motion modeling. Further research is necessary to investigate its performance for clinical patient data. (paper)

  18. 3D delivered dose assessment using a 4DCT-based motion model

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Weixing; Hurwitz, Martina H.; Williams, Christopher L.; Dhou, Salam; Berbeco, Ross I.; Mishra, Pankaj, E-mail: wcai@lroc.harvard.edu, E-mail: jhlewis@lroc.harvard.edu; Lewis, John H., E-mail: wcai@lroc.harvard.edu, E-mail: jhlewis@lroc.harvard.edu [Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115 (United States); Seco, Joao [Francis H. Burr Proton Therapy Center, Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02115 (United States)

    2015-06-15

    reconstructed from kV and MV projections compared to the ground truth, which is clinically comparable to 4DCT (0.093%). For the second XCAT phantom that has an irregular breathing pattern, the errors are 0.81% and 1.75% for kV and MV reconstructions, both of which are better than that of 4DCT (4.01%). In the case of real patient, although it is impossible to obtain the actual delivered dose, the dose estimation is clinically reasonable and demonstrates differences between 4DCT and MV reconstruction-based dose estimates. Conclusions: With the availability of kV or MV projection images, the proposed approach is able to assess delivered doses for all respiratory phases during treatment. Compared to the planning dose based on 4DCT, the dose estimation using reconstructed 3D fluoroscopic images was as good as 4DCT for regular respiratory pattern and was a better dose estimation for the irregular respiratory pattern.

  19. 3D delivered dose assessment using a 4DCT-based motion model

    International Nuclear Information System (INIS)

    Cai, Weixing; Hurwitz, Martina H.; Williams, Christopher L.; Dhou, Salam; Berbeco, Ross I.; Mishra, Pankaj; Lewis, John H.; Seco, Joao

    2015-01-01

    reconstructed from kV and MV projections compared to the ground truth, which is clinically comparable to 4DCT (0.093%). For the second XCAT phantom that has an irregular breathing pattern, the errors are 0.81% and 1.75% for kV and MV reconstructions, both of which are better than that of 4DCT (4.01%). In the case of real patient, although it is impossible to obtain the actual delivered dose, the dose estimation is clinically reasonable and demonstrates differences between 4DCT and MV reconstruction-based dose estimates. Conclusions: With the availability of kV or MV projection images, the proposed approach is able to assess delivered doses for all respiratory phases during treatment. Compared to the planning dose based on 4DCT, the dose estimation using reconstructed 3D fluoroscopic images was as good as 4DCT for regular respiratory pattern and was a better dose estimation for the irregular respiratory pattern

  20. AGING FACILITY WORKER DOSE ASSESSMENT

    International Nuclear Information System (INIS)

    R.L. Thacker

    2005-01-01

    The purpose of this calculation is to estimate radiation doses received by personnel working in the Aging Facility performing operations to transfer aging casks to the aging pads for thermal and logistical management, stage empty aging casks, and retrieve aging casks from the aging pads for further processing in other site facilities. Doses received by workers due to aging cask surveillance and maintenance operations are also included. The specific scope of work contained in this calculation covers both collective doses and individual worker group doses on an annual basis, and includes the contributions due to external and internal radiation from normal operation. There are no Category 1 event sequences associated with the Aging Facility (BSC 2004 [DIRS 167268], Section 7.2.1). The results of this calculation will be used to support the design of the Aging Facility and to provide occupational dose estimates for the License Application. The calculations contained in this document were developed by Environmental and Nuclear Engineering of the Design and Engineering Organization and are intended solely for the use of the Design and Engineering Organization in its work regarding facility operation. Yucca Mountain Project personnel from the Environmental and Nuclear Engineering should be consulted before use of the calculations for purposes other than those stated herein or use by individuals other than authorized personnel in Environmental and Nuclear Engineering

  1. Howard Hughes Medical Institute dose assessment survey

    International Nuclear Information System (INIS)

    O'Brien, S.L.; McDougall, M.M.; Barkley, W.E.

    1996-01-01

    Biomedical science researchers often express frustration that health physics practices vary widely between individual institutions. A survey examining both internal and external dose assessment practices was devised and mailed to fifty institutions supporting biomedical science research. The results indicate that health physics dose assessment practices and policies are highly variable. Factors which may contribute to the degree of variation are discussed. 2 tabs

  2. Dose assessment models. Annex A

    International Nuclear Information System (INIS)

    1982-01-01

    The models presented in this chapter have been separated into 2 general categories: environmental transport models which describe the movement of radioactive materials through all sectors of the environment after their release, and dosimetric models to calculate the absorbed dose following an intake of radioactive materials or exposure to external irradiation. Various sections of this chapter also deal with atmospheric transport models, terrestrial models, and aquatic models.

  3. Research and assessment of national population dose

    International Nuclear Information System (INIS)

    Pan Ziqiang

    1984-01-01

    This article describes the necessity and probability of making researches on assessment of national population dose, and discusses some problems which might be noticeable in the research work. (author)

  4. Calculational Tool for Skin Contamination Dose Assessment

    CERN Document Server

    Hill, R L

    2002-01-01

    Spreadsheet calculational tool was developed to automate the calculations preformed for dose assessment of skin contamination. This document reports on the design and testing of the spreadsheet calculational tool.

  5. Thermoluminescent dosimetry and assessment of personal dose

    International Nuclear Information System (INIS)

    Boas, J.F.; Martin, L.J.; Young, J.G.

    1982-01-01

    Thermoluminescence is discussed in terms of the energy band structure of a crystalline solid and the trapping of charge carriers by point defects. Some general properties of thermoluminescent materials used for dosimetry are outlined, with thermoluminescence of CaSO 4 :Dy being described in detail. The energy response function and the modification of the energy response of a dosimeter by shielding are discussed. The final section covers the connection between exposure, as recorded by a TLD badge, and the absorbed dose to various organs from gamma radiation in a uranium mine; the conversion from absorbed dose to dose equivalent; and uncertainties in assessment of dose equivalent

  6. Assessment of peak skin dose in interventional cardiology: A comparison between Gafchromic film and dosimetric software em.dose.

    Science.gov (United States)

    Greffier, J; Van Ngoc Ty, C; Bonniaud, G; Moliner, G; Ledermann, B; Schmutz, L; Cornillet, L; Cayla, G; Beregi, J P; Pereira, F

    2017-06-01

    To compare the use of a dose mapping software to Gafchromic film measurement for a simplified peak skin dose (PSD) estimation in interventional cardiology procedure. The study was conducted on a total of 40 cardiac procedures (20 complex coronary angioplasty of chronic total occlusion (CTO) and 20 coronary angiography and coronary angioplasty (CA-PTCA)) conducted between January 2014 to December 2015. PSD measurement (PSD Film ) was obtained by placing XR-RV3 Gafchromic under the patient's back for each procedure. PSD (PSD em.dose ) was computed with the software em.dose©. The calculation was performed on the dose metrics collected from the private dose report of each procedure. Two calculation methods (method A: fluoroscopic kerma equally spread on cine acquisition and B: fluoroscopic kerma is added to one air Kerma cine acquisition that contributes to the PSD) were used to calculate the fluoroscopic dose contribution as fluoroscopic data were not recorded in our interventional room. Statistical analyses were carried out to compare PSD Film and PSD em.dose . The PSD Film median (1st quartile; 3rd quartile) was 0.251(0.190;0.336)Gy for CA-PTCA and 1.453(0.767;2.011)Gy for CTO. For method-A, the PSD em.dose was 0.248(0.182;0.369)Gy for CA-PTCA and 1.601(0.892;2.178)Gy for CTO, and 0.267(0.223;0.446)Gy and 1.75 (0.912;2.584)Gy for method-B, respectively. For the two methods, the correlation between PSD Film and PSD em.dose was strong. For all cardiology procedures investigated, the mean deviation between PSD Film and PSD em.dose was 3.4±21.1% for method-A and 17.3%±23.9% for method-B. The dose mapping software is convenient to calculate peak skin dose in interventional cardiology. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  7. An updated dose assessment for Rongelap Island

    Energy Technology Data Exchange (ETDEWEB)

    Robison, W.L.; Conrado, C.L.; Bogen, K.T.

    1994-07-01

    We have updated the radiological dose assessment for Rongelap Island at Rongelap Atoll using data generated from field trips to the atoll during 1986 through 1993. The data base used for this dose assessment is ten fold greater than that available for the 1982 assessment. Details of each data base are presented along with details about the methods used to calculate the dose from each exposure pathway. The doses are calculated for a resettlement date of January 1, 1995. The maximum annual effective dose is 0.26 mSv y{sup {minus}1} (26 mrem y{sup {minus}1}). The estimated 30-, 50-, and 70-y integral effective doses are 0.0059 Sv (0.59 rem), 0.0082 Sv (0.82 rem), and 0.0097 Sv (0.97 rem), respectively. More than 95% of these estimated doses are due to 137-Cesium ({sup 137}Cs). About 1.5% of the estimated dose is contributed by 90-Strontium ({sup 90}Sr), and about the same amount each by 239+240-Plutonium ({sup 239+240}PU), and 241-Americium ({sup 241}Am).

  8. Radiation dose in vertebroplasty

    International Nuclear Information System (INIS)

    Mehdizade, A.; Lovblad, K.O.; Wilhelm, K.E.; Somon, T.; Wetzel, S.G.; Kelekis, A.D.; Yilmaz, H.; Abdo, G.; Martin, J.B.; Viera, J.M.; Ruefenacht, D.A.

    2004-01-01

    We wished to measure the absorbed radiation dose during fluoroscopically controlled vertebroplasty and to assess the possibility of deterministic radiation effects to the operator. The dose was measured in 11 consecutive procedures using thermoluminescent ring dosimeters on the hand of the operator and electronic dosimeters inside and outside of the operator's lead apron. We found doses of 0.022-3.256 mGy outside and 0.01-0.47 mGy inside the lead apron. Doses on the hand were higher, 0.5-8.5 mGy. This preliminary study indicates greater exposure to the operator's hands than expected from traditional apron measurements. (orig.)

  9. Dose assessment for brachytherapy with Henschke applicator

    International Nuclear Information System (INIS)

    Yu, Pei-Chieh; Chao, Tsi-Chian; Tung, Chuan-Jong; Wu, Ching-Jung; Lee, Chung-Chi

    2011-01-01

    Dose perturbation caused by the Henschke applicator is a major concern for the brachytherapy planning system (BPS) in recent years. To investigate dose impact owing to neglect of the metal shielding effect, Monte Carlo (MC) simulation, BPS calculation, and film measurement have been performed for dose assessment in a water phantom. Additionally, a cylindrical air cavity representing the rectum was added into the MC simulation to study its effect on dose distribution. Monte Carlo N-Particle Transport Code (MCNP) was used in this study to simulate the dose distribution using a mesh tally. This Monte Carlo simulation has been validated using the TG-43 data in a previous report. For the measurement, the Henschke applicator was placed in a specially-designed phantom, and Gafchromic films were inserted in the center plane for 2D dose assessment. Isodose distributions with and without the Henschke applicator by the MC simulation show significant deviation from those by the BPS. For MC simulation, the isodose curves shrank more significantly when the metal applicator was applied. For the impact of the added air cavity, the results indicate that it is hard to distinguish between with and without the cavity. Thus, the rectum cavity has little impact on the dose distribution around the Henschke applicator.

  10. Local dose assessment for a contaminated wound

    International Nuclear Information System (INIS)

    Piechowski, J.; Chaptinel, Y.

    2004-01-01

    Contaminated wounds present a great variability concerning the type of lesion. Assessment of the local dose is one amongst other factors for a decision as to the surgical operation. A simple model has been used to calculate the doses in a representative volume, that of a phalanx for instance. The dose rates are given for current radionuclides. The method of calculation is enough simple in order to allow the practitioners to use it in situations involving other radionuclides. Committed dose depends on the biological half-life which can be estimated from the local measurements. Some examples of calculation of committed dose are given considering half-lives characteristic of the compound. Transposition of the dose to the local risk is easy for the non-stochastic risk. Conversely, this is not the case for the risk of chronic inflammation or cancer. The latter question could only be solved by a feedback based on the analysis of real till now observed cases, nevertheless taking into account the fact that the available data are generally not so easy to make use for establishing an unquestionable dose - effect relation. A critical issue remains open as to the use of these doses for their comparison to the regulatory limits and for the subsequent decisions in case of exceeding the limits. The actual impact of an irradiation, especially by alpha particles, is not linked to the calculated dose in a simple and direct way. This question needs further consideration and perhaps a practical guide concerning this topic would be useful. The anatomical (surgical side effects), psychological and professional consequences should have a large weight relatively to the doses, obviously except for the cases, involving actually large contamination. (authors)

  11. Internal dose assessment in radiation accidents

    International Nuclear Information System (INIS)

    Toohey, R.E.

    2003-01-01

    Although numerous models have been developed for occupational and medical internal dosimetry, they may not be applicable to an accident situation. Published dose coefficients relate effective dose to intake, but if acute deterministic effects are possible, effective dose is not a useful parameter. Consequently, dose rates to the organs of interest need to be computed from first principles. Standard bioassay methods may be used to assess body contents, but, again, the standard models for bioassay interpretation may not be applicable because of the circumstances of the accident and the prompt initiation of decorporation therapy. Examples of modifications to the standard methodologies include adjustment of biological half-times under therapy, such as in the Goiania accident, and the same effect, complicated by continued input from contaminated wounds, in the Hanford 241 Am accident. (author)

  12. The embryogenesis of dose assessment at Hanford

    International Nuclear Information System (INIS)

    Foster, R.F.

    1990-01-01

    Several significant events occurred between 1955 and 1960 that resulted in major changes in environmental monitoring at Hanford and in the initiation of comprehensive dose assessments. These included: (1) specification of dose limits for nonoccupational exposure (including internal emitters); (2) a national and international awakening to the need for managing the disposal of radioactive wastes; (3) identification of the most important radionuclides and their sources of exposure; (4) data that quantified the transfer coefficients of nuclides along environmental pathways; and (5) development of greatly improved radiation detection instrumentation. In response to a growing need, the Hanford Laboratories formed the Environmental Studies and Evaluation component. This group revamped the monitoring and sampling programs so that analytical results contributed directly to dose estimation. Special studies were conducted to ascertain local dietary and recreational habits that affected dose calculations and to calibrate the models. These studies involved extensive contact with the public and governmental agencies, which elicited a positive reaction

  13. Inhalation dose assessment for Maralinga and Emu

    International Nuclear Information System (INIS)

    Johnston, P.N.; Lokan, K.H.; Williams, G.A.

    1990-01-01

    Dose assessments for the inhalation of artificial radionuclides are presented for all types of contaminated areas at Maralinga and Emu. These enable Committed Effective Dose Equivalent (CEDE), to be estimated by scaling at any area of interest where activity concentrations are known. In the case of Aborigines, these dose are estimated assuming respirable dust loadings of 1 mg/m 3 for adults and 1.5 mg/m 3 for children and infants. Details of the calculations are presented in the appendix. The model of the respiratory system used in this assessment is that described in Interantional Commission on Radiological Protection (ICRP) Publication 30 (ICRP, 1979a). With the exception of Kuli, which is contaminated with uranium, at all other sites it is only the inhalation of plutonium and americium that contributes significantly to the dose, and of these 239 Pu is the largest contributor. Therefore, considering the long half lives of the radionuclides concerned, it appears that the inhalation problems highlighted by this dose assessment will not diminish significantly within any reasonable period of time and hence management strategies must be developed to deal with such problems. 32 refs., 5 tabs., 1 fig

  14. Dose assessment for Greifswald and Cadarache

    International Nuclear Information System (INIS)

    Raskob, W.

    1996-07-01

    Probabilistic dose assessments for accidental atmospheric releases of tritium and activation products as well as releases under normal operation conditions were performed for the sites of Greifswald, Germany, and Cadarache, France. Additionally, aquatic releases were considered for both sites. No country specific rules were applied and the input parameters were adapted as far as possible to those used within former ITER studies to have a better comparison to site independent dose assessments performed in the frame of ITER. The main goal was to complete the generic data base with site specific values. The agreement between the results from the ITER study on atmospheric releases and the two sites are rather good for tritium, whereas the ITER reference dose values for the activation product releases are often lower, than the maximum doses for Greifswald and Cadarache. However, the percentile values fit better to the deterministic approach of ITER. Within all scenarios, the consequences of aquatic releases are in nearly all cases smaller than those from comparable releases to the atmosphere (HTO and steel). This rule is only broken once in case of accidental releases of activated steel from Cadarache. However, the uncertainties associated with the aquatic assessments are rather high and a better data base is needed to obtain more realistic and thus more reliable dose values. (orig.) [de

  15. The MESORAD dose assessment model: Computer code

    International Nuclear Information System (INIS)

    Ramsdell, J.V.; Athey, G.F.; Bander, T.J.; Scherpelz, R.I.

    1988-10-01

    MESORAD is a dose equivalent model for emergency response applications that is designed to be run on minicomputers. It has been developed by the Pacific Northwest Laboratory for use as part of the Intermediate Dose Assessment System in the US Nuclear Regulatory Commission Operations Center in Washington, DC, and the Emergency Management System in the US Department of Energy Unified Dose Assessment Center in Richland, Washington. This volume describes the MESORAD computer code and contains a listing of the code. The technical basis for MESORAD is described in the first volume of this report (Scherpelz et al. 1986). A third volume of the documentation planned. That volume will contain utility programs and input and output files that can be used to check the implementation of MESORAD. 18 figs., 4 tabs

  16. Assessment of external dose indoors in Lithuania

    International Nuclear Information System (INIS)

    Pilkyte, L.; Butkus, D.; Morkunas, G.

    2006-01-01

    The aim of this paper was an assessment of external exposure indoors and its dependence on construction materials and indoor radon concentrations in Lithuanian living houses. Relationship of absorbed dose rate in air indoors and activity indexes of the most commonly used construction materials (wood, concrete and bricks) have been studied using results received in measurements done in >4700 rooms in 1995-2005. Possible connections of dose rate indoors with indoor radon concentrations are also discussed. Findings of this study helped to make an assessment of the mean value of effective dose of Lithuanian population due to external exposure indoors which is equal to 0.58 mSv y -1 . The received data might also be used in improvement of quality of personal dosimetric measurements done in premises constructed of different construction materials. (authors)

  17. Human data and internal dose assessment

    International Nuclear Information System (INIS)

    Kawamura, H.; Tanaka, G.; Shiraishi, K.; Yamamoto, M.

    1992-01-01

    Recent data on physical and anatomical and physiological or metabolic data regarding Japanese Reference Man is briefly reviewed. This includes reference values for masses of all organs and tissues proposed for a Japanese Reference male adult. Part of the data is used to assess alpha doses to bone tissues from naturally occurring 226 Ra in bone of Japanese adult. (author)

  18. Determination of environmental radioactivity for dose assessment

    International Nuclear Information System (INIS)

    Nakoaka, A.; Fukushima, M.; Takagi, S.

    1980-01-01

    A method was devised to determine detection limits for radioactivity in environmental samples. The method is based on the 5 mrem/yr whole-body dose objective established by the Japan Atomic Enerty Commission and is valid for assessing the internal dose from radionuclides in the environment around a nuclear facility. Eleven samples and 15 radionuclides were considered. Internal dose was assumed to be one-half of the total dose (5 mrem/yr) and was assessed using the critical pathway method. Needed detection limits (NDLs) were established to confirm the dose of 5 mrem/yr when there was more than one radionuclide per sample. The NDLs for γ-emitters were 10 -5 pCi/l. for air; 10 -3 pCi/l. for seawater; 10 -1 pCi/l. for drinking water; 10 0 pCi/kg for vegetables and fish; 10 0 pCi/l. for milk; and 10 1 pCi/kg for molluscs, crustaceans, seaweeds, soil and submarine sediments. The NDLs for β-emitters were 1-1/100 of those for γ-emitters. (author)

  19. Real time source term and dose assessment

    International Nuclear Information System (INIS)

    Breznik, B.; Kovac, A.; Mlakar, P.

    2001-01-01

    The Dose Projection Programme is a tool for decision making in case of nuclear emergency. The essential input data for quick emergency evaluation in the case of hypothetical pressurised water reactor accident are following: source term, core damage assessment, fission product radioactivity, release source term and critical exposure pathways for an early phase of the release. A reduced number of radio-nuclides and simplified calculations can be used in dose calculation algorithm. Simple expert system personal computer programme has been developed for the Krsko Nuclear Power Plant for dose projection within the radius of few kilometers from the pressurised water reactor in early phase of an accident. The input data are instantaneous data of core activity, core damage indicators, release fractions, reduction factor of the release pathways, spray operation, release timing, and dispersion coefficient. Main dose projection steps are: accurate in-core radioactivity determination using reactor power input; core damage and in-containment source term assessment based on quick indications of instrumentation or on activity analysis data; user defines release pathway for typical PWR accident scenarius; dose calculation is performed only for exposure pathway critical for decision about evacuation or sheltering in early phase of an accident.(author)

  20. Dose assessment in the Marshall Islands

    International Nuclear Information System (INIS)

    Robison, William L.

    1978-01-01

    Bikini Atoll and Enewetak Atoll in the Marshall Islands were the sites of major U.S. weapons testing from 1948 through 1958. Both the Bikini and Knewetak people have expressed a desire to return to their native Atolls. In 1968 clean-up and resettlement of Bikini was begun. In 1972-73 the initial survey of Enewetak Atoll was conducted and clean-up began in 1977. Surveys have been conducted at both Atolls to establish the concentrations of radionuclides in the biota and to determine the external exposure rates. Subsequent to the surveys dose assessments have been made to determine the potential dose to returning (100) populations at both Atolls. This talk will include discussions of the relative importance of the critical exposure pathways (i.e., external exposure, inhalation, marine, terrestrial and drinking water), the predominant radionuclides contributing to the predicted doses for each pathway, the doses predicted for alternate living patterns, comparison to Federal Guidelines, the comparison between Atolls, some of the social problems created by adherence to Federal Guidelines and the follow-up research identified and initiated to help refine the dose assessments and better predict the long term use of the Atolls (86). (author)

  1. Bio-indicators for radiation dose assessment

    International Nuclear Information System (INIS)

    Trivedi, A.

    1990-12-01

    In nuclear facilities, such as Chalk River Laboratories, dose to the atomic radiation workers (ARWs) is assessed routinely by using physical dosimeters and bioassay procedures in accordance with regulatory recommendations. However, these procedures may be insufficient in some circumstances, e.g., in cases where the reading of the physical dosimeters is questioned, in cases of radiation accidents where the person(s) in question was not wearing a dosimeter, or in the event of a radiation emergency when an exposure above the dose limits is possible. The desirability of being able to assess radiation dose on the basis of radio-biological effects has prompted the Dosimetric Research Branch to investigate the suitability of biological devices and techniques that could be used for this purpose. Current biological dosimetry concepts suggest that there does not appear to be any bio-indicator that could reliably measure the very low doses that are routinely measured by the physical devices presently in use. Nonetheless, bio-indicators may be useful in providing valuable supplementary information in cases of unusual radiation exposures, such as when the estimated body doses are doubtful because of lack of proper physical measurements, or in cases where available results need to be confirmed for medical treatment plannings. This report evaluates the present state of biological dosimetry and, in particular, assesses the efficiency and limits of individual indicators. This has led to the recommendation of a few promising research areas that may result in the development of appropriate biological dosimeters for operational and emergency needs at Chalk River

  2. Uncertainty on faecal analysis on dose assessment

    Energy Technology Data Exchange (ETDEWEB)

    Juliao, Ligia M.Q.C.; Melo, Dunstana R.; Sousa, Wanderson de O.; Santos, Maristela S.; Fernandes, Paulo Cesar P. [Instituto de Radioprotecao e Dosimetria, Comissao Nacional de Energia Nuclear, Av. Salvador Allende s/n. Via 9, Recreio, CEP 22780-160, Rio de Janeiro, RJ (Brazil)

    2007-07-01

    Monitoring programmes for internal dose assessment may need to have a combination of bioassay techniques, e.g. urine and faecal analysis, especially in workplaces where compounds of different solubilities are handled and also in cases of accidental intakes. Faecal analysis may be an important data for assessment of committed effective dose due to exposure to insoluble compounds, since the activity excreted by urine may not be detectable, unless a very sensitive measurement system is available. This paper discusses the variability of the daily faecal excretion based on data from just one daily collection; collection during three consecutive days: samples analysed individually and samples analysed as a pool. The results suggest that just 1 d collection is not appropriate for dose assessment, since the 24 h uranium excretion may vary by a factor of 40. On the basis of this analysis, the recommendation should be faecal collection during three consecutive days, and samples analysed as a pool, it is more economic and faster. (authors)

  3. Dose. Detriment. Limit assessment; Dosis. Schadensmass. Grenzwertsetzung

    Energy Technology Data Exchange (ETDEWEB)

    Breckow, J. [Technische Hochschule Mittelhessen, Giessen (Germany). Inst. fuer Medizinische Physik und Strahlenschutz (IMPS)

    2015-07-01

    One goal of radiation protection is the limitation of stochastic effects due to radiation exposure. The probability of occurrence of a radiation induced stochastic effect, however, is only one of several other parameters which determine the radiation detriment. Though the ICRP-concept of detriment is a quantitative definition, the kind of detriment weighting includes somewhat subjective elements. In this sense, the detriment-concept of ICRP represents already at the stage of effective dose a kind of assessment. Thus, by comparing radiation protection standards and concepts interconvertible or with those of environment or occupational protection one should be aware of the possibly different principles of detriment assessment.

  4. Dose assessment under incidental and accidental conditions

    International Nuclear Information System (INIS)

    Huebschmann, W.G.

    1988-01-01

    Dose assessment for the licesing process of a nuclear power plant covers the routine release of radioactive substances into the atmosphere as well as releases due to incidents. Source terms for these incidents are evaluated by the detailed incident analysis of the plant. The types of incidents to be covered are determined in the FRG by the ''Stoerfall-Leitlinien'' of the Ministry of the Interior. The calculation of dose equivalents in the environment of the plant differs from the calculation of doses due to routine releases, as incidents are single events occuring at undeterminate time, and the results must be conservative. Some details are being described. During the operation of the plant it is essential to measure not only the radioactivity release rates but also the necessary meteorological parameters for the instantaneous determination of the atmospheric dispersion in case of incidental or accidental releases of radioactivity. This instantaneous assessment assists in taking measurements of ground contamination and in deciding about countermeasures for the protection of plant personnell and population. (author) [pt

  5. Thermoluminescence dosemeter for personal dose equivalent assessment

    International Nuclear Information System (INIS)

    Silva, T.A. da; Rosa, L.A.R. da; Campos, L.L.

    1995-01-01

    The possibility was investigated of utilising a Brazilian thermoluminescence individual dosemeter, usually calibrated in terms of photon dose equivalent, for the assessment of the personal dose equivalent, H p (d), at depths of 0.07 and 10 mm. The dosemeter uses four CaSO 4 :Dy thermoluminescent detectors, between different filters, as the sensitive materials. It was calibrated in gamma and X radiation fields in the energy range from 17 to 1250 keV. Linear combinations of the responses of three detectors, in this energy range, allow the evaluation of H p (0.07) and H p (10), for radiation incidence angles varying from 0 to 60 degrees, with an accuracy better than 35%. The method is not applicable to mixed photon-beta fields. (author)

  6. Combination TLD/TED dose assessment

    International Nuclear Information System (INIS)

    Parkhurst, M.A.

    1992-11-01

    During the early 1980s, an appraisal of dosimetry programs at US Department of Energy (DOE) facilities identified a significant weakness in dose assessment in fast neutron environments. Basing neutron dose equivalent on thermoluminescence dosimeters (TLDS) was not entirely satisfactory for environments that had not been well characterized. In most operational situations, the dosimeters overrespond to neutrons, and this overresponse could be further exaggerated with changes in the neutron quality factor (Q). Because TLDs are energy dependent with an excellent response to thermal and low-energy neutrons but a weak response to fast neutrons, calibrating the dosimetry system to account for mixed and moderated neutron energy fields is a difficult and seldom satisfactory exercise. To increase the detection of fast neutrons and help improve the accuracy of dose equivalent determinations, a combination dosimeter was developed using TLDs to detect thermal and low-energy neutrons and a track-etch detector (TED) to detect fast neutrons. By combining the albedo energy response function of the TLDs with the track detector elements, the dosimeter can nearly match the fluence-to-dose equivalent conversion curve. The polymer CR-39 has neutron detection characteristics superior to other materials tested. The CR-39 track detector is beta and gamma insensitive and does not require backscatter (albedo) from the body to detect the exposure. As part of DOE's Personnel Neutron and Upgrade Program, we have been developing a R-39 track detector over the past decade to address detection and measurement of fast neutrons. Using CR-39 TEDs in combination with TLDs will now allow us to detect the wide spectrum of occupational neutron energies and assign dose equivalents much more confidently

  7. Assessment of Organ Radiation Dose Associated with Uterine Artery Embolization

    International Nuclear Information System (INIS)

    Glomset, O.; Hellesnes, J.; Heimland, N.; Hafsahl, G.; Smith, H.J.

    2006-01-01

    Purpose: To evaluate the radiation dose to the skin, uterus, and ovaries during uterine artery embolization. Material and Methods: Guided uterine artery embolization for leiomyomata and two types of X-ray equipment with different dose levels were utilized during fluoroscopy in 20 women (ages ranging from 32 to 52 years, body weights from 55 to 68 kg). The first 13 women were treated using a non-pulsed system A, with 3.3 mm Al filtering and, for simplicity, a fixed peak voltage 80 kV. During treatment of the other 7 women, a pulsed system B with 5.4 mm Al filtering and an identical fixed voltage was used. The dose area product (DAP) was recorded. The vaginal dose of the first 13 patients and the peak skin dose of all patients were measured with thermoluminescent dosimeters (TLDs). TLDs were placed in the posterior vaginal fornix and on the skin at the beam entrance site. The uterine and ovarian doses were estimated based on the measured skin doses, normalized depth dose, and organ depth values. The effective dose (D eff ) was estimated based on the observed DAP values. The measured vaginal doses and the corresponding estimated uterine doses were compared statistically, as were the DAP values from systems A and B. Results: For system A, the mean fluoroscopic time was 20.9 min (range 12.7-31.1), and for system B 35.9 min (range 16.4-55.4). The mean numbers of angiographic exposures for systems A and B were 82 (range 30-164) and 37 (range 20-72), respectively. The mean peak skin dose for system A was 601.5 mGy (range 279-1030) and for system B 453 mGy (range 257-875). The mean DAP for system A was 88.6 Gy cm 2 (range 41.4-161.0) and for system B 52.5 Gy cm 2 (range 20.1-107.9). Statistical analysis showed a significant difference between the DAP values, the DAP for system B being the lower one. The mean estimated effective doses from systems A and B were 32 mSv (range 15.1-58.4) and 22 mSv (range 9-46), respectively. The mean estimated maximum uterine and ovarian doses

  8. Assessment of dose during an SGTR

    International Nuclear Information System (INIS)

    Adams, J.P.

    1993-01-01

    The Nuclear Regulatory Commission requires utilities to determine the response of a pressurized water reactor to a steam generator tube rupture (SGTR) as part of the safety analysis for the plant. The SGTR analysis includes assumptions regarding the iodine concentration in the reactor coolant system (RCS) due to iodine spikes, primary flashing and bypass fractions, and iodine partitioning in the secondary coolant system (SCS). Experimental and analytical investigations have recently been completed wherein these assumptions were tested to determine whether and to what degree they were conservative (that is, whether they result in a calculated iodine source term/dose that is at least as large or larger than that expected during an actual event). The current study has the objective to assess the overall effects of the results of these investigations on the calculated iodine dose to the environment during an SGTR. To assist in this study, a computer program, DOSE, was written. This program uses a simple, non-mechanistic model to calculate the iodine source term to the environment during an SGTR as a function of water mass inventories and flow rates and iodine concentrations in the RCS and SCS. The principal conclusion of this study is that the iodine concentration in the RCS is the dominant parameter, due to the dominance of primary flashing on the iodine source term

  9. Dose assessment considering evolution of the biosphere

    International Nuclear Information System (INIS)

    Karlsson, Sara; Bergstroem, Ulla

    2002-01-01

    Swedish Nuclear Fuel and Waste Management AB (SKB) is presently updating the safety assessment for SFR (Final repository for radioactive operational waste) in Sweden. The bio-spheric part of the analysis is performed by Studsvik Eco and Safety AB. According to the regulations the safety of the repository has to be accounted for different possible courses of the development of the biosphere. A number of studies have been carried out during the past years to investigate and document the biosphere in the area surrounding the repository. Modelling of shore-level displacement by land uplift, coastal water exchange and sedimentation have provided data for prediction of the evolution of the area. The prediction is done without considering a future change in climatic conditions. The results from this study show that accumulation of radionuclides in sediments is an important process to simulate when performing dose assessments covering biosphere evolution. The dose calculated for the first years of the period with agricultural use of the contaminated sediments may be severely underestimated in a scenario with large accumulation in coastal and lake stages. (LN)

  10. Reducing radiation exposure in an electrophysiology lab with introduction of newer fluoroscopic technology

    Directory of Open Access Journals (Sweden)

    Munish Sharma

    2017-09-01

    Full Text Available The use of fluoroscopic devices exposes patients and operators to harmful effects of ionizing radiation in an electrophysiology (EP lab. We sought to know if the newer fluoroscopic technology (Allura Clarity installed in a hybrid EP helps to reduce prescribed radiation dose. We performed radiation dose analysis of 90 patients who underwent various procedures in the EP lab at a community teaching hospital after the introduction of newer fluoroscopic technology in June of 2016.Watchman device insertion, radiofrequency ablation procedures, permanent pacemaker (PPM/implantable cardioverter defibrillator (ICD placement and battery changes were included in the study to compare radiation exposure during different procedures performed commonly in an EP lab. In all cases of watchman device placement, radiofrequency ablation procedures, PPM/ICD placement and battery changes, there was a statistically significant difference (<0.05 in radiation dose exposure. Significant reduction in radiation exposure during various procedures performed in an EP lab was achieved with aid of newer fluoroscopic technology and better image detection technology.

  11. Wound trauma alters ionizing radiation dose assessment

    Directory of Open Access Journals (Sweden)

    Kiang Juliann G

    2012-06-01

    Full Text Available Abstract Background Wounding following whole-body γ-irradiation (radiation combined injury, RCI increases mortality. Wounding-induced increases in radiation mortality are triggered by sustained activation of inducible nitric oxide synthase pathways, persistent alteration of cytokine homeostasis, and increased susceptibility to bacterial infection. Among these factors, cytokines along with other biomarkers have been adopted for biodosimetric evaluation and assessment of radiation dose and injury. Therefore, wounding could complicate biodosimetric assessments. Results In this report, such confounding effects were addressed. Mice were given 60Co γ-photon radiation followed by skin wounding. Wound trauma exacerbated radiation-induced mortality, body-weight loss, and wound healing. Analyses of DNA damage in bone-marrow cells and peripheral blood mononuclear cells (PBMCs, changes in hematology and cytokine profiles, and fundamental clinical signs were evaluated. Early biomarkers (1 d after RCI vs. irradiation alone included significant decreases in survivin expression in bone marrow cells, enhanced increases in γ-H2AX formation in Lin+ bone marrow cells, enhanced increases in IL-1β, IL-6, IL-8, and G-CSF concentrations in blood, and concomitant decreases in γ-H2AX formation in PBMCs and decreases in numbers of splenocytes, lymphocytes, and neutrophils. Intermediate biomarkers (7 – 10 d after RCI included continuously decreased γ-H2AX formation in PBMC and enhanced increases in IL-1β, IL-6, IL-8, and G-CSF concentrations in blood. The clinical signs evaluated after RCI were increased water consumption, decreased body weight, and decreased wound healing rate and survival rate. Late clinical signs (30 d after RCI included poor survival and wound healing. Conclusion Results suggest that confounding factors such as wounding alters ionizing radiation dose assessment and agents inhibiting these responses may prove therapeutic for radiation combined

  12. New Jersey's Thomas Edison and the fluoroscope.

    Science.gov (United States)

    Tselos, G D

    1995-11-01

    Thomas Edison played a major role in the development of early x-ray technology in 1896, notably increasing tube power and reliability and making the fluoroscope a practical instrument. Eventually, Edison would move x-ray technology from the laboratory to the marketplace.

  13. Preliminary dose assessment of the Chernobyl accident

    International Nuclear Information System (INIS)

    Hull, A.P.

    1987-01-01

    From the major accident at Unit 4 of the Chernobyl nuclear power station, a plume of airborne radioactive fission products was initially carried northwesterly toward Poland, thence toward Scandinavia and into Central Europe. Reports of the levels of radioactivity in a variety of media and of external radiation levels were collected in the Department of Energy's Emergency Operations Center and compiled into a data bank. Portions of these and other data which were obtained directly from published and official reports were utilized to make a preliminary assessment of the extent and magnitude of the external dose to individuals downwind from Chernobyl. Radioactive 131 I was the predominant fission product. The time of arrival of the plume and the maximum concentrations of 131 I in air, vegetation and milk and the maximum reported depositions and external radiation levels have been tabulated country by country. A large amount of the total activity in the release was apparently carried to a significant elevation. The data suggest that in areas where rainfall occurred, deposition levels were from ten to one-hundred times those observed in nearby ''dry'' locations. Sufficient spectral data were obtained to establish average release fractions and to establish a reference spectra of the other nuclides in the release. Preliminary calculations indicated that the collective dose equivalent to the population in Scandinavia and Central Europe during the first year after the Chernobyl accident would be about 8 x 10 6 person-rem. From the Soviet report, it appears that a first year population dose of about 2 x 10 7 person-rem (2 x 10 5 Sv) will be received by the population who were downwind of Chernobyl within the U.S.S.R. during the accident and its subsequent releases over the following week. 32 refs., 14 figs., 20 tabs

  14. Population dose assessment: characteristics of PC CREAM

    International Nuclear Information System (INIS)

    Alonso, Maria T.; Curti, Adriana R.

    2000-01-01

    This paper presents the main features of the PC CREAM, a program for performing radiological impact assessments due to radioactive discharges into the environment during the operation of radioactive and nuclear facilities. PC CREAM is a suite of six programs that can be used to estimate individual and collective radiation doses. The methodology of PC CREAM is based on updated environmental and dosimetric models, including ICRP 60 recommendations. The models include several exposure pathways and the input files are easy to access. The ergonomics of the program improves the user interaction and makes easier the input of local data. This program is useful for performing sensitivity analysis, siting studies and validation of model comparing the activity concentration output data with environmental monitoring data. The methodology of each module is described as well as the output data. (author)

  15. Assessment of internal doses in emergency situations

    Energy Technology Data Exchange (ETDEWEB)

    Rahola, T.; Muikku, M. [Radiation and Nuclear Safety Authority - STUK (Finland); Falk, R.; Johansson, J. [Swedish Radiation Protection Authority - SSI (Sweden); Liland, A.; Thorshaug, S. [NRPA (Norway)

    2006-04-15

    The need for assessing internal radiation doses in emergency situations was demonstrated after accidents in Brazil, Ukraine and other countries. Lately more and more concern has been expressed regarding malevolent use of radiation and radioactive materials. The scenarios for such use are more difficult to predict than for nuclear power plant or weapons accidents. Much of the results of the work done in the IRADES project can be adopted for use in various accidental situations involving radionuclides that are not addressed in this report. If an emergency situation occurs in only one or a few of the Nordic countries, experts from the other countries could be called upon to assist in monitoring. A big advantage is then our common platform. In the Nordic countries much work has been put down on quality assurance of measurements and on training of dose assessment calculations. Attention to this was addressed at the internal dosimetry course in October 2005. Nordic emergency preparedness exercises have so far not included training of direct measurements of people in the early phase of an emergency. The aim of the IRADES project was to improve the preparedness especially for thyroid measurements. The modest financial support did not enable the participants to make big efforts but certainly acted as a much appreciated reminder of the importance of being prepared also to handle situations with malevolent use of radioactive materials. It was left to each country to decide to which extent to improve the practical skills. There is still a need for detailed national implementation plans. Measurement strategies need to be developed in each country separately taking into account national regulations, local circumstances and resources. End users of the IRADES report are the radiation protection authorities. (au)

  16. Assessment of internal doses in emergency situations

    International Nuclear Information System (INIS)

    Rahola, T.; Muikku, M.; Falk, R.; Johansson, J.; Liland, A.; Thorshaug, S.

    2006-04-01

    The need for assessing internal radiation doses in emergency situations was demonstrated after accidents in Brazil, Ukraine and other countries. Lately more and more concern has been expressed regarding malevolent use of radiation and radioactive materials. The scenarios for such use are more difficult to predict than for nuclear power plant or weapons accidents. Much of the results of the work done in the IRADES project can be adopted for use in various accidental situations involving radionuclides that are not addressed in this report. If an emergency situation occurs in only one or a few of the Nordic countries, experts from the other countries could be called upon to assist in monitoring. A big advantage is then our common platform. In the Nordic countries much work has been put down on quality assurance of measurements and on training of dose assessment calculations. Attention to this was addressed at the internal dosimetry course in October 2005. Nordic emergency preparedness exercises have so far not included training of direct measurements of people in the early phase of an emergency. The aim of the IRADES project was to improve the preparedness especially for thyroid measurements. The modest financial support did not enable the participants to make big efforts but certainly acted as a much appreciated reminder of the importance of being prepared also to handle situations with malevolent use of radioactive materials. It was left to each country to decide to which extent to improve the practical skills. There is still a need for detailed national implementation plans. Measurement strategies need to be developed in each country separately taking into account national regulations, local circumstances and resources. End users of the IRADES report are the radiation protection authorities. (au)

  17. Nonsurgical Fluoroscopically Guided Dacryocystoplasty of Common Canalicular Obstructions

    Energy Technology Data Exchange (ETDEWEB)

    Wilhelm, Kai E; Hofer, Ulrich; Textor, Hans J [Department of Radiology, University Hospital Bonn, Sigmund-Freud-Strasse 25, D-53127 Bonn (Germany); Boeker, Thorsten [Department of Ophthalmology, University Hospital Bonn, Sigmund-Freud-Strasse 25, D-53127 Bonn (Germany); Strunk, Holger; Schild, Hans H [Department of Radiology, University Hospital Bonn, Sigmund-Freud-Strasse 25, D-53127 Bonn (Germany)

    2000-01-15

    Purpose: To assess dacryocystoplasty in the treatment of epiphora due to obstructions of the common canaliculus.Methods: Twenty patients with severe epiphora due to partial (n = 16) or complete (n = 4) obstruction of the common canaliculus underwent fluoroscopically guided dacryocystoplasty. In all cases of incomplete obstruction balloon dilation was performed. Stent implantation was attempted in cases with complete obstruction. Dacryocystography and clinical follow-up was performed at intervals of 1 week, and 3, 6, 12, and 18 months after the procedure. The mean follow-up was 6 months (range 3-18 months).Results: Balloon dilation was technically successfully performed in all patients with incomplete obstructions (n = 16). In three of four patients with complete obstruction stent implantation was performed successfully. Subsequent to failure of stent implantation in one of these patients balloon dilation was performed instead. The long-term primary patency rate in patients with incomplete obstructions was 88% (n = 14/16). In three of four cases with complete obstruction long-term patency was achieved during follow-up. Severe complications, infections, or punctal splitting were not observed.Conclusion: Fluoroscopically guided balloon dacryocystoplasty is a feasible nonsurgical therapy in canalicular obstructions with good clinical results that may be used as an alternative to surgical procedures. In patients with complete obstructions stent placement is possible but further investigations are needed to assess the procedural and long-term results.

  18. Nonsurgical Fluoroscopically Guided Dacryocystoplasty of Common Canalicular Obstructions

    International Nuclear Information System (INIS)

    Wilhelm, Kai E.; Hofer, Ulrich; Textor, Hans J.; Boeker, Thorsten; Strunk, Holger; Schild, Hans H.

    2000-01-01

    Purpose: To assess dacryocystoplasty in the treatment of epiphora due to obstructions of the common canaliculus.Methods: Twenty patients with severe epiphora due to partial (n = 16) or complete (n = 4) obstruction of the common canaliculus underwent fluoroscopically guided dacryocystoplasty. In all cases of incomplete obstruction balloon dilation was performed. Stent implantation was attempted in cases with complete obstruction. Dacryocystography and clinical follow-up was performed at intervals of 1 week, and 3, 6, 12, and 18 months after the procedure. The mean follow-up was 6 months (range 3-18 months).Results: Balloon dilation was technically successfully performed in all patients with incomplete obstructions (n = 16). In three of four patients with complete obstruction stent implantation was performed successfully. Subsequent to failure of stent implantation in one of these patients balloon dilation was performed instead. The long-term primary patency rate in patients with incomplete obstructions was 88% (n = 14/16). In three of four cases with complete obstruction long-term patency was achieved during follow-up. Severe complications, infections, or punctal splitting were not observed.Conclusion: Fluoroscopically guided balloon dacryocystoplasty is a feasible nonsurgical therapy in canalicular obstructions with good clinical results that may be used as an alternative to surgical procedures. In patients with complete obstructions stent placement is possible but further investigations are needed to assess the procedural and long-term results

  19. A radiological dose assessment for the Port Hope conversion facility

    International Nuclear Information System (INIS)

    Garisto, N.C.; Cooper, F.; Janes, A.; Stager, R.; Peters, R.

    2011-01-01

    The Port Hope Conversion Facility (PHCF) receives uranium trioxide for conversion to uranium hexafluoride (UF 6 ) or uranium dioxide (UO 2 ). The PHCF Site has a long history of industrial use. A Radiological Dose Assessment was undertaken as part of a Site Wide Risk Assessment. This assessment took into account all possible human receptors, both workers and members of the public. This paper focuses on a radiological assessment of dose to members of the public. The doses to members of the public from terrestrial pathways were added to the doses from aquatic pathways to obtain overall dose to receptors. The benchmark used in the assessment is 1 mSv/y. The estimated doses related to PHCF operations are much lower than the dose limit. (author)

  20. Dose assessments in nuclear power plant siting

    International Nuclear Information System (INIS)

    1988-03-01

    This document is mainly intended to provide information on dose estimations and assessments for the purpose of nuclear power plant (NPP) siting. It is not aimed at giving radiation protection guidance, criteria or procedures to be applied during the process of NPP siting nor even to provide recommendations on this subject matter. The document may however be of help for implementing some of the Nuclear Safety Standards (NUSS) documents on siting. The document was prepared before April 26, 1986, when a severe accident at the Unit 4 of Chernobyl NPP in the USSR had occurred. It should be emphasized that this document does not bridge the gap which exists in the NUSS programme as far as radiation protection guidance for the specific case of siting of NPP is concerned. The Agency will continue to work on this subject with the aim to prepare a safety series document on radiation protection requirements for NPP siting. This document could serve as a working document for this purpose. Refs, figs and tabs

  1. Fluoroscopic screen which is optically homogeneous

    International Nuclear Information System (INIS)

    1975-01-01

    A high efficiency fluoroscopic screen for X-ray examination consists of an optically homogeneous crystal plate of fluorescent material such as activated cesium iodide, supported on a transparent protective plate, with the edges of the assembly beveled and optically coupled to a light absorbing compound. The product is dressed to the desired thickness and provided with an X-ray-transparent light-opaque cover. (Auth.)

  2. Radiation exposure from shoe-fitting fluoroscopes

    International Nuclear Information System (INIS)

    Busch, Uwe

    2015-01-01

    It is 40 years ago that a very popular X-ray device disappeared in German shoe shops: the shoe-fitting fluoroscope or Pedoskop. Since the 1930s, these X-ray machines were an integral part of any good shoe business. Following the entry into force X-Ray Regulation (RoeV 1973) the use of these devices was prohibited in Germany.

  3. Evaluation of the UF/NCI hybrid computational phantoms for use in organ dosimetry of pediatric patients undergoing fluoroscopically guided cardiac procedures

    Science.gov (United States)

    Marshall, Emily L.; Borrego, David; Tran, Trung; Fudge, James C.; Bolch, Wesley E.

    2018-03-01

    Epidemiologic data demonstrate that pediatric patients face a higher relative risk of radiation induced cancers than their adult counterparts at equivalent exposures. Infants and children with congenital heart defects are a critical patient population exposed to ionizing radiation during life-saving procedures. These patients will likely incur numerous procedures throughout their lifespan, each time increasing their cumulative radiation absorbed dose. As continued improvements in long-term prognosis of congenital heart defect patients is achieved, a better understanding of organ radiation dose following treatment becomes increasingly vital. Dosimetry of these patients can be accomplished using Monte Carlo radiation transport simulations, coupled with modern anatomical patient models. The aim of this study was to evaluate the performance of the University of Florida/National Cancer Institute (UF/NCI) pediatric hybrid computational phantom library for organ dose assessment of patients that have undergone fluoroscopically guided cardiac catheterizations. In this study, two types of simulations were modeled. A dose assessment was performed on 29 patient-specific voxel phantoms (taken as representing the patient’s true anatomy), height/weight-matched hybrid library phantoms, and age-matched reference phantoms. Two exposure studies were conducted for each phantom type. First, a parametric study was constructed by the attending pediatric interventional cardiologist at the University of Florida to model the range of parameters seen clinically. Second, four clinical cardiac procedures were simulated based upon internal logfiles captured by a Toshiba Infinix-i Cardiac Bi-Plane fluoroscopic unit. Performance of the phantom library was quantified by computing both the percent difference in individual organ doses, as well as the organ dose root mean square values for overall phantom assessment between the matched phantoms (UF/NCI library or reference) and the patient

  4. Assessment of a new p-Mosfet usable as a dose rate insensitive gamma dose sensor

    International Nuclear Information System (INIS)

    Vettese, F.; Donichak, C.; Bourgeault, P.

    1995-01-01

    Dosimetric response of unbiased MOS devices has been assessed at dose rates greater than 2000 cGy/h. Application have been made to a personal dosemeter / dose rate meter to measure the absorbed tissue dose received in the case of acute external irradiation. (D.L.)

  5. Program for rapid dose assessment in criticality accident, RADAPAS

    International Nuclear Information System (INIS)

    Takahashi, Fumiaki

    2006-09-01

    In a criticality accident, a person near fissile material can receive extremely high dose which can cause acute health effect. For such a case, medical treatment should be carried out for the exposed person, according to severity of the exposure. Then, radiation dose should be rapidly assessed soon after an outbreak of an accident. Dose assessment based upon the quantity of induced 24 Na in human body through neutron exposure is expected as one of useful dosimetry techniques in a criticality accident. A dose assessment program, called RADAPAS (RApid Dose Assessment Program from Activated Sodium in Criticality Accidents), was therefore developed to assess rapidly radiation dose to exposed persons from activity of induced 24 Na. RADAPAS consists of two parts; one is a database part and the other is a part for execution of dose calculation. The database contains data compendiums of energy spectra and dose conversion coefficients from specific activity of 24 Na induced in human body, which had been derived in a previous analysis using Monte Carlo calculation code. Information for criticality configuration or characteristics of radiation in the accident field is to be interactively given with interface displays in the dose calculation. RADAPAS can rapidly derive radiation dose to the exposed person from the given information and measured 24 Na specific activity by using the conversion coefficient in database. This report describes data for dose conversions and dose calculation in RADAPAS and explains how to use the program. (author)

  6. Population dose assessment from radiodiagnosis in Portugal

    International Nuclear Information System (INIS)

    Serro, R.; Carreiro, J.V.; Galvao, J.P.; Reis, R.

    1992-01-01

    A survey of radiodiagnostic installations was carried out in Portugal covering 75 premises including public hospitals, local and regional public health centres. A total of 175 X ray tubes was surveyed using the new NEXT methodology covering data on premises, tube and operator, and projection. Average value of voltage, current-time product, HVL, ratio of beam area to film area and source to film distance for the eleven most frequent projections are reported as well as the skin entrance exposure and the doses to some organs. The weighted average dose values per projection and for the different organs allowed an estimate of the whole-body dose per caput. From the gonadal doses the genetic significant dose was also estimated

  7. Radiation dose assessment in nuclear medicine

    International Nuclear Information System (INIS)

    Stabin, M.G.

    2002-01-01

    In any application involving the use of ionizing radiation in humans, risks and benefits must be properly evaluated and balanced. Radionuclides are used in nuclear medicine in a variety of diagnostic and therapeutic procedures. Recently, interest has grown in therapeutic agents for a number of applications in nuclear medicine, particularly in the treatment of hematologic and non-hematologic malignancies. This has heightened interest in the need for radiation dose calculations and challenged the scientific community to develop more patient-specific and relevant dose models. Consideration of radiation dose in such studies is central to efforts to maximize dose to tumor while sparing normal tissues. In many applications, a significant absorbed dose may be received by some radiosensitive organs, particularly the active marrow. This talk will review the methods and models used in internal dosimetry in nuclear medicine, and discuss some current trends and challenges in this field

  8. Pre-procedural scout radiographs are unnecessary for routine pediatric fluoroscopic examinations

    Energy Technology Data Exchange (ETDEWEB)

    Creeden, Sean G.; Rao, Anil G.; Eklund, Meryle J.; Hill, Jeanne G.; Thacker, Paul G. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States)

    2017-03-15

    Although practice patterns vary, scout radiographs are often routinely performed with pediatric fluoroscopic studies. However few studies have evaluated their utility in routine pediatric fluoroscopy. To evaluate the value of scout abdomen radiographs in routine barium or water-soluble enema, upper gastrointestinal (GI) series, and voiding cystourethrogram pediatric fluoroscopic procedures. We retrospectively evaluated 723 barium or water-soluble enema, upper GI series, and voiding cystourethrogram fluoroscopic procedures performed at our institution. We assessed patient history and demographics, clinical indication for the examination, prior imaging findings and impressions, scout radiograph findings, additional findings provided by the scout radiograph that were previously unknown, and whether the scout radiograph contributed any findings that significantly changed management. We retrospectively evaluated 723 fluoroscopic studies (368 males and 355 females) in pediatric patients. Of these, 700 (96.8%) had a preliminary scout radiograph. Twenty-three (3.2%) had a same-day radiograph substituted as a scout radiograph. Preliminary scout abdomen radiographs/same-day radiographs showed no new significant findings in 719 (99.4%) studies. New but clinically insignificant findings were seen in 4 (0.6%) studies and included umbilical hernia, inguinal hernia and hip dysplasia. No findings were found on the scout radiographs that would either alter the examination performed or change management with regard to the exam. Pre-procedural scout abdomen radiographs are unnecessary in routine barium and water-soluble enema, upper GI series, and voiding cystourethrogram pediatric fluoroscopic procedures and can be substituted with a spot fluoroscopic last-image hold. (orig.)

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

    CERN Document Server

    Tapiovaara, M

    2003-01-01

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

  10. Use of guiding sheaths in peroral fluoroscopic gastroduodenal stent placement

    International Nuclear Information System (INIS)

    Bae, Jae-Ik; Shin, Ji Hoon; Song, Ho-Young; Yoon, Chang Jin; Nam, Deok Ho; Choi, Won-Chan; Lim, Jin-Oh

    2005-01-01

    Our purpose was to assess the safety and usefulness of guiding sheaths in peroral fluoroscopic gastroduodenal stent placement. Two types of guiding sheath were made from straight polytetrafluoroethylene tubes. Type A was 80 cm in length, 4 mm in outer diameter and 3 mm in inner diameter. Type B was 70 cm in length, 6 mm in outer diameter and 5 mm in inner diameter. The type A sheath was used in 18 patients in whom a catheter-guide wire combination failed to pass through a stricture. The type B sheath was used in 22 patients in whom a stent delivery system failed to pass through the stricture due to loop formation within the gastric lumen. The overall success rate for guiding a catheter-guide wire through a stricture after using the type A sheath was 89%. The overall success rate for passing a stent delivery system through a stricture after using the type B sheath was 100%. All procedures were tolerated by the patients without any significant complications. The guiding sheaths were safe and useful in peroral fluoroscopic gastroduodenal stent placement. (orig.)

  11. Dose assessment in pediatric computerized tomography

    International Nuclear Information System (INIS)

    Vilarinho, Luisa Maria Auredine Lima

    2004-01-01

    The objective of this work was the evaluation of radiation doses in paediatric computed tomography scans, considering the high doses usually involved and the absence of any previous evaluation in Brazil. Dose values were determined for skull and abdomen examinations, for different age ranges, by using the radiographic techniques routinely used in the clinical centers investigated. Measurements were done using pencil shape ionization chambers inserted in polymethylmethacrylate (PMMA) phantoms. These were compact phantoms of different diameters were specially designed and constructed for this work, which simulate different age ranges. Comparison of results with published values showed that doses were lower than the diagnostic reference levels established to adults exams by the European Commission. Nevertheless, doses in paediatric phantoms were higher than those obtained in adult phantoms. The paediatric dose values obtained in Hospitals A and B were lower than the reference level (DRL) adopted by SHIMPTON for different age ranges. In the range 0 - 0.5 year (neonatal), the values of DLP in Hospital B were 94 por cent superior to the DRL For the 10 years old children the values of CTDI w obtained were inferior in 89 por cent for skull and 83 por cent for abdomen examinations, compared to the values published by SHRIMPTON and WALL. Our measured CTDI w values were inferior to the values presented for SHRIMPTON and HUDA, for all the age ranges and types of examinations. It was observed that the normalized dose descriptors values in children in the neonatal range were always superior to the values of doses for the adult patient. In abdomen examinations, the difference was approximately 90% for the effective dose (E) and of 57%.for CTDI w . (author)

  12. Occupational dose assessment in interventional cardiology in Serbia

    International Nuclear Information System (INIS)

    Kaljevic, J.; Ciraj-Bjelac, O.; Stankovic, J.; Arandjic, D.; Bozovic, P.; Antic, V.

    2016-01-01

    The objective of this work is to assess the occupational dose in interventional cardiology in a large hospital in Belgrade, Serbia. A double-dosimetry method was applied for the estimation of whole-body dose, using thermoluminescent dosemeters, calibrated in terms of the personal dose equivalent H p (10). Besides the double-dosimetry method, eye dose was also estimated by means of measuring ambient dose equivalent, H*(10), and doses per procedure were reported. Doses were assessed for 13 physicians, 6 nurses and 10 radiographers, for 2 consequent years. The maximum annual effective dose assessed was 4.3, 2.1 and 1.3 mSv for physicians, nurses and radiographers, respectively. The maximum doses recorded by the dosemeter worn at the collar level (over the apron) were 16.8, 11.9 and 4.5 mSv, respectively. This value was used for the eye lens dose assessment. Estimated doses are in accordance with or higher than annual dose limits for the occupational exposure. (authors)

  13. Eye dose assessment and management: overview

    International Nuclear Information System (INIS)

    Rehani, M.M.

    2015-01-01

    Some publications have shown that Hp( 0.07 ) or even Hp( 10 ) can be used as good operational quantities for X-rays in view of difficulties with Hp( 3 ). With increasing awareness, there is tendency to use whatever dosimeter is available with correction factor to estimate eye lens dose. The best position for an eye lens dosimeter has been reported to be at the side of the head nearest to the radiation source, close to the eye. Recent studies have reported eye doses with cone beam CT (CBCT) both for patients and staff, and there are many papers reporting eye lens doses to staff in nuclear medicine. To minimise the dose to eyes, the user can take advantage of a feature of CBCT of projections acquired over an angular span of 1808 plus cone angle of the X-ray tube and with tube under scan arcs. (authors)

  14. Radionuclide transport and dose assessment modelling in biosphere assessment 2009

    International Nuclear Information System (INIS)

    Hjerpe, T.; Broed, R.

    2010-11-01

    Following the guidelines set forth by the Ministry of Trade and Industry (now Ministry of Employment and Economy), Posiva is preparing to submit a construction license application for the final disposal spent nuclear fuel at the Olkiluoto site, Finland, by the end of the year 2012. Disposal will take place in a geological repository implemented according to the KBS-3 method. The long-term safety section supporting the license application will be based on a safety case that, according to the internationally adopted definition, will be a compilation of the evidence, analyses and arguments that quantify and substantiate the safety and the level of expert confidence in the safety of the planned repository. This report documents in detail the conceptual and mathematical models and key data used in the landscape model set-up, radionuclide transport modelling, and radiological consequences analysis applied in the 2009 biosphere assessment. Resulting environmental activity concentrations in landscape model due to constant unit geosphere release rates, and the corresponding annual doses, are also calculated and presented in this report. This provides the basis for understanding the behaviour of the applied landscape model and subsequent dose calculations. (orig.)

  15. Microdosimetric approach for lung dose assessments

    International Nuclear Information System (INIS)

    Hofmann, W.; Steinhausler, F.; Pohl, E.; Bernroider, G.

    1980-01-01

    In the macroscopic region the term ''organ dose'' is related to an uniform energy deposition within a homogeneous biological target. Considering the lung, inhaled radioactive nuclides, however, show a significant non-uniform distribution pattern throughout the respiratory tract. For the calculation of deposition and clearance of inhaled alpha-emitting radionuclides within different regions of this organ, a detailed compartment model, based on the Weibel model A was developed. Since biological effects (e.g. lung cancer initiation) are primarily caused at the cellular level, the interaction of alpha particles with different types of cells of the lung tissue was studied. The basic approach is to superimpose alpha particle tracks on magnified images of randomly selected tissue slices, simulating alpha emitting sources. Particle tracks are generated by means of a specially developed computer program and used as input data for an on-line electronic image analyzer (Quantimet-720). Using adaptive pattern recognition methods the different cells in the lung tissue can be identified and their distribution within the whole organ determined. This microdosimetric method is applied to soluble radon decay products as well as to insoluble, highly localized, plutonium particles. For a defined microdistribution of alpha emitters, the resulting dose, integrated over all cellular dose values, is compared to the compartmental doses of the ICRP lung model. Furthermore this methodology is also applicable to other organs and tissues of the human body for dose calculations in practical health physics. (author)

  16. Assessment of radiation dose awareness among pediatricians

    International Nuclear Information System (INIS)

    Thomas, Karen E.; Parnell-Parmley, June E.; Charkot, Ellen; BenDavid, Guila; Krajewski, Connie; Haidar, Salwa; Moineddin, Rahim

    2006-01-01

    There is increasing awareness among pediatric radiologists of the potential risks associated with ionizing radiation in medical imaging. However, it is not known whether there has been a corresponding increase in awareness among pediatricians. To establish the level of awareness among pediatricians of the recent publicity on radiation risks in children, knowledge of the relative doses of radiological investigations, current practice regarding parent/patient discussions, and the sources of educational input. Multiple-choice survey. Of 220 respondents, 105 (48%) were aware of the 2001 American Journal of Roentgenology articles on pediatric CT and radiation, though only 6% were correct in their estimate of the quoted lifetime excess cancer risk associated with radiation doses equivalent to pediatric CT. A sustained or transient increase in parent questioning regarding radiation doses had been noticed by 31%. When estimating the effective doses of various pediatric radiological investigations in chest radiograph (CXR) equivalents, 87% of all responses (and 94% of CT estimates) were underestimates. Only 15% of respondents were familiar with the ALARA principle. Only 14% of pediatricians recalled any relevant formal teaching during their specialty training. The survey response rate was 40%. Awareness of radiation protection issues among pediatricians is generally low, with widespread underestimation of relative doses and risks. (orig.)

  17. Assessment of low absorbed dose with a MOSFET detector

    International Nuclear Information System (INIS)

    Butson, M.J.; Cancer Services, Wollongong, NSW; Cheung, T.; Yu, P.K.N.

    2004-01-01

    Full text: The ability of a MOSFET dosimetry system to measure low therapeutic doses has been evaluated for accuracy for high energy x-ray radiotherapy applications. The MOSFET system in high sensitivity mode produces a dose measurement reproducibility of within 10%, 4% and 2.5% for 2 cGy, 5 cGy and 10cGy dose assessment respectively. This is compared to 7%, 4% and 2% for an Attix parallel plate ionisation chamber and 20%, 7% and 3.5% for a Wellhofer IC4 small volume ionisation chamber. Results for our dose standard thimble ionisation chamber and low noise farmer dosemeter were 2%, 0.5% and 0.25% respectively for these measurements. The quoted accuracy of the MOSFET dosimetry system is partially due to the slight non linear dose response (reduced response) with age of the detector but mainly due to the intrinsic variations in measured voltage differential per applied dose. Results have shown that the MOSFET dosimetry system provides an adequate measure of dose at low dose levels and is comparable in accuracy to the Attix parallel plate ionisation chambers for relative dose assessment at levels of 2cGy to 10cGy. The use of the MOSFET dosimeter at low doses can extend the life expectancy of the device and may provide useful information for areas where low dose assessment is required. Copyright (2004) Australasian College of Physical Scientists and Engineers in Medicine

  18. Dose assessment for decontamination in Goiania

    International Nuclear Information System (INIS)

    Amaral, E.C.S.

    2000-01-01

    Shortly after the accident at Goiania, the need arose to set derived intervention levels for the various exposure pathways to guide and optimise clean up measures. For the members of the critical group an intervention level of 5 mSv for the total effective dose in the first year after the accident was chosen, which then was subdivided into values of 1 mSv due to the contribution of external irradiation indoors, 3 mSv from external irradiation while being outdoors, and 1 mSv due to incorporation of resuspended particles and ingestion of locally produced food. The clean up indoors could be directed such that a pre-described ambient dose rate was no longer exceeded. These exposure levels and effective doses to the critical groups predicted in 1988 are compared to actual measurements made in 1988 to 1993 in a local house near one primary contamination foci, and best estimate. It can be shown that the actual doses received by members of the public living in the affected areas were significantly lower. The various reasons for this overprediction will be discussed. (author)

  19. Fluoroscopic tomography. [for body section synthesis

    Science.gov (United States)

    Baily, N. A.; Crepeau, R. L.; Lasser, E. C.

    1974-01-01

    A fluoroscopic tomography system capable of synthesizing body sections at a number of levels within the body has been developed. The synthesized body sections may lie either in a range of planes parallel to, tilted with respect to, skewed with respect to, or both tilted and skewed with respect to the plane of motion of the X-ray tube target. In addition, body sections can be presented which are contoured to the patient's anatomy. That is to say, they may even encompass such complex surfaces as a quadratic hyperplane. In addition, tomograms of organs in motion can be imaged.

  20. Going beyond the most exposed people in a dose assessment

    Energy Technology Data Exchange (ETDEWEB)

    Hjerpe, Thomas; Broed, Robert [Facilia AB, Gustavslundsvaegen 151C, SE-167 51 Bromma (Sweden); Ikonen, Ari T.K. [Environmental Research and Assessment, EnviroCase, Ltd., Hallituskatu 1 D 4, FI-28 100 Pori (Finland)

    2014-07-01

    The dose assessment in a long-term radiation safety assessment often focus on assessing dose of a representative person to be used for determining compliance with a radiation dose constraint. This representative person is often assumed to receive a dose that is representative of the most exposed people, i.e., the more highly exposed individuals in the population. This is not always sufficient, the Finnish regulations for disposal of nuclear waste has radiation dose constraint to the most exposed people as well as for larger groups of exposed people. This work presents the methodology to assessing dose of a representative person for a larger group of exposed people as applied by Posiva in the TURVA-2012 safety case for the spent nuclear fuel disposal at Olkiluoto. In addition, annual doses from the set of biosphere calculation cases analysed in TURVA-2012 are presented and discussed. Special focus is given on explaining the differences in exposure levels and exposure routes between the estimated annual doses to representative persons for most exposed people and a larger exposed group. The results show that the annual doses to a larger group of people ranges from one to three orders of magnitude below the annual doses to the most exposed people. Furthermore, the exposure route related to food ingestion is less significant for the larger group of people compared to the most exposed people and that the exposure route related to water ingestion shows the opposite behaviour. (authors)

  1. A review of occupational dose assessment uncertainties and approaches

    International Nuclear Information System (INIS)

    Anderson, R. W.

    2004-01-01

    The Radiological Protection Practitioner (RPP) will spend a considerable proportion of his time predicting or assessing retrospective radiation exposures to occupational personnel for different purposes. The assessments can be for a variety of purposes, such as to predict doses for occupational dose control, or project design purposes or to make retrospective estimates for the dose record, or account for dosemeters which have been lost or damaged. There are other less frequent occasions when dose assessment will be required such as to support legal cases and compensation claims and to provide the detailed dose information for epidemiological studies. It is important that the level of detail, justification and supporting evidence in the dose assessment is suitable for the requirements. So for instance, day to day operational dose assessments often rely mainly on the knowledge of the RPP in discussion with operators whilst at the other end of the spectrum a historical dose assessment for a legal case will require substantial research and supporting evidence for the estimate to withstand forensic challenge. The robustness of the assessment will depend on many factors including a knowledge of the work activities, the radiation dose uptake and field characteristics; all of which are affected by factors such as the time elapsed, the memory of operators and the dosemeters employed. This paper reviews the various options and uncertainties in dose assessments ranging from use of personal dosimetry results to the development of upper bound assessments. The level of assessment, the extent of research and the evidence adduced should then be appropriate to the end use of the estimate. (Author)

  2. IAEA/IDEAS intercomparison exercise on internal dose assessment

    International Nuclear Information System (INIS)

    Doerfel, H.; Andrasi, A.; Cruz-Suarez, R.; Castellani, C. M.; Hurtgen, C.; Marsh, J.; Zeger, J.

    2007-01-01

    An Internet based intercomparison exercise on assessment of occupational exposure due to intakes of radionuclides has been performed to check the applicability of the 'General Guidelines for the Assessment of Internal Dose from Monitoring Data' developed by the IDEAS group. There were six intake cases presented on the Internet and 81 participants worldwide reported solutions to these cases. Results of the exercise indicate that the guidelines have a positive influence on the methodologies applied for dose assessments and, if correctly applied, improve the harmonisation of assessed doses. (authors)

  3. Personal monitoring and assessment of doses received by radiation workers

    International Nuclear Information System (INIS)

    Swindon, T.N.; Morris, N.D.

    1981-12-01

    The Personal Radiation Monitoring Service operated by the Australian Radiation Laboratory is outlined and the types of monitors used for assessment of doses received by radiation workers are described. The distribution of doses received by radiation workers in different occupational categories is determined. From these distributions, the average doses received have been assessed and the maximum likely additional increase in cancer deaths in Australia as a result of occupational exposure estimated. This increase is shown to be very small. There is, however, a considerable spread of doses received by individuals within occupational groups

  4. Iodine-129 Dose in LLW Disposal Facility Performance Assessments

    International Nuclear Information System (INIS)

    Wilhite, E.L.

    1999-01-01

    Iodine-129 has the lowest Performance Assessment derived inventory limit in SRS disposal facilities. Because iodine is concentrated in the body to one organ, the thyroid, it has been thought that dilution with stable iodine would reduce the dose effects of 129I.Examination of the dose model used to establish the Dose conversion factor for 129I shows that, at the levels considered in performance assessments of low-level waste disposal facilities, the calculated 129I dose already accounts for ingestion of stable iodine. At higher than normal iodine ingestion rates, the uptake of iodine by the thyroid itself decrease, which effectively cancels out the isotopic dilution effect

  5. An Internal Dose Assessment Associated with Personal Food Intake

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joeun; Jae, Moosung [Hanyang University, Seoul (Korea, Republic of); Hwang, Wontae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    ICRP (International Commission on Radiological Protection), Therefore, had recommended the concept of 'Critical Group'. Recently the ICRP has recommended the use of 'Representative Person' on the new basic recommendation 103. On the other hand the U.S. NRC (Nuclear Regulatory Commission) has adopted more conservative concept, 'Maximum Exposed Individuals (MEI)' of critical Group. The dose assessment in Korea is based on MEI. Although dose assessment based on MEI is easy to receive the permission of the regulatory authority, it is not efficient. Meanwhile, the internal dose by food consumption takes an important part. Therefore, in this study, the internal dose assessment was performed in accordance with ICRP's new recommendations. The internal dose assessment was performed in accordance with ICRP's new recommendations. It showed 13.2% decreased of the annual internal dose due to gaseous effluents by replacing MEI to the concept of representative person. Also, this calculation based on new ICRP's recommendation has to be extended to all areas of individual dose assessment. Then, more accurate and efficient values might be obtained for dose assessment.

  6. Characteristics of environmental gamma-rays and dose assessment

    International Nuclear Information System (INIS)

    Saito, Kimiaki; Moriuchi, Shigeru

    1986-01-01

    Environmental radioactivity has attracted much attention in terms of exposure to the population, although its exposure doses are minimal. This paper presents problems encountered in the assessment of exposure doses using model and monitoring systems, focusing on the characteristics, such as energy distribution, direction distribution, and site, of environmental gamma-rays. The assessment of outdoor and indoor exposure doses of natural gamma-rays is discussed in relation to the shielding effect of the human body. In the assessment of artificial gamma-rays, calculation of exposure doses using build-up factor, the shielding effect of the human body, and energy dependency of the measuring instrument are covered. A continuing elucidation about uncertainties in dose assessment is emphasized. (Namekawa, K.)

  7. Monitoring requirements for assessment of internal dose

    International Nuclear Information System (INIS)

    Eckerman, K.F.

    1985-01-01

    Data obtained by routine personnel monitoring is usually not a sufficient basis for estimation of dose. Collected data must be interpreted carefully and supplemented with appropriate information before reasonably accurate estimates of dose (i.e., accurate enough to indicate whether or nor personnel are exposed in excess of recommended limits) can be developed. When the exposure is of sufficient magnitude that a rather precise estimate of dose is needed, the health physicist will bring to bear on the problem other, more refined, methods of dosimetry. These might include a reconstruction of the incident and, for internal emitters, an extensive series of in vivo measurements or analyses of excreta. Thus, cases of special significance must often be evaluated using techniques and resources beyond those routinely employed. This is not a criticism of most routine monitoring programs. These programs are usually carefully designed in a manner commensurate with the degree of exposure routinely encountered and the requirement of a practical program of radiation protection. 10 refs

  8. SU-F-I-76: Fluoroscopic X-Ray Beam Profiles for Spectra Incorporating Copper Filtration

    Energy Technology Data Exchange (ETDEWEB)

    Wunderle, K [Cleveland Clinic Foundation, Cleveland, OH (United States); Wayne State University School of Medicine, Detroit, MI (United States); Godley, A; Shen, Z; Dong, F [Cleveland Clinic Foundation, Cleveland, OH (United States); Rakowski, J [Wayne State University School of Medicine, Detroit, MI (United States)

    2016-06-15

    Purpose: The purpose of this investigation is to characterize and quantify X-ray beam profiles for fluoroscopic x-ray beam spectra incorporating spectral (copper) filtration. Methods: A PTW (Freiburg, Germany) type 60016 silicon diode detector and PTW MP3 water tank were used to measure X-ray beam profiles for 60, 80, 100 and 120 kVp x-ray beams at five different copper filtration thicknesses ranging from 0–0.9 mm at 22 and 42 cm fields of view and depths of 1, 5, and 10 cm in both the anode-cathode axis (inplane) and cross-plane directions. All measurements were acquired on a Siemens (Erlangen, Germany) Artis ZeeGo fluoroscope inverted from the typical orientation providing an x-ray beam originating from above the water surface with the water level set at 60 cm from the focal spot. Results: X-ray beam profiles for beam spectra without copper filtration compared well to previously published data by Fetterly et al. [Med Phys, 28, 205 (2001)]. Our data collection benefited from the geometric orientation of the fluoroscope, providing a beam perpendicular to the tank water surface, rather than through a thin side wall as did the previously mentioned study. Profiles for beams with copper filtration were obtained which have not been previously investigated and published. Beam profiles in the anode-cathode axis near the surface and at lower x-ray energy exhibited substantial heel effect, which became less pronounced at greater depth. At higher energy with copper filtration in the beam, the dose falloff out-of-field became less pronounced, as would be anticipated given higher scatter photon energy. Conclusion: The x-ray beam profile data for the fluoroscopic x-ray beams incorporating copper filtration are intended for use as reference data for estimating doses to organs or soft tissue, including fetal dose, involving similar beam qualities or for comparison with mathematical models.

  9. Comparison of conventional full spine radiographs and fluoroscopic scanning method in young patients with idiopathic scoliosis; Vergleich von konventioneller Wirbelsaeulenganzaufnahme und fluoroskopischer Scan-Methode bei jungen Patienten mit idiopathischer Skoliose

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, J.; Kottke, R.; Claussen, C. [Abt. fuer Radiologische Diagnostik, Universitaetsklinikum Tuebingen (Germany); Kluba, T.; Niemeyer, T.; Hahnfeldt, T. [Klinik und Poliklinik fuer Orthopaedie, Universitaetsklinikum Tuebingen (Germany); Vonthein, R. [Inst. fuer Medizinische Biometrie, Universitaetsklinikum Tuebingen (Germany); Kamm, K.F. [Philips Medizin Systeme GmbH, Hamburg (Germany)

    2005-08-01

    Purpose: evaluation of low-dose full spine radiographs using fluoroscopic images for the assessment of the Cobb angle measurement in patients with scoliosis. Material and methods: twenty-one consecutive patients (aged 10-27 years, mean age 14 years) with a conventional full spine examination (film speed class 800) underwent a follow-up exam using digital pulsed fluoroscopy (Multi Diagnost 4, Philips Medical Systems, Eindhoven, The Netherlands). The mean follow-up was 9 months. During a synchronized scan with a C-arm speed of 4 cm/sec fluoroscopic images were stored with a pulsed frequency of 3 images per second. The single images were merged and reconstructed to one image with the software easy spine (Philips medical Systems, Eindhoven, The Netherlands). The corresponding dose-area product values (DAP) of both methods were compared. Three independent observers assessed Cobb angles and image quality for each technique. Results: the mean DAP values for conventional imaging was 94.9 cGy x cm{sup 2} and for fluoroscopy 7.8 cGy x cm{sup 2}, respectively. A significant dose reduction of 91.8% (CI 91% to 95%) was calculated. The average absolute angle difference between the observers was found to be 2.7 for conventional imaging and 2.4 for the fluoroscopic method. Interobserver standard deviation of 2.9 was lower than the 5.3 for conventional images. Image quality was better in the conventional images. Conclusion: using the scanning method, we could achieve a mean reduction of the radiation dose of 92%, while the accuracy of the Cobb angle measurements was comparable for both techniques despite of reduced image quality of digital fluoroscopy. (orig.)

  10. Exposition of the operator's eye lens and efficacy of radiation shielding in fluoroscopically guided interventions

    International Nuclear Information System (INIS)

    Galster, M.; Adamus, R.; Guhl, C.; Uder, M.

    2013-01-01

    Purpose: Efficacy of radiation protection tools for the eye lens dose of the radiologist in fluoroscopic interventions. Materials and Methods: A patient phantom was exposed using a fluoroscopic system. Dose measurements were made at the eye location of the radiologist using an ionization chamber. The setting followed typical fluoroscopic interventions. The reduction of scattered radiation by the equipment-mounted shielding (undercouch drapes and overcouch top) was evaluated. The ceiling-suspended lead acrylic glass screen was tested in scattered radiation generated by a slab phantom. The protective properties of different lead glass goggles and lead acrylic visors were evaluated by thermoluminescence measurements on a head phantom in the primary beam. Results: The exposition of the lens of about 110 to 550 μSv during radiologic interventions is only slightly reduced by the undercouch drapes. Applying the top in addition to the drapes reduces the lens dose by a factor of 2 for PA projections. In 25 LAO the dose is reduced by a factor between 1.2 and 5. The highest doses were measured for AP angulations furthermore the efficacy of the equipment-mounted shielding is minimal. The ceiling-suspended lead screen reduced scatter by a factor of about 30. The lead glass goggles and visors reduced the lens dose up to a factor of 8 to 10. Depending on the specific design, the tested models are less effective especially for radiation from lateral with cranial angulation of the beam. Occasionally the visors even caused an increase of dose. Conclusion: The exposition of the eye lens can be kept below the new occupational limit recommended by the ICRP if the radiation shielding equipment is used consistently. (orig.)

  11. [Exposition of the operator's eye lens and efficacy of radiation shielding in fluoroscopically guided interventions].

    Science.gov (United States)

    Galster, M; Guhl, C; Uder, M; Adamus, R

    2013-05-01

    Efficacy of radiation protection tools for the eye lens dose of the radiologist in fluoroscopic interventions. A patient phantom was exposed using a fluoroscopic system. Dose measurements were made at the eye location of the radiologist using an ionization chamber. The setting followed typical fluoroscopic interventions. The reduction of scattered radiation by the equipment-mounted shielding (undercouch drapes and overcouch top) was evaluated. The ceiling-suspended lead acrylic glass screen was tested in scattered radiation generated by a slab phantom. The protective properties of different lead glass goggles and lead acrylic visors were evaluated by thermoluminescence measurements on a head phantom in the primary beam. The exposition of the lens of about 110 to 550 μSv during radiologic interventions is only slightly reduced by the undercouch drapes. Applying the top in addition to the drapes reduces the lens dose by a factor of 2 for PA projections. In 25°LAO the dose is reduced by a factor between 1.2 and 5. The highest doses were measured for AP angulations furthermore the efficacy of the equipment-mounted shielding is minimal. The ceiling-suspended lead screen reduced scatter by a factor of about 30. The lead glass goggles and visors reduced the lens dose up to a factor of 8 to 10. Depending on the specific design, the tested models are less effective especially for radiation from lateral with cranial angulation of the beam. Occasionally the visors even caused an increase of dose. The exposition of the eye lens can be kept below the new occupational limit recommended by the ICRP if the radiation shielding equipment is used consistently. © Georg Thieme Verlag KG Stuttgart · New York.

  12. Occupational exposures during abdominal fluoroscopically guided interventional procedures for different patient sizes - A Monte Carlo approach.

    Science.gov (United States)

    Santos, William S; Belinato, Walmir; Perini, Ana P; Caldas, Linda V E; Galeano, Diego C; Santos, Carla J; Neves, Lucio P

    2018-01-01

    In this study we evaluated the occupational exposures during an abdominal fluoroscopically guided interventional radiology procedure. We investigated the relation between the Body Mass Index (BMI), of the patient, and the conversion coefficient values (CC) for a set of dosimetric quantities, used to assess the exposure risks of medical radiation workers. The study was performed using a set of male and female virtual anthropomorphic phantoms, of different body weights and sizes. In addition to these phantoms, a female and a male phantom, named FASH3 and MASH3 (reference virtual anthropomorphic phantoms), were also used to represent the medical radiation workers. The CC values, obtained as a function of the dose area product, were calculated for 87 exposure scenarios. In each exposure scenario, three phantoms, implemented in the MCNPX 2.7.0 code, were simultaneously used. These phantoms were utilized to represent a patient and medical radiation workers. The results showed that increasing the BMI of the patient, adjusted for each patient protocol, the CC values for medical radiation workers decrease. It is important to note that these results were obtained with fixed exposure parameters. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  13. Fluoroscopically guided percutaneous jejunostomy: outcomes in 25 consecutive patients

    International Nuclear Information System (INIS)

    Yang, Z.Q.; Shin, J.H.; Song, H.-Y.; Kwon, J.H.; Kim, J.-W.; Kim, K.R.; Kim, J.-H.

    2007-01-01

    Aim: To assess the feasibility and safety of fluoroscopically guided percutaneous jejunostomy. Material and methods: Between May 1999 and August 2006 percutaneous jejunostomy was attempted in 25 patients. A 5 F vascular catheter (n = 20) or a 7.5 F multifunctional coil catheter (n = 5) was used to insufflate the jejunum. The distended jejunum was punctured using a 17 G needle (n = 19) or a 21 G Chiba needle (n = 6) with the inserted catheter as a target. A 12 or 14 F loop feeding tube was inserted after serial dilations. The technical success, complications, 30-day mortality, and in-dwelling period of the feeding tube placement were evaluated. Results: The technical success rate was 92% (23/25). Technical failures (n = 2) resulted from the inability to insufflate the jejunum secondary to failure to pass the catheter through a malignant stricture at the oesophagojejunostomy site and thus subsequent puncture of the undistended jejunum failed, or failure to introduce the Neff catheter into the jejunum. Pericatheter leakage with pneumoperitoneum was a complication in three patients (12%) and was treated conservatively. The 30-day mortality was 13% (3/23); however, there was no evidence that these deaths were attributed to the procedure. Except for four patients who were lost to follow-up and two failed cases, 15 of the 19 jejunostomy catheters were removed because of patient death (n = 12) or completion of treatment (n = 3), with a mean and median in-dwelling period of 231 and 87 days, respectively. Conclusions: Fluoroscopically guided percutaneous jejunostomy is a feasible procedure with a high technical success and a low complication rate. In addition to a 17 G needle, a 21 G needle can safely be used to puncture the jejunum

  14. A real-time internal dose assessment exercise

    International Nuclear Information System (INIS)

    Bingham, D.; Bull, R. K.

    2013-01-01

    A real-time internal dose assessment exercise has been conducted in which participants were required to make decisions about sampling requirements, seek relevant information about the 'incident' and make various interim dose assessments. At the end of the exercise, each participant was requested to make a formal assessment, providing statements of the methods, models and assumptions used in that assessment. In this paper we describe how the hypothetical assessment case was set up and the exercise was conducted, the responses of the participants and the assessments of dose that they made. Finally we discuss the lessons learnt from the exercise and suggest how the exercise may be adapted to a wider range of participants. (authors)

  15. Nonparametric estimation of benchmark doses in environmental risk assessment

    Science.gov (United States)

    Piegorsch, Walter W.; Xiong, Hui; Bhattacharya, Rabi N.; Lin, Lizhen

    2013-01-01

    Summary An important statistical objective in environmental risk analysis is estimation of minimum exposure levels, called benchmark doses (BMDs), that induce a pre-specified benchmark response in a dose-response experiment. In such settings, representations of the risk are traditionally based on a parametric dose-response model. It is a well-known concern, however, that if the chosen parametric form is misspecified, inaccurate and possibly unsafe low-dose inferences can result. We apply a nonparametric approach for calculating benchmark doses, based on an isotonic regression method for dose-response estimation with quantal-response data (Bhattacharya and Kong, 2007). We determine the large-sample properties of the estimator, develop bootstrap-based confidence limits on the BMDs, and explore the confidence limits’ small-sample properties via a short simulation study. An example from cancer risk assessment illustrates the calculations. PMID:23914133

  16. The system of radiation dose assessment and dose conversion coefficients in the ICRP and FGR

    Energy Technology Data Exchange (ETDEWEB)

    Kim, So Ra; Min, Byung Il; Park, Kihyun; Yang, Byung Mo; Suh, Kyung Suk [Nuclear Environmental Safety Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-12-15

    The International Commission on Radiological Protection (ICRP) recommendations and the Federal Guidance Report (FGR) published by the U.S. Environmental Protection Agency (EPA) have been widely applied worldwide in the fields of radiation protection and dose assessment. The dose conversion coefficients of the ICRP and FGR are widely used for assessing exposure doses. However, before the coefficients are used, the user must thoroughly understand the derivation process of the coefficients to ensure that they are used appropriately in the evaluation. The ICRP provides recommendations to regulatory and advisory agencies, mainly in the form of guidance on the fundamental principles on which appropriate radiological protection can be based. The FGR provides federal and state agencies with technical information to assist their implementation of radiation protection programs for the U.S. population. The system of radiation dose assessment and dose conversion coefficients in the ICRP and FGR is reviewed in this study. A thorough understanding of their background is essential for the proper use of dose conversion coefficients. The FGR dose assessment system was strongly influenced by the ICRP and the U.S. National Council on Radiation Protection and Measurements (NCRP), and is hence consistent with those recommendations. Moreover, the ICRP and FGR both used the scientific data reported by Biological Effects of Ionizing Radiation (BEIR) and United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) as their primary source of information. The difference between the ICRP and FGR lies in the fact that the ICRP utilized information regarding a population of diverse races, whereas the FGR utilized data on the American population, as its goal was to provide guidelines for radiological protection in the US. The contents of this study are expected to be utilized as basic research material in the areas of radiation protection and dose assessment.

  17. The system of radiation dose assessment and dose conversion coefficients in the ICRP and FGR

    International Nuclear Information System (INIS)

    Kim, So Ra; Min, Byung Il; Park, Kihyun; Yang, Byung Mo; Suh, Kyung Suk

    2016-01-01

    The International Commission on Radiological Protection (ICRP) recommendations and the Federal Guidance Report (FGR) published by the U.S. Environmental Protection Agency (EPA) have been widely applied worldwide in the fields of radiation protection and dose assessment. The dose conversion coefficients of the ICRP and FGR are widely used for assessing exposure doses. However, before the coefficients are used, the user must thoroughly understand the derivation process of the coefficients to ensure that they are used appropriately in the evaluation. The ICRP provides recommendations to regulatory and advisory agencies, mainly in the form of guidance on the fundamental principles on which appropriate radiological protection can be based. The FGR provides federal and state agencies with technical information to assist their implementation of radiation protection programs for the U.S. population. The system of radiation dose assessment and dose conversion coefficients in the ICRP and FGR is reviewed in this study. A thorough understanding of their background is essential for the proper use of dose conversion coefficients. The FGR dose assessment system was strongly influenced by the ICRP and the U.S. National Council on Radiation Protection and Measurements (NCRP), and is hence consistent with those recommendations. Moreover, the ICRP and FGR both used the scientific data reported by Biological Effects of Ionizing Radiation (BEIR) and United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) as their primary source of information. The difference between the ICRP and FGR lies in the fact that the ICRP utilized information regarding a population of diverse races, whereas the FGR utilized data on the American population, as its goal was to provide guidelines for radiological protection in the US. The contents of this study are expected to be utilized as basic research material in the areas of radiation protection and dose assessment

  18. Interactive Rapid Dose Assessment Model (IRDAM): user's guide

    International Nuclear Information System (INIS)

    Poeton, R.W.; Moeller, M.P.; Laughlin, G.J.; Desrosiers, A.E.

    1983-05-01

    As part of the continuing emphasis on emergency preparedness the US Nuclear Regulatory Commission (NRC) sponsored the development of a rapid dose assessment system by Pacific Northwest Laboratory (PNL). This system, the Interactive Rapid Dose Assessment Model (IRDAM) is a micro-computer based program for rapidly assessing the radiological impact of accidents at nuclear power plants. This User's Guide provides instruction in the setup and operation of the equipment necessary to run IRDAM. Instructions are also given on how to load the magnetic disks and access the interactive part of the program. Two other companion volumes to this one provide additional information on IRDAM. Reactor Accident Assessment Methods (NUREG/CR-3012, Volume 2) describes the technical bases for IRDAM including methods, models and assumptions used in calculations. Scenarios for Comparing Dose Assessment Models (NUREG/CR-3012, Volume 3) provides the results of calculations made by IRDAM and other models for specific accident scenarios

  19. Dose assessment activities in the Republic of the Marshall Islands

    International Nuclear Information System (INIS)

    Simon, S.L.; Graham, J.C.

    1996-01-01

    Dose assessments, both retrospective and prospective, comprise one important function of a radiological study commissioned by the Republic of the Marshall Islands (RMI) government in late 1989. Estimating past or future exposure requires the synthesis of information from historical data, results from a recently completed field monitoring program, laboratory measurements, and some experimental studies. Most of the activities in the RMI to date have emphasized a pragmatic rather than theoretical approach. In particular, most of the recent effort has been expended on conducting an independent radiological monitoring program to determine the degree of deposition and the geographical extent of weapons test fallout over the nation. Contamination levels on 70% of the land mass of the Marshall Islands were unknown prior to 1994. The environmental radioactivity data play an integral role in both retrospective and prospective assessments. One recent use of dose assessment has been to interpret environmental measurements of radioactivity into annual doses that might be expected at every atoll. A second use for dose assessment has been to determine compliance with dose action level for the rehabitation of Rongelap Island. Careful examination of exposure pathways relevant to the island lifestyle has been necessary to accommodate these purposes. Finally, an examination is underway of gummed film, fixed-instrument, and aerial survey data accumulated during the 1950's by the Health and Safety Laboratory of the U.S. AEC. This article gives an overview of these many different activities and a summary of recent dose assessments

  20. Epidemiological methods for assessing dose-response and dose-effect relationships

    DEFF Research Database (Denmark)

    Kjellström, Tord; Grandjean, Philippe

    2007-01-01

    Selected Molecular Mechanisms of Metal Toxicity and Carcinogenicity General Considerations of Dose-Effect and Dose-Response Relationships Interactions in Metal Toxicology Epidemiological Methods for Assessing Dose-Response and Dose-Effect Relationships Essential Metals: Assessing Risks from Deficiency......Description Handbook of the Toxicology of Metals is the standard reference work for physicians, toxicologists and engineers in the field of environmental and occupational health. This new edition is a comprehensive review of the effects on biological systems from metallic elements...... access to a broad range of basic toxicological data and also gives a general introduction to the toxicology of metallic compounds. Audience Toxicologists, physicians, and engineers in the fields of environmental and occupational health as well as libraries in these disciplines. Will also be a useful...

  1. Automated size-specific CT dose monitoring program: Assessing variability in CT dose

    International Nuclear Information System (INIS)

    Christianson, Olav; Li Xiang; Frush, Donald; Samei, Ehsan

    2012-01-01

    Purpose: The potential health risks associated with low levels of ionizing radiation have created a movement in the radiology community to optimize computed tomography (CT) imaging protocols to use the lowest radiation dose possible without compromising the diagnostic usefulness of the images. Despite efforts to use appropriate and consistent radiation doses, studies suggest that a great deal of variability in radiation dose exists both within and between institutions for CT imaging. In this context, the authors have developed an automated size-specific radiation dose monitoring program for CT and used this program to assess variability in size-adjusted effective dose from CT imaging. Methods: The authors radiation dose monitoring program operates on an independent health insurance portability and accountability act compliant dosimetry server. Digital imaging and communication in medicine routing software is used to isolate dose report screen captures and scout images for all incoming CT studies. Effective dose conversion factors (k-factors) are determined based on the protocol and optical character recognition is used to extract the CT dose index and dose-length product. The patient's thickness is obtained by applying an adaptive thresholding algorithm to the scout images and is used to calculate the size-adjusted effective dose (ED adj ). The radiation dose monitoring program was used to collect data on 6351 CT studies from three scanner models (GE Lightspeed Pro 16, GE Lightspeed VCT, and GE Definition CT750 HD) and two institutions over a one-month period and to analyze the variability in ED adj between scanner models and across institutions. Results: No significant difference was found between computer measurements of patient thickness and observer measurements (p= 0.17), and the average difference between the two methods was less than 4%. Applying the size correction resulted in ED adj that differed by up to 44% from effective dose estimates that were not

  2. Automated size-specific CT dose monitoring program: Assessing variability in CT dose

    Energy Technology Data Exchange (ETDEWEB)

    Christianson, Olav; Li Xiang; Frush, Donald; Samei, Ehsan [Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 and Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States) and Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Department of Physics, Duke University, Durham, North Carolina 27710 (United States); and Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 (United States)

    2012-11-15

    Purpose: The potential health risks associated with low levels of ionizing radiation have created a movement in the radiology community to optimize computed tomography (CT) imaging protocols to use the lowest radiation dose possible without compromising the diagnostic usefulness of the images. Despite efforts to use appropriate and consistent radiation doses, studies suggest that a great deal of variability in radiation dose exists both within and between institutions for CT imaging. In this context, the authors have developed an automated size-specific radiation dose monitoring program for CT and used this program to assess variability in size-adjusted effective dose from CT imaging. Methods: The authors radiation dose monitoring program operates on an independent health insurance portability and accountability act compliant dosimetry server. Digital imaging and communication in medicine routing software is used to isolate dose report screen captures and scout images for all incoming CT studies. Effective dose conversion factors (k-factors) are determined based on the protocol and optical character recognition is used to extract the CT dose index and dose-length product. The patient's thickness is obtained by applying an adaptive thresholding algorithm to the scout images and is used to calculate the size-adjusted effective dose (ED{sub adj}). The radiation dose monitoring program was used to collect data on 6351 CT studies from three scanner models (GE Lightspeed Pro 16, GE Lightspeed VCT, and GE Definition CT750 HD) and two institutions over a one-month period and to analyze the variability in ED{sub adj} between scanner models and across institutions. Results: No significant difference was found between computer measurements of patient thickness and observer measurements (p= 0.17), and the average difference between the two methods was less than 4%. Applying the size correction resulted in ED{sub adj} that differed by up to 44% from effective dose

  3. Re-assessment of dose from the Vinten extremity dosemeter

    International Nuclear Information System (INIS)

    O'Hagan, J.B.; Pearson, A.J.; Dutt, J.C.

    1989-01-01

    A procedure is described for re-assessing the dose from the Vinten extremity dosemeter using phototransferred thermoluminescence. The technique produces a linear response up to 50 Sv. The re-assessment efficiency is approximately 10% for the first re-assessment and 3-5% for the second re-assessment. The detection threshold values (at the 95% confidence level) are 3 mSv and 9 mSv respectively. (author)

  4. Assessment of concomitant testicular dose with radiochromic film

    International Nuclear Information System (INIS)

    Fricker, Katherine; Thompson, Christine; Meyer, Juergen

    2013-01-01

    To assess the suitability of EBT2 and XRQA2 Gafchromic film for measuring low doses in the periphery of treatment fields, and to measure the accumulative concomitant dose to the contralateral testis resulting from CT imaging, pre-treatment imaging (CBCT) and seminoma radiotherapy with and without gonadal shielding. Superficial peripheral dose measurements made using EBT2 Gafchromic film on the surface of water equivalent material were compared to measurements made with an ionisation chamber in a water phantom to evaluate the suitability and accuracy of the film dosimeter for such measurements. Similarly, XRQA2 was used to measure surface doses within a kilovoltage beam and compared with ionisation chamber measurements. Gafchromic film was used to measure CT, CBCT and seminoma treatment related testicular doses on an anthropomorphic phantom. Doses were assessed for two clinical plans, both with and without gonadal shielding. Testicular doses resulting from the treatment of up to 0.83 ± 0.17 Gy were measured per treatment. Additional doses of up to 0.49 ± 0.01 and 2.35 ± 0.05 cGy were measured per CBCT and CT image, respectively. Reductions in the testicular dose in the order of 10, 36 and 78 % were observed when gonadal shielding was fitted for treatment, CT and CBCT imaging, respectively. Gafchromic film was found to be suitable for measuring dose in the periphery of treatment fields. The dose to the testis should be limited to minimise the risk of radiation related side effects. This can be achieved by using appropriate gonadal shielding, irrespective of the treatment fields employed.

  5. Fluoroscopically-guided foam sclerotherapy with sodium morrhuate for the treatment of lower extremity varices

    International Nuclear Information System (INIS)

    Wang Haiting; Jiang Zhongpu; Zhou Yi

    2011-01-01

    Objective: To evaluate fluoroscopically-guided foam sclerotherapy with injection of domestic sodium morrhuate in treating lower extremity varices. Methods: A total of 30 cases (39 diseased lower limbs) with lower extremity varices were enrolled in this study. Under fluoroscopic guidance foam sclerotherapy with injection of domestic sodium morrhuate was carried out in all patients. The obstructed condition of the great saphenous vein was observed during the following three months. Results: The technical success was achieved in all 39 patients. The mean dose of foam sclerosant used for each diseased limb was 5.9 ml (3.4-8.2 ml). Disappearance of blood flow reflux in lower extremity vein immediately after the treatment was seen in 35 patients (90%). Three months after the therapy, vascular sonography showed that the great saphenous vein was obstructed, and no serious complications occurred. Conclusion: For the treatment of lower extremity varices, fluoroscopically-guided foam sclerotherapy with injection of domestic sodium morrhuate is safe and effective with satisfactory results. This technique is a newly-developed micro-invasive therapy for lower extremity varices. (authors)

  6. Mesorad dose assessment model. Volume 1. Technical basis

    International Nuclear Information System (INIS)

    Scherpelz, R.I.; Bander, T.J.; Athey, G.F.; Ramsdell, J.V.

    1986-03-01

    MESORAD is a dose assessment model for emergency response applications. Using release data for as many as 50 radionuclides, the model calculates: (1) external doses resulting from exposure to radiation emitted by radionuclides contained in elevated or deposited material; (2) internal dose commitment resulting from inhalation; and (3) total whole-body doses. External doses from airborne material are calculated using semi-infinite and finite cloud approximations. At each stage in model execution, the appropriate approximation is selected after considering the cloud dimensions. Atmospheric processes are represented in MESORAD by a combination of Lagrangian puff and Gaussian plume dispersion models, a source depletion (deposition velocity) dry deposition model, and a wet deposition model using washout coefficients based on precipitation rates

  7. Assessment of exposure dose to workers in virtual decommissioning environments

    International Nuclear Information System (INIS)

    Jeong, KwanSeong; Moon, JeiKwon; Choi, ByungSeon; Hyun, Dongjun; Lee, Jonghwan; Kim, Ikjune; Kim, GeunHo; Seo, JaeSeok

    2014-01-01

    This paper is intended to suggest the method analyze and assess the exposure dose to workers in virtual decommissioning environments. To simulate a lot of decommissioning scenarios, decommissioning environments were designed in virtual reality. To simulate and assess the exposure dose to workers, human model also was designed in virtual environments. These virtual decommissioning environments made it possible to real-time simulate and assess the exposure dose to workers. This work was to be able to simulate scenarios of decommissioning so that exposure dose to workers could be measured and assessed. To establish the plan of exposure dose to workers during decommissioning of nuclear facilities before decommissioning activities are accomplished, the method of simulation assessment was developed in virtual radiological environments. But this work was developed as a tool of simulation for single subject mode. Afterwards, the simulation environment for multi-subjects mode will be upgraded by simultaneous modules with networking environments. Then the much more practical method will be developed by changing number of workers and duration of time under any circumstances of decommissioning

  8. Assessment of exposure dose to workers in virtual decommissioning environments

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, KwanSeong; Moon, JeiKwon; Choi, ByungSeon; Hyun, Dongjun; Lee, Jonghwan; Kim, Ikjune; Kim, GeunHo; Seo, JaeSeok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    This paper is intended to suggest the method analyze and assess the exposure dose to workers in virtual decommissioning environments. To simulate a lot of decommissioning scenarios, decommissioning environments were designed in virtual reality. To simulate and assess the exposure dose to workers, human model also was designed in virtual environments. These virtual decommissioning environments made it possible to real-time simulate and assess the exposure dose to workers. This work was to be able to simulate scenarios of decommissioning so that exposure dose to workers could be measured and assessed. To establish the plan of exposure dose to workers during decommissioning of nuclear facilities before decommissioning activities are accomplished, the method of simulation assessment was developed in virtual radiological environments. But this work was developed as a tool of simulation for single subject mode. Afterwards, the simulation environment for multi-subjects mode will be upgraded by simultaneous modules with networking environments. Then the much more practical method will be developed by changing number of workers and duration of time under any circumstances of decommissioning.

  9. The assessment of personal dose due to external radiation

    International Nuclear Information System (INIS)

    Boas, J.F.; Young, J.G.

    1990-01-01

    The fundamental basis of thermoluminescent dosimetry (TLD) is discussed and a number of considerations in the measurement of thermoluminescence described, with particular reference to CaSO 4 :Dy. The steps taken to convert a thermoluminescence measurement to an exposure and then an absorbed dose are outlined. The calculation of effective dose equivalents due to external exposure to γ-radiation in a number of situations commonly encountered in a uranium mine is discussed. Factors which may affect the accuracy of external dose assessments are described

  10. External dose assessment in the Ukraine following the Chernobyl accident

    Science.gov (United States)

    Frazier, Remi Jordan Lesartre

    While the physiological effects of radiation exposure have been well characterized in general, it remains unclear what the relationship is between large-scale radiological events and psychosocial behavior outcomes in individuals or populations. To investigate this, the National Science Foundation funded a research project in 2008 at the University of Colorado in collaboration with Colorado State University to expand the knowledge of complex interactions between radiation exposure, perception of risk, and psychosocial behavior outcomes by modeling outcomes for a representative sample of the population of the Ukraine which had been exposed to radiocontaminant materials released by the reactor accident at Chernobyl on 26 April 1986. In service of this project, a methodology (based substantially on previously published models specific to the Chernobyl disaster and the Ukrainian population) was developed for daily cumulative effective external dose and dose rate assessment for individuals in the Ukraine for as a result of the Chernobyl disaster. A software platform was designed and produced to estimate effective external dose and dose rate for individuals based on their age, occupation, and location of residence on each day between 26 April 1986 and 31 December 2009. A methodology was developed to transform published 137Cs soil deposition contour maps from the Comprehensive Atlas of Caesium Deposition on Europe after the Chernobyl Accident into a geospatial database to access these data as a radiological source term. Cumulative effective external dose and dose rate were computed for each individual in a 703-member cohort of Ukrainians randomly selected to be representative of the population of the country as a whole. Error was estimated for the resulting individual dose and dose rate values with Monte Carlo simulations. Distributions of input parameters for the dose assessment methodology were compared to computed dose and dose rate estimates to determine which

  11. Rectal dose assessment in patients submitted to high-dose-rate brachytherapy for uterine cervix cancer

    International Nuclear Information System (INIS)

    Oliveira, Jetro Pereira de; Batista, Delano Valdivino Santos; Bardella, Lucia Helena; Carvalho, Arnaldo Rangel

    2009-01-01

    Objective: The present study was aimed at developing a thermoluminescent dosimetric system capable of assessing the doses delivered to the rectum of patients submitted to high-dose-rate brachytherapy for uterine cervix cancer. Materials and methods: LiF:Mg,Ti,Na powder was the thermoluminescent material utilized for evaluating the rectal dose. The powder was divided into small portions (34 mg) which were accommodated in a capillary tube. This tube was placed into a rectal probe that was introduced into the patient's rectum. Results: The doses delivered to the rectum of six patients submitted to high-dose-rate brachytherapy for uterine cervix cancer evaluated by means of thermoluminescent dosimeters presented a good agreement with the planned values based on two orthogonal (anteroposterior and lateral) radiographic images of the patients. Conclusion: The thermoluminescent dosimetric system developed in the present study is simple and easy to be utilized as compared to other rectal dosimetry methods. The system has shown to be effective in the evaluation of rectal doses in patients submitted to high-dose-rate brachytherapy for uterine cervix cancer. (author)

  12. Peak Dose Assessment for Proposed DOE-PPPO Authorized Limits

    International Nuclear Information System (INIS)

    Maldonado, Delis

    2012-01-01

    The Oak Ridge Institute for Science and Education (ORISE), a U.S. Department of Energy (DOE) prime contractor, was contracted by the DOE Portsmouth/Paducah Project Office (DOE-PPPO) to conduct a peak dose assessment in support of the Authorized Limits Request for Solid Waste Disposal at Landfill C-746-U at the Paducah Gaseous Diffusion Plant (DOE-PPPO 2011a). The peak doses were calculated based on the DOE-PPPO Proposed Single Radionuclides Soil Guidelines and the DOE-PPPO Proposed Authorized Limits (AL) Volumetric Concentrations available in DOE-PPPO 2011a. This work is provided as an appendix to the Dose Modeling Evaluations and Technical Support Document for the Authorized Limits Request for the C-746-U Landfill at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky (ORISE 2012). The receptors evaluated in ORISE 2012 were selected by the DOE-PPPO for the additional peak dose evaluations. These receptors included a Landfill Worker, Trespasser, Resident Farmer (onsite), Resident Gardener, Recreational User, Outdoor Worker and an Offsite Resident Farmer. The RESRAD (Version 6.5) and RESRAD-OFFSITE (Version 2.5) computer codes were used for the peak dose assessments. Deterministic peak dose assessments were performed for all the receptors and a probabilistic dose assessment was performed only for the Offsite Resident Farmer at the request of the DOE-PPPO. In a deterministic analysis, a single input value results in a single output value. In other words, a deterministic analysis uses single parameter values for every variable in the code. By contrast, a probabilistic approach assigns parameter ranges to certain variables, and the code randomly selects the values for each variable from the parameter range each time it calculates the dose (NRC 2006). The receptor scenarios, computer codes and parameter input files were previously used in ORISE 2012. A few modifications were made to the parameter input files as appropriate for this effort. Some of these changes

  13. Development of a real-time radiological dose assessment system

    Energy Technology Data Exchange (ETDEWEB)

    Han, Moon Hee; Lee, Young Bok; Kim, Eun Han; Suh, Kyung Suk; Hwang, Won Tae; Choi, Young Gil

    1997-07-01

    A radiological dose assessment system named FADAS has been developed. This system is necessary to estimated the radiological consequences against a nuclear accident. Mass-consistent wind field module was adopted for the generation of wind field over the whole domain using the several measured wind data. Random-walk dispersion module is used for the calculation of the distribution of radionuclides in the atmosphere. And volume-equivalent numerical integration method has been developed for the assessment of external gamma exposure given from a randomly distributed radioactive materials and a dose data library has been made for rapid calculation. Field tracer experiments have been carried out for the purpose of analyzing the site-specific meteorological characteristics and increasing the accuracy of wind field generation and atmospheric dispersion module of FADAS. At first, field tracer experiment was carried out over flat terrain covered with rice fields using the gas samplers which were designed and manufactured by the staffs of KAERI. The sampled gas was analyzed using gas chromatograph. SODAR and airsonde were used to measure the upper wind. Korean emergency preparedness system CARE was integrated at Kori 4 nuclear power plants in 1995. One of the main functions of CARE is to estimate the radiological dose. The developed real-time dose assessment system FADAS was adopted in CARE as a tool for the radiological dose assessment. (author). 79 refs., 52 tabs., 94 figs.

  14. Skin dose assessment in routine personnel beta/gamma dosimetry

    International Nuclear Information System (INIS)

    Christensen, P.

    1980-01-01

    The International Commission on Radiological Protection (Publication 26) has recommended a tissue depth of 5 to 10 mg.cm -2 for skin dose assessments. This requirement is generally not fulfilled by routine monitoring procedures because of practical difficulties in using very thin dosemeters with low sensitivity and therefore a high minimum detectable dose. Especially for low-energy beta-ray exposures underestimations of the skin dose by a factor of more than ten may occur. Low-transparent graphite-mixed sintered LiF and Li 2 B 4 0 7 : Mn dosemeters were produced which show a skin-equivalent response to beta and gamma exposures over a wide range of energies. These have found wide-spread application for extremity dosimetry but have not yet been generally introduced in routine personnel beta/gamma monitoring. The following adaptations of existing routine monitoring systems for improved skin dose assessments have been investigated: 1) Placement of a supplementary, thin, skin-dose equivalent dosemeter in the TLD badge to give additional information on low-energy exposures. 2) Introduction of a second photomultiplier in the read-out chamber which enables a simultaneous determination of emitted TL from both sides of the dosemeter separately. This method makes use of the selfshielding of the dosemeter to give information on the low-energy dose contribution. 3) By diffusion of Li 2 B 4 0 7 into solid LiF-dosemeters it was possible to produce a surface layer with a new distinct glow-peak at about 340 deg C which is not present in the undiffused part of the LiF chip, and which can be utilized for the assessment of the skin-dose. Data on energy response and accuracy of dose measurement for beta/gamma exposures are given for the three methods and advantages and disadvantages are discussed (H.K.)

  15. Public Dose Assessment Modeling from Skyshine by Proton Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Mwambinga, S. A. [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Yoo, S. J. [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2013-10-15

    In this paper, the skyshine dose by proton accelerator (230 MeV) has been evaluated. The amount of dose by skyshine is related to some influence factors which are emission angle (Height wall), the thickness of ceiling and distance from source to receptor (Human body). Empirical formula is made by using MCNPX code results. It can easily calculate and assess dose from skyshine by proton accelerator. The skyshine doses are calculated with MCNPX code and DCFs in ICRP 116. Thereafter, we made empirical formula which can calculate dose easily and be compared with the results of MCNPX. The maximum exposure point by skyshine is about 5 ∼ 10 m from source. Therefore, the licensee who wants to operate the proton accelerator must keep the appropriate distance from accelerator and set the fence to restrict the approach by the public. And, exposure doses by accelerator depend on operating time and proton beam intensities. Eq. (6) suggested in this study is just considered for mono energy proton accelerator. Therefore, it is necessary to expand the dose calculation to diverse proton energies. Radiations like neutron and photon generated by high energy proton accelerators over 10 MeV, are important exposure sources to be monitored to radiation workers and the public members near the facility. At that case, one of the exposure pathways to the public who are located in near the facility is skyshine. Neutrons and photons can be scattered by the atmosphere near the facility and exposed to public as scattered dose. All of the facilities using high energy radiation and NDI (Non-Destructive Inspection) which is tested at open field, skyshine dose must be taken into consideration. Skyshine dose is not related to the wall thickness of radiation shielding directly.

  16. Radiological dose assessment from the operation of Daeduk nuclear facilities

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Won Tae; Kim, Eun Han; Suh, Kyung Suk; Choi, Young Gil [Korea Atomic Energy Research Institute, Taejon (Korea)

    2000-02-01

    The objective of this project is to assure the public acceptance for nuclear facilities, and the environmental safety from the operation of Daeduk nuclear facilities, such as HANARO research reactor, nuclear fuel processing facilities and others. For identifying the integrity of their facilities, the maximum individual doses at the site boundary and on the areas with high population density were assessed. Also, the collective doses within radius 80 km from the site were assessed. The radiation impacts for residents around the site from the operation of Daeduk nuclear facilities in 1999 were neglectable. 8 refs., 10 figs., 27 tabs. (Author)

  17. Assessment of dose received by organ in lumbosacral examination

    International Nuclear Information System (INIS)

    Eltyeib, Nashwa Kheirallah

    2014-11-01

    The biological damage produced by radiation is closely related to the amount of energy absorbed in the case x- rays. Measurement of produced ionizing provides a useful assessment of the total energy absorbed. This study was performed in Khartoum Teaching Hospital in period of January to June 2014. This study was performed to assess the effective dose (ED) received in lumbosacral radiography examination and to analyze effective dose distributions among radiological department under study. The study was performed in Khartoum Teaching Hospital, covering two x-ray units and a sample of 50 patients. The following parameters were recorded: age weight, height, body mass index (BMI) derived from mass (kg) and (height. (m)) and exposure factors. The dose was measured for lumbosacral x- rays examination. For effective dose calculation, the entrance surface dose (ESD) values were estimated from the x-ray tube output parameters for lumbosacral spine A P and lateral examinations. The ED values were then calculated from the obtained ESD values using IAEA calculation methods. Effective doses were than calculated from energy imported using ED conversion factors by IAEA. The results of ED values calculated showed that patient exposures were within the normal range of exposure. The mean ED values calculated were (2.49 ±0.03) mGy and (5.5.60 ± 0.0.22) mGy for Lumbosacral spine A P and lateral examinations, respectively. Further studies are recommended with more number of patients and using more modalities for comparison.(Author)

  18. Fluoroscopic extraction of esophageal foreign body

    International Nuclear Information System (INIS)

    Chon, Su Bin; Han, Young Min; Chung, Gyung Ho; Sohn, Myung Hee; Kim, Chong Soo; Choi, Ki Chul; Song, Young Ho; Choi, Yeon Wha

    1993-01-01

    The purpose of this study is to report our 5 year experience with fluoroscopic removal of blunt esophageal foreign body or impacted food in 15 consecutive patients who were referred by endoscopists because they couln't remove it endoscopically. The foreign body or impacted food was a piece of meat, a bean, a badug stone or a beef bone. Thirteen patients had underlying disease (11 of corrosive stricture, 2 of postopertive stricture) but 2 patient did not. We removed the object using one of the following 4 techniques: Basket extraction technique. Foley catheter technique, single balloon technique (dilatation of stenosis for passing the food into the stomach and for the treatment of the stricture as well), double balloon technique (removal of the foregin body by trapping it with two valvuloplasty balloons). Removal was successful in all patients. Esophageal performation occurred in one patient using the sibgle balloon technique, who treated nonoperatively by means of fasting, antibiotics and parenteral alimentation. No procedure related death occurred in these series. In conclusion, fliuroscopic removal of blunt esophageal foreign bodies of impacted food with various techniques is promising alternative to esophagoscopic removal

  19. Assessment of organ equivalent doses and effective doses from diagnostic X-ray examinations

    International Nuclear Information System (INIS)

    Park, Sang Hyun

    2003-02-01

    The MIRD-type adult male, female and age 10 phantoms were constructed to evaluate organ equivalent dose and effective dose of patient due to typical diagnostic X-ray examination. These phantoms were constructed with external and internal dimensions of Korean. The X-ray energy spectra were generated with SPEC78. MCNP4B ,the general-purposed Monte Carlo code, was used. Information of chest PA , chest LAT, and abdomen AP diagnostic X-ray procedures was collected on the protocol of domestic hospitals. The results showed that patients pick up approximate 0.02 to 0.18 mSv of effective dose from a single chest PA examination, and 0.01 to 0.19 mSv from a chest LAT examination depending on the ages. From an abdomen AP examination, patients pick up 0.17 to 1.40 mSv of effective dose. Exposure time, organ depth from the entrance surface and X-ray beam field coverage considerably affect the resulting doses. Deviation among medical institutions is somewhat high, and this indicated that medical institutions should interchange their information and the need of education for medical staff. The methodology and the established system can be applied, with some expansion, to dose assessment for other medical procedures accompanying radiation exposure of patients like nuclear medicine or therapeutic radiology

  20. Assessments for high dose radionuclide therapy treatment planning

    International Nuclear Information System (INIS)

    Fisher, D.R.

    2003-01-01

    Advances in the biotechnology of cell specific targeting of cancer and the increased number of clinical trials involving treatment of cancer patients with radiolabelled antibodies, peptides, and similar delivery vehicles have led to an increase in the number of high dose radionuclide therapy procedures. Optimised radionuclide therapy for cancer treatment is based on the concept of absorbed dose to the dose limiting normal organ or tissue. The limiting normal tissue is often the red marrow, but it may sometimes be the lungs, liver, intestinal tract, or kidneys. Appropriate treatment planning requires assessment of radiation dose to several internal organs and tissues, and usually involves biodistribution studies in the patient using a tracer amount of radionuclide bound to the targeting agent and imaged at sequential timepoints using a planar gamma camera. Time-activity curves are developed from the imaging data for the major organ tissues of concern, for the whole body and sometimes for selected tumours. Patient specific factors often require that dose estimates be customised for each patient. In the United States, the Food and Drug Administration regulates the experimental use of investigational new drugs and requires 'reasonable calculation of radiation absorbed dose to the whole body and to critical organs' using the methods prescribed by the Medical Internal Radiation Dose (MIRD) Committee of the Society of Nuclear Medicine. Review of high dose studies shows that some are conducted with minimal dosimetry, that the marrow dose is difficult to establish and is subject to large uncertainties. Despite the general availability of software, internal dosimetry methods often seem to be inconsistent from one clinical centre to another. (author)

  1. The assessment of the carcinogenic effects of low dose radiation

    International Nuclear Information System (INIS)

    Tubiana, M.; Lafuma, J.; Masse, R.; Latarjet, R.

    1991-01-01

    It is concluded that the exclusion of patients for the purposes of risk estimation, the choice of a particular relative risk projection model and of a dose reduction factor equal to 2 are all decisions which result in an overestimation of the actual risk. These choices can be understood when the aim is radiation protection and when it is safer to overestimate the risk; however, they are open to criticism if the aim is a realistic assessment of the risk. For low doses, below 50 mSv/year, and when all causes of uncertainty are added, the actual risk might be markedly lower than the risk estimated with the ICRP (1991) carcinogenic risk coefficient and the DRF estimated by ICRP. Future studies should aim at providing direct and more precise assessments of risk coefficients in the low dose region. (Author)

  2. Integrated Worker Radiation Dose Assessment for the K Basins

    International Nuclear Information System (INIS)

    NELSON, J.V.

    1999-01-01

    This report documents an assessment of the radiation dose workers at the K Basins are expected to receive in the process of removing spent nuclear fuel from the storage basins. The K Basins (K East and K West) are located in the Hanford 100K Area

  3. Excipient Usage Technical Risk Assessment for Generic Solid Dose Products

    Directory of Open Access Journals (Sweden)

    Ajay Babu Pazhayattil

    2017-09-01

    Full Text Available This paper proposes an assessment methodology for solid dose generic small molecule drug products. It addresses the ‘usage of the excipient’ portion of the trinomial by utilizing the systematic approach of Risk Identification, Risk Analysis and Risk Evaluation as per ICH Q9 Quality Risk Management outlined for developing risk control strategies. The assessment and maintenance of excipient risk profile is essential to minimize any potential risk associated to excipients impacting patients.

  4. Reduction of radiation exposure while maintaining high-quality fluoroscopic images during interventional cardiology using novel x-ray tube technology with extra beam filtering.

    Science.gov (United States)

    den Boer, A; de Feyter, P J; Hummel, W A; Keane, D; Roelandt, J R

    1994-06-01

    Radiographic technology plays an integral role in interventional cardiology. The number of interventions continues to increase, and the associated radiation exposure to patients and personnel is of major concern. This study was undertaken to determine whether a newly developed x-ray tube deploying grid-switched pulsed fluoroscopy and extra beam filtering can achieve a reduction in radiation exposure while maintaining fluoroscopic images of high quality. Three fluoroscopic techniques were compared: continuous fluoroscopy, pulsed fluoroscopy, and a newly developed high-output pulsed fluoroscopy with extra filtering. To ascertain differences in the quality of images and to determine differences in patient entrance and investigator radiation exposure, the radiated volume curve was measured to determine the required high voltage levels (kVpeak) for different object sizes for each fluoroscopic mode. The fluoroscopic data of 124 patient procedures were combined. The data were analyzed for radiographic projections, image intensifier field size, and x-ray tube kilovoltage levels (kVpeak). On the basis of this analysis, a reference procedure was constructed. The reference procedure was tested on a phantom or dummy patient by all three fluoroscopic modes. The phantom was so designed that the kilovoltage requirements for each projection were comparable to those needed for the average patient. Radiation exposure of the operator and patient was measured during each mode. The patient entrance dose was measured in air, and the operator dose was measured by 18 dosimeters on a dummy operator. Pulsed compared with continuous fluoroscopy could be performed with improved image quality at lower kilovoltages. The patient entrance dose was reduced by 21% and the operator dose by 54%. High-output pulsed fluoroscopy with extra beam filtering compared with continuous fluoroscopy improved the image quality, lowered the kilovoltage requirements, and reduced the patient entrance dose by 55% and

  5. Technical Note: SCUDA: A software platform for cumulative dose assessment

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seyoun; McNutt, Todd; Quon, Harry; Wong, John; Lee, Junghoon, E-mail: rshekhar@childrensnational.org, E-mail: junghoon@jhu.edu [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, Maryland 21231 (United States); Plishker, William [IGI Technologies, Inc., College Park, Maryland 20742 (United States); Shekhar, Raj, E-mail: rshekhar@childrensnational.org, E-mail: junghoon@jhu.edu [IGI Technologies, Inc., College Park, Maryland 20742 and Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Health System, Washington, DC 20010 (United States)

    2016-10-15

    Purpose: Accurate tracking of anatomical changes and computation of actually delivered dose to the patient are critical for successful adaptive radiation therapy (ART). Additionally, efficient data management and fast processing are practically important for the adoption in clinic as ART involves a large amount of image and treatment data. The purpose of this study was to develop an accurate and efficient Software platform for CUmulative Dose Assessment (SCUDA) that can be seamlessly integrated into the clinical workflow. Methods: SCUDA consists of deformable image registration (DIR), segmentation, dose computation modules, and a graphical user interface. It is connected to our image PACS and radiotherapy informatics databases from which it automatically queries/retrieves patient images, radiotherapy plan, beam data, and daily treatment information, thus providing an efficient and unified workflow. For accurate registration of the planning CT and daily CBCTs, the authors iteratively correct CBCT intensities by matching local intensity histograms during the DIR process. Contours of the target tumor and critical structures are then propagated from the planning CT to daily CBCTs using the computed deformations. The actual delivered daily dose is computed using the registered CT and patient setup information by a superposition/convolution algorithm, and accumulated using the computed deformation fields. Both DIR and dose computation modules are accelerated by a graphics processing unit. Results: The cumulative dose computation process has been validated on 30 head and neck (HN) cancer cases, showing 3.5 ± 5.0 Gy (mean±STD) absolute mean dose differences between the planned and the actually delivered doses in the parotid glands. On average, DIR, dose computation, and segmentation take 20 s/fraction and 17 min for a 35-fraction treatment including additional computation for dose accumulation. Conclusions: The authors developed a unified software platform that provides

  6. Radiological assessment. A textbook on environmental dose analysis

    International Nuclear Information System (INIS)

    Till, J.E.; Meyer, H.R.

    1983-09-01

    Radiological assessment is the quantitative process of estimating the consequences to humans resulting from the release of radionuclides to the biosphere. It is a multidisciplinary subject requiring the expertise of a number of individuals in order to predict source terms, describe environmental transport, calculate internal and external dose, and extrapolate dose to health effects. Up to this time there has been available no comprehensive book describing, on a uniform and comprehensive level, the techniques and models used in radiological assessment. Radiological Assessment is based on material presented at the 1980 Health Physics Society Summer School held in Seattle, Washington. The material has been expanded and edited to make it comprehensive in scope and useful as a text. Topics covered include (1) source terms for nuclear facilities and Medical and Industrial sites; (2) transport of radionuclides in the atmosphere; (3) transport of radionuclides in surface waters; (4) transport of radionuclides in groundwater; (5) terrestrial and aquatic food chain pathways; (6) reference man; a system for internal dose calculations; (7) internal dosimetry; (8) external dosimetry; (9) models for special-case radionuclides; (10) calculation of health effects in irradiated populations; (11) evaluation of uncertainties in environmental radiological assessment models; (12) regulatory standards for environmental releases of radionuclides; (13) development of computer codes for radiological assessment; and (14) assessment of accidental releases of radionuclides

  7. Radiological assessment. A textbook on environmental dose analysis

    Energy Technology Data Exchange (ETDEWEB)

    Till, J.E.; Meyer, H.R. (eds.)

    1983-09-01

    Radiological assessment is the quantitative process of estimating the consequences to humans resulting from the release of radionuclides to the biosphere. It is a multidisciplinary subject requiring the expertise of a number of individuals in order to predict source terms, describe environmental transport, calculate internal and external dose, and extrapolate dose to health effects. Up to this time there has been available no comprehensive book describing, on a uniform and comprehensive level, the techniques and models used in radiological assessment. Radiological Assessment is based on material presented at the 1980 Health Physics Society Summer School held in Seattle, Washington. The material has been expanded and edited to make it comprehensive in scope and useful as a text. Topics covered include (1) source terms for nuclear facilities and Medical and Industrial sites; (2) transport of radionuclides in the atmosphere; (3) transport of radionuclides in surface waters; (4) transport of radionuclides in groundwater; (5) terrestrial and aquatic food chain pathways; (6) reference man; a system for internal dose calculations; (7) internal dosimetry; (8) external dosimetry; (9) models for special-case radionuclides; (10) calculation of health effects in irradiated populations; (11) evaluation of uncertainties in environmental radiological assessment models; (12) regulatory standards for environmental releases of radionuclides; (13) development of computer codes for radiological assessment; and (14) assessment of accidental releases of radionuclides.

  8. Biosphere model for assessing doses from nuclear waste disposal

    International Nuclear Information System (INIS)

    Zach, R.; Amiro, B.D.; Davis, P.A.; Sheppard, S.C.; Szekeley, J.G.

    1994-01-01

    The biosphere model, BIOTRAC, for predicting long term nuclide concentrations and radiological doses from Canada's nuclear fuel waste disposal concept of a vault deep in plutonic rock of the Canadian Shield is presented. This generic, boreal zone biosphere model is based on scenario analysis and systems variability analysis using Monte Carlo simulation techniques. Conservatism is used to bridge uncertainties, even though this creates a small amount of extra nuclide mass. Environmental change over the very long assessment period is mainly handled through distributed parameter values. The dose receptors are a critical group of humans and four generic non-human target organisms. BIOTRAC includes six integrated submodels and it interfaces smoothly with a geosphere model. This interface includes a bedrock well. The geosphere model defines the discharge zones of deep groundwater where nuclides released from the vault enter the biosphere occupied by the dose receptors. The size of one of these zones is reduced when water is withdrawn from the bedrock well. Sensitivity analysis indicates 129 I is by far the most important radionuclide. Results also show bedrock-well water leads to higher doses to man than lake water, but the former doses decrease with the size of the critical group. Under comparable circumstances, doses to the non-human biota are greater than those for man

  9. Dose Assessment Model for Chronic Atmospheric Releases of Tritium

    International Nuclear Information System (INIS)

    Shen Huifang; Yao Rentai

    2010-01-01

    An improved dose assessment model for chronic atmospheric releases of tritium was proposed. The proposed model explicitly considered two chemical forms of tritium.It was based on conservative assumption of transfer of tritiated water (HTO) from air to concentration of HTO and organic beam tritium (OBT) in vegetable and animal products.The concentration of tritium in plant products was calculated based on considering dividedly leafy plant and not leafy plant, meanwhile the concentration contribution of tritium in the different plants from the tritium in soil was taken into account.Calculating the concentration of HTO in animal products, average water fraction of animal products and the average weighted tritium concentration of ingested water based on the fraction of water supplied by each source were considered,including skin absorption, inhalation, drinking water and food.Calculating the annual doses, the ingestion doses were considered, at the same time the contribution of inhalation and skin absorption to the dose was considered. Concentrations in foodstuffs and dose of annual adult calculated with the specific activity model, NEWTRI model and the model proposed by the paper were compared. The results indicate that the model proposed by the paper can predict accurately tritium doses through the food chain from chronic atmospheric releases. (authors)

  10. A model for radiological dose assessment in an urban environment

    International Nuclear Information System (INIS)

    Hwang, Won Tae; Kim, Eun Han; Jeong, Hyo Joon; Suh, Kyung Suk; Han, Moon Hee

    2007-01-01

    A model for radiological dose assessment in an urban environment, METRO-K has been developed. Characteristics of the model are as follows ; 1) mathematical structures are simple (i.e. simplified input parameters) and easy to understand due to get the results by analytical methods using experimental and empirical data, 2) complex urban environment can easily be made up using only 5 types of basic surfaces, 3) various remediation measures can be applied to different surfaces by evaluating the exposure doses contributing from each contamination surface. Exposure doses contributing from each contamination surface at a particular location of a receptor were evaluated using the data library of kerma values as a function of gamma energy and contamination surface. A kerma data library was prepared for 7 representative types of Korean urban building by extending those data given for 4 representative types of European urban buildings. Initial input data are daily radionuclide concentration in air and precipitation, and fraction of chemical type. Final outputs are absorbed dose rate in air contributing from the basic surfaces as a function of time following a radionuclide deposition, and exposure dose rate contributing from various surfaces constituting the urban environment at a particular location of a receptor. As the result of a contaminative scenario for an apartment built-up area, exposure dose rates show a distinct difference for surrounding environment as well as locations of a receptor

  11. Thoron in the air: assessment of the occupational dose

    International Nuclear Information System (INIS)

    Campos, Marcia Pires de

    1999-01-01

    The occupational dose due to inhalation of thoron was assessed through the committed effective dose and the committed equivalent dose received by workers exposed to the radionuclide at the nuclear materials storage site and the thorium purification plant of the Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP). The radiation doses were performed by compartmental analysis following the compartmental model of the lung and biokinetic model of the lead, through the thoron equilibrium equivalent concentrations. These values were obtained by gamma ray spectrometry, total alpha count and alpha particle spectrometry of air samples glass fiber filters. The results of the thoron equilibrium equivalent concentration varied from 0.3 to 0,67 Bq/m 3 at the nuclear materials storage site and from 0.9 to 249.8 Bq/m 3 at the thorium purification plant. The committed effective dose due to thoron inhalation varied from 0.03 mSv/a to 0.67 mSv/a at the nuclear materials storage site and from 0.12 mSv/a to 6.0 mSv/a at the thorium purification plant. The risk assessment of lung cancer and fatal cancers for the workers exposed to thoron at the nuclear materials storage site and the thorium purification plant showed an increment for both risk cancer. (author)

  12. Construction of average adult Japanese voxel phantoms for dose assessment

    International Nuclear Information System (INIS)

    Sato, Kaoru; Takahashi, Fumiaki; Satoh, Daiki; Endo, Akira

    2011-12-01

    The International Commission on Radiological Protection (ICRP) adopted the adult reference voxel phantoms based on the physiological and anatomical reference data of Caucasian on October, 2007. The organs and tissues of these phantoms were segmented on the basis of ICRP Publication 103. In future, the dose coefficients for internal dose and dose conversion coefficients for external dose calculated using the adult reference voxel phantoms will be widely used for the radiation protection fields. On the other hand, the body sizes and organ masses of adult Japanese are generally smaller than those of adult Caucasian. In addition, there are some cases that the anatomical characteristics such as body sizes, organ masses and postures of subjects influence the organ doses in dose assessment for medical treatments and radiation accident. Therefore, it was needed to use human phantoms with average anatomical characteristics of Japanese. The authors constructed the averaged adult Japanese male and female voxel phantoms by modifying the previously developed high-resolution adult male (JM) and female (JF) voxel phantoms. It has been modified in the following three aspects: (1) The heights and weights were agreed with the Japanese averages; (2) The masses of organs and tissues were adjusted to the Japanese averages within 10%; (3) The organs and tissues, which were newly added for evaluation of the effective dose in ICRP Publication 103, were modeled. In this study, the organ masses, distances between organs, specific absorbed fractions (SAFs) and dose conversion coefficients of these phantoms were compared with those evaluated using the ICRP adult reference voxel phantoms. This report provides valuable information on the anatomical and dosimetric characteristics of the averaged adult Japanese male and female voxel phantoms developed as reference phantoms of adult Japanese. (author)

  13. TSD-DOSE: A radiological dose assessment model for treatment, storage, and disposal facilities

    International Nuclear Information System (INIS)

    Pfingston, M.; Arnish, J.; LePoire, D.; Chen, S.-Y.

    1998-01-01

    Past practices at US Department of Energy (DOE) field facilities resulted in the presence of trace amounts of radioactive materials in some hazardous chemical wastes shipped from these facilities. In May 1991, the DOE Office of Waste Operations issued a nationwide moratorium on shipping all hazardous waste until procedures could be established to ensure that only nonradioactive hazardous waste would be shipped from DOE facilities to commercial treatment, storage, and disposal (TSD) facilities. To aid in assessing the potential impacts of shipments of mixed radioactive and chemically hazardous wastes, a radiological assessment computer model (or code) was developed on the basis of detailed assessments of potential radiological exposures and doses for eight commercial hazardous waste TSD facilities. The model, called TSD-DOSE, is designed to incorporate waste-specific and site-specific data to estimate potential radiological doses to on-site workers and the off-site public from waste-handling operations at a TSD facility. The code is intended to provide both DOE and commercial TSD facilities with a rapid and cost-effective method for assessing potential human radiation exposures from the processing of chemical wastes contaminated with trace amounts of radionuclides

  14. The relative importance of ingestion for multiple pathway dose assessments

    International Nuclear Information System (INIS)

    Wicker, W.; Grogan, H.; Bergstroem, U.; Hoffman, O.

    1991-01-01

    The general purpose of this report is to examine the relative importance of ingestion pathways, and particularly food chain transport in overall dose assessment. The importance of ingestion pathways is examined for various release scenarios and radionuclides because the findings are expected to differ with circumstances. The degree to which contaminated food products contribute to the total dose will affect the importance of accuracy and uncertainty of food chain model predictions, which is the main thrust of the Biospheric Model Validation Study (BIOMOVS). This analysis requires that all modes of radiation exposure be examined, including inhalation, external exposure, and the various ingestion pathways. (2 figs., 2 tabs.)

  15. Radiation dose reduction in paediatric coronary computed tomography: assessment of effective dose and image quality

    International Nuclear Information System (INIS)

    Habib Geryes, Bouchra; Calmon, Raphael; Boddaert, Nathalie; Khraiche, Diala; Bonnet, Damien; Raimondi, Francesca

    2016-01-01

    To assess the impact of different protocols on radiation dose and image quality for paediatric coronary computed tomography (cCT). From January-2012 to June-2014, 140 children who underwent cCT on a 64-slice scanner were included. Two consecutive changes in imaging protocols were performed: 1) the use of adaptive statistical iterative reconstruction (ASIR); 2) the optimization of acquisition parameters. Effective dose (ED) was calculated by conversion of the dose-length product. Image quality was assessed as excellent, good or with significant artefacts. Patients were divided in three age groups: 0-4, 5-7 and 8-18 years. The use of ASIR combined to the adjustment of scan settings allowed a reduction in the median ED of 58 %, 82 % and 85 % in 0-4, 5-7 and 8-18 years group, respectively (7.3 ± 1.4 vs 3.1 ± 0.7 mSv, 5.5 ± 1.6 vs 1 ± 1.9 mSv and 5.3 ± 5.0 vs 0.8 ± 2.0 mSv, all p < 0,05). Prospective protocol was used in 51 % of children. The reduction in radiation dose was not associated with reduction in diagnostic image quality as assessed by the frequency of coronary segments with excellent or good image quality (88 %). cCT can be obtained at very low radiation doses in children using ASIR, and prospective acquisition with optimized imaging parameters. (orig.)

  16. TSD-DOSE : a radiological dose assessment model for treatment, storage, and disposal facilities

    International Nuclear Information System (INIS)

    Pfingston, M.

    1998-01-01

    In May 1991, the U.S. Department of Energy (DOE), Office of Waste Operations, issued a nationwide moratorium on shipping slightly radioactive mixed waste from DOE facilities to commercial treatment, storage, and disposal (TSD) facilities. Studies were subsequently conducted to evaluate the radiological impacts associated with DOE's prior shipments through DOE's authorized release process under DOE Order 5400.5. To support this endeavor, a radiological assessment computer code--TSD-DOSE (Version 1.1)--was developed and issued by DOE in 1997. The code was developed on the basis of detailed radiological assessments performed for eight commercial hazardous waste TSD facilities. It was designed to utilize waste-specific and site-specific data to estimate potential radiological doses to on-site workers and the off-site public from waste handling operations at a TSD facility. The code has since been released for use by DOE field offices and was recently used by DOE to evaluate the release of septic waste containing residual radioactive material to a TSD facility licensed under the Resource Conservation and Recovery Act. Revisions to the code were initiated in 1997 to incorporate comments received from users and to increase TSD-DOSE's capability, accuracy, and flexibility. These updates included incorporation of the method used to estimate external radiation doses from DOE's RESRAD model and expansion of the source term to include 85 radionuclides. In addition, a detailed verification and benchmarking analysis was performed

  17. Assessment of medical staff radiation doses received in some interventional examination

    International Nuclear Information System (INIS)

    Oenal, E.

    2006-03-01

    The aim of this work is to suggest a simple method for the estimation of cardiologist extremity doses. The extremity and effective doses The extremity and effective doses of nine cardiologists working at five different angiographic units were measured for 157 interventional examinations. Simultaneous measurement of patient doses were also carried out using a DAP meter separately for each projection. Fluoroscopy time (T f l), number of radiographic frames (N) were recorded on-line during these measurements. A Rando phantom was exposed at similar projections with patient studies and one minute of fluoroscopic exposure (D 1 50 n T f l n ) and one frame of radiographic exposure (D 1 50 n N n ) were determined for each projection. Scatter radiations from these exposures were also measured at 50, 100 and 150 cm above the floor level at the cardiologist positions for the estimation of legs, wrists and thyroid (or eye) doses. Weighting of projections were determined for the patient group of each cardiologist using the recorded values of T f l and N r f. Extremity doses, D x were calculated with the following formula: D 1 50=Σ n D 1 50 n T f l n (T f l n )+Σ n D 1 50 n N n (N n ), n=4, 5, 6, 7, 10. n gives the projection numbert and x is the distance from the floor level. Measured and calculated extremity doses for each cardiologist were in good agreement. The calculated doses for 50cm and 100cm were found within the measured values of left and right legs and wrists. The use of dominant projection data alone still provided comparable results

  18. Post-closure radiation dose assessment for Yucca Mountain repository

    International Nuclear Information System (INIS)

    Jia Mingyan; Zhang Xiabin; Yang Chuncai

    2006-01-01

    A brief introduction of post-closure long-term radiation safety assessment results was represented for the yucca mountain high-level waste geographic disposal repository. In 1 million years after repository closure, for the higher temperature repository operating mode, the peak annual dose would be 150 millirem (120 millirem under the lower-temperature operating mode) to a reasonably maximally exposed individual approximately 18 kilometers (11 miles) from the repository. The analysis of a drilling intrusion event occurring at 30,000 years indicated a peak of the mean annual dose to the reasonably maximally exposed individual approximately 18 kilometers (11 miles) downstream of the repository would be 0.002 millirem. The analysis of an igneous activity scenario, including a volcanic eruption event and igneous intrusion event indicated a peak of the mean annual dose to the reasonably maximally exposed individual approximately 18 kilometers downstream of the repository would be 0.1 millirem. (authors)

  19. Assessment of cosmic radiation doses received by air crew

    International Nuclear Information System (INIS)

    McAulay, I.R.

    1998-01-01

    Cosmic radiation in the atmosphere is such a complex mixture of radiation type that it is difficult to get a single instrument which is suitable for such measurements. Passive devices such as film badges and track etch detectors have also been used, but again present difficulties of interpretation and requirements of multiple devices to accommodate the different types of radiation encountered. In summary, air crew are the occupational group most highly exposed to radiation. The radiation doses experienced by them are sufficiently high as to require assessment on a regular basis and possible control by appropriate rostering. There appears little possibility of the dose limit for workers being exceeded, except possibly in the case of pregnant female crew. This category of air crew should be the subject of special controls aimed at ensuring that the dose limits for the foetus should not be exceeded

  20. Improvement of the following accident dose assessment system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Enn Han; Han, Moon Hee; Suh, Kyung Suk; Hwang, Won Tae; Choi, Young Gil [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1999-12-15

    The FADAS has been updates for calculating the real-time wind fields continuously at the nuclear sites in Korea. The system has been constructed to compute the wind fields using its own process for the dummy meteorological data, and dose not effect on the overall wind field module. If the radioactive materials are released into the atmosphere in real situation, the calculations of wind fields and exposure dose in the previous FADAS are performed in the case of the recognition of the above situation in the source term evaluation module. The current version of FADAS includes the program for evaluating the effect of the predicted accident and the assumed scenario together. The dose assessment module is separated into the real-time and the supposed accident respectively.

  1. Fluoroscopic guidance for placing a double lumen endotracheal tube in adults.

    Science.gov (United States)

    Calenda, Emile; Baste, Jean Marc; Hajjej, Ridha; Rezig, Najiba; Moriceau, Jerome; Diallo, Yaya; Sghaeir, Slim; Danielou, Eric; Peillon, Christophe

    2014-09-01

    The aim of this study was to assess the right placement of the double lumen endotracheal tube with fluoroscopic guidance, which is used in first intention prior to the fiberscope in our institution. This was a prospective observational study. The study was conducted in vascular and thoracic operating rooms. We enrolled 205 patients scheduled for thoracic surgery, with ASA physical statuses of I (n = 37), II (n = 84), III (n = 80), and IV (n = 4). Thoracic procedures were biopsy (n = 20), wedge (n = 34), culminectomy (n = 6), lobectomy (n = 82), pneumonectomy (n = 4), sympathectomy (n = 9), symphysis (n = 47), and thymectomy (n = 3). The intubation with a double lumen tube was performed with the help of a laryngoscope. Tracheal and bronchial balloons were inflated and auscultation was performed after right and left exclusions. One shot was performed to locate the position of the bronchial tube and the hook. Fluoroscopic guidance was used to relocate the tube in case of a wrong position. When the fluoroscopic guidance failed to position the tube, a fiberscope was used. Perioperative collapse of the lung was assessed by the surgeon during the surgery. Correct fluoroscopic image was obtained after the first attempt in 58.5% of patients therefore a misplaced position was encountered in 41.5%. The fluoroscopic guidance allowed an exact repositioning in 99.5% of cases, and the mean duration of the procedure was 8 minutes. A fiberscope was required to move the hook for one patient. We did not notice a moving of the double lumen endotracheal tube during the surgery. The surgeon satisfaction was 100%. The fluoroscopy evidenced the right position of the double lumen tube and allowed a right repositioning in 99.5% of patients with a very simple implementation. Copyright © 2014. Published by Elsevier B.V.

  2. Development of radiation dose assessment system for radiation accident (RADARAC)

    International Nuclear Information System (INIS)

    Takahashi, Fumiaki; Shigemori, Yuji; Seki, Akiyuki

    2009-07-01

    The possibility of radiation accident is very rare, but cannot be regarded as zero. Medical treatments are quite essential for a heavily exposed person in an occurrence of a radiation accident. Radiation dose distribution in a human body is useful information to carry out effectively the medical treatments. A radiation transport calculation utilizing the Monte Carlo method has an advantageous in the analysis of radiation dose inside of the body, which cannot be measured. An input file, which describes models for the accident condition and quantities of interest, should be prepared to execute the radiation transport calculation. Since the accident situation, however, cannot be prospected, many complicated procedures are needed to make effectively the input file soon after the occurrence of the accident. In addition, the calculated doses are to be given in output files, which usually include much information concerning the radiation transport calculation. Thus, Radiation Dose Assessment system for Radiation Accident (RADARAC) was developed to derive effectively radiation dose by using the MCNPX or MCNP code. RADARAC mainly consists of two parts. One part is RADARAC - INPUT, which involves three programs. A user can interactively set up necessary resources to make input files for the codes, with graphical user interfaces in a personnel computer. The input file includes information concerning the geometric structure of the radiation source and the exposed person, emission of radiations during the accident, physical quantities of interest and so on. The other part is RADARAC - DOSE, which has one program. The results of radiation doses can be effectively indicated with numerical tables, graphs and color figures visibly depicting dose distribution by using this program. These results are obtained from the outputs of the radiation transport calculations. It is confirmed that the system can effectively make input files with a few thousand lines and indicate more than 20

  3. Dose assessment in patients undergoing lung examinations by computed tomography

    International Nuclear Information System (INIS)

    Gonzaga, Natalia B.; Silva, Teogenes A. da; Magalhaes, Marcos J.

    2011-01-01

    In the last fifteen years, the use of computed tomography (CT) has increased alongside other radiology technologies technologies. Its contribution has already achieved 34% in terms of doses undergone by patients. Radiation protection of patients submitted to CT examinations is based on the knowledge of internationally defined dosimetric quantities as the CT air kerma-length product (P K,L ) and weighted CT air kerma index (C w ). In Brazil, those dosimetric quantities are not routinely used and the optimization criteria are based only upon the MSAD - the average dose in multislices. In this work, the dosimetric quantities P K,L and C w were assessed by the CT Expo program for seven protocols used daily for lung examinations in adults with the use of Siemens and Philips scanners in Belo Horizonte. Results showed that P K,L values varied from 163 to 558 mGy.cm and the C w from 9.6 to 17.5 mGy. All results were found to be lower than the reference values internationally recommended by ICRP 87 and the European Community 16262 (30 mGy and 650 mGy.cm). The large dose ranges suggest that optimization of patient dose reduction is still possible without losses in the image quality and new reference dose levels could be recommended after a large survey to be carried out in the region. (author)

  4. Methods of assessing total doses integrated across pathways

    International Nuclear Information System (INIS)

    Grzechnik, M.; Camplin, W.; Clyne, F.; Allott, R.; Webbe-Wood, D.

    2006-01-01

    Calculated doses for comparison with limits resulting from discharges into the environment should be summed across all relevant pathways and food groups to ensure adequate protection. Current methodology for assessments used in the radioactivity in Food and the Environment (R.I.F.E.) reports separate doses from pathways related to liquid discharges of radioactivity to the environment from those due to gaseous releases. Surveys of local inhabitant food consumption and occupancy rates are conducted in the vicinity of nuclear sites. Information has been recorded in an integrated way, such that the data for each individual is recorded for all pathways of interest. These can include consumption of foods, such as fish, crustaceans, molluscs, fruit and vegetables, milk and meats. Occupancy times over beach sediments and time spent in close proximity to the site is also recorded for inclusion of external and inhalation radiation dose pathways. The integrated habits survey data may be combined with monitored environmental radionuclide concentrations to calculate total dose. The criteria for successful adoption of a method for this calculation were: Reproducibility can others easily use the approach and reassess doses? Rigour and realism how good is the match with reality?Transparency a measure of the ease with which others can understand how the calculations are performed and what they mean. Homogeneity is the group receiving the dose relatively homogeneous with respect to age, diet and those aspects that affect the dose received? Five methods of total dose calculation were compared and ranked according to their suitability. Each method was labelled (A to E) and given a short, relevant name for identification. The methods are described below; A) Individual doses to individuals are calculated and critical group selection is dependent on dose received. B) Individual Plus As in A, but consumption and occupancy rates for high dose is used to derive rates for application in

  5. Upper ankle joint space detection on low contrast intraoperative fluoroscopic C-arm projections

    Science.gov (United States)

    Thomas, Sarina; Schnetzke, Marc; Brehler, Michael; Swartman, Benedict; Vetter, Sven; Franke, Jochen; Grützner, Paul A.; Meinzer, Hans-Peter; Nolden, Marco

    2017-03-01

    Intraoperative mobile C-arm fluoroscopy is widely used for interventional verification in trauma surgery, high flexibility combined with low cost being the main advantages of the method. However, the lack of global device-to- patient orientation is challenging, when comparing the acquired data to other intrapatient datasets. In upper ankle joint fracture reduction accompanied with an unstable syndesmosis, a comparison to the unfractured contralateral site is helpful for verification of the reduction result. To reduce dose and operation time, our approach aims at the comparison of single projections of the unfractured ankle with volumetric images of the reduced fracture. For precise assessment, a pre-alignment of both datasets is a crucial step. We propose a contour extraction pipeline to estimate the joint space location for a prealignment of fluoroscopic C-arm projections containing the upper ankle joint. A quadtree-based hierarchical variance comparison extracts potential feature points and a Hough transform is applied to identify bone shaft lines together with the tibiotalar joint space. By using this information we can define the coarse orientation of the projections independent from the ankle pose during acquisition in order to align those images to the volume of the fractured ankle. The proposed method was evaluated on thirteen cadaveric datasets consisting of 100 projections each with manually adjusted image planes by three trauma surgeons. The results show that the method can be used to detect the joint space orientation. The correlation between angle deviation and anatomical projection direction gives valuable input on the acquisition direction for future clinical experiments.

  6. Paediatric pelvic imaging: optimisation of dose and technique using digital grid-controlled pulsed fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Waugh, R.; McCarty, M. [Div. of Radiology, South Cleveland Hospital, South Tees Acute Hospitals NHS Trust, Marton Road, Middlesbrough, Cleveland (United Kingdom); McCallum, H.M. [Regional Medical Physics Dept., South Cleveland Hospital, Middlesbrough (United Kingdom); Montgomery, R. [Dept. of Orthopaedics, South Tees Hospitals NITS Trust, Middlesbrough (United Kingdom); Aszkenasy, M. [Tees and North East Yorkshire NHS Trust, West Lane Hospital, Middlesbrough (United Kingdom)

    2001-05-01

    Background. An audit of paediatric pelvic radiographs identified deficiencies in gonad shield placement and radiographic technique. Objective. A technique using grid-controlled fluoroscopy (GCF), with hard copy images in frame grab and digital spot image (DSI) format was evaluated to optimise gonad shield placement and reduce the dose given to children with Perthes disease and Developmental Hip Dysplasia (DDH) attending for pelvic radiography. Materials and methods. Phantom and patient dose surveys of conventional and fluoroscopic techniques were carried out. Image quality and radiation dose were compared for the frame grab and DSI techniques. Retrospective evaluation was undertaken to compare their clinical acceptability. Results. Both fluoroscopic techniques gave considerably less radiation than conventional non-grid radiography (67-83 %, P < 0.05). The frame grab technique gave less radiation than DSI (P < 0.05). There was no significant difference in the clinical acceptability scores of the DSI and frame grab images. Conclusion. Fluoroscopy acquired images are now used since the fluoroscopic techniques give much less dose than conventional radiography and provide images of sufficient quality for clinical assessment. Indeed, as there was no significant difference in clinical usefulness between the frame grab and DSI techniques, it is planned to use frame grab alone, thus gaining additional dose saving. (orig.)

  7. Paediatric pelvic imaging: optimisation of dose and technique using digital grid-controlled pulsed fluoroscopy.

    Science.gov (United States)

    Waugh, R; McCallum, H M; McCarty, M; Montgomery, R; Aszkenasy, M

    2001-05-01

    An audit of paediatric pelvic radiographs identified deficiencies in gonad shield placement and radiographic technique. A technique using grid-controlled fluoroscopy (GCF), with hard copy images in frame grab and digital spot image (DSI) format was evaluated to optimise gonad shield placement and reduce the dose given to children with Perthes disease and Developmental Hip Dysplasia (DDH) attending for pelvic radiography. Phantom and patient dose surveys of conventional and fluoroscopic techniques were carried out. Image quality and radiation dose were compared for the frame grab and DSI techniques. Retrospective evaluation was undertaken to compare their clinical acceptability. Both fluoroscopic techniques gave considerably less radiation than conventional non-grid radiography (67-83%, P < 0.05). The frame grab technique gave less radiation than DSI (P < 0.05). There was no significant difference in the clinical acceptability scores of the DSI and frame grab images. Fluoroscopy acquired images are now used since the fluoroscopic techniques give much less dose than conventional radiography and provide images of sufficient quality for clinical assessment. Indeed, as there was no significant difference in clinical usefulness between the frame grab and DSI techniques, it is planned to use frame grab alone, thus gaining additional dose saving.

  8. Paediatric pelvic imaging: optimisation of dose and technique using digital grid-controlled pulsed fluoroscopy

    International Nuclear Information System (INIS)

    Waugh, R.; McCarty, M.; McCallum, H.M.; Montgomery, R.; Aszkenasy, M.

    2001-01-01

    Background. An audit of paediatric pelvic radiographs identified deficiencies in gonad shield placement and radiographic technique. Objective. A technique using grid-controlled fluoroscopy (GCF), with hard copy images in frame grab and digital spot image (DSI) format was evaluated to optimise gonad shield placement and reduce the dose given to children with Perthes disease and Developmental Hip Dysplasia (DDH) attending for pelvic radiography. Materials and methods. Phantom and patient dose surveys of conventional and fluoroscopic techniques were carried out. Image quality and radiation dose were compared for the frame grab and DSI techniques. Retrospective evaluation was undertaken to compare their clinical acceptability. Results. Both fluoroscopic techniques gave considerably less radiation than conventional non-grid radiography (67-83 %, P < 0.05). The frame grab technique gave less radiation than DSI (P < 0.05). There was no significant difference in the clinical acceptability scores of the DSI and frame grab images. Conclusion. Fluoroscopy acquired images are now used since the fluoroscopic techniques give much less dose than conventional radiography and provide images of sufficient quality for clinical assessment. Indeed, as there was no significant difference in clinical usefulness between the frame grab and DSI techniques, it is planned to use frame grab alone, thus gaining additional dose saving. (orig.)

  9. Dose assessment activities in the Republic of the Marshall Islands.

    Science.gov (United States)

    Simon, S L; Graham, J C

    1996-10-01

    Dose assessments, both retrospective and prospective, comprise one important function of a radiological study commissioned by the Republic of the Marshall Islands (RMI) government in late 1989. Estimating past or future exposure requires the synthesis of information from historical data, results from a recently completed field monitoring program, laboratory measurements, and some experimental studies. Most of the activities in the RMI to date have emphasized a pragmatic rather than theoretical approach. In particular, most of the recent effort has been expended on conducting an independent radiological monitoring program to determine the degree of deposition and the geographical extent of weapons test fallout over the nation. Contamination levels on 70% of the land mass of the Marshall Islands were unknown prior to 1994. The environmental radioactivity data play an integral role in both retrospective and prospective assessments. One recent use of dose assessment has been to interpret environmental measurements of radioactivity into annual doses that might be expected at every atoll. A second use for dose assessment has been to determine compliance with a dose action level for the rehabilitation of Rongelap Island. Careful examination of exposure pathways relevant to the island lifestyle has been necessary to accommodate these purposes. Examples of specific issues studied include defining traditional island diets as well as current day variations, sources of drinking water, uses of tropical plants including those consumed for food and for medicinal purposes, the nature and microvariability of plutonium particles in the soil and unusual pathways of exposure, e.g., that which might be associated with cooking and washing outdoors and inadvertent soil ingestion. A study on the prevalence of thyroid disease is also being conducted and the geographic pattern of disease may be useful as a bioindicator of the geographic pattern of exposure to radioiodine. Finally, an

  10. Clinical application of transnasal feeding tube placement under fluoroscopic guidance

    International Nuclear Information System (INIS)

    Ge Kunyuan; Ni Caifang; Liu Yizhi; Zhu Xiaoli; Zou Jianwei; Jin Yonghai; Chen Long; Sun Ge; Sun Lingfang; Zhang Dong

    2008-01-01

    Objective: To evaluate the feasibility and effectiveness of duodenal feeding tube placement under fluoroscopic guidance and its clinical application. Methods: The transnasal duodenal nutriment tubes placement under fluoroscopic guidance were performed in 59 patients from June 3th, 2003 to August 17th, 2007. The successful placement of the feeding tube was defined as that of the tube tip was fixed at or distal to the duodenojejunal junction. Results: 57 out of 59 patients were successfully managed by feeding tube placement, with primary successful rate of 96.6% (57/59). The remaining two failures were due to overdistention of the stomach and were further managed after gastrointestinal decompression thoroughly. The mean fluoroscopy time of the procedure was 17.8 minutes with no severe immediate or delayed complications. Conclusion: The transnasal duodenal nutrient feeding tube placement under fluoroscopic guidance is a safe,economic, and effective management for enteral nutrition, providing extensive clinical utilization. (authors)

  11. Dose-stress synergism in cancer risk assessment

    International Nuclear Information System (INIS)

    Pop-Jordanova, N.; Pop-Jordanov, J.

    2001-01-01

    Our hypothesis is that the relatively low risk of cancer or leukaemia from depleted uranium, as predicted by the World Health Organization and the International Atomic Energy Agency, is a result of neglecting the synergism between physico-chemical agents and psychological stress agents (here shortly denoted as dose-stress synergism). We use the modified risk assessment model that comprises a psycho-somatic extension, originally developed by us for assessing the risks of energy sources. Our preliminary meta-analysis of animal and human studies on cancers confirmed the existence of stress effects, including the amplifying synergism. Consequently, the psychological stress can increase the probability of even small toxic chemical or ionizing radiation exposure to produce malignancy. Such dose-stress synergism might influence the health risks among military personnel and the residents in the highly stressful environment in the Balkans. Further investigation is needed to estimate the order of magnitude of these combined effects in particular circumstances. (Original)

  12. Equine scintigraphy: assessment of the dose received by the personnel

    International Nuclear Information System (INIS)

    Clairand, I.; Bottollier, J.F.; Trompier, F.

    2003-01-01

    Following a request from the Permanent Secretary of the French Commission for Artificial Radioelements (CIREA) engaged to investigate a request for a licence related to a new scintigraphy unit dedicated to equidae, a dosimetric assessment concerning the personnel attending the examination was carried out. This scintigraphy unit depends on the Goustranville Centre for Imaging and Research on the Locomotive Diseases of Equidae (CIRALE) in the Calvados region. The dosimetric assessment was carried out for the different operators during the successive stages of the scintigraphic examination. Assuming 150 examinations per year, the annual equivalent dose to the fingers skin is 150 mSv maximum for the technologist and 2 mSv for the veterinary surgeon; the annual effective dose ranges from 0.15 to 0.45 mSv, depending on the operators. (authors)

  13. Biological dosimetry: chromosomal aberration analysis for dose assessment

    International Nuclear Information System (INIS)

    1986-01-01

    In view of the growing importance of chromosomal aberration analysis as a biological dosimeter, the present report provides a concise summary of the scientific background of the subject and a comprehensive source of information at the technical level. After a review of the basic principles of radiation dosimetry and radiation biology basic information on the biology of lymphocytes, the structure of chromosomes and the classification of chromosomal aberrations are presented. This is followed by a presentation of techniques for collecting blood, storing, transporting, culturing, making chromosomal preparations and scaring of aberrations. The physical and statistical parameters involved in dose assessment are discussed and examples of actual dose assessments taken from the scientific literature are given

  14. Skin dose assessment in routine personnel beta/gamma dosimetry

    International Nuclear Information System (INIS)

    Christensen, P.

    1980-01-01

    Three alternative methods are outlined by which substantial improvements of the capabilities of existing routine monitoring systems for skin dose assessment can be obtained. The introduction of a supplementary skin dosemeter may be an attractive method for systems with badges that have a capability for an additional dosemeter already built-in. The two-side reading method has limited possibilities because of reduced accuracy for mixed radiation and technical difficulties in using it for TLD systems with planchet heating. The use of a boron diffused LiF layer for skin dose assessment seems to be most attractive method since the only modification needed here is replacement of a dosemeter. However the study of this method is so far only in a preliminary stage and further investigations are needed. (U.K.)

  15. Assessment of dose measurement uncertainty using RisoScan

    International Nuclear Information System (INIS)

    Helt-Hansen, Jakob; Miller, Arne

    2006-01-01

    The dose measurement uncertainty of the dosimeter system RisoScan, office scanner and Riso B3 dosimeters has been assessed by comparison with spectrophotometer measurements of the same dosimeters. The reproducibility and the combined uncertainty were found to be approximately 2% and 4%, respectively, at one standard deviation. The subroutine in RisoScan for electron energy measurement is shown to give results that are equivalent to the measurements with a scanning spectrophotometer

  16. Assessment of dose measurement uncertainty using RisøScan

    DEFF Research Database (Denmark)

    Helt-Hansen, J.; Miller, A.

    2006-01-01

    The dose measurement uncertainty of the dosimeter system RisoScan, office scanner and Riso B3 dosimeters has been assessed by comparison with spectrophotometer measurements of the same dosimeters. The reproducibility and the combined uncertainty were found to be approximately 2% and 4%, respectiv......%, respectively, at one standard deviation. The subroutine in RisoScan for electron energy measurement is shown to give results that are equivalent to the measurements with a scanning spectrophotometer. (c) 2006 Elsevier Ltd. All rights reserved....

  17. Radiological environmental dose assessment methods and compliance dose results for 2015 operations at the Savannah River Site

    International Nuclear Information System (INIS)

    Jannik, G. T.; Dixon, K. L.

    2016-01-01

    This report presents the environmental dose assessment methods and the estimated potential doses to the offsite public from 2015 Savannah River Site (SRS) atmospheric and liquid radioactive releases. Also documented are potential doses from special-case exposure scenarios - such as the consumption of deer meat, fish, and goat milk.

  18. Radiological environmental dose assessment methods and compliance dose results for 2015 operations at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Jannik, G. T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Dixon, K. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-09-01

    This report presents the environmental dose assessment methods and the estimated potential doses to the offsite public from 2015 Savannah River Site (SRS) atmospheric and liquid radioactive releases. Also documented are potential doses from special-case exposure scenarios - such as the consumption of deer meat, fish, and goat milk.

  19. Biological dose assessment of 15 victims in Haerbin radiation accident

    International Nuclear Information System (INIS)

    Liu, Jian-xiang; Huang, Min-yan; Ruan, Jian-lei; Bai, Yu-shu; Xu, Su

    2008-01-01

    unstable aberrations were analyzed and biological dose was assessed according to the dose-effect curves built by our lab member. For micronucleus analysis, blood were added cytochalasin-B after culturing 40 hours. The doses were assessed according to the dose-effect curves built by our lab member. According to a human lymphocyte chromosome aberration and micronucleus analysis, the estimated maximum irradiation dose of 3 exposed patients is lower than 2 Gy, equal to the dose of once uneven total-body irradiation. In vitro dose-response calibration curves for (60)Co gamma rays have been established for unstable chromosome aberrations in human peripheral blood lymphocytes. The observed dose-response data were fitted to a linear quadratic model. The calibration curve parameters were used to estimate the equivalent whole-body dose and dose to the irradiated region in partial body irradiation of cancer patients. The derived partial body doses and fractions of lymphocytes irradiated were in agreement with those estimated from the radiotherapy regimes. (author)

  20. Cone beam computed tomography radiation dose and image quality assessments.

    Science.gov (United States)

    Lofthag-Hansen, Sara

    2010-01-01

    Diagnostic radiology has undergone profound changes in the last 30 years. New technologies are available to the dental field, cone beam computed tomography (CBCT) as one of the most important. CBCT is a catch-all term for a technology comprising a variety of machines differing in many respects: patient positioning, volume size (FOV), radiation quality, image capturing and reconstruction, image resolution and radiation dose. When new technology is introduced one must make sure that diagnostic accuracy is better or at least as good as the one it can be expected to replace. The CBCT brand tested was two versions of Accuitomo (Morita, Japan): 3D Accuitomo with an image intensifier as detector, FOV 3 cm x 4 cm and 3D Accuitomo FPD with a flat panel detector, FOVs 4 cm x 4 cm and 6 cm x 6 cm. The 3D Accuitomo was compared with intra-oral radiography for endodontic diagnosis in 35 patients with 46 teeth analyzed, of which 41 were endodontically treated. Three observers assessed the images by consensus. The result showed that CBCT imaging was superior with a higher number of teeth diagnosed with periapical lesions (42 vs 32 teeth). When evaluating 3D Accuitomo examinations in the posterior mandible in 30 patients, visibility of marginal bone crest and mandibular canal, important anatomic structures for implant planning, was high with good observer agreement among seven observers. Radiographic techniques have to be evaluated concerning radiation dose, which requires well-defined and easy-to-use methods. Two methods: CT dose index (CTDI), prevailing method for CT units, and dose-area product (DAP) were evaluated for calculating effective dose (E) for both units. An asymmetric dose distribution was revealed when a clinical situation was simulated. Hence, the CTDI method was not applicable for these units with small FOVs. Based on DAP values from 90 patient examinations effective dose was estimated for three diagnostic tasks: implant planning in posterior mandible and

  1. An airborne dispersion/dose assessment computer program. Phase 1

    International Nuclear Information System (INIS)

    Scott, C.K.; Kennedy, E.R.; Hughs, R.

    1991-05-01

    The Atomic Energy Control Board (AECB) staff have a need for an airborne dispersion-dose assessment computer programme for a microcomputer. The programme must be capable of analyzing the dispersion of both radioactive and non-radioactive materials. A further requirement of the programme is that it be implemented on the AECB complex of microcomputers and that it have an advanced graphical user interface. A survey of computer programs was conducted to determine which, if any, could meet the AECB's requirements in whole or in part. Ten programmes were selected for detailed review including programs for nuclear and non-radiological emergencies. None of the available programmes for radiation dose assessment meets all the requirements for reasons of user interaction, method of source term estimation or site specificity. It is concluded that the best option for meeting the AECB requirements is to adopt the CAMEO programme (specifically the ALOHA portion) which has a superior graphical user interface and add the necessary models for radiation dose assessment

  2. Assessment and recording of radiation doses to workers

    International Nuclear Information System (INIS)

    1986-01-01

    The assessment and recording of the radiation exposure of workers in activities involving radiation risks are required for demonstrating compliance with institutional dose limitations and for a number of other complementary purposes. A significant proportion of the labor force involved in radiation work is currently represented by those specialised workers who operate as itinerant contractors for different nuclear installations and in different countries. In order to ensure that the exposure of these workers is adequately and consistently controlled and kept within acceptable limits, there is a need for the criteria and methods for dose assessment and recording to be harmonised throughout the different countries. An attempt in that direction has been made in this report, which has been prepared by a group of experts convened by the Committee on Radiation Protection and Public Health of the OECD Nuclear Energy Agency. Its primary purpose is to describe recommended technical procedures for an unified approach to the assessment and recording of worker doses. The report is published under the responsibility of the Secretary-General of the OECD, and does not commit Member governments

  3. Assessment of dose in cervical vertebrae radiographic examinations

    International Nuclear Information System (INIS)

    Owrnasir, Wafa Fadol Orsud

    2014-12-01

    Reference dose levels provide a framework to reduce doses variability and aid in the optimization of radiation protection.This study was performed in Khartoum Teaching Hospital in period of January to June 2014. This study performed to assess the entrance surface dose ( ESD) received in Cervical Vertebrae radiographic examination and to analyze effective dose distributions among radiological departments under study. The study was performed in Khartoum Teaching Hospital, covering two x-ray units and a sample of 64 patients. The following parameter were recorded; age, weight, height, body mass index (BMI) derived from weight (kg) and height (m) and exposure factors. The dose was measured for Cervical Vertebrae x-ray examinations, the entrance surface dose (ESD) values were estimated from the x-ray tube output parameters for Cervical Vertebrae AP and lateral examinations. The ESD values were then calculated using IAEA calculation methods. The results of ESD values calculated showed than patient exposure were within the normal range of exposure. The mean ED values calculated were ( 3.85 ±0.04) and (4.02 ±0.05) mGy for Cervical Vertebrae AP and lateral examinations, respectively in department Na1 and (3.99± 0.15) and (4.23± 0.34) mGy, for Cervical Vertebrae Ap and lateral examinations respectively in department Na2, the IAEA standard value of ESD for cervical equal (7), (20) mGy AP and LAT, Further studies are recommended with more number of patients and using more than two modalities for comparison. (Author)

  4. Proposal of a dosemeter for skin beta radiation dose assessment

    International Nuclear Information System (INIS)

    Rosa, L.A.R. da; Caldas, L.V.E.

    1987-08-01

    Beta radiation is, undoubtedly, less penetrating than X or gamma radiation. Thus, beta radiation sources external to the human body do not cause a significant irradiation of its deeper tissues. However, in some cases, they may contribute in a very important way to the irradiation of the lens of the eyes and, mainly, of the skin. Specially, the hands and finger tips may receive a high dose. In this work some relevant aspects of the individual monitoring in beta radiation fields are discussed and the importance of monitoring this kind of radiation in some activities where the skin absorbed dose may be a limiting factor is evidenced. The main characteristics of the thermoluminescent (TL) response of ultra-thin CaSO 4 : Dy detectors (UT-CaSO 4 : Dy) in the detection of this kind of radiation are also studied. The irradiation are performed with 90 Sr 90 Y, 204 TI and 147 Pm sources. The reproducibility, linearity, dependence on the absorbed dose rate, optical fading, energy and angular dependences of the detector TL responce are investigated. Transmission factors for different thicknesses of tissue equivalent material are obtained for the TL detectors using the three available beta sources. Based on the results obtained, a dosemeter for skin beta radiation absorbed dose assessment with an energy dependence better than 12% is proposed. (Author) [pt

  5. Variations of Patient Doses in Interventional Examinations at Different Angiographic Units

    International Nuclear Information System (INIS)

    Bor, Dogan; Toklu, Tuerkay; Olgar, Turan; Sancak, Tanzer; Cekirge, Saruhan; Onal, Baran; Bilgic, Sadik

    2006-01-01

    Purpose. We analyzed doses for various angiographic procedures using different X-ray systems in order to assess dose variations. Methods. Dose-area product (DAP), skin doses from thermoluminescent dosimeters and air kerma measurements of 308 patients (239 diagnostic and 69 interventional) were assessed for five different angiographic units. All fluoroscopic and radiographic exposure parameters were recorded online for single and multiprojection studies. Radiation outputs of each X-ray system were also measured for all the modes of exposure using standard protocols for such measurements. Results. In general, the complexity of the angiographic procedure was found to be the most important reason for high radiation doses. Skill of the radiologist, management of the exposure parameters and calibration of the system are the other factors to be considered. Lateral cerebral interventional studies carry the highest risk for deterministic effects on the lens of the eye. Effective doses were calculated from DAP measurements and maximum fatal cancer risk factors were found for carotid studies. Conclusions. Interventional radiologists should measure patient doses for their examinations. If there is a lack of necessary instrumentation for this purpose, then published dose reports should be used in order to predict the dose levels from some of the exposure parameters. Patient dose information should include not only the measured quantity but also the measured radiation output of the X-ray unit and exposure parameters used during radiographic and fluoroscopic exposures

  6. 21 CFR 892.1650 - Image-intensified fluoroscopic x-ray system.

    Science.gov (United States)

    2010-04-01

    ... fluoroscopic x-ray system. (a) Identification. An image-intensified fluoroscopic x-ray system is a device... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Image-intensified fluoroscopic x-ray system. 892... equipment, patient and equipment supports, component parts, and accessories. (b) Classification. Class II...

  7. 21 CFR 892.1660 - Non-image-intensified fluoroscopic x-ray system.

    Science.gov (United States)

    2010-04-01

    ... fluoroscopic x-ray system. (a) Identification. A non-image-intensified fluoroscopic x-ray system is a device... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Non-image-intensified fluoroscopic x-ray system... display equipment, patient and equipment supports, component parts, and accessories. (b) Classification...

  8. Internal dose assessment in nuclear medicine: fetal doses due to radiopharmaceutical administration to the mother

    International Nuclear Information System (INIS)

    Rojo, Ana M.; Michelin, Severino C.

    2004-01-01

    The objective of this publication is to present a guideline for the dose assessment through a comprehensive introduction of knowledge on ionizing radiation, radiation protection during pregnancy and fetal dosimetry for physician and other professionals involved in nuclear medicine practices. It contains tables with recommended dose estimates at all stages of pregnancy for many radiopharmaceuticals. Compounds for which some information was available regarding placental crossover are shown in shaded rows. It includes the most common diagnostic and therapy practices in nuclear medicine considering the four radioactive isotopes selected: 99m Tc, 131 I, 201 Tl and 67 Ga. There is a special case included, it is when conception occurs after the iodine has been administered. In almost every case, the diagnostic benefit to the mother outweighs the risk of any irradiation of the fetus. However, there is one situation in which severe fetal injury can be incurred from administering a radiopharmaceutical to the mother, and that is use of iodine-131 therapy for ablation of the thyroid in cases of hyperthyroidism or carcinoma. Radioactive iodine readily crosses the placenta and concentrates in the fetal thyroid, where, because of its small organ mass, high radiation doses are received. (author)

  9. A phantom for assessing the personal dose equivalent, HP(10)

    International Nuclear Information System (INIS)

    Santoro, C.; Filho, J.A

    2013-01-01

    Characteristics of a phantom designed to evaluate the personal dose equivalent, H P (10), and appropriate for photographic dosimetry are presented. It is called HP(10) phantom due to cavities constructed to insert dosimetric films at a depth of 10 mm. The H P (10) phantom is irradiated with ionizing radiation energy, E, from 45 to 1250 keV, with doses ranging from 0.2 to 50 mSv. It is positioned in the direction α = 0 °, and the radiation field focusing perpendicular to its front surface. So, are established calibration curves of dosimeters in the position conventionally true and quantities H P (10). It made a comparison between the responses obtained with the H P (10) phantom and responses obtained when using the calibration procedure recommended by ISO dosimeters. The ISO recommends getting the air kerma, Ka, for photons at test point of the radiation field by an ionization chamber. And through conversion coefficients, h pK (10; E, α), becomes the air kerma for H P (10). The ISO 4037-3 recommendation has been studied by researchers to ensure that the low energy spectral differences occur in radiation fields which are generated by various X-ray equipment, and induce changes in the percentages of conversion coefficients on the order of 10% to 90% . On the basis of the recommendations ISO, this article develops phantom able to assess the dose to the influence of scattering and absorption of radiation, its implications with respect to dosimetry, providing improvement in the assessment of doses. (author)

  10. Smartphone apps for calculating insulin dose: a systematic assessment.

    Science.gov (United States)

    Huckvale, Kit; Adomaviciute, Samanta; Prieto, José Tomás; Leow, Melvin Khee-Shing; Car, Josip

    2015-05-06

    Medical apps are widely available, increasingly used by patients and clinicians, and are being actively promoted for use in routine care. However, there is little systematic evidence exploring possible risks associated with apps intended for patient use. Because self-medication errors are a recognized source of avoidable harm, apps that affect medication use, such as dose calculators, deserve particular scrutiny. We explored the accuracy and clinical suitability of apps for calculating medication doses, focusing on insulin calculators for patients with diabetes as a representative use for a prevalent long-term condition. We performed a systematic assessment of all English-language rapid/short-acting insulin dose calculators available for iOS and Android. Searches identified 46 calculators that performed simple mathematical operations using planned carbohydrate intake and measured blood glucose. While 59% (n = 27/46) of apps included a clinical disclaimer, only 30% (n = 14/46) documented the calculation formula. 91% (n = 42/46) lacked numeric input validation, 59% (n = 27/46) allowed calculation when one or more values were missing, 48% (n = 22/46) used ambiguous terminology, 9% (n = 4/46) did not use adequate numeric precision and 4% (n = 2/46) did not store parameters faithfully. 67% (n = 31/46) of apps carried a risk of inappropriate output dose recommendation that either violated basic clinical assumptions (48%, n = 22/46) or did not match a stated formula (14%, n = 3/21) or correctly update in response to changing user inputs (37%, n = 17/46). Only one app, for iOS, was issue-free according to our criteria. No significant differences were observed in issue prevalence by payment model or platform. The majority of insulin dose calculator apps provide no protection against, and may actively contribute to, incorrect or inappropriate dose recommendations that put current users at risk of both catastrophic overdose and more

  11. ARAC: A flexible real-time dose consequence assessment system

    International Nuclear Information System (INIS)

    Ellis, J.S.; Sullivan, T.J.

    1993-01-01

    Since its beginning, the Atmospheric Release Advisory Capability (ARAC), an emergency radiological dose assessment service of the US Government, has been called on to do consequence assessments for releases into the atmosphere of radionuclides and a variety of other substances. Some of the more noteworthy emergency responses have been for the Three Mile Island and Chernobyl nuclear power reactor accidents, and more recently, for a cloud of gases from a rail-car spill into the Sacramento river of the herbicide metam sodium, smoke from hundreds of burning oil wells in Kuwait, and ash clouds from the eruption of Mt. Pinatubo. The spatial scales of these responses range from local, to regional, to global, and the response periods from hours, to weeks, to months. Because of the variety of requirements of each unique assessment, ARAC has developed and maintains a flexible system of people, computer software and hardware

  12. Experiences upgrading a fluoroscopic system to digital specifications

    International Nuclear Information System (INIS)

    Fox, T.; Fenzl, G.

    1995-01-01

    In 1993, an undertable fluoroscopic system was retrofitted with a Fluorospot HC digital system at the radiological clinic of the Knappschaftskrankenhaus in Puettlingen, Germany. The experiences and possibilities resulting from this digital upgrade are related by the authors, whose narrative is also accompanied by examples of clinical images. The costs involved are also discussed in this article. (orig.)

  13. Adjustable radiation protection device of the fluoroscope DG 10

    International Nuclear Information System (INIS)

    Hoermann, D.

    1980-01-01

    In cooperation with the 'VEB Transformatoren- und Roentgenwerk Hermann Matern', Dresden, an adjustable radiation protection device has been developed. This supplementary equipment for fluoroscopes ensures a sufficient protection of the gonads against undesirable X radiation, can be handled easily and does not annoy patients, esp. children

  14. Measurements for testing of fluoroscopic screens, including the photofluorographic units

    International Nuclear Information System (INIS)

    Balfanz, R.

    1986-01-01

    Image quality control measurements for fluoroscopic screens and photofluorographs have shown that both types of equipment have a long operating life, so that constancy and technical performance tests are absolutely necessary. It is recommended to conclude in-service maintenance contracts with the manufacturers. (DG) [de

  15. Development of Landscape Dose Factors for dose assessments in SR-Can

    Energy Technology Data Exchange (ETDEWEB)

    Avila, Rodolfo; Ekstroem, Per-Anders [Facilia AB, Bromma (Sweden); Kautsky, Ulrik [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    2006-08-15

    In previous safety assessments Ecosystem Dose Factors (EDFs), were derived from estimates of doses to the most exposed group resulting from constant unit radionuclide release rates over 10,000 years to various ecosystem types, e.g. mires, agricultural lands, lakes and marine ecosystems. A number of limitations of the EDF approach have been identified. The objectives of this report is to further develop the EDF approach, in order to resolve the identified limitations, and to use the improved approach for deriving Dose Conversion Factors for use in the SR-Can risk assessments. The Dose Conversion Factors derived in this report are named Landscape Dose Factors (LDFs). It involves modelling the fate of the radionuclides in the whole landscape, which develops from a sea to a inland situation during 20,000 years. Both candidate sites studies in SR-Can, Forsmark and Laxemar, are included in the study. As a basis for the modelling, the period starting at the beginning of the last interglacial (8,000 BC) is used, over which releases from a hypothetical repository were assumed to take place. For the present temperate period, the overall development of the biosphere at each site is outlined in a 1,000 year perspective and beyond, essentially based on the ongoing shoreline displacement and the understanding on the impact this has on the biosphere. The past development, i.e. from deglaciation to the present time, is inferred from geological records and associated reconstructions of the shore-line. For each time step of 1,000 years, the landscape at the site is described as a number of interconnected biosphere objects constituting an integrated landscape model of each site. The water fluxes through the objects were estimated from the average run-off at the site, the areas of the objects and their associated catchment areas. Radionuclides in both dissolved and particulate forms were considered in the transport calculations. The transformation between ecosystems was modelled as

  16. Non-human biota dose assessment. Sensitivity analysis and knowledge quality assessment

    International Nuclear Information System (INIS)

    Smith, K.; Robinson, C.; Jackson, D.; La Cruz, I. de; Zinger, I.; Avila, R.

    2010-10-01

    This report provides a summary of a programme of work, commissioned within the BIOPROTA collaborative forum, to assess the quantitative and qualitative elements of uncertainty associated with biota dose assessment of potential impacts of long-term releases from geological disposal facilities (GDF). Quantitative and qualitative aspects of uncertainty were determined through sensitivity and knowledge quality assessments, respectively. Both assessments focused on default assessment parameters within the ERICA assessment approach. The sensitivity analysis was conducted within the EIKOS sensitivity analysis software tool and was run in both generic and test case modes. The knowledge quality assessment involved development of a questionnaire around the ERICA assessment approach, which was distributed to a range of experts in the fields of non-human biota dose assessment and radioactive waste disposal assessments. Combined, these assessments enabled critical model features and parameters that are both sensitive (i.e. have a large influence on model output) and of low knowledge quality to be identified for each of the three test cases. The output of this project is intended to provide information on those parameters that may need to be considered in more detail for prospective site-specific biota dose assessments for GDFs. Such information should help users to enhance the quality of their assessments and build greater confidence in the results. (orig.)

  17. Guidance on internal dose assessments from monitoring data (Project IDEAS)

    International Nuclear Information System (INIS)

    Doerfel, H.; Andrasi, A.; Bailey, M.; Berkovski, V.; Castellani, M.; Hurtgen, C.; Jourdain, R.; Le Guen, B.

    2003-01-01

    Several international intercomparison exercises on intake and internal dose assessments from monitoring data led to the conclusion that the results calculated by different participants varied significantly mainly to the broad variety of methods and assumptions applied in the assessment procedure. Based on these experiences the need of harmonisation of the procedures has been formulated as an EU research project under the 5th Framework Programme, with the aim of developing general guidelines for standardising assessments of intakes and internal doses. In the IDEAS project, eight institutions from seven European countries are participating, also using inputs from internal dosimetry professionals from across Europe to ensure broad consensus in the outcome of the project. To ensure that the guidelines are applicable to a wide range of practical situations, the first step will be to compile a database on well documented cases of internal contamination. In parallel, an improved version of existing software will be developed and distributed to the partners for further use. Many cases from the database will be evaluated independently by more partners using the same software and the results will be discussed and the draft guidelines prepared. The guidelines will then be revised and refined on the basis of the experiences and discussions of two workshops, and an inter-comparison exercise organised in the frame of the project which will be open to all internal dosimetry professionals. (author)

  18. Clinical comparison between 100 mm photofluorography and digital (1024/sup 2/) fluoroscopic image acquisition

    International Nuclear Information System (INIS)

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

    1986-01-01

    The authors describe current work in progress in which a clinical image can be recorded on both 100-mm film and a 1,024/sup 2/ image store with the same exposure. The 100-mm film is exposed in the usual manner. However, the same radiation exposure is utilized by the optics of the beam splitter to transfer the output image of the intensifier into a 1,024/sup 2/ image store and thence to hard copy by multiformat camera or laser printer. Comparative phantom and clinical images will be presented, along with observations on dose rates needed for diagnostic digital imaging. Use of this system may allow fluoroscopic dose rates to be reduced

  19. Mixed species radioiodine air sampling readout and dose assessment system

    International Nuclear Information System (INIS)

    Distenfeld, C.H.; Klemish, J.R. Jr.

    1978-01-01

    This invention provides a simple, reliable, inexpensive and portable means and method for determining the thyroid dose rate of mixed airborne species of solid and gaseous radioiodine without requiring highly skilled personnel, such as health physicists or electronics technicians. To this end, this invention provides a means and method for sampling a gas from a source of a mixed species of solid and gaseous radioiodine for collection of the mixed species and readout and assessment of the emissions therefrom by cylindrically, concentrically and annularly molding the respective species around a cylindrical passage for receiving a conventional probe-type Geiger-Mueller radiation detector

  20. Fluoroscopically guided closed reduction and internal fixation of fractures of the lateral portion of the humeral condyle: prospective clinical study of the technique and results in ten dogs.

    Science.gov (United States)

    Cook, J L; Tomlinson, J L; Reed, A L

    1999-01-01

    To report a technique for fluoroscopically guided closed reduction with internal fixation of fractures of the lateral portion of the humeral condyle (FLHC) and determine the long-term results in 10 clinical cases. Prospective clinical case study. Ten dogs with 11 fractures. Fractures of the lateral portion of the humeral condyle were stabilized with transcondylar screws and Kirschner wires. Closed reduction and implant placement were achieved using intraoperative fluoroscopic guidance. After fracture repair, postoperative radiographs were evaluated for articular alignment and implant placement. Dogs were evaluated after surgery by means of lameness scores, elbow range of motion (ROM), radiographic assessment, and owner evaluation of function. Postoperative reduction was considered anatomic in 6 fractures with all other fractures having ROM values between affected and unaffected elbows. All of the dogs in this study regained 90-100% of full function, based on owner assessment. Fluoroscopic guidance for closed reduction and internal fixation of FLHC in dogs is an effective technique.

  1. The assessment of collective dose for travellers travelling by water

    International Nuclear Information System (INIS)

    Yue Qingyu; Jiang Ping; Jin Hua

    1992-06-01

    The major contribution to the various radiation exposure received by mankind comes from natural radiation. Some environmental change caused by human beings and some activities of mankind may decrease or increase the radiation exposure level from natural radiation. People travelling by air will receive more exposure dose and by water will receive less. China has about 18000 km coast line and the inland water transportation is very flourishing. According to statistic data from Ministry of Transportation in 1988, the turnover in that year was about 2 x 10 10 man.km. The total number of fisherman for inshore fishing was nearly two million reported by Ministry of Farming, Animal Husbandry and Fishery. We measured 212 points in six typical shipping lines of inshore lines and inland rivers, and the distance was 5625 km. The average natural radiation exposure dose rate received by travellers in each shipping line was calculated. From that the assessment of collective dose equivalent for passengers by water and fishermen was derived. The value is 32.7 man.Sv for passengers and 265.3 man.Sv for fishermen

  2. The assessment of collective dose for travellers travelling by water

    International Nuclear Information System (INIS)

    Yue Qingyu; Jian Ping; Jin Hua

    1994-01-01

    The major contribution to various radiation exposure received by mankind comes from natural radiation. Some environmental change caused by human beings and some activities of mankind may decrease or increase the radiation exposure level from natural radiation. China has about 18000 km coast line and the inland water transportation is very flourishing. According to statistic data from Ministry of Transportation in 1988, the turnover in that year was about 2 x 10 10 man·km. The total number of fisherman for inshore fishing was nearly two millions reported by Ministry of Farming, Animal Husbandry and Fishery. We measured exposure dose rates over 212 points in six typical shipping lines of inshore lines and inland rivers, and the distance was 5625 km. The average natural radiation exposure dose rate received by travellers in each shipping line was calculated. From that the assessment of collective dose equivalent for passengers by water and fishermen was derived. The value is 32.7 man·Sv for passengers and 265.3 man·Sv for fishermen

  3. Relationship between dose and risk, and assessment of carcinogenic risks associated with low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Tubiana, M.; Aurengo, A.

    2005-01-01

    This report raises doubts on the validity of using LNT (linear no-threshold) relationship for evaluating the carcinogenic risk of low doses (< 100 mSv) and even more for very low doses (< 10 mSv). The LNT concept can be a useful pragmatic tool for assessing rules in radioprotection for doses above 10 mSv; however since it is not based on biological concepts of our current knowledge, it should not be used without precaution for assessing by extrapolation the risks associated with low and even more so, with very low doses (< 10 mSv), especially for benefit-risk assessments imposed on radiologists by the European directive 97-43. The biological mechanisms are different for doses lower than a few dozen mSv and for higher doses. The eventual risks in the dose range of radiological examinations (0.1 to 5 mSv, up to 20 mSv for some examinations) must be estimated taking into account radiobiological and experimental data. An empirical relationship which has been just validated for doses higher than 200 mSv may lead to an overestimation of risks (associated with doses one hundred fold lower), and this overestimation could discourage patients from undergoing useful examinations and introduce a bias in radioprotection measures against very low doses (< 10 mSv). Decision makers confronted with problems of radioactive waste or risk of contamination, should re-examine the methodology used for the evaluation of risks associated with very low doses and with doses delivered at a very low dose rate. This report confirms the inappropriateness of the collective dose concept to evaluate population irradiation risks

  4. Cytogenetic analysis for radiation dose assessment. A manual

    International Nuclear Information System (INIS)

    2001-01-01

    Chromosome aberration analysis is recognized as a valuable dose assessment method which fills a gap in dosimetric technology, particularly when there are difficulties in interpreting the data, in cases where there is reason to believe that persons not wearing dosimeters have been exposed to radiation, in cases of claims for compensation for radiation injuries that are not supported by unequivocal dosimetric evidence, or in cases of exposure over an individual's working lifetime. The IAEA has maintained a long standing involvement in biological dosimetry commencing in 1978. This has been via a sequence of Co-ordinated Research Programmes (CRPs), the running of Regional Training Courses, the sponsorship of individual training fellowships and the provision of necessary equipment to laboratories in developing Member States. The CRP on the 'Use of Chromosome Aberration Analysis in Radiation Protection' was initiated by IAEA in 1982. It ended with the publication of the IAEA Technical Report Series No. 260, titled 'Biological Dosimetry: Chromosomal Aberration Analysis for Dose Assessment' in 1986. The overall objective of the CRP (1998-2000) on 'Radiation Dosimetry through Biological Indicators' is to review and standardize the available methods and amend the above mentioned previous IAEA publication with current techniques on cytogenetic bioindicators which may be of practical use in biological dosimetry worldwide. An additional objective is to identify promising cytogenetic techniques to provide Member States with up to date and generally agreed advice regarding the best focus for research and suggestions for the most suitable techniques for near future practice in biodosimetry. This activity is in accordance with the International Basic Safety Standards (BSS) published in 1996. To pursue this task the IAEA has conducted a Research Co-ordination Meeting (Budapest, Hungary, June 1998) with the participation of senior scientists of 24 biodosimetry laboratories to discuss

  5. ARAC: a computer-based emergency dose-assessment service

    International Nuclear Information System (INIS)

    Sullivan, T.J.

    1990-01-01

    Over the past 15 years, the Lawrence Livermore National Laboratory's Atmospheric Release Advisory Capability (ARAC) has developed and evolved a computer-based, real-time, radiological-dose-assessment service for the United States Departments of Energy and Defense. This service is built on the integrated components of real-time computer-acquired meteorological data, extensive computer databases, numerical atmospheric-dispersion models, graphical displays, and operational-assessment-staff expertise. The focus of ARAC is the off-site problem where regional meteorology and topography are dominant influences on transport and dispersion. Through application to numerous radiological accidents/releases on scales from small accidental ventings to the Chernobyl reactor disaster, ARAC has developed methods to provide emergency dose assessments from the local to the hemispheric scale. As the power of computers has evolved inversely with respect to cost and size, ARAC has expanded its service and reduced the response time from hours to minutes for an accident within the United States. Concurrently the quality of the assessments has improved as more advanced models have been developed and incorporated into the ARAC system. Over the past six years, the number of directly connected facilities has increased from 6 to 73. All major U.S. Federal agencies now have access to ARAC via the Department of Energy. This assures a level of consistency as well as experience. ARAC maintains its real-time skills by participation in approximately 150 exercises per year; ARAC also continuously validates its modeling systems by application to all available tracer experiments and data sets

  6. Fluoroscopic-guided radiofrequency ablation of the basivertebral nerve: application and analysis with multiple imaging modalities in an ovine model (Invited Paper)

    Science.gov (United States)

    Bergeron, Jeffrey A.; Eskey, Cliff J.; Attawia, Mohammed; Patel, Samit J.; Ryan, Thomas P.; Pellegrino, Richard; Sutton, Jeffrey; Crombie, John; Paul, B. T.; Hoopes, P. J.

    2005-04-01

    Pathologic involvement of the basivertebral nerve, an intraosseous vertebral nerve found in humans and most mammalian species, may play a role in some forms of back pain. This study was designed to assess the feasibility and effects of the percutaneous delivery of radiofrequency (RF) energy to thermally ablate the basivertebral nerve in the lumbar vertebrae of mature sheep. Using fluoroscopic guidance, a RF bipolar device was placed and a thermal dose delivered to lumbar vertebral bodies in sheep. Post-treatment assessment included multiple magnetic resonance imaging (MRI) techniques and computed tomography (CT). These data were analyzed and correlated to histopathology and morphometry findings to describe the cellular and boney structural changes resulting from the treatment. Imaging modalities MRI and CT can be implemented to non-invasively describe treatment region and volume, marrow cellular effects, and bone density alterations immediately following RF treatment and during convalescence. Such imaging can be utilized to assess treatment effects and refine the thermal dose to vertebral body volume ratio used in treatment planning. This information will be used to improve the therapeutic ratio and develop a treatment protocol for human applications.

  7. Assessing the effect of electron density in photon dose calculations

    International Nuclear Information System (INIS)

    Seco, J.; Evans, P. M.

    2006-01-01

    Photon dose calculation algorithms (such as the pencil beam and collapsed cone, CC) model the attenuation of a primary photon beam in media other than water, by using pathlength scaling based on the relative mass density of the media to water. In this study, we assess if differences in the electron density between the water and media, with different atomic composition, can influence the accuracy of conventional photon dose calculations algorithms. A comparison is performed between an electron-density scaling method and the standard mass-density scaling method for (i) tissues present in the human body (such as bone, muscle, etc.), and for (ii) water-equivalent plastics, used in radiotherapy dosimetry and quality assurance. We demonstrate that the important material property that should be taken into account by photon dose algorithms is the electron density, and not the mass density. The mass-density scaling method is shown to overestimate, relative to electron-density predictions, the primary photon fluence for tissues in the human body and water-equivalent plastics, where 6%-7% and 10% differences were observed respectively for bone and air. However, in the case of patients, differences are expected to be smaller due to the large complexity of a treatment plan and of the patient anatomy and atomic composition and of the smaller thickness of bone/air that incident photon beams of a treatment plan may have to traverse. Differences have also been observed for conventional dose algorithms, such as CC, where an overestimate of the lung dose occurs, when irradiating lung tumors. The incorrect lung dose can be attributed to the incorrect modeling of the photon beam attenuation through the rib cage (thickness of 2-3 cm in bone upstream of the lung tumor) and through the lung and the oversimplified modeling of electron transport in convolution algorithms. In the present study, the overestimation of the primary photon fluence, using the mass-density scaling method, was shown

  8. Risk and dose assessment methods in gamma knife QA

    International Nuclear Information System (INIS)

    Banks, W.W.; Jones, E.D.; Rathbun, P.

    1992-10-01

    Traditional methods used in assessing risk in nuclear power plants may be inappropriate to use in assessing medical radiation risks. The typical philosophy used in assessing nuclear reactor risks is machine dominated with only secondary attention paid to the human component, and only after critical machine failure events have been identified. In assessing the risk of a misadministrative radiation dose to patients, the primary source of failures seems to stem overwhelmingly, from the actions of people and only secondarily from machine mode failures. In essence, certain medical misadministrations are dominated by human events not machine failures. Radiological medical devices such as the Leksell Gamma Knife are very simple in design, have few moving parts, and are relatively free from the risks of wear when compared with a nuclear power plant. Since there are major technical differences between a gamma knife and a nuclear power plant, one must select a particular risk assessment method which is sensitive to these system differences and tailored to the unique medical aspects of the phenomena under study. These differences also generate major shifts in the philosophy and assumptions which drive the risk assessment (Machine-centered vs Person-centered) method. We were prompted by these basic differences to develop a person-centered approach to risk assessment which would reflect these basic philosophical and technological differences, have the necessary resolution in its metrics, and be highly reliable (repeatable). The risk approach chosen by the Livermore investigative team has been called the ''Relative Risk Profile Method'' and has been described in detail by Banks and Paramore, (1983)

  9. Dose measurement, its distribution and individual external dose assessments of inhabitants in the high background radiation areas in China

    International Nuclear Information System (INIS)

    Morishima, Hiroshige; Koga, Taeko; Tatsumi, Kusuo; Nakai, Sayaka; Sugahara, Tsutomu; Yuan Yongling; Wei Luxin

    2000-01-01

    As a part of the China-Japan cooperative research on natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external exposure to natural radiation in the high background radiation areas (HBRA) of Yangjiang in Guangdong province and in the control areas (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by personal dosimeters, an indirect method was applied in which the exposed individual doses were estimated from the environmental radiation doses measured by survey meters and the occupancy factors of each hamlet. We analyzed the dose in the hamlets and the variation in the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and several hamlets of different dose levels in HBRA and Hampizai hamlet in CA. With these parameters, we estimated individual dose rates and compared them with those obtained from direct measurement using dosimeters carried by selected individuals. The results obtained are as follows. The environmental radiation doses are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiations. The indoor radiation doses were due to exposure from the natural radioactive nuclides in the building materials and were about two times as large as the outdoor radiation doses. The difference between indoor and outdoor doses was not observed in CA. The occupancy factor was influenced by the age of individuals and by the season of the year. The occupancy factor was higher for infants and aged individuals than for other age groups. This lead to higher dose rates of exposure to those age groups. A good correlation was observed between the dose assessed indirectly and that measured directly and the

  10. Dose measurement, its distribution and individual external dose assessments of inhabitants in the high background radiation areas in China

    Energy Technology Data Exchange (ETDEWEB)

    Morishima, Hiroshige; Koga, Taeko [Kinki Univ., Higashi-Osaka, Osaka (Japan). Atomic Energy Research Inst.; Tatsumi, Kusuo; Nakai, Sayaka; Sugahara, Tsutomu; Yuan Yongling; Wei Luxin

    2000-10-01

    As a part of the China-Japan cooperative research on natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external exposure to natural radiation in the high background radiation areas (HBRA) of Yangjiang in Guangdong province and in the control areas (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by personal dosimeters, an indirect method was applied in which the exposed individual doses were estimated from the environmental radiation doses measured by survey meters and the occupancy factors of each hamlet. We analyzed the dose in the hamlets and the variation in the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and several hamlets of different dose levels in HBRA and Hampizai hamlet in CA. With these parameters, we estimated individual dose rates and compared them with those obtained from direct measurement using dosimeters carried by selected individuals. The results obtained are as follows. The environmental radiation doses are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiations. The indoor radiation doses were due to exposure from the natural radioactive nuclides in the building materials and were about two times as large as the outdoor radiation doses. The difference between indoor and outdoor doses was not observed in CA. The occupancy factor was influenced by the age of individuals and by the season of the year. The occupancy factor was higher for infants and aged individuals than for other age groups. This lead to higher dose rates of exposure to those age groups. A good correlation was observed between the dose assessed indirectly and that measured directly and the

  11. Rationale and design of the NO-PARTY trial: near-zero fluoroscopic exposure during catheter ablation of supraventricular arrhythmias in young patients.

    Science.gov (United States)

    Casella, Michela; Dello Russo, Antonio; Pelargonio, Gemma; Bongiorni, Maria Grazia; Del Greco, Maurizio; Piacenti, Marcello; Andreassi, Maria Grazia; Santangeli, Pasquale; Bartoletti, Stefano; Moltrasio, Massimo; Fassini, Gaetano; Marini, Massimiliano; Di Cori, Andrea; Di Biase, Luigi; Fiorentini, Cesare; Zecchi, Paolo; Natale, Andrea; Picano, Eugenio; Tondo, Claudio

    2012-10-01

    Radiofrequency catheter ablation is the mainstay of therapy for supraventricular tachyarrhythmias. Conventional radiofrequency catheter ablation requires the use of fluoroscopy, thus exposing patients to ionising radiation. The feasibility and safety of non-fluoroscopic radiofrequency catheter ablation has been recently reported in a wide range of supraventricular tachyarrhythmias using the EnSite NavX™ mapping system. The NO-PARTY is a multi-centre, randomised controlled trial designed to test the hypothesis that catheter ablation of supraventricular tachyarrhythmias guided by the EnSite NavX™ mapping system results in a clinically significant reduction in exposure to ionising radiation compared with conventional catheter ablation. The study will randomise 210 patients undergoing catheter ablation of supraventricular tachyarrhythmias to either a conventional ablation technique or one guided by the EnSite NavX™ mapping system. The primary end-point is the reduction of the radiation dose to the patient. Secondary end-points include procedural success, reduction of the radiation dose to the operator, and a cost-effectiveness analysis. In a subgroup of patients, we will also evaluate the radiobiological effectiveness of dose reduction by assessing acute chromosomal DNA damage in peripheral blood lymphocytes. NO-PARTY will determine whether radiofrequency catheter ablation of supraventricular tachyarrhythmias guided by the EnSite NavX™ mapping system is a suitable and cost-effective approach to achieve a clinically significant reduction in ionising radiation exposure for both patient and operator.

  12. Leaded eyeglasses substantially reduce radiation exposure of the surgeon's eyes during acquisition of typical fluoroscopic views of the hip and pelvis.

    Science.gov (United States)

    Burns, Sean; Thornton, Raymond; Dauer, Lawrence T; Quinn, Brian; Miodownik, Daniel; Hak, David J

    2013-07-17

    Despite recommendations to do so, few orthopaedists wear leaded glasses when performing operative fluoroscopy. Radiation exposure to the ocular lens causes cataracts, and regulatory limits for maximum annual occupational exposure to the eye continue to be revised downward. Using anthropomorphic patient and surgeon phantoms, radiation dose at the surgeon phantom's lens was measured with and without leaded glasses during fluoroscopic acquisition of sixteen common pelvic and hip views. The magnitude of lens dose reduction from leaded glasses was calculated by dividing the unprotected dose by the dose measured behind leaded glasses. On average, the use of leaded glasses reduced radiation to the surgeon phantom's eye by tenfold, a 90% reduction in dose. However, there was widespread variation in the amount of radiation that reached the phantom surgeon's eye among the various radiographic projections we studied. Without leaded glasses, the dose measured at the surgeon's lens varied more than 250-fold among these sixteen different views. In addition to protecting the surgeon's eye from the deleterious effects of radiation, the use of leaded glasses could permit an orthopaedist to perform fluoroscopic views on up to ten times more patients before reaching the annual dose limit of 20 mSv of radiation to the eye recommended by the International Commission on Radiological Protection. Personal safety and adherence to limits of occupational radiation exposure should compel orthopaedists to wear leaded glasses for fluoroscopic procedures if other protective barriers are not in use. Leaded glasses are a powerful tool for reducing the orthopaedic surgeon's lens exposure to radiation during acquisition of common intraoperative fluoroscopic views.

  13. Patient dose assessment in different diagnostic procedures in nuclear medicine

    Energy Technology Data Exchange (ETDEWEB)

    Sena, E de; Bejar, M J; Berenguer, R [Servicio de Radiofisica y Proteccion Radiologica, Salamanca (Spain); Ruano, R; Tamayo, P [Servicio de Medicina Nuclear, Hospital Universitario de Salamanca (Spain)

    2001-03-01

    Effective doses have been estimated for 314 patients under diagnostic procedures in a Nuclear Medicine Department using data reported in ICRP-80 and RIDIC (Radiation Internal Dose Information Center). Data on administered activity, radiopharmaceutical and administration route, age and sex of the patients have been collected. Doses in the most exposed critical organ for every protocol, doses in uterus, doses in fetus versus the stage of pregnancy (in case the female patient was pregnant) and doses for nursing infants have been also estimated. Ga-67 studies give the highest effective doses per protocol followed by cardiac SPECT procedures using Tl-201 chloride. Ga-67 studies also give the highest absorbed doses in uterus. Due to not administering different activities, depending on height and weight of adults, women receive doses about 20% higher than men. This would be a practice to modify in the future in order to optimise doses. (author)

  14. Patient dose assessment in different diagnostic procedures in nuclear medicine

    International Nuclear Information System (INIS)

    Sena, E. de; Bejar, M.J.; Berenguer, R.; Ruano, R.; Tamayo, P.

    2001-01-01

    Effective doses have been estimated for 314 patients under diagnostic procedures in a Nuclear Medicine Department using data reported in ICRP-80 and RIDIC (Radiation Internal Dose Information Center). Data on administered activity, radiopharmaceutical and administration route, age and sex of the patients have been collected. Doses in the most exposed critical organ for every protocol, doses in uterus, doses in fetus versus the stage of pregnancy (in case the female patient was pregnant) and doses for nursing infants have been also estimated. Ga-67 studies give the highest effective doses per protocol followed by cardiac SPECT procedures using Tl-201 chloride. Ga-67 studies also give the highest absorbed doses in uterus. Due to not administering different activities, depending on height and weight of adults, women receive doses about 20% higher than men. This would be a practice to modify in the future in order to optimise doses. (author)

  15. Characterization of a high-elbow, fluoroscopic electronic portal imaging device for portal dosimetry

    International Nuclear Information System (INIS)

    Boer, J.C.J. de; Visser, A.G.

    2000-01-01

    The application of a newly developed fluoroscopic (CCD-camera based) electronic portal imaging device (EPID) in portal dosimetry is investigated. A description of the EPID response to dose is presented in terms of stability, linearity and optical cross-talk inside the mechanical structure. The EPID has a relatively large distance (41 cm on-axis) between the fluorescent screen and the mirror (high-elbow), which results in cross-talk with properties quite different from that of the low-elbow fluoroscopic EPIDs that have been studied in the literature. In contrast with low-elbow systems, the maximum cross-talk is observed for points of the fluorescent screen that have the largest distance to the mirror, which is explained from the geometry of the system. An algorithm to convert the images of the EPID into portal dose images (PDIs) is presented. The correction applied for cross-talk is a position-dependent additive operation on the EPID image pixel values, with a magnitude that depends on a calculated effective field width. Deconvolution with a point spread function, as applied for low-elbow systems, is not required. For a 25 MV beam, EPID PDIs and ionization chamber measurements in the EPID detector plane were obtained behind an anthropomorphic phantom and a homogeneous absorber for various field shapes. The difference in absolute dose between the EPID and ionization chamber measurements, averaged over the four test fields presented in this paper, was 0.1±0.5% (1 SD) over the entire irradiation field, with no deviation larger than 2%. (author)

  16. X-rays individual dose assessment using TLD dosimeters

    International Nuclear Information System (INIS)

    Salas, Carlos

    2008-01-01

    This paper describes the methodology used in Embalse NPP for measuring individual X-ray dose in dentists and radiologists, who work in areas near the plant. Personnel is provided with TLD personal dosimeters for thoracic use, as well as TLD ring dosimeters. This individual X-ray dosimetry is fundamental in order to know the effective energy coming from the radiation field, since the dosimetry factors depend on it. On the other hand, the response of the TLD crystals also depends of the effective energy; this accentuates the problem when assessing the individual dose. The X-ray dosimeter must simultaneously determine the value of the effective energy and the corresponding dose value. The basic principle for determining effective energy is by using at least two different TLD materials covered by filters of different thickness. The TLD materials used have totally energy responses. Therefore, different readouts from each of the crystals are obtained. The ratio between both readouts provides a factor that depends of the effective energy but that is 'independent' from the exposure values irradiated to the dosimeter. The Personal TLD dosimeter currently in use is Bicron-Harshaw. It comprises a carrier model 8807. This carrier contains a card model 2211 which groups two TLD 200 crystals and two TLD 100 crystals. It has internal filters at each side of the TLD 200 crystals. The periodical calibration of these dosimeters consists in the irradiation of some dosimeters with different X-ray energy beams in the National Atomic Energy Commission (CNEA). This dosimeter was used, by the National Regulatory Authority (ARN) in several comparisons, always getting satisfactory results. (author)

  17. Revue of some dosimetry and dose assessment European projects

    International Nuclear Information System (INIS)

    Bolognese-Milsztajn, T.; Frank, D.; Lacoste, V.; Pihet, P.

    2006-01-01

    Full text of publication follows: Within the 5. Framework Programme of the European Commission several project dealing with dosimetry and dose assessment for internal and external exposure have been supported. A revue of the results of some of them is presented in this paper. The EURADOS network which involved 50 dosimetry institutes in EUROPE has coordinated the project DOSIMETRY NETWORK: the main results achieved within this action are the following: - The release on the World Wide Web of the EURADOS Database of Dosimetry Research Facilities; - The realisation of the report 'Harmonization of Individual Monitoring (IM) in Europe'; - The continuation of the intercomparisons programme of environmental radiation monitoring systems; - The realisation of the report Cosmic radiation exposure of aircraft crew. The EVIDOS project aimed at evaluating state of the art dosimetry techniques in representative workplaces of the nuclear industry with complex mixed neutron-photon radiation fields. This paper summarises the main findings from a practical point of view. Conclusions and recommendations will be given concerning characterisation of radiation fields, methods to derive radiation protection quantities and dosimeters results. The IDEA project aimed to improve the assessment of incorporated radionuclides through developments of advanced in-vivo and bioassay monitoring techniques and making use of such enhancements for improvements in routine monitoring. The primary goal was to categorize those new developments regarding their potential and eligibility for the routine monitoring community. The costs of monitoring for internal exposures in the workplace are usually significantly greater than the equivalent costs for external exposures. There is therefore a need to ensure that resources are employed with maximum effectiveness. The EC-funded OMINEX (Optimisation of Monitoring for Internal Exposure) project has developed methods for optimising the design and implementation of

  18. Dose volume assessment of high dose rate 192IR endobronchial implants

    International Nuclear Information System (INIS)

    Cheng, B. Saw; Korb, Leroy J.; Pawlicki, Todd; Wu, Andrew

    1996-01-01

    Purpose: To study the dose distributions of high dose rate (HDR) endobronchial implants using the dose nonuniformity ratio (DNR) and three volumetric irradiation indices. Methods and Materials: Multiple implants were configured by allowing a single HDR 192 Ir source to step through a length of 6 cm along an endobronchial catheter. Dwell times were computed to deliver a dose of 5 Gy to points 1 cm away from the catheter axis. Five sets of source configurations, each with different dwell position spacings from 0.5 to 3.0 cm, were evaluated. Three-dimensional (3D) dose distributions were then generated for each source configuration. Differential and cumulative dose-volume curves were generated to quantify the degree of target volume coverage, dose nonuniformity within the target volume, and irradiation of tissues outside the target volume. Evaluation of the implants were made using the DNR and three volumetric irradiation indices. Results: The observed isodose distributions were not able to satisfy all the dose constraints. The ability to optimally satisfy the dose constraints depended on the choice of dwell position spacing and the specification of the dose constraint points. The DNR and irradiation indices suggest that small dwell position spacing does not result in a more homogeneous dose distribution for the implant. This study supports the existence of a relationship between the dwell position spacing and the distance from the catheter axis to the reference dose or dose constraint points. Better dose homogeneity for an implant can be obtained if the spacing of the dwell positions are about twice the distance from the catheter axis to the reference dose or dose constraint points

  19. C-arm cone beam computed tomography needle path overlay for fluoroscopic guided vertebroplasty.

    Science.gov (United States)

    Tam, Alda L; Mohamed, Ashraf; Pfister, Marcus; Chinndurai, Ponraj; Rohm, Esther; Hall, Andrew F; Wallace, Michael J

    2010-05-01

    Retrospective review. To report our early clinical experience using C-arm cone beam computed tomography (C-arm CBCT) with fluoroscopic overlay for needle guidance during vertebroplasty. C-arm CBCT is advanced three-dimensional (3-D) imaging technology that is currently available on state-of-the-art flat panel based angiography systems. The imaging information provided by C-arm CBCT allows for the acquisition and reconstruction of "CT-like" images in flat panel based angiography/interventional suites. As part of the evolution of this technology, enhancements allowing the overlay of cross-sectional imaging information can now be integrated with real time fluoroscopy. We report our early clinical experience with C-arm CBCT with fluoroscopic overlay for needle guidance during vertebroplasty. This is a retrospective review of 10 consecutive oncology patients who underwent vertebroplasty of 13 vertebral levels using C-arm CBCT with fluoroscopic overlay for needle guidance from November 2007 to December 2008. Procedural data including vertebral level, approach (transpedicular vs. extrapedicular), access (bilateral vs. unilateral) and complications were recorded. Technical success with the overlay technology was assessed based on accuracy which consisted of 4 measured parameters: distance from target to needle tip, distance from planned path to needle tip, distance from midline to needle tip, and distance from the anterior 1/3 of the vertebral body to needle tip. Success within each parameter required that the distance between the needle tip and parameter being evaluated be no more than 5 mm on multiplanar CBCT or fluoroscopy. Imaging data for 12 vertebral levels was available for review. All vertebral levels were treated using unilateral access and 9 levels were treated with an extrapedicular approach. Technical success rates were 92% for both distance from planned path and distance from midline to final needle tip, 100% when distance from needle tip to the anterior 1

  20. Interactive Rapid Dose Assessment Model (IRDAM): reactor-accident assessment methods. Vol.2

    International Nuclear Information System (INIS)

    Poeton, R.W.; Moeller, M.P.; Laughlin, G.J.; Desrosiers, A.E.

    1983-05-01

    As part of the continuing emphasis on emergency preparedness, the US Nuclear Regulatory Commission (NRC) sponsored the development of a rapid dose assessment system by Pacific Northwest Laboratory (PNL). This system, the Interactive Rapid Dose Assessment Model (IRDAM) is a micro-computer based program for rapidly assessing the radiological impact of accidents at nuclear power plants. This document describes the technical bases for IRDAM including methods, models and assumptions used in calculations. IRDAM calculates whole body (5-cm depth) and infant thyroid doses at six fixed downwind distances between 500 and 20,000 meters. Radionuclides considered primarily consist of noble gases and radioiodines. In order to provide a rapid assessment capability consistent with the capacity of the Osborne-1 computer, certain simplifying approximations and assumptions are made. These are described, along with default values (assumptions used in the absence of specific input) in the text of this document. Two companion volumes to this one provide additional information on IRDAM. The user's Guide (NUREG/CR-3012, Volume 1) describes the setup and operation of equipment necessary to run IRDAM. Scenarios for Comparing Dose Assessment Models (NUREG/CR-3012, Volume 3) provides the results of calculations made by IRDAM and other models for specific accident scenarios

  1. Human intruder dose assessment for deep geological disposal

    International Nuclear Information System (INIS)

    Smith, G. M.; Molinero, J.; Delos, A.; Valls, A.; Conesa, A.; Smith, K.; Hjerpe, T.

    2013-07-01

    For near-surface disposal, approaches to assessment of inadvertent human intrusion have been developed through international cooperation within the IAEA's ISAM programme. Other assessments have considered intrusion into deep geological disposal facilities, but comparable international cooperation to develop an approach for deep disposal has not taken place. Accordingly, the BIOPROTA collaboration project presented here (1) examined the technical aspects of why and how deep geological intrusion might occur; (2) considered how and to what degree radiation exposure would arise to the people involved in such intrusion; (3) identified the processes which constrain the uncertainties; and hence (4) developed and documented an approach for evaluation of human intruder doses which addresses the criteria adopted by the IAEA and takes account of other international guidance and human intrusion assessment experience. Models for radiation exposure of the drilling workers and geologists were developed and described together with compilation of relevant input data, taking into account relevant combinations of drilling technique, geological formation and repository material. Consideration has been given also to others who might be exposed to contaminated material left at the site after drilling work has ceased. The models have been designed to be simple and stylised, in accordance with international recommendations. The set of combinations comprises 58 different scenarios which cover a very wide range of human intrusion possibilities via deep drilling. (orig.)

  2. Technique of Peritoneal Catheter Placement under Fluoroscopic Guidance

    International Nuclear Information System (INIS)

    Abdel-Aal, A.K.; Gaddikeri, S.; Saddekni, S.

    2011-01-01

    Peritoneal catheters are mainly used for peritoneal dialysis in patients with end-stage renal disease. Other uses of this catheter include intraperitoneal chemotherapy and gene therapy for ovarian cancer and draining of uncontrolled refractory ascites in patients with liver cirrhosis. Traditionally, surgeons place most of these peritoneal catheters either by laparoscopy or open laparotomy. We detail our percutaneous approach to placing peritoneal catheters using fluoroscopic guidance. We emphasize the use of additional ultrasound guidance, including gray scale and color Doppler ultrasound, to determine the safest puncture site and to guide the initial needle puncture in order to avoid bowel perforation and injury to epigastric artery. We present our experience in placing peritoneal catheters using this technique in 95 patients with various indications. Fluoroscopic guided percutaneous placement of peritoneal catheters is a safe, minimally invasive, and effective alternative to open surgical or laparoscopic placement.

  3. Reevaluation of time spent indoors used for exposure dose assessment

    International Nuclear Information System (INIS)

    Hirose, Katsumi; Fujimoto, Kenzo

    2016-01-01

    A time spent indoors of sixteen hours per day (indoor occupancy factor: 0.67) has been used to assess the radiation dose of residents who spend daily life in the area contaminated due to the nuclear accident in Japan. However, much longer time is considered to be spent indoors for recent modern life. United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has been used an indoor occupancy factor of 0.8 since 1977 and a few reports suggested much higher indoor occupancy factors. Therefore it is important to reevaluate the indoor occupancy factor using current available survey data in Japan, such as 'NHK 2010 National Time Use Survey' and 'Survey on Time Use and Leisure Activities' of Statistics Bureau with certain assumption of time spent indoors in each daily activity. The total time spent indoors in a day is calculated to be 20.2 hours and its indoor occupancy factor is 0.84. Much lower indoor occupancy factors were derived from the survey data by Statistics Bureau for 10 to 14 and 15 to 19 years old groups and farmers who spend most of their time outdoors although present estimated indoor occupancy factor of 0.84 is still lower than those found in some of the relevant reports. A rounded indoor occupancy factor of 0.80 might be the appropriate conservative reference value to be used for the dose estimation of people who live in radioactively contaminated areas and for other relevant purposes of exposure assessment, taken into consideration the present results and values reported in United States Environmental Protection Agency (US EPA) and UNSCEAR. (author)

  4. Assessment of population external irradiation doses with consideration of Rospotrebnadzor bodies equipment for monitoring of photon radiation dose

    Directory of Open Access Journals (Sweden)

    I. P. Stamat

    2016-01-01

    Full Text Available This paper provides review of equipment and methodology for measurement of photon radiation dose; analysis of possible reasons for considerable deviation between the Russian Federation population annual effective external irradiation doses and the relevant average global value. Data on Rospotrebnadzor bodies dosimetry equipment used for measurement of gamma radiation dose are collected and systematized. Over 60 kinds of dosimeters are used for monitoring of population external irradiation doses. Most of dosimeters used in the country have gas-discharge detectors (Geiger-Mueller counters, minor biochemical annunciators, etc. which have higher total values of own background level and of space radiation response than the modern dosimeters with scintillation detectors. This feature of dosimeters is apparently one of most plausible reasons of a bit overstating assessment of population external irradiation doses. The options for specification of population external irradiation doses assessment are: correction of gamma radiation dose measurement results with consideration of dosimeters own background level and space radiation response, introduction of more up-to-date dosimeters with scintillation detectors, etc. The most promising direction of research in verification of population external irradiation doses assessment is account of dosimetry equipment.

  5. Clinical application of percutaneous gastrostomy and gastrojejunostomy under fluoroscopic guidance

    International Nuclear Information System (INIS)

    Zhou Jianping; Wang Zhongmin; Liu Tao; Chen Kemin; Gong Ju; Zheng Yunfeng; Chen Zhijin; Shen Jieyun

    2011-01-01

    Objective: To evaluate the safety and effectiveness of percutaneous gastrostomy (PRG) and gastrojejunostomy (PRGJ) under fluoroscopic guidance, and to discuss its technical manipulation, the indications and contraindications as well as the complications. Methods: During the period from May 2002 to June 2010 in authors' hospital fluoroscopically-guided PRG or PRGJ was carried out in 40 patients. The clinical data were retrospectively analyzed. With Seldinger technique and under fluoroscopic guidance, a 14 F radiopaque gastrostomy or gastrojejunostomy feeding catheter was successfully placed. The indications, operation procedures, clinical success rate, procedure-related complications, and tube indwelling time, etc. were discussed and analyzed. Results: PRG was conducted in 30 patients. The reasons for performing PRG included neurologic disease (n=13), recurrent aspiration pneumonia (n=6), gastroesophageal reflux due to disfunction of gastrointestinal tract (n=3), subtotal gastrectomy (n=2), esophagomediastinal fistula (n=1) and esophageal carcinoma (n=5). PRGJ was carried out in 10 patients. The disorders included bulbar paralysis (n=3), malignant duodenal obstruction (n=4) and previous gastrostomy-related complications (n=3). Two anchors were used in all patients receiving PRG or PRGJ. Clinical success was achieved in all study patients. No procedure-related or severe complications occurred. Minor complications were observed in four patients (10%), which included local soft tissue infection (n=1), severe puncture site pain (n=1), gastrostomy tube dislodgement (n=1) and obstruction of gastrojejunostomy tube (n=1). During the follow-up period, no aggravation of gastroesophageal reflux or aspiration pneumonia was observed in all patients. The tube indwelling time was 115 to 585 days (mean of 150 days) after tube placement. Conclusion: Fluoroscopically-guided percutaneous gastrostomy or gastrojejunostomy is a safe, simple and minimally-invasive technique. This

  6. Internal Dose Conversion Coefficients of Domestic Reference Animal and Plants for Dose Assessment of Non-human Species

    International Nuclear Information System (INIS)

    Keum, Dong Kwon; Jun, In; Lim, Kwang Muk; Choi, Yong Ho

    2009-01-01

    Traditionally, radiation protection has been focused on a radiation exposure of human beings. In the international radiation protection community, one of the recent key issues is to establish the methodology for assessing the radiological impact of an ionizing radiation on non-human species for an environmental protection. To assess the radiological impact to non-human species dose conversion coefficients are essential. This paper describes the methodology to calculate the internal dose conversion coefficient for non-human species and presents calculated internal dose conversion coefficients of 25 radionuclides for 8 domestic reference animal and plants

  7. A rapid method of evaluating fluoroscopic system performance

    International Nuclear Information System (INIS)

    Sprawls, P.

    1989-01-01

    This paper presents a study to develop a method for the rapid evaluation and documentation of fluoroscopic image quality. All objects contained within a conventional contrast-detail test phantom (Leeds TO-10) are displayed in an array format according to their contrast and size. A copy of the display is used as the data collection form and a permanent record of system performance. A fluoroscope is evaluated by viewing the test phantom and marking the visible objects on the display. A line drawn through the objects with minimum visibility in each size group forms a contrast-detail curve for the system. This is compared with a standard or reference line, which is in the display.Deviations in curve position are useful indicators of specific image quality problems, such as excessive noise or blurring. The use of a special object-visibility array format display makes it possible to collect data, analyze the results, and create a record of fluoroscopic performance in less than 2 minutes for each viewing mode

  8. Diffuse and fugitive emission dose assessment on the Hanford Site

    International Nuclear Information System (INIS)

    Davis, W.E.; Schmidt, J.W.; Gleckler, B.P.; Rhoads, K.

    1995-01-01

    On February 3, 1993, the US Department of Energy, Richland Operations Office (RL), received a Compliance Order and Information Request from the Director of the Air and Toxics Division of the US Environmental Protection Agency (EPA), Region 10. The Compliance Order requires RL to (1) evaluate all radionuclide emission points at the Hanford Site to determine which are subject to continuous emission measurement requirements in 40 Code of Federal Regulations (CFR) 61, Subpart H, and (2) continuously measure radionuclide emissions in accordance with 40 CFR 61.93. The Information Request requires RL to provide a written Compliance Plan to meet the requirements of the Compliance Order. The RL Compliance Plan included as one of its milestones the requirement to develop a Federal Facility Compliance Agreement (FFCA). An FFCA was negotiated between RL and the EPA, Region 10, and was entered into on February 7, 1994. One of the milestones was to provide EPA, Region 10, with a copy of the Federal Clean Air Act Title V operating air permit application and Air Emission Inventory (AEI) concurrent with its submission to the Washington State Department of Ecology. The AEI will include an assessment of the diffuse and fugitive emissions from the Hanford Site. This assessment does not identify any diffuse or fugitive emission source that would cause an effective dose equivalent greater than 0.1 mrem/yr

  9. Technology Assessment and Roadmap for the Emergency Radiation Dose Assessment Program

    Energy Technology Data Exchange (ETDEWEB)

    Turteltaub, K W; Hartman-Siantar, C; Easterly, C; Blakely, W

    2005-10-03

    A Joint Interagency Working Group (JIWG) under the auspices of the Department of Homeland Security Office of Research and Development conducted a technology assessment of emergency radiological dose assessment capabilities as part of the overall need for rapid emergency medical response in the event of a radiological terrorist event in the United States. The goal of the evaluation is to identify gaps and recommend general research and development needs to better prepare the Country for mitigating the effects of such an event. Given the capabilities and roles for responding to a radiological event extend across many agencies, a consensus of gaps and suggested development plans was a major goal of this evaluation and road-mapping effort. The working group consisted of experts representing the Departments of Homeland Security, Health and Human Services (Centers for Disease Control and the National Institutes of Health), Food and Drug Administration, Department of Defense and the Department of Energy's National Laboratories (see appendix A for participants). The specific goals of this Technology Assessment and Roadmap were to: (1) Describe the general context for deployment of emergency radiation dose assessment tools following terrorist use of a radiological or nuclear device; (2) Assess current and emerging dose assessment technologies; and (3) Put forward a consensus high-level technology roadmap for interagency research and development in this area. This report provides a summary of the consensus of needs, gaps and recommendations for a research program in the area of radiation dosimetry for early response, followed by a summary of the technologies available and on the near-term horizon. We then present a roadmap for a research program to bring present and emerging near-term technologies to bear on the gaps in radiation dose assessment and triage. Finally we present detailed supporting discussion on the nature of the threats we considered, the status of

  10. Technology Assessment and Roadmap for the Emergency Radiation Dose Assessment Program

    International Nuclear Information System (INIS)

    Turteltaub, K W; Hartman-Siantar, C; Easterly, C; Blakely, W

    2005-01-01

    A Joint Interagency Working Group (JIWG) under the auspices of the Department of Homeland Security Office of Research and Development conducted a technology assessment of emergency radiological dose assessment capabilities as part of the overall need for rapid emergency medical response in the event of a radiological terrorist event in the United States. The goal of the evaluation is to identify gaps and recommend general research and development needs to better prepare the Country for mitigating the effects of such an event. Given the capabilities and roles for responding to a radiological event extend across many agencies, a consensus of gaps and suggested development plans was a major goal of this evaluation and road-mapping effort. The working group consisted of experts representing the Departments of Homeland Security, Health and Human Services (Centers for Disease Control and the National Institutes of Health), Food and Drug Administration, Department of Defense and the Department of Energy's National Laboratories (see appendix A for participants). The specific goals of this Technology Assessment and Roadmap were to: (1) Describe the general context for deployment of emergency radiation dose assessment tools following terrorist use of a radiological or nuclear device; (2) Assess current and emerging dose assessment technologies; and (3) Put forward a consensus high-level technology roadmap for interagency research and development in this area. This report provides a summary of the consensus of needs, gaps and recommendations for a research program in the area of radiation dosimetry for early response, followed by a summary of the technologies available and on the near-term horizon. We then present a roadmap for a research program to bring present and emerging near-term technologies to bear on the gaps in radiation dose assessment and triage. Finally we present detailed supporting discussion on the nature of the threats we considered, the status of technology

  11. Computerized assessment of the measurement of individual doses

    International Nuclear Information System (INIS)

    Kiibus, A.

    1981-06-01

    The department for the measurements of individual doses makes regular dose controls by means of film badges for approximately 14000 individuals. The operation is facilitated by a Honeywell Bull Mini 6 Mod 43 computer. The computer language is COBOL applied to registering of in-data such as delivery of badges, film development, calibration, invoices, recording of individual doses and customers. The print-out consists of customers, badge codes, dosimeter lists, development specifications, dose statements, addresses, bills, dose statistics and the register of individuals. As a consequence of charges the activity is financially self-supporting. (G.B.)

  12. Intravascular ultrasound based dose assessment in endovascular brachytherapy

    International Nuclear Information System (INIS)

    Catalano, Gianpiero; Tamburini, Vittorio; Colombo, Antonio; Nishida, Takahiro; Parisi, Giovanni; Mazzetta, Chiara; Orecchia, Roberto

    2003-01-01

    Background: the role of endovascular brachytherapy in restenosis prevention is well documented. Dose is usually prescribed at a fixed distance from the source axis by angiographic quantification of vessel diameter. Recently, intravascular ultrasound (IVUS) was introduced in dose prescription, allowing a better evaluation of the vessel anatomy. This study retrospectively explores the difference between prescription following angiographic vessel sizing and delivered dose calculated with IVUS. Methods and results: Seventeen lesions were studied with IVUS, identifying on irradiated segment, three sections on which measuring minimal and maximal distance from the centre of IVUS catheter to the adventitia; using dedicated software, corresponding doses were calculated. The dose ranged widely, with maximal and minimal values of 71.6 and 4.9 Gy; furthermore, heterogeneity in dose among different sections was observed. In the central section, the maximal dose was 206% of the one prescribed with the QCA model at 2 mm from the source axis, while the minimal dose was 96%. In proximal and distal sections, respective values were 182, 45, 243, and 122%. Conclusions: Our analysis confirmed the dose inhomogeneity delivered with an angiographic fixed-dose prescription strategy. A dose variation was found along the irradiated segment due to the differences in vessel thickness. IVUS emerged as an important tool in endovascular brachytherapy, especially for irregular-shaped vessels

  13. Models for dose assessments. Modules for various biosphere types

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, U.; Nordlinder, S.; Aggeryd, I. [Studsvik Eco and Safety AB, Nykoeping (Sweden)

    1999-12-01

    The main objective of this study was to provide a basis for illustrations of yearly dose rates to the most exposed individual from hypothetical leakages of radionuclides from a deep bedrock repository for spent nuclear fuel and other radioactive waste. The results of this study will be used in the safety assessment SR 97 and in a study on the design and long-term safety for a repository planned to contain long-lived low and intermediate level waste. The repositories will be designed to isolate the radionuclides for several hundred thousands of years. In the SR 97 study, however, hypothetical scenarios for leakage are postulated. Radionuclides are hence assumed to be transported in the geosphere by groundwater, and probably discharge into the biosphere. This may occur in several types of ecosystems. A number of categories of such ecosystems were identified, and turnover of radionuclides was modelled separately for each ecosystem. Previous studies had focused on generic models for wells, lakes and coastal areas. These models were, in this study, developed further to use site-specific data. In addition, flows of groundwater, containing radionuclides, to agricultural land and peat bogs were considered. All these categories are referred to as modules in this report. The forest ecosystems were not included, due to a general lack of knowledge of biospheric processes in connection with discharge of groundwater in forested areas. Examples of each type of module were run with the assumption of a continuous annual release into the biosphere of 1 Bq for each radionuclide during 10 000 years. The results are presented as ecosystem specific dose conversion factors (EDFs) for each nuclide at the year 10 000, assuming stationary ecosystems and prevailing living conditions and habits. All calculations were performed with uncertainty analyses included. Simplifications and assumptions in the modelling of biospheric processes are discussed. The use of modules may be seen as a step

  14. Models for dose assessments. Modules for various biosphere types

    International Nuclear Information System (INIS)

    Bergstroem, U.; Nordlinder, S.; Aggeryd, I.

    1999-12-01

    The main objective of this study was to provide a basis for illustrations of yearly dose rates to the most exposed individual from hypothetical leakages of radionuclides from a deep bedrock repository for spent nuclear fuel and other radioactive waste. The results of this study will be used in the safety assessment SR 97 and in a study on the design and long-term safety for a repository planned to contain long-lived low and intermediate level waste. The repositories will be designed to isolate the radionuclides for several hundred thousands of years. In the SR 97 study, however, hypothetical scenarios for leakage are postulated. Radionuclides are hence assumed to be transported in the geosphere by groundwater, and probably discharge into the biosphere. This may occur in several types of ecosystems. A number of categories of such ecosystems were identified, and turnover of radionuclides was modelled separately for each ecosystem. Previous studies had focused on generic models for wells, lakes and coastal areas. These models were, in this study, developed further to use site-specific data. In addition, flows of groundwater, containing radionuclides, to agricultural land and peat bogs were considered. All these categories are referred to as modules in this report. The forest ecosystems were not included, due to a general lack of knowledge of biospheric processes in connection with discharge of groundwater in forested areas. Examples of each type of module were run with the assumption of a continuous annual release into the biosphere of 1 Bq for each radionuclide during 10 000 years. The results are presented as ecosystem specific dose conversion factors (EDFs) for each nuclide at the year 10 000, assuming stationary ecosystems and prevailing living conditions and habits. All calculations were performed with uncertainty analyses included. Simplifications and assumptions in the modelling of biospheric processes are discussed. The use of modules may be seen as a step

  15. Dose measurement, its distribution and individual external dose assessments of inhabitants on high background radiation area in China

    Energy Technology Data Exchange (ETDEWEB)

    Koga, Taeko; Morishima, Hiroshige [Kinki Univ., Atomic Energy Research Institute, Osaka (Japan); Tatsumi, Kusuo [Kinki Univ., Life Science Research Institute, Osaka (Japan); Nakai, Sayaka; Sugahara, Tsutomu [Health Research Foundation, Kyoto (Japan); Yuan Yongling [Labor Hygiene Institute of Hunan Prov. (China); Wei Luxin [Laboratory of Industorial Hygiene, Ministry of Health (China)

    2001-01-01

    As a part of the China-Japan cooperative research on the natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external to natural radiation in the high background radiation area (HBRA) of Yangjiang in Guangdong province and in the control area (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by the personal dosimeters, an indirect method was applied to estimate the exposed dose rates from the environmental radiation dose rates measured by survey meters and the occupancy factors of each hamlet. An individual radiation dose roughly correlates with the environmental radiation dose and the life style of the inhabitant. We have analyzed the environmental radiation doses in the hamlets and the variation of the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and the several hamlets of the different level doses in HBRA and Hampizai hamlet in CA. With these parameters, we made estimations of individual dose rates and compared them with those obtained from the direct measurement using dosimeters carried by selected individuals. The results obtained are as follows: (1) The environmental radiation dose rates are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiation. The indoor radiation dose rates were due to the exposure from the natural radioactive nuclides in the building materials and they were about twice higher than the outdoor radiation dose rates. This difference was not observed in CA. (2) The occupancy factor was affected by the age of individuals and the seasons of a year. Indoor occupancy factors were higher for infants and aged individuals than for other age groups. This lead to higher

  16. Dose measurement, its distribution and individual external dose assessments of inhabitants on high background radiation area in China

    International Nuclear Information System (INIS)

    Koga, Taeko; Morishima, Hiroshige; Tatsumi, Kusuo; Nakai, Sayaka; Sugahara, Tsutomu; Yuan Yongling; Wei Luxin

    2001-01-01

    As a part of the China-Japan cooperative research on the natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external to natural radiation in the high background radiation area (HBRA) of Yangjiang in Guangdong province and in the control area (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by the personal dosimeters, an indirect method was applied to estimate the exposed dose rates from the environmental radiation dose rates measured by survey meters and the occupancy factors of each hamlet. An individual radiation dose roughly correlates with the environmental radiation dose and the life style of the inhabitant. We have analyzed the environmental radiation doses in the hamlets and the variation of the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and the several hamlets of the different level doses in HBRA and Hampizai hamlet in CA. With these parameters, we made estimations of individual dose rates and compared them with those obtained from the direct measurement using dosimeters carried by selected individuals. The results obtained are as follows: 1) The environmental radiation dose rates are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiation. The indoor radiation dose rates were due to the exposure from the natural radioactive nuclides in the building materials and they were about twice higher than the outdoor radiation dose rates. This difference was not observed in CA. 2) The occupancy factor was affected by the age of individuals and the seasons of a year. Indoor occupancy factors were higher for infants and aged individuals than for other age groups. This lead to higher

  17. Assessing Doses to Interventional Radiologists Using a Personal Dosimeter Worn Over a Protective Apron

    International Nuclear Information System (INIS)

    Stranden, E.; Widmark, A.; Sekse, T.

    2008-01-01

    Background: Interventional radiologists receive significant radiation doses, and it is important to have simple methods for routine monitoring of their exposure. Purpose: To evaluate the usefulness of a dosimeter worn outside the protective apron for assessments of dose to interventional radiologists. Material and Methods: Assessments of effective dose versus dose to dosimeters worn outside the protective apron were achieved by phantom measurements. Doses outside and under the apron were assessed by phantom measurements and measurements on eight radiologists wearing two routine dosimeters for a 2-month period during ordinary working conditions. Finger doses for the same radiologists were recorded using thermoluminescent dosimeters (TLD; DXT-RAD Extremity dosimeters). Results: Typical values for the ratio between effective dose and dosimeter dose were found to be about 0.02 when the radiologist used a thyroid shield and about 0.03 without. The ratio between the dose to the dosimeter under and outside a protective apron was found to be less than 0.04. There was very good correlation between finger dose and dosimeter dose. Conclusion: A personal dosimeter worn outside a protective apron is a good screening device for dose to the eyes and fingers as well as for effective dose, even though the effective dose is grossly overestimated. Relatively high dose to the fingers and eyes remains undetected by a dosimeter worn under the apron

  18. Assessing Doses to Interventional Radiologists Using a Personal Dosimeter Worn Over a Protective Apron

    Energy Technology Data Exchange (ETDEWEB)

    Stranden, E.; Widmark, A.; Sekse, T. (Buskerud Univ. College, Drammen (Norway))

    2008-05-15

    Background: Interventional radiologists receive significant radiation doses, and it is important to have simple methods for routine monitoring of their exposure. Purpose: To evaluate the usefulness of a dosimeter worn outside the protective apron for assessments of dose to interventional radiologists. Material and Methods: Assessments of effective dose versus dose to dosimeters worn outside the protective apron were achieved by phantom measurements. Doses outside and under the apron were assessed by phantom measurements and measurements on eight radiologists wearing two routine dosimeters for a 2-month period during ordinary working conditions. Finger doses for the same radiologists were recorded using thermoluminescent dosimeters (TLD; DXT-RAD Extremity dosimeters). Results: Typical values for the ratio between effective dose and dosimeter dose were found to be about 0.02 when the radiologist used a thyroid shield and about 0.03 without. The ratio between the dose to the dosimeter under and outside a protective apron was found to be less than 0.04. There was very good correlation between finger dose and dosimeter dose. Conclusion: A personal dosimeter worn outside a protective apron is a good screening device for dose to the eyes and fingers as well as for effective dose, even though the effective dose is grossly overestimated. Relatively high dose to the fingers and eyes remains undetected by a dosimeter worn under the apron

  19. The need for using fluoroscopic guidance to obtain gastric biopsies when in search of Helicobacter pylori with a nonendoscopic method

    International Nuclear Information System (INIS)

    Bender, Greg N.; Mullins, Daniel J.; Makuch, Richard S.

    1999-01-01

    Purpose: Nonendoscopic, fluoroscopic biopsy of the gastric mucosa, following barium examination of the stomach, has gained attention with its ease of performance and cost savings potential over endoscopy. Endoscopic research concerning the efficacy of biopsy sites has revealed an increased sensitivity of antral biopsies over greater curvature biopsies for the detection of Helicobacter pylori. Fluoroscopically guided biopsies of the gastric mucosal are studied to determine whether such a difference between site sensitivity held true. If not, blind biopsy through a nasogastric tube, which traditionally samples only the greater curvature, might prove an even less expensive alternative. Materials and methods: Seventy-two patients underwent nonendoscopic, fluoroscopically guided, mucosal biopsy of both the gastric antrum and the greater curvature of the stomach. Pathologic reports from both sites, using each patient as their own control, are compared to assess site sensitivity in the diagnosis of H. pylori gastritis. Results: The sensitivity for the detection of H. pylori gastritis by antral biopsy is 89% whereas the sensitivity of greater curvature biopsy is 62%. The difference is considered clinically significant at P≤0.05. Conclusions: This study confirms the need for antral biopsies when desiring a nonendoscopic approach to gastric mucosal sampling, in order to obtain a reasonable yield of data in dyspeptic patients with H. pylori gastritis. Blind techniques cannot reliably reach the antrum. Fluoroscopy can, and remains a less expensive alternative to endoscopy

  20. The need for using fluoroscopic guidance to obtain gastric biopsies when in search of Helicobacter pylori with a nonendoscopic method

    Energy Technology Data Exchange (ETDEWEB)

    Bender, Greg N.; Mullins, Daniel J.; Makuch, Richard S

    1999-12-01

    Purpose: Nonendoscopic, fluoroscopic biopsy of the gastric mucosa, following barium examination of the stomach, has gained attention with its ease of performance and cost savings potential over endoscopy. Endoscopic research concerning the efficacy of biopsy sites has revealed an increased sensitivity of antral biopsies over greater curvature biopsies for the detection of Helicobacter pylori. Fluoroscopically guided biopsies of the gastric mucosal are studied to determine whether such a difference between site sensitivity held true. If not, blind biopsy through a nasogastric tube, which traditionally samples only the greater curvature, might prove an even less expensive alternative. Materials and methods: Seventy-two patients underwent nonendoscopic, fluoroscopically guided, mucosal biopsy of both the gastric antrum and the greater curvature of the stomach. Pathologic reports from both sites, using each patient as their own control, are compared to assess site sensitivity in the diagnosis of H. pylori gastritis. Results: The sensitivity for the detection of H. pylori gastritis by antral biopsy is 89% whereas the sensitivity of greater curvature biopsy is 62%. The difference is considered clinically significant at P{<=}0.05. Conclusions: This study confirms the need for antral biopsies when desiring a nonendoscopic approach to gastric mucosal sampling, in order to obtain a reasonable yield of data in dyspeptic patients with H. pylori gastritis. Blind techniques cannot reliably reach the antrum. Fluoroscopy can, and remains a less expensive alternative to endoscopy.

  1. Evaluation of various approaches for assessing dose indicators and patient organ doses resulting from radiotherapy cone-beam CT

    International Nuclear Information System (INIS)

    Rampado, Osvaldo; Giglioli, Francesca Romana; Rossetti, Veronica; Ropolo, Roberto; Fiandra, Christian; Ragona, Riccardo

    2016-01-01

    Purpose: The aim of this study was to evaluate various approaches for assessing patient organ doses resulting from radiotherapy cone-beam CT (CBCT), by the use of thermoluminescent dosimeter (TLD) measurements in anthropomorphic phantoms, a Monte Carlo based dose calculation software, and different dose indicators as presently defined. Methods: Dose evaluations were performed on a CBCT Elekta XVI (Elekta, Crawley, UK) for different protocols and anatomical regions. The first part of the study focuses on using PCXMC software (PCXMC 2.0, STUK, Helsinki, Finland) for calculating organ doses, adapting the input parameters to simulate the exposure geometry, and beam dose distribution in an appropriate way. The calculated doses were compared to readouts of TLDs placed in an anthropomorphic Rando phantom. After this validation, the software was used for analyzing organ dose variability associated with patients’ differences in size and gender. At the same time, various dose indicators were evaluated: kerma area product (KAP), cumulative air-kerma at the isocenter (K_a_i_r), cone-beam dose index, and central cumulative dose. The latter was evaluated in a single phantom and in a stack of three adjacent computed tomography dose index phantoms. Based on the different dose indicators, a set of coefficients was calculated to estimate organ doses for a range of patient morphologies, using their equivalent diameters. Results: Maximum organ doses were about 1 mGy for head and neck and 25 mGy for chest and pelvis protocols. The differences between PCXMC and TLDs doses were generally below 10% for organs within the field of view and approximately 15% for organs at the boundaries of the radiation beam. When considering patient size and gender variability, differences in organ doses up to 40% were observed especially in the pelvic region; for the organs in the thorax, the maximum differences ranged between 20% and 30%. Phantom dose indexes provided better correlation with organ doses

  2. Role of fluoroscopic guided self expandable metallic stents in the management of malignant esophageal strictures

    Directory of Open Access Journals (Sweden)

    Mohamed Shaker

    2016-09-01

    Conclusion: Fluoroscopic guided esophageal stenting is a highly effective and safe method for palliating dysphagia in patients with obstructing esophageal cancer with significant clinical improvement.

  3. Radiation dose assessment of musa acuminata - triploid (AAA)

    International Nuclear Information System (INIS)

    Maravillas, Mart Andrew S.; Locaylocay, Jocelyn R.; Mendoza, Concepcion S.

    2008-01-01

    Bananas are radioactive due to the presence of the radioisotope- 40 K. This imposes a possible health risk to the general public. This study intended to assess the annual equivalent dosages and the annual effective dosage committed by the body. This seeks to benefit the general public, students and researchers, and entrepreneurs. Using atomic absorption spectrophotometry, lakatan banana (Musa acuminata-triploid (AAA), the most purchased variety cultivated in Barangay Adlawon, Cebu City, Philippines, was found to contain 0.53 g of total potassium for every 100 g of its fresh fruit wherein 6.2 x 10 -5 g of which is potassium-40. Based on its 40 K content banana was calculated to have a radioactivity of 16 Bq/100 g. it was found out that the body is exposed to radiation dosages ranging from 2.8 x 10 -3 rem annually by eating 100 g of lakatan bananas everyday. Conversely, it is equivalent to the annual effective dosage of 0.0043 rem; the amount at which the body of an individual is uniformly exposed. However, no or extremely minute health risk was determined by just eating bananas. In fact, to exceed the radiation dose limits set by the International Commission on Radiation Protection, an individual may eat 116 kg of lakatan bananas everyday for a year. Fertilizers may be the major source of the radioisotope - 40 K and assimilated by the plants. (author)

  4. Radiation dose assessment in space missions. The MATROSHKA experiment

    International Nuclear Information System (INIS)

    Reitz, Guenther

    2010-01-01

    The exact determination of radiation dose in space is a demanding and challenging task. Since January 2004, the International Space Station is equipped with a human phantom which is a key part of the MATROSHKA Experiment. The phantom is furnished with thousands of radiation sensors for the measurement of depth dose distribution, which has enabled the organ dose calculation and has demonstrated that personal dosemeter at the body surface overestimates the effective dose during extra-vehicular activity by more than a factor two. The MATROSHKA results serve to benchmark models and have therefore a large impact on the extrapolation of models to outer space. (author)

  5. Fluoroscopy without the grid: a method of reducing the radiation dose

    International Nuclear Information System (INIS)

    Drury, P.; Robinson, A.

    1980-01-01

    The anti-scatter grid has been removed from the fluoroscopic set during the course of over 80 contrast examinations performed routinely during the ordinary workload of a busy paediatric radiology department. This manoeuvre approximatley halves the radiation dose to the patient during both fluoroscopy and radiography. Experience suggests that the degree of loss of contrast consequent on the abandonment of the grid is diagnostically acceptable during many examinations performed on children (of all ages), when balanced against the lower radiation dose received. In addition, an assessment has been made of the contrast improvement factor of the grids in two fluoroscopic sets in common use, using tissue-equivalent phantoms of various thicknesses. Although the contrast was significantly improved by the use of the grid, to a degree dependent on various factors, the relevance of this improvement in clinical radiology depends on exactly what information is being sought. It is recommended that radiologists should use the grid with discretion when performing fluoroscopic examinations on children and that the apparatus for such examinations should have the capability for easy removal and reintroduction of the grid. (author)

  6. Equivalent dose, effective dose and risk assessment from cephalometric radiography to critical organs

    International Nuclear Information System (INIS)

    Kang, Seong Sook; Cho, Bon Hae; Kim, Hyun Ja

    1995-01-01

    In head and neck region, the critical organ and tissue doses were determined, and the risks were estimated from lateral, posteroanterial and basilar cephalometric radiography. For each cephalometric radiography, 31 TLDs were placed in selected sites (18 internal and 13 external sites) in a tissue-equivalent phantom and exposed, then read-out in the TLD reader. The following results were obtained; 1. From lateral cephalometric radiography, the highest effective dose recorded was that delivered to the salivary gland (3.6 μSv) and the next highest dose was that received by the bone marrow (3 μSv). 2. From posteroanterial cephalometric radiography, the highest effective dose recorded was that delivered to the salivary gland (2 μSv) and the next highest dose was that received by the bone marrow (1.8 μSv). 3. From basilar cephalometric radiography, the highest effective dose recorded was that delivered to the thyroid gland (31.4 μSv) and the next highest dose was that received by the salivary gland (13.3 μSv). 4. The probabilities of stochastic effect from lateral, posteroanterial and basilar cephalometric radiography were 0.72 X 10 -6 , 0.49 X 10 -6 and 3.51 X 10 -6 , respectively.

  7. Dose assessment in pediatric computerized tomography; Avaliacao de doses em tomografia computadorizada pediatrica

    Energy Technology Data Exchange (ETDEWEB)

    Vilarinho, Luisa Maria Auredine Lima

    2004-07-01

    The objective of this work was the evaluation of radiation doses in paediatric computed tomography scans, considering the high doses usually involved and the absence of any previous evaluation in Brazil. Dose values were determined for skull and abdomen examinations, for different age ranges, by using the radiographic techniques routinely used in the clinical centers investigated. Measurements were done using pencil shape ionization chambers inserted in polymethylmethacrylate (PMMA) phantoms. These were compact phantoms of different diameters were specially designed and constructed for this work, which simulate different age ranges. Comparison of results with published values showed that doses were lower than the diagnostic reference levels established to adults exams by the European Commission. Nevertheless, doses in paediatric phantoms were higher than those obtained in adult phantoms. The paediatric dose values obtained in Hospitals A and B were lower than the reference level (DRL) adopted by SHIMPTON for different age ranges. In the range 0 - 0.5 year (neonatal), the values of DLP in Hospital B were 94 por cent superior to the DRL For the 10 years old children the values of CTDI{sub w} obtained were inferior in 89 por cent for skull and 83 por cent for abdomen examinations, compared to the values published by SHRIMPTON and WALL. Our measured CTDI{sub w} values were inferior to the values presented for SHRIMPTON and HUDA, for all the age ranges and types of examinations. It was observed that the normalized dose descriptors values in children in the neonatal range were always superior to the values of doses for the adult patient. In abdomen examinations, the difference was approximately 90% for the effective dose (E) and of 57%.for CTDI{sub w} . (author)

  8. Fluoroscopic gating without implanted fiducial markers for lung cancer radiotherapy based on support vector machines

    International Nuclear Information System (INIS)

    Cui Ying; Dy, Jennifer G; Alexander, Brian; Jiang, Steve B

    2008-01-01

    Various problems with the current state-of-the-art techniques for gated radiotherapy have prevented this new treatment modality from being widely implemented in clinical routine. These problems are caused mainly by applying various external respiratory surrogates. There might be large uncertainties in deriving the tumor position from external respiratory surrogates. While tracking implanted fiducial markers has sufficient accuracy, this procedure may not be widely accepted due to the risk of pneumothorax. Previously, we have developed a technique to generate gating signals from fluoroscopic images without implanted fiducial markers using template matching methods (Berbeco et al 2005 Phys. Med. Biol. 50 4481-90, Cui et al 2007b Phys. Med. Biol. 52 741-55). In this note, our main contribution is to provide a totally different new view of the gating problem by recasting it as a classification problem. Then, we solve this classification problem by a well-studied powerful classification method called a support vector machine (SVM). Note that the goal of an automated gating tool is to decide when to turn the beam ON or OFF. We treat ON and OFF as the two classes in our classification problem. We create our labeled training data during the patient setup session by utilizing the reference gating signal, manually determined by a radiation oncologist. We then pre-process these labeled training images and build our SVM prediction model. During treatment delivery, fluoroscopic images are continuously acquired, pre-processed and sent as an input to the SVM. Finally, our SVM model will output the predicted labels as gating signals. We test the proposed technique on five sequences of fluoroscopic images from five lung cancer patients against the reference gating signal as ground truth. We compare the performance of the SVM to our previous template matching method (Cui et al 2007b Phys. Med. Biol. 52 741-55). We find that the SVM is slightly more accurate on average (1-3%) than

  9. The choice of food consumption rates for radiation dose assessments

    International Nuclear Information System (INIS)

    Simmonds, J.R.; Webb, G.A.M.

    1981-01-01

    The practical problem in estimating radiation doses due to radioactive contamination of food is the choice of the appropriate food intakes. To ensure compliance or to compare with dose equivalent limits, higher than average intake rates appropriate to critical groups should be used. However for realistic estimates of health detriment in the whole exposed population, average intake rates are more appropriate. (U.K.)

  10. The Northern Marshall Islands radiological survey: Data and dose assessments

    International Nuclear Information System (INIS)

    Robison, W.L.; Noshkin, V.E.; Conrado, C.L.

    1997-01-01

    Fallout from atmospheric nuclear tests, especially from those conducted at the Pacific Proving Grounds between 1946 and 1958, contaminated areas of the Northern Marshall Islands. A radiological survey at some Northern Marshall Islands was conducted from September through November 1978 to evaluate the extent of residual radioactive contamination. The atolls included in the Northern Marshall Islands Radiological Survey (NMIRS) were Likiep, Ailuk, Utirik, Wotho, Ujelang, Taka, Rongelap, Rongerik, Bikar, Ailinginae, and Mejit and Jemo Islands. The original test sites, Bikini and Enewetak Atolls, were also visited on the survey. An aerial survey was conducted to determine the external gamma exposure rate. Terrestrial (soil, food crops, animals, and native vegetation), cistern and well water samples, and marine (sediment, seawater, fish and clams) samples were collected to evaluate radionuclide concentrations in the atoll environment. Samples were processed and analyzed for 137 Cs, 90 Sr, 239+240 Pu and 241 Am. The dose from the ingestion pathway was calculated using the radionuclide concentration data and a diet model for local food, marine, and water consumption. The ingestion pathway contributes 70% to 90% of the estimated dose. Approximately 95% of the dose is from 137 Cs accounts for about 10% to 30% of the dose. 239+240 Pu and 241 Am are the major contributors to dose via the inhalation pathway; however, inhalation accounts for only about 1% of the total estimated dose, based on surface soil levels and resuspension studies. All doses are computed for concentrations decay corrected to 1996. The maximum annual effective dose from manmade radionuclides at these atolls ranges from .02 mSv y -1 . The background dose in the Marshall Islands is estimated to be 2.4 mSv y -1 to 4.5 mSv y -1 . The 50-y integral dose ranges from 0.5 to 65 mSv. 35 refs., 2 figs., 9 tabs

  11. Common fluoroscopic studies in radiology : conduct and analysis method

    International Nuclear Information System (INIS)

    Valverde Sanchez, Allan

    2011-01-01

    A countless number of radiological procedures, that have involved the use of fluoroscopy and contrast media of different indole, have been carried out in all radiology services and medical images of Costa Rica for the diagnosis of diseases or conditions, in both adults and in children. Fluoroscopic studies, often called special or contrast studies, have had particular conditions for its realization. Some from the medical point of view: adequate training in the technical and cognitive development when evaluating the images to not miss important details. Other by the patient: adequate preparation to achieve the best images for optimal diagnosis. For example, adequate bowel preparation is essential for a barium enema, to cooperation by the patient to meet specific indications that the physician dictates when swallowing postures or just when you are prompted. Criteria have been met and unified for contrast studies in different hospitals and clinics. The indications, contra, method, technique of procedure, points to remember, number of images or projections minimum required in the interpretation of contrast studies, as well as a report template of standard and ideal study are presented in a simple, systematic and logical. The manual is intended for residents and attending physicians specialists in radiology and medical imaging including contrast studies more common. Spaces are promoted with current technology studies to set aside more complicated and less sophisticated as have been the fluoroscopic studies; however, in the national reality, access to computerized tomography and magnetic resonance imaging is not as easy. Radiological studies with fluoroscopy performed by trained staff led the treating physician to make sound decisions based on studies relatively simple and easy to do. The tests with the use of fluoroscopic have been named: the esophagogram, gastroduodenal series, gastro intestinal transit, the hysterosalpingography, the cystography and the

  12. Fluoroscopic guidance of retrograde exchange of ureteral stents in women.

    Science.gov (United States)

    Chang, Ruey-Sheng; Liang, Huei-Lung; Huang, Jer-Shyung; Wang, Po-Chin; Chen, Matt Chiung-Yu; Lai, Ping-Hong; Pan, Huay-Ben

    2008-06-01

    The purpose of this study was to review our experience with fluoroscopically guided retrograde exchange of ureteral stents in women. During a 48-month period, 28 women (age range, 38-76 years) were referred to our department for retrograde exchange of a ureteral stent. The causes of urinary obstruction were tumor compression in 26 patients and benign fibrotic stricture in two patients. A large-diameter snare catheter (25-mm single loop or 18- to 35-mm triple loop) or a foreign body retrieval forceps (opening width, 11.3 mm) was used to grasp the bladder end of the stent under fluoroscopic guidance. The technique entailed replacement of a patent or occluded ureteral stent with a 0.035- or 0.018-inch guidewire with or without the aid of advancement of an angiographic sheath. A total of 54 ureteral stents were exchanged with a snare catheter in 42 cases or a forceps in 12 cases. One stent misplaced too far up the ureter was replaced successfully through antegrade percutaneous nephrostomy. Ten occluded stents, including one single-J stent, were managed with a 0.018-inch guidewire in three cases, advancement of an angiographic sheath over the occluded stent into the ureter in five cases, and recannulation of the ureteral orifice with a guidewire in two cases. No complications of massive hemorrhage, ureter perforation, or infection were encountered. With proper selection of a snare or forceps catheter, retrograde exchange of ureteral stents in women can be easily performed under fluoroscopic guidance with high technical success and a low complication rate.

  13. Model for assessing alpha doses for a Reference Japanese Man

    International Nuclear Information System (INIS)

    Kawamura, Hisao

    1993-01-01

    In view of the development of the nuclear fuel cycle in this country, it is urgently important to establish dose assessment models and related human and environmental parameters for long-lived radionuclides. In the current program, intake and body content of actinides (Pu, Th, U) and related alpha-emitting nuclides (Ra and daughters) have been studied as well as physiological aspects of Reference Japanese Man as the basic model of man for dosimetry. The ultimate object is to examine applicability of the existing models particularly recommended by the ICRP for workers to members of the public. The result of an interlaboratory intercomparison of 239 Pu + 240 Pu determination including our result was published. Alpha-spectrometric determinations of 226 Ra in bone yielded repesentative bone concentration level in Tokyo and Ra-Ca O.R. (bone-diet) which appear consistent with the literature value for Sapporo and Kyoto by Ohno using a Rn emanation method. Specific effective energies for alpha radiation from 226 Ra and daughters were calculated using the ICRP dosimetric model for bone incorporating masses of source and target organs of Reference Japanese Man. Reference Japanese data including the adult, adolescent, child and infant of both sexes was extensively and intensively studied by Tanaka as part of the activities of the ICRP Task Group on Reference Man Revision. Normal data for the physical measurements, mass and dimension of internal organs and body surfaces and some of the body composition were analysed viewing the nutritional data in the Japanese population. Some of the above works are to be continued. (author)

  14. Radiation Dose-Response Relationships and Risk Assessment

    International Nuclear Information System (INIS)

    Strom, Daniel J.

    2005-01-01

    The notion of a dose-response relationship was probably invented shortly after the discovery of poisons, the invention of alcoholic beverages, and the bringing of fire into a confined space in the forgotten depths of ancient prehistory. The amount of poison or medicine ingested can easily be observed to affect the behavior, health, or sickness outcome. Threshold effects, such as death, could be easily understood for intoxicants, medicine, and poisons. As Paracelsus (1493-1541), the 'father' of modern toxicology said, 'It is the dose that makes the poison.' Perhaps less obvious is the fact that implicit in such dose-response relationships is also the notion of dose rate. Usually, the dose is administered fairly acutely, in a single injection, pill, or swallow; a few puffs on a pipe; or a meal of eating or drinking. The same amount of intoxicants, medicine, or poisons administered over a week or month might have little or no observable effect. Thus, before the discovery of ionizing radiation in the late 19th century, toxicology ('the science of poisons') and pharmacology had deeply ingrained notions of dose-response relationships. This chapter demonstrates that the notion of a dose-response relationship for ionizing radiation is hopelessly simplistic from a scientific standpoint. While useful from a policy or regulatory standpoint, dose-response relationships cannot possibly convey enough information to describe the problem from a quantitative view of radiation biology, nor can they address societal values. Three sections of this chapter address the concepts, observations, and theories that contribute to the scientific input to the practice of managing risks from exposure to ionizing radiation. The presentation begins with irradiation regimes, followed by responses to high and low doses of ionizing radiation, and a discussion of how all of this can inform radiation risk management. The knowledge that is really needed for prediction of individual risk is presented

  15. Radiation dose assessment of ACP hot cell in accident

    International Nuclear Information System (INIS)

    Kook, D. H.; Jeong, W. M.; Koo, J. H.; Jeo, I. J.; Lee, E. P.; Ryu, K. S.

    2003-01-01

    The Advanced spent fuel Condition in Process(ACP) is under development for the effective management of spent fuel which had been generated in nuclear plants. The ACP needs a hot cell where most operations will be performed. To give priority to the environments safety, radiation doses evaluations for the radioactive nuclides in accident cases were preliminarily performed with the meteorological data around facility site. Fire accident prevails over several accidnets. Internal Dose and External Dose evaluation according to short dispersion data for that case show a safe margin for regulation limits and SAR limit of IMEF where this facility will be constructed

  16. Study, assessment of radioactive dose on China's population

    Energy Technology Data Exchange (ETDEWEB)

    Ziqiang, P.

    1984-05-10

    The national population dose is defined as the radioactive dose from both natural and artificial sources which is received by the entire Chinese population. The necessity and prospects for developing ways to assess China's national population dose and some noteworthy problems in this area are described.

  17. Specific gamma-ray dose constants for nuclides important to dosimetry and radiological assessment

    International Nuclear Information System (INIS)

    Unger, L.M.; Trubey, D.K.

    1982-05-01

    Tables of specific gamma-ray dose constants (the unshielded gamma-ray dose equivalent rate at 1 m from a point source) have been computed for approximately 500 nuclides important to dosimetry and radiological assessment. The half life, the mean attenuation coefficient, and thickness for a lead shield providing 95% dose equivalent attenuation are also listed

  18. Dose assessment of an accidental exposure at IPNS

    International Nuclear Information System (INIS)

    Torres, M.M.C.

    1996-01-01

    Seven different methods were used to estimate the dose rate to a female worker who was accidentally exposed in the neutron PHOENIX beamline at the IPNS. Theoretical and measured entrance dose rates ranged from 550 mrem/min to 2,850 mrem/min. Theoretical estimates were based on a Monte Carlo simulation of a spectrum provided by IPNS (Crawford Spectrum). Dose measurements were made with TLDs on phantoms and with ionization chambers in a water phantom. Estimates of the whole body total effective dose equivalent (TEDE) rate ranged from 5.2 mrem/min to 840 mrem/min. Assumed and measured quality factors ranged from 2.6 to 11.8. Cytogenic analyses of blood samples detected no positive exposure. The recommended TEDE rate was 158 mrem/min. The TEDE was 750 mrem

  19. Dose assessment of an accidental exposure at the IPNS

    International Nuclear Information System (INIS)

    Campos Torres, M.M.

    1995-02-01

    Seven different methods were used to estimate the dose rate to a female worker who was accidentally exposed in the neutron PHOENIX beamline at the IPNS. Theoretical and measured entrance dose ranged from 550 mrem/min to 2850 mrem/min. Theoretical estimates were based on a Monte Carlo simulation of a spectrum provided by IPNS (Crawford Spectrum). Dose measurements were made with TLDs on phantoms and with ionization chambers in a water phantom. Estimates of the whole body total effective dose equivalent (TEDE) rate ranged from 5.2 mrem/min to 840 mrem/min. Assumed and measured quality factors ranged from 2.6 to 11.8. Cytogenetic analyses of blood samples detected no positive exposure. The recommended TEDE rate was 158 mrem/min. The TEDE was 750 mrem

  20. The Northern Marshall Islands Radiological Survey: data and dose assessments.

    Science.gov (United States)

    Robison, W L; Noshkin, V E; Conrado, C L; Eagle, R J; Brunk, J L; Jokela, T A; Mount, M E; Phillips, W A; Stoker, A C; Stuart, M L; Wong, K M

    1997-07-01

    Fallout from atmospheric nuclear tests, especially from those conducted at the Pacific Proving Grounds between 1946 and 1958, contaminated areas of the Northern Marshall Islands. A radiological survey at some Northern Marshall Islands was conducted from September through November 1978 to evaluate the extent of residual radioactive contamination. The atolls included in the Northern Marshall Islands Radiological Survey (NMIRS) were Likiep, Ailuk, Utirik, Wotho, Ujelang, Taka, Rongelap, Rongerik, Bikar, Ailinginae, and Mejit and Jemo Islands. The original test sites, Bikini and Enewetak Atolls, were also visited on the survey. An aerial survey was conducted to determine the external gamma exposure rate. Terrestrial (soil, food crops, animals, and native vegetation), cistern and well water samples, and marine (sediment, seawater, fish and clams) samples were collected to evaluate radionuclide concentrations in the atoll environment. Samples were processed and analyzed for 137Cs, 90Sr, 239+240Pu and 241Am. The dose from the ingestion pathway was calculated using the radionuclide concentration data and a diet model for local food, marine, and water consumption. The ingestion pathway contributes 70% to 90% of the estimated dose. Approximately 95% of the dose is from 137Cs. 90Sr is the second most significant radionuclide via ingestion. External gamma exposure from 137Cs accounts for about 10% to 30% of the dose. 239+240Pu and 241Am are the major contributors to dose via the inhalation pathway; however, inhalation accounts for only about 1% of the total estimated dose, based on surface soil levels and resuspension studies. All doses are computed for concentrations decay corrected to 1996. The maximum annual effective dose from manmade radionuclides at these atolls ranges from .02 mSv y(-1) to 2.1 mSv y(-1). The background dose in the Marshall Islands is estimated to be 2.4 mSv y(-1). The combined dose from both background and bomb related radionuclides ranges from slightly

  1. Blood compounds irradiation process: assessment of absorbed dose using Fricke and Thermoluminescent dosimetric systems

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Gabriela de Amorim; Squair, Peterson Lima; Pinto, Fausto Carvalho; Belo, Luiz Claudio Meira; Grossi, Pablo Andrade [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN-CNEN/MG), Belo Horizonte, MG (Brazil)], e-mail: gas@cdtn.br, e-mail: pls@cdtn.br, e-mail: fcp@cdtn.br, e-mail: lcmb@cdtn.br, e-mail: pabloag@cdtn.br

    2009-07-01

    The assessment of gamma absorbed doses in irradiation facilities allows the quality assurance and control of the irradiation process. The liability of dose measurements is assign to the metrological procedures adopted including the uncertainty evaluation. Fricke and TLD 800 dosimetric systems were used to measure absorbed dose in the blood compounds using the methodology presented in this paper. The measured absorbed doses were used for evaluating the effectiveness of the irradiation procedure and the gamma dose absorption inside the irradiation room of a gamma irradiation facility. The radiation eliminates the functional and proliferative capacities of donor T-lymphocytes, preventing Transfusion associated graft-versus-host disease (TA-GVHD), a possible complication of blood transfusions. The results show the applicability of such dosimetric systems in quality assurance programs, assessment of absorbed doses in blood compounds and dose uniformity assign to the blood compounds irradiation process by dose measurements in a range between 25 Gy and 100 Gy. (author)

  2. Blood compounds irradiation process: assessment of absorbed dose using Fricke and Thermoluminescent dosimetric systems

    International Nuclear Information System (INIS)

    Soares, Gabriela de Amorim; Squair, Peterson Lima; Pinto, Fausto Carvalho; Belo, Luiz Claudio Meira; Grossi, Pablo Andrade

    2009-01-01

    The assessment of gamma absorbed doses in irradiation facilities allows the quality assurance and control of the irradiation process. The liability of dose measurements is assign to the metrological procedures adopted including the uncertainty evaluation. Fricke and TLD 800 dosimetric systems were used to measure absorbed dose in the blood compounds using the methodology presented in this paper. The measured absorbed doses were used for evaluating the effectiveness of the irradiation procedure and the gamma dose absorption inside the irradiation room of a gamma irradiation facility. The radiation eliminates the functional and proliferative capacities of donor T-lymphocytes, preventing Transfusion associated graft-versus-host disease (TA-GVHD), a possible complication of blood transfusions. The results show the applicability of such dosimetric systems in quality assurance programs, assessment of absorbed doses in blood compounds and dose uniformity assign to the blood compounds irradiation process by dose measurements in a range between 25 Gy and 100 Gy. (author)

  3. Assessment of genetically significant doses to the Sofia population from natural gamma background

    International Nuclear Information System (INIS)

    Vasilev, G.; Khristova, M.

    1977-01-01

    Genetically significant dose to the population of Sofia city was assessed within a program covering larger urban communities in the country. Measurements were made of gamma background exposure rates in the gonadal region. Gonad doses were estimated using a screening factor of 0.73. Based on statistical data for total number of inhabitants and number of people of reproductive age, and on the mean annual gonad doses derived, calculations were made of genetically significant dose to the Sofia population. Base-line data were thus provided for an assessment of extra radiation dose resulting from occupational radiation exposure. (author)

  4. Assessment of patient radiation doses during routine diagnostic radiography examinations

    International Nuclear Information System (INIS)

    Adam, Asim Karam Aldden Adam

    2015-11-01

    Medical applications of radiation represent the largest source of exposure to general population. Accounting for 3.0 mSv against an estimated 2.4 mSv from a natural back ground in United States. The association of ionizing radiation an cancer risk is assumed to be continuos and graded over the entire range of exposure, The objective of this study is to evaluate the patient radiation doses in radiology departments in Khartoum state. A total of 840 patients ? during two in the following hospitals Khartoum Teaching Hospital (260 patients), Fedail specialized hospital ( 261 patients). National Ribat University hospital ( 189 patients) and Engaz hospital (130 patients). Patient doses were measured for 9 procedures. The Entrance surface Air Kerma (ESAK) was quantified using x-ray unit output by Unifiers xi dose rate meter( Un fore inc. Billdal. Sweden) and patient exposure parameters. The mean patient age. Weight and Body Mass index (BMI) were 42.6 year 58/4 kg and 212 kg/m respectively. The mean patient doses, kv and MAS and E.q was 0.35 mGy per procedures 59.9 volt 19.8 Ampere per second 0.32 Sv . Patient doses were comparable with previous studies. Patient radiation doses showed considerable difference between hospitals due to x- ray systems exposure settings and patient weight. Patient are exposed to unnecessary radiation.(Author)

  5. Radiation injury of the skin following diagnostic and interventional fluoroscopic procedures

    International Nuclear Information System (INIS)

    Koenig, T.R.; Wagner, L.K.; Mettler, F.A.

    2001-01-01

    Many radiation injuries to the skin, resulting from diagnostic and interventional fluoroscopic procedures, have been reported in recent years. In some cases skin damage was severe and debilitating. We analyzed 72 reports of skin injuries for progression and location of injury, type and number of procedures, and contributing patient and operator factors. Most cases (46) were related to coronary angiography and percutaneous transluminal coronary angioplasty (PTCA). A smaller number was documented after cardiac radiofrequency catheter ablation (12), transjugular intrahepatic portosystemic shunt (TIPS) placement (7), neuroradiological interventions (3) and other procedures (4). Important factors leading to skin injuries were long exposure times over the same skin area, use of high dose rates, irradiation through thick tissue masses, hypersensitivity to radiation, and positioning of arms or breasts into the radiation entrance beam. Physicians were frequently unaware of the high radiation doses involved and did not recognize the injuries as radiation induced. Based on these findings, recommendations to reduce dose and improve patient care are provided. (author)

  6. Assessment of prospective foodchain doses from radioactive discharges from BNFL Sellafield

    International Nuclear Information System (INIS)

    Ould-Dada, Z.; Tucker, S.; Webbe-Wood, D.; Mondon, K.; Hunt, J.

    2002-01-01

    This paper presents the method used by the UK Food Standards Agency (FSA) to assess the potential impact of proposed radioactive discharges from the Sellafield nuclear site on food and determine their acceptability. It explains aspects of a cautious method that has been adopted to reflect the UK government policy and uncertainties related to people's habits with regard to food production and consumption. Two types of ingestion doses are considered in this method: 'possible' and 'probable' doses. The method is specifically applied to Sellafield discharge limits and calculated possible and probable ingestion doses are presented and discussed. Estimated critical group ingestion doses are below the dose limit and constraint set for members of the public. The method may be subject to future amendments to take account of changes in government policy and the outcome of a recent Consultative Exercise on Dose Assessments carried out by FSA. Uncertainties inherent in dose assessments are discussed and quantified wherever possible

  7. Accurate assessment of the distortions produced by the transit dose in HDR brachytherapy

    International Nuclear Information System (INIS)

    Nani, E.K.; Kyere, A.W.K.; Tetteh, K.

    2001-01-01

    Current polynomial methods used in the modelling of the dose distributions in HDR brachytherapy have been reformulated to improve accuracy. An example is provided to show the effects of the transit dose on the output. The transit dose, which is neglected by current computer software for calculating doses, can result in significant dosimetric errors. These additional unrecognised doses imply over-dosing and distortions in the dose distributions within the irradiated volume. Assessment of dose to critical and radiosensitive organs is therefore inaccurate. These could increase late tissue complications as predicted by the Linear Quadratic Model. Our model works very well for straight catheters and is highly recommended for the evaluation of the transit dose around such catheters. (author)

  8. Assessment of patients' skin dose during interventional cardiology procedures

    International Nuclear Information System (INIS)

    Tsapaki, V.; Vardalaki, E.; Kottou, S.; Molfetas, M.; Neofotistou, V.

    2002-01-01

    During the last 30 years the use of Interventional Cardiology (IC) procedures has increased significantly, mainly due to the benefits and advantages of the method that offers more accurate diagnosis and treatment along with less complications and hospitalization. However, IC procedures are based on the use of x-ray radiation, mostly localized at certain areas of patient's body and for extended periods of time. Consequently, patient may receive high radiation dose and deterministic effects, such as erythema, epilation or even dermal necrosis may be observed. Therefore, the need for reducing radiation dose is highly important. In order to achieve this, good knowledge of the dose levels delivered to the patient during IC procedures is essential since radiation effects are known to increase with dose. It is of great interest to know the point where the maximum skin dose (MSD) is noted since individual sensitivity may vary. MSDs greater than 1 Gy should be recorded. Patient dosimetry during IC procedures is a complex task since these type of procedures depend on various factors, such as complexity and severity of case, different specifications of x-ray equipment and patient's physical characteristics. Moreover, cardiologist's experience plays an important role. For these reasons, Food and Drug Administration (FDA), the International Commission on Radiological Protection (ICRP) as well as the World Health Organization (WHO), have published documents on radiation safety and ways to reduce skin injuries during IC procedures. Various methods have been proposed for measuring MSD such as the use of slow radiotherapy films, thermoluminescent detectors (TLD), scintillation detectors, Dose-Area Product (DAP) meter, as well as a combination of DAP and air kerma. A literature review on MSDs measured during IC procedures showed that doses ranged from 300 to 43000 mGy

  9. Trial manufacture of round mask for TV fluoroscopic unit

    International Nuclear Information System (INIS)

    Matsuoka, Shoji; Matsumoto, Yukio

    1977-01-01

    Demands for revision of existing medical law were described together with an introduction of TV fluoroscopic unit. Round mask, which does not always press out the bottom face of used x-ray beam from the effective primary fluorescent face of photomultiplier inspite of shifting of a spot in time of TV fluoroscopy, was manufactured for trial, and it was furnished with already established fluoroscopic stand. It is used in daily examination without any trouble. Round mask was divided into two parts, and opened upward and downward quickly by lod motor in time of photographing. Multiple iris was operated in order to fit to film size, and round mask was closed at the same time of the finishment of photographing and fluoroscopy was performed again. Item 3 of Para 2 of Art 30 of the existing medical low states that it is good not to press out, the distance between x-ray focus and fluorescent screen, and used x-ray beam from fluorescent screen. However, a regulation, which states that x-ray beam should not be pressed out from effective primary fluorescent face in x-ray fluoroscopy using photomultiplier, must be added. Improvement of the existing unit is expected, and decrease of unnecessary exposure even in small amount is proposed. (Tsunoda, M.)

  10. Diagnosis of cardiovascular diseases by digital fluoroscopic angiography

    International Nuclear Information System (INIS)

    Takahashi, Mutsumasa; Hirota, Yoshihisa; Tsuchigame, Naotoshi

    1982-01-01

    Digital fluoroscopic angiography (DFA) is a recently developed angiocardiographic technique, which consists of digitization and real-time subtraction of X-ray transmission data from an image intensifier and television fluoroscopic system. A prototype unit based on this principle was developed and installed at our hospital and initial clinical trial has been performed. Fifty-three examinations were performed on 49 patients with various cardiovascular conditions. DFA was useful in demonstration of intracardiac shunt, and valvular diseases secondary to congenital heart diseases. In ischemic heart diseases, DFA noninvasively demonstrated the heart wall motion, making it possible to evaluate dyskinesis, akinesis and ventricular aneurysm. DFA was also valuable in visualizing disproportionate enlargement of cardiac chambers, stasis, and frequently regurgitation of contrast media in valvular heart diseases. Abnormal mediastinal enlargement and aortic aneurysm were differentiated from other conditions to good advantage. DFA will be used more widely in the above conditions because of non-invasive and simple procedures. Future effort should be directed towards improvement of spatial resolution and development of new algorithm for hemodynamic evaluation. (author)

  11. Cryo-balloon catheter localization in fluoroscopic images

    Science.gov (United States)

    Kurzendorfer, Tanja; Brost, Alexander; Jakob, Carolin; Mewes, Philip W.; Bourier, Felix; Koch, Martin; Kurzidim, Klaus; Hornegger, Joachim; Strobel, Norbert

    2013-03-01

    Minimally invasive catheter ablation has become the preferred treatment option for atrial fibrillation. Although the standard ablation procedure involves ablation points set by radio-frequency catheters, cryo-balloon catheters have even been reported to be more advantageous in certain cases. As electro-anatomical mapping systems do not support cryo-balloon ablation procedures, X-ray guidance is needed. However, current methods to provide support for cryo-balloon catheters in fluoroscopically guided ablation procedures rely heavily on manual user interaction. To improve this, we propose a first method for automatic cryo-balloon catheter localization in fluoroscopic images based on a blob detection algorithm. Our method is evaluated on 24 clinical images from 17 patients. The method successfully detected the cryoballoon in 22 out of 24 images, yielding a success rate of 91.6 %. The successful localization achieved an accuracy of 1.00 mm +/- 0.44 mm. Even though our methods currently fails in 8.4 % of the images available, it still offers a significant improvement over manual methods. Furthermore, detecting a landmark point along the cryo-balloon catheter can be a very important step for additional post-processing operations.

  12. Epistemological problems in assessing cancer risks at low radiation doses

    International Nuclear Information System (INIS)

    Walinder, G.

    1987-01-01

    Historically, biology has not been subjected to any epistemological analysis as has been the case with mathematics and physics. Our knowledge of the effects in biological systems of various stimuli proves to be dualistic in a complementary (although not mutually exclusive) way, which bears resemblance to the knowledge of phenomena in quantum physics. The dualistic limbs of biological knowledge are the action of stimuli and the response of the exposed, biological system. With regard to radiogenic cancer, this corresponds to the action of the ionizations and the response of the exposed mammal to that action, respectively. The following conclusions can be drawn from the present analysis: Predictions as to radiogenic cancer seem often if not always to have neglected the response variability (variations in radiosensitivity) in individuals or among individuals in populations, i.e. the predictions have been based exclusively on radiation doses and exposure conditions. The exposed individual or population, however, must be considered an open statistical system, i.e. a system in which predictions as to the effect of an agent are only conditionally possible. The knowledge is inverse to the size of the dose or concentration of the active agent. On epistemological grounds, we can not gain knowledge about the carcinogenic capacity of very low (non-dominant) radiation doses. Based on the same principle, we can not predict cancer risks at very low (non-dominant) radiation doses merely on the basis of models, or otherwise interpolated or extrapolated high-dose effects, observed under special exposure conditions

  13. Radiation dose from Chernobyl forests: assessment using the 'forestpath' model

    International Nuclear Information System (INIS)

    Schell, W.R.; Linkov, I.; Belinkaia, E.; Rimkevich, V.; Zmushko, Yu.; Lutsko, A.; Fifield, F.W.; Flowers, A.G.; Wells, G.

    1996-01-01

    Contaminated forests can contribute significantly to human radiation dose for a few decades after initial contamination. Exposure occurs through harvesting the trees, manufacture and use of forest products for construction materials and paper production, and the consumption of food harvested from forests. Certain groups of the population, such as wild animal hunters and harvesters of berries, herbs and mushrooms, can have particularly large intakes of radionuclides from natural food products. Forestry workers have been found to receive radiation doses several times higher than other groups in the same area. The generic radionuclide cycling model 'forestpath' is being applied to evaluate the human radiation dose and risks to population groups resulting from living and working near the contaminated forests. The model enables calculations to be made to predict the internal and external radiation doses at specific times following the accident. The model can be easily adjusted for dose calculations from other contamination scenarios (such as radionuclide deposition at a low and constant rate as well as complex deposition patterns). Experimental data collected in the forests of Southern Belarus are presented. These data, together with the results of epidemiological studies, are used for model calibration and validation

  14. Pan-oral dose assessment: a comparative report of methodologies

    International Nuclear Information System (INIS)

    Shafford, J.; Pryor, M.; Hollaway, P.; Peet, D.; Oduko, J.

    2015-01-01

    National guidance from the Institute of Physics and Engineering in Medicine (IPEM Report 91) currently recommends that the patient dose for a pan-oral X-ray unit is measured as dose area product (DAP) replacing dose width product described in earlier guidance. An investigation identifying different methods available to carry out this measurement has been undertaken and errors in the methodologies analysed. It has been shown that there may be up to a 30 % variation in DAP measurement between methods. This paper recommends that where possible a DAP meter is used to measure the dose-area product from a pan-oral X-ray unit to give a direct DAP measurement. However, by using a solid-state dose measurement and film/ruler to calculate DAP the authors have established a conversion factor of 1.4. It is strongly recommended that wherever a DAP value is quoted the methodology used to obtain that value is also reported. (authors)

  15. Dose assessment according to changes in algorithm in cardiac CT

    Science.gov (United States)

    Jang, H. C.; Cho, J. H.; Lee, H. K.; Hong, I. S.; Cho, M. S.; Park, C. S.; Lee, S. Y.; Dong, K. R.; Goo, E. H.; Chung, W. K.; Ryu, Y. H.; Lim, C. S.

    2012-06-01

    The principal objective of this study was to determine the effects of the application of the adaptive statistical iterative reconstruction (ASIR) technique in combination with another two factors (body mass index (BMI) and tube potential) on radiation dose in cardiac computed tomography (CT). For quantitative analysis, regions of interest were positioned on the central region of the great coronary artery, the right coronary artery, and the left anterior descending artery, after which the means and standard deviations of measured CT numbers were obtained. For qualitative analysis, images taken from the major coronary arteries (right coronary, left anterior descending, and left circumflex) were graded on a scale of 1-5, with 5 indicating the best image quality. Effective dose, which was calculated by multiplying the value of the dose length product by a standard conversion factor of 0.017 for the chest, was employed as a measure of radiation exposure dose. In cardiac CT in patients with BMI of less than 25 kg/m2, the use of 40% ASIR in combination with a low tube potential of 100 kVp resulted in a significant reduction in the radiation dose without compromising diagnostic quality. Additionally, the combination of the 120 kVp protocol and the application of 40% ASIR application for patients with BMI higher than 25 kg/m2 yielded similar results.

  16. Radiological dose assessment related to management of naturally occurring radioactive materials generated by the petroleum industry

    International Nuclear Information System (INIS)

    Smith, K.P.; Blunt, D.L.; Williams, G.P.; Tebes, C.L.

    1995-01-01

    A preliminary radiological dose assessment related to equipment decontamination, subsurface disposal, landspreading, equipment smelting, and equipment burial was conducted to address concerns regarding the presence of naturally occurring radioactive materials in production waste streams. The assessment evaluated the relative dose of these activities and included a sensitivity analysis of certain input parameters. Future studies and potential policy actions are recommended

  17. Computational assessment of effective dose and patient specific doses for kilovoltage stereotactic radiosurgery of wet age-related macular degeneration

    Science.gov (United States)

    Hanlon, Justin Mitchell

    Age-related macular degeneration (AMD) is a leading cause of vision loss and a major health problem for people over the age of 50 in industrialized nations. The current standard of care, ranibizumab, is used to help slow and in some cases stabilize the process of AMD, but requires frequent invasive injections into the eye. Interest continues for stereotactic radiosurgery (SRS), an option that provides a non-invasive treatment for the wet form of AMD, through the development of the IRay(TM) (Oraya Therapeutics, Inc., Newark, CA). The goal of this modality is to destroy choroidal neovascularization beneath the pigment epithelium via delivery of three 100 kVp photon beams entering through the sclera and overlapping on the macula delivering up to 24 Gy of therapeutic dose over a span of approximately 5 minutes. The divergent x-ray beams targeting the fovea are robotically positioned and the eye is gently immobilized by a suction-enabled contact lens. Device development requires assessment of patient effective dose, reference patient mean absorbed doses to radiosensitive tissues, and patient specific doses to the lens and optic nerve. A series of head phantoms, including both reference and patient specific, was derived from CT data and employed in conjunction with the MCNPX 2.5.0 radiation transport code to simulate treatment and evaluate absorbed doses to potential tissues-at-risk. The reference phantoms were used to evaluate effective dose and mean absorbed doses to several radiosensitive tissues. The optic nerve was modeled with changeable positions based on individual patient variability seen in a review of head CT scans gathered. Patient specific phantoms were used to determine the effect of varying anatomy and gaze. The results showed that absorbed doses to the non-targeted tissues were below the threshold levels for serious complications; specifically the development of radiogenic cataracts and radiation induced optic neuropathy (RON). The effective dose

  18. Estimation of lung shunt fraction from simultaneous fluoroscopic and nuclear images

    Science.gov (United States)

    van der Velden, Sandra; Bastiaannet, Remco; Braat, Arthur J. A. T.; Lam, Marnix G. E. H.; Viergever, Max A.; de Jong, Hugo W. A. M.

    2017-11-01

    Radioembolisation with yttrium-90 (90Y) is increasingly used as a treatment of unresectable liver malignancies. For safety, a scout dose of technetium-99m macroaggregated albumin (99mTc-MAA) is used prior to the delivery of the therapeutic activity to mimic the deposition of 90Y. One-day procedures are currently limited by the lack of nuclear images in the intervention room. To cope with this limitation, an interventional simultaneous fluoroscopic and nuclear imaging device is currently being developed. The purpose of this simulation study was to evaluate the accuracy of estimating the lung shunt fraction (LSF) of the scout dose in the intervention room with this device and compare it against current clinical methods. Methods: A male and female XCAT phantom, both with two respiratory profiles, were used to simulate various LSFs resulting from a scout dose of 150 MBq 99mTc-MAA. Hybrid images were Monte Carlo simulated for breath-hold (5 s) and dynamic breathing (10 frames of 0.5 s) acquisitions. Nuclear images were corrected for attenuation with the fluoroscopic image and for organ overlap effects using a pre-treatment CT-scan. For comparison purposes, planar scintigraphy and mobile gamma camera images (both 300 s acquisition time) were simulated. Estimated LSFs were evaluated for all methods and compared to the phantom ground truth. Results: In the clinically relevant range of 10-20% LSF, hybrid imaging overestimated LSF with approximately 2 percentage points (pp) and 3 pp for the normal and irregular breathing phantoms, respectively. After organ overlap correction, LSF was estimated with a more constant error. Errors in planar scintigraphy and mobile gamma camera imaging were more dependent on LSF, body shape and breathing profile. Conclusion: LSF can be estimated with a constant minor error with a hybrid imaging device. Estimated LSF is highly dependent on true LSF, body shape and breathing pattern when estimated with current clinical methods. The hybrid

  19. SU-D-209-01: Can Fluoroscopic Air-Kerma Rates Be Reliably Measured with Solid-State Meters?

    International Nuclear Information System (INIS)

    Feng, C; Thai, L; Wagner, L; Ozus, B

    2016-01-01

    Purpose: Ionization chambers remain the standard for calibration of air-kerma rate measuring devices. Despite their strong energy-dependent response, solid state radiation detectors are increasingly used, primarily due to their efficiency in making standardized measurements. To test the reliability of these devices in measuring air-kerma rates, we compared ion chambers measurements with solid-state measurements for various mobile fluoroscopes operated at different beam qualities and air-kerma rates. Methods: Six mobile fluoroscopes (GE OEC models 9800 and 9900) were used to generate test beams. Using various field sizes and dose rate controls, copper attenuators and a lead attenuator were placed at the image receptor in varying combinations to generate a range of air-kerma rates. Air-kerma rates at 30 centimeters from the image receptors were measured using two 6-cm"3 ion chambers with electrometers (Radcal, models 1015 and 9015) and two with solid state detectors (Unfors Xi and Raysafe X2). No error messages occurred during measurements. However, about two months later, one solid-state device stopped working and was replaced by the manufacturer. Two out of six mobile fluoroscopic units were retested with the replacement unit. Results: Generally, solid state and ionization chambers agreed favorably well, with two exceptions. Before replacement of the detector, the Xi meter when set in the “RF High” mode deviated from ion chamber readings by factors of 2 and 10 with no message indicating error in measurement. When set in the “RF Low” mode, readings were within −4% to +3%. The replacement Xi detector displayed messages alerting the user when settings were not compatible with air-kerma rates. Conclusion: Air-kerma rates can be measured favorably well using solid-state devices, but users must be aware of the possibility that readings can be grossly in error with no discernible indication for the deviation.

  20. SU-D-209-01: Can Fluoroscopic Air-Kerma Rates Be Reliably Measured with Solid-State Meters?

    Energy Technology Data Exchange (ETDEWEB)

    Feng, C; Thai, L; Wagner, L [The University of Texas Health Science Center at Houston, Houston, TX (United States); Ozus, B [CHI St Luke’s Health, Baylor St Luke’s Medical Center, Houston, TX (United States)

    2016-06-15

    Purpose: Ionization chambers remain the standard for calibration of air-kerma rate measuring devices. Despite their strong energy-dependent response, solid state radiation detectors are increasingly used, primarily due to their efficiency in making standardized measurements. To test the reliability of these devices in measuring air-kerma rates, we compared ion chambers measurements with solid-state measurements for various mobile fluoroscopes operated at different beam qualities and air-kerma rates. Methods: Six mobile fluoroscopes (GE OEC models 9800 and 9900) were used to generate test beams. Using various field sizes and dose rate controls, copper attenuators and a lead attenuator were placed at the image receptor in varying combinations to generate a range of air-kerma rates. Air-kerma rates at 30 centimeters from the image receptors were measured using two 6-cm{sup 3} ion chambers with electrometers (Radcal, models 1015 and 9015) and two with solid state detectors (Unfors Xi and Raysafe X2). No error messages occurred during measurements. However, about two months later, one solid-state device stopped working and was replaced by the manufacturer. Two out of six mobile fluoroscopic units were retested with the replacement unit. Results: Generally, solid state and ionization chambers agreed favorably well, with two exceptions. Before replacement of the detector, the Xi meter when set in the “RF High” mode deviated from ion chamber readings by factors of 2 and 10 with no message indicating error in measurement. When set in the “RF Low” mode, readings were within −4% to +3%. The replacement Xi detector displayed messages alerting the user when settings were not compatible with air-kerma rates. Conclusion: Air-kerma rates can be measured favorably well using solid-state devices, but users must be aware of the possibility that readings can be grossly in error with no discernible indication for the deviation.

  1. Algorithm for assessment of mean annual gonad dose and genetically significant dose from the data of personal dosimetry

    International Nuclear Information System (INIS)

    Tomasevic, M.; Radovanovic, R.

    1986-01-01

    During one year more than 40,000 items of information on radiation exposure of personnel involved in the handling of radiation sources and more than 5,000,000 items on irradiation of other people are collected in the authors' laboratory. Considerable progress in assessment of mean annual gonad dose of genetically sifnificant dose was attained by means of an algorithm for a personal computer. This simple and inexpensive system has led to a higher accuracy in the application of protective measures. (author)

  2. Radiological Dose Calculations And Supplemental Dose Assessment Data For Neshap Compliance For SNL Nevada Facilities 1996.

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2017-05-01

    Operations of Sandia National Laboratories, Nevada (SNL/NV) at the Tonopah Test Range (TTR) resulted in no planned point radiological releases during 1996. Other releases from SNL/NV included diffuse transuranic sources consisting of the three Clean Slate sites. Air emissions from these sources result from wind resuspension of near-surface transuranic contaminated soil particulates. The total area of contamination has been estimated to exceed 20 million square meters. Soil contamination was documented in an aerial survey program in 1977 (EG&G 1979). Surface contamination levels were generally found to be below 400 pCi/g of combined plutonium-238, plutonium-239, plutonium-240, and americium-241 (i.e., transuranic) activity. Hot spot areas contain up to 43,000 pCi/g of transuranic activity. Recent measurements confirm the presence of significant levels of transuranic activity in the surface soil. An annual diffuse source term of 0.39 Ci of transuranic material was calculated for the cumulative release from all three Clean Slate sites. A maximally exposed individual dose of 1.1 mrem/yr at the TTR airport area was estimated based on the 1996 diffuse source release amounts and site-specific meteorological data. A population dose of 0.86 person-rem/yr was calculated for the local residents. Both dose values were attributable to inhalation of transuranic contaminated dust.

  3. Researches and Applications of ESR Dosimetry for Radiation Accident Dose Assessment

    International Nuclear Information System (INIS)

    Wu, K.; Guo, L.; Cong, J.B.; Sun, C.P.; Hu, J.M.; Zhou, Z.S.; Wang, S.; Zhang, Y.; Zhang, X.; Shi, Y.M.

    1998-01-01

    The aim of this work was to establish methods suitable for practical dose assessment of people involved in ionising radiation accidents. Some biological materials of the human body and materials possibly carried or worn by people were taken as detection samples. By using electron spin resonance (ESR) techniques, the basic dosimetric properties of selected materials were investigated in the range above the threshold dose of human acute haemopoietic radiation syndrome. The dosimetric properties involved included dose response properties of ESR signals, signal stabilities, distribution of background signals, the lowest detectable dose value, radiation conditions, environmental effects on the detecting process, etc. Several practical dose analytical indexes and detecting methods were set up. Some of them (bone, watch glass and tooth enamel) had also been successfully used in the dose assessment of people involved in three radiation accidents, including the Chernobyl reactor accident. This work further proves the important role of ESR techniques in radiation accident dose estimation. (author)

  4. Assessment of doses due to secondary neutrons received by patient treated by proton therapy

    International Nuclear Information System (INIS)

    Sayah, R.; Martinetti, F.; Donadille, L.; Clairand, I.; Delacroix, S.; De Oliveira, A.; Herault, J.

    2010-01-01

    Proton therapy is a specific technique of radiotherapy which aims at destroying cancerous cells by irradiating them with a proton beam. Nuclear reactions in the device and in the patient himself induce secondary radiations involving mainly neutrons which contribute to an additional dose for the patient. The author reports a study aimed at the assessment of these doses due to secondary neutrons in the case of ophthalmological and intra-cranial treatments. He presents a Monte Carlo simulation of the room and of the apparatus, reports the experimental validation of the model (dose deposited by protons in a water phantom, ambient dose equivalent due to neutrons in the treatment room, absorbed dose due to secondary particles in an anthropomorphic phantom), and the assessment with a mathematical phantom of doses dues to secondary neutrons received by organs during an ophthalmological treatment. He finally evokes current works of calculation of doses due to secondary neutrons in the case of intra-cranial treatments

  5. Assessment of dose level of ionizing radiation in army scrap

    International Nuclear Information System (INIS)

    Abdel Hamid, S. M.

    2010-12-01

    Radiation protection is the science of protecting people and the environment from the harmful effects of ionizing radiation, which includes both particle radiation and high energy radiation. Ionizing radiation is widely used in industry and medicine. Any human activity of nuclear technologies should be linked to the foundation of scientific methodology and baseline radiation culture to avoid risk of radiation and should be working with radioactive materials and expertise to understand, control practices in order to avoid risks that could cause harm to human and environment. The study was conducted in warehouses and building of Sudan air force Khartoum basic air force during September 2010. The goal of this study to estimate the radiation dose and measurement of radioactive contamination of aircraft scrap equipment and increase the culture of radiological safety as well as the concept of radiation protection. The results showed that there is no pollution observed in the contents of the aircraft and the spire part stores outside, levels of radiation dose for the all contents of the aircraft and spire part within the excitable level, except temperature sensors estimated radiation dose about 43 μSv/h outside of the shielding and 12 μSv/h inside the shielding that exceeded the internationally recommended dose level. One of the most important of the identification of eighteen (18) radiation sources used in temperature and fuel level sensors. These are separated from the scrap, collected and stored in safe place. (Author)

  6. Assessment of pediatrics radiation dose from routine x-ray ...

    African Journals Online (AJOL)

    Background: Given the fact that children are more sensitive to ionizing radiation than adults,with an increased risk of developing radiation-induced cancer,special care should be taken when they undergo X-ray examinations. The main aim of the current study was to determine Entrance Surface Dose (ESD) to pediatric ...

  7. Radiation protection cabin for catheter-directed liver interventions: operator dose assessment

    International Nuclear Information System (INIS)

    Maleux, Geert; Bosmans, Hilde; Bergans, Niki; Bogaerts, Ria

    2016-01-01

    The number and complexity of interventional radiological procedures and in particular catheter-directed liver interventions have increased substantially. The current study investigates the reduction of personal doses when using a dedicated radiation protection cabin (RPC) for these procedures. Operator and assistant doses were assessed for 3 series of 20 chemo-infusion/chemoembolisation interventions, including an equal number of procedures with and without RPC. Whole body doses, finger doses and doses at the level of knees and eyes were evaluated with different types of TLD-100 Harshaw dosemeters. Dosemeters were also attached on the three walls of the RPC. The operator doses were significantly reduced by the RPC, but also without RPC, the doses appear to be limited as a result of thorough optimisation with existing radiation protection tools. The added value of the RPC should thus be determined by the outcome of balancing dose reduction and other aspects such as ergonomic benefits. (authors)

  8. An objective spinal motion imaging assessment (OSMIA): reliability, accuracy and exposure data.

    OpenAIRE

    Breen, Alan C.; Muggleton, J.M.; Mellor, F.E.

    2006-01-01

    Abstract Background Minimally-invasive measurement of continuous inter-vertebral motion in clinical settings is difficult to achieve. This paper describes the reliability, validity and radiation exposure levels in a new Objective Spinal Motion Imaging Assessment system (OSMIA) based on low-dose fluoroscopy and image processing. Methods Fluoroscopic sequences in coronal and sagittal planes were obtained from 2 calibration models using dry lumbar vertebrae, plus the lumbar spines of 30 asymptom...

  9. Cancer mortality in women after repeated fluoroscopic examinations of the chest

    International Nuclear Information System (INIS)

    Boice, J.D.; Monson, R.R.; Rosenstein, M.

    1981-01-01

    Among 1,047 women fluoroscopically examined in average of 102 times during pneumothorax therapy for tuberculosis and followed up to 45 years (average . 27 yr), no increase in the total number of cancer deaths occurred when these women were compared to 717 women who received other treatments [relative risk (RR) . 0.8]. However, elevated risks of mortality from stomach cancer (RR . 2.3), rectal cancer (RR . 3.8), breast cancer (RR . 1.2), lung cancer (RR . 1.8), and leukemia (RR . 1.2) were observed, but none was statistically significant and all were based on very small numbers of deaths. These increases were balanced by decreases of genital cancer (RR . 0.2), pancreatic cancer (RR . 0.9), lymphoma (RR . 0.6), and all other cancers (RR . 0.1). Average cumulative absorbed doses were 110 rads for the lungs, 33 rads for the trunk, 13 rads for the active bone marrow, and 7 rads for the stomach. The following upper levels of excess risk could be excluded with 95% confidence: 3.5 deaths/10(6) woman-year (WY)-rad for lung cancer, 4.8 deaths/10(6) WY-rad for lymphoma, and 12 deaths/10(6) WY-rad for leukemia. These findings indicated that the carcinogenic effect of multiple low-dose X-ray exposures was not greater than that currently assumed

  10. Diagnostic value of the fluoroscopic triggering 3D LAVA technique for primary liver cancer.

    Science.gov (United States)

    Shen, Xiao-Yong; Chai, Chun-Hua; Xiao, Wen-Bo; Wang, Qi-Dong

    2010-04-01

    Primary liver cancer (PLC) is one of the common malignant tumors. Liver acquisition with acceleration volume acquisition (LAVA), which allows simultaneous dynamic enhancement of the hepatic parenchyma and vasculature imaging, is of great help in the diagnosis of PLC. This study aimed to evaluate application of the fluoroscopic triggering 3D LAVA technique in the imaging of PLC and liver vasculature. The clinical data and imaging findings of 38 adults with PLC (22 men and 16 women; average age 52 years), pathologically confirmed by surgical resection or biopsy, were collected and analyzed. All magnetic resonance images were obtained with a 1.5-T system (General Electrics Medical Systems) with an eight-element body array coil and application of the fluoroscopic triggering 3D LAVA technique. Overall image quality was assessed on a 5-point scale by two experienced radiologists. All the nodules and blood vessel were recorded and compared. The diagnostic accuracy and feasibility of LAVA were evaluated. Thirty-eight patients gave high quality images of 72 nodules in the liver for diagnosis. The accuracy of LAVA was 97.2% (70/72), and the coincidence rate between the extent of tumor judged by dynamic enhancement and pathological examination was 87.5% (63/72). Displayed by the maximum intensity projection reconstruction, nearly all cases gave satisfactory images of branches III and IV of the hepatic artery. Furthermore, small early-stage enhancing hepatic lesions and the parallel portal vein were also well displayed. Sequence of LAVA provides good multi-phase dynamic enhancement scanning of hepatic lesions. Combined with conventional scanning technology, LAVA effectively and safely displays focal hepatic lesions and the relationship between tumor and normal tissues, especially blood vessels.

  11. Developing a flexible and verifiable integrated dose assessment capability

    International Nuclear Information System (INIS)

    Parzyck, D.C.; Rhea, T.A.; Copenhaver, E.D.; Bogard, J.S.

    1987-01-01

    A flexible yet verifiable system of computing and recording personnel doses is needed. Recent directions in statutes establish the trend of combining internal and external doses. We are developing a Health Physics Information Management System (HPIMS) that will centralize dosimetry calculations and data storage; integrate health physics records with other health-related disciplines, such as industrial hygiene, medicine, and safety; provide a more auditable system with published algorithms and clearly defined flowcharts of system operation; readily facilitate future changes dictated by new regulations, new dosimetric models, and new systems of units; and address ad-hoc inquiries regarding worker/workplace interactions, including potential synergisms with non-radiation exposures. The system is modular and provides a high degree of isolation from low-level detail, allowing flexibility for changes without adversely affecting other parts of the system. 10 refs., 3 figs

  12. Application of probabilistic quantitative ecological risk assessment to radiological dose

    International Nuclear Information System (INIS)

    Twining, J.; Ferris, J.; Copplestone, D.; Zinger, I.

    2004-01-01

    Probabilistic ERA is becoming more accepted and applied in evaluations of environmental impacts worldwide. In a previous paper we have shown that the process can be applied in practice to routine effluent releases from a nuclear facility. However, there are practical issues that need to be addressed prior to its regulatory application for criteria setting or for site-specific ERA. Among these issues are a) appropriate data selection for both exposure and dose-response input, because there is a need to carefully characterise and filter the available dose-response data for its ecological relevance, b) A coherent approach is required to the choice of exposure scenarios, and c) there are various questions associated with treatment of exposure to mixed nuclides. In this paper we will evaluate and discuss aspects of these issues, using an illustrative case study approach. (author)

  13. Absorbed dose assessment in newborns during x-ray examinations

    Science.gov (United States)

    Taipe, Patricia K.; Berrocal, Mariella J.; Carita, Raúl F.

    2012-02-01

    Often a newborn presents breathing problems during the early days of life, i.e. bronchopneumonia, wich are caused in most of cases, by aspirating a mixture of meconium and amniotic fluid. In these cases, it is necessary to make use of a radiograph, requested by the physician to reach a diagnosis. This paper seeks to evaluate the absorbed doses in neonates undergoing a radiograph. For this reason we try to simulate the real conditions in a X-ray room from Lima hospitals. With this finality we perform a simulation made according a questionnaire related to technical data of X-ray equipment, distance between the source and the neonate, and its position to be irradiated. The information obtained has been used to determine the absorbed dose by infants, using the MCNP code. Finally, the results are compared with reference values of international health agencies.

  14. Assessment of individual doses and intervention planning at CERN

    International Nuclear Information System (INIS)

    Brugger, M.; Forkel-Wirth, D.; Gaborit, J.C.; Menzel, H.; Roesler, S.

    2006-01-01

    Founded in 1954, CERN is the European Organization for Nuclear Research, one of the world's largest international particle physics centres. It sits astride the Franco-Swiss border near Geneva. The Large Hadron Collider (LHC) is currently being installed in a 27-kilometer ring tunnel, buried deep below the countryside on the outskirts of Geneva, Switzerland and the Pays de Gex, France. When its operation begins in 2007, the LHC will be the world's most power particle accelerator. The start-up and the operation of the LHC will mark a new era for CERN's operational radiation protection. The total surface of CERN's radiation areas will enlarge significantly and a large number of work places have to be regularly monitored by CERN's radiation protection group. The maintenance personnel will comprise CERN staff, outside contractors and a large number of physicists from all over the world. CERN meets this challenge by applying optimisation processes already in the design of accelerator and detector components and by an appropriate intervention and dose planning during operation. Detailed Monte Carlo calculations were performed during the design phase of the LHC and were used to identify the potential radiation hazards during future maintenance in areas with elevated beam losses (accelerator ejection and injection, beam dumps, target areas or beam cleaning insertions) and thus elevated dose rates. In an iterative way, the design of the accelerator components and the layout of these regions were optimised. The impact of the proposed modifications on the dose to personnel was evaluated by Monte Carlo simulations. Calculated individual and collective doses were then compared to design constraints. (author)

  15. Assessment of Individual Doses and Intervention Planning at CERN

    International Nuclear Information System (INIS)

    Brugger, M.; Forkel-Wirth, D.; Gaborit, J.C.; Menzel, H.; Roesler, S.; Vincke, H.

    2006-01-01

    Founded in 1954, CERN is the European Organization for Nuclear Research, one of the world's largest international particle physics centres. It sits astride the Franco-Swiss border near Geneva. The Large Hadron Collider (Lhc) is currently being installed in a 27-kilometer ring tunnel, buried deep below the countryside on the outskirts of Geneva, Switzerland and the Pays de Gex, France. When its operation begins in 2007, the Lhc will be the world's most powerful particle accelerator. The start-up and the operation of the Lhc will mark a new era for CERN's operational radiation protection. The total surface of CERN's radiation areas will enlarge significantly and a large number of work places have to be regularly monitored by CERN's radiation protection group. The maintenance personnel will comprise CERN staff, outside contractors and a large number of physicists from all over the world. CERN meets this challenge by applying optimisation processes already in the design of accelerator and detector components and by an appropriate intervention and dose planning during operation. Detailed Monte Carlo calculations were performed during the design phase of the Lhc and were used to identify the potential radiation hazards during future maintenance in areas with elevated beam losses (accelerator ejection and injection, beam dumps, target areas or beam cleaning insertions) and thus elevated dose rates. In an iterative way, the design of the accelerator components and the layout of these regions were optimised. The impact of the proposed modifications on the dose to personnel was evaluated by Monte Carlo simulations. Calculated individual and collective doses were then compared to design constraints. (authors)

  16. Implementation of a competency check-off in diagnostic fluoroscopy for radiology trainees: impact on reducing radiation for three common fluoroscopic exams in children

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Sweta [University of Missouri-Kansas City SOM, Department of Radiology, Kansas City, MO (United States); Desouches, Stephane L. [University of Missouri-Kansas City SOM, Department of Radiology, Kansas City, MO (United States); St. Luke' s Hospital, Department of Radiology, Kansas City, MO (United States); Lowe, Lisa H.; Kasraie, Nima; Reading, Brenton [University of Missouri-Kansas City SOM, Department of Radiology, Kansas City, MO (United States); Children' s Mercy Hospitals and Clinics, Department of Radiology, Kansas City, MO (United States)

    2014-07-24

    Fluoroscopy is an important tool for diagnosis in the pediatric population, but it carries the risk of radiation exposure. Because radiology resident education and experience in the use of fluoroscopy equipment in children vary, we implemented an intervention to standardize fluoroscopy training. The purpose of this study is to determine the impact of implementing a fluoroscopy competency check-off for radiology resident trainees aimed at decreasing radiation exposure in three common pediatric fluoroscopic studies. A fluoroscopy competency check-off form was developed for radiology resident trainees performing pediatric procedures. Techniques used to limit radiation exposure for common pediatric radiologic studies were reviewed as part of the check-off process. Pediatric radiologists supervised each trainee until they demonstrated competence to independently perform three specified procedures. Radiation dose was recorded for the three procedures, upper GI (UGI), voiding cystourethrogram (VCUG) and oropharyngeal (OPM) exams, over 6 months preceding and 6 months following implementation of the competency check-off. The mean cumulative dose for each procedure was compared before and after implementation of competency check-off using a Kruskal-Wallis test. During the 12-month study period doses from 909 fluoroscopic procedures were recorded. In the 6 months preceding competency check-off implementation, procedures were performed by 24 radiology resident trainees including 171 UGI, 176 VCUG and 171 OPM exams. In the 6 months following competency check-off, 23 trainees performed 114 UGI, 145 VCUG and 132 OPM exams. After competency check-off implementation, a statistically significant reduction in average radiation dose was found for all three studies (P < 0.001). Median cumulative doses (mGy) were decreased by 33%, 36% and 13% for UGIs, VCUGs and OPMs, respectively. Implementation of a competency check-off for radiology resident trainees can reduce average radiation

  17. Implementation of a competency check-off in diagnostic fluoroscopy for radiology trainees: impact on reducing radiation for three common fluoroscopic exams in children

    International Nuclear Information System (INIS)

    Shah, Sweta; Desouches, Stephane L.; Lowe, Lisa H.; Kasraie, Nima; Reading, Brenton

    2015-01-01

    Fluoroscopy is an important tool for diagnosis in the pediatric population, but it carries the risk of radiation exposure. Because radiology resident education and experience in the use of fluoroscopy equipment in children vary, we implemented an intervention to standardize fluoroscopy training. The purpose of this study is to determine the impact of implementing a fluoroscopy competency check-off for radiology resident trainees aimed at decreasing radiation exposure in three common pediatric fluoroscopic studies. A fluoroscopy competency check-off form was developed for radiology resident trainees performing pediatric procedures. Techniques used to limit radiation exposure for common pediatric radiologic studies were reviewed as part of the check-off process. Pediatric radiologists supervised each trainee until they demonstrated competence to independently perform three specified procedures. Radiation dose was recorded for the three procedures, upper GI (UGI), voiding cystourethrogram (VCUG) and oropharyngeal (OPM) exams, over 6 months preceding and 6 months following implementation of the competency check-off. The mean cumulative dose for each procedure was compared before and after implementation of competency check-off using a Kruskal-Wallis test. During the 12-month study period doses from 909 fluoroscopic procedures were recorded. In the 6 months preceding competency check-off implementation, procedures were performed by 24 radiology resident trainees including 171 UGI, 176 VCUG and 171 OPM exams. In the 6 months following competency check-off, 23 trainees performed 114 UGI, 145 VCUG and 132 OPM exams. After competency check-off implementation, a statistically significant reduction in average radiation dose was found for all three studies (P < 0.001). Median cumulative doses (mGy) were decreased by 33%, 36% and 13% for UGIs, VCUGs and OPMs, respectively. Implementation of a competency check-off for radiology resident trainees can reduce average radiation

  18. Radon dose assessment in underground mines in Brazil

    International Nuclear Information System (INIS)

    Santos, T.O.; Rocha, Z.; Cruz, P.; Gouvea, V.A.; Siqueira, J.B.; Oliveira, A.H.

    2014-01-01

    Underground miners are internally exposed to radon, thoron and their short-lived decay products during the mineral processing. There is also an external exposure due to the gamma emitters present in the rock and dust of the mine. However, the short-lived radon decay products are recognised as the main radiation health risk. When inhaled, they are deposited in the respiratory system and may cause lung cancer. To address this concern, concentration measurements of radon and its progeny were performed, the equilibrium factor was determined and the effective dose received was estimated in six Brazilian underground mines. The radon concentration was measured by using E-PERM, AlphaGUARD and CR-39 detectors. The radon progeny was determined by using DOSEman. The annual effective dose for the miners was estimated according to United Nations Scientific Committee on the Effects of Atomic Radiation methodologies. The mean value of the equilibrium factor was 0.4. The workers' estimated effective dose ranged from 1 to 21 mSv a -1 (mean 9 mSv a -1 ). (authors)

  19. Identification of arteries and veins in cerebral angiography fluoroscopic images

    Science.gov (United States)

    Andra Tache, Irina

    2017-11-01

    In the present study a new method for pixels tagging into arteries and veins classes from temporal cerebral angiography is presented. This need comes from the neurosurgeon who is evaluating the fluoroscopic angiography and the magnetic resonance images from the brain in order to locate the fistula of the patients who suffer from arterio-venous malformation. The method includes the elimination of the background pixels from a previous segmentation and the generation of the time intensity curves for each remaining pixel. The later undergo signal processing in order to extract the characteristic parameters needed for applying the k-means clustering algorithm. Some of the parameters are: the phase and the maximum amplitude extracted from the Fourier transform, the standard deviation and the mean value. The tagged classes are represented into images which then are re-classified by an expert into artery and vein pixels.

  20. High-speed rotary atherectomy under fluoroscopic and angioscopic guidance

    International Nuclear Information System (INIS)

    Deutsch, L.S.; Ahn, S.S.; Yeatman, L.A.; Marcus, D.R.; Auth, D.P.; Moore, W.S.

    1988-01-01

    This paper describes thirteen stenotic arteries treated by high-speed rotary abrasive burr atherectomy performed in the operating room under fluoroscopic-angioscopic control by a multidisciplinary team consisting of a vascular surgeon, an interventional radiologist, and an interventional cardiologist. Incrementally sized atherectomy burrs were used in each patient (1.75-4.0 mm in diameter). Rotary artherectomy was successful in 11 of 13 arteries ranging from 1 to 40 cm (median, 5 cm) with stenoses ranging from 50% to 99% (median, 90%), which improved to less than 30% in all 11 successfully atherectomized segments. Two early posttreatment failures (intimal dissection, burr shaft disruption), two posttreatment thromboses (unrelated to atherectomy), and two late failures (restenosis) occurred

  1. Equine scintigraphy: assessment of the dose received by the personnel; Scintigraphie equine: estimation de la dose recue par le personnel

    Energy Technology Data Exchange (ETDEWEB)

    Clairand, I.; Bottollier, J.F.; Trompier, F. [Institut de Radioprotection et de Surete Nucleaire IRSN, 92 - Fontenay aux Roses (France)

    2003-03-01

    Following a request from the Permanent Secretary of the French Commission for Artificial Radioelements (CIREA) engaged to investigate a request for a licence related to a new scintigraphy unit dedicated to equidae, a dosimetric assessment concerning the personnel attending the examination was carried out. This scintigraphy unit depends on the Goustranville Centre for Imaging and Research on the Locomotive Diseases of Equidae (CIRALE) in the Calvados region. The dosimetric assessment was carried out for the different operators during the successive stages of the scintigraphic examination. Assuming 150 examinations per year, the annual equivalent dose to the fingers skin is 150 mSv maximum for the technologist and 2 mSv for the veterinary surgeon; the annual effective dose ranges from 0.15 to 0.45 mSv, depending on the operators. (authors)

  2. Lung tumor tracking in fluoroscopic video based on optical flow

    International Nuclear Information System (INIS)

    Xu Qianyi; Hamilton, Russell J.; Schowengerdt, Robert A.; Alexander, Brian; Jiang, Steve B.

    2008-01-01

    Respiratory gating and tumor tracking for dynamic multileaf collimator delivery require accurate and real-time localization of the lung tumor position during treatment. Deriving tumor position from external surrogates such as abdominal surface motion may have large uncertainties due to the intra- and interfraction variations of the correlation between the external surrogates and internal tumor motion. Implanted fiducial markers can be used to track tumors fluoroscopically in real time with sufficient accuracy. However, it may not be a practical procedure when implanting fiducials bronchoscopically. In this work, a method is presented to track the lung tumor mass or relevant anatomic features projected in fluoroscopic images without implanted fiducial markers based on an optical flow algorithm. The algorithm generates the centroid position of the tracked target and ignores shape changes of the tumor mass shadow. The tracking starts with a segmented tumor projection in an initial image frame. Then, the optical flow between this and all incoming frames acquired during treatment delivery is computed as initial estimations of tumor centroid displacements. The tumor contour in the initial frame is transferred to the incoming frames based on the average of the motion vectors, and its positions in the incoming frames are determined by fine-tuning the contour positions using a template matching algorithm with a small search range. The tracking results were validated by comparing with clinician determined contours on each frame. The position difference in 95% of the frames was found to be less than 1.4 pixels (∼0.7 mm) in the best case and 2.8 pixels (∼1.4 mm) in the worst case for the five patients studied.

  3. Problems Concerning Dose Assessments in Epidemiology of High Background Radiation Areas of Yangjiang, China (invited paper)

    International Nuclear Information System (INIS)

    Wei, L.X.; Yuan, Y.L.

    1998-01-01

    The purpose of this study on radiation levels and dose assessments in the epidemiology of a high background radiation area (HBRA) and the control area (CA) is to respond to the needs of epidemiology in these areas, where the inhabitants are continuously exposed to low dose, low dose rate ionising radiation. A brief description is given of how the research group evaluated the feasibility of the investigation by analysing the population size and the radiation levels, how simple reliable methods were used to get the individual annual dose for every cohort member, and how the cohort members were classified into various dose groups for dose-effect relationship analysis. Finally, the use of dose group classification for cancer mortality studies is described. (author)

  4. WAYS TO INCREASE ACCURACY AND RELIABILITY OF INDIVIDUAL DOSES ASSESSMENTS IN PERSONNEL WITHIN THERMOLUMINESCENCE TECHNIQUE

    Directory of Open Access Journals (Sweden)

    G. N. Kaydanovskiy

    2012-01-01

    Full Text Available The paper analyses the main sources of measurement errors of individual doses in personnel performed within the thermoluminescence technique and gives recommendations to minimize these errors. The reasons that reduce reliability of effective dose assessments derived from measured values of personal dose equivalent are imperfections of guidance documents. Changes to the Guidelines «Organization and implementation of individual dosimetric control. Staff of health institutions» are justified.

  5. Assessment of dose inhomogeneity at target level by in vivo dosimetry

    International Nuclear Information System (INIS)

    Leunens, G.; Verstraete, J.; Dutreix, A.; Schueren, E. van der

    1992-01-01

    Inhomogeneity of dose delivered to the target volume due to irregular body surface and tissue densities remains in many cases unknown, since dose distribution is calculated for most radiation treatments in only one transverse section and assuming the patient to be water equivalent. In this study transmission and target absorbed dose homogeneity is assessed for 11 head-and-neck cancer treatments by in vivo measurements with silicon diodes. Besides the dose to specification point, the dose delivered to 2-4 off-axis points in midline sagittal plane is estimated from entrance and exit dose measurements. Simultaneously made portal films allow to identify anatomical structures passed by the beam before reaching exit diode. Mean deviation from expected transmission is -6.8% for bone, +6% for air cavities and -2.5% for soft tissue. At midplane, mean deviations from expected target dose are respectively -3.5%, +2.3% and -1.9%. Deviations from prescribed dose are larger than 5% in 12/39 target points. Accuracy requirements in target dose delivery of plus or minus 5%, as proposed by ICRU, cannot be fulfilled in 7/11 patients and is mostly due to irregular body contour and tissue densities. as only a limited number of points are considered, inhomogeneity in dose delivered throughout whole irradiated volume is underestimated, as is illustrated from exit dose profiles obtained from portal image. Besides its tremendous value as a quality assurance procedure, in vivo dose measurements are shown to be a valid method for assessing dose delivered to irradiated tissues when dose computations are assumed to be inaccurate or even impossible in current practice. (author). 21 refs., 8 figs., 1 tab

  6. Assessment of medical occupational radiation doses in Costa Rica

    International Nuclear Information System (INIS)

    Mora, P.; Acuna, M.

    2011-01-01

    Participation of the Univ. of Costa Rica (UCR) in activities in an IAEA Regional Project RLA/9/066 through training, equipment and expert missions, has enabled to setting up of a national personal monitoring laboratory. Since 2007, the UCR has been in charge of monitoring around 1800 medical radiation workers of the Social Security System. Individual external doses are measured with thermoluminescent dosemeter using a Harshaw 6600 Plus reader. The service has accreditation with ISO/IEC 17025:2005. Distribution of monitored medical personnel is as follows: 83 % in diagnostic radiology, 6 % in nuclear medicine and 6 % in radiotherapy. Preliminary values for the 75 percentile of annual H p (10) in mSv are: radiology 0.37; interventional radiology 0.41; radiotherapy 0.53 and nuclear medicine 1.55. The service provided by the UCR in a steady and reliable way can help to implement actions to limit the doses received by the medical workers and optimise their radiation protection programs. (authors)

  7. Assessment of medical occupational radiation doses in Costa Rica.

    Science.gov (United States)

    Mora, P; Acuña, M

    2011-09-01

    Participation of the University of Costa Rica (UCR) in activities in an IAEA Regional Project RLA/9/066 through training, equipment and expert missions, has enabled to setting up of a national personal monitoring laboratory. Since 2007, the UCR has been in charge of monitoring around 1800 medical radiation workers of the Social Security System. Individual external doses are measured with thermoluminescent dosemeter using a Harshaw 6600 Plus reader. The service has accreditation with ISO/IEC 17025:2005. Distribution of monitored medical personnel is as follows: 83 % in diagnostic radiology, 6 % in nuclear medicine and 6 % in radiotherapy. Preliminary values for the 75 percentile of annual H(p)(10) in mSv are: radiology 0.37; interventional radiology 0.41; radiotherapy 0.53 and nuclear medicine 1.55. The service provided by the UCR in a steady and reliable way can help to implement actions to limit the doses received by the medical workers and optimise their radiation protection programs.

  8. Facial exposure dose assessment during intraoral radiography by radiological technologists

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Hwan; Yang, Han Joon [Dept. of International Radiological Science, Hallym University of Graduate Studies, Chuncheon (Korea, Republic of)

    2014-09-15

    The study examined the changes in the decreased facial exposure dose for radiological technologists depending on increased distance between the workers and the X-ray tube head during intraoral radiography. First, the facial phantom similar to the human tissues was manufactured. The shooting examination was configured to the maxillary molars for adults (60 kVp, 10 mA, 50 msec) and for children (60 kVp, 10 mA, 20 msec), and the chamber was fixed where the facial part of the radiation worker would be placed using the intraoral radiography equipment. The distances between the X-ray tube head and the phantom were set to 10 cm, 15 cm, 20 cm, 25 cm, 30 cm, 35 cm, and 40 cm. The phantom was radiated 20 times with each examination condition and the average scattered doses were examined. The rate at the distance of 40 cm decreased by about 92.6% to 7.43% based on the scattered rays radiated at the distance of 10 cm under the adult conditions. The rate at the distance of 40 cm decreased by about 97.6% to 2.58% based on the scattered rays radiated at the distance of 10 cm under the children conditions. Protection from the radiation exposure was required during the dental radiographic examination.

  9. Improvement of Off-site Dose Assessment Code for Operating Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Juyub; Kim, Juyoul; Shin, Kwangyoung [FNC Technology Co. Ltd., Yongin (Korea, Republic of); You, Songjae; Moon, Jongyi [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2014-05-15

    XOQDOQ code which calculates atmospheric Dispersion factor was included into INDAC also. A research on the improvement of off-site dose assessment system for an operating nuclear power plant was performed by KINS in 2011. As a result, following improvements were derived: - Separation of dose assessment for new and existing facilities - Update of food ingestion data - Consideration of multi-unit operation and so on In order to reflect the results, INDAC is under modification. INDAC is an integrated dose assessment code for an operating nuclear power plant and consists of three main modules: XOQDOQ, GASDOS and LIQDOS. The modules are under modification in order to improve the accuracy of assessment and usability. Assessment points for multi-unit release can be calculated through the improved code and the method on dose assessment for multi-unit release has been modified, so that the dose assessment result of multi-unit site becomes more realistic by relieving excessive conservatism. Finally, as the accuracy of calculation modules has been improved, the reliability of dose assessment result has been strengthened.

  10. Establishment of exposure dose assessment laboratory in National Radiation Emergency Medical Center (NREMC)

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Jae Ryong; Ha, Wi Ho; Yoon, Seok Won; Han, Eun Ae; Lee, Seung Sook [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2011-10-15

    As unclear industry grown, 432 of the nuclear power plants are operating and 52 of NPPs are under construction currently. Increasing use of radiation or radioisotopes in the field of industry, medical purpose and research such as non-destructive examination, computed tomography and x-ray, etc. constantly. With use of nuclear or radiation has incidence possibility for example the Fukushima NPP incident, the Goiania accident and the Chernobyl Nuclear accident. Also the risk of terror by radioactive material such as Radiological Dispersal Device(RDD) etc. In Korea, since the 'Law on protection of nuclear facilities and countermeasure for radioactive preparedness was enacted in 2003, the Korean institute of Radiological and Medical Sciences(KIRAMS) was established for the radiation emergency medical response in radiological disaster due to nuclear accident, radioactive terror and so on. Especially National Radiation Emergency Medical Center(NREMC) has the duty that is protect citizens from nuclear, radiological accidents or radiological terrors through the emergency medical preparedness. The NREMC was established by the 39-article law on physical protection of nuclear material and facilities and measures for radiological emergencies. Dose assessment or contamination survey should be performed which provide the radiological information for medical response. For this reason, the NREMC establish and re-organized dose assessment system based on the existing dose assessment system of the NREMC recently. The exposure dose could be measured by physical and biological method. With these two methods, we can have conservative dose assessment result. Therefore the NREMC established the exposure dose assessment laboratory which was re-organized laboratory space and introduced specialized equipment for dose assessment. This paper will report the establishment and operation of exposure dose assessment laboratory for radiological emergency response and discuss how to enhance

  11. Measurement and assessment of doses from external radiations required for revised radiation protection regulations

    International Nuclear Information System (INIS)

    Tsujimura, Norio; Kojima, Noboru; Hayashi, Naomi

    2001-01-01

    Radiation protection regulations based on the 1990 recommendations of ICRP have been revised and will take effect from Apr., 2001. The major changes concerning on the measurement and assessment of doses from external radiations are as follows. (1) Personal dose equivalent and ambient dose equivalent stated in ICRP Publication 74 are introduced as quantities to be measured with personal dosimeters and survey instruments, respectively. (2) For multiple dosimetry for workers, the compartment weighting factors used for a realistic assessment of effective dose are markedly changed. In advance of the introduction of the new radiation protection regulations, the impacts on workplace and personal monitoring for external radiations by these revisions were investigated. The following results were obtained. (1) A new ambient dose equivalent to neutrons is higher with a factor of 1.2 than the old one for moderated fission neutron spectra. Therefore, neutron dose equivalent monitors for workplace monitoring at MOX fuel for facilities should be recalibrated for measurement of the new ambient dose equivalent. (2) Annual effective doses of workers were estimated by applying new calibration factors to readings of personal dosimeters, worn by workers. Differences between effective doses and effective dose equivalents are small for workers engaged in the fabrication process of MOX fuel. (author)

  12. EMP Attachment 3 DOE-SC PNNL Site Dose Assessment Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, Sandra F.

    2011-12-21

    This Dose Assessment Guidance (DAG) describes methods to use to determine the Maximally-Exposed Individual (MEI) location and to estimate dose impact to that individual under the U.S. Department of Energy Office of Science (DOE-SC) Pacific Northwest National Laboratory (PNNL) Site Environmental Monitoring Plan (EMP). This guidance applies to public dose from radioactive material releases to the air from PNNL Site operations. This document is an attachment to the Pacific Northwest National Laboratory (PNNL) Environmental Monitoring Plan (EMP) and describes dose assessment guidance for radiological air emissions. The impact of radiological air emissions from the U.S. Department of Energy Office of Science (DOE-SC) PNNL Site is indicated by dose estimates to a maximally exposed member of the public, referred to as the maximally exposed individual (MEI). Reporting requirements associated with dose to members of the public from radiological air emissions are in 40 CFR Part 61.94, WAC 246-247-080, and DOE Order 458.1. The DOE Order and state standards for dose from radioactive air emissions are consistent with U.S. Environmental Protection Agency (EPA) dose standards in 40 CFR 61.92 (i.e., 10 mrem/yr to a MEI). Despite the fact that the current Contract Requirements Document (CRD) for the DOE-SC PNNL Site operations does not include the requirement to meet DOE CRD 458.1, paragraph 2.b, public dose limits, the DOE dose limits would be met when EPA limits are met.

  13. Measurement and assessment of doses from external radiations required for revised radiation protection regulations

    Energy Technology Data Exchange (ETDEWEB)

    Tsujimura, Norio; Kojima, Noboru; Hayashi, Naomi [Japan Nuclear Cycle Development Inst., Tokai, Ibaraki (Japan)

    2001-06-01

    Radiation protection regulations based on the 1990 recommendations of ICRP have been revised and will take effect from Apr., 2001. The major changes concerning on the measurement and assessment of doses from external radiations are as follows. (1) Personal dose equivalent and ambient dose equivalent stated in ICRP Publication 74 are introduced as quantities to be measured with personal dosimeters and survey instruments, respectively. (2) For multiple dosimetry for workers, the compartment weighting factors used for a realistic assessment of effective dose are markedly changed. In advance of the introduction of the new radiation protection regulations, the impacts on workplace and personal monitoring for external radiations by these revisions were investigated. The following results were obtained. (1) A new ambient dose equivalent to neutrons is higher with a factor of 1.2 than the old one for moderated fission neutron spectra. Therefore, neutron dose equivalent monitors for workplace monitoring at MOX fuel for facilities should be recalibrated for measurement of the new ambient dose equivalent. (2) Annual effective doses of workers were estimated by applying new calibration factors to readings of personal dosimeters, worn by workers. Differences between effective doses and effective dose equivalents are small for workers engaged in the fabrication process of MOX fuel. (author)

  14. Development of dose assessment code for accidental releases of activation products

    International Nuclear Information System (INIS)

    Noguchi, H.; Yokoyama, S.

    2000-01-01

    It is expected that activation products will be important radionuclides as well as tritium in the assessment of the public doses necessary for licensing of a future fusion reactor. In order to calculate the public doses due to the activation products released in cases of accidents, a code named ACUTAP (dose assessment code for ACUTe Activation Product releases) has been developed. Major characteristics of the code are as follows: (1) the transfer model reflects specific behavior of the activation products in the environment, (2) the doses are assessed based on ICRP dose models, (3) it is possible to calculate individual doses using annual meteorological data statistically according to the guide of the Nuclear Safety Commission of Japan, and (4) the code can calculate collective doses as well as individual doses. Individual doses are calculated for the following pathways: internal exposure by inhalation of activation products in a plume and those resuspended from the ground, external exposure from a plume (cloudshine), and external exposure from activation products deposited on the ground (groundshine). The inhalation in a plume and cloudshine pathways are included in the model for calculating collective doses. In addition to parent nuclides released from the facilities, progeny nuclides produced during the atmospheric dispersion are considered in calculating inhalation doses, and those during the deposition period in calculating groundshine doses. External doses from the cloudshine are calculated for 18 energy groups instead of individual energy of emitted gamma rays in order to save the computation time. Atmospheric concentrations are calculated using a Gaussian plume model with atmospheric dispersion parameters prescribed in the guide of the Nuclear Safety Commission of Japan. Data sets of parameters necessary for the dose assessment, such as internal dos coefficients, external dose rate conversion factors and half lives, are prepared for about 100 radionuclides

  15. Monitoring of high-radiation areas for the assessment of operational and body doses

    International Nuclear Information System (INIS)

    Chen, T.J.; Tung, C.J.; Yeh, W.W.; Liao, R.Y.

    2004-01-01

    The International Commission on Radiological Protection (ICRP) recommended a system of dose limits for the protection of ionizing radiation. This system was established based on the effective dose, E, and the equivalent dose to an organ or tissue, H T , to assess stochastic and deterministic effects. In radiation protection monitoring for external radiation, operational doses such as the deep dose equivalent index, H I,d , shallow dose equivalent index, H I,s , ambient dose equivalent [1,4-6], H*, directional dose equivalent, H', individual dose equivalent-penetrating, H p , and individual dose equivalent-superficial, H s , are implemented. These quantities are defined in an International Commission on Radiation Units and Measurements (ICRU) sphere and in an anthropomorphic phantom under simplified irradiation conditions. They are useful when equivalent doses are below the corresponding limits. In the case of equivalent doses far below the limits, the exposure or air kerma is commonly applied. For workers exposed to high levels of radiation, accurate assessments of effective doses and equivalent doses may be needed in order to acquire legal and health information. In the general principles of monitoring for radiation protection of workers, ICRP recommended that: 'A graduated response is advocated for the monitoring of the workplace and for individual monitoring - graduated in the sense that a greater degree of monitoring is deemed to be necessary as doses increase of as unpredictability increases. Gradually more complex or realistic procedures should be adopted as doses become higher. Thus, at low dose equivalents (corresponding say to those within Working Condition B) dosimetric quantities might be used directly to assess exposure, since accuracy is not crucial. At intermediate dose equivalents (corresponding say to Working Condition A and slight overexposures) somewhat greater accuracy is warranted, and the conversion coefficients from dosimetric to radiation

  16. Development of Computational Procedure for Assessment of Patient Dose in Multi-Detector Computed Tomography

    International Nuclear Information System (INIS)

    Park, Dong Wook

    2007-02-01

    Technological development to improve the quality and speed with which images are obtained have fostered the growth of frequency and collective effective dose of CT examination. Especially, High-dose x-ray technique of CT has increased in the concern of patient dose. However CTDI and DLP in CT dosimetry leaves something to be desired to evaluate patient dose. And even though the evaluation of effective dose in CT practice is required for comparison with other radiography, it's not sufficient to show any estimation because it's not for medical purpose. Therefore the calculation of effective dose in CT procedure is needed for that purpose. However modelling uncertainties will be due to insufficient information from manufacturing tolerances. Therefore the purpose of this work is development of computational procedure for assessment of patient dose through the experiment for getting essential information in MDCT. In order to obtain exact absorbed dose, normalization factors must be created to relate simulated dose values with CTDI air measurement. The normalization factors applied to the calculation of CTDI 100 using axial scanning and organ effective dose using helical scanning. The calculation of helical scanning was compared with the experiment of Groves et al.(2004). The result has a about factor 2 of the experiment. It seems because AEC is not simulated. In several studies, when AEC applied to a CT examination, approximately 20-30% dose reduction was appeared. Therefore the study of AEC simulation should be added and modified

  17. Atmospheric diffusion and dose estimation for habitability assessments

    International Nuclear Information System (INIS)

    Xing Fuli; Li Xu

    1993-01-01

    The assessment of Emergency Centre has a bearing on the implementing of Emergency plan, and is of great significance. So the calculation procedure and models concerning the normalized concentration (X/Q) in the building wakes are becoming very important. A model which is different from the currently used is used to assess the habitability of Emergency Centre of a certain power plant in China. (4 figs., 3 tabs.)

  18. Review on Population Projection Methodology for Radiological Dose Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Jang, M. S.; Kang, H. S.; Kim, S. R. [NESS, Daejeon (Korea, Republic of); Hwang, W. T. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Yang, Y. H. [KHNP, Daejeon (Korea, Republic of)

    2015-05-15

    Radiation environment report (RER), one of the essential documents in plant operating license or continuous operation license, includes population projection. Population estimates are utilized in determining the collective dose at the operation or restart time of nuclear power plant. Many population projection models are suggested and also under development. We carried out the sensitivity analysis on various population projection models to Daejeon city as a target. Daejeon city showed the increase or decrease in the cross-sectional population, because of the development of Sejong city, Doan new town and etc. We analyzed the population of Daejeon city using statistical ARIMA model and various simple population projection models. It is important to determine the population limit in Modified exponential model but it is not easy. Therefore, the various properties of the area such as the decrease and increase of population, new town development plan, social and natural environment change and etc., should be carefully reviewed to estimate the future population of any area.

  19. Sensitivity analysis of the RESRAD, a dose assessment code

    International Nuclear Information System (INIS)

    Yu, C.; Cheng, J.J.; Zielen, A.J.

    1991-01-01

    The RESRAD code is a pathway analysis code that is designed to calculate radiation doses and derive soil cleanup criteria for the US Department of Energy's environmental restoration and waste management program. the RESRAD code uses various pathway and consumption-rate parameters such as soil properties and food ingestion rates in performing such calculations and derivations. As with any predictive model, the accuracy of the predictions depends on the accuracy of the input parameters. This paper summarizes the results of a sensitivity analysis of RESRAD input parameters. Three methods were used to perform the sensitivity analysis: (1) Gradient Enhanced Software System (GRESS) sensitivity analysis software package developed at oak Ridge National Laboratory; (2) direct perturbation of input parameters; and (3) built-in graphic package that shows parameter sensitivities while the RESRAD code is operational

  20. Review on Population Projection Methodology for Radiological Dose Assessment

    International Nuclear Information System (INIS)

    Jang, M. S.; Kang, H. S.; Kim, S. R.; Hwang, W. T.; Yang, Y. H.

    2015-01-01

    Radiation environment report (RER), one of the essential documents in plant operating license or continuous operation license, includes population projection. Population estimates are utilized in determining the collective dose at the operation or restart time of nuclear power plant. Many population projection models are suggested and also under development. We carried out the sensitivity analysis on various population projection models to Daejeon city as a target. Daejeon city showed the increase or decrease in the cross-sectional population, because of the development of Sejong city, Doan new town and etc. We analyzed the population of Daejeon city using statistical ARIMA model and various simple population projection models. It is important to determine the population limit in Modified exponential model but it is not easy. Therefore, the various properties of the area such as the decrease and increase of population, new town development plan, social and natural environment change and etc., should be carefully reviewed to estimate the future population of any area

  1. Neutron and photon dose assessment in Indus accelerator complex

    International Nuclear Information System (INIS)

    Verma, Dimple; Haridas Nair, G.; Bandopadhyay, Tapas; Tripathy, R.M.; Pal, Rupali; Bakshi, A.K.; Palani Selvam, T.; Datta, D.

    2016-02-01

    Indus Accelerator Complex (IAC) consists of 20 MeV Microtron, 450/550 MeV Booster, 450 MeV Indus-1 and 2.5 GeV Indus-2 storage rings. The radiation environment in Indus Accelerator Complex comprises of bremsstrahlung photons, electrons, positrons, photo neutrons and muons, out of which, bremsstrahlung photons are the major constituent of the prompt radiation. Major problem faced for on-line detection of neutrons is their severely pulsed nature. In the present study, measurement of neutron and photon dose rates in Indus Accelerator Complex was carried out using passive dosimeters such as CR-39 solid state nuclear track detector (SSNTD) and CaSO 4 :Dy Teflon disc, 6 LiF:Mg,Ti (TLD 600) and 7 LiF:Mg,Ti (TLD 700) based thermo luminescent (TL) detectors. The report describes the details of the measurement and discusses the results. (author)

  2. Determination of uranium in soil with emphasis on dose assessment

    International Nuclear Information System (INIS)

    Vidic, A.; Ilic, Z.; Deljkic, D.; Repinc, U.; Benedik, Lj.; Maric, S.

    2005-01-01

    Uranium is present naturally in the earth crust and has three isotopes with long half-lives. These isotopes are 2 38U (99.27% natural abundance), 2 35U (0.72% natural abundance) and 2 34U (0.006% natural abundance). Isotope 2 35U is a valuable fuel for nuclear power plants. During the manufacture of nuclear fuel the concentration of 2 35U is increased. Depleted uranium (DU) is a waste product of this enrichment process and typically contains about 99.8% 2 38U , 0.2% 2 35U and 0.0006% 2 34U in mass. Due to its high density and other physical properties, DU is used in munitions designed to penetrate armour plate. DU weapons were used during the Balkan war in Bosnia and Herzegovina. It was estimated, that nearly 10,000 projectiles were fired or 3 tonnes of DU used in BandH. The aim of this work was to determine uranium radioisotopes in soil and air collected in Hadzici (near Sarajevo). The investigated area is a former military base used for the production and maintenance of tanks and other heavy military vehicles. During a NATO attack in 1995, about 1,500 rounds were fired at the site. The specific activities of 2 38U found in soil ranged from 28 Bq/kg to 55 Bq/kg. We found higher specific activities in some foci, in the range from 143 Bq/kg to 810 Bq/kg. The specific activities of uranium isotopes in the air were determined using simple dust loading approach. The results served to calculate the annual effective dose that could be received by individual workers at the site and by general population from the surrounding area. Radioactivity measurements in the environment of Hadzici showed that the annual effective dose for general population was less than 20 micro Sv.(author)

  3. Unmanned Aerial Vehicle (UAV) data analysis for fertilization dose assessment

    Science.gov (United States)

    Kavvadias, Antonis; Psomiadis, Emmanouil; Chanioti, Maroulio; Tsitouras, Alexandros; Toulios, Leonidas; Dercas, Nicholas

    2017-10-01

    The growth rate monitoring of crops throughout their biological cycle is very important as it contributes to the achievement of a uniformly optimum production, a proper harvest planning, and reliable yield estimation. Fertilizer application often dramatically increases crop yields, but it is necessary to find out which is the ideal amount that has to be applied in the field. Remote sensing collects spatially dense information that may contribute to, or provide feedback about, fertilization management decisions. There is a potential goal to accurately predict the amount of fertilizer needed so as to attain an ideal crop yield without excessive use of fertilizers cause financial loss and negative environmental impacts. The comparison of the reflectance values at different wavelengths, utilizing suitable vegetation indices, is commonly used to determine plant vigor and growth. Unmanned Aerial Vehicles (UAVs) have several advantages; because they can be deployed quickly and repeatedly, they are flexible regarding flying height and timing of missions, and they can obtain very high-resolution imagery. In an experimental crop field in Eleftherio Larissa, Greece, different dose of pre-plant and in-season fertilization was applied in 27 plots. A total of 102 aerial photos in two flights were taken using an Unmanned Aerial Vehicle based on the scheduled fertilization. Α correlation of experimental fertilization with the change of vegetation indices values and with the increase of the vegetation cover rate during those days was made. The results of the analysis provide useful information regarding the vigor and crop growth rate performance of various doses of fertilization.

  4. Fluoroscopic Analysis of Tibial Translation in Anterior Cruciate Ligament Injured Knees With and Without Bracing During Forward Lunge.

    Science.gov (United States)

    Jalali, Maryam; Farahmand, Farzam; Mousavi, Seyed Mohammad Ebrahim; Golestanha, Seyed Ali; Rezaeian, Tahmineh; Shirvani Broujeni, Shahram; Rahgozar, Mehdi; Esfandiarpour, Fateme

    2015-07-01

    Despite several studies with different methods, the effect of functional knee braces on knee joint kinematics is not clear. Direct visualization of joint components through medical imaging modalities may provide the clinicians with more useful information. In this study, for the first time in the literature, video fluoroscopy was used to investigate the effect of knee bracing on the sagittal plane kinematics of anterior cruciate ligament (ACL) injured patients. For twelve male unilateral ACL deficient subjects, the anterior tibial translation was measured during lunge exercise in non-braced and braced conditions. Fluoroscopic images were acquired from the subjects using a digital fluoroscopy system with a rate of 10 fps. The image of each frame was scaled using a calibration coin and analyzed in AutoCAD environment. The angle between the two lines, tangent to the posterior cortexes of the femoral and tibial shafts was measured as the flexion angle. For the fluoroscopic images associated with 0°, 15°, 30°, 45° and 60° knee flexion angles, the relative anterior-posterior configuration of the tibiofemoral joint was assessed by measuring the position of landmarks on the tibia and femur. Results indicated that the overall anterior translations of the tibia during the eccentric (down) and concentric (up) phases of lunge exercise were 10.4 ± 1.7 mm and 9.0 ± 2.2 mm for non-braced, and 10.1 ± 3.4 mm and 7.4 ± 2.5 mm, for braced conditions, respectively. The difference of the tibial anterior-posterior translation behaviors of the braced and non-braced knees was not statistically significant. Fluoroscopic imaging provides an effective tool to measure the dynamic behavior of the knee joint in the sagittal plane and within the limitations of this study, the pure mechanical stabilizing effect of functional knee bracing is not sufficient to control the anterior tibial translation of the ACL deficient patients during lunge exercise.

  5. QUANTITATION OF MOLECULAR ENDPOINTS FOR THE DOSE-RESPONSE COMPONENT OF CANCER RISK ASSESSMENT

    Science.gov (United States)

    Cancer risk assessment involves the steps of hazard identification, dose-response assessment, exposure assessment and risk characterization. The rapid advances in the use of molecular biology approaches has had an impact on all four components, but the greatest overall current...

  6. Non-monotonic dose-response relationships and endocrine disruptors: a qualitative method of assessment

    OpenAIRE

    Lagarde, Fabien; Beausoleil, Claire; Belcher, Scott M; Belzunces, Luc P; Emond, Claude; Guerbet, Michel; Rousselle, Christophe

    2015-01-01

    International audience; Experimental studies investigating the effects of endocrine disruptors frequently identify potential unconventional dose-response relationships called non-monotonic dose-response (NMDR) relationships. Standardized approaches for investigating NMDR relationships in a risk assessment context are missing. The aim of this work was to develop criteria for assessing the strength of NMDR relationships. A literature search was conducted to identify published studies that repor...

  7. Assessment of skin dose modification caused by application of immobilizing cast in head and neck radiotherapy

    International Nuclear Information System (INIS)

    Soleymanifard, Shokouhozaman; Toossi, Mohammad T.B.; Khosroabadi, Mohsen; Noghreiyan, Atefeh Vejdani; Shahidsales, Soodabeh; Tabrizi, Fatemeh Varshoee

    2014-01-01

    Skin dose assessment for radiotherapy patients is important to ensure that the dose received by skin is not excessive and does not cause skin reactions. Immobilizing casts may have a buildup effect, and can enhance the skin dose. This study has quantified changes to the surface dose as a result of head and neck immobilizing casts. Medtech and Renfu casts were stretched on the head of an Alderson Rando-Phantom. Irradiation was performed using 6 and 15 MV X-rays, and surface dose was measured by thermoluminescence dosimeters. In the case of 15MV photons, immobilizing casts had no effect on the surface dose. However, the mean surface dose increase reached up to 20 % when 6MV X-rays were applied. Radiation incidence angle, thickness, and meshed pattern of the casts affected the quantity of dose enhancement. For vertical beams, the surface dose increase was more than tangential beams, and when doses of the points under different areas of the casts were analysed separately, results showed that only doses of the points under the thick area had been changed. Doses of the points under the thin area and those within the holes were identical to the same points without immobilizing casts. Higher dose which was incurred due to application of immobilizing casts (20 %) would not affect the quality of life and treatment of patients whose head and neck are treated. Therefore, the benefits of head and neck thermoplastic casts are more than their detriments. However, producing thinner casts with larger holes may reduce the dose enhancement effect.

  8. The assessment of the collective dose for China population travelling by water

    International Nuclear Information System (INIS)

    Yue Qingyu; Jiang Ping; Jin Hua

    1992-01-01

    The exposure dose rate at 212 points in six shipping lines of the inshore and inland rivers has been measured and the average natural sources exposure dose rate which may be received by the travellers in each shipping line has got. The assessment of collective dose equivalent for the travellers on the shipping lines and the fishery people on the sea has done. In 1988, the collective dose equivalent from natural sources received by Chinese population travelled on the shipping lines of the inshore and inland rivers was 32.7 man·Sv, and the collective dose equivalent from natural sources received by fishery people on the sea was 265.3 man·Sv. The average dose equivalent rate from natural sources at various stayed point received by people of China is given

  9. A new method to assess the gonadal doses in women during radiation treatment

    International Nuclear Information System (INIS)

    Agrawal, M.S.; Pant, G.C.

    1977-01-01

    The relative inaccessibility of the ovaries renders direct measurement of the gonadal doses difficult. A relatively simple method is described to tackle this problem - using the upper margin of the public symphysis as a reference point. Measurement of Radiation doses were done in a Masonite human phantom using T.L.D. and a Co-60 teletherapy unit. The accompanying figures document the observations made. The distance between the lower edge of the treatment port and the reference point is denoted by 'd'. First figure relates observed ratios of the radiation doses at the ovary and the reference point to 'd' for various port sizes and the second figure shows the relationship between the area of the port and the dose ratio (ovary: reference-point) for various values of 'd'. The advantage of this documentation is that it serves as a 'Ready Reckoner' to assess the ovarian doses under different treatment situations-once the doses at the reference point is measured

  10. Feasibility study for the assessment of the exposed dose with TENORM added in consumer products

    International Nuclear Information System (INIS)

    Yoo, Do Hyeon; Lee, Hyun Cheol; Shin, Wook-Geun; Min, Chul Hee; Ha, Wi-Ho; Yoo, Jae Ryong; Yoon, Seok-Won; Lee, Jiyon; Choi, Won-Chul

    2015-01-01

    Consumer products including naturally occurring radioactive material have been distributed widely in human life. The potential hazard of the excessively added technically enhanced naturally occurring radioactive material (TENORM) in consumer products should be assessed. The aim of this study is to evaluate the organ equivalent dose and the annual effective dose with the usage of the TENORM added in paints. The activities of gammas emitted from natural radionuclides in the five types of paints were measured with the high-purity germanium detector, and the annual effective dose was assessed with the computational human phantom and the Monte Carlo method. The results show that uranium and thorium series were mainly measured over the five paints. Based on the exposure scenario of the paints in the room, the highest effective dose was evaluated as <1 mSv y -1 of the public dose limit. (authors)

  11. Assessment of coverage levels of single dose measles vaccine

    International Nuclear Information System (INIS)

    Tariq, P.

    2003-01-01

    Objective: To study the consequences of low coverage levels of a single dose of measles vaccine. Results: mean age observed in measles cases was 2 years and 8 months with a range from 3 months to 8 years. Maximum number of cases reported were <1 year of age (n=22,32%). Fifty percent of cases were seen among vaccinated children. Seventy-five percent (n=51) had history of contact with a measles case. Pneumonia was the commonest complication followed by acute gastroenteritis, encephalitis, febrile convulsions, oral ulcers, oral thrush, eye changes of vitamin-A deficiency and pulmonary tuberculosis (T.B.) in descending order of frequency. Fifty four cases were successfully treated for complications of measles and discharged. Nine cases left against medical advice. Five patients died all of them had encephalitis either alone (n=1) or in combination with pneumonia and acute gastroenteritis (n=4). Conclusion: There is a dire need to increase the immunization coverage to reduce the rate of vaccine failure and achieve effective control of measles.(author)

  12. Is lead shielding of patients necessary during fluoroscopic procedures? A study based on kyphoplasty

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Joshua R.; Marsh, Rebecca M.; Silosky, Michael S. [University of Colorado School of Medicine, Department of Radiology, Aurora, CO (United States)

    2018-01-15

    To determine the benefits, risks, and limitations associated with wrapping a patient with lead shielding during fluoroscopy-guided kyphoplasty procedures as a way to reduce operator radiation exposure. An anthropomorphic phantom was used to mimic a patient undergoing a kyphoplasty procedure under fluoroscopic guidance. Radiation measurements of the air kerma rate (AKR) were made at several locations and under various experimental conditions. First, AKR was measured at various angles along the horizontal plane of the phantom and at varying distances from the phantom, both with and without a lead apron wrapped around the lower portion of the phantom (referred to here as phantom shielding). Second, the effect of an operator's apron was simulated by suspending a lead apron between the phantom and the measurement device. AKR was measured for the four shielding conditions - phantom shielding only, operator apron only, both phantom shielding and operator apron, and no shielding. Third, AKR measurements were made at various heights and with varying C-arm angle. At all locations, the phantom shielding provided no substantial protection beyond that provided by an operator's own lead apron. Phantom shielding did not reduce AKR at a height comparable to that of an operator's head. Previous reports of using patient shielding to reduce operator exposure fail to consider the role of an operator's own lead apron in radiation protection. For an operator wearing appropriate personal lead apparel, patient shielding provides no substantial reduction in operator dose. (orig.)

  13. Is lead shielding of patients necessary during fluoroscopic procedures? A study based on kyphoplasty

    International Nuclear Information System (INIS)

    Smith, Joshua R.; Marsh, Rebecca M.; Silosky, Michael S.

    2018-01-01

    To determine the benefits, risks, and limitations associated with wrapping a patient with lead shielding during fluoroscopy-guided kyphoplasty procedures as a way to reduce operator radiation exposure. An anthropomorphic phantom was used to mimic a patient undergoing a kyphoplasty procedure under fluoroscopic guidance. Radiation measurements of the air kerma rate (AKR) were made at several locations and under various experimental conditions. First, AKR was measured at various angles along the horizontal plane of the phantom and at varying distances from the phantom, both with and without a lead apron wrapped around the lower portion of the phantom (referred to here as phantom shielding). Second, the effect of an operator's apron was simulated by suspending a lead apron between the phantom and the measurement device. AKR was measured for the four shielding conditions - phantom shielding only, operator apron only, both phantom shielding and operator apron, and no shielding. Third, AKR measurements were made at various heights and with varying C-arm angle. At all locations, the phantom shielding provided no substantial protection beyond that provided by an operator's own lead apron. Phantom shielding did not reduce AKR at a height comparable to that of an operator's head. Previous reports of using patient shielding to reduce operator exposure fail to consider the role of an operator's own lead apron in radiation protection. For an operator wearing appropriate personal lead apparel, patient shielding provides no substantial reduction in operator dose. (orig.)

  14. Robust fluoroscopic tracking of fiducial markers: exploiting the spatial constraints

    International Nuclear Information System (INIS)

    Li Rui; Sharp, Gregory

    2013-01-01

    Two new fluoroscopic fiducial tracking methods that exploit the spatial relationship among the multiple implanted fiducial to achieve fast, accurate and robust tracking are proposed in this paper. The spatial relationship between multiple implanted markers are modeled as Gaussian distributions of their pairwise distances over time. The means and standard deviations of these distances are learned from training sequences, and pairwise distances that deviate from these learned distributions are assigned a low spatial matching score. The spatial constraints are incorporated in two different algorithms: a stochastic tracking method and a detection based method. In the stochastic method, hypotheses of the ‘true’ fiducial position are sampled from a pre-trained respiration motion model. Each hypothesis is assigned an importance value based on image matching score and spatial matching score. Learning the parameters of the motion model is needed in addition to learning the distribution parameters of the pairwise distances in the proposed stochastic tracking approach. In the detection based method, a set of possible marker locations are identified by using a template matching based fiducial detector. The best location is obtained by optimizing the image matching score and spatial matching score through non-serial dynamic programming. In this detection based approach, there is no need to learn the respiration motion model. The two proposed algorithms are compared with a recent work using a multiple hypothesis tracking (MHT) algorithm which is denoted by MHT, Tang et al (2007 Phys. Med. Biol. 52 4081–98). Phantom experiments were performed using fluoroscopic videos captured with known motion relative to an anthropomorphic phantom. The patient experiments were performed using a retrospective study of 16 fluoroscopic videos of liver cancer patients with implanted fiducials. For the motion phantom data sets, the detection based approach has the smallest tracking error (

  15. Assessment of female breast dose for thoracic cone-beam CT using MOSFET dosimeters.

    Science.gov (United States)

    Sun, Wenzhao; Wang, Bin; Qiu, Bo; Liang, Jian; Xie, Weihao; Deng, Xiaowu; Qi, Zhenyu

    2017-03-21

    To assess the breast dose during a routine thoracic cone-beam CT (CBCT) check with the efforts to explore the possible dose reduction strategy. Metal oxide semiconductor field-effect transistor (MOSFET) dosimeters were used to measure breast surface doses during a thorax kV CBCT scan in an anthropomorphic phantom. Breast doses for different scanning protocols and breast sizes were compared. Dose reduction was attempted by using partial arc CBCT scan with bowtie filter. The impact of this dose reduction strategy on image registration accuracy was investigated. The average breast surface doses were 20.02 mGy and 11.65 mGy for thoracic CBCT without filtration and with filtration, respectively. This indicates a dose reduction of 41.8% by use of bowtie filter. It was found 220° partial arc scanning significantly reduced the dose to contralateral breast (44.4% lower than ipsilateral breast), while the image registration accuracy was not compromised. Breast dose reduction can be achieved by using ipsilateral 220° partial arc scan with bowtie filter. This strategy also provides sufficient image quality for thorax image registration in daily patient positioning verification.

  16. Development on Dose Assessment Model of Northeast Asia Nuclear Accident Simulator

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ju Yub; Kim, Ju Youl; Kim, Suk Hoon; Lee, Seung Hee; Yoon, Tae Bin [FNC Techology, Yongin (Korea, Republic of)

    2016-05-15

    In order to support the emergency response system, the simulator for overseas nuclear accident is under development including source-term estimation, atmospheric dispersion modeling and dose assessment. The simulator is named NANAS (Northeast Asia Nuclear Accident Simulator). For the source-term estimation, design characteristics of each reactor type should be reflected into the model. Since there are a lot of reactor types in neighboring countries, the representative reactors of China, Japan and Taiwan have been selected and the source-term estimation models for each reactor have been developed, respectively. For the atmospheric dispersion modeling, Lagrangian particle model will be integrated into the simulator for the long range dispersion modeling in Northeast Asia region. In this study, the dose assessment model has been developed considering external and internal exposure. The dose assessment model has been developed as a part of the overseas nuclear accidents simulator which is named NANAS. It addresses external and internal pathways including cloudshine, groundshine and inhalation. Also, it uses the output of atmospheric dispersion model (i.e. the average concentrations of radionuclides in air and ground) and various coefficients (e.g. dose conversion factor and breathing rate) as an input. Effective dose and thyroid dose for each grid in the Korean Peninsula region are printed out as a format of map projection and chart. Verification and validation on the dose assessment model will be conducted in further study by benchmarking with the measured data of Fukushima Daiichi Nuclear Accident.

  17. Assessment of inhalation dose sensitivity by physicochemical properties of airborne particulates containing naturally occurring radioactive materials

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Si Young; Choi, Cheol Kyu; Kim, Yong Geon; Choi, Won Chul; Kim, Kwang Pyo [Kyung Hee University, Seoul (Korea, Republic of)

    2015-12-15

    Facilities processing raw materials containing naturally occurring radioactive materials (NORM) may give rise to enhanced radiation dose to workers due to chronic inhalation of airborne particulates. Internal radiation dose due to particulate inhalation varies depending on particulate properties, including size, shape, density, and absorption type. The objective of the present study was to assess inhalation dose sensitivity to physicochemical properties of airborne particulates. Committed effective doses to workers resulting from inhalation of airborne particulates were calculated based on International Commission on Radiological Protection 66 human respiratory tract model. Inhalation dose generally increased with decreasing particulate size. Committed effective doses due to inhalation of 0.01μm sized particulates were higher than doses due to 100μm sized particulates by factors of about 100 and 50 for {sup 238}U and {sup 230}Th, respectively. Inhalation dose increased with decreasing shape factor. Shape factors of 1 and 2 resulted in dose difference by about 18 %. Inhalation dose increased with particulate mass density. Particulate mass densities of 11 g·cm{sup -3} and 0.7 g·cm{sup -3} resulted in dose difference by about 60 %. For {sup 238}U, inhalation doses were higher for absorption type of S, M, and F in that sequence. Committed effective dose for absorption type S of {sup 238}U was about 9 times higher than dose for absorption F. For {sup 230}Th, inhalation doses were higher for absorption type of F, M, and S in that sequence. Committed effective dose for absorption type F of {sup 230}Th was about 16 times higher than dose for absorption S. Consequently, use of default values for particulate properties without consideration of site specific physiochemical properties may potentially skew radiation dose estimates to unrealistic values up to 1-2 orders of magnitude. For this reason, it is highly recommended to consider site specific working materials and

  18. Role of fluoroscopic guided self expandable metallic stents in the management of malignant esophageal strictures

    OpenAIRE

    Mohamed Shaker; Ahmed Deif; Amr Abdelaal

    2016-01-01

    Objectives: To evaluate the role of fluoroscopic guided self expanding metallic stents in the management of dysphagia caused by malignant esophageal strictures. Materials and methods: During the period between April 2010 and October 2012, 31 patients with malignant esophageal strictures were subjected to fluoroscopic guided self expanding metallic stent application. The study included 22 males and 9 females ranging in age between 22 and 75 years old with mean age of 56.8 years. Lesions wer...

  19. A geographical basis for long-range dose assessment calculations

    International Nuclear Information System (INIS)

    Walker, H.; Hage, G.

    1989-01-01

    Releases of radioactive material into the atmosphere have effects that are distributed over the earth's surface. As a result, geographical information can play an important role in understanding the impact of an emergency. The Atmospheric Release Advisory Capability (ARAC) at Lawrence Livermore National Laboratory is an emergency response organization that utilizes complex computer models to provide real-time assessments of the consequences of such releases. These models are one component of a sophisticated system that also includes data-gathering systems, data analysis techniques, and highly trained operational personnel. The products of this service are isopleths of the material concentration plotted over a base map of geographic features. The components mentioned in this paper are being added to the operation ARAC system. This will provide a means of producing fast, high-quality assessments of the consequences of major releases of radioactive material with effects extending to continental and global regions

  20. GEMA3D - landscape modelling for dose assessments

    International Nuclear Information System (INIS)

    Klos, Richard

    2010-08-01

    Concerns have been raised about SKB's interpretation of landscape objects in their radiological assessment models, specifically in relation to the size of the objects represented - leading to excessive volumetric dilution - and to the interpretation of local hydrology - leading to non-conservative hydrologic dilution. Developed from the Generic Ecosystem Modelling Approach, GEMA3D is an attempt to address these issues in a simple radiological assessment landscape model. In GEMA3D landscape features are model led as landscape elements (lels) based on a three compartment structure which is able to represent both terrestrial and aquatic lels. The area of the lels can be chosen to coincide with the bedrock fracture from which radionuclides are assumed to be released and the dispersion of radionuclides through out the landscape can be traced. Result indicate that released contaminants remain localised close to the release location and follow the main flow axis of the surface drainage system. This is true even for relatively weakly sorbing species. An interpretation of the size of landscape elements suitable to represent dilution in the biosphere for radiological assessment purposes is suggested, though the concept remains flexible. For reference purposes an agricultural area of one hectare is the baseline. The Quaternary deposits (QD) at the Forsmark site are only a few metres thick above the crystalline bedrock in which the planned repository for spent fuel will be constructed. The biosphere model is assumed to be the upper one metre of the QD. A further model has been implemented for advective - dispersive transport in the deeper QD. The effects of chemical zonation have been briefly investigated. The results confirm the importance of retention close to the release point from the bedrock and clearly indicate that there is a need for a better description of the hydrology of the QD on the spatial scales relevant to the lels required for radiological assessments

  1. GEMA3D - landscape modelling for dose assessments

    Energy Technology Data Exchange (ETDEWEB)

    Klos, Richard (Aleksandria Sciences (United Kingdom))

    2010-08-15

    Concerns have been raised about SKB's interpretation of landscape objects in their radiological assessment models, specifically in relation to the size of the objects represented - leading to excessive volumetric dilution - and to the interpretation of local hydrology - leading to non-conservative hydrologic dilution. Developed from the Generic Ecosystem Modelling Approach, GEMA3D is an attempt to address these issues in a simple radiological assessment landscape model. In GEMA3D landscape features are model led as landscape elements (lels) based on a three compartment structure which is able to represent both terrestrial and aquatic lels. The area of the lels can be chosen to coincide with the bedrock fracture from which radionuclides are assumed to be released and the dispersion of radionuclides through out the landscape can be traced. Result indicate that released contaminants remain localised close to the release location and follow the main flow axis of the surface drainage system. This is true even for relatively weakly sorbing species. An interpretation of the size of landscape elements suitable to represent dilution in the biosphere for radiological assessment purposes is suggested, though the concept remains flexible. For reference purposes an agricultural area of one hectare is the baseline. The Quaternary deposits (QD) at the Forsmark site are only a few metres thick above the crystalline bedrock in which the planned repository for spent fuel will be constructed. The biosphere model is assumed to be the upper one metre of the QD. A further model has been implemented for advective - dispersive transport in the deeper QD. The effects of chemical zonation have been briefly investigated. The results confirm the importance of retention close to the release point from the bedrock and clearly indicate that there is a need for a better description of the hydrology of the QD on the spatial scales relevant to the lels required for radiological assessments

  2. Assessment of adequacy of hemodialysis dose at a Palestinian hospital

    Directory of Open Access Journals (Sweden)

    Heba Adas

    2014-01-01

    Full Text Available Adequacy of hemodialysis improves patient survival, quality of life and biochemical outcomes and minimizes disease complications and hospitalizations. This study was an observational cross-sectional study that was conducted in July 2012. Blood tests, weight and blood pressure were measured before and after hemodialysis. Single-pool Kt/V and urea reduction ratio (URR were calculated. The targets based on the National Kidney Foundation Disease Outcomes Quality Initiative (KDOQI Clinical Practice Guidelines were Kt/V ≥ 1.2 and URR ≥ 65%. Of the 64 patients, 41 (64.1% were males. The mean age of the patients was 58.13 ± 17.2 years. The mean body mass index (BMI was 25.04 ± 5.01 kg/m 2 . The mean Kt/V and URR were 1.06 ± 0.05 and 54.4 ± 19.3, respectively. There was no significant difference between men and women (1.06 ± 0.47 versus 1.04 ± 0.55, P = 0.863 and (54.7 ± 19.59 versus 53.81 ± 19.17, P = 0.296. Only 25 (39.1% patients achieved the Kt/V goal and only 22 (34.4% had target URR, and there was no significant association between hemodialysis adequacy and any of the variables such as sex, age, presence of chronic diseases or BMI. Serum potassium levels post-dialysis were significantly lower in patients who reached the target Kt/V (mean = 3.44 ± 0.48 versus 3.88 ± 0.48, P = 0.001. Most patients were inadequately dialyzed and a large percentage of the patients did not attain the targets. Attempts to achieve the desired goals are necessary. It is important to calculate Kt/V or URR and individualize the dialysis doses for each patient.

  3. Radiation doses of patients and urologists during percutaneous nephrolithotomy

    Energy Technology Data Exchange (ETDEWEB)

    Safak, M; Gogus, C [Faculty of Medicine, Ibni Sina Hospital, Department of Urology, Ankara University, 06450 Samanpazari, Ankara (Turkey); Olgar, T; Bor, D; Berkmen, G [Faculty of Engineering, Department of Physics Engineering, Ankara University, 06100, Tandogan, Ankara (Turkey)], E-mail: olgar@eng.ankara.edu.tr

    2009-09-01

    Renal stones can be treated either by extracorporeal shock wave lithotripsy (ESWL) or percutaneous nephrolithotomy (PCNL). Increasing use of fluoroscopic exposure for access and to detect stone location during PCNL make the measurement of patient and staff doses important. The main objective of this work was to assess patient and urologist doses for the PCNL examination. We used the tube output technique for determination of patient doses (n = 20) and lithium fluoride thermoluminescent dosimeter (TLD) chips for urologist dose measurements. The TLD technique was also used for some patient dose measurements (n = 7) for comparison with the tube output technique. Mean entrance skin doses of 191 and 117 mGy were measured by the tube output technique for anterior-posterior (AP) and right anterior oblique (RAO) 30 deg./left anterior oblique (LAO) 30 deg. projections, respectively. The mean urologist doses for eye, finger and collar were measured as 26, 33.5 and 48 {mu}Gy per procedure, respectively. The mean effective dose per procedure for the urologist was 12.7 {mu}Sv. None of the individual skin dose results approach deterministic levels.

  4. Radiation doses of patients and urologists during percutaneous nephrolithotomy

    International Nuclear Information System (INIS)

    Safak, M; Gogus, C; Olgar, T; Bor, D; Berkmen, G

    2009-01-01

    Renal stones can be treated either by extracorporeal shock wave lithotripsy (ESWL) or percutaneous nephrolithotomy (PCNL). Increasing use of fluoroscopic exposure for access and to detect stone location during PCNL make the measurement of patient and staff doses important. The main objective of this work was to assess patient and urologist doses for the PCNL examination. We used the tube output technique for determination of patient doses (n = 20) and lithium fluoride thermoluminescent dosimeter (TLD) chips for urologist dose measurements. The TLD technique was also used for some patient dose measurements (n = 7) for comparison with the tube output technique. Mean entrance skin doses of 191 and 117 mGy were measured by the tube output technique for anterior-posterior (AP) and right anterior oblique (RAO) 30 deg./left anterior oblique (LAO) 30 deg. projections, respectively. The mean urologist doses for eye, finger and collar were measured as 26, 33.5 and 48 μGy per procedure, respectively. The mean effective dose per procedure for the urologist was 12.7 μSv. None of the individual skin dose results approach deterministic levels.

  5. ANDROS: A code for Assessment of Nuclide Doses and Risks with Option Selection

    International Nuclear Information System (INIS)

    Begovich, C.L.; Sjoreen, A.L.; Ohr, S.Y.; Chester, R.O.

    1986-11-01

    ANDROS (Assessment of Nuclide Doses and Risks with Option Selection) is a computer code written to compute doses and health effects from atmospheric releases of radionuclides. ANDROS has been designed as an integral part of the CRRIS (Computerized Radiological Risk Investigation System). ANDROS reads air concentrations and environmental concentrations of radionuclides to produce tables of specified doses and health effects to selected organs via selected pathways (e.g., ingestion or air immersion). The calculation may be done for an individual at a specific location or for the population of the whole assessment grid. The user may request tables of specific effects for every assessment grid location. Along with the radionuclide concentrations, the code requires radionuclide decay data, dose and risk factors, and location-specific data, all of which are available within the CRRIS. This document is a user manual for ANDROS and presents the methodology used in this code

  6. Assessment of eye lens doses for workers during interventional radiology procedures

    International Nuclear Information System (INIS)

    Urboniene, A.; Sadzeviciene, E.; Ziliukas, J.

    2015-01-01

    The assessment of eye lens doses for workers during interventional radiology (IR) procedures was performed using a new eye lens dosemeter. In parallel, the results of routine individual monitoring were analysed and compared with the results obtained from measurements with a new eye lens dosemeter. The eye lens doses were assessed using H p (3) measured at the level of the eyes and were compared with H p (10) measured with the whole-body dosemeter above the lead collar. The information about use of protective measures, the number of performed interventional procedures per month and their fluoroscopy time was also collected. The assessment of doses to the lens of the eye was done for 50 IR workers at 9 Lithuanian hospitals for the period of 2012-2013. If the use of lead glasses is not taken into account, the estimated maximum annual dose equivalent to the lens of the eye was 82 mSv. (authors)

  7. Development of environmental dose assessment system (EDAS) code of PC version

    CERN Document Server

    Taki, M; Kobayashi, H; Yamaguchi, T

    2003-01-01

    A computer code (EDAS) was developed to assess the public dose for the safety assessment to get the license of nuclear reactor operation. This code system is used for the safety analysis of public around the nuclear reactor in normal operation and severe accident. This code was revised and composed for personal computer user according to the Nuclear Safety Guidelines reflected the ICRP1990 recommendation. These guidelines are revised by Nuclear Safety Commission on March, 2001, which are 'Weather analysis guideline for the safety assessment of nuclear power reactor', 'Public dose around the facility assessment guideline corresponding to the objective value for nuclear power light water reactor' and 'Public dose assessment guideline for safety review of nuclear power light water reactor'. This code has been already opened for public user by JAERI, and English version code and user manual are also prepared. This English version code is helpful for international cooperation concerning the nuclear safety assessme...

  8. TU-H-CAMPUS-JeP3-02: Automated Dose Accumulation and Dose Accuracy Assessment for Online Or Offline Adaptive Replanning

    International Nuclear Information System (INIS)

    Chen, G; Ahunbay, E; Li, X

    2016-01-01

    Purpose: With introduction of high-quality treatment imaging during radiation therapy (RT) delivery, e.g., MR-Linac, adaptive replanning of either online or offline becomes appealing. Dose accumulation of delivered fractions, a prerequisite for the adaptive replanning, can be cumbersome and inaccurate. The purpose of this work is to develop an automated process to accumulate daily doses and to assess the dose accumulation accuracy voxel-by-voxel for adaptive replanning. Methods: The process includes the following main steps: 1) reconstructing daily dose for each delivered fraction with a treatment planning system (Monaco, Elekta) based on the daily images using machine delivery log file and considering patient repositioning if applicable, 2) overlaying the daily dose to the planning image based on deformable image registering (DIR) (ADMIRE, Elekta), 3) assessing voxel dose deformation accuracy based on deformation field using predetermined criteria, and 4) outputting accumulated dose and dose-accuracy volume histograms and parameters. Daily CTs acquired using a CT-on-rails during routine CT-guided RT for sample patients with head and neck and prostate cancers were used to test the process. Results: Daily and accumulated doses (dose-volume histograms, etc) along with their accuracies (dose-accuracy volume histogram) can be robustly generated using the proposed process. The test data for a head and neck cancer case shows that the gross tumor volume decreased by 20% towards the end of treatment course, and the parotid gland mean dose increased by 10%. Such information would trigger adaptive replanning for the subsequent fractions. The voxel-based accuracy in the accumulated dose showed that errors in accumulated dose near rigid structures were small. Conclusion: A procedure as well as necessary tools to automatically accumulate daily dose and assess dose accumulation accuracy is developed and is useful for adaptive replanning. Partially supported by Elekta, Inc.

  9. Distribution of radionuclides in potato tubers. Implication for dose assessments

    International Nuclear Information System (INIS)

    Green, N.; Wilkins, B.T.; Poultney, S.

    1997-01-01

    A study of the distribution of 137 Cs, 90 Sr, Pu and Am in potato tubers has been carried out. Cesium-137 was essentially uniformly distributed throughout the tuber, whereas up to about 50% of the 90 Sr activity was found in the peel. Results for actinides indicated that most of the activity would be found in the peel and of this more than half would be located in the thin outermost skin. When account is taken of the form in which potatoes are consumed in the UK, the values of soil-plant transfer factors currently assumed in the NRPB model FARMLAND are reasonable for general assessment purposes. (author)

  10. OSL signal of IC chips from mobile phones for dose assessment in accidental dosimetry

    International Nuclear Information System (INIS)

    Mrozik, A.; Marczewska, B.; Bilski, P.; Książek, M.

    2017-01-01

    The rapid assessment of the radiation dose is very important for the prediction of biological effects after unintended exposition. The materials for use as dosimeters in accidental dosimetry should be everyday objects which are usually placed near the human body, for example mobile phones. IC (Integrated Circuit) chip is one of several electronic components of mobile phones which give a luminescent signal. The measurements of samples from different mobile phones and smartphones were conducted by optically stimulated luminescence (OSL) and thermoluminescence (TL) methods. The OSL measurement was performed in two ways: with readouts at room temperature and at 100 °C. This work is focused on determination of OSL dose response of IC chips, minimum detectable dose (MDD), OSL signal stability in the time after the exposition, its repeatability and sensitivity to light. Several tests of the assessment of unknown doses were also conducted. The readouts at 100 °C indicate the reducing of the fading of OSL signal in the first hours after irradiation in comparison with room temperature readouts. The obtained results showed relatively good dosimetric properties of IC chips: their high sensitivity to the ionizing radiation, linear dose response up to 10 Gy and a good reproducibility of OSL signal which can allow the dose recovery of doses less than 2 Gy in 14 days after an incident with the accuracy better than 25%. The fading is a drawback of IC chips and the fading factor should be considered when calculating the dose. - Highlights: • IC chips from smartphones demonstrated high potential for accidental dosimetry. • Minimum detectable dose was estimated as a value of 50 mGy. • Samples showed linear dose response for the dose range from 0.05 Gy up to 10 Gy.

  11. Application of the ELDO approach to assess cumulative eye lens doses for interventional cardiologists

    International Nuclear Information System (INIS)

    Farah, J.; Jacob, S.; Clairand, I.; Struelens, L.; Vanhavere, F.; Auvinen, A.; Koukorava, C.; Schnelzer, M.

    2015-01-01

    In preparation of a large European epidemiological study on the relation between eye lens dose and the occurrence of lens opacities, the European ELDO project focused on the development of practical methods to estimate retrospectively cumulative eye lens dose for interventional medical professionals exposed to radiation. The present paper applies one of the ELDO approaches, correlating eye lens dose to whole-body doses, to assess cumulative eye lens dose for 14 different Finnish interventional cardiologists for whom annual whole-body dose records were available for their entire working period. The estimated cumulative left and right eye lens dose ranged from 8 to 264 mSv and 6 to 225 mSv, respectively. In addition, calculations showed annual eye lens doses sometimes exceeding the new ICRP annual limit of 20 mSv. The work also highlights the large uncertainties associated with the application of such an approach proving the need for dedicated dosimetry systems in the routine monitoring of the eye lens dose. (authors)

  12. Evaluation of doses in gastrointestinal fluoroscopy

    International Nuclear Information System (INIS)

    Canevaro, Lucia Viviana

    1995-04-01

    This work aims at the development of a methodology to measure radiation doses to patients and professionals (radiologists) in fluoroscopic gastrointestinal tract examinations. Also, it aims at the assessment of the performance of this type of medical x-ray equipment, from the radiation protection point of view at the Department of Radiology of the Hospital Universitario Clementino Fraga Filho (Universidade Federal de Rio de Janeiro). This work was developed in order to identify the actual status and to set base lines as a reference for a quality control program. The calibration procedures of thermoluminescent dosimeters for radiodiagnosis quality beams are discussed and described here as well as its application in dose measurements, for patients and radiologists. The performance of two types of x-ray equipment (fluorescent screen and image intensifier) usually used to perform this examinations was evaluated through appropriate tests. Radiation protection features are also considered. Dose to radiologists at unprotected regions and to patients at several sample points were measured. A comparison of the measured doses given by both types of equipment was made. After further analysis, the necessity to look for methods that reduce unnecessary doses became evident. The high values obtained in some procedures using fluorescent screen make the use of this type of equipment unacceptable. With these results, we consider that Health Care authorities have the responsibility of replacing all fluorescent screen equipment and of establishing standards, and raising awareness the responsible staff. (author)

  13. Assessment of mean glandular dose to patients from digital mammography systems

    International Nuclear Information System (INIS)

    Pwamang, Caroline K.

    2016-07-01

    Mean glandular dose assessment of patients undergoing digital mammography examination has been done. A total of 297 patient data was used for the study. Basic Quality Control tests were done to ascertain the performance of the equipment used. The results of Quality Control tests indicated that the three Mammography units used for this study were functioning within the internationally acceptable performance criteria. Patients with a breast thickness of 30 mm within the two age groups of 40-49 yrs and 50-64 yrs received doses slightly higher than the acceptable dose levels. A patient in the category 40-49 yrs with breast thickness of 30 mm received 1.83 mGy as calculated Mean Glandular Dose, 2.10 mGy was the recorded dose and 1.58 mGy was recorded under the age group 50-64 yrs. These values have deviated by -22%, -40%, and -5.33% respectively from 1.5 mGy which is the recommended dose for a breast thickness of 30 mm. Also patients with breast thickness of 70 mm under the age group 40–49 yrs had a recorded dose of 6.58 mGy, which deviated by -1.21% from the recommended value of 6.5 mGy for that breast thickness. Aside these values, all the other values were within the recommended dose values. The percentage deviation between the recommended values and the calculated values was within ±25% which was a working limit that was set for this work. Doses delivered by the Full-field Digital mammography equipment were higher than doses delivered by the Computered Radiography equipment. The calculated Mean Glandular Doses for the three facilities were within recommended dose values. (author)

  14. Long Term assessment of the dose registered by the Sanitary workers of a mutual

    International Nuclear Information System (INIS)

    Anies Escartin, J.; Perramon Llado, A.

    2004-01-01

    The analysis of a long time period of time (about 17 years) of the professional exposure to ionising radiation of the workers of an accidents Mutual, that has its own personal Dosimetry Service, allows to establish a relation between the showed global reduction of the registered doses of the people exposed and the circumstances and actions that did it possible. The fact to carry out a dosimetric control is an essential factor directed to accomplish the objective of holding the doses as low as achievable, joined with the fact of passing more strict law. Those factors that fixed a reduction of the doses inherited by the sanitary exposed workers whose relation are demonstrated in this study. The collective dose inherited by the bunch of people exposed is the parameter suitable to measure and assess the time history at medium and long term of the exposure conditions of the workers, and identify the more relevant characteristics of the risk by ionising radiation at workplace. The conclusion of the time history analysis of the quantity shows that the total collective dose for more than a thousand people group, are strongly affected by the doses corresponding to less than a 1,5 % of the users. The number of people that have a value dose higher that the average, and the high value of the dose in some periods because of their activity lead to changes of the value of the collective doses that can be higher than 100%. This great uncertainty in the measured value needs more than ten months of control to guarantee the lowering of doses received. The decreasing doses observed are strongly related with the reduction of this relative short number of cases with incidences in the doses registered. An important part of the work is related to identifying the incidences registered, noticing the evolution and checking the most suitable actions to lower it. (Author) 4 refs

  15. Integrated numerical platforms for environmental dose assessments of large tritium inventory facilities

    International Nuclear Information System (INIS)

    Castro, P.; Ardao, J.; Velarde, M.; Sedano, L.; Xiberta, J.

    2013-01-01

    Related with a prospected new scenario of large inventory tritium facilities [KATRIN at TLK, CANDUs, ITER, EAST, other coming] the prescribed dosimetric limits by ICRP-60 for tritium committed-doses are under discussion requiring, in parallel, to surmount the highly conservative assessments by increasing the refinement of dosimetric-assessments in many aspects. Precise Lagrangian-computations of dosimetric cloud-evolution after standardized (normal/incidental/SBO) tritium cloud emissions are today numerically open to the perfect match of real-time meteorological-data, and patterns data at diverse scales for prompt/early and chronic tritium dose assessments. The trends towards integrated-numerical-platforms for environmental-dose assessments of large tritium inventory facilities under development.

  16. Assessment of Effective Dose Equivalent of Indoor 222Rn Daughters in Inchass

    International Nuclear Information System (INIS)

    Ali, E.M.; Taha, T.M.; Gomaa, M.A.; El-Hussein, A.M.; Ahmad, A.A.

    2000-01-01

    The dominant component of natural radiation dose for the general population comes from the radon gas 222 Rn and its short-lived decay products, Ra A ( 214 Po), Ra B ( 214 Pb), Ra C ( 214 Bi), Ra C( 214 Po) in the breathing air. The objective of the present work is to assess the affective dose equivalent of the inhalation exposure of indoor 222 Rn for occupational workers. Average indon concentrations (Bqm -3 ) were monitored in several departments in Nuclear Research Center by radon monitor. We have calculated the lung dose equivalent and the effective dose equivalent for the Egyptian workers due to inhalation exposure of an equilibrium equivalent concentrations of radon daughters which varies from 0.27 to 2.5 mSvy -1 and 0.016 to 0.152mSvy -1 respectively. The annual effective doses obtained are within the accepted range of ICRP recommendations

  17. Mortality from breast cancer after irradiation during fluoroscopic examinations in patients being treated for tuberculosis

    International Nuclear Information System (INIS)

    Miller, A.B.; Howe, G.R.; Sherman, G.J.; Lindsay, J.P.; Yaffe, M.J.; Dinner, P.J.; Risch, H.A.; Preston, D.L.

    1989-01-01

    The increasing use of mammography to screen asymptomatic women makes it important to know the risk of breast cancer associated with exposure to low levels of ionizing radiation. We examined the mortality from breast cancer in a cohort of 31,710 women who had been treated for tuberculosis at Canadian sanatoriums between 1930 and 1952. A substantial proportion (26.4 percent) had received radiation doses to the breast of 10 cGy or more from repeated fluoroscopic examinations during therapeutic pneumothoraxes. Women exposed to greater than or equal to 10 cGy of radiation had a relative risk of death from breast cancer of 1.36, as compared with those exposed to less than 10 cGy (95 percent confidence interval, 1.11 to 1.67; P = 0.001). The data were most consistent with a linear dose-response relation. The risk was greatest among women who had been exposed to radiation when they were between 10 and 14 years of age; they had a relative risk of 4.5 per gray, and an additive risk of 6.1 per 10(4) person-years per gray. With increasing age at first exposure, there was substantially less excess risk, and the radiation effect appeared to peak approximately 25 to 34 years after the first exposure. Our additive model for lifetime risk predicts that exposure to 1 cGy at the age of 40 increases the number of deaths from breast cancer by 42 per million women. We conclude that the risk of breast cancer associated with radiation decreases sharply with increasing age at exposure and that even a small benefit to women of screening mammography would outweigh any possible risk of radiation-induced breast cancer

  18. Rectal dose assessment in patients submitted to high-dose-rate brachytherapy for uterine cervix cancer; Avaliacao da dose no reto em pacientes submetidas a braquiterapia de alta taxa de dose para o tratamento do cancer do colo uterino

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Jetro Pereira de [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Faculdade de Medicina; Rosa, Luiz Antonio Ribeiro da [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)], e-mail: lrosa@ird.gov.br; Batista, Delano Valdivino Santos; Bardella, Lucia Helena [Instituto Nacional de Cancer (INCA), Rio de Janeiro, RJ (Brazil). Unit of Medical Physics; Carvalho, Arnaldo Rangel [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. of Thermoluminescent Dosimetry

    2009-03-15

    Objective: The present study was aimed at developing a thermoluminescent dosimetric system capable of assessing the doses delivered to the rectum of patients submitted to high-dose-rate brachytherapy for uterine cervix cancer. Materials and methods: LiF:Mg,Ti,Na powder was the thermoluminescent material utilized for evaluating the rectal dose. The powder was divided into small portions (34 mg) which were accommodated in a capillary tube. This tube was placed into a rectal probe that was introduced into the patient's rectum. Results: The doses delivered to the rectum of six patients submitted to high-dose-rate brachytherapy for uterine cervix cancer evaluated by means of thermoluminescent dosimeters presented a good agreement with the planned values based on two orthogonal (anteroposterior and lateral) radiographic images of the patients. Conclusion: The thermoluminescent dosimetric system developed in the present study is simple and easy to be utilized as compared to other rectal dosimetry methods. The system has shown to be effective in the evaluation of rectal doses in patients submitted to high-dose-rate brachytherapy for uterine cervix cancer. (author)

  19. Objective assessment of image quality and dose reduction in CT iterative reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Vaishnav, J. Y., E-mail: jay.vaishnav@fda.hhs.gov; Jung, W. C. [Diagnostic X-Ray Systems Branch, Office of In Vitro Diagnostic Devices and Radiological Health, Center for Devices and Radiological Health, United States Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, Maryland 20993 (United States); Popescu, L. M.; Zeng, R.; Myers, K. J. [Division of Imaging and Applied Mathematics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, Maryland 20993 (United States)

    2014-07-15

    Purpose: Iterative reconstruction (IR) algorithms have the potential to reduce radiation dose in CT diagnostic imaging. As these algorithms become available on the market, a standardizable method of quantifying the dose reduction that a particular IR method can achieve would be valuable. Such a method would assist manufacturers in making promotional claims about dose reduction, buyers in comparing different devices, physicists in independently validating the claims, and the United States Food and Drug Administration in regulating the labeling of CT devices. However, the nonlinear nature of commercially available IR algorithms poses challenges to objectively assessing image quality, a necessary step in establishing the amount of dose reduction that a given IR algorithm can achieve without compromising that image quality. This review paper seeks to consolidate information relevant to objectively assessing the quality of CT IR images, and thereby measuring the level of dose reduction that a given IR algorithm can achieve. Methods: The authors discuss task-based methods for assessing the quality of CT IR images and evaluating dose reduction. Results: The authors explain and review recent literature on signal detection and localization tasks in CT IR image quality assessment, the design of an appropriate phantom for these tasks, possible choices of observers (including human and model observers), and methods of evaluating observer performance. Conclusions: Standardizing the measurement of dose reduction is a problem of broad interest to the CT community and to public health. A necessary step in the process is the objective assessment of CT image quality, for which various task-based methods may be suitable. This paper attempts to consolidate recent literature that is relevant to the development and implementation of task-based methods for the assessment of CT IR image quality.

  20. Objective assessment of image quality and dose reduction in CT iterative reconstruction

    International Nuclear Information System (INIS)

    Vaishnav, J. Y.; Jung, W. C.; Popescu, L. M.; Zeng, R.; Myers, K. J.

    2014-01-01

    Purpose: Iterative reconstruction (IR) algorithms have the potential to reduce radiation dose in CT diagnostic imaging. As these algorithms become available on the market, a standardizable method of quantifying the dose reduction that a particular IR method can achieve would be valuable. Such a method would assist manufacturers in making promotional claims about dose reduction, buyers in comparing different devices, physicists in independently validating the claims, and the United States Food and Drug Administration in regulating the labeling of CT devices. However, the nonlinear nature of commercially available IR algorithms poses challenges to objectively assessing image quality, a necessary step in establishing the amount of dose reduction that a given IR algorithm can achieve without compromising that image quality. This review paper seeks to consolidate information relevant to objectively assessing the quality of CT IR images, and thereby measuring the level of dose reduction that a given IR algorithm can achieve. Methods: The authors discuss task-based methods for assessing the quality of CT IR images and evaluating dose reduction. Results: The authors explain and review recent literature on signal detection and localization tasks in CT IR image quality assessment, the design of an appropriate phantom for these tasks, possible choices of observers (including human and model observers), and methods of evaluating observer performance. Conclusions: Standardizing the measurement of dose reduction is a problem of broad interest to the CT community and to public health. A necessary step in the process is the objective assessment of CT image quality, for which various task-based methods may be suitable. This paper attempts to consolidate recent literature that is relevant to the development and implementation of task-based methods for the assessment of CT IR image quality

  1. ARN Training Course on Advance Methods for Internal Dose Assessment: Application of Ideas Guidelines

    International Nuclear Information System (INIS)

    Rojo, A.M.; Gomez Parada, I.; Puerta Yepes, N.; Gossio, S.

    2010-01-01

    Dose assessment in case of internal exposure involves the estimation of committed effective dose based on the interpretation of bioassay measurement, and the assumptions of hypotheses on the characteristics of the radioactive material and the time pattern and the pathway of intake. The IDEAS Guidelines provide a method to harmonize dose evaluations using criteria and flow chart procedures to be followed step by step. The EURADOS Working Group 7 'Internal Dosimetry', in collaboration with IAEA and Czech Technical University (CTU) in Prague, promoted the 'EURADOS/IAEA Regional Training Course on Advanced Methods for Internal Dose Assessment: Application of IDEAS Guidelines' to broaden and encourage the use of IDEAS Guidelines, which took place in Prague (Czech Republic) from 2-6 February 2009. The ARN identified the relevance of this training and asked for a place for participating on this activity. After that, the first training course in Argentina took place from 24-28 August for training local internal dosimetry experts. (authors)

  2. Summary of the dose assessment tool for diagnostic X-ray CT, WAZA-ARIv2

    International Nuclear Information System (INIS)

    Koba, Yosuke

    2016-01-01

    WAZA-ARIv2 is the web-based open system for the dose assessment for diagnostic X-ray CT. Amid growing interest about the dose assessment for medical exposure, WAZA-ARIv2 is opened to the public from January 2015 and attracts rising attention. Using WAZA-ARIv2 system, users can calculate exposure dose to consider patient's age and body shape, and can register the calculation results on WAZA-ARIv2 server for checking as histogram statistics. This paper reviews the background of development of WAZA-ARI system, the comparison of characteristics between WAZA-ARIv2 and other tools, and the calculation method of organ dose in WAZA-ARIv2. (author)

  3. Uncertainty of fast biological radiation dose assessment for emergency response scenarios.

    Science.gov (United States)

    Ainsbury, Elizabeth A; Higueras, Manuel; Puig, Pedro; Einbeck, Jochen; Samaga, Daniel; Barquinero, Joan Francesc; Barrios, Lleonard; Brzozowska, Beata; Fattibene, Paola; Gregoire, Eric; Jaworska, Alicja; Lloyd, David; Oestreicher, Ursula; Romm, Horst; Rothkamm, Kai; Roy, Laurence; Sommer, Sylwester; Terzoudi, Georgia; Thierens, Hubert; Trompier, Francois; Vral, Anne; Woda, Clemens

    2017-01-01

    Reliable dose estimation is an important factor in appropriate dosimetric triage categorization of exposed individuals to support radiation emergency response. Following work done under the EU FP7 MULTIBIODOSE and RENEB projects, formal methods for defining uncertainties on biological dose estimates are compared using simulated and real data from recent exercises. The results demonstrate that a Bayesian method of uncertainty assessment is the most appropriate, even in the absence of detailed prior information. The relative accuracy and relevance of techniques for calculating uncertainty and combining assay results to produce single dose and uncertainty estimates is further discussed. Finally, it is demonstrated that whatever uncertainty estimation method is employed, ignoring the uncertainty on fast dose assessments can have an important impact on rapid biodosimetric categorization.

  4. Realistic retrospective dose assessments to members of the public around Spanish nuclear facilities

    International Nuclear Information System (INIS)

    Jimenez, M.A.; Martin-Valdepenas, J.M.; Garcia-Talavera, M.; Martin-Matarranz, J.L.; Salas, M.R.; Serrano, J.I.; Ramos, L.M.

    2011-01-01

    In the frame of an epidemiological study carried out in the influence areas around the Spanish nuclear facilities (ISCIII-CSN, 2009. Epidemiological Study of The Possible Effect of Ionizing Radiations Deriving from The Operation of Spanish Nuclear Fuel Cycle Facilities on The Health of The Population Living in Their Vicinity. Final report December 2009. Ministerio de Ciencia e Innovacion, Instituto de Salud Carlos III, Consejo de Seguridad Nuclear. Madrid. Available from: (http://www.csn.es/images/stories/actualidad_datos/especiales/epidemiologico/epidemiological_study.pdf)), annual effective doses to public have been assessed by the Spanish Nuclear Safety Council (CSN) for over 45 years using a retrospective realistic-dose methodology. These values are compared with data from natural radiation exposure. For the affected population, natural radiation effective doses are in average 2300 times higher than effective doses due to the operation of nuclear installations (nuclear power stations and fuel cycle facilities). When considering the impact on the whole Spanish population, effective doses attributable to nuclear facilities represent in average 3.5 x 10 -5 mSv/y, in contrast to 1.6 mSv/y from natural radiation or 1.3 mSv/y from medical exposures. - Highlights: → Most comprehensive dose assessment to public by nuclear facilities ever done in Spain. → Dose to public is dominated by liquid effluent pathways for the power stations. → Dose to public is dominated by Rn inhalation for milling and mining facilities. → Average annual doses to public in influence areas are negligible (10 μSv/y or less). → Doses from facilities average 3.5 x 10 -2 μSv/y per person onto whole Spanish population.

  5. Realistic retrospective dose assessments to members of the public around Spanish nuclear facilities

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, M.A., E-mail: majg@csn.es [Consejo de Seguridad Nuclear (CSN), Pedro Justo Dorado Dellmans 11, E-28040 Madrid (Spain); Martin-Valdepenas, J.M.; Garcia-Talavera, M.; Martin-Matarranz, J.L.; Salas, M.R.; Serrano, J.I.; Ramos, L.M. [Consejo de Seguridad Nuclear (CSN), Pedro Justo Dorado Dellmans 11, E-28040 Madrid (Spain)

    2011-11-15

    In the frame of an epidemiological study carried out in the influence areas around the Spanish nuclear facilities (ISCIII-CSN, 2009. Epidemiological Study of The Possible Effect of Ionizing Radiations Deriving from The Operation of Spanish Nuclear Fuel Cycle Facilities on The Health of The Population Living in Their Vicinity. Final report December 2009. Ministerio de Ciencia e Innovacion, Instituto de Salud Carlos III, Consejo de Seguridad Nuclear. Madrid. Available from: (http://www.csn.es/images/stories/actualidad{sub d}atos/especiales/epidemiologico/epidemiological{sub s}tudy.pdf)), annual effective doses to public have been assessed by the Spanish Nuclear Safety Council (CSN) for over 45 years using a retrospective realistic-dose methodology. These values are compared with data from natural radiation exposure. For the affected population, natural radiation effective doses are in average 2300 times higher than effective doses due to the operation of nuclear installations (nuclear power stations and fuel cycle facilities). When considering the impact on the whole Spanish population, effective doses attributable to nuclear facilities represent in average 3.5 x 10{sup -5} mSv/y, in contrast to 1.6 mSv/y from natural radiation or 1.3 mSv/y from medical exposures. - Highlights: > Most comprehensive dose assessment to public by nuclear facilities ever done in Spain. > Dose to public is dominated by liquid effluent pathways for the power stations. > Dose to public is dominated by Rn inhalation for milling and mining facilities. > Average annual doses to public in influence areas are negligible (10 {mu}Sv/y or less). > Doses from facilities average 3.5 x 10{sup -2} {mu}Sv/y per person onto whole Spanish population.

  6. Radiological dose assessment related to management of naturally occurring radioactive materials generated by the petroleum industry

    International Nuclear Information System (INIS)

    Smith, K.P.; Blunt, D.L.; Williams, G.P.

    1996-09-01

    A preliminary radiological dose assessment of equipment decontamination, subsurface disposal, landspreading, equipment smelting, and equipment burial was conducted to address concerns regarding the presence of naturally occurring radioactive materials (NORM) in production waste streams. The assessment estimated maximum individual dose equivalents for workers and the general public. Sensitivity analyses of certain input parameters also were conducted. On the basis of this assessment, it is concluded that (1) regulations requiring workers to wear respiratory protection during equipment cleaning operations are likely to result in lower worker doses, (2) underground injection and downhole encapsulation of NORM wastes present a negligible risk to the general public, and (3) potential doses to workers and the general public related to smelting NORM-contaminated equipment can be controlled by limiting the contamination level of the initial feed. It is recommended that (1) NORM wastes be further characterized to improve studies of potential radiological doses; (2) states be encouraged to permit subsurface disposal of NORM more readily, provided further assessments support this study; results; (3) further assessment of landspreading NORM wastes be conducted; and (4) the political, economic, sociological, and nonradiological issues related to smelting NORM-contaminated equipment be studied to fully examine the feasibility of this disposal option

  7. REIDAC. A software package for retrospective dose assessment in internal contamination with radionuclides

    International Nuclear Information System (INIS)

    Kurihara, Osamu; Kanai, Katsuta; Takada, Chie; Takasaki, Koji; Ito, Kimio; Momose, Takumaro; Hato, Shinji; Ikeda, Hiroshi; Oeda, Mikihiro; Kurosawa, Naohiro; Fukutsu, Kumiko; Yamada, Yuji; Akashi, Makoto

    2007-01-01

    For cases of internal contamination with radionuclides, it is necessary to perform an internal dose assessment to facilitate radiation protection. For this purpose, the ICRP has supplied the dose coefficients and the retention and excretion rates for various radionuclides. However, these dosimetric quantities are calculated under typical conditions and are not necessarily detailed enough for dose assessment situations in which specific information on the incident or/and individual biokinetic characteristics could or should be taken into account retrospectively. This paper describes a newly developed PC-based software package called Retrospective Internal Dose Assessment Code (REIDAC) that meets the needs of retrospective dose assessment. REIDAC is made up of a series of calculation programs and a package of software. The former calculates the dosimetric quantities for any radionuclide being assessed and the latter provides a user with the graphical user interface (GUI) for executing the programs, editing parameter values and displaying results. The accuracy of REIDAC was verified by comparisons with dosimetric quantities given in the ICRP publications. This paper presents the basic structure of REIDAC and its calculation methods. Sensitivity analysis of the aerosol size for 239 Pu compounds and provisional calculations for wound contamination with 241 Am were performed as examples of the practical application of REIDAC. (author)

  8. A Unified Probabilistic Framework for Dose-Response Assessment of Human Health Effects.

    Science.gov (United States)

    Chiu, Weihsueh A; Slob, Wout

    2015-12-01

    When chemical health hazards have been identified, probabilistic dose-response assessment ("hazard characterization") quantifies uncertainty and/or variability in toxicity as a function of human exposure. Existing probabilistic approaches differ for different types of endpoints or modes-of-action, lacking a unifying framework. We developed a unified framework for probabilistic dose-response assessment. We established a framework based on four principles: a) individual and population dose responses are distinct; b) dose-response relationships for all (including quantal) endpoints can be recast as relating to an underlying continuous measure of response at the individual level; c) for effects relevant to humans, "effect metrics" can be specified to define "toxicologically equivalent" sizes for this underlying individual response; and d) dose-response assessment requires making adjustments and accounting for uncertainty and variability. We then derived a step-by-step probabilistic approach for dose-response assessment of animal toxicology data similar to how nonprobabilistic reference doses are derived, illustrating the approach with example non-cancer and cancer datasets. Probabilistically derived exposure limits are based on estimating a "target human dose" (HDMI), which requires risk management-informed choices for the magnitude (M) of individual effect being protected against, the remaining incidence (I) of individuals with effects ≥ M in the population, and the percent confidence. In the example datasets, probabilistically derived 90% confidence intervals for HDMI values span a 40- to 60-fold range, where I = 1% of the population experiences ≥ M = 1%-10% effect sizes. Although some implementation challenges remain, this unified probabilistic framework can provide substantially more complete and transparent characterization of chemical hazards and support better-informed risk management decisions.

  9. Development of dose assessment code for release of tritium during normal operation of nuclear power plants

    International Nuclear Information System (INIS)

    Duran, J.; Malatova, I.

    2009-01-01

    A computer code PTM H TO has been developed to assess tritium doses to the general public. The code enables to simulate the behavior of tritium in the environment released into the atmosphere under normal operation of nuclear power plants. Code can calculate the doses for the three chemical and physical forms: tritium gas (HT), tritiated water vapor and water drops (HTO). The models in this code consist of the tritium transfer model including oxidation of HT to HTO and reemission of HTO from soil to the atmosphere, and the dose calculation model

  10. Review of calculational models and computer codes for environmental dose assessment of radioactive releases

    International Nuclear Information System (INIS)

    Strenge, D.L.; Watson, E.C.; Droppo, J.G.

    1976-06-01

    The development of technological bases for siting nuclear fuel cycle facilities requires calculational models and computer codes for the evaluation of risks and the assessment of environmental impact of radioactive effluents. A literature search and review of available computer programs revealed that no one program was capable of performing all of the great variety of calculations (i.e., external dose, internal dose, population dose, chronic release, accidental release, etc.). Available literature on existing computer programs has been reviewed and a description of each program reviewed is given

  11. Review of calculational models and computer codes for environmental dose assessment of radioactive releases

    Energy Technology Data Exchange (ETDEWEB)

    Strenge, D.L.; Watson, E.C.; Droppo, J.G.

    1976-06-01

    The development of technological bases for siting nuclear fuel cycle facilities requires calculational models and computer codes for the evaluation of risks and the assessment of environmental impact of radioactive effluents. A literature search and review of available computer programs revealed that no one program was capable of performing all of the great variety of calculations (i.e., external dose, internal dose, population dose, chronic release, accidental release, etc.). Available literature on existing computer programs has been reviewed and a description of each program reviewed is given.

  12. Characteristics of the graded wildlife dose assessment code K-BIOTA and its application

    International Nuclear Information System (INIS)

    Keum, Dong Kwon; Jun, In; Lim, Kwang Muk; Kim, Byeong Ho; Choi, Yong Ho

    2015-01-01

    This paper describes the technical background for the Korean wildlife radiation dose assessment code, K-BIOTA, and the summary of its application. The K-BIOTA applies the graded approaches of 3 levels including the screening assessment (Level 1 and 2), and the detailed assessment based on the site specific data (Level 3). The screening level assessment is a preliminary step to determine whether the detailed assessment is needed, and calculates the dose rate for the grouped organisms, rather than an individual biota. In the Level 1 assessment, the risk quotient (RQ) is calculated by comparing the actual media concentration with the environmental media concentration limit (EMCL) derived from a bench-mark screening reference dose rate. If RQ for the Level 1 assessment is less than 1, it can be determined that the ecosystem would maintain its integrity, and the assessment is terminated. If the RQ is greater than 1, the Level 2 assessment, which calculates RQ using the average value of the concentration ratio (CR) and equilibrium distribution coefficient (Kd) for the grouped organisms, is carried out for the more realistic assessment. Thus, the Level 2 assessment is less conservative than the Level 1 assessment. If RQ for the Level 2 assessment is less than 1, it can be determined that the ecosystem would maintain its integrity, and the assessment is terminated. If the RQ is greater than 1, the Level 3 assessment is performed for the detailed assessment. In the Level 3 assessment, the radiation dose for the representative organism of a site is calculated by using the site specific data of occupancy factor, CR and Kd. In addition, the K-BIOTA allows the uncertainty analysis of the dose rate on CR, Kd and environmental medium concentration among input parameters optionally in the Level 3 assessment. The four probability density functions of normal, lognormal, uniform and exponential distribution can be applied. The applicability of the code was tested through the

  13. Characteristics of the graded wildlife dose assessment code K-BIOTA and its application

    Energy Technology Data Exchange (ETDEWEB)

    Keum, Dong Kwon; Jun, In; Lim, Kwang Muk; Kim, Byeong Ho; Choi, Yong Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-12-15

    This paper describes the technical background for the Korean wildlife radiation dose assessment code, K-BIOTA, and the summary of its application. The K-BIOTA applies the graded approaches of 3 levels including the screening assessment (Level 1 and 2), and the detailed assessment based on the site specific data (Level 3). The screening level assessment is a preliminary step to determine whether the detailed assessment is needed, and calculates the dose rate for the grouped organisms, rather than an individual biota. In the Level 1 assessment, the risk quotient (RQ) is calculated by comparing the actual media concentration with the environmental media concentration limit (EMCL) derived from a bench-mark screening reference dose rate. If RQ for the Level 1 assessment is less than 1, it can be determined that the ecosystem would maintain its integrity, and the assessment is terminated. If the RQ is greater than 1, the Level 2 assessment, which calculates RQ using the average value of the concentration ratio (CR) and equilibrium distribution coefficient (Kd) for the grouped organisms, is carried out for the more realistic assessment. Thus, the Level 2 assessment is less conservative than the Level 1 assessment. If RQ for the Level 2 assessment is less than 1, it can be determined that the ecosystem would maintain its integrity, and the assessment is terminated. If the RQ is greater than 1, the Level 3 assessment is performed for the detailed assessment. In the Level 3 assessment, the radiation dose for the representative organism of a site is calculated by using the site specific data of occupancy factor, CR and Kd. In addition, the K-BIOTA allows the uncertainty analysis of the dose rate on CR, Kd and environmental medium concentration among input parameters optionally in the Level 3 assessment. The four probability density functions of normal, lognormal, uniform and exponential distribution can be applied. The applicability of the code was tested through the

  14. A review of the uncertainties in internal radiation dose assessment for inhaled thorium

    International Nuclear Information System (INIS)

    Hewson, G.S.

    1989-01-01

    Present assessments of internal radiation dose to designated radiation workers in the mineral sands industry, calculated using ICRP 26/30 methodology and data, indicate that some workers approach and exceed statutory radiation dose limits. Such exposures are indicative of the need for a critical assessment of work and operational procedures and also of metabolic and dosimetric models used to estimate internal dose. This paper reviews past occupational exposure experience with inhaled thorium compounds, examines uncertainties in the underlying radiation protection models, and indicates the effect of alternative assumptions on the calculation of committed effective dose equivalent. The extremely low recommended inhalation limits for thorium in air do not appear to be well supported by studies on the health status of former thorium refinery workers who were exposed to thorium well in excess of presently accepted limits. The effect of cautious model assumptions is shown to result in internal dose assessments that could be up to an order of magnitude too high. It is concluded that the effect of such uncertainty constrains the usefulness of internal dose estimates as a reliable indicator of actual health risk. 26 refs., 5 figs., 3 tabs

  15. How accurately can the peak skin dose in fluoroscopy be determined using indirect dose metrics?

    International Nuclear Information System (INIS)

    Jones, A. Kyle; Ensor, Joe E.; Pasciak, Alexander S.

    2014-01-01

    Purpose: Skin dosimetry is important for fluoroscopically-guided interventions, as peak skin doses (PSD) that result in skin reactions can be reached during these procedures. There is no consensus as to whether or not indirect skin dosimetry is sufficiently accurate for fluoroscopically-guided interventions. However, measuring PSD with film is difficult and the decision to do so must be madea priori. The purpose of this study was to assess the accuracy of different types of indirect dose estimates and to determine if PSD can be calculated within ±50% using indirect dose metrics for embolization procedures. Methods: PSD were measured directly using radiochromic film for 41 consecutive embolization procedures at two sites. Indirect dose metrics from the procedures were collected, including reference air kerma. Four different estimates of PSD were calculated from the indirect dose metrics and compared along with reference air kerma to the measured PSD for each case. The four indirect estimates included a standard calculation method, the use of detailed information from the radiation dose structured report, and two simplified calculation methods based on the standard method. Indirect dosimetry results were compared with direct measurements, including an analysis of uncertainty associated with film dosimetry. Factors affecting the accuracy of the different indirect estimates were examined. Results: When using the standard calculation method, calculated PSD were within ±35% for all 41 procedures studied. Calculated PSD were within ±50% for a simplified method using a single source-to-patient distance for all calculations. Reference air kerma was within ±50% for all but one procedure. Cases for which reference air kerma or calculated PSD exhibited large (±35%) differences from the measured PSD were analyzed, and two main causative factors were identified: unusually small or large source-to-patient distances and large contributions to reference air kerma from cone

  16. Development of internal dose assessment procedure for workers in industries using raw materials containing naturally occurring radioactive materials

    International Nuclear Information System (INIS)

    Choi, Cheol Kyu; KIm, Yong Geon; Ji, Seung Woo; Kim, Kwang Pyo; Koo, Bon Cheol; Chang, Byung Uck

    2016-01-01

    It is necessary to assess radiation dose to workers due to inhalation of airborne particulates containing naturally occurring radioactive materials (NORM) to ensure radiological safety required by the Natural Radiation Safety Management Act. The objective of this study is to develop an internal dose assessment procedure for workers at industries using raw materials containing natural radionuclides. The dose assessment procedure was developed based on harmonization, accuracy, and proportionality. The procedure includes determination of dose assessment necessity, preliminary dose estimation, airborne particulate sampling and characterization, and detailed assessment of radiation dose. The developed dose assessment procedure is as follows. Radioactivity concentration criteria to determine dose assessment necessity are 10 Bq·g-1 for 40K and 1 Bq·g-1 for the other natural radionuclides. The preliminary dose estimation is performed using annual limit on intake (ALI). The estimated doses are classified into 3 groups (<0.1 mSv, 0.1-0.3 mSv, and >0.3 mSv). Air sampling methods are determined based on the dose estimates. Detailed dose assessment is performed using air sampling and particulate characterization. The final dose results are classified into 4 different levels (<0.1 mSv, 0.1-0.3 mSv, 0.3-1 mSv, and >1 mSv). Proper radiation protection measures are suggested according to the dose level. The developed dose assessment procedure was applied for NORM industries in Korea, including coal combustion, phosphate processing, and monazite handing facilities. The developed procedure provides consistent dose assessment results and contributes to the establishment of optimization of radiological protection in NORM industries

  17. Development of internal dose assessment procedure for workers in industries using raw materials containing naturally occurring radioactive materials

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Cheol Kyu; KIm, Yong Geon; Ji, Seung Woo; Kim, Kwang Pyo [College of Engineering, Kyung Hee University, Yongin (Korea, Republic of); Koo, Bon Cheol; Chang, Byung Uck [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2016-09-15

    It is necessary to assess radiation dose to workers due to inhalation of airborne particulates containing naturally occurring radioactive materials (NORM) to ensure radiological safety required by the Natural Radiation Safety Management Act. The objective of this study is to develop an internal dose assessment procedure for workers at industries using raw materials containing natural radionuclides. The dose assessment procedure was developed based on harmonization, accuracy, and proportionality. The procedure includes determination of dose assessment necessity, preliminary dose estimation, airborne particulate sampling and characterization, and detailed assessment of radiation dose. The developed dose assessment procedure is as follows. Radioactivity concentration criteria to determine dose assessment necessity are 10 Bq·g-1 for 40K and 1 Bq·g-1 for the other natural radionuclides. The preliminary dose estimation is performed using annual limit on intake (ALI). The estimated doses are classified into 3 groups (<0.1 mSv, 0.1-0.3 mSv, and >0.3 mSv). Air sampling methods are determined based on the dose estimates. Detailed dose assessment is performed using air sampling and particulate characterization. The final dose results are classified into 4 different levels (<0.1 mSv, 0.1-0.3 mSv, 0.3-1 mSv, and >1 mSv). Proper radiation protection measures are suggested according to the dose level. The developed dose assessment procedure was applied for NORM industries in Korea, including coal combustion, phosphate processing, and monazite handing facilities. The developed procedure provides consistent dose assessment results and contributes to the establishment of optimization of radiological protection in NORM industries.

  18. Study on dose assessment in surrounding environment of the Tono Mine associated with closure activity

    International Nuclear Information System (INIS)

    Sasao, Eiji

    2012-07-01

    Dose assessment associated with closure activity of the Tono Mine has been performed. In this assessment, exposure dose has been calculated on groundwater and surface water migration of radionuclide from 1) waste rock in the waste rock dump facility, 2) mining waste in the mining waste facility, and 3) uranium ore and waste rock backfilled in the shafts and galleries. Direct and skyshine gamma rays and exposure of exhalated radon from the waste rock dump has also been evaluated. An evaluation tool developed for safety assessment for sub-surface disposal of radioactive waste is utilized for this assessment. Localities for dose evaluation are selected at the Higashihoragawa and Hiyoshigawa based on the topography around the Tono Mine and groundwater flow simulation. Evaluation scenarios are classified into 'Scenario for intake of agricultural product' as the base scenario, and 'Scenario for intake of groundwater' as the alternative scenario. Parameters for dose assessment are set-up based on the existing data. But the range and uncertainty of parameters are taken into account in the 'alternative cases'. As the result of dose assessment, maximum exposure dose of the base scenario is 0.08mSv/year, and 0.09mSv/year including direct and skyshine gamma rays and exposure of exhalatedradon at the Higashihoragawa. Maximum exposure dose of the alternative scenario is 0.08mSv/year (0.09mSv/year including direct and skyshine gamma rays and exposure of exhalated radon). On the alternative cases, exposure doses are calculated as 0.05-0.14mSv/year in both of the base and alternative scenarios. At the Hiyoshigawa, maximum exposure dose is less than 0.001mSv/year (1x10 -6 mSv/year) for the base scenario, and 0.001mSv/year for the alternative scenario. On the alternative cases, maximum exposure doses are less than 0.001mSv/year for all cases of the base scenario and 0.0006-0.002mSv/year for the alternative scenario. (author)

  19. Updated radiological dose assessment of Bikini and Eneu Islands at Bikini Atoll

    International Nuclear Information System (INIS)

    Robison, W.L.; Mount, M.E.; Phillips, W.A.; Stuart, M.L.; Thompson, S.E.; Conrado, C.L.; Stoker, A.C.

    1982-01-01

    This report is part of a continuing effort to refine dose assessments for resettlement options at Bikini Atoll. Radionuclide concentration data developed at Bikini Atoll since 1977 have been used in conjunction with recent dietary information and current dose models to develop the annual dose rate and 30- and 50-y integral doses presented here for Bikini and Eneu Island living patterns. The terrestrial food chain is the most significant exposure pathway--it contributes more than 50% of the total dose--and external gamma exposure is the second most significant pathway. Other pathways evaluated are the marine food chain, drinking water, and inhalation. Cesium-137 produces more than 85% of the predicted dose; 90 Sr is the second most significant radionuclide; 60 Co contributes to the external gamma exposure in varying degrees, but is a small part of the total predicted dose; the transuranic radionuclides contribute a small portion of the total predicted lung and bone doses but do present a long-term source of exposure. Maximum annual dose rates for Bikini Island are about 1 rem/y for the whole body and bone marrow when imported foods are available and about 1.9 rem/y when imports are unavailable. Maximum annual dose rates for Eneu Island when imports are available are 130 mrem/y for the whole body and 136 mrem/y for bone marrow. Similar doses when imported foods are unavailable are 245 and 263 mrem/y, respectively. The 30-y integral doses for Bikini Island are about 23 rem for whole body and bone marrow when imported foods are available and more than 40 rem when imports are unavailable. The Eneu Island 30-y integral doses for whole body and bone marrow are about 3 rem when imports are available and 5.5 and 6.1 rem, respectively, when imports are unavailable. Doses from living patterns involving some combination of Bikini and Eneu Islands fall between the doses listed above for each island separately

  20. Lower radiation burden in state of the art fluoroscopic cystography compared to direct isotope cystography in children.

    Science.gov (United States)

    Haid, Bernhard; Becker, Tanja; Koen, Mark; Berger, Christoph; Langsteger, Werner; Gruy, Bernhard; Putz, Ernst; Haid, Stephanie; Oswald, Josef

    2015-02-01

    Both, fluoroscopic voiding cystourethrography (fVCUG) and direct isotope cystography (DIC) are diagnostic tools commonly used in pediatric urology. Both methods can detect vesicoureteral reflux (VUR) with a high sensitivity. Whilst the possibility to depict anatomical details and important structures as for instance the urethra in boys or the detailed calyceal anatomy are advantages of fVCUG, a lower radiation burden is thought to be the main advantage of DIC. In the last decade, however, a rapid technical evolution has occurred in fluoroscopy by implementing digital grid-controlled, variable rate, pulsed acquisition technique. As documented in literature this led to a substantial decrease in radiation burden conferred during fVCUGs. To question the common belief that direct isotope cystography confers less radiation burden compared to state of the art fluoroscopic voiding cystography. Radiation burden of direct isotope cystography in 92 children and in additional 7 children after an adaption of protocol was compared to radiation burden of fluoroscopic voiding cystourethrography in 51. The examinations were performed according to institutional protocols. For calculation of mean effective radiation dose [mSv] for either method published physical models correcting for age and sex were used. For DIC the model published by Stabin et al., 1998 was applied, for fVCUG two different physical models were used (Schultz et al., 1999, Lee et al., 2009). The radiation burden conferred by direct isotope cystography was significantly higher as for fluoroscopic voiding cystourethrography. The mean effective radiation dose for direct isotope cystography accounted to 0.23 mSv (± 0.34 m, median 0.085 mSv) compared to 0.015 mSv (± 0.013, median 0.008 mSv, model by Schultz et al.) - 0.024 mSv (± 0.018, median 0.018 mSv, model by Lee et al.) for fluoroscopic voiding cystourethrography. After a protocol adaption to correct for a longer examination time in DIC that was caused by

  1. Radiological assessment of worker doses during sludge mobilization and removal at the Melton Valley storage tanks

    International Nuclear Information System (INIS)

    Kerr, G.D.; Coleman, R.L.; Kocher, D.C.; Wynn, C.C.

    1996-01-01

    This report presents an assessment of potential radiation doses to workers during mobilization and removal of contaminated sludges from the Melton Valley Storage Tanks at Oak Ridge National Laboratory. The assessment is based on (1) measurements of radionuclide concentrations in sludge and supernatant liquid samples from the waste storage tanks, (2) measurements of gamma radiation levels in various areas that will be accessed by workers during normal activities, (3) calculations of gamma radiation levels for particular exposure situations, especially when the available measurements are not applicable, and (4) assumed scenarios for worker activities in radiation areas. Only doses from external exposure are estimated in this assessment. Doses from internal exposure are assumed to be controlled by containment of radioactive materials or respiratory protection of workers and are not estimated

  2. An updated dose assessment for a U.S. Nuclear Test Site - Bikini Atoll

    International Nuclear Information System (INIS)

    Robison, W.L.; Bogen, K.T.; Conrado, C.L.

    1995-10-01

    On March 1, 1954, a nuclear weapon test, code-named BRAVO, conducted at Bikini Atoll in the northern Marshall Islands contaminated the major residence island. There has been a continuing effort since 1977 to refine dose assessments for resettlement options at Bikini Atoll. Here we provide a radiological dose assessment for the main residence island, Bikini, using extensive radionuclide concentration data derived from analysis of food crops, ground water, cistern water, fish and other marine species, animals, air, and soil collected at Bikini Island as part of our continuing research and monitoring program that began in 1975. The unique composition of coral soil greatly alters the relative contribution of cesium-137 ( 137 Cs) and strontium-90 ( 90 Sr) to the total estimated dose relative to expectations based on North American and European soils. Without counter measures, cesium-137 produces 96% of the estimated dose for returning residents, mostly through uptake from the soil to terrestrial food crops but also from external gamma exposure. The doses are calculated assuming a resettlement date of 1999. The estimated maximum annual effective dose for current island conditions is 4.0 mSv when imported foods, which are now an established part of the diet, are available. The corresponding 30-, 50-, and 70-y integral effective doses are 9.1 cSv, 13 cSv, and 15 cSv, respectively. A corresponding uncertainty analysis showed that after about 5 y of residence, the 95% confidence limits on population-average dose would be ±35% of its expected value. We have evaluated various countermeasures to reduce 137 Cs in food crops. Treatment with potassium reduces the uptake of 137 Cs into food crops, and therefore the ingestion dose, to about 5% of pretreatment levels and has essentially no negative environmental consequences

  3. Environmental dose rate assessment of ITER using the Monte Carlo method

    Directory of Open Access Journals (Sweden)

    Karimian Alireza

    2014-01-01

    Full Text Available Exposure to radiation is one of the main sources of risk to staff employed in reactor facilities. The staff of a tokamak is exposed to a wide range of neutrons and photons around the tokamak hall. The International Thermonuclear Experimental Reactor (ITER is a nuclear fusion engineering project and the most advanced experimental tokamak in the world. From the radiobiological point of view, ITER dose rates assessment is particularly important. The aim of this study is the assessment of the amount of radiation in ITER during its normal operation in a radial direction from the plasma chamber to the tokamak hall. To achieve this goal, the ITER system and its components were simulated by the Monte Carlo method using the MCNPX 2.6.0 code. Furthermore, the equivalent dose rates of some radiosensitive organs of the human body were calculated by using the medical internal radiation dose phantom. Our study is based on the deuterium-tritium plasma burning by 14.1 MeV neutron production and also photon radiation due to neutron activation. As our results show, the total equivalent dose rate on the outside of the bioshield wall of the tokamak hall is about 1 mSv per year, which is less than the annual occupational dose rate limit during the normal operation of ITER. Also, equivalent dose rates of radiosensitive organs have shown that the maximum dose rate belongs to the kidney. The data may help calculate how long the staff can stay in such an environment, before the equivalent dose rates reach the whole-body dose limits.

  4. Negotiating NORM cleanup and land use limits: Practical use of dose assessment and cost benefit analysis

    International Nuclear Information System (INIS)

    Blanchard, A.D.H.

    1997-01-01

    Oil companies are presently faced with complex and costly environmental decisions, especially concerning NORM cleanup and disposal. Strict cleanup limits and disposal restrictions are established, in theory, to protect public health and environment. While public health is directly measured in terms of dose (mrem/yr), most NORM regulations adopt soil concentration limits to ensure future public health is maintained. These derived soil limits create the potential for unnecessary burden to operators without additional health benefit to society. Operators may use a dose assessment to show direct compliance with dose limits, negotiating less restrictive cleanup levels and land use limits. This paper discusses why a dose assessment is useful to Oilfield operators, NORM exposure scenarios and pathways, assessment advantages, variables and recommendations and one recent dose assessment application. Finally, a cost benefit analysis tool for regulatory negotiations will be presented allowing comparison of Oilfield NORM health benefit costs to that of other industries. One use for this tool--resulting in the savings of approximately $100,000--will be discussed

  5. The role of uncertainty analysis in dose reconstruction and risk assessment

    International Nuclear Information System (INIS)

    Hoffman, F.O.; Simon, S.L.; Thiessen. K.M.

    1996-01-01

    Dose reconstruction and risk assessment rely heavily on the use of mathematical models to extrapolate information beyond the realm of direct observation. Because models are merely approximations of real systems, their predictions are inherently uncertain. As a result, full disclosure of uncertainty in dose and risk estimates is essential to achieve scientific credibility and to build public trust. The need for formal analysis of uncertainty in model predictions was presented during the nineteenth annual meeting of the NCRP. At that time, quantitative uncertainty analysis was considered a relatively new and difficult subject practiced by only a few investigators. Today, uncertainty analysis has become synonymous with the assessment process itself. When an uncertainty analysis is used iteratively within the assessment process, it can guide experimental research to refine dose and risk estimates, deferring potentially high cost or high consequence decisions until uncertainty is either acceptable or irreducible. Uncertainty analysis is now mandated for all ongoing dose reconstruction projects within the United States, a fact that distinguishes dose reconstruction from other types of exposure and risk assessments. 64 refs., 6 figs., 1 tab

  6. Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico

    Directory of Open Access Journals (Sweden)

    Sergio Luevano-Gurrola

    2015-09-01

    Full Text Available Determining ionizing radiation in a geographic area serves to assess its effects on a population’s health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h−1. At the same sites, 48 soil samples were taken to obtain the activity concentrations of 226Ra, 232Th and 40K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h−1. Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg−1, for 226Ra, 232Th and 40K, respectively. From the analysis, the spatial distribution of 232Th, 226Ra and 40K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize.

  7. Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico.

    Science.gov (United States)

    Luevano-Gurrola, Sergio; Perez-Tapia, Angelica; Pinedo-Alvarez, Carmelo; Carrillo-Flores, Jorge; Montero-Cabrera, Maria Elena; Renteria-Villalobos, Marusia

    2015-09-30

    Determining ionizing radiation in a geographic area serves to assess its effects on a population's health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h(-1). At the same sites, 48 soil samples were taken to obtain the activity concentrations of (226)Ra, (232)Th and (40)K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h(-1). Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg(-1), for (226)Ra, (232)Th and (40)K, respectively. From the analysis, the spatial distribution of (232)Th, (226)Ra and (40)K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize.

  8. Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico

    Science.gov (United States)

    Luevano-Gurrola, Sergio; Perez-Tapia, Angelica; Pinedo-Alvarez, Carmelo; Carrillo-Flores, Jorge; Montero-Cabrera, Maria Elena; Renteria-Villalobos, Marusia

    2015-01-01

    Determining ionizing radiation in a geographic area serves to assess its effects on a population’s health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h−1. At the same sites, 48 soil samples were taken to obtain the activity concentrations of 226Ra, 232Th and 40K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h−1. Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg−1, for 226Ra, 232Th and 40K, respectively. From the analysis, the spatial distribution of 232Th, 226Ra and 40K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize. PMID:26437425

  9. RADIATION HYGIENIC MONITORING AND ASSESSMENT OF POPULATION DOSES IN RADIOACTIVELY CONTAMINATED AREAS OF TULA REGION

    Directory of Open Access Journals (Sweden)

    T. M. Chichura

    2016-01-01

    Full Text Available The goal. The analyses of radiation hygienic monitoring conducted in Tula region territories affected by the Chernobyl NPP accident regarding cesium-137 and strontium- 90 in the local foodstuffs and the analyses of populational annual effective dose. The materials and methods. The survey was conducted in Tula Region since 1997 to 2015. Over that period, more than fifty thousand samples of the main foodstuffs from the post-Chernobyl contaminated area were analyzed. Simultaneously with that, the external gamma - radiation dose rate was measured in the fixed control points. The dynamics of cesium -137 and strontium-90 content in foodstuffs were assessed along with the maximum values of the mean annual effective doses to the population and the contribution of the collective dose from medical exposures into the structure of the annual effective collective dose to the population. The results. The amount of cesium-137 and strontium -90 in the local foodstuffs was identified. The external gamma- radiation dose rate values were found to be stable and not exceeding the natural fluctuations range typical for the middle latitudes of Russia’s European territory. The maximum mean annual effective dose to the population reflects the stable radiation situation and does not exceed the permissible value of 1 mSv. The contribution of the collective dose from medical exposures of the population has been continuously reducing as well as the average individual dose to the population per one medical treatment under the annual increase of the medical treatments quantities. The conclusion. There is no exceedance of the admissible levels of cesium-137 and strontium- 90 content in the local foodstuffs. The mean annual effective dose to the population has decreased which makes it possible to transfer the settlements affected by the Chernobyl NPP accident to normal life style. This is covered by the draft concept of the settlements’ transfer to normal life style.

  10. Animal data on GI-tract uptake of plutonium - implications for environmental dose assessments

    International Nuclear Information System (INIS)

    Kocher, D.C.; Ryan, M.T.

    1983-01-01

    A selection of published data on GI-tract uptake of ingested plutonium in animals is reviewed for the purpose of estimating an uptake fraction which would be appropriate for environmental dose assessments in adult humans. Recent data in the adult rat and guinea pig suggest that a GI-tract uptake fraction of 10 -3 would be a reasonable and prudent choice for ingestion of environmental plutonium by adults. This value is a factor of ten larger than the value currently recommended by the International Commission on Radiological Protection for assessing doses from occupational exposures. (author)

  11. Fluoroscopically-Guided Posterior Approach for Shoulder Magnetic Resonance Arthrography: Comparison with Conventional Anterior Approach

    International Nuclear Information System (INIS)

    Yoo, Koun J.; Ha, Doo Hoe; Lee, Sang Min

    2011-01-01

    To prospectively evaluate the usefulness of the fluoroscopically-guided posterior approach compared with the anterior approach for shoulder magnetic resonance(MR) arthrography. Institutional review board approval and informed consent were obtained. Among 60 shoulder MR arthrographies performed on 59 patients with symptomatic shoulders, an intra-articular injection was performed (30 cases using the anterior approach and 30 using the posterior approach). Procedure-related pain was assessed by using a 5 score visual analogue scale (VAS). Depth of the puncture and standardized depth of puncture by body mass index (BMI) were recorded. The contrast leakage along the course of the puncture was evaluated by reviewing the MR. The statistical analyses included the Mann-Whitney U and Kruskal-Wallis test. There was no significant difference in VAS scores between the anterior and posterior groups (1.77 ± 1.10 vs. 1.80 ± 0.96). Depth of puncture and standardized depth of puncture by BMI were significantly shorter in the posterior group than those in the anterior group (4.4 ± 0.8 cm and 1.8 ± 0.3 cm vs. 6.6 ± 0.9 cm and 2.8 ± 0.4 cm, p < 0.001), respectively. The incidence of contrast leakage was more frequent in the posterior group (p = 0.003). The posterior approach will be useful in shoulder MR arthrography with a suspected anterior pathology, a postoperative follow-up study or obese patient.

  12. Fluoroscopically Guided Transcervical Fallopian Tube Recanalization of Post-Sterilization Reversal Mid-Tubal Obstructions

    International Nuclear Information System (INIS)

    Houston, J. Graeme; Anderson, David; Mills, John; Harrold, Anthony

    2000-01-01

    Purpose: To assess the technical success and early outcome of fluoroscopically guided transcervical fallopian tube recanalization (FTR) in mid-tubal occlusion following sterilization reversal surgery.Methods: From July 1995 to January 1998, patients with greater than 12 months secondary infertility underwent hysterosalpingography (HSG). FTR was performed in proximal or mid-tubal occlusion. Cases of FTR in mid-tubal occlusion were included in this study. Technical success (defined as complete tubal patency) using a standard guidewire and hydrophilic glidewire, the number of patients with at least one patent tube, and the intrauterine and ectopic pregnancy rates were determined.Results: Twenty-six infertile patients with previous sterilization reversal underwent HSG. Eight of 26 (31%) patients (mean age 32 years, range 23-37 years), had attempted FTR for mid-tubal occlusion at the site of surgical anastomosis. Fourteen tubes were attempted as there were two previous salpingectomies. Technical success was achieved in eight of 14 (57%) tubes attempted, resulting in five of eight (62%) patients having at least one patent tube. At follow-up (mean 18 months, range 12-28 months) in these five patients there was one intrauterine pregnancy. There were no ectopic pregnancies.Conclusions: FTR in mid-tubal obstruction in infertile patients following sterilization reversal surgery is technically feasible and may result in intrauterine pregnancy. In this small group there was a lower technical success rate and lower pregnancy rate than in unselected proximal tubal occlusion

  13. Identification and dose assessment of irradiated cardamom and cloves by EPR spectrometry

    International Nuclear Information System (INIS)

    Beshir, W.B.

    2014-01-01

    The use of electron paramagnetic resonance spectroscopy to accurately distinguish irradiated from unirradiated cardamom and cloves and assesses the absorbed dose to radiation processed cardamom and cloves are examined. The results were successful for identifying both irradiated and unirradiated cardamom and cloves. Additive reirradiation of cardamom and cloves produces reproducible dose–response functions, which can be used to assess the initial dose by back-extrapolation. Third degree polynomial function was used to fit the EPR signal/dose curves. It was found that this 3rd degree polynomial function provides satisfactory results without correction of decay for free radicals. The stability of the radiation induced EPR signal of irradiated cardamom and cloves were studied over a storage period of almost 8 months. The calculated G-value (The number of radicals per 100 eV of absorbed energy) for cardamom and cloves was found 0.07±0.01 and 0.055±0.01, respectively. - Highlights: • The EPR analysis of cardamom and cloves prove the sample has been irradiated or not. • Dose additive can be used for evaluation of the absorbed dose in cardamom and cloves. • The 3rd polynomial function can be used to fit the data and the estimated dose. • The stability of the radiation induced EPR signal of irradiated cardamom and cloves were studied over 2 months

  14. Effect of Low-Dose MDCT and Iterative Reconstruction on Trabecular Bone Microstructure Assessment.

    Science.gov (United States)

    Kopp, Felix K; Holzapfel, Konstantin; Baum, Thomas; Nasirudin, Radin A; Mei, Kai; Garcia, Eduardo G; Burgkart, Rainer; Rummeny, Ernst J; Kirschke, Jan S; Noël, Peter B

    2016-01-01

    We investigated the effects of low-dose multi detector computed tomography (MDCT) in combination with statistical iterative reconstruction algorithms on trabecular bone microstructure parameters. Twelve donated vertebrae were scanned with the routine radiation exposure used in our department (standard-dose) and a low-dose protocol. Reconstructions were performed with filtered backprojection (FBP) and maximum-likelihood based statistical iterative reconstruction (SIR). Trabecular bone microstructure parameters were assessed and statistically compared for each reconstruction. Moreover, fracture loads of the vertebrae were biomechanically determined and correlated to the assessed microstructure parameters. Trabecular bone microstructure parameters based on low-dose MDCT and SIR significantly correlated with vertebral bone strength. There was no significant difference between microstructure parameters calculated on low-dose SIR and standard-dose FBP images. However, the results revealed a strong dependency on the regularization strength applied during SIR. It was observed that stronger regularization might corrupt the microstructure analysis, because the trabecular structure is a very small detail that might get lost during the regularization process. As a consequence, the introduction of SIR for trabecular bone microstructure analysis requires a specific optimization of the regularization parameters. Moreover, in comparison to other approaches, superior noise-resolution trade-offs can be found with the proposed methods.

  15. Food-chain and dose model, CALDOS, for assessing Canada's Nuclear Fuel Waste Management concept

    International Nuclear Information System (INIS)

    Zach, R.; Sheppard, S.C.

    1991-01-01

    The food-chain and dose model, CALculation of DOSe (CALDOS), was developed for assessing Canada's concept for nuclear fuel waste disposal in a vault deep in crystalline rock of the Canadian Shield. The model is very general and based on the Shield as a whole. The critical group is totally self-sufficient and represented by ICRP (1975) Reference Man for dose prediction. CALDOS assumes steady-state conditions and deals with variation and uncertainty through Monte Carlo simulation techniques. Ingrowth of some radioactive daughters is considered during food-chain transfer. A limit is set on root uptake to avoid unrealistic plant concentrations. Integrated ingestion and inhalation rates of man are calculated in a unique way, based on energy needs. Soil ingestion by man and external exposure from building material are unique pathways considered. Tritium, 129 I, and 222 Rn are treated through special models, and 14 C and 129 I involve unique geosphere dose limits. All transfer coefficients are lognormally distributed, and the plant/soil concentration ratio is correlated with the soil partition coefficient. Animals' ingestion rates are normally distributed and correlated with each other. Comprehensive sets of internal and external dose conversion factors were calculated for CALDOS. Sample calculations show that dose distributions tend to be strongly right-skewed. Many features of CALDOS are relevant for environmental assessment in general

  16. Quantifying remarks to the question of uncertainties of the 'general dose assessment fundamentals'

    International Nuclear Information System (INIS)

    Brenk, H.D.; Vogt, K.J.

    1982-12-01

    Dose prediction models are always subject to uncertainties due to a number of factors including deficiencies in the model structure and uncertainties of the model input parameter values. In lieu of validation experiments the evaluation of these uncertainties is restricted to scientific judgement. Several attempts have been made in the literature to evaluate the uncertainties of the current dose assessment models resulting from uncertainties of the model input parameter values using stochastic approaches. Less attention, however, has been paid to potential sources of systematic over- and underestimations of the predicted doses due to deficiencies in the model structure. The present study addresses this aspect with regard to dose assessment models currently used for regulatory purposes. The influence of a number of basic simplifications and conservative assumptions has been investigated. Our systematic approach is exemplified by a comparison of doses evaluated on the basis of the regulatory guide model and a more realistic model respectively. This is done for 3 critical exposure pathways. As a result of this comparison it can be concluded that the currently used regularoty-type models include significant safety factors resulting in a systematic overprediction of dose to man up to two orders of magnitude. For this reason there are some indications that these models usually more than compensate the bulk of the stochastic uncertainties caused by the variability of the input parameter values. (orig.) [de

  17. Dental radiography: tooth enamel EPR dose assessment from Rando phantom measurements

    International Nuclear Information System (INIS)

    Aragno, D.; Fattibene, P.; Onori, S.

    2000-01-01

    Electron paramagnetic resonance dosimetry of tooth enamel is now established as a suitable method for individual dose reconstruction following radiation accidents. The accuracy of the method is limited by some confounding factors, among which is the dose received due to medical x-ray irradiation. In the present paper the EPR response of tooth enamel to endoral examination was experimentally evaluated using an anthropomorphic phantom. The dose to enamel for a single exposure of a typical dental examination performed with a new x-ray generation unit working at 65 kVp gave rise to a CO 2 -signal of intensity similar to that induced by a dose of about 2 mGy of 60 Co. EPR measurements were performed on the entire tooth with no attempt to separate buccal and lingual components. Also the dose to enamel for an orthopantomography exam was estimated. It was derived from TLD measurements as equivalent to 0.2 mGy of 60 Co. In view of application to risk assessment analysis, in the present work the value for the ratio of the reference dose at the phantom surface measured with TLD to the dose at the tooth measured with EPR was determined. (author)

  18. Dose assessment following an overexposure of a worker at a Swiss nuclear power plant.

    Science.gov (United States)

    Bailat, Claude J; Laedermann, Jean-Pascal; Baechler, Sébastien; Desorgher, Laurent; Aroua, Abbas; Bochud, François O

    2017-12-01

    The aim of this work was to assess the doses received by a diver exposed to a radiation source during maintenance work in the fuel transfer pool at a Swiss nuclear power plant, and to define whether the statutory limit was breached or not. Onsite measurements were carried out and different scenarios were simulated using the MicroShield Software and the MCNPX Monte Carlo radiation transport code to estimate the activity of the irradiating object as well as the doses to the limbs and the effective dose delivered to the operator. The activity of the object was estimated to 1.8 TBq. From the various dose estimations, a conservative value of 7.5 Sv was proposed for the equivalent dose to the skin on the hands and an effective dose of 28 mSv. The use of different experimental and calculation methods allowed us to accurately estimate the activity of the object and the dose delivered to the diver, useful information for making a decision on the most appropriate scheme of follow up for the patient.

  19. Preclinical assessment of HIV vaccines and microbicides by repeated low-dose virus challenges.

    Directory of Open Access Journals (Sweden)

    Roland R Regoes

    2005-08-01

    Full Text Available Trials in macaque models play an essential role in the evaluation of biomedical interventions that aim to prevent HIV infection, such as vaccines, microbicides, and systemic chemoprophylaxis. These trials are usually conducted with very high virus challenge doses that result in infection with certainty. However, these high challenge doses do not realistically reflect the low probability of HIV transmission in humans, and thus may rule out preventive interventions that could protect against "real life" exposures. The belief that experiments involving realistically low challenge doses require large numbers of animals has so far prevented the development of alternatives to using high challenge doses.Using statistical power analysis, we investigate how many animals would be needed to conduct preclinical trials using low virus challenge doses. We show that experimental designs in which animals are repeatedly challenged with low doses do not require unfeasibly large numbers of animals to assess vaccine or microbicide success.Preclinical trials using repeated low-dose challenges represent a promising alternative approach to identify potential preventive interventions.

  20. Landscape dose conversion factors used in the safety assessment SR-Site

    International Nuclear Information System (INIS)

    Avila, Rodolfo; Ekstroem, Per-Anders; Aastrand, Per-Gustav

    2010-12-01

    In this report two types of Dose Conversion Factors have been derived: i) a Landscape Dose Conversion Factor (LDF) that is applicable to continuous long-term releases to the biosphere at a constant rate, and ii) a Landscape Dose Conversion Factor for pulse releases (LDF pulse) that is applicable to a radionuclide release that reaches the biosphere in a pulse within years to hundreds of years. In SR-Site these Dose Factors are multiplied with modelled release rates or pulse releases from the geosphere to obtain dose estimates used in assessment of compliance with the regulatory risk criterion. The LDFs were calculated for three different periods of the reference glacial cycle; a period of submerged conditions following the deglaciation, the temperate period, and a prolonged period of periglacial conditions. Additionally, LDFs were calculated for the global warming climate case. The LDF pulse was calculated only for temperate climate conditions. The LDF and LDF pulse can be considered as Best Estimate values, which can be used in calculations of Best Estimate values of doses to a representative individual of the most exposed group from potential releases from a future repository. A systematic analysis of the effects of system, model and parameter uncertainties on the LDFs has been carried out. This analysis has shown that the use of the derived LDF would lead to cautious or realistic dose estimates. The models and methods that were used for derivation of the LDFs and LDF pulse are also described in this report

  1. Landscape dose conversion factors used in the safety assessment SR-Site

    Energy Technology Data Exchange (ETDEWEB)

    Avila, Rodolfo; Ekstroem, Per-Anders; Aastrand, Per-Gustav (Facilia AB (Sweden))

    2010-12-15

    In this report two types of Dose Conversion Factors have been derived: i) a Landscape Dose Conversion Factor (LDF) that is applicable to continuous long-term releases to the biosphere at a constant rate, and ii) a Landscape Dose Conversion Factor for pulse releases (LDF pulse) that is applicable to a radionuclide release that reaches the biosphere in a pulse within years to hundreds of years. In SR-Site these Dose Factors are multiplied with modelled release rates or pulse releases from the geosphere to obtain dose estimates used in assessment of compliance with the regulatory risk criterion. The LDFs were calculated for three different periods of the reference glacial cycle; a period of submerged conditions following the deglaciation, the temperate period, and a prolonged period of periglacial conditions. Additionally, LDFs were calculated for the global warming climate case. The LDF pulse was calculated only for temperate climate conditions. The LDF and LDF pulse can be considered as Best Estimate values, which can be used in calculations of Best Estimate values of doses to a representative individual of the most exposed group from potential releases from a future repository. A systematic analysis of the effects of system, model and parameter uncertainties on the LDFs has been carried out. This analysis has shown that the use of the derived LDF would lead to cautious or realistic dose estimates. The models and methods that were used for derivation of the LDFs and LDF pulse are also described in this report

  2. Dose, image quality and spine modeling assessment of biplanar EOS micro-dose radiographs for the follow-up of in-brace adolescent idiopathic scoliosis patients.

    Science.gov (United States)

    Morel, Baptiste; Moueddeb, Sonia; Blondiaux, Eleonore; Richard, Stephen; Bachy, Manon; Vialle, Raphael; Ducou