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Sample records for reference dose levels

  1. Patient dose with quality image under diagnostic reference levels

    International Nuclear Information System (INIS)

    Akula, Suresh Kumar; Singh, Gurvinder; Chougule, Arun

    2016-01-01

    Need to set Diagnostic Reference Level (DRL) for locations for all diagnostic procedures in local as compared to National. The review of DRL's should compare local with national or referenced averages and a note made of any significant variances to these averages and the justification for it. To survey and asses radiation doses to patient and reduce the redundancy in patient imaging to maintain DRLs

  2. Reference dose levels for dental periapical radiography in Chonnam Province

    International Nuclear Information System (INIS)

    Han, Mi Ra; Kang, Byung Cheol; Yoon, Suk Ja; Lee, Jae Seo; Kim, Young Hee

    2009-01-01

    To establish reference doses of periapical radiography in Chonnam Province, Korea. The target-skin distances were measured for dental patient's 1235 exposures including 345 mandibular molar areas. Each periapical radiation exposure was simulated with exactly the same patients exposure parameters and the simulated radiation doses were measured utilizing Mult-O-Meter (Unfors Instruments, Billadal, Sweden). The measurements were done in 44 dental clinics with 49 dental x-ray sets in Chonnam Province for one or two weeks at each dental clinic during year 2006. The third quartile patient surface doses were 2.8 mGy for overall periapical exposures and 3.2 mGy for periapical mandibular molar exposures. The third quartile patient surface doses in Chonnam Province can be used as a guide to accepted clinical practice to reduce patient radiation exposure for the surveyed reference doses were below the recommended dental periapical radiography dose of 7 mGy by IAEA.

  3. Reference dose levels for dental periapical radiography in Chonnam Province

    Energy Technology Data Exchange (ETDEWEB)

    Han, Mi Ra; Kang, Byung Cheol; Yoon, Suk Ja [Department of Oral and Maxillofacial Radiology, College of Dentistry, Dental Science Research Institute, Chonnam National University, Gwangju (Korea, Republic of); Lee, Jae Seo [Department of Oral and Maxillofacial Radiology, Chonnan National University Hospital, Gwangju (Korea, Republic of); Kim, Young Hee [Department of Oral and Maxillofacial Radiology, Hallym University Sacred Heart Hospital, Chuncheon (Korea, Republic of)

    2009-12-15

    To establish reference doses of periapical radiography in Chonnam Province, Korea. The target-skin distances were measured for dental patient's 1235 exposures including 345 mandibular molar areas. Each periapical radiation exposure was simulated with exactly the same patients exposure parameters and the simulated radiation doses were measured utilizing Mult-O-Meter (Unfors Instruments, Billadal, Sweden). The measurements were done in 44 dental clinics with 49 dental x-ray sets in Chonnam Province for one or two weeks at each dental clinic during year 2006. The third quartile patient surface doses were 2.8 mGy for overall periapical exposures and 3.2 mGy for periapical mandibular molar exposures. The third quartile patient surface doses in Chonnam Province can be used as a guide to accepted clinical practice to reduce patient radiation exposure for the surveyed reference doses were below the recommended dental periapical radiography dose of 7 mGy by IAEA.

  4. Establishment of dose reference levels for mammography in Greece

    International Nuclear Information System (INIS)

    Kalathaki, M.; Hourdakis, C.J.; Economides, S.; Tritakis, P.; Manousaridis, G.; Kalyvas, N.; Simantirakis, G.; Kipouros, P.; Kamenopoulou, V.

    2006-01-01

    Full text of publication follows: Diagnostic Reference Levels (D.R.L.) are dose levels established in medical practices for typical x-ray examinations concerning groups of standard size patients or standard phantoms and broadly defined types of equipment. When good and normal practice is performed, these levels are not expected to be exceeded. This work is an attempt to establish for the first time the D.R.L. for mammography in Greece. At present, there are 402 mammographic systems in clinical use all over the country. This study that lasted 3 years (2000-2003), includes 117 of these systems, 85% of which are installed in private and 15% in public sector countrywide. Measurements of entrance surface dose (E.S.D.) were performed as a part of the regular inspections performed by the Licensing and Inspections Department of Greek Atomic Energy Commission on the basis of the laboratories licensing procedure. Moreover, the entire performance of the mammographic units was assessed by quantitative and qualitative measurements of specific parameters. In order to establish the national D.R.L., a standard phantom was used during the quality control of the mammographic units and E.S.D. measurements were performed based on the clinical practice of each laboratory. The D.R.L. for this type of examination was established according to the 75. percentile of the E.S.D. curve and found equal to 7 mGy per single view. The comparison of this value with the one reported by the European Commission (10 mGy per view), indicates that the D.R.L. for mammography is lower in Greece. However, the primary concern of a mammographic examination is to keep breast dose as low as reasonably achievable while providing images with the maximum amount of diagnostic information. The quality of the produced images was therefore assessed for all systems examined, regardless of meeting or exceeding the quality criteria reference surface entrance dose. The results showed that the average total score of the

  5. Patient radiation doses and reference levels in pediatric interventional radiology

    Energy Technology Data Exchange (ETDEWEB)

    Habib Geryes, Bouchra; Lachaux, Julie; Boddaert, Nathalie; Brunelle, Francis [Hopital Universitaire Necker Enfants Malades, Department of Paediatric Radiology, Paris (France); Bak, Adeline; Ozanne, Augustin; Saliou, Guillaume [Hopital Bicetre, Hopitaux Universitaires Paris-Sud, Department of Neuroradiology, Le Kremlin Bicetre (France); Naggara, Olivier [Hopital Universitaire Necker Enfants Malades, Department of Paediatric Radiology, Paris (France); Centre Hospitalier Sainte-Anne, Universite Paris Descartes Sorbonne Paris Cite, Centre de Psychiatrie et Neurosciences, INSERM S894, DHU Neurovasculaire, Paris (France); Centre Hospitalier Sainte-Anne, Department of Neuroradiology, Universite Paris Descartes, Sorbonne Paris Cite, INSERM UMR894, Paris (France)

    2017-09-15

    To describe, in a multicentric paediatric population, reference levels (RLs) for three interventional radiological procedures. From January 2012 to March 2015, children scheduled for an interventional radiological procedure in two French tertiary centres were retrospectively included and divided into four groups according to age: children younger than 2 years (A1), aged 2-7 years (A5), 8-12 years (A10) and 13-18 years (A15). Three procedures were identified: cerebral digital subtraction angiography (DSA), brain arteriovenous malformation (bAVM) embolization, and head and neck superficial vascular malformation (SVM) percutaneous sclerotherapy. Demographic and dosimetric data, including dose area product (DAP), were collected. 550 procedures were included. For DSA (162 procedures), the proposed RL values in DAP were 4, 18, 12 and 32 Gy.cm{sup 2} in groups A1, A5, A10 and A15, respectively. For bAVM embolization (258 procedures), values were 33, 70, 105 and 88 Gy.cm{sup 2} in groups A1, A5, A10 and A15, respectively. For SVM sclerotherapy (130 procedures), values were 350, 790, 490 and 248 mGy.cm{sup 2} in groups A1, A5, A10 and A15, respectively. Consecutive data were available to permit a proposal of reference levels for three major paediatric interventional radiology procedures. (orig.)

  6. A CONCEPTUAL FRAMEWORK FOR MANAGING RADIATION DOSE TO PATIENTS IN DIAGNOSTIC RADIOLOGY USING REFERENCE DOSE LEVELS.

    Science.gov (United States)

    Almén, Anja; Båth, Magnus

    2016-06-01

    The overall aim of the present work was to develop a conceptual framework for managing radiation dose in diagnostic radiology with the intention to support optimisation. An optimisation process was first derived. The framework for managing radiation dose, based on the derived optimisation process, was then outlined. The outset of the optimisation process is four stages: providing equipment, establishing methodology, performing examinations and ensuring quality. The optimisation process comprises a series of activities and actions at these stages. The current system of diagnostic reference levels is an activity in the last stage, ensuring quality. The system becomes a reactive activity only to a certain extent engaging the core activity in the radiology department, performing examinations. Three reference dose levels-possible, expected and established-were assigned to the three stages in the optimisation process, excluding ensuring quality. A reasonably achievable dose range is also derived, indicating an acceptable deviation from the established dose level. A reasonable radiation dose for a single patient is within this range. The suggested framework for managing radiation dose should be regarded as one part of the optimisation process. The optimisation process constitutes a variety of complementary activities, where managing radiation dose is only one part. This emphasises the need to take a holistic approach integrating the optimisation process in different clinical activities. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. A conceptual framework for managing radiation dose to patients in diagnostic radiology using reference dose levels

    International Nuclear Information System (INIS)

    Almen, Anja; Baath, Magnus

    2016-01-01

    The overall aim of the present work was to develop a conceptual framework for managing radiation dose in diagnostic radiology with the intention to support optimisation. An optimisation process was first derived. The framework for managing radiation dose, based on the derived optimisation process, was then outlined. The outset of the optimisation process is four stages: providing equipment, establishing methodology, performing examinations and ensuring quality. The optimisation process comprises a series of activities and actions at these stages. The current system of diagnostic reference levels is an activity in the last stage, ensuring quality. The system becomes a reactive activity only to a certain extent engaging the core activity in the radiology department, performing examinations. Three reference dose levels-possible, expected and established-were assigned to the three stages in the optimisation process, excluding ensuring quality. A reasonably achievable dose range is also derived, indicating an acceptable deviation from the established dose level. A reasonable radiation dose for a single patient is within this range. The suggested framework for managing radiation dose should be regarded as one part of the optimisation process. The optimisation process constitutes a variety of complementary activities, where managing radiation dose is only one part. This emphasises the need to take a holistic approach integrating the optimisation process in different clinical activities. (authors)

  8. Reference dose levels for dental panoramic radiography in Anyang City

    International Nuclear Information System (INIS)

    Han, Mi Ra; Kang, Byung Cheol; Yoon, Suk Ja; Lee, Jae Seo; Kim, Young Hee

    2009-01-01

    To measure dose-width product (DWP) values used for dental panoramic radiography in Anyang city, Korea. Thirty-six panoramic dental radiographic sets (17 analogue panoramic sets and 19 digital panoramic sets) in 36 dental clinics in Anyang city were included in the study. Each patient's panoramic exposure parameters were simulated and the panoramic radiation doses were measured at the secondary collimator using a Mult-O-Meter (Unfors Instruments, Billdal, Sweden) at each dental clinic during 2006. The third quartile DWP was determined from 310 surface dose measurements on adult. The third quartile DWP for adult panoramic radiograph was 106.7 mGy mm. For analogue and digital panoramic radiograph, 3/4 DWP were 116.8 mGy mm and 72 mGy mm respectively. The overall third quartile DWP of panoramic radiography was 106.7 mGy mm. The measured 3/4 DWPs were higher than the 3/4 DWP of 65 mGy mm recommended by NRPB. Dentists who are operating above the reference dose should lower their panoramic exposure doses below the recommended reference value by changing the exposure parameters and/or their panoramic equipment.

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  10. The establishment and use of dose reference levels in general paediatric radiology

    International Nuclear Information System (INIS)

    Marsden, P.J.; Hardwick, J.; Mencik, C.; McLaren, C.; Young, C.; Mashford, P.

    2001-01-01

    Diagnostic reference levels for general paediatric radiology have been established in terms of delivered exposure parameters rather than skin dose or dose-area product. With supporting measurements from equipment quality assurance and assumptions of standard patient sizes it was possible to derive reference levels in terms of entrance surface dose. This allowed comparison to be made with other published data. The reference levels for common examinations are presented for different age bands. There is a notable variation with patient age for some examinations which is not apparent in other published data. (author)

  11. The need for national diagnostic reference levels: entrance surface dose measurement in intraoral radiography

    International Nuclear Information System (INIS)

    Mortazavi, S. M. J.; Shareghi, A.; Kavousi, A.; Ghiassi-Nejad, M.; Jafari-Zadeh, M.; Nazeri, F.; Mozdarani, H.

    2004-01-01

    Background: Intraoral radiographies are the most frequent X-ray examinations in humans. According to International Commission on Radiation Protection recommendations, the selection of a diagnostic reference level should be specific to a country or region. Critical organs such as thyroid gland are exposed to X-rays in intraoral radiography and these exposures should be kept as low as reasonably achievable. To assist the development of DRLs for intraoral radiography, a National Radiation Protection Department-sponsored pilot study was carried out. Materials and methods: thermoluminescent dosimetry is widely acknowledged to be the recommended method for measuring entrance surface doses. In this study, entrance surface doses was measured using LiF thermoluminescent dosimeters on the skin (either mandibular or maxillary arcs) of 40 patients. Three thermoluminescent dosimetry chips were placed on the skin of each patient. The doses were averaged for each radiography and mean entrance surface doses of all patients calculated. Results: the mean ±SD entrance surface dose at the center of the beam on the patient's skin in intraoral radiography was 1.173 ±0.606 mGy (ranged from 0.01 o 0.40 m Gy). The mean entrance surface doses for male and female patients were 1.380± 0.823, and 1.004± 0.258 respectively. No statistically significant difference was found between these means. Despite its necessity , in national level , there is no published data on the diagnostic reference levels for intraoral radiography. However, the results obtained in this study are lower than those reported by investigators in other countries. Conclusion: in IR Iran , due to lack of large scale studies, no diagnostic reference levels have been set for X-ray diagnostic procedures. Due to lack of national diagnostic reference levels, it is not possible to clarify whether in intraoral radiographies any dose reduction techniques are needed. We intend to perform similar nationwide studies to set the

  12. Reference dose levels for dental panoramic radiography in Gwangju (South Korea)

    International Nuclear Information System (INIS)

    Lee, J. S.; Kim, Y. H.; Yoon, S. J.; Kang, B. C.

    2010-01-01

    This study assessed the reference dose levels for dental panoramic radiography in Gwangju city (South Korea) based on the dose width product (DWP) and compared them with those already established elsewhere. A total of 44 panoramic dental radiographic sets (36 digital and 8 analogue panoramic sets) in 41 dental clinics in Gwangju city were chosen. The third quartile DWP was determined from 429 surface dose measurements of the adult surface dose in panoramic dental radiography. The third quartile DWP for panoramic radiography was 60.1 mGy mm. The proposed DWP reference levels of 60.1 mGy mm were less than or equal to those previously reported in other countries, such as Italy and UK, and acceptable for panoramic radiography in Gwangju (KR). (authors)

  13. The impact of diagnostic reference levels on patient doses from X-ray examinations

    International Nuclear Information System (INIS)

    Leitz, W.; Almen, A.

    2008-01-01

    The aim of this study was to evaluate the effect of diagnostic reference levels (DRL). For this study patient doses for the years 1999 and 2006 were available. Patient doses on a national level for eleven specified X-ray examinations were assessed. For the conventional examinations DRL have been used after the first survey in 1999, for computed tomography no DRL were used and for mammography DRL have been used for more than 20 years. Whereas the patient doses for conventional examinations were 30% lower in 2006 compared to 1999 the doses remained essentially the same for computed tomography and mammography. The widths of the dose distributions had only slightly decreased for conventional examinations and remained the same for computed tomography and mammography. This study has shown that after implementation of DRL a considerable dose reduction can be expected. Practices exceeding DRL will perform remedial actions with the aim to reduce dose, as demonstrated for the conventional examinations. Despite the fact that practices for computed tomography could compare doses with others practices, in the absence of DRL no actions to reduce doses were performed. The margin for further dose reductions in mammography is small due to the long term use of DRL. The impact of DRL on patient doses is changing with time. When introduced large dose reductions can be expected. After long term use DRL will counteract the introduction of new technique with unjustified high patient doses. Despite the merits in terms of dose saving it must be recognized that DRL has its limits - it has to be amended with other radiological protection activities. Other means and measures have to be developed, for example by the authorities, in order to ensure that optimisation is continued even when the patient doses are below the DRL. (author)

  14. Regional Diagnostic Reference Levels and Collective Effective Doses from Computed Tomography (CT) Scanners in India

    International Nuclear Information System (INIS)

    Livingstone, R.S.; Dinakaran, P.M.

    2011-01-01

    Diagnostic examinations performed using computed tomography (CT) are on the increase, and the use of this modality needs to be monitored periodically. The aim of this study was to formulate regional diagnostic reference levels (DRLs) and assess collective effective doses from CT scanners in Tamil Nadu, India. In-site CT dose measurements were performed for 127 CT scanners in Tamil Nadu as a part of the Atomic Energy Regulatory Board (AERB) funded project for a period of two years. Regional DRLs were formulated at third quartile level for three CT protocols such as thorax, abdomen and pelvis and were found to be 557 mGy.cm, 521 mGy.cm and 294 mGy.cm, respectively. The collective effective dose in Tamil Nadu was found to be 14.93 man Sv per day. (author)

  15. Estimating the population dose from nuclear medicine examinations towards establishing diagnostic reference levels

    International Nuclear Information System (INIS)

    Niksirat, Fatemeh; Monfared, Ali Shabestani; Deevband, Mohammad Reza; Amiri, Mehrangiz; Gholami, Amir

    2016-01-01

    This study conducted a review on nuclear medicine (NM) services in Mazandaran Province with a view to establish adult diagnostic reference levels (DRLs) and provide updated data on population radiation exposure resulting from diagnostic NM procedures. The data were collected from all centers in all cities of Mazandaran Province in the North of Iran from March 2014 to February 2015. The 75 th percentile of the distribution and the average administered activity (AAA) were calculated and the average effective dose per examination, collective effective dose to the population and annual effective dose per capita were estimated using dose conversion factors. The gathered data were analyzed via SPSS (version 18) software using descriptive statistics. Based on the data of this study, the collective effective dose was 95.628 manSv, leading to a mean effective dose of 0.03 mSv per capita. It was also observed that the myocardial perfusion was the most common procedure (50%). The 75 th percentile of the distribution of administered activity (AA) represents the DRL. The AAA and the 75 th percentile of the distribution of AA are slightly higher than DRL of most European countries. Myocardial perfusion is responsible for most of the collective effective dose and it is better to establish national DRLs for myocardial perfusion and review some DRL values through the participation of NM specialists in the future

  16. Dose limits, constraints, reference levels. What does it mean for radiation protection?

    International Nuclear Information System (INIS)

    Breckow, J.

    2016-01-01

    The established concept of radiation protection with its basic principles justification, optimization, and limitation has proved its value and is going to be continued. In its deeper meaning, however, the concept is rather subtle and complex. Furthermore, in some aspects there remain some breaches or inconsistencies. This is just true for the terms dose limit, reference lever, and constraint that are tightly associated with the radiation protection principles. In order to guarantee the ability of radiation protection in whole extent, the subtle differences of meaning have to be communicated. There is a permanent need to defend the conceptual function of these terms against deliberate or undeliberate misinterpretations. Reference levels are definitely not the same as dose limits and they may not be misused as such. Any attempt to misinterpret fundamental radiation protection principles for selfish purposes should discouraged vigorously.

  17. Alanine dosimetry at NPL - the development of a mailed reference dosimetry service at radiotherapy dose levels

    International Nuclear Information System (INIS)

    Sharpe, P.H.G.; Sephton, J.P.

    1999-01-01

    In this paper we describe the work that has been carried out at National Physical Laboratory (NPL) to develop a mailed alanine reference dosimetry service for radiotherapy dose levels. The service is based on alanine/paraffin wax dosimeters produced at NPL. Using a data analysis technique based on spectrum fitting, it has been possible to achieve a precision of dose measurement better than ±0.05 Gy (1σ). A phantom set has been developed for use in high energy photon beams, which enables simultaneous irradiation of alanine dosimeters and ionisation chambers in a well defined geometry. Studies in photon beams of energies between 60 Co and 20 MeV have shown no significant energy dependence (<1%) for alanine relative to dose determination using a graphite calorimeter. Work is underway to extend the service to electron beams, and preliminary results are presented on the direct calibration of alanine in electron beams using a graphite calorimeter. (author)

  18. Dose evaluation and establishment of reference levels in activity for nuclear medicine

    International Nuclear Information System (INIS)

    Ribeiro, Julio Cesar de Souza

    2017-01-01

    The International Commission on Radiation Protection (ICRP) has emphasized the importance of accurately determining the mean dose levels, or administered activity, received by the patients for each medical procedure that uses ionizing radiation. However, the number of bibliographic references addressing the need to know and optimize these levels is insufficient, or rather limited, which may lead to non-standardizes techniques, a lack of exposures control, and also the increase of associated radiological risks of these procedures. In this context, a software in Visual Basic® of Microsoft© language was developed whose function is to elaborate a method of obtaining the Reference Levels in Activity (RLA) for nuclear medicine patients by determining the third quartile of the examinations carried out. The program also allows obtaining absorbed dose values in critical organs based on patient specificities as age, sex and Body Mass Index (BMI) in order to evaluate the risk involved in each procedure. The main nuclear medicine diagnostic procedures were evaluated through the database of two public hospitals and a private clinic, obtaining the NRAs of each facility, where the software was validated by comparison with the traditionally accepted calculation methods. Due to the results obtained in each installation, in addition to NRA determination, gaps in treatment capacities and unjustified dose variations for the same procedure were identified, indicating the need for optimization. Thus, the developed program is able to provide the estimated values of effective and absorbed doses involved in each procedure, for each patient, providing reference values for nuclear medicine field, not available in the national scenario so far. (author)

  19. 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)

  20. The role and impact of reference doses on diagnostic radiology, how to use them at the national level?

    International Nuclear Information System (INIS)

    Nikodemova, D.; Horvathova, M.; Karkus, R.

    2003-01-01

    Results of patient dose audits reported in this paper for several types of examinations and various technical units have shown the importance of applications of reference dose levels in radiological practice. On the basis of national surveys slightly lower or higher standard dose reference levels (DRL) values could be justified. Continuing revision of DRL values and their extension to other types of radiographic and fluoroscopic examinations is needed

  1. Patient doses in CT examinations in Switzerland: Implementation of national diagnostic reference levels

    International Nuclear Information System (INIS)

    Treier, R.; Aroua, A.; Verdun, F. R.; Samara, E.; Stuessi, A.; Trueb, P. R.

    2010-01-01

    Diagnostic reference levels (DRLs) were established for 21 indication-based CT examinations for adults in Switzerland. One hundred and seventy-nine of 225 computed tomography (CT) scanners operated in hospitals and private radiology institutes were audited on-site and patient doses were collected. For each CT scanner, a correction factor was calculated expressing the deviation of the measured weighted computed tomography dose index (CTDI) to the nominal weighted CTDI as displayed on the workstation. Patient doses were corrected by this factor providing a realistic basis for establishing national DRLs. Results showed large variations in doses between different radiology departments in Switzerland, especially for examinations of the petrous bone, pelvis, lower limbs and heart. This indicates that the concept of DRLs has not yet been correctly applied for CT examinations in clinical routine. A close collaboration of all stakeholders is mandatory to assure an effective radiation protection of patients. On-site audits will be intensified to further establish the concept of DRLs in Switzerland. (authors)

  2. Establishment of computed tomography reference dose levels in Onassis Cardiac Surgery Center

    International Nuclear Information System (INIS)

    Tsapaki, V.; Kyrozi, E.; Syrigou, T.; Mastorakou, I.; Kottou, S.

    2001-01-01

    The purpose of the study was to apply European Commission (EC) Reference Dose Levels (RDL) in Computed Tomography (CT) examinations at Onassis Cardiac Surgery Center (OCSC). These are weighted CT Dose Index (CTDI w ) for a single slice and Dose-Length Product (DLP) for a complete examination. During the period 1998-1999, the total number of CT examinations, every type of CT examination, patient related data and technical parameters of the examinations were recorded. The most frequent examinations were chosen for investigation which were the head, chest, abdomen and pelvis. CTDI measurements were performed and CTDI w and DLP were calculated. Third Quartile values of CTDI w were chosen to be 43mGy for head, 8mGy for chest, and 22mGy for abdomen and pelvis examinations. Third quartile values of DLP were chosen to be 740mGycm for head, 370mGycm for chest, 490mGycm for abdomen and 420mGycm for pelvis examination. Results confirm that OCSC follows successfully the proposed RDL for the head, chest, abdomen and pelvis examinations in terms of radiation dose. (author)

  3. Establishment of institutional diagnostic reference level for computed tomography with automated dose-tracking software.

    Science.gov (United States)

    Liang, Chong R; Chen, Priscilla X H; Kapur, Jeevesh; Ong, Michael K L; Quek, Swee T; Kapur, Subhash C

    2017-06-01

    The aim of this study was to establish institutional diagnostic reference levels (DRLs) by summarising doses collected across the five computed tomography (CT) system in our institution. CT dose data of 15940 patients were collected retrospectively from May 2015 to October 2015 in five institutional scanners. The mean, 75th percentile and 90th percentile of the dose spread were calculated according to anatomic region. The common CT examinations such as head, chest, combined abdomen/pelvis (A/P), and combined chest/abdomen/pelvis (C/A/P) were reviewed. Distribution of CT dose index (CTDIvol), dose-length product (DLP) and effective dose (ED) were extracted from the data for single-phasic and multiphasic examinations. The institutional DRL for our CT units were established as mean (50th percentile) of CTDIvol (mGy), DLP (mGy.cm) and ED (mSv) for single and multiphasic studies using the dose-tracking software. In single phasic examination, Head: (49.0 mGy), (978.0 mGy.cm), (2.4 mSv) respectively; Chest: (6.0 mGy), (254.0 mGy.cm), (4.9 mSv) respectively; CT A/P (10.0 mGy), (514.0 mGy.cm), (8.9 mSv) respectively; CT C/A/P (10.0 mGy), (674.0 mGy.cm), (11.8 mSv) respectively. In multiphasic studies: Head (45.0 mGy), (1822.0 mGy.cm), (5.0 mSv) respectively; Chest (8.0 mGy), (577.0 mGy.cm), (10.0 mSv) respectively; CT A/P: (10.0 mGy), (1153.0 mGy.cm), (20.2 mSv) respectively; CT C/A/P: (11.0 mGy), (1090.0 mGy.cm), (19.2 mSv) respectively. The reported metrics offer a variety of information that institutions can use for quality improvement activities. The variations in dose between scanners suggest a large potential for optimisation of radiation dose. © 2017 The Authors. Journal of Medical Radiation Sciences published by John Wiley & Sons Australia, Ltd on behalf of Australian Society of Medical Imaging and Radiation Therapy and New Zealand Institute of Medical Radiation Technology.

  4. Developing patient-specific dose protocols for a CT scanner and exam using diagnostic reference levels

    International Nuclear Information System (INIS)

    Strauss, Keith J.

    2014-01-01

    The management of image quality and radiation dose during pediatric CT scanning is dependent on how well one manages the radiographic techniques as a function of the type of exam, type of CT scanner, and patient size. The CT scanner's display of expected CT dose index volume (CTDI vol ) after the projection scan provides the operator with a powerful tool prior to the patient scan to identify and manage appropriate CT techniques, provided the department has established appropriate diagnostic reference levels (DRLs). This paper provides a step-by-step process that allows the development of DRLs as a function of type of exam, of actual patient size and of the individual radiation output of each CT scanner in a department. Abdomen, pelvis, thorax and head scans are addressed. Patient sizes from newborns to large adults are discussed. The method addresses every CT scanner regardless of vendor, model or vintage. We cover adjustments to techniques to manage the impact of iterative reconstruction and provide a method to handle all available voltages other than 120 kV. This level of management of CT techniques is necessary to properly monitor radiation dose and image quality during pediatric CT scans. (orig.)

  5. Diagnostic Reference Levels for Patient Radiation Doses in Pelvis and Lumbar spine Radiography in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kwang Yong; Lee, Byung Young; Lee, Jung Eun; Lee, Hyun Koo; Jung, Seunbg Hwan; Kim, Byung Woo; Kim, Hyeog Ju; Kim, Dong Sup [Radiation Safety Division National Institute of Food and Drug Safety Evaluation, Seoul (Korea, Republic of)

    2009-12-15

    Pelvis and lumbar spine radiography, among various types of diagnostic radiography, include gonads of the human body and give patients high radiation dose. Nevertheless, diagnostic reference levels for patient radiation dose in pelvis and lumbar spine radiography has not yet been established in Korea. Therefore, the radiation dose that patients receive from pelvis and lumbar radiography is measured and the diagnostic reference level on patient radiation dose for the optimization of radiation protection of patients in pelvis and lumbar spine radiography was established. The conditions and diagnostic imaging information acquired during the time of the postero-anterior view of the pelvis and the postero-anterior and lateral view of the lumbar spine at 125 medical institutions throughout Korea are collected for analysis and the entrance surface dose received by patients is measured using a glass dosimeter. The diagnostic reference levels for patient radiation dose in pelvis and lumbar spine radiography to be recommended to the medical institutes is arranged by establishing the dose from the patient radiation dose that corresponds to the 3rd quartile values as the appropriate diagnostic reference level for patient radiation dose. According to the results of the assessment of diagnostic imaging information acquired from pelvis and lumbar spine radiography and the measurement of patient entrance surface dose taken at the 125 medical institutes throughout Korea, the tube voltage ranged between 60-97 kVp, with the average use being 75 kVp, and the tube current ranged between 8-123 mAs, with the average use being 30 mAs. In the posteroanterior and lateral views of lumbar spine radiography, the tube voltage of each view ranged between 65-100 kVp (average use: 78 kVp) and 70-109 kVp (average use: 87 kVp), respectively, and the tube current of each view ranged between 10-100 mAs(average use: 35 mAs) and between 8.9-300 mAs(average use: 64 mAs), respectively. The measurements of

  6. Diagnostic Reference Levels for Patient Radiation Doses in Pelvis and Lumbar spine Radiography in Korea

    International Nuclear Information System (INIS)

    Lee, Kwang Yong; Lee, Byung Young; Lee, Jung Eun; Lee, Hyun Koo; Jung, Seunbg Hwan; Kim, Byung Woo; Kim, Hyeog Ju; Kim, Dong Sup

    2009-01-01

    Pelvis and lumbar spine radiography, among various types of diagnostic radiography, include gonads of the human body and give patients high radiation dose. Nevertheless, diagnostic reference levels for patient radiation dose in pelvis and lumbar spine radiography has not yet been established in Korea. Therefore, the radiation dose that patients receive from pelvis and lumbar radiography is measured and the diagnostic reference level on patient radiation dose for the optimization of radiation protection of patients in pelvis and lumbar spine radiography was established. The conditions and diagnostic imaging information acquired during the time of the postero-anterior view of the pelvis and the postero-anterior and lateral view of the lumbar spine at 125 medical institutions throughout Korea are collected for analysis and the entrance surface dose received by patients is measured using a glass dosimeter. The diagnostic reference levels for patient radiation dose in pelvis and lumbar spine radiography to be recommended to the medical institutes is arranged by establishing the dose from the patient radiation dose that corresponds to the 3rd quartile values as the appropriate diagnostic reference level for patient radiation dose. According to the results of the assessment of diagnostic imaging information acquired from pelvis and lumbar spine radiography and the measurement of patient entrance surface dose taken at the 125 medical institutes throughout Korea, the tube voltage ranged between 60-97 kVp, with the average use being 75 kVp, and the tube current ranged between 8-123 mAs, with the average use being 30 mAs. In the posteroanterior and lateral views of lumbar spine radiography, the tube voltage of each view ranged between 65-100 kVp (average use: 78 kVp) and 70-109 kVp (average use: 87 kVp), respectively, and the tube current of each view ranged between 10-100 mAs(average use: 35 mAs) and between 8.9-300 mAs(average use: 64 mAs), respectively. The measurements of

  7. Determination of dose to patient in different teams of TC and assessment with international reference levels

    International Nuclear Information System (INIS)

    Ruiz Morales, C.; Fernandez lara, A. A.; Buades Forner, M. J.; Tobarra Gonzalez, B. M.

    2013-01-01

    The increase in CT studies and the differences observed between the different equipment used in our hospital prompted us to determine the doses to patients in different studies and check the results obtained with the reference values published internationally. (Author)

  8. Derivation of a reference dose and drinking water equivalent level for 1,2,3-trichloropropane.

    Science.gov (United States)

    Tardiff, Robert G; Carson, M Leigh

    2010-06-01

    In some US potable water supplies, 1,2,3-trichloropropane (TCP) has been present at ranges of non-detect to less than 100 ppb, resulting from past uses. In subchronic oral studies, TCP produced toxicity in kidneys, liver, and other tissues. TCP administered by corn oil gavage in chronic studies produced tumors at multiple sites in rats and mice; however, interpretation of these studies was impeded by substantial premature mortality. Drinking water equivalent levels (DWELs) were estimated for a lifetime of consumption by applying biologically-based safety/risk assessment approaches, including Monte Carlo techniques, and with consideration of kinetics and modes of action, to possibly replace default assumptions. Internationally recognized Frameworks for human relevance of animal data were employed to interpret the findings. Calculated were a reference dose (=39 microg/kg d) for non-cancer and Cancer Values (CV) (=10-14 microg/kg d) based on non-linear dose-response relationships for mutagenicity as a precursor of cancer. Lifetime Average Daily Intakes (LADI) are 3130 and 790-1120 microg/person-d for non-cancer and cancer, respectively. DWELs, estimated by applying a relative source contribution (RSC) of 50% to the LADIs, are 780 and 200-280 microg/L for non-cancer and cancer, respectively. These DWELs may inform establishment of formal/informal guidelines and standards to protect public health. Copyright 2010 Elsevier Ltd. All rights reserved.

  9. A comparison of the suitability of patient dosimetry methods for establishing diagnostic dose reference levels and optimisation strategies

    International Nuclear Information System (INIS)

    Gfirtner, Hans; Moores, B. Michael; Stieve, Friedrich E.

    2008-01-01

    For 50 adult patients referred for chest radiography, air kerma at the diaphragm KD, dose area product and entrance skin dose were measured. The air kerma at the diaphragm and the dose area product were determined using Diamentor M4KDK(PTW) which allows measuring air kerma and dose area product simultaneously. For the measurement of entrance skin dose TLDs are used. A 50% variation in dose, incident dose as well as entrance skin dose, was registered for the same patient thickness. The recommendation of ICRP to perform the measurements for DRLs at 'representative patients' and that of the CEC to use 'standard-sized patients' seem to make little sense in the case of chest radiography. It could be demonstrated, that the dose area product is the least appropriate dose quantity for patient measurements and to define dose reference levels. For some radiological examinations like chest, pelvis and lumbar spine the dose area product is even sex dependent. Incident dose and entrance surface dose are of equal quality for patient dose measurements in diagnostic radiography. (author)

  10. Establishment of national diagnostic reference level for renal doses in nuclear medicine departments at Khartoum-Sudan

    International Nuclear Information System (INIS)

    Alameen, Suhaib; Hamid, Alhadi; Rushdi, M. A. H.

    2016-01-01

    In this work we established a diagnostic reference level (DRL) for patient dose focusing on the investigation of activity to the kidneys during(99mTc-DTPA) kidney scan, selected two department nuclear medicine in main hospitals in Khartoum state. The DRLs is an investigational level used to identify unusually high radiation doses for common diagnostic medical in Nuclear Medicine procedures and suggested action levels above which a facility should review its methods and determine if acceptable image quality can be achieved at lower doses. The high specific activity of 99mTc makes it suitable as a first pass agent, for multiple or sequential studies, 99mTc diethylenetriaminepentaacetic acid (DTPA) is preferred to 99mTc-pertechnetate. Patients who had been prepared for the kidney scan 99mTc- DTPA were divided to three groups. The first group received dose less than 5 mCi, are represent (27.03%) from all patients, second group received dose 5 to 5.5 mCi are represent(66.67%) and the third group received dose from 5.6 to 6.2 mCi are represent (6.31%) from all patients 99mTc-DTPA. And according to the IAEA recommendation for adult doses(5-10mCi) this study show that about 93.1% of the sample examines by dose less than 5.5 mCi. The results presented will serve as a baseline data needed for deriving reference doses for renal examinations for nuclear medicine departments in Sudan.(Author)

  11. Diagnostic reference levels for common computed tomography (CT) examinations: results from the first Nigerian nationwide dose survey.

    Science.gov (United States)

    Ekpo, Ernest U; Adejoh, Thomas; Akwo, Judith D; Emeka, Owujekwe C; Modu, Ali A; Abba, Mohammed; Adesina, Kudirat A; Omiyi, David O; Chiegwu, Uche H

    2018-01-29

    To explore doses from common adult computed tomography (CT) examinations and propose national diagnostic reference levels (nDRLs) for Nigeria. This retrospective study was approved by the Nnamdi Azikiwe University and University Teaching Hospital Institutional Review Boards (IRB: NAUTH/CS/66/Vol8/84) and involved dose surveys of adult CT examinations across the six geographical regions of Nigeria and Abuja from January 2016 to August 2017. Dose data of adult head, chest and abdomen/pelvis CT examinations were extracted from patient folders. The median, 75th and 25th percentile CT dose index volume (CTDI vol ) and dose-length-product (DLP) were computed for each of these procedures. Effective doses (E) for these examinations were estimated using the k conversion factor as described in the ICRP publication 103 (E DLP  =  k × DLP ). The proposed 75th percentile CTDI vol for head, chest, and abdomen/pelvis are 61 mGy, 17 mGy, and 20 mGy, respectively. The corresponding DLPs are 1310 mGy.cm, 735 mGy.cm, and 1486 mGy.cm respectively. The effective doses were 2.75 mSv (head), 10.29 mSv (chest), and 22.29 mSv (abdomen/pelvis). Findings demonstrate wide dose variations within and across centres in Nigeria. The results also show CTDI vol comparable to international standards, but considerably higher DLP and effective doses.

  12. Evaluation of alanine as a reference dosimeter for therapy level dose comparisons in megavoltage electron beams

    International Nuclear Information System (INIS)

    McEwen, Malcolm; Sharpe, Peter; Voros, Sandor

    2015-01-01

    When comparing absorbed dose standards from different laboratories (e.g. National Measurement Institutes, NMIs, for Key or Supplementary comparisons) it is rarely possible to carry out a direct comparison of primary standard instruments, and therefore some form of transfer detector is required. Historically, air-filled, unsealed ionization chambers have been used because of the long history of using these instruments, very good stability over many years, and ease of transport. However, the use of ion chambers for therapy-level comparisons is not without its problems. Findings from recent investigations suggest that ion chambers are prone to non-random variations, they are not completely robust to standard courier practices, and failure at any step in a comparison can render all measurements potentially useless. An alternative approach is to identify a transfer system that is insensitive to some of these concerns - effectively a dosimeter that is inexpensive, simple to use, robust, but with sufficient precision and of a size relevant to the disseminated quantity in question. The alanine dosimetry system has been successfully used in a number of situations as an audit dosimeter and therefore the purpose of this investigation was to determine whether alanine could also be used as the transfer detector for dosimetric comparisons, which require a lower value for the measurement uncertainty. A measurement protocol was developed for comparing primary standards of absorbed dose to water in high-energy electron beams using alanine pellets irradiated in a water-equivalent plastic phantom. A trial comparison has been carried out between three NMIs and has indicated that alanine is a suitable alternative to ion chambers, with the system used achieving a precision of 0.1%. Although the focus of the evaluation was on the performance of the dosimeter, the comparison results are encouraging, showing agreement at the level of the combined uncertainties (∼0.6%). Based on this

  13. Evidence of dose saving in routine CT practice using iterative reconstruction derived from a national diagnostic reference level survey.

    Science.gov (United States)

    Thomas, P; Hayton, A; Beveridge, T; Marks, P; Wallace, A

    2015-09-01

    To assess the influence and significance of the use of iterative reconstruction (IR) algorithms on patient dose in CT in Australia. We examined survey data submitted to the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) National Diagnostic Reference Level Service (NDRLS) during 2013 and 2014. We compared median survey dose metrics with categorization by scan region and use of IR. The use of IR results in a reduction in volume CT dose index of between 17% and 44% and a reduction in dose-length product of between 14% and 34% depending on the specific scan region. The reduction was highly significant (p sum test) for all six scan regions included in the NDRLS. Overall, 69% (806/1167) of surveys included in the analysis used IR. The use of IR in CT is achieving dose savings of 20-30% in routine practice in Australia. IR appears to be widely used by participants in the ARPANSA NDRLS with approximately 70% of surveys submitted employing this technique. This study examines the impact of the use of IR on patient dose in CT on a national scale.

  14. Patient grouping for dose surveys and establishment of diagnostic reference levels in paediatric computed tomography

    International Nuclear Information System (INIS)

    Vassileva, J.; Rehani, M.

    2015-01-01

    There has been confusion in literature on whether paediatric patients should be grouped according to age, weight or other parameters when dealing with dose surveys. The present work aims to suggest a pragmatic approach to achieve reasonable accuracy for performing patient dose surveys in countries with limited resources. The analysis is based on a subset of data collected within the IAEA survey of paediatric computed tomography (CT) doses, involving 82 CT facilities from 32 countries in Asia, Europe, Africa and Latin America. Data for 6115 patients were collected, in 34.5 % of which data for weight were available. The present study suggests that using four age groups, <1, >1-5, >5-10 and >10-15 y, is realistic and pragmatic for dose surveys in less resource countries and for the establishment of DRLs. To ensure relevant accuracy of results, data for >30 patients in a particular age group should be collected if patient weight is not known. If a smaller sample is used, patient weight should be recorded and the median weight in the sample should be within 5-10 % from the median weight of the sample for which the DRLs were established. Comparison of results from different surveys should always be performed with caution, taking into consideration the way of grouping of paediatric patients. Dose results can be corrected for differences in patient weight/age group. (authors)

  15. Local patient dose diagnostic reference levels in pediatric interventional cardiology in Chile using age bands and patient weight values.

    Science.gov (United States)

    Ubeda, Carlos; Miranda, Patricia; Vano, Eliseo

    2015-02-01

    To present the results of a patient dose evaluation program in pediatric cardiology and propose local diagnostic reference levels (DRLs) for different types of procedure and age range, in addition to suggesting approaches to correlate patient dose values with patient weight. This study was the first conducted in Latin America for pediatric interventional cardiology under the auspices of the International Atomic Energy Agency. Over three years, the following data regarding demographic and patient dose values were collected: age, gender, weight, height, number of cine series, total number of cine frames, fluoroscopy time (FT), and two dosimetric quantities, dose-area product (DAP) and cumulative dose (CD), at the patient entrance reference point. The third quartile values for FT, DAP, CD, number of cine series, and the DAP/body weight ratio were proposed as the set of quantities to use as local DRLs. Five hundred and seventeen patients were divided into four age groups. Sample sizes by age group were 120 for bands used in Europe, complemented with the values of the ratio between DAP and patient weight. This permits a rough estimate of DRLs for different patient weights and the refining of these values for the age bands when there may be large differences in child size. These DRLs were obtained at the largest pediatric hospital in Chile, with an active optimization program, and could be used by other hospitals in the Latin America region to compare their current patient dose values and determine whether corrective action is appropriate. © 2015 American Association of Physicists in Medicine.

  16. Patient dose audit of the most frequent radiographic examinations and the proposed local diagnostic reference levels in southwestern Nigeria: Imperative for dose optimisation

    Directory of Open Access Journals (Sweden)

    N.N. Jibiri

    2016-07-01

    Full Text Available Diagnostic reference levels (DRLs is a veritable tool for dose optimisation and patient protection in diagnostic radiology. However, it is essential to have information on the local situation especially in a large hospital with several units or a cluster of healthcare centres within a geographical region with several X-ray units. In the present study, entrance surface doses (ESDs were measured in twelve (12 healthcare centres consisting of 15 radiological units using thermoluminescent dosimeters (TLDs. Seven radiological procedures such as; chest PA, abdomen AP, pelvis AP, lumbar spine AP, skull AP, knee AP, and hand AP frequently carried out in Nigeria were included in the study, and their local diagnostic reference levels (LDRLs were determined. The values of the determined LDRLs were compared with established NDRLs in UK, US, Slovenia, Italy and Brazil. The LDRLs determined in the two groups (healthcare centres studied ranged from 1.78 to 3.01, 2.71 to 2.84, 2.11 to 3.79, 3.93 to 8.79, 1.06 to 1.73 and 1.10 to 1.44 mGy for chest PA, pelvis AP, lumbar spine AP, skull AP, knee AP and hand AP respectively. Large variations were found among the X-ray units studied even within the same centre. Entrance surface doses obtained in pelvis AP and lumbar spine AP in both GROUP A and were found to be lower than the NRPB-HPA 2010 review for UK, while in all other five examinations, value of the measured entrance surface dose (ESD are higher than the doses reported in the UK review. The relative higher doses found in the study are attributable to higher tube load (mAs used and indicative of the need for dose optimisation in Nigerian radiological practice.

  17. Patient dose measurement in common medical X-ray examinations and propose the first local dose reference levels to diagnostic radiology in Iran

    Science.gov (United States)

    Rasuli, Behrouz; Tabari Juybari, Raheleh; Forouzi, Meysam; Ghorbani, Mohammad

    2017-09-01

    Introduction: The main purpose of this study was to investigate patient dose in pelvic and abdomen x-ray examinations. This work also provided the LDRLs (local diagnostic reference levels) in Khuzestan region, southwest of Iran to help establish the NDRLs (national diagnostic reference levels). Methods: Patient doses were assessed from patient's anatomical data and exposure parameters based on the IAEA indirect dosimetry method. With regard to this method, exposure parameters such as tube output, kVp, mAs, FFD and patient anatomical data were used for calculating ESD (entrance skin dose) of patients. This study was conducted on 250 standard patients (50% men and 50% women) at eight high-patient-load imaging centers. Results: The results indicate that mean ESDs for the both pelvic and abdomen examinations were lower than the IAEA and EC reference levels, 2.3 and 3.7 mGy, respectively. Mean applied kVps were 67 and 70 and mean FFDs were 103 and 109, respectively. Tube loadings obtained in this study for pelvic examination were lower than all the corresponding values in the reviewed literature. Likewise, the average annual patient load across all hospitals were more than 37000 patients, i.e. more than 100 patients a day. Conclusions: The authors recommend that DRLs (diagnostic reference levels) obtained in this region, which are the first available data, can be used as local DRLs for pelvic and abdomen procedures. This work also provides that on-the-job training programs for staffs and close cross collaboration between physicists and physicians should be strongly considered.

  18. Dose reference levels in Spanish intraoral dental radiology: stabilisation of the incorporation of digital systems in dental clinical practices

    International Nuclear Information System (INIS)

    Alcaraz, M.; Velasco, F.; Olivares, A.; Velasco, E.; Canteras, M.

    2016-01-01

    A total of 34 044 official quality assurance reports in dental radiodiagnostic surgery from 16 regions of Spain, compiled from 2002 to 2014, were studied in order to determine the progress of diagnostic reference levels (DRLs) for obtaining diagnostic images under normal conditions for clinical practice in Spanish dental clinics. A DRL of 2.8 mGy was set in 2014, which represents a 41.7 % decrease compared with that of 2002 (4.8 mGy). Over the same time period, the mean dose fell by 55.2 %. However, over the last 3 y, the stabilisation of the mean dose administered to patients has been observed with only a 6.7 % reduction in DRLs, which corresponds to the stabilisation of dental radiodiagnostic surgery on replacing the use of radiographic film with digital imaging systems. (authors)

  19. Cuban typical doses for 99mTc-DMSA renal gammagraphy studies: a methodology for the establishment of reference levels

    International Nuclear Information System (INIS)

    Diaz Barreto, M.; Varela Corona, C.; Lopez Bejerano, G.M.; Perea Diaz, M.; Paz Viera, J.E.

    2008-01-01

    Since a handful of years ago, international rules on Radiological Protection include the principle of optimization of given dose to patients, if this procedure doesn't lessen diagnosis quality, and the establishment of reference levels of activity. For these reasons, the Radiological Protection staff of Cuban Institute of Nephrology's Nuclear Medicine Service, where morpho functional renal studies are carried out, 70% on infants and young children, started a research on that way. Thus, because their biggest incidence, 99m Tc -DMSA renal gammagraphy studies were chosen, using a General Electric 400 AT Planar Gamma Camera. Studied sample was randomly selected, including adults (12 peoples) and children (23); divided into 4 groups, lessen given dose step by step. Other items were kept in mind in the research, such age, weight, time delayed between administrations and image getting, getting time of each view and total time of the study, as well as radiopharmaceuticals quality and Gamma Camera performance. Image quality was evaluated for each case, using both, objective and subjective criteria. Objective evaluation was done by using contrast/noise ratios and variance of the random noise. They were used to develop clustering and discriminant analysis over the independent variables to detect groups with differentiated image quality from the physical and mathematical point of view. Subjective evaluation was performed using the criteria of two expert observers who had no information about the activity levels used. They evaluated image quality separately, giving a good, regular or bad evaluation for each image. As a conclusion, we found that it is possible to reduce the given activities in 50% and thus, indirectly, to reduce doses for workers and for the public. Additionally, we propose a methodology for the establishment of reference levels for 99m Tc -DMSA renal gammagraphy studies in Cuba, both, for adults and paediatric patients. (author)

  20. Local patient dose diagnostic reference levels in pediatric interventional cardiology in Chile using age bands and patient weight values

    Energy Technology Data Exchange (ETDEWEB)

    Ubeda, Carlos, E-mail: cubeda@uta.cl [Medical Technology Department, Radiological Sciences Center, Health Sciences Faculty, Tarapaca University, Arica 1000000 (Chile); Miranda, Patricia [Hemodynamic Department, Cardiovascular Service, Luis Calvo Mackenna Hospital, Santiago 7500539 (Chile); Vano, Eliseo [Radiology Department, Faculty of Medicine, Complutense University and IdIS, San Carlos Hospital, Madrid 28040 (Spain)

    2015-02-15

    Purpose: To present the results of a patient dose evaluation program in pediatric cardiology and propose local diagnostic reference levels (DRLs) for different types of procedure and age range, in addition to suggesting approaches to correlate patient dose values with patient weight. This study was the first conducted in Latin America for pediatric interventional cardiology under the auspices of the International Atomic Energy Agency. Methods: Over three years, the following data regarding demographic and patient dose values were collected: age, gender, weight, height, number of cine series, total number of cine frames, fluoroscopy time (FT), and two dosimetric quantities, dose-area product (DAP) and cumulative dose (CD), at the patient entrance reference point. The third quartile values for FT, DAP, CD, number of cine series, and the DAP/body weight ratio were proposed as the set of quantities to use as local DRLs. Results: Five hundred and seventeen patients were divided into four age groups. Sample sizes by age group were 120 for <1 yr; 213 for 1 to <5 yr; 82 for 5 to <10 yr; and 102 for 10 to <16 yr. The third quartile values obtained for DAP by diagnostic and therapeutic procedures and age range were 1.17 and 1.11 Gy cm{sup 2} for <1 yr; 1.74 and 1.90 Gy cm{sup 2} for 1 to <5 yr; 2.83 and 3.22 Gy cm{sup 2} for 5 to <10 yr; and 7.34 and 8.68 Gy cm{sup 2} for 10 to <16 yr, respectively. The third quartile value obtained for the DAP/body weight ratio for the full sample of procedures was 0.17 (Gy cm{sup 2}/kg) for diagnostic and therapeutic procedures. Conclusions: The data presented in this paper are an initial attempt at establishing local DRLs in pediatric interventional cardiology, from a large sample of procedures for the standard age bands used in Europe, complemented with the values of the ratio between DAP and patient weight. This permits a rough estimate of DRLs for different patient weights and the refining of these values for the age bands when there

  1. Local patient dose diagnostic reference levels in pediatric interventional cardiology in Chile using age bands and patient weight values

    International Nuclear Information System (INIS)

    Ubeda, Carlos; Miranda, Patricia; Vano, Eliseo

    2015-01-01

    Purpose: To present the results of a patient dose evaluation program in pediatric cardiology and propose local diagnostic reference levels (DRLs) for different types of procedure and age range, in addition to suggesting approaches to correlate patient dose values with patient weight. This study was the first conducted in Latin America for pediatric interventional cardiology under the auspices of the International Atomic Energy Agency. Methods: Over three years, the following data regarding demographic and patient dose values were collected: age, gender, weight, height, number of cine series, total number of cine frames, fluoroscopy time (FT), and two dosimetric quantities, dose-area product (DAP) and cumulative dose (CD), at the patient entrance reference point. The third quartile values for FT, DAP, CD, number of cine series, and the DAP/body weight ratio were proposed as the set of quantities to use as local DRLs. Results: Five hundred and seventeen patients were divided into four age groups. Sample sizes by age group were 120 for <1 yr; 213 for 1 to <5 yr; 82 for 5 to <10 yr; and 102 for 10 to <16 yr. The third quartile values obtained for DAP by diagnostic and therapeutic procedures and age range were 1.17 and 1.11 Gy cm 2 for <1 yr; 1.74 and 1.90 Gy cm 2 for 1 to <5 yr; 2.83 and 3.22 Gy cm 2 for 5 to <10 yr; and 7.34 and 8.68 Gy cm 2 for 10 to <16 yr, respectively. The third quartile value obtained for the DAP/body weight ratio for the full sample of procedures was 0.17 (Gy cm 2 /kg) for diagnostic and therapeutic procedures. Conclusions: The data presented in this paper are an initial attempt at establishing local DRLs in pediatric interventional cardiology, from a large sample of procedures for the standard age bands used in Europe, complemented with the values of the ratio between DAP and patient weight. This permits a rough estimate of DRLs for different patient weights and the refining of these values for the age bands when there may be large differences

  2. Quality assurance in CT: implementation of the updated national diagnostic reference levels using an automated CT dose monitoring system.

    Science.gov (United States)

    Appel, E; Kröpil, P; Bethge, O T; Aissa, J; Thomas, C; Antoch, G; Boos, J

    2018-03-20

    To evaluate the implementation of the updated computed tomography (CT) diagnostic reference levels (DRLs) from the German Federal Office for Radiation Protection into clinical routine using an automatic CT dose monitoring system. CT radiation exposure was analysed before and after implementing the updated national DRLs into routine clinical work in 2016. After the implementation process, institutional CT protocols were mapped to the anatomical regions for which DRLs were provided. Systematically, protocols that exceeded the thresholds were optimised and analysed in detail. The CT radiation output parameters analysed were volumetric CT dose index (CTDIvol) and dose-length product (DLP). Three radiologists evaluated subjective image quality using a three-point Likert scale. The study included 94,258 CT series (from 27,103 CT examinations) in adult patients performed in 2016. When averaged over all body regions with available DRL, institutional CTDIvol/DLP values were always below the DRLs (65.2±32.9%/67.3±41.5% initially; 59.4±32%/60.5±39.9% after optimisation). Values exceeding the national DRLs were found for pelvis (n=268; CTDIvol 107.7±65.7%/DLP 106.3±79.3%), lumbar spine (n=91; 160.8±74.7%/175.2±104.1%), and facial bones (n=527; 108±39%/152.7±75.7%). After optimisation, CTDIvol and DLP were 87.9±73%/87.8±80.8% for the pelvis, 67.8±33.2%/74.5±50.6% for the lumbar spine and 95.1±45.8%/133.3±74.6% for the viscerocranium. An automatic CT dose monitoring system enabled not only comprehensive monitoring of a DRL implementation process but can also help to optimise radiation exposure. Copyright © 2018 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  3. Computed Tomography (CT) radiation dose in children: A survey to propose regional diagnostic reference levels in Greater Accra-Ghana

    International Nuclear Information System (INIS)

    Addo, Patience

    2016-07-01

    The aim of this work was to assess the doses delivered to paediatric patients during computed tomography (CT) examinations of the head, chest and abdomen, and establishing regional diagnostic reference levels (RDRLs) for four age groups. The patient data, technique parameters and dose descriptors collected include: age, sex, tube voltage, tube current, rotation time, slice thickness, scan length, volume CT dose index (CTDI_v_o_l) and dose length product (DLP). Currently, paediatric CT examinations account for 11% of radiation exposure. For the paediatric age groups; < 1 year, (1-5 years), (6-10 years) and (11-15 years), the proposed RDRLs for head in terms of CTDI_v_o_l are (28, 38, 48 and 86 mGy) and in terms of DLP; (395, 487, 601, 1614 mGy cm) respectively. For Chest examinations, proposed RDRLs in terms of CTDI_v_o_l are (1 and 5 mGy) and in terms of DLP; (18 and 110 mGy cm) for age groups; < 1 year and (1-5 years) respectively. For Abdomino-pelvic examinations, proposed RDRLs in terms of CTDI_v_o_l are (3, 3 and 10 mGy) and in terms of DLP; (71, 120 and 494 mGy cm) for age groups; < 1 year, (1-5 years) and (6-10 years) respectively. For abdomen examinations, proposed RDRLs in terms of CTDI_v_o_l are (3, 5 and 5 mGy) and in terms of DLP; (83, 124 and 233 mGy cm) for age groups; < 1 year, (1-5 years) and (11-15 years) respectively. RDRLs have been proposed for CTDI_v_o_l and DLP for head, chest, abdomen and Abdomino-pelvic paediatric CT examinations in this study. An optimisation is required for 11-15 years age group for the DLP values which was higher than their corresponding international DRLs. For an effective optimization of patient protection a trade-off between image quality and patients doses studies should be investigated. (au)

  4. Dose evaluation and establishment of reference levels in activity for nuclear medicine; Avaliação de dose e estabelecimento de níveis de referência em atividade para a medicina nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Julio Cesar de Souza

    2017-07-01

    The International Commission on Radiation Protection (ICRP) has emphasized the importance of accurately determining the mean dose levels, or administered activity, received by the patients for each medical procedure that uses ionizing radiation. However, the number of bibliographic references addressing the need to know and optimize these levels is insufficient, or rather limited, which may lead to non-standardizes techniques, a lack of exposures control, and also the increase of associated radiological risks of these procedures. In this context, a software in Visual Basic® of Microsoft© language was developed whose function is to elaborate a method of obtaining the Reference Levels in Activity (RLA) for nuclear medicine patients by determining the third quartile of the examinations carried out. The program also allows obtaining absorbed dose values in critical organs based on patient specificities as age, sex and Body Mass Index (BMI) in order to evaluate the risk involved in each procedure. The main nuclear medicine diagnostic procedures were evaluated through the database of two public hospitals and a private clinic, obtaining the NRAs of each facility, where the software was validated by comparison with the traditionally accepted calculation methods. Due to the results obtained in each installation, in addition to NRA determination, gaps in treatment capacities and unjustified dose variations for the same procedure were identified, indicating the need for optimization. Thus, the developed program is able to provide the estimated values of effective and absorbed doses involved in each procedure, for each patient, providing reference values for nuclear medicine field, not available in the national scenario so far. (author)

  5. Medical reference dosimetry using EPR measurements of alanine: Development of an improved method for clinical dose levels

    International Nuclear Information System (INIS)

    Helt-Hansen, Jakob; Andersen, Claus Erik; Rosendal, Flemming; Kofoed, Inger Matilde

    2009-01-01

    Electron spin resonance (EPR) is used to determine the absorbed dose of alanine dosimeters exposed to clinical photon beams in a solid-water phantom. Alanine is potentially suitable for medical reference dosimetry, because of its near water equivalence over a wide energy spectrum, low signal fading, non-destructive measurement and small dosimeter size. Material and Methods. A Bruker EMX-micro EPR spectrometer with a rectangular cavity and a measurement time of two minutes per dosimeter was used for reading of irradiated alanine dosimeters. Under these conditions a new algorithm based on scaling of known spectra was developed to extract the alanine signal. Results. The dose accuracy, including calibration uncertainty, is less than 2% (k=1) above 4 Gy (n=4). The measurement uncertainty is fairly constant in absolute terms (∼30 mGy) and the relative uncertainty therefore rises for dose measurements below 4 Gy. Typical reproducibility is <1% (k=1) above 10 Gy and <2% between 4 and 10 Gy. Below 4 Gy the uncertainty is higher. A depth dose curve measurement was performed in a solid-water phantom irradiated to a dose of 20 Gy at the maximum dose point (dmax) in 6 and 18 MV photon beams. The typical difference between the dose measured with alanine in solid water and the dose measured with an ion chamber in a water tank was about 1%. A difference of 2% between 6 and 18 MV was found, possibly due to non-water equivalence of the applied phantom. Discussion. Compared to previously published methods the proposed algorithm can be applied without normalisation of phase shifts caused by changes in the g-value of the cavity. The study shows that alanine dosimetry is a suitable candidate for medical reference dosimetry especially for quality control applications

  6. Guidance levels, achievable doses and expectation levels

    International Nuclear Information System (INIS)

    Li, Lianbo; Meng, Bing

    2002-01-01

    The National Radiological Protection Board (NRPB), the International Atomic Energy Agency (IAEA) and the Commission of the European Communities (CEC) published their guidance levels and reference doses for typical X-ray examination and nuclear medicine in their documents in 1993, 1994 and 1996 respectively. From then on, the concept of guidance levels or reference doses have been applied to different examinations in the field of radiology and proved to be effective for reduction of patient doses. But the guidance levels or reference doses are likely to have some shortcomings and can do little to make further reduction of patient dose in the radiology departments where patient dose are already below them. For this reason, the National Radiological Protection Board (NRPB) proposed a concept named achievable doses which are based on the mean dose observed for a selected sample of radiology departments. This paper will review and discuss the concept of guidance levels and achievable doses, and propose a new concept referred to as Expectation Levels that will encourage the radiology departments where patient dose are already below the guidance levels to keep patient dose as low as reasonably achievable. Some examples of the expectation levels based on the data published by a few countries are also illustrated in this paper

  7. Reference handbook: Level detectors

    International Nuclear Information System (INIS)

    1990-01-01

    The purpose of this handbook is to provide Rocky Flats personnel with the information necessary to understand level measurement and detection. Upon completion of this handbook you should be able to do the following: List three reasons for measuring level. Describe the basic operating principles of the sight glass. Demonstrate proper techniques for reading a sight glass. Describe the basic operating principles of a float level detector. Describe the basic operating principles of a bubbler level indicating system. Explain the differences between a wet and dry reference leg indicating system, and describe how each functions. This handbook is designed for use by experienced Rocky Flats operators to reinforce and improve their current knowledge level, and by entry-level operators to ensure that they possess a minimum level of fundamental knowledge. Level Detectors is applicable to many job classifications and can be used as a reference for classroom work or for self-study. Although this reference handbook is by no means all-encompassing, you will gain enough information about this subject area to assist you in contributing to the safe operation of Rocky Flats Plant

  8. Reference Dose Rates for Fluoroscopy Guided Interventions

    International Nuclear Information System (INIS)

    Geleijns, J.; Broerse, J.J.; Hummel, W.A.; Schalij, M.J.; Schultze Kool, L.J.; Teeuwisse, W.; Zoetelief, J.

    1998-01-01

    The wide diversity of fluoroscopy guided interventions which have become available in recent years has improved patient care. They are being performed in increasing numbers, particularly at departments of cardiology and radiology. Some procedures are very complex and require extended fluoroscopy times, i.e. longer than 30 min, and radiation exposure of patient and medical staff is in some cases rather high. The occurrence of radiation-induced skin injuries on patients has shown that radiation protection for fluoroscopy guided interventions should not only be focused on stochastic effects, i.e. tumour induction and hereditary risks, but also on potential deterministic effects. Reference dose levels are introduced by the Council of the European Communities as an instrument to achieve optimisation of radiation protection in radiology. Reference levels in conventional diagnostic radiology are usually expressed as entrance skin dose or dose-area product. It is not possible to define a standard procedure for complex interventions due to the large inter-patient variations with regard to the complexity of specific interventional procedures. Consequently, it is not realistic to establish a reference skin dose or dose-area product for complex fluoroscopy guided interventions. As an alternative, reference values for fluoroscopy guided interventions can be expressed as the entrance dose rates on a homogeneous phantom and on the image intensifier. A protocol has been developed and applied during a nationwide survey of fluoroscopic dose rate during catheter ablations. From this survey reference entrance dose rates of respectively 30 mGy.min -1 on a polymethylmethacrylate (PMMA) phantom with a thickness of 21 cm, and of 0.8 μGy.s -1 on the image intensifier have been derived. (author)

  9. Methodology for setting the reference levels in the measurements of the dose rate absorbed in air due to the environmental gamma radiation

    International Nuclear Information System (INIS)

    Dominguez Ley, Orlando; Capote Ferrera, Eduardo; Caveda Ramos, Celia; Alonso Abad, Dolores

    2008-01-01

    Full text: The methodology for setting the reference levels of the measurements of the gamma dose rate absorbed in the air is described. The registration level was obtained using statistical methods. To set the alarm levels, it was necessary to begin with certain affectation level, which activates the investigation operation mode when being reached. It is was necessary to transform this affectation level into values of the indicators selected to set the appearance of an alarm in the network, allowing its direct comparison and at the same time a bigger operability of this one. The affectation level was assumed as an effective dose of 1 mSv/y, which is the international dose limit for public. The conversion factor obtained in a practical way as a consequence of the Chernobyl accident was assumed, converting the value of annual effective dose into values of effective dose rate in air. These factors are the most important in our work, since the main task of the National Network of Environmental Radiological Surveillance of the Republic of Cuba is detecting accidents with a situations regional affectation, and this accident is precisely an example of pollution at this scale. The alarm level setting was based on the results obtained in the first year of the Chernobyl accident. For this purpose, some transformations were achieved. In the final results, a correction factor was introduced depending on the year season the measurement was made. It was taken into account the influence of different meteorological events on the measurement of this indicator. (author)

  10. Investigation of reference levels and radiation dose associated with abdominal EVAR (endovascular aneurysm repair) procedures across several European Centres

    Energy Technology Data Exchange (ETDEWEB)

    Tuthill, E.; Rainford, L. [University College Dublin, Diagnostic Imaging, School of Medicine, Dublin (Ireland); O' Hora, L.; O' Donohoe, M. [Mater Misericordiae University Hospital, Dublin (Ireland); Panci, S. [San Giovanni di Dio Hospital, Florence (Italy); Gilligan, P.; Fox, E. [Mater Private Hospital, Dublin (Ireland); Campion, D. [Mauriziano-Umberto Hospital, Turin (Italy); Trenti, R. [Policlinico S. Orsola-Malpighi, Bologna (Italy); Catania, D. [AITRI, Association of Italian Interventional Radiographers, Milan (Italy)

    2017-11-15

    Endovascular aneurysm repair (EVAR) is considered the treatment of choice for abdominal aortic aneurysms with suitable anatomy. In order to improve radiation safety, European Directive (2013/59) requires member states to implement diagnostic reference levels (DRLs) in radio-diagnostic and interventional procedures. This study aimed to determine local DRLs for EVAR across five European centres and identify an interim European DRL, which currently remains unestablished. Retrospective data was collected for 180 standard EVARs performed between January 2014 and July 2015 from five specialist centres in Ireland (n=2) and Italy (n=3). Data capture included: air kerma-area product (P{sub KA}), total air kerma at the reference point (K{sub a,r}), fluoroscopic time (FT), number of acquisitions, frame rate of acquisition, type of acquisition, patient height, weight, and gender. The mean values for each site A, B, C, D, and E were: P{sub KA}s of 4343 ± 994 μGym{sup 2}, 18,200 ± 2141 μGym{sup 2}, 11,423 ± 1390 μGym{sup 2}, 7796 ± 704 μGym{sup 2}, 31,897 ± 5798 μGym{sup 2}; FTs of 816 ± 92 s, 950 ± 150 s, 708 ± 70 s, 972 ± 61 s, 827 ± 118 s; and number of acquisitions of 6.72 ± 0.56, 10.38 ± 1.54, 4.74 ± 0.19, 5.64 ± 0.36, 7.28 ± 0.65, respectively. The overall pooled 75th percentile P{sub KA} was 15,849 μGym{sup 2}. Local reference levels were identified. The pooled data has been used to establish an interim European DRL for EVAR procedures. (orig.)

  11. ENRAF gauge reference level calculations

    Energy Technology Data Exchange (ETDEWEB)

    Huber, J.H., Fluor Daniel Hanford

    1997-02-06

    This document describes the method for calculating reference levels for Enraf Series 854 Level Detectors as installed in the tank farms. The reference level calculation for each installed level gauge is contained herein.

  12. Dose limits, constraints, reference levels. What does it mean for radiation protection?; Grenzwerte, Richtwerte, Referenzwerte. Was bedeutet das fuer den Strahlenschutz

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-07-01

    The established concept of radiation protection with its basic principles justification, optimization, and limitation has proved its value and is going to be continued. In its deeper meaning, however, the concept is rather subtle and complex. Furthermore, in some aspects there remain some breaches or inconsistencies. This is just true for the terms dose limit, reference lever, and constraint that are tightly associated with the radiation protection principles. In order to guarantee the ability of radiation protection in whole extent, the subtle differences of meaning have to be communicated. There is a permanent need to defend the conceptual function of these terms against deliberate or undeliberate misinterpretations. Reference levels are definitely not the same as dose limits and they may not be misused as such. Any attempt to misinterpret fundamental radiation protection principles for selfish purposes should discouraged vigorously.

  13. Insignificant levels of dose

    International Nuclear Information System (INIS)

    Webb, G.A.M.; McLean, A.S.

    1977-01-01

    The procedures recommended by the International Commission on Radiological Protection (ICRP) for making decisions concerning controllable sources of radiation exposure of the public include 'justification' and 'optimisation'. The tool recommended by the ICRP for reaching these decisions is collective dose or dose commitment supplemented by consideration of doses to individuals. In both these considerations the practical problem arises of whether very small doses to large numbers of people should contribute to the final decision-making process. It may be that at levels of dose which are small increments on natural background, the relationship between dose and effect is linear even though the slope may be close to zero. If so, collective dose is a meaningful concept and the calculation of total detriment for the purpose of justification could legitimately include all doses. In the calculation of collective doses for the purpose of optimisation, which involves decisions on how much money or resource should be allocated to dose reduction, it is necessary to appraise radiation detriment realistically. At low levels of dose to the individual such as those small by comparison with variations in natural background within the UK, the risk to the individual is such that his well-being will not be significantly changed by the presence or absence of the radiation dose. These small doses, which are well below the point at which an individual attaches significance, should not carry a societal significance. Societal acceptance of risk is analysed with a view to assessing a level of possible risk, and hence dose, below which resources should not in general be diverted to secure further reduction. A formulation for collective dose commitment is proposed incorporating a cut-off to exclude insignificant doses. The implications of this formulation in practical situations are discussed

  14. Cloud-based CT dose monitoring using the DICOM-structured report. Fully automated analysis in regard to national diagnostic reference levels

    International Nuclear Information System (INIS)

    Boos, J.; Rubbert, C.; Heusch, P.; Lanzman, R.S.; Aissa, J.; Antoch, G.; Kroepil, P.

    2016-01-01

    To implement automated CT dose data monitoring using the DICOM-Structured Report (DICOM-SR) in order to monitor dose-related CT data in regard to national diagnostic reference levels (DRLs). Materials and Methods: We used a novel in-house co-developed software tool based on the DICOM-SR to automatically monitor dose-related data from CT examinations. The DICOM-SR for each CT examination performed between 09/2011 and 03/2015 was automatically anonymized and sent from the CT scanners to a cloud server. Data was automatically analyzed in accordance with body region, patient age and corresponding DRL for volumetric computed tomography dose index (CTDI vol ) and dose length product (DLP). Results: Data of 36 523 examinations (131 527 scan series) performed on three different CT scanners and one PET/CT were analyzed. The overall mean CTDI vol and DLP were 51.3 % and 52.8 % of the national DRLs, respectively. CTDI vol and DLP reached 43.8 % and 43.1 % for abdominal CT (n = 10 590), 66.6 % and 69.6 % for cranial CT (n = 16 098) and 37.8 % and 44.0 % for chest CT (n = 10 387) of the compared national DRLs, respectively. Overall, the CTDI vol exceeded national DRLs in 1.9 % of the examinations, while the DLP exceeded national DRLs in 2.9 % of the examinations. Between different CT protocols of the same body region, radiation exposure varied up to 50 % of the DRLs. Conclusion: The implemented cloud-based CT dose monitoring based on the DICOM-SR enables automated benchmarking in regard to national DRLs. Overall the local dose exposure from CT reached approximately 50 % of these DRLs indicating that DRL actualization as well as protocol-specific DRLs are desirable. The cloud-based approach enables multi-center dose monitoring and offers great potential to further optimize radiation exposure in radiological departments.

  15. National reference doses for dental cephalometric radiography.

    Science.gov (United States)

    Holroyd, J R

    2011-12-01

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

  16. Local diagnostic reference level based on size-specific dose estimates: Assessment of pediatric abdominal/pelvic computed tomography at a Japanese national children's hospital

    Energy Technology Data Exchange (ETDEWEB)

    Imai, Rumi; Miyazaki, Osamu; Kurosawa, Hideo; Nosaka, Shunsuke [National Center for Child Health and Development, Department of Radiology, Setagaya-ku, Tokyo (Japan); Horiuchi, Tetsuya [Osaka University, Department of Medical Physics and Engineering, Division of Medical Technology and Science, Course of Health Science, Graduate School of Medicine, Suita, Osaka (Japan)

    2015-03-01

    A child's body size is not accurately reflected by volume CT dose index (CTDI{sub vol}) and dose-length product (DLP). Size-specific dose estimation (SSDE) was introduced recently as a new index of radiation dose. However, it has not yet been established as a diagnostic reference level (DRL). To calculate the SSDE of abdominal/pelvic CT and compare the SSDE with CTDI{sub vol}. To calculate the DRLs of CTDI{sub vol} and SSDE. Our hypotheses are: SSDE values will be greater than CTDI{sub vol}, and our DRL will be smaller than the known DRLs of other countries. The CTDI{sub vol} and DLP of 117 children who underwent abdominal/pelvic CT were collected retrospectively. The SSDE was calculated from the sum of the lateral and anteroposterior diameters. The relationships between body weight and effective diameter and between effective diameter and CTDI{sub vol}/SSDE were compared. Further, the local DRL was compared with the DRLs of other countries. Body weight and effective diameter and effective diameter and SSDE were positively correlated. In children ages 1, 5 and 10 years, the SSDE is closer to the exposure dose of CTDI{sub vol} for the 16-cm phantom, while in children ages 15 years, the SSDE falls between CTDI{sub vol} for the 16-cm phantom and that for the 32-cm phantom. The local DRL was lower than those of other countries. With SSDE, the radiation dose increased with increasing body weight. Since SSDE takes body size into account, it proved to be a useful indicator for estimating the exposure dose. (orig.)

  17. A comparison of mean glandular dose diagnostic reference levels within the all-digital irish national breast screening programme and the Irish symptomatic breast services

    International Nuclear Information System (INIS)

    O'Leary, D.; Rainford, L.

    2013-01-01

    Data on image quality, compression and radiation dose were collected from symptomatic breast units within the Republic of Ireland. Quantitative and qualitative data were analysed using SPSS. Recommendations of mean glandular dose (MGD) diagnostic reference levels were made at various levels for film-screen and full field digital mammography units to match levels published worldwide. MGDs received by symptomatic breast patients within Ireland are higher than those received in the all-digital Irish Breast Screening service; 55-65 mm breast: 1.75 mGy (screening) vs. 2.4 mGy (symptomatic) at the 95. percentile; various reasons are proposed for the differences. MGDs achieved in the screening service may be lower because of the exacting requirements for radiographer training, characteristics of the patients and equipment quality assurance levels. More precise imaging guidelines, standards and training of symptomatic radiographers performing mammography are suggested to remediate MGDs delivered to the breasts of Irish women attending the symptomatic breast services. (authors)

  18. Patient Dose During Carotid Artery Stenting With Embolic-Protection Devices: Evaluation With Radiochromic Films and Related Diagnostic Reference Levels According to Factors Influencing the Procedure

    International Nuclear Information System (INIS)

    D’Ercole, Loredana; Quaretti, Pietro; Cionfoli, Nicola; Klersy, Catherine; Bocchiola, Milena; Rodolico, Giuseppe; Azzaretti, Andrea; Lisciandro, Francesco; Cascella, Tommaso; Zappoli Thyrion, Federico

    2013-01-01

    To measure the maximum entrance skin dose (MESD) on patients undergoing carotid artery stenting (CAS) using embolic-protection devices, to analyze the dependence of dose and exposure parameters on anatomical, clinical, and technical factors affecting the procedure complexity, to obtain some local diagnostic reference levels (DRLs), and to evaluate whether overcoming DRLs is related to procedure complexity. MESD were evaluated with radiochromic films in 31 patients (mean age 72 ± 7 years). Five of 33 (15 %) procedures used proximal EPD, and 28 of 33 (85 %) procedures used distal EPD. Local DRLs were derived from the recorded exposure parameters in 93 patients (65 men and 28 women, mean age 73 ± 9 years) undergoing 96 CAS with proximal (33 %) or distal (67 %) EPD. Four bilateral lesions were included. MESD values (mean 0.96 ± 0.42 Gy) were FR ) were 269 Gy cm 2 , 28 minutes, and 251, respectively. Only simultaneous bilateral treatment was associated with KAP (odds ratio [OR] 10.14, 95 % confidence interval [CI] 1–102.7, p FR overexposures (OR 10.8, 95 % CI 1.1–109.5, p FR overexposure (OR 2.8, 95 % CI 1.1–7.4, p = 0.040). At multivariable analysis, stenosis ≥ 90 % (OR 2.8, 95 % CI 1.1–7.4, p = 0.040) and bilateral treatment (OR 10.8, 95 % CI 1.1–109.5, p = 0.027) were associated with overexposure for two or more parameters. Skin doses are not problematic in CAS with EPD because these procedures rarely lead to doses >2 Gy.

  19. Fast in vivo volume dose reconstruction via reference dose perturbation

    International Nuclear Information System (INIS)

    Lu, Weiguo; Chen, Mingli; Mo, Xiaohu; Parnell, Donald; Olivera, Gustavo; Galmarini, Daniel

    2014-01-01

    Purpose: Accurate on-line reconstruction of in-vivo volume dose that accounts for both machine and patient discrepancy is not clinically available. We present a simple reference-dose-perturbation algorithm that reconstructs in-vivo volume dose fast and accurately. Methods: We modelled the volume dose as a function of the fluence map and density image. Machine (output variation, jaw/leaf position errors, etc.) and patient (setup error, weight loss, etc.) discrepancies between the plan and delivery were modelled as perturbation of the fluence map and density image, respectively. Delivered dose is modelled as perturbation of the reference dose due to change of the fluence map and density image. We used both simulated and clinical data to validate the algorithm. The planned dose was used as the reference. The reconstruction was perturbed from the reference and accounted for output-variations and the registered daily image. The reconstruction was compared with the ground truth via isodose lines and the Gamma Index. Results: For various plans and geometries, the volume doses were reconstructed in few seconds. The reconstruction generally matched well with the ground truth. For the 3%/3mm criteria, the Gamma pass rates were 98% for simulations and 95% for clinical data. The differences mainly appeared on the surface of the phantom/patient. Conclusions: A novel reference-dose-perturbation dose reconstruction model is presented. The model accounts for machine and patient discrepancy from planning. The algorithm is simple, fast, yet accurate, which makes online in-vivo 3D dose reconstruction clinically feasible.

  20. Establishing diagnostic reference levels in digital radiology

    International Nuclear Information System (INIS)

    Bana, Remy Wilson

    2016-04-01

    Medical application of radiation has gained wider study since diagnostic radiology plays a very important role in modern medicine. The need of the service seems to increase since the invention of digital radiology as a new technology that promises greater accuracy while minimizing patient dose. However, it is not exempted in the harmonization of doses delivered to the patient undergoing same radiologic examination in different institutions either regional or nationwide. The objective of this project was to review the establishment of Diagnostic Reference Levels (DRLs) in digital radiology at National level with the aim to reduce patient dose while maintaining appropriate image quality. A general discussion on digital radiology has been presented focusing on the optimization of patient dose as well as dosimetric quantities used for the establishment of DRLs. Recommendations have been provided for Rwanda to initiate steps to establish National Diagnostic Reference Levels for common procedures in digital radiology. (au)

  1. Patient Dose During Carotid Artery Stenting With Embolic-Protection Devices: Evaluation With Radiochromic Films and Related Diagnostic Reference Levels According to Factors Influencing the Procedure

    Energy Technology Data Exchange (ETDEWEB)

    D' Ercole, Loredana, E-mail: l.dercole@smatteo.pv.it [Fondazione IRCCS Policlinico San Matteo, Department of Medical Physics (Italy); Quaretti, Pietro; Cionfoli, Nicola [Fondazione IRCCS Policlinico San Matteo, Department of Radiology (Italy); Klersy, Catherine [Fondazione IRCCS Policlinico San Matteo, Biometry and Clinical Epidemiology Service, Research Department, (Italy); Bocchiola, Milena [Fondazione IRCCS Policlinico San Matteo, Department of Medical Physics (Italy); Rodolico, Giuseppe; Azzaretti, Andrea [Fondazione IRCCS Policlinico San Matteo, Department of Radiology (Italy); Lisciandro, Francesco [Fondazione IRCCS Policlinico San Matteo, Department of Medical Physics (Italy); Cascella, Tommaso; Zappoli Thyrion, Federico [Fondazione IRCCS Policlinico San Matteo, Department of Radiology (Italy)

    2013-04-15

    To measure the maximum entrance skin dose (MESD) on patients undergoing carotid artery stenting (CAS) using embolic-protection devices, to analyze the dependence of dose and exposure parameters on anatomical, clinical, and technical factors affecting the procedure complexity, to obtain some local diagnostic reference levels (DRLs), and to evaluate whether overcoming DRLs is related to procedure complexity. MESD were evaluated with radiochromic films in 31 patients (mean age 72 {+-} 7 years). Five of 33 (15 %) procedures used proximal EPD, and 28 of 33 (85 %) procedures used distal EPD. Local DRLs were derived from the recorded exposure parameters in 93 patients (65 men and 28 women, mean age 73 {+-} 9 years) undergoing 96 CAS with proximal (33 %) or distal (67 %) EPD. Four bilateral lesions were included. MESD values (mean 0.96 {+-} 0.42 Gy) were <2 Gy without relevant dependence on procedure complexity. Local DRL values for kerma area product (KAP), fluoroscopy time (FT), and number of frames (N{sub FR}) were 269 Gy cm{sup 2}, 28 minutes, and 251, respectively. Only simultaneous bilateral treatment was associated with KAP (odds ratio [OR] 10.14, 95 % confidence interval [CI] 1-102.7, p < 0.05) and N{sub FR} overexposures (OR 10.8, 95 % CI 1.1-109.5, p < 0.05). Type I aortic arch decreased the risk of FT overexposure (OR 0.4, 95 % CI 0.1-0.9, p = 0.042), and stenosis {>=} 90 % increased the risk of N{sub FR} overexposure (OR 2.8, 95 % CI 1.1-7.4, p = 0.040). At multivariable analysis, stenosis {>=} 90 % (OR 2.8, 95 % CI 1.1-7.4, p = 0.040) and bilateral treatment (OR 10.8, 95 % CI 1.1-109.5, p = 0.027) were associated with overexposure for two or more parameters. Skin doses are not problematic in CAS with EPD because these procedures rarely lead to doses >2 Gy.

  2. Establishing Local Reference Dose Values and Optimisation Strategies

    International Nuclear Information System (INIS)

    Connolly, P.; Moores, B.M.

    2000-01-01

    The revised EC Patient Directive 97/43 EURATOM introduces the concepts of clinical audit, diagnostic reference levels and optimisation of radiation protection in diagnostic radiology. The application of reference dose levels in practice involves the establishment of reference dose values as actual measurable operational quantities. These values should then form part of an ongoing optimisation and audit programme against which routine performance can be compared. The CEC Quality Criteria for Radiographic Images provides guidance reference dose values against which local performance can be compared. In many cases these values can be improved upon quite considerably. This paper presents the results of a local initiative in the North West of the UK aimed at establishing local reference dose values for a number of major hospital sites. The purpose of this initiative is to establish a foundation for both optimisation strategies and clinical audit as an ongoing and routine practice. The paper presents results from an ongoing trial involving patient dose measurements for several radiological examinations upon the sites. The results of an attempt to establish local reference dose values from measured dose values and to employ them in optimisation strategies are presented. In particular emphasis is placed on the routine quality control programmes necessary to underpin this strategy including the effective data management of results from such programmes and how they can be employed to optimisation practices. (author)

  3. Diagnostic reference levels in medical imaging

    International Nuclear Information System (INIS)

    Rosenstein, M.

    2001-01-01

    The paper proposes additional advice to national or local authorities and the clinical community on the application of diagnostic reference levels as a practical tool to manage radiation doses to patients in diagnostic radiology and nuclear medicine. A survey was made of the various approaches that have been taken by authoritative bodies to establish diagnostic reference levels for medical imaging tasks. There are a variety of ways to implement the idea of diagnostic reference levels, depending on the medical imaging task of interest, the national or local state of practice and the national or local preferences for technical implementation. The existing International Commission on Radiological Protection (ICRP) guidance is reviewed, the survey information is summarized, a set of unifying principles is espoused and a statement of additional advice that has been proposed to ICRP Committee 3 is presented. The proposed advice would meet a need for a unifying set of principles to provide a framework for diagnostic reference levels but would allow flexibility in their selection and use. While some illustrative examples are given, the proposed advice does not specify the specific quantities to be used, the numerical values to be set for the quantities or the technical details of how national or local authorities should implement diagnostic reference levels. (author)

  4. Swiss National Reference Levels in Fluoroscopy

    International Nuclear Information System (INIS)

    Aroua, A.; Baechler, S.; Verdun, F.R.; Rickli, H.; Trueb, Ph.R.; Vock, P.

    2006-01-01

    A nationwide survey was launched in Switzerland in order to investigate the use of fluoroscopy and to establish national reference levels (R.L.) for dose-intensive procedures particularly in interventional radiology. The 2-year investigation covered 5 radiology and 9 cardiology departments in public hospitals and private clinics, and focused on twelve types of examinations: six diagnostic and six interventional. The performance of the fluoroscopy units used in these health-care centres (image quality and dose) was assessed extensively and 1000 examinations were registered. Information on the fluoroscopy time (T), the number of frames (N), the dose-area product (D.A.P.), the difficulty of the case, the age, gender, height and weight of the patient, as well as the experience of the practitioner was provided. The whole set of data was used in relative values (to the mean values for each type of examination) to establish the distributions of T, N and the D.A.P.. From these distributions a set of R.L. values was deduced for the types of examinations investigated using the 3.-quartile method. The R.L. values found are compared to the data published in the literature. (authors)

  5. Method of evaluation of diagnostics reference levels in computerized tomography

    International Nuclear Information System (INIS)

    Vega, Walter Flores

    1999-04-01

    Computerized tomography is a complex technique with several selectable exposition parameters delivering high doses to the patient. In this work it was developed a simple methodology to evaluate diagnostic reference levels in computerized tomography, using the concept of Multiple Scan Average Dose (MSAD), recently adopted by the Health Ministry. For evaluation of the MSAD, a dose distribution was obtained through a measured dose profile on the axial axis of a water phantom with thermoluminescence dosemeters, TLD-100, for different exam technique. The MSAD was evaluated hrough two distinct methods. First, it was evaluated by the integration of the dose profile of a single slice and, second, obtained by the integration on central slice of the profile of several slices. The latter is in of accordance with the ionization chamber method, suggesting to be the most practical method of dose evaluation to be applied in the diagnostic reference level assessment routine for CT, using TLDs. (author)

  6. Introduction of guidance dose levels inpaediatrics CT

    International Nuclear Information System (INIS)

    Verdun, F.R.; Valley, J.F.; Bernasconi, M.; Schnyder, P.; Gudinchet, F.

    2001-01-01

    The purpose of this work is to present a methodology in order to define reference levels for chest or abdominal CT examinations performed on children. For children aged from 0 to 6 the CTDI w measured in the head test object (i.e. diameter 16 cm) should be used as a dose indicator. For children older than 12 years old the CTDI w measured in the body test object (i.e. 32 cm) should be used as a dose indicator. For children aged between 6 to 12 we propose to use an intermediate CTDI w in order to avoid an over or underestimation of the dose delivered in the slices. Finally a set of dose length products (DLP) measured in our centre for standard abdominal acquisitions will be given. (author)

  7. Determination of dose to patient in different teams of TC and assessment with international reference levels; Determinacion de dosis a pacientes en diferentes equipos de TC y evaluacion con niveles de referencia internacionales

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz Morales, C.; Fernandez lara, A. A.; Buades Forner, M. J.; Tobarra Gonzalez, B. M.

    2013-07-01

    The increase in CT studies and the differences observed between the different equipment used in our hospital prompted us to determine the doses to patients in different studies and check the results obtained with the reference values published internationally. (Author)

  8. 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)

  9. Reference levels for assays in opened installations of industrial radiography

    International Nuclear Information System (INIS)

    Leocadio, Joao C.; Tauhata, Luiz; Crispim, Verginia R.

    2001-01-01

    This work had as objectives to analyze the facilities open of industrial x-ray to obtain the distribution of doses in the operators and present proposed for the reference levels. The results of the monitoring revealed an improvement of the radiation protection conditions in the facilities and that the risk of potential exposure was reduced. The advantage of the proposed reference levels is that the supervisors would enlarge the frequency of audits in the facilities opened to accomplish the investigations and interventions.The facilities open with 'bunkers' presented distributions with 95% of the doses below 0,2 mSv and the distributions of the facilities with cordoned area they had 75% of the doses below 0,4 mSv. (author)

  10. Patient dose reference values for explorations of radiodiagnostic

    International Nuclear Information System (INIS)

    Vano, E.; Gonzalez, L.; Moran, P.; Calzado, A.; Delgado, V.; Ruiz, M.J.

    1992-01-01

    Among the results of the research programs developed in the European Community dealing with radiological protection, dose estimation and quality control in radiodiagnostics, the preparation of a document on Quality criteria for radiodiagnostic images is worthy of note. This document proposes criteria for image quality and patient dose reference values for explorations of thorax, cranium, lumbar region, pelvis, urinary tract and breast. Said reference values, while indicative, are merely an average approximation, from which the radiodiagnostic services of each area may differ significantly, as can be deduced from a EC-coordinated project. With this in mind, and following a strategy applied in the EC to establish said reference values, in this report, provisional reference values, specific for Spain, are proposed for simple examinations (those analyzed by the group of EC experts, among others) and complex probes (intravenous urography, opaque enema and esophagogastroduodenal enema). (author)

  11. Practical considerations in the development and application of reference levels

    International Nuclear Information System (INIS)

    Selby, J. M.; Kennedy, W. E. Jr.; Swinth, K. L.; Gilbert, R. O.; Soldat, J. K.

    1988-05-01

    Radiological exposures to the public during an accident that releases radioactive materials to the environment occur initially through the air pathway, secondly through a water pathway, and finally, through the food chain. From these exposure pathways, reference levels of radionuclides must be applied to limit public radiation doses. Such reference levels are difficult to develop and apply, particularly if the contaminants are transuranic elements such as plutonium. The reference level must be related to a resultant theoretical dose to the public through generic calculations. However, to permit rapid decisions after an accident, the reference levels need to be related to conditions or media in the environment that can be directly measured. They must also be tied to specific countermeasures such as sheltering, evacuation, or interdiction of drinking water or food supplies. This paper discusses the practical considerations in the development and application of reference levels for transuranic in the environment and the present capability to rapidly detect and quantify their concentrations following accidental contamination events. 16 refs., 3 tabs

  12. Reference doses and patient size in paediatric radiology

    International Nuclear Information System (INIS)

    Hart, D.; Wall, B.; Shrimpton, P.

    2000-01-01

    There is a wide range in patient size from a newborn baby to a 15 year old adolescent. Reference doses for paediatric radiology can sensibly be established only for specific sizes of children. Here five standard sizes have been chosen, representing 0 (newborn), 1, 5, 10 and 15 year old patients. This selection of standard ages has the advantage of matching the paediatric mathematical phantoms which are often used in Monte Carlo organ dose calculations. A method has been developed for calculating factors for normalising doses measured on individual children to those for the nearest standard-sized 'child'. These normalisation factors for entrance surface dose (ESD) and dose-area product (DAP) measurements depend on the thickness of the real child, the thickness of the nearest standard 'child', and an effective linear attenuation coefficient (μ) which is itself a function of the x-ray spectrum, the field size, and whether or not an antiscatter grid is used. Entrance and exit dose measurements were made with phantom material representing soft tissue to establish μ values for abdominal and head examinations, and with phantom material representing lung for chest examinations. These measurements of μ were confirmed and extended to other x-ray spectra and field sizes by Monte Carlo calculations. The normalisation factors are tabulated for ESD measurements for specific radiographic projections through the head and trunk, and for DAP measurements for complete multiprojection examinations in the trunk. The normalisation factors were applied to European survey data for entrance surface dose and dose-area product measurements to derive provisional reference doses for common radiographic projections and for micturating cystourethrography (MCU) examinations - the most frequent fluoroscopic examination on children. (author)

  13. Application of the hybrid approach to the benchmark dose of urinary cadmium as the reference level for renal effects in cadmium polluted and non-polluted areas in Japan

    International Nuclear Information System (INIS)

    Suwazono, Yasushi; Nogawa, Kazuhiro; Uetani, Mirei; Nakada, Satoru; Kido, Teruhiko; Nakagawa, Hideaki

    2011-01-01

    Objectives: The aim of this study was to evaluate the reference level of urinary cadmium (Cd) that caused renal effects. An updated hybrid approach was used to estimate the benchmark doses (BMDs) and their 95% lower confidence limits (BMDL) in subjects with a wide range of exposure to Cd. Methods: The total number of subjects was 1509 (650 men and 859 women) in non-polluted areas and 3103 (1397 men and 1706 women) in the environmentally exposed Kakehashi river basin. We measured urinary cadmium (U-Cd) as a marker of long-term exposure, and β2-microglobulin (β2-MG) as a marker of renal effects. The BMD and BMDL that corresponded to an additional risk (BMR) of 5% were calculated with background risk at zero exposure set at 5%. Results: The U-Cd BMDL for β2-MG was 3.5 μg/g creatinine in men and 3.7 μg/g creatinine in women. Conclusions: The BMDL values for a wide range of U-Cd were generally within the range of values measured in non-polluted areas in Japan. This indicated that the hybrid approach is a robust method for different ranges of cadmium exposure. The present results may contribute further to recent discussions on health risk assessment of Cd exposure.

  14. Application of the hybrid approach to the benchmark dose of urinary cadmium as the reference level for renal effects in cadmium polluted and non-polluted areas in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Suwazono, Yasushi, E-mail: suwa@faculty.chiba-u.jp [Department of Occupational and Environmental Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuoku, Chiba 260-8670 (Japan); Nogawa, Kazuhiro; Uetani, Mirei [Department of Occupational and Environmental Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuoku, Chiba 260-8670 (Japan); Nakada, Satoru [Safety and Health Organization, Chiba University, 1-33 Yayoicho, Inageku, Chiba 263-8522 (Japan); Kido, Teruhiko [Department of Community Health Nursing, Kanazawa University School of Health Sciences, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942 (Japan); Nakagawa, Hideaki [Department of Epidemiology and Public Health, Kanazawa Medical University, 1-1 Daigaku, Uchnada, Ishikawa 920-0293 (Japan)

    2011-02-15

    Objectives: The aim of this study was to evaluate the reference level of urinary cadmium (Cd) that caused renal effects. An updated hybrid approach was used to estimate the benchmark doses (BMDs) and their 95% lower confidence limits (BMDL) in subjects with a wide range of exposure to Cd. Methods: The total number of subjects was 1509 (650 men and 859 women) in non-polluted areas and 3103 (1397 men and 1706 women) in the environmentally exposed Kakehashi river basin. We measured urinary cadmium (U-Cd) as a marker of long-term exposure, and {beta}2-microglobulin ({beta}2-MG) as a marker of renal effects. The BMD and BMDL that corresponded to an additional risk (BMR) of 5% were calculated with background risk at zero exposure set at 5%. Results: The U-Cd BMDL for {beta}2-MG was 3.5 {mu}g/g creatinine in men and 3.7 {mu}g/g creatinine in women. Conclusions: The BMDL values for a wide range of U-Cd were generally within the range of values measured in non-polluted areas in Japan. This indicated that the hybrid approach is a robust method for different ranges of cadmium exposure. The present results may contribute further to recent discussions on health risk assessment of Cd exposure.

  15. The US EPA reference dose for methylmercury: sources of uncertainty

    International Nuclear Information System (INIS)

    Rice, D.C.

    2004-01-01

    The US Environmental Protection Agency (EPA) derived a reference dose for methylmercury in 2001, based on an extensive analysis by the National Research Council (NRC) of the National Academy of Sciences. The NRC performed benchmark dose analysis on a number of endpoints from three longitudinal prospective studies: the Seychelles Islands, the Faroe Islands, and the New Zealand studies. Adverse effects were reported in the latter two studies, but not in the Seychelles study. The NRC also performed an integrative analysis of all three studies. Dose conversion from cord blood or maternal hair mercury concentration was performed by EPA using a one-compartment pharmacokinetic model. A total uncertainty factor of 10 was applied for intrahuman pharmacokinetic and pharmacodynamic variability. There are numerous decisions made by the NRC/EPA that could greatly affect the value of the reference dose (RfD). Some of these include the choice of a linear model for the relationship between mercury body burden and neuropsychological performance, the choice of values of P 0 and the benchmark response, the use of the 'critical study/critical endpoint' approach in the interpretation of the maternal body burden that corresponds to the RfD, the use of central tendencies in a one-compartment pharmacokinetic model rather than the inclusion of the distributions of variables for the population of reproductive-age women, the assumption of unity for the ratio of fetal cord blood to maternal blood methylmercury concentrations, the choice of a total of 10 as an uncertainty factor, and the lack of dose-response analysis for other health effects such as cardiovascular disease. In addition, it may be argued that derivation of a RfD for methylmercury is inappropriate, given that there does not appear to be a threshold for adverse neuropsychological effects based on available data

  16. Guidance document for setting an Acute Reference Dose in Dutch national pesticide evaluations

    NARCIS (Netherlands)

    Raaij MTM van; CSR

    2001-01-01

    This report describes a proposal for the procedures for setting an Acute Reference Dose (ARfD) for pesticides evaluated in the Netherlands. This deals with both evaluations on the national level (on behalf of the Dutch Board for the Authorisation of Pesticides (CTB)) and evaluations at the European

  17. A reference dosimetric system for dose interval of radiotherapy based on alanine/RPE

    International Nuclear Information System (INIS)

    Rodrigues Junior, Orlando; Galante, Ocimar L.; Campos, Leticia L.

    2001-01-01

    This work describes the development of a reference dosimetric system based on alanine/EPR for radiotherapy dose levels. Currently the IPEN is concluding a similar system for the dose range used for irradiation of products, 10-10 5 Gy. The objective of this work is to present the efforts towards to improve the measure accuracy for doses in the range between 1-10 Gy. This system could be used as reference by radiotherapy services, as much in the quality control of the equipment, as for routine accompaniment of more complex handling where the total doses can reach some grays. The system uses alanine as detector and electronic paramagnetic resonance - EPR as measure technique. To reach accuracy better than 5% mathematical studies on the best optimization of the EPR spectrometer parameters and methods for the handling of the EPR sign are discussed. (author)

  18. Reference levels in PTCA as a function of procedure complexity

    International Nuclear Information System (INIS)

    Peterzol, A.; Quai, E.; Padovani, R.; Bernardi, G.; Kotre, C. J.; Dowling, A.

    2005-01-01

    The multicentre assessment of a procedure complexity index (CI) for the introduction of reference levels (RLs) in percutaneous transluminal coronary angio-plasties (PTCA) is presented here. PTCAs were investigated based on methodology proposed by Bernardi et al. Multiple linear stepwise regression analysis, including clinical, anatomical and technical factors, was performed to obtain fluoroscopy time predictors. Based on these regression coefficients, a scoring system was defined and CI obtained. CI was used to classify dose values into three groups: low, medium and high complexity procedures, since there was good correlation (r = 0.41; P 2 , and 12, 20 and 27 min for fluoroscopy time, for the three CI groups. (authors)

  19. Evolution of diagnostic reference levels in Spanish intraoral radiology

    International Nuclear Information System (INIS)

    Alcaraz, M.; Velasco, F.; Martinez-Beneyto, Y.; Alcaraz-Saura, M.; Velasco, E.; Achel, G. D.; Canteras, M.

    2008-01-01

    A total of 16 175 official reports of quality assurance on dental radiodiagnostic surgeries from 16 Spanish autonomous regions compiled during 2002-09 were studied to determine the evolution of diagnostic reference levels (DRLs) for obtaining a diagnostic image in the normal conditions of clinical practice in Spanish dental clinics. A DRL of 3.1 mGy was set in 2009, which represents a 35.4 % decrease compared with the dose determined in 2002 (4.8 mGy). During the same period, the mean dose fell by only 17.2 %. The DRL recommended by the European Union in 2004 for intraoral radiology is 4 mGy, and this study shows that 83.4 % of the installations used a dose below this. Of the installations using indirect or direct digital systems 1.1 and 1.2 %, respectively, used doses higher than those recommended, while 14.2 % of those using radiographic film exceeded this limit. (authors)

  20. Diagnostic Reference Levels in the 1990 and 1996 Recommendations of the ICRP (invited paper)

    International Nuclear Information System (INIS)

    Drexler, G.

    1998-01-01

    A review of and some comments on the paragraphs in the ICRP Publications 60 and 73 are presented, which are relevant to diagnostic reference doses. The content of the statements is traced back by approximately 50 years when ICRP's preoccupation with the future health and well-being of the population is reflected in guidance for characterisation of 'normal operational conditions'. The early ICRP levels of reference doses are compared with the values currently discussed to demonstrate the importance of diagnostic reference doses in the process of optimisation and to show the importance of a continuous review and update of these levels. (author)

  1. Reference levels at diagnosis (NRD) for explorations in TC of the university Hospital Donostia

    International Nuclear Information System (INIS)

    Iriondo Igerabide, U.; Puertolas Hernandez, J. R.; Masso Odriozola, A.; Alonso Espinaco, M. t.; Pino Leon, C.; Lozano Flores, F. J.; Larretxea Etxarri, R.

    2013-01-01

    The objective of this work is the establishment of diagnostic reference levels in TC, for the anatomical regions, in the University Hospital Donostia, in order to reduce the dose to patients and without prejudice to the required diagnosis. (Author)

  2. Comparison between dose values specified at the ICRU reference point and the mean dose to the planning target volume

    International Nuclear Information System (INIS)

    Kukoowicz, Pawel F.; Mijnheer, Bernard J.

    1997-01-01

    Background and purpose: To compare dose values specified at the reference point, as recommended by the International Commission on Radiation Units and Measurements, ICRU, and the mean dose to the planning target volume, PTV. Material and methods: CT-based dose calculations were performed with a 3-D treatment planning system for 6 series of patients treated for bladder, brain, breast, lung, oropharynx and parotid gland tumour. All patients were arbitrarily chosen from a set of previously treated patients irradiated with a two- or three-field technique using customised blocks. Appropriate wedge angles and beam weights were chosen to make the dose distribution as homogeneous as possible. Results: The dose at the ICRU reference point was generally higher than the mean dose to the PTV. The difference between the ICRU reference dose and the mean dose to the PTV for an individual patient was less than 3% in 88% of cases and less than 2% in 72% of the cases. The differences were larger in those patients where the dose distribution is significantly influenced by the presence of lungs or air gaps. For each series of patients the mean difference between the ICRU reference dose and the mean dose to the PTV was calculated. The difference between these two values never exceeded 2%. Because not all planning systems are able to calculate the mean dose to the PTV, the concept of the mean central dose, the mean of the dose values at the centre of the PTV in each CT slice, has been introduced. The mean central dose was also calculated for the same patients and was closer to the mean dose to the PTV than the ICRU reference dose. Conclusion: The mean dose to the PTV is well estimated by either the ICRU reference dose or the mean central dose for a variety of treatment techniques for common types of cancer

  3. Evaluation of the dose uniformity for double-plane high dose rate interstitial breast implants with the use of dose reference points and dose non-uniformity ratio

    International Nuclear Information System (INIS)

    MAjor, T.; Polgar, C.; Somogyi, A.; Nemeth, G.

    2000-01-01

    This study investigated the influence of dwell time optimizations on dose uniformity characterized by dose values in dose points and dose non-uniformity ratio (DNR) and analyzed which implant parameters have influence on the DNR. Double-plane breast implants with catheters arranged in triangular pattern were used for the calculations. At a typical breast implant, dose values in dose reference points inside the target volume and volumes enclosed by given isodose surfaces were calculated and compared for non-optimized and optimized implants. The same 6-cm treatment length was used for the comparisons. Using different optimizations plots of dose non-uniformity ratio as a function of catheter separation, source step size, number of catheters, length of active sections were drawn and the minimum DNR values were determined. Optimization resulted in less variation in dose values over dose points through the whole volume and in the central plane only compared to the non-optimized case. At implant configurations consisting of seven catheters with 15-mm separation, 5-mm source step size and various active lengths adapted according to the type of optimization, the no optimization, geometrical (volume mode) and dose point (on dose points and geometry) optimization resulted in similar treatment volumes, but an increased high dose volume was observed due to the optimization. The dose non-uniformity ratio always had the minimum at average dose over dose normalization points, defined in the midpoints between the catheters through the implant volume. The minimum value of DNR depended on catheter separation, source step size, active length and number of catheters. The optimization had only a small influence on DNR. In addition to the reference points in the central plane only, dose points positioned in the whole implant volume can be used for evaluating the dose uniformity of interstitial implants. The dose optimization increases not only the dose uniformity within the implant but

  4. Application of diagnostic reference levels in medical practice

    Energy Technology Data Exchange (ETDEWEB)

    Bourguignon, Michel [Faculty of Medicine of Paris, Deputy Director General, Nuclear Safety Authority (ASN), Paris (France)

    2006-07-01

    Diagnosis reference levels (D.R.L.) are defined in the Council Directive 97/43 EURATOM as 'Dose levels in medical radio diagnosis practices or in the case of radiopharmaceuticals, levels of activity, for typical examinations for groups of standards-sized patients or standards phantoms for broadly defined types of equipment. These levels are expected not to be exceeded for standard procedures when good and normal practice regarding diagnostic and technical performance is applied'. Thus D.R.L. apply only to diagnostic procedures and does not apply to radiotherapy. Radiation protection of patients is based on the application of 2 major radiation protection principles, justification and optimization. The justification principle must be respected first because the best way to protect the patient is not to carry a useless test. Radiation protection of the patient is a continuous process and local dose indicator values in the good range should not prevent the radiologist or nuclear medicine physician to continue to optimize their practice. (N.C.)

  5. Application of diagnostic reference levels in medical practice

    International Nuclear Information System (INIS)

    Bourguignon, Michel

    2006-01-01

    Diagnosis reference levels (D.R.L.) are defined in the Council Directive 97/43 EURATOM as 'Dose levels in medical radio diagnosis practices or in the case of radiopharmaceuticals, levels of activity, for typical examinations for groups of standards-sized patients or standards phantoms for broadly defined types of equipment. These levels are expected not to be exceeded for standard procedures when good and normal practice regarding diagnostic and technical performance is applied'. Thus D.R.L. apply only to diagnostic procedures and does not apply to radiotherapy. Radiation protection of patients is based on the application of 2 major radiation protection principles, justification and optimization. The justification principle must be respected first because the best way to protect the patient is not to carry a useless test. Radiation protection of the patient is a continuous process and local dose indicator values in the good range should not prevent the radiologist or nuclear medicine physician to continue to optimize their practice. (N.C.)

  6. Underlying data for derived emergency reference levels

    International Nuclear Information System (INIS)

    Burkhardt, J.; Lux, D.

    1990-09-01

    Among the dose-relevant products, raw milk was the most critical food item for self-supporters during the first 1-2 years after Chernobyl. The relatively high body burden of radiocesium, measured in the group of hunters, can be explained by the fact that large amounts of contamined game are consumed. With respect to internal contamination, mushroom-eaters rank in an intermediate position. The mushroom-eaters reacted to the results from the first whole-body-measurements with special caution by selecting less contaminated wild-mushrooms for meals and by avoiding highly contaminated species, such as Boletus badius. Additionally self-supporters obtain about 75% of dose-relevant foodstuffs from the region. (DG)

  7. Diagnostic reference levels in intraoral dental radiography in Korea

    International Nuclear Information System (INIS)

    Kim, Eun Kyung; Han, Won Jeong; Choi, Jin Woo; Jung, Yun Hoa; Yoon, Suk Ja; Lee, Jae Seo

    2012-01-01

    The objectives of this study were to survey the radiographic exposure parameters, to measure the patient doses for intraoral dental radiography nationwide, and thus to establish the diagnostic reference levels (DRLs) in intraoral dental X-ray examination in Korea. One hundred two intraoral dental radiographic machines from all regions of South Korea were selected for this study. Radiographic exposure parameters, size of hospital, type of image receptor system, installation duration of machine, and type of dental X-ray machine were documented. Patient entrance doses (PED) and dose-area products (DAP) were measured three times at the end of the exit cone of the X-ray unit with a DAP meter (DIAMENTOR M4-KDK, PTW, Freiburg, Germany) for adult mandibular molar intraoral dental radiography, and corrections were made for room temperature and pressure. Measured PED and DAP were averaged and compared according to the size of hospital, type of image receptor system, installation duration, and type of dental X-ray machine. The mean exposure parameters were 62.6 kVp, 7.9 mA, and 0.5 second for adult mandibular molar intraoral dental radiography. The mean patient dose was 2.11 mGy (PED) and 59.4 mGycm2 (DAP) and the third quartile one 3.07 mGy (PED) and 87.4 mGycm 2 (DAP). Doses at university dental hospitals were lower than those at dental clinics (p 2 (DAP) as the DRLs in adult mandibular molar intraoral dental radiography in Korea.

  8. Diagnostic radiography dose and guidance levels

    International Nuclear Information System (INIS)

    Cuadros, M.; Augusto, A.

    2001-01-01

    This work shows a study done on conventional radiodiagnostic equipment. The evaluation was implemented throughout different areas of Bolivia, covering not only single equipment radiographs used in the cities, but also the ones used in rural areas. There have been more than 90 equipment pieces evaluated of which the dose received by a patient for a given exam has been considered an essential element. For this purpose two types of examinations have been selected, these being considered the more frequent. Not only the dose aspect was taken into consideration but the technique used as well. These elements that support very important information have been related to orientative levels. (author)

  9. A system for environmental protection. Reference dose models for fauna and flora

    International Nuclear Information System (INIS)

    Pentreath, R.J.; Woodhead, D.S.

    2000-01-01

    Ideas have already been published on how the current problems relating to environmental protection could be explicitly addressed. One of the basic cornerstones of the proposed system is that of the use of reference dose models for fauna and flora, in a manner analogous to those used for the human species. The concept is that, for a number of both aquatic and terrestrial fauna and flora types, 'reference' dose models, and dose per unit (internal and external) exposure tables, could be compiled. These would then be used to draw broad conclusions on the likely effects for such organisms in relation to three broad environment end points of concern: life shortening; impairment of reproductive capacity; and scorable, cytogenetic damage. The level of complexity of the dose models needs to be commensurate with the morphological complexity of the modelled organism, its size, and the data bases which are either available or could be reasonably obtained. The most basic models considered are either solid ellipsoids or spheres, with fixed dimensions. Secondary models contain internal, but relatively simple geometric features representative of those key organs or tissues for which more precise estimates of dose are required. Their level of complexity is also a function of different internal and external sources of radiation, and expected differences in radiosensitivities. Tertiary models -of greater complexity- are only considered to be of value for higher vertebrates. The potential derivation and use of all three sets of models is briefly discussed. (author)

  10. Studies on the reference Korean and estimation of radiation exposure dose

    International Nuclear Information System (INIS)

    Kim, Y.J.; Lee, K.S.; Chun, K.J.; Kim, J.B.; Chung, G.H.; Kim, S.R.

    1982-01-01

    For the purpose of establishment of Reference Korean and estimation of internal and external exposure doses in the Reference Korean, we have surveyed reference values for Koreans such as physical standards including height, weight, and body surface area, food consumption rate of daily intake of radioactive substances and exposure dose from natural radiation. (Author)

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

    Directory of Open Access Journals (Sweden)

    A. V. Vodovatov

    2013-01-01

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

  12. Fluoroscopy in paediatric fractures - Setting a local diagnostic reference level

    International Nuclear Information System (INIS)

    Pillai, A.; McAuley, A.; McMurray, K.; Jain, M.

    2006-01-01

    Background: The ionizing radiations (Medical Exposure) Regulation 2000 has made it mandatory to establish diagnostic reference levels (DRLs) for all typical radiological examinations. Objectives: We attempt to provide dose data for some common fluoroscopic procedures used in orthopaedic trauma that may be used as the basis for setting DRLs for paediatric patients. Materials and methods: The dose area product (DAP) in 865 paediatric trauma examinations was analysed. Median DAP values and screening times for each procedure type along with quartile values for each range are presented. Results: In the upper limb, elbow examinations had maximum exposure with a median DAP value of 1.21 cGy cm 2 . Median DAP values for forearm and wrist examinations were 0.708 and 0.538 cGy cm 2 , respectively. In lower limb, tibia and fibula examinations had a median DAP value of 3.23 cGy cm 2 followed by ankle examinations with a median DAP of 3.10 cGy cm 2 . The rounded third quartile DAP value for each distribution can be used as a provisional DRL for the specific procedure type. (authors)

  13. Dose management for X-ray and CT. Systematic comparison of exposition values from two institutes to diagnostic reference levels and use of results for optimisation of exposition; Dosismanagement fuer konventionelles Roentgen und CT. Systematischer Vergleich der Expositionswerte zweier radiologischer Institute mit den diagnostischen Referenzwerten und Verwendung der Ergebnisse zur Optimierung der Strahlenexposition bei diagnostischen Untersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, S.; Alejandre-Lafont, E.; Krombach, G.A. [University Hospital Giessen (Germany). Dept. of Radiology; Schmidt, T. [University Hospital Giessen (Germany). Dept. of Neuroradiology; Gizewski, E.R. [University Hospital Innsbruck (Austria). Dept. of Neuroradiology; Fiebich, M. [University of Applied Sciences, Giessen (Germany). Inst. of Medical Physics and Radiation Protection

    2014-08-15

    Purpose: In 2 institutions exposure values were evaluated and compared with the 2010 updated diagnostic reference levels (DRL) and possibilities for decreasing the dose assessed. Materials and Methods: Mean exposure values obtained during a 3-month period were calculated for all modalities (X-ray: imaging plate system and digital detector; dual-source 64- and 16- slice spiral CT) as well as examination types were compared to old diagnostic reference levels in addition to DRLs introduced in 2010. Then 10 examinations of all modalities and types were accompanied by a medical physicist and optimized stepwise if necessary. Results: The mean values of X-ray examinations were above DRL. All accompanied examinations were beyond DRL except lateral lumbar spine (LSP) and lateral thoracic X-ray, which were elevated due to statistical outliers from morbidly obese patients or patients with metallic implants. For a-p LSP tube voltage was increased. While image quality was maintained, dose area product (DAP) was reduced by 50% to 123 ±61 cGy.cm{sup 2} for LSP a-p and 30% for lateral LSP to 229 ± 116 cGy.cm{sup 2}. For CT examinations, dose was below DRL. Accompanied examinations of the lumbar spine performed on a 16-slice spiral CT demonstrated a result 68% above DRL with dose length product (DLP) of 840 ± 252 cGy . cm. For optimization, pitch and tube voltage were stepwise increased and DLP reduced below DRL. Conclusion: Systematic analysis of our internal exposure values on the occasion of adaptation of DRL is crucial for prompt detection of exceeded values independently from assessment by the responsible authority and initiation of proper measures for decreasing exposure dose. Hereby active dose management is attained. (orig.)

  14. Dose level of occupational exposure in China

    International Nuclear Information System (INIS)

    Tian, Y.; Zhang, L.; Ju, Y.

    2008-01-01

    This paper discusses the dose level of Chinese occupational exposures during 1986-2000. Data on occupational exposures from the main categories in nuclear fuel cycle (uranium enrichment and conversion, fuel fabrication, reactor operation, waste management and research activity, except for uranium mining and milling because of the lack of data), medical uses of radiation (diagnostic radiation, nuclear medicine and radiotherapy) and industrial uses of radiation (industrial radiography and radioisotope production) are presented and summarised in detail. These are the main components of occupational exposures in China. In general, the average annual effective doses show a steady decreasing trend over periods: from 2.16 to 1.16 mSv in medical uses of radiation during 1990-2000; from 1.92 to 1.18 mSv in industrial radiography during 1990-2000; from 8.79 to 2.05 mSv in radioisotope production during the period 1980-2000. Almost all the average annual effective doses in discussed occupations were lower than 5 mSv in recent years (except for well-logging: 6.86 mSv in 1999) and no monitored workers were found to have received the occupational exposure exceeding 50 mSv in a single year or 100 mSv in a five-year period. So the Chinese protection status of occupation exposure has been improved in recent years. However, the average annual effective doses in some occupations, such as diagnostic radiology and coal mining, were still much higher than that of the whole world. There are still needs for further improvement and careful monitoring of occupational exposure to protect every worker from excessive occupational exposure, especially for the workers who were neglected before. (authors)

  15. The establishment of local diagnostic reference levels for paediatric interventional cardiology

    International Nuclear Information System (INIS)

    McFadden, S.; Hughes, C.; D'Helft, C.I.; McGee, A.; Rainford, L.; Brennan, P.C.; McCrum-Gardner, E.; Winder, R.J.

    2013-01-01

    Background: There is a paucity of information worldwide on radiation exposure in paediatric interventional cardiology. At present Nationally established Diagnostic Reference Levels exist for adult interventional cardiology procedures in the UK but little data is available for paediatrics. In addition, interventional cardiology has been identified as one the highest contributors to medical exposure to ionising radiation and children are more radiosensitive than adults. Objective: This study sought to determine current radiation dose levels in paediatric interventional cardiology (IC) with a view to establishing local diagnostic reference levels (LDRL). Methods: Radiation dose and examination details were recorded for 354 paediatric patients examined by IC in a specialised paediatric centre in Europe. Radiation doses were recorded using a Dose Area Product meter along with examination details. Procedures were categorised as either diagnostic (A) or therapeutic (B). Data was further sub-divided into five age ranges; (1) newborn <1 year (2) 1 <5 years (3) 5 <10 years (4) 10 <15 years (5) 15 years and over. Proposed LDRL were calculated from the mean dose area product readings. Results: The mean patient age was 2.6 years (range 0.0 days–16 years) and weight was 14.9 kg (range 2.4–112 kg). LDRL for the five age groupings were calculated as 190, 421, 582, 1289 and 1776 cGycm² respectively. Conclusion: Local dose reference levels have been proposed for paediatric IC and can be used as a benchmark for other hospitals to compare against their own radiation doses

  16. Establishment of Reference Doses for residues of allergenic foods: Report of the VITAL Expert Panel

    NARCIS (Netherlands)

    Taylor, S.L.; Baumert, J.L.; Kruizinga, A.G.; Remington, B.C.; Crevel, R.W.R.; Brooke-Taylor, S.; Allen, K.J.; Houben, G.

    2014-01-01

    In 2011, an expert panel was assembled to establish appropriate Reference Doses for allergenic food residues as a part of the VITAL (Voluntary Incidental Trace Allergen Labeling) program of The Allergen Bureau of Australia & New Zealand (ABA). These Reference Doses would guide advisory labeling

  17. SU-E-P-10: Establishment of Local Diagnostic Reference Levels of Routine Exam in Computed Tomography

    International Nuclear Information System (INIS)

    Yeh, M; Wang, Y; Weng, H

    2015-01-01

    Introduction National diagnostic reference levels (NDRLs) can be used as a reference dose of radiological examination can provide radiation dose as the basis of patient dose optimization. Local diagnostic reference levels (LDRLs) by periodically view and check doses, more efficiency to improve the way of examination. Therefore, the important first step is establishing a diagnostic reference level. Computed Tomography in Taiwan had been built up the radiation dose limit value,in addition, many studies report shows that CT scan contributed most of the radiation dose in different medical. Therefore, this study was mainly to let everyone understand DRL’s international status. For computed tomography in our hospital to establish diagnostic reference levels. Methods and Materials: There are two clinical CT scanners (a Toshiba Aquilion and a Siemens Sensation) were performed in this study. For CT examinations the basic recommended dosimetric quantity is the Computed Tomography Dose Index (CTDI). Each exam each different body part, we collect 10 patients at least. Carried out the routine examinations, and all exposure parameters have been collected and the corresponding CTDIv and DLP values have been determined. Results: The majority of patients (75%) were between 60–70 Kg of body weight. There are 25 examinations in this study. Table 1 shows the LDRL of each CT routine examination. Conclusions: Therefore, this study would like to let everyone know DRL’s international status, but also establishment of computed tomography of the local reference levels for our hospital, and providing radiation reference, as a basis for optimizing patient dose

  18. SU-E-P-10: Establishment of Local Diagnostic Reference Levels of Routine Exam in Computed Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, M; Wang, Y; Weng, H [Chiayi Chang Gung Memorial Hospital of The C.G.M.F, Puzi City, Chiayi County, Taiwan (China)

    2015-06-15

    Introduction National diagnostic reference levels (NDRLs) can be used as a reference dose of radiological examination can provide radiation dose as the basis of patient dose optimization. Local diagnostic reference levels (LDRLs) by periodically view and check doses, more efficiency to improve the way of examination. Therefore, the important first step is establishing a diagnostic reference level. Computed Tomography in Taiwan had been built up the radiation dose limit value,in addition, many studies report shows that CT scan contributed most of the radiation dose in different medical. Therefore, this study was mainly to let everyone understand DRL’s international status. For computed tomography in our hospital to establish diagnostic reference levels. Methods and Materials: There are two clinical CT scanners (a Toshiba Aquilion and a Siemens Sensation) were performed in this study. For CT examinations the basic recommended dosimetric quantity is the Computed Tomography Dose Index (CTDI). Each exam each different body part, we collect 10 patients at least. Carried out the routine examinations, and all exposure parameters have been collected and the corresponding CTDIv and DLP values have been determined. Results: The majority of patients (75%) were between 60–70 Kg of body weight. There are 25 examinations in this study. Table 1 shows the LDRL of each CT routine examination. Conclusions: Therefore, this study would like to let everyone know DRL’s international status, but also establishment of computed tomography of the local reference levels for our hospital, and providing radiation reference, as a basis for optimizing patient dose.

  19. Data base of dose coefficients called ecrin-V1-internet reference handbook; Base de donnees de coefficients de dose ecrin-V1-internet manuel de reference

    Energy Technology Data Exchange (ETDEWEB)

    Perrin, M.L

    2003-07-01

    The objective of this data base is to dispose on a only computer medium the values of radiation doses allowing to guarantee the tracing and the coherence of radiation doses received by man. These data are usable to evaluate the risks in the frame of studies or expertise. They include the doses coming from external irradiations, internal contamination by inhalation or ingestion and receive by workers or public. The definitions and reference values come from international publications (the list is given). (N.C.)

  20. Determination of carbon-14 in environmental level, solid reference materials

    Energy Technology Data Exchange (ETDEWEB)

    Blowers, Paul, E-mail: paul.blowers@cefas.co.uk [Cefas Lowestoft Laboratory, Pakefield Road, Lowestoft, Suffolk, NR33 0HT (United Kingdom); Caborn, Jane, E-mail: jane.a.caborn@nnl.co.uk [NNL, Springfields, Salwick, Preston, Lancashire, PR4 0XJ (United Kingdom); Dell, Tony [Veterinary Laboratories Agency, New Haw, Addlestone, Surrey, KT15 3NB (United Kingdom); Gingell, Terry [DSTL, Radiation Protection Services, Crescent Road, Alverstoke, Gosport, Hants, PO12 2DL (United Kingdom); Harms, Arvic [National Physical Laboratory, Hampton Road, Teddington, Middlesex, TW11 0LW (United Kingdom); Long, Stephanie [Radiological Protection Institute of Ireland, 3 Clonskeagh Square, Clonskeagh Road, Dublin 14, Ireland (United Kingdom); Sleep, Darren [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, LA1 4AP (United Kingdom); Stewart, Charlie [UKAEA (Waste Management Group), Chemical Support Services, D1310/14, Dounreay, Thurso, Caithness, KW14 7TZ (United Kingdom); Walker, Jill [Radiocarbon Dating, The Old Stables, East Lockinge, Wantage, Oxon OX12 8QY (United Kingdom); Warwick, Phil E. [GAU-Radioanalytical, National Oceanography Centre Southampton, European Way, Southampton, SO14 3ZH (United Kingdom)

    2011-10-15

    An intercomparison exercise to determine the {sup 14}C activity concentrations in a range of solid, environmental level materials was conducted between laboratories in the UK. IAEA reference materials, C2, C6 and C7, and an in-house laboratory QA material were dispatched in 2006 to ten laboratories comprising of members of the Analyst Informal Working Group (AIWG) and one other invited party. The laboratories performed the determinations using a number of techniques, and using the results each one was evaluated in terms of levels of precision, sensitivity and limits of detection. The results of the study show that all techniques are capable of successfully analysing {sup 14}C in environmental level materials, however, a shortage of certified environmental reference materials exists. The suitability of the IAEA reference materials and other material for use as reference materials was also assessed.

  1. Determination of carbon-14 in environmental level, solid reference materials

    International Nuclear Information System (INIS)

    Blowers, Paul; Caborn, Jane; Dell, Tony; Gingell, Terry; Harms, Arvic; Long, Stephanie; Sleep, Darren; Stewart, Charlie; Walker, Jill; Warwick, Phil E.

    2011-01-01

    An intercomparison exercise to determine the 14 C activity concentrations in a range of solid, environmental level materials was conducted between laboratories in the UK. IAEA reference materials, C2, C6 and C7, and an in-house laboratory QA material were dispatched in 2006 to ten laboratories comprising of members of the Analyst Informal Working Group (AIWG) and one other invited party. The laboratories performed the determinations using a number of techniques, and using the results each one was evaluated in terms of levels of precision, sensitivity and limits of detection. The results of the study show that all techniques are capable of successfully analysing 14 C in environmental level materials, however, a shortage of certified environmental reference materials exists. The suitability of the IAEA reference materials and other material for use as reference materials was also assessed.

  2. Reappraisal of the reference dose distribution in the UNSCEAR 1977 report

    International Nuclear Information System (INIS)

    Kumazawa, Shigeru

    2008-01-01

    This paper provides the update of the reference dose distribution proposed by G.A.M. Web and D. Beninson in Annex E to the UNSCEAR 1977 Report. To demonstrate compliance with regulatory obligations regarding doses to individuals, they defined it with the following properties: 1) The distribution of annual doses is log-normal; 2) The mean of the annual dose distribution is 5 m Gy (10% of the ICRP 1977 dose limit); 3) The proportion of workers exceeding 50 m Gy is 0.1%. The concept of the reference dose distribution is still important to understand the inherent variation of individual doses to workers controlled by source-related and individual-related efforts of best dose reduction. In the commercial nuclear power plant, the dose distribution becomes the more apart from the log-normal due to the stronger ALARA efforts and the revised dose limits. The monitored workers show about 1 m Sv of annual mean and far less than 0.1% of workers above 20 m Sv. The updated models of dose distribution consist of log-normal (no feedback on dose X) ln(X)∼N(μ,σ 2 ), hybrid log-normal (feedback on higher X by ρ) hyb(ρX)=ρX+ln(ρX)∼N(μ,σ 2 ), hybrid S B (feedback on higher dose quotient X/(D-X) not close to D by ρ) hyb[ρX/(D.X)]∼N(μ,σ 2 ) and Johnson's S B (limit to D) ln[X/(D-X)]∼N(μ,σ 2 ). These models afford interpreting the degree of dose control including dose constraint/limit to the reference distribution. Some of distributions are examined to characterize the variation of doses to members of the public with uncertainty. (author)

  3. Comparison of Hemoglobin Levels Before and After Hemodialysis and Their Effects on Erythropoietin Dosing and Cost

    OpenAIRE

    Sagheb; Fallahzadeh; Moaref; Fallahzadeh; Dormanesh

    2016-01-01

    Background Hemoglobin levels measured after hemodialysis, as compared to hemoglobin levels measured before hemodialysis, are suggested to be a more accurate reflection of the hemoglobin levels between hemodialysis sessions, and to be a better reference point for adjusting erythropoietin dosing. Objectives The aim of this study was to compare the hemoglobin levels before and after hemodialysis, to calculate the required erythropoie...

  4. The Basic Principles in Assessment and Selection of Reference Doses: Considerations in Nuclear Medicine (invited paper)

    International Nuclear Information System (INIS)

    Mattsson, S.; Jacobsson, L.; Vestergren, E.

    1998-01-01

    The possible ways to optimise the relation between diagnostic information and patient absorbed dose differ between nuclear medicine and X ray imaging. In nuclear medicine, very little has been done to find an optimal dosage of radiopharmaceuticals. Current nuclear medicine methods are discussed in the light of the recent ICRP Publications and the new EU Patient Directive. The paper also discusses how reference levels for administered activity may be derived from patient studies. In order to eliminate the most inappropriate choices (too low or too high activities), knowledge of the current statistical distribution of administered activities may be helpful. Different methods to estimate the amount of activity that should be administered to children of various body sizes to guarantee the same image quality as for adults are also discussed. Examples of current activity levels for common nuclear medicine procedures, indicating the state of the practice, are given. (author)

  5. Reference hearing threshold levels for short duration signals

    DEFF Research Database (Denmark)

    Poulsen, Torben; Legarth, Søren Vase

    2008-01-01

    for the determination of reference hearing threshold levels. The results are given as peak-to-peak equivalent threshold sound pressure levels (peETSPL). The results are in good agreement with other sparse results from literature and are part of the basis for the ISO 389-6 standard from 2007....

  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. Remarks on reporting and recording consistent with the ICRU Reference Dose

    Directory of Open Access Journals (Sweden)

    Gainey Mark

    2009-10-01

    Full Text Available Abstract Background ICRU 50/62 provides a framework to facilitate the reporting of external beam radiotherapy treatments from different institutions. A predominant role is played by points that represent "the PTV dose". However, for new techniques like Intensity Modulated Radiotherapy (IMRT - especially step and shoot IMRT - it is difficult to define a point whose dose can be called "characteristic" of the PTV dose distribution. Therefore different volume based methods of reporting of the prescribed dose are in use worldwide. Several of them were compared regarding their usability for IMRT and compatibility with the ICRU Reference Point dose for conformal radiotherapy (CRT in this study. Methods The dose distributions of 45 arbitrarily chosen volumes treated by CRT plans and 57 volumes treated by IMRT plans were used for comparison. Some of the IMRT methods distinguish the planning target volume (PTV and its central part PTVx (PTV minus a margin region of × mm. The reporting of dose prescriptions based on mean and median doses together with the dose to 95% of the considered volume (D95 were compared with each other and in respect of a prescription report with the aid of one or several possible ICRU Reference Points. The correlation between all methods was determined using the standard deviation of the ratio of all possible pairs of prescription reports. In addition the effects of boluses and the characteristics of simultaneous integrated boosts (SIB were examined. Results Two types of methods result in a high degree of consistency with the hitherto valid ICRU dose reporting concept: the median dose of the PTV and the mean dose to the central part of the PTV (PTVx. The latter is similar to the CTV, if no nested PTVs are used and no patient model surfaces are involved. A reporting of dose prescription using the CTV mean dose tends to overestimate the plateau doses of the lower dose plateaus of SIB plans. PTVx provides the possibility to approach

  8. Remarks on reporting and recording consistent with the ICRU Reference Dose

    International Nuclear Information System (INIS)

    Bratengeier, Klaus; Oechsner, Markus; Gainey, Mark; Flentje, Michael

    2009-01-01

    ICRU 50/62 provides a framework to facilitate the reporting of external beam radiotherapy treatments from different institutions. A predominant role is played by points that represent 'the PTV dose'. However, for new techniques like Intensity Modulated Radiotherapy (IMRT) - especially step and shoot IMRT - it is difficult to define a point whose dose can be called 'characteristic' of the PTV dose distribution. Therefore different volume based methods of reporting of the prescribed dose are in use worldwide. Several of them were compared regarding their usability for IMRT and compatibility with the ICRU Reference Point dose for conformal radiotherapy (CRT) in this study. The dose distributions of 45 arbitrarily chosen volumes treated by CRT plans and 57 volumes treated by IMRT plans were used for comparison. Some of the IMRT methods distinguish the planning target volume (PTV) and its central part PTV x (PTV minus a margin region of × mm). The reporting of dose prescriptions based on mean and median doses together with the dose to 95% of the considered volume (D 95 ) were compared with each other and in respect of a prescription report with the aid of one or several possible ICRU Reference Points. The correlation between all methods was determined using the standard deviation of the ratio of all possible pairs of prescription reports. In addition the effects of boluses and the characteristics of simultaneous integrated boosts (SIB) were examined. Two types of methods result in a high degree of consistency with the hitherto valid ICRU dose reporting concept: the median dose of the PTV and the mean dose to the central part of the PTV (PTV x ). The latter is similar to the CTV, if no nested PTVs are used and no patient model surfaces are involved. A reporting of dose prescription using the CTV mean dose tends to overestimate the plateau doses of the lower dose plateaus of SIB plans. PTV x provides the possibility to approach biological effects

  9. Dose levels in conventional X-rays

    International Nuclear Information System (INIS)

    Guerra M, J. A.; Gonzalez G, J. A.; Pinedo S, A.; Salas L, M. A.; Vega C, H. R.; Rivera M, T.; Azorin N, J.

    2009-10-01

    There were a series of measures in the General Hospital of Fresnillo in the X-ray Department in the areas of X-1 and X-2-ray rooms and in the neonatal intensive care unit 2, was determined the dose surface entry in eyes, thyroid and gonads for patients undergoing to X-ray study of chest Tele by thermoluminescent dosimetry. Five dosemeters were used in each one of the scans; so find the following dose ranges 20 + - 23 mGy to 350 + - 41 mGy. With the results obtained we can conclude that the procedures used and the equipment calibration is adequate. (Author)

  10. Low level dose induced chromosome aberrations in human blood lymphocytes

    International Nuclear Information System (INIS)

    Pohl-Rueling, J.

    1992-01-01

    Unstable structural aberrations in chromosomes of human blood lymphocytes cannot be used as biological dosemeters in the low dose range, when extrapolating from high doses using a linear dose response, as required by the original formula of the dual radiation action theory. A survey is given of experimental dose-response curves of chromosome aberrations, obtained in investigations not only by this institute, in cooperation with many other laboratories, but also by various authors in different areas of the world. The results are not compatible with the predicted linear dose relationships at in vivo dose ranges up to 30 mGy.y -1 . The aberration frequencies rise sharply with dose within the normal environmental exposure up to about twice that level. At higher doses, aberration frequencies increase less rapidly and reach a plateau. Some in vitro experiments of various authors with higher doses of low LET radiations, up to about 400 mGy have found dose responses with steps. (author)

  11. Process control and dosimetry applied to establish a relation between reference dose measurements and actual dose distribution

    International Nuclear Information System (INIS)

    Ehlerman, D.A.E.

    2001-01-01

    The availability of the first commercial dose level indicator prompted attempts to verify radiation absorbed dose to items under quarantine control (e.g. for insect disinfestation) by some indicator attached to these items. Samples of the new commercial dose level indicators were tested for their metrological properties using gamma and electron irradiation. The devices are suitable for the intended purpose and the subjective judgement whether the threshold dose was surpassed is possible in a reliable manner. The subjective judgements are completely backed by the instrumental results. Consequently, a prototype reader was developed; first tests were successful. The value of dose level indicators and the implications of its use for food or quarantine inspection depends on a link between dose measured (indicated) at the position of such indicator and the characteristic parameters of the frequency distribution of dose throughout the product load i.e. a box or a container or a whole batch of multiple units. Therefore, studies into variability and statistical properties of dose distributions obtained under a range of commercial situations were undertaken. Gamma processing at a commercial multipurpose contract irradiator, electron processing and bremsstrahlung applications at a largescale research facility were included; products were apples, potatoes, wheat, maize, pistachio. Studies revealed that still more detailed information on irradiation geometries are needed in order to render meaningful information from dose label indicators. (author)

  12. Process control and dosimetry applied to establish a relation between reference dose measurements and actual dose distribution

    Energy Technology Data Exchange (ETDEWEB)

    Ehlerman, D A.E. [Institute of Process Engineering, Federal Research Centre for Nutrition, Karlsruhe (Germany)

    2001-03-01

    The availability of the first commercial dose level indicator prompted attempts to verify radiation absorbed dose to items under quarantine control (e.g. for insect disinfestation) by some indicator attached to these items. Samples of the new commercial dose level indicators were tested for their metrological properties using gamma and electron irradiation. The devices are suitable for the intended purpose and the subjective judgement whether the threshold dose was surpassed is possible in a reliable manner. The subjective judgements are completely backed by the instrumental results. Consequently, a prototype reader was developed; first tests were successful. The value of dose level indicators and the implications of its use for food or quarantine inspection depends on a link between dose measured (indicated) at the position of such indicator and the characteristic parameters of the frequency distribution of dose throughout the product load i.e. a box or a container or a whole batch of multiple units. Therefore, studies into variability and statistical properties of dose distributions obtained under a range of commercial situations were undertaken. Gamma processing at a commercial multipurpose contract irradiator, electron processing and bremsstrahlung applications at a largescale research facility were included; products were apples, potatoes, wheat, maize, pistachio. Studies revealed that still more detailed information on irradiation geometries are needed in order to render meaningful information from dose label indicators. (author)

  13. Referent 3D tumor model at cellular level in radionuclide therapy

    International Nuclear Information System (INIS)

    Spaic, R.; Ilic, R.D.; Petrovic, B.J.

    2002-01-01

    Aim Conventional internal dosimetry has a lot of limitations because of tumor dose nonuniformity. The best approach for absorbed dose at cellular level for different tumors in radionuclide therapy calculation is Monte Carlo method. The purpose of this study is to introduce referent tumor 3D model at cellular level for Monte Carlo simulation study in radionuclide therapy. Material and Methods The moment when tumor is detectable and when same therapy can start is time period in which referent 3D tumor model at cellular level was defined. In accordance with tumor growth rate at that moment he was a sphere with same radius (10 000 μm). In that tumor there are cells or cluster of cells, which are randomly distributed spheres. Distribution of cells/cluster of cells can be calculated from histology data but it was assumed that this distribution is normal with the same mean value and standard deviation (100±50 mm). Second parameter, which was selected to define referent tumor, is volume density of cells (30%). In this referent tumor there are no necroses. Stroma is defined as space between spheres with same concentration of materials as in spheres. Results: Referent tumor defined on this way have about 2,2 10 5 cells or cluster of cells random distributed. Using this referent 3D tumor model and for same concentration of radionuclides (1:100) and energy of beta emitters (1000 keV) which are homogeneously distributed in labeled cells absorbed dose for all cells was calculated. Simulations are done using FOTELP Monte Carlo code, which is modified for this purposes. Results of absorbed dose in cells are given in numerical values (1D distribution) and as the images (2D or 3D distributions). Conclusion Geometrical module for Monte Carlo simulation study can be standardized by introducing referent 3D tumor model at cellular level. This referent 3D tumor model gives most realistic presentation of different tumors at the moment of their detectability. Referent 3D tumor model at

  14. An N+3 Technology Level Reference Propulsion System

    Science.gov (United States)

    Jones, Scott M.; Haller, William J.; Tong, Michael To-Hing

    2017-01-01

    An N+3 technology level engine, suitable as a propulsion system for an advanced single-aisle transport, was developed as a reference cycle for use in technology assessment and decision-making efforts. This reference engine serves three main purposes: it provides thermodynamic quantities at each major engine station, it provides overall propulsion system performance data for vehicle designers to use in their analyses, and it can be used for comparison against other proposed N+3 technology-level propulsion systems on an equal basis. This reference cycle is meant to represent the expected capability of gas turbine engines in the N+3 timeframe given reasonable extrapolations of technology improvements and the ability to take full advantage of those improvements.

  15. Effect of radiation dose level on the detectability of pulmonary nodules in chest tomosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Asplund, Sara A.; Svalkvist, Angelica; Maansson, Lars Gunnar; Baath, Magnus [University of Gothenburg, Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy, Gothenburg (Sweden); Sahlgrenska University Hospital, Department of Medical Physics and Biomedical Engineering, Gothenburg (Sweden); Johnsson, Aase A.; Vikgren, Jenny; Flinck, Agneta; Boijsen, Marianne; Fisichella, Valeria A. [University of Gothenburg, Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, Gothenburg (Sweden); Sahlgrenska University Hospital, Department of Radiology, Gothenburg (Sweden)

    2014-07-15

    To investigate the detectability of pulmonary nodules in chest tomosynthesis at reduced radiation dose levels. Eighty-six patients were included in the study and were examined with tomosynthesis and computed tomography (CT). Artificial noise was added to simulate that the tomosynthesis images were acquired at dose levels corresponding to 12, 32, and 70 % of the default setting effective dose (0.12 mSv). Three observers (with >20, >20 and three years of experience) read the tomosynthesis cases for presence of nodules in a free-response receiver operating characteristics (FROC) study. CT served as reference. Differences between dose levels were calculated using the jack-knife alternative FROC (JAFROC) figure of merit (FOM). The JAFROC FOM was 0.45, 0.54, 0.55, and 0.54 for the 12, 32, 70, and 100 % dose levels, respectively. The differences in FOM between the 12 % dose level and the 32, 70, and 100 % dose levels were 0.087 (p = 0.006), 0.099 (p = 0.003), and 0.093 (p = 0.004), respectively. Between higher dose levels, no significant differences were found. A substantial reduction from the default setting dose in chest tomosynthesis may be possible. In the present study, no statistically significant difference in detectability of pulmonary nodules was found when reducing the radiation dose to 32 %. (orig.)

  16. Effect of radiation dose level on the detectability of pulmonary nodules in chest tomosynthesis

    International Nuclear Information System (INIS)

    Asplund, Sara A.; Svalkvist, Angelica; Maansson, Lars Gunnar; Baath, Magnus; Johnsson, Aase A.; Vikgren, Jenny; Flinck, Agneta; Boijsen, Marianne; Fisichella, Valeria A.

    2014-01-01

    To investigate the detectability of pulmonary nodules in chest tomosynthesis at reduced radiation dose levels. Eighty-six patients were included in the study and were examined with tomosynthesis and computed tomography (CT). Artificial noise was added to simulate that the tomosynthesis images were acquired at dose levels corresponding to 12, 32, and 70 % of the default setting effective dose (0.12 mSv). Three observers (with >20, >20 and three years of experience) read the tomosynthesis cases for presence of nodules in a free-response receiver operating characteristics (FROC) study. CT served as reference. Differences between dose levels were calculated using the jack-knife alternative FROC (JAFROC) figure of merit (FOM). The JAFROC FOM was 0.45, 0.54, 0.55, and 0.54 for the 12, 32, 70, and 100 % dose levels, respectively. The differences in FOM between the 12 % dose level and the 32, 70, and 100 % dose levels were 0.087 (p = 0.006), 0.099 (p = 0.003), and 0.093 (p = 0.004), respectively. Between higher dose levels, no significant differences were found. A substantial reduction from the default setting dose in chest tomosynthesis may be possible. In the present study, no statistically significant difference in detectability of pulmonary nodules was found when reducing the radiation dose to 32 %. (orig.)

  17. Establishment of multi-slice computed tomography (MSCT) reference level in Johor, Malaysia

    Science.gov (United States)

    Karim, M. K. A.; Hashim, S.; Bakar, K. A.; Muhammad, H.; Sabarudin, A.; Ang, W. C.; Bahruddin, N. A.

    2016-03-01

    Radiation doses from computed tomography (CT) are the highest and most hazardous compared to other imaging modalities. This study aimed to evaluate radiation dose in Johor, Malaysia to patients during computed tomography examinations of the brain, chest and abdomen and to establish the local diagnostic reference levels (DRLs) as are present with the current, state- of-art, multi-slice CT scanners. Survey forms were sent to five centres performing CT to obtain data regarding acquisition parameters as well as the dose information from CT consoles. CT- EXPO (Version 2.3.1, Germany) was used to validate the dose information. The proposed DRLs were indicated by rounding the third quartiles of whole dose distributions where mean values of CTDIw (mGy), CTDIvol (mGy) and DLP (mGy.cm) were comparable with other reference levels; 63, 63, and 1015 respectively for CT Brain; 15, 14, and 450 respectively for CT thorax and 16, 17, and 590 respectively for CT abdomen. The study revealed that the CT practice and dose output were revolutionised, and must keep up with the pace of introductory technology. We suggest that CTDIvol should be included in current national DRLs, as modern CTs are configured with a higher number of detectors and are independent of pitch factors.

  18. Establishment of multi-slice computed tomography (MSCT) reference level in Johor, Malaysia

    International Nuclear Information System (INIS)

    Karim, M K A; Hashim, S; Ang, W C; Bahruddin, N A; Bakar, K A; Muhammad, H; Sabarudin, A

    2016-01-01

    Radiation doses from computed tomography (CT) are the highest and most hazardous compared to other imaging modalities. This study aimed to evaluate radiation dose in Johor, Malaysia to patients during computed tomography examinations of the brain, chest and abdomen and to establish the local diagnostic reference levels (DRLs) as are present with the current, state- of-art, multi-slice CT scanners. Survey forms were sent to five centres performing CT to obtain data regarding acquisition parameters as well as the dose information from CT consoles. CT- EXPO (Version 2.3.1, Germany) was used to validate the dose information. The proposed DRLs were indicated by rounding the third quartiles of whole dose distributions where mean values of CTDI w (mGy), CTDI vol (mGy) and DLP (mGy.cm) were comparable with other reference levels; 63, 63, and 1015 respectively for CT Brain; 15, 14, and 450 respectively for CT thorax and 16, 17, and 590 respectively for CT abdomen. The study revealed that the CT practice and dose output were revolutionised, and must keep up with the pace of introductory technology. We suggest that CTDI vol should be included in current national DRLs, as modern CTs are configured with a higher number of detectors and are independent of pitch factors. (paper)

  19. Establishment of local Diagnostic Reference Levels (DRLs) for ...

    African Journals Online (AJOL)

    Diagnostic reference levels (DRLs) is an essential optimization tool in radiography and radiological sciences. The objective of the study is to establish DRL for radiography examinations in north eastern Nigeria. A Prospective cross- sectional study conducted in two university teaching hospitals in north eastern Nigeria.

  20. Estimates of diagnostic reference levels for common radiographic x-ray examinations in some sudanese hospitals

    International Nuclear Information System (INIS)

    Awad, Ezdehar Mohammed Satti.

    2016-03-01

    The objective of this study were to estimate patient dose in some common diagnostic x-ray examinations in Sudan with the aim to propose national diagnostic reference levels (DRLs). Radiation doses were estimated for the patients in 23 public hospitals in different town in Sudan (Wad-Madani, Kasala, Atbara Al obaid, Al nhod, Khartoum). Entrance surface air kerma (ESAK) was estimated in a three steps protocol: First, x-ray unit output Y (d) was measured at a distance at a distance (d) for different peak tube voltages and tube loading (mAs). Next, incident air kerma (k) was calculated from Y (d) using inverse square law combined with patient exposure factors. ESAK was calculated from k using backscatter factor, B. Mean ESAK values were comparable to those reported in other countries and are below reference dose levels. The estimated mean ESAK values were: 0.4, 1.9, 1.8, 3.2, 2.4, 3.5, and 8.4 mGy for chests . The estimated mean ESAK values were 0.4, 1.9, 1.8, 3.2, 2.4, 3,5, and 8.4 mGy for chest PA, Skull AP/PA, Skull LAT, Abdomen Pelvis AP, Lumber Spine AP and Lumber Spine LAT examination respectively. The results are used for dose optimization and to propose national diagnostic reference levels. (Author)

  1. The true bladder dose: on average thrice higher than the ICRU reference

    International Nuclear Information System (INIS)

    Barillot, I.; Horiot, J.C.; Maingon, P.; Bone-Lepinoy, M.C.; D'Hombres, A.; Comte, J.; Delignette, A.; Feutray, S.; Vaillant, D.

    1996-01-01

    The aim of this study is to compare ICRU dose to doses at the bladder base located from ultrasonography measurements. Since 1990, the dose delivered to the bladder during utero-vaginal brachytherapy was systematically calculated at 3 or 4 points representative of bladder base determined with ultrasonography. The ICRU Reference Dose (IRD) from films, the Maximum Dose (Dmax), the Mean Dose (Dmean) representative of the dose received by a large area of bladder mucosa, the Reference Dose Rate (RDR) and the Mean Dose Rate (MDR) were recorded. Material: from 1990 to 1994, 198 measurements were performed in 152 patients. 98 patients were treated for cervix carcinomas, 54 for endometrial carcinomas. Methods: Bladder complications were classified using French Italian Syllabus. The influence of doses and dose rates on complications were tested using non parametric t test. Results: On average IRD is 21 Gy +/- 12 Gy, Dmax is 51Gy +/- 21Gy, Dmean is 40 Gy +/16 Gy. On average Dmax is thrice higher than IRD and Dmean twice higher than IRD. The same results are obtained for cervix and endometrium. Comparisons on dose rates were also performed: MDR is on average twice higher than RDR (RDR 48 cGy/h vs MDR 88 cGy/h). The five observed complications consist of incontinence only (3 G1, 1G2, 1G3). They are only statistically correlated with RDR p=0.01 (46 cGy/h in patients without complications vs 74 cGy/h in patients with complications). However the full responsibility of RT remains doubtful and should be shared with surgery in all cases. In summary: Bladder mucosa seems to tolerate well much higher doses than previous recorded without increased risk of severe sequelae. However this finding is probably explained by our efforts to spare most of bladder mucosa by 1 deg. ) customised external irradiation therapy (4 fields, full bladder) 2 deg. ) reproduction of physiologic bladder filling during brachytherapy by intermittent clamping of the Foley catheter

  2. Establishing a reference range for triiodothyronine levels in preterm infants.

    Science.gov (United States)

    Oh, Ki Won; Koo, Mi Sung; Park, Hye Won; Chung, Mi Lim; Kim, Min-ho; Lim, Gina

    2014-10-01

    Thyroid dysfunction affects clinical complications in preterm infants and older children. However, thyroid hormone replacement in preterm infants has no proven benefits, possibly owing to the lack of an appropriate reference range for thyroid hormone levels. We aimed to establish a reference range for triiodothyronine (T3) levels at 1-month postnatal age (PNA) in preterm infants. This retrospective study included preterm infants born at a tertiary referral neonatal center at gestational age (GA)<35 weeks with no apparent thyroid dysfunction, for 6 consecutive years, with follow-up from PNA 2 weeks to 16 weeks. Using thyroid function tests (TFT), the relationships between T3 levels and thyrotropin (TSH) and free thyroxine (fT4) levels, birth weight, GA, postmenstrual age (PMA), and PNA were examined. The conversion trend for fT4 to T3 was analyzed using the T3/fT4 ratio. Overall, 464 TFTs from 266 infants were analyzed, after excluding 65 infants with thyroid dysfunction. T3 levels increased with fT4 levels, birth weight, GA, PMA, and PNA but not with TSH levels. The T3/fT4 ratio also increased with GA, PNA, and PMA. The average T3 level at 1 month PNA was 72.56 ± 27.83 ng/dL, with significant stratifications by GA. Relatively low T3 and fT4 levels in preterm infants were considered normal, with T3 levels and conversion trends increasing with GA, PMA, and PNA. Further studies are required to confirm the role of the present reference range in thyroid hormone replacement therapy. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Environmental policy. Ambient radioactivity levels and radiation doses in 1998

    International Nuclear Information System (INIS)

    1999-11-01

    The report contains information on the natural (background) radiation exposure (chapter II), the natural radiation exposure as influenced by anthropogenic effects (chapter III), the anthropogenic radiation exposure (chapter IV), and the radiation doses to the environment and the population emanating from the Chernobyl fallout (chapter V). The natural radiation exposure is specified referring to the contributions from cosmic and terrestrial background radiation and intake of natural radioactive substances. Changes of the natural environment resulting from anthropogenic effects (technology applications) inducing an increase in concentration of natural radioactive substances accordingly increase the anthropogenic radiation exposure. Indoor air radon concentration in buildings for instance is one typical example of anthropogenic increase of concentration of natural radioactivity, primarily caused by the mining industry or by various materials processing activities, which may cause an increase in the average radiation dose to the population. Measurements so far show that indoor air concentration of radon exceeds a level of 200 Bq/m 3 in less than 2% of the residential buildings; the EUropean Commission therefore recommends to use this concentration value as a maximum value for new residential buildings. Higher concentrations are primarily measured in areas with relevant geological conditions and abundance of radon, or eg. in mining areas. (orig./CB) [de

  4. Reference dosimetry of proton pencil beams based on dose-area product: a proof of concept.

    Science.gov (United States)

    Gomà, Carles; Safai, Sairos; Vörös, Sándor

    2017-06-21

    This paper describes a novel approach to the reference dosimetry of proton pencil beams based on dose-area product ([Formula: see text]). It depicts the calibration of a large-diameter plane-parallel ionization chamber in terms of dose-area product in a 60 Co beam, the Monte Carlo calculation of beam quality correction factors-in terms of dose-area product-in proton beams, the Monte Carlo calculation of nuclear halo correction factors, and the experimental determination of [Formula: see text] of a single proton pencil beam. This new approach to reference dosimetry proves to be feasible, as it yields [Formula: see text] values in agreement with the standard and well-established approach of determining the absorbed dose to water at the centre of a broad homogeneous field generated by the superposition of regularly-spaced proton pencil beams.

  5. External doses from radioactive fallout. Dosimetry and levels

    International Nuclear Information System (INIS)

    Woehni, T.

    1995-01-01

    The design, manufacture and calibration of a TL-based dosemeter for measurement of low level external photon radiation are presented. The dosemeter is based on CaF 2 with 2 mm brass filter for energy compensation. It is able to resolve a 8% dose increase relative to natural background radiation. With this dosemeter external dose measurements were made in 6 villages in a heavily contaminated region in Russia (Chernobyl fallout), in order to assess external doses to the population. The results were analyzed in the light of additional existing information on radioactive deposition, social habits, decontamination measures and other influencing technical and physical factors. The observed dose values were lower than theoretical estimates of external doses based on published values for external dose levels relative to the level of contamination. 84 refs., 7 figs., 5 tabs

  6. External doses from radioactive fallout. Dosimetry and levels

    Energy Technology Data Exchange (ETDEWEB)

    Woehni, T

    1996-12-31

    The design, manufacture and calibration of a TL-based dosemeter for measurement of low level external photon radiation are presented. The dosemeter is based on CaF{sub 2} with 2 mm brass filter for energy compensation. It is able to resolve a 8% dose increase relative to natural background radiation. With this dosemeter external dose measurements were made in 6 villages in a heavily contaminated region in Russia (Chernobyl fallout), in order to assess external doses to the population. The results were analyzed in the light of additional existing information on radioactive deposition, social habits, decontamination measures and other influencing technical and physical factors. The observed dose values were lower than theoretical estimates of external doses based on published values for external dose levels relative to the level of contamination. 84 refs., 7 figs., 5 tabs.

  7. External doses from radioactive fallout. Dosimetry and levels

    Energy Technology Data Exchange (ETDEWEB)

    Woehni, T.

    1995-12-31

    The design, manufacture and calibration of a TL-based dosemeter for measurement of low level external photon radiation are presented. The dosemeter is based on CaF{sub 2} with 2 mm brass filter for energy compensation. It is able to resolve a 8% dose increase relative to natural background radiation. With this dosemeter external dose measurements were made in 6 villages in a heavily contaminated region in Russia (Chernobyl fallout), in order to assess external doses to the population. The results were analyzed in the light of additional existing information on radioactive deposition, social habits, decontamination measures and other influencing technical and physical factors. The observed dose values were lower than theoretical estimates of external doses based on published values for external dose levels relative to the level of contamination. 84 refs., 7 figs., 5 tabs.

  8. Studies on the establishment of maximum permissible exposure dose for reference Korean

    International Nuclear Information System (INIS)

    Kim, Y.J.; Lee, K.S.; Chun, K.C.; Kim, C.B.; Chung, K.H.; Kim, S.L.; Kim, M.J.

    1981-01-01

    In order to establish the Reference Korean and maximum permissible exposure dose of Reference Korean, for the first year a total of 9,758 males and 7,019 females were surveyed for the height, weight, a body surface area, and a total of 879 individuals of 180 households located in different 30 localities were analyzed for food consumption and a total of radioactive substances (β-ray) contained in food per capita per day. In this report the external and internal exposure dose were also estimated on the basis of data mostly published in other country as well as in Korea in part

  9. Effect of radiation dose level on the detectability of pulmonary nodules in chest tomosynthesis.

    Science.gov (United States)

    Asplund, Sara A; Johnsson, Åse A; Vikgren, Jenny; Svalkvist, Angelica; Flinck, Agneta; Boijsen, Marianne; Fisichella, Valeria A; Månsson, Lars Gunnar; Båth, Magnus

    2014-07-01

    To investigate the detectability of pulmonary nodules in chest tomosynthesis at reduced radiation dose levels. Eighty-six patients were included in the study and were examined with tomosynthesis and computed tomography (CT). Artificial noise was added to simulate that the tomosynthesis images were acquired at dose levels corresponding to 12, 32, and 70% of the default setting effective dose (0.12 mSv). Three observers (with >20, >20 and three years of experience) read the tomosynthesis cases for presence of nodules in a free-response receiver operating characteristics (FROC) study. CT served as reference. Differences between dose levels were calculated using the jack-knife alternative FROC (JAFROC) figure of merit (FOM). The JAFROC FOM was 0.45, 0.54, 0.55, and 0.54 for the 12, 32, 70, and 100% dose levels, respectively. The differences in FOM between the 12% dose level and the 32, 70, and 100% dose levels were 0.087 (p = 0.006), 0.099 (p = 0.003), and 0.093 (p = 0.004), respectively. Between higher dose levels, no significant differences were found. A substantial reduction from the default setting dose in chest tomosynthesis may be possible. In the present study, no statistically significant difference in detectability of pulmonary nodules was found when reducing the radiation dose to 32%. • A substantial radiation dose reduction in chest tomosynthesis may be possible. • Pulmonary nodule detectability remained unchanged at 32% of the effective dose. • Tomosynthesis might be performed at the dose of a lateral chest radiograph.

  10. SU-E-I-33: Establishment of CT Diagnostic Reference Levels in Province Nova Scotia

    Energy Technology Data Exchange (ETDEWEB)

    Tonkopi, E; Abdolell, M; Duffy, S [Dalhousie University and Queen Elizabeth II Health Sciences Centre, Halifax, NS (Canada)

    2015-06-15

    Purpose: To evaluate patient radiation dose from the most frequently performed CT examinations and to establish provincial diagnostic reference levels (DRLs) as a tool for protocol optimization. Methods: The study investigated the following CT examinations: head, chest, abdomen/pelvis, and chest/abdomen/pelvis (CAP). Dose data, volume CT dose index (CTDIvol) and dose-length product (DLP), were collected from 15 CT scanners installed during 2004–2014 in 11 hospital sites of Nova Scotia. All scanners had dose modulation options and multislice capability (16–128 detector rows). The sample for each protocol included 15 average size patients (70±20 kg). Provincial DRLs were calculated as the 75th percentile of patient dose distributions. The differences in dose between hospitals were evaluated with a single factor ANOVA statistical test. Generalized linear modeling was used to determine the factors associated with higher radiation dose. A sample of 36 abdominal studies performed on three different scanners was blinded and randomized for an assessment by an experienced radiologist who graded the imaging quality of anatomic structures. Results: Data for 900 patients were collected. The DRLs were proposed using CTDIvol (mGy) and DLP (mGy*cm) values for CT head (67 and 1049, respectively), chest (12 and 393), abdomen/pelvis (16 and 717), and CAP (14 and 1034). These DRLs were lower than the published national data except for the head CTDIvol. The differences between the means of the dose distributions from each scanner were statistically significant (p<0.05) for all examinations. A very weak correlation was found between the dose and the scanner age or the number of slices with Pearson’s correlation coefficients of 0.011–0.315. The blinded analysis of image quality demonstrated no clinically significant difference except for the noise category. Conclusion: Provincial DRLs were established for typical CT examinations. The variations in dose between the hospitals

  11. Data base of dose coefficients called ecrin-V1-internet reference handbook

    International Nuclear Information System (INIS)

    Perrin, M.L.

    2003-07-01

    The objective of this data base is to dispose on a only computer medium the values of radiation doses allowing to guarantee the tracing and the coherence of radiation doses received by man. These data are usable to evaluate the risks in the frame of studies or expertise. They include the doses coming from external irradiations, internal contamination by inhalation or ingestion and receive by workers or public. The definitions and reference values come from international publications (the list is given). (N.C.)

  12. Using Population Dose to Evaluate Community-level Health Initiatives.

    Science.gov (United States)

    Harner, Lisa T; Kuo, Elena S; Cheadle, Allen; Rauzon, Suzanne; Schwartz, Pamela M; Parnell, Barbara; Kelly, Cheryl; Solomon, Loel

    2018-05-01

    Successful community-level health initiatives require implementing an effective portfolio of strategies and understanding their impact on population health. These factors are complicated by the heterogeneity of overlapping multicomponent strategies and availability of population-level data that align with the initiatives. To address these complexities, the population dose methodology was developed for planning and evaluating multicomponent community initiatives. Building on the population dose methodology previously developed, this paper operationalizes dose estimates of one initiative targeting youth physical activity as part of the Kaiser Permanente Community Health Initiative, a multicomponent community-level obesity prevention initiative. The technical details needed to operationalize the population dose method are explained, and the use of population dose as an interim proxy for population-level survey data is introduced. The alignment of the estimated impact from strategy-level data analysis using the dose methodology and the data from the population-level survey suggest that dose is useful for conducting real-time evaluation of multiple heterogeneous strategies, and as a viable proxy for existing population-level surveys when robust strategy-level evaluation data are collected. This article is part of a supplement entitled Building Thriving Communities Through Comprehensive Community Health Initiatives, which is sponsored by Kaiser Permanente, Community Health. Copyright © 2018 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  13. Organ doses for reference pediatric and adolescent patients undergoing computed tomography estimated by Monte Carlo simulation

    International Nuclear Information System (INIS)

    Lee, Choonsik; Kim, Kwang Pyo; Long, Daniel J.; Bolch, Wesley E.

    2012-01-01

    Purpose: To establish an organ dose database for pediatric and adolescent reference individuals undergoing computed tomography (CT) examinations by using Monte Carlo simulation. The data will permit rapid estimates of organ and effective doses for patients of different age, gender, examination type, and CT scanner model. Methods: The Monte Carlo simulation model of a Siemens Sensation 16 CT scanner previously published was employed as a base CT scanner model. A set of absorbed doses for 33 organs/tissues normalized to the product of 100 mAs and CTDI vol (mGy/100 mAs mGy) was established by coupling the CT scanner model with age-dependent reference pediatric hybrid phantoms. A series of single axial scans from the top of head to the feet of the phantoms was performed at a slice thickness of 10 mm, and at tube potentials of 80, 100, and 120 kVp. Using the established CTDI vol - and 100 mAs-normalized dose matrix, organ doses for different pediatric phantoms undergoing head, chest, abdomen-pelvis, and chest-abdomen-pelvis (CAP) scans with the Siemens Sensation 16 scanner were estimated and analyzed. The results were then compared with the values obtained from three independent published methods: CT-Expo software, organ dose for abdominal CT scan derived empirically from patient abdominal circumference, and effective dose per dose-length product (DLP). Results: Organ and effective doses were calculated and normalized to 100 mAs and CTDI vol for different CT examinations. At the same technical setting, dose to the organs, which were entirely included in the CT beam coverage, were higher by from 40 to 80% for newborn phantoms compared to those of 15-year phantoms. An increase of tube potential from 80 to 120 kVp resulted in 2.5-2.9-fold greater brain dose for head scans. The results from this study were compared with three different published studies and/or techniques. First, organ doses were compared to those given by CT-Expo which revealed dose differences up to

  14. Transposition of the 97/43 EURATOM directive. Mission on procedures and standard levels of medical examinations using ionizing radiations. The radiological procedures: quality criteria and doses optimization; Transposition de la directive 97/43 Euratom. Mission sur les procedures et les niveaux de reference des examens medicaux utilisant les rayonnements ionisants. Les procedures radiologiques: criteres de qualite et optimisation des doses

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The objective of this report concerns the optimization of radiological practices, to avoid delivering unuseful doses while ensuring an image quality necessary to the obtaining of the desired diagnosis information. (N.C.)

  15. Proposed Oral Reference Dose (RfD) for Barium and Compounds (Final Report, 2004)

    Science.gov (United States)

    This document is the final report from the 2004 external peer review of the Proposed Oral Reference Dose (RfD) for Barium and Compounds, prepared by the U.S. Environmental Protection Agency (EPA), National Center for Environmental Assessment (NCEA), for the Integrated Risk...

  16. Bioequivalence of fixed-dose combination RIN®-150 to each reference drug in loose combination.

    Science.gov (United States)

    Wang, H F; Wang, R; O'Gorman, M; Crownover, P; Damle, B

    2015-03-01

    RIN(®)-150 is a fixed-dose combination (FDC) tablet containing rifampicin (RMP, 150 mg) and isoniazid (INH, 75 mg) developed for the treatment of tuberculosis. This study was conducted at a single center: the Pfizer Clinical Research Unit in Singapore. To demonstrate bioequivalence of each drug component between RIN-150 and individual products in a loose combination. This was a randomized, open-label, single-dose, two-way crossover study. Subjects received single doses of RIN-150 or two individual reference products under fasting conditions in a crossover fashion, with at least 7 days washout between doses. The primary measures for comparison were peak plasma concentration (Cmax) and the area under plasma concentration-time curve (AUC). Of 28 subjects enrolled, 26 completed the study. The adjusted geometric mean ratios of Cmax and AUClast between the FDC and single-drug references and 90% confidence intervals were respectively 91.63% (90%CI 83.13-101.01) and 95.45% (90%CI 92.07-98.94) for RMP, and 107.58% (90%CI 96.07-120.47) and 103.45% (90%CI 99.33-107.75) for INH. Both formulations were generally well tolerated in this study. The RIN-150 FDC tablet formulation is bioequivalent to the two single-drug references for RMP and INH at equivalent doses.

  17. Dose distribution in organs: patient-specific phantoms versus reference phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda, I.V.B., E-mail: isabelle.lacerda@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife (Brazil); Vieira, J.W. [Instituto Federal de Pernambuco (IFPE), Recife (Brazil); Oliveira, M.L.; Lima, F.R.A. [Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE/CNEN-PB), Recife (Brazil)

    2017-07-01

    Discrepancies between ICRP phantoms and real patients lead to disparities on patient-dose estimations. This paper aims to compare distribution of dose in organs of male/female specific-phantoms and ICRP reference phantoms. The absorbed dose estimation was performed using the EGSnrc Monte Carlo code and a parallel source algorithm. In this work were used a patient-specific phantom for a man (1.73m/70.3kg) and another for a woman (1.63m/60.3kg) and the male and female ICRP reference phantoms. The comparison of the absorbed dose from each phantom gender was performed using the relative error. The results were expressed in terms of conversion coefficients to brain, lungs, liver and kidneys. The greatest absolute relative error between the organs of the patient-specific phantom and the reference phantom was 22.92% in the liver and 62.84% in the kidneys, respectively for man and woman. There are errors that cannot be disregarded. This paper shows the need for a specific study for each patient or for the population of each country, since there are different body types, which affects the distribution of the organ doses. (author)

  18. Dose distribution in organs: patient-specific phantoms versus reference phantoms

    International Nuclear Information System (INIS)

    Lacerda, I.V.B.; Vieira, J.W.; Oliveira, M.L.; Lima, F.R.A.

    2017-01-01

    Discrepancies between ICRP phantoms and real patients lead to disparities on patient-dose estimations. This paper aims to compare distribution of dose in organs of male/female specific-phantoms and ICRP reference phantoms. The absorbed dose estimation was performed using the EGSnrc Monte Carlo code and a parallel source algorithm. In this work were used a patient-specific phantom for a man (1.73m/70.3kg) and another for a woman (1.63m/60.3kg) and the male and female ICRP reference phantoms. The comparison of the absorbed dose from each phantom gender was performed using the relative error. The results were expressed in terms of conversion coefficients to brain, lungs, liver and kidneys. The greatest absolute relative error between the organs of the patient-specific phantom and the reference phantom was 22.92% in the liver and 62.84% in the kidneys, respectively for man and woman. There are errors that cannot be disregarded. This paper shows the need for a specific study for each patient or for the population of each country, since there are different body types, which affects the distribution of the organ doses. (author)

  19. Background and anthropogenic radionuclide derived dose rates to freshwater ecosystem - Nuclear power plant cooling pond - Reference organisms

    International Nuclear Information System (INIS)

    Nedveckaite, T.; Filistovic, V.; Marciulioniene, D.; Prokoptchuk, N.; Plukiene, R.; Gudelis, A.; Remeikis, V.; Yankovich, T.; Beresford, N.-A.

    2011-01-01

    The radiological assessment of non-human biota to demonstrate protection is now accepted by a number of international and national bodies. Therefore, it is necessary to develop a scientific basis to assess and evaluate exposure of biota to ionizing radiation. Radionuclides from the Ignalina Nuclear Power Plant (Lithuania) were discharged into Lake Druksiai cooling pond. Additional radionuclide migration and recharge to this lake from a hypothetical near-surface, low-level radioactive waste disposal, to be situated 1.5 km from the lake, had been simulated using RESRAD-OFFSITE code. This paper uses ERICA Integrated Approach with associated tools and databases to compare the radiological dose to freshwater reference organisms. Based on these data, it can be concluded that background dose rates to non-human biota in Lake Druksiai far exceed those attributable to anthropogenic radionuclides. With respect the fishery and corresponding annual committed effective human dose as a result of this fish consumption Lake Druksiai continues to be a high-productivity water body with intensive angling and possible commercial fishing. - Highlights: → Dose rates to the reference organisms are lower than expected from the background radioactivity. → Pelagic fish part of adult human annual committed effective dose would be as small as a few μSv y -1 . → With respect the fishery Lake Druksiai continues to be a high-productivity water body.

  20. Factors affecting quality for beta dose rate measurements using ISO 6980 series I reference sources

    Energy Technology Data Exchange (ETDEWEB)

    Burns, R.E. Jr.; O`Brien, J.M. Jr. [Atlan-Tech, Rosewll, GA (United States)

    1993-12-31

    Atlan-Tech, Inc. has performed several calibrations of ISO 6980 Series 1 reference beta sources over the past two to three years. There were many problems encountered in attempting to compare the results of these calibrations with those from other laboratories, indicating the need for more standardization in the methodology employed for the measurement of the absorbed dose rate from ISO 6980 Series 1 reference beta sources. This document describes some of the problems encountered in attempting to intercompare results of beta dose-rate measurements. It proposes some solutions in an attempt to open a dialogue among facilities using reference beta standards for the purpose of promoting better measurement quality assurance through data intercomparison.

  1. Factors affecting quality for beta dose rate measurements using ISO 6980 series I reference sources

    International Nuclear Information System (INIS)

    Burns, R.E. Jr.; O'Brien, J.M. Jr.

    1993-01-01

    Atlan-Tech, Inc. has performed several calibrations of ISO 6980 Series 1 reference beta sources over the past two to three years. There were many problems encountered in attempting to compare the results of these calibrations with those from other laboratories, indicating the need for more standardization in the methodology employed for the measurement of the absorbed dose rate from ISO 6980 Series 1 reference beta sources. This document describes some of the problems encountered in attempting to intercompare results of beta dose-rate measurements. It proposes some solutions in an attempt to open a dialogue among facilities using reference beta standards for the purpose of promoting better measurement quality assurance through data intercomparison

  2. A New Dual-purpose Quality Control Dosimetry Protocol for Diagnostic Reference-level Determination in Computed Tomography.

    Science.gov (United States)

    Sohrabi, Mehdi; Parsi, Masoumeh; Sina, Sedigheh

    2018-05-17

    A diagnostic reference level is an advisory dose level set by a regulatory authority in a country as an efficient criterion for protection of patients from unwanted medical exposure. In computed tomography, the direct dose measurement and data collection methods are commonly applied for determination of diagnostic reference levels. Recently, a new quality-control-based dose survey method was proposed by the authors to simplify the diagnostic reference-level determination using a retrospective quality control database usually available at a regulatory authority in a country. In line with such a development, a prospective dual-purpose quality control dosimetry protocol is proposed for determination of diagnostic reference levels in a country, which can be simply applied by quality control service providers. This new proposed method was applied to five computed tomography scanners in Shiraz, Iran, and diagnostic reference levels for head, abdomen/pelvis, sinus, chest, and lumbar spine examinations were determined. The results were compared to those obtained by the data collection and quality-control-based dose survey methods, carried out in parallel in this study, and were found to agree well within approximately 6%. This is highly acceptable for quality-control-based methods according to International Atomic Energy Agency tolerance levels (±20%).

  3. An approach to local diagnostic reference levels (DRL's) in the context of national and international DRL's

    International Nuclear Information System (INIS)

    Rogers, A.T.

    2001-01-01

    In recent years there has been a greater focus on the management of patient doses. This effort has been driven by the realisation of both the increasing magnitude of patient doses and their variation both intra- and inter-nationally. Legislators and guidance-issuing bodies have developed the idea of 'Diagnostic Reference Levels' (DRL's). In particular, the European Union, in their Council Directive 97/43/Euratom, required Member States to develop DRL's. The UK Government, when consolidating this EU Directive into UK legislation, extended the concept of DRL's from a national to an employer level. However, the methodologies used for development of national and international DRL's do not translate to a local level and hence a new approach is required. This paper describes one particular approach made by a UK hospital to introduce 'Local DRL's' in such a manner as to aid the optimisation process. This approach utilises a dose index, based on the local patient population, which is monitored for trends. Any trend in patient dose triggers an investigation linked to the clinical audit system within the Clinical Radiology Department. It is the audit cycle that ensures a continuing move towards an optimised situation. Additional triggers may be employed such as large patient dose variations. (author)

  4. Local diagnostic reference levels at the Portuguese Institute of oncology francisco gentil of coimbra

    Energy Technology Data Exchange (ETDEWEB)

    Bras, S.; Sousa, M.C. de [Algarve Univ., LIP-Algarve, FCT (Portugal); Lopes, M.C. [IPOFG-CROC, S.A., Medical Physics Dept., Coimbra (Portugal)

    2006-07-01

    In the scope of medical radiological exposures and according to European recommendations and national legal requirements [14], the maximum responsible for an installation must assure the establishment of local dose levels for each type of radiological examination and also assure that they are available for the doctor who prescribes the examination. In the absence of national reference dose levels, the so called Local Diagnostic Reference Levels (L.D.R.L.) should be in agreement with the European Diagnostic Reference Levels published for the different types of medical exposures. The aim of this work was to establish a protocol of measurement for each type of more frequent examination, namely in conventional radiology, in CT and in mammography performed in our hospital. For each kind of examination the recommended dose descriptor was adopted and directly measured or derived from basic charge measurements. The patient sample corresponded in each case to at least a minimum of 10 standard-sized patients, as recommended, in order to obtain averages that constitute for each type of radiological examination the L.D.R.L. that could be compared with the European D.R.L.. The results obtained are in the large majority of the situations below the corresponding D.R.L.. Nevertheless we have identified some situations that deserve more attention.In conventional radiology all L.D.R.L. are below the reference levels. However we have detected some skull post anterior (skull P.A.) exposures where entrance skin doses exceeded the standard value. This may be due to equipment age problems but, as always, improvement of staff education will contribute to better practices and we hope that this work can contribute to this objective. In CT the L.D.R.L. that corresponds to single slice scan meet the standards whereas complete examinations described by dose length product (D.L.P.) values show a larger variation and also some situations where the reference level is exceeded. It is possible that

  5. Local diagnostic reference levels at the Portuguese Institute of oncology francisco gentil of coimbra

    International Nuclear Information System (INIS)

    Bras, S.; Sousa, M.C. de; Lopes, M.C.

    2006-01-01

    In the scope of medical radiological exposures and according to European recommendations and national legal requirements [14], the maximum responsible for an installation must assure the establishment of local dose levels for each type of radiological examination and also assure that they are available for the doctor who prescribes the examination. In the absence of national reference dose levels, the so called Local Diagnostic Reference Levels (L.D.R.L.) should be in agreement with the European Diagnostic Reference Levels published for the different types of medical exposures. The aim of this work was to establish a protocol of measurement for each type of more frequent examination, namely in conventional radiology, in CT and in mammography performed in our hospital. For each kind of examination the recommended dose descriptor was adopted and directly measured or derived from basic charge measurements. The patient sample corresponded in each case to at least a minimum of 10 standard-sized patients, as recommended, in order to obtain averages that constitute for each type of radiological examination the L.D.R.L. that could be compared with the European D.R.L.. The results obtained are in the large majority of the situations below the corresponding D.R.L.. Nevertheless we have identified some situations that deserve more attention.In conventional radiology all L.D.R.L. are below the reference levels. However we have detected some skull post anterior (skull P.A.) exposures where entrance skin doses exceeded the standard value. This may be due to equipment age problems but, as always, improvement of staff education will contribute to better practices and we hope that this work can contribute to this objective. In CT the L.D.R.L. that corresponds to single slice scan meet the standards whereas complete examinations described by dose length product (D.L.P.) values show a larger variation and also some situations where the reference level is exceeded. It is possible that

  6. Derived reference levels for prenatal exposure in a radiological emergency

    International Nuclear Information System (INIS)

    Nuccetelli, C.; Risica, S.; Rogani, A.

    2002-01-01

    After the Chernobyl accident many countries renewed their radiological emergency plans, also considering the possibility of over boundary accidents. This has been set out by the 96/29/Euratom Directive (Council Directive, 1996), which states that E ach Member State shall ensure that account is taken of the fact that radiological emergencies may occur in connection with practices on or outside its territory and affect it . Moreover, after September 11, 2001, the need to prepare emergency plans for possible terroristic attacks became evident and these plans are now being worked out in many countries for intervention in case of biological, chemical and/or radiological risk. In the event of radiological emergency, all decisions to be taken are based on possible doses to critical groups (European Commission, 1997), which are the population groups most at risk. These critical groups are, in most cases, infants or children, given that dose coefficients for these age groups are generally higher than for adults. However, a new ICRP Recommendation (ICRP, 2001) has recently been published that gives dose coefficients for embryo/foetus due to intake by the mother, by inhalation or ingestion, of 31 radionuclides. Also as a result of the revaluation in the last years of the possible health effects of prenatal exposure to ionising radiation (see e.g. the review in P. Fattibene et al., 1999), the consequences for the embryo/foetus of a possible radiological emergency connected to a nuclear plant and to possible dispersion of Depleted Uranium (DU) in the environment are analysed and discussed in this paper. For the former type of accident, Derived Intervention Levels (DILs) are calculated for prenatal exposure due to acute inhalation by the mother (female member of the public) and an assessment is performed of ingestion doses for the offspring resulting from consumption of foodstuffs by the mother of which 10% of the annual consumption is contaminated at the maximum levels

  7. Nordic Guidance Levels for Patient Doses in Diagnostic Radiology

    International Nuclear Information System (INIS)

    Saxebol, G.; Olerud, H.M.; Hjardemaal, O.; Leitz, W.; Servomaa, A.; Walderhaug, T.

    1998-01-01

    Within the framework of Nordic authoritative cooperation in radiation protection and nuclear safety, recommendations have been prepared dealing with dose constraints in diagnostic radiology. A working group with participants from all the Nordic countries has met and discussed possible implementations of the ICRP dose constraint for medical radiology. Dose constraints, expressed as guidance levels, were specified for six different radiological examinations, i.e. chest, pelvis, lumbar spine, urography, barium meal and enema in units of kerma-area product and entrance surface dose. The recommendations are described in report No 5 in the series 'Report on Nordic Radiation Protection Cooperation'. Examples of dose distributions and factors affecting the patient dose are described in the report. (author)

  8. 1997 N-Basin Administrative Control Level Dose Extension

    International Nuclear Information System (INIS)

    Nellesen, A.L.

    1997-04-01

    This document provides justification for extending the Administrative Control Level of 500 mrem per year to 1,000 mrem per year Total Effective Dose Equivalent for workers involved with N-Reactor Basin Deactivation in accordance with established procedures

  9. Natural dose level determination at Johor State with thermoluminescence dosimetry

    International Nuclear Information System (INIS)

    Ahmad Termizi Ramli; Yusof Jasman

    1995-01-01

    This paperwork presented the results of using thermoluminescence dosimetry (TLD) method in measuring background dose level, which is done at State of Johor, South Malaysia. The problems faced also discussed

  10. Evaluation of dose conversion coefficients for external exposure using Taiwanese reference man and woman

    International Nuclear Information System (INIS)

    Chang, S.J.; Hung, S.Y.; Liu, Y.L.; Jiang, S.H.; Wu, J.

    2015-01-01

    Reference man has been widely used for external and internal dose evaluation of radiation protection. The parameters of the mathematical model of organs suggested by the International Commission of Radiological Protection (ICRP) are adopted from the average data of Caucasians. However, the organ masses of Asians are significantly different from the data of Caucasians, leading to potentially dosimetric errors. In this study, a total of 40 volunteers whose heights and weights corresponded to the statistical average of Taiwanese adults were recruited. Magnetic resonance imaging was performed, and T2-weighted images were acquired. The Taiwanese reference man and woman were constructed according to the measured organ masses. The dose conversion coefficients (DCFs) for anterior-posterior (AP), posterior-anterior (PA), right lateral (RLAT) and left lateral (LLAT) irradiation geometries were simulated. For the Taiwanese reference man, the average differences of the DCFs compared with the results of ICRP-74 were 7.6, 5.1 and 11.1 % for 0.1, 1 and 10 MeV photons irradiated in the AP direction. The maximum difference reached 51.7 % for the testes irradiated by 10 MeV photons. The size of the trunk, the volume and the geometric position of organs can cause a significant impact on the DCFs for external exposure of radiation. The constructed Taiwanese reference man and woman can be used in radiation protection to increase the accuracy of dose evaluation for the Taiwanese population. (authors)

  11. Radiation safety concerns and diagnostic reference levels for computed tomography scanners in Tamil Nadu

    International Nuclear Information System (INIS)

    Livingstone, Roshan S.; Dinakaran, Paul M.

    2011-01-01

    Radiation safety in computed tomography (CT) scanners is of concern due its widespread use in the field of radiological imaging. This study intends to evaluate radiation doses imparted to patients undergoing thorax, abdomen and pelvic CT examinations and formulate regional diagnostic reference levels (DRL) in Tamil Nadu, South India. In-site CT dose measurement was performed in 127 CT scanners in Tamil Nadu for a period of 2 years as a part of the Atomic Energy Regulatory Board (AERB)-funded project. Out of the 127 CT scanners,13 were conventional; 53 single-slice helical scanners (SSHS); 44 multislice CT (MSCT) scanners; and 17 refurbished scanners. CT dose index (CTDI) was measured using a 32-cm polymethyl methacrylate (PMMA)-body phantom in each CT scanner. Dose length product (DLP) for different anatomical regions was generated using CTDI values. The regional DRLs for thorax, abdomen and pelvis examinations were 557, 521 and 294 mGy cm, respectively. The mean effective dose was estimated using the DLP values and was found to be 8.04, 6.69 and 4.79 mSv for thorax, abdomen and pelvic CT examinations, respectively. The establishment of DRLs in this study is the first step towards optimization of CT doses in the Indian context. (author)

  12. Development of a Reference Dose for Perchlorate: Current Issues and Status

    Science.gov (United States)

    Pleus, R. C.; Goodman, G.; Mattie, D. R.

    2000-01-01

    The perchlorate anion (ClO4) is typically manufactured as the ammonium salt. The most common use of ammonium perchlorate is in the aerospace program as a component of solid rocket fuel. The perchlorate anion is exceedingly stable under environmental conditions and has been found in ground and surface waters in CA, NV, UT, AZ, TX, AK, NY, MD, WV and FL. The National Center for Environmental Assessment (NCEA) of the U.S. Environmental Protection Agency (US EPA) is in the process of developing an oral reference dose (RfD) for perchlorate. An oral RfD is a body-weight-adjusted dose that can be consumed daily over an entire lifetime with the expectation of no adverse health effects. Once developed, the new RfD will be used by US EPA as the basis of a safe-drinking-water level (SDWL) guideline. US EPA and regional regulatory agencies will then jointly or separately propose clean-up action levels for ground and surface waters at contaminated sites. The toxicological database on CIO4- as of March 1997 was determined by an expert peer-review panel to be inadequate for the purpose of deriving an oral RfD. For example, little or no experimental data existed on the subchronic, reproductive, or developmental toxicity of perchlorate. To fill gaps in the toxicological database, eight animal studies were designed by a government-industry consortium that included US EPA and AFRL. These studies were performed in 1997-1998. It has been known for many years that in the thyroid, high doses of perchlorate block the function of iodide by competing for iodide binding sites. Perchlorate was used in the 1950s-60s as a treatment for Graves' disease (a hyperthyroid condition). Because of what was already known about the pharmacological mode of action of perchlorate, specific concerns addressed in the design of the recent animal studies included the potential for developmental toxicity, notably neurological development. Upon review of complete study reports from four of the studies and

  13. Absorbed Internal Dose Conversion Coefficients for Domestic Reference Animals and Plant

    Energy Technology Data Exchange (ETDEWEB)

    Keum, Dong Kwon; Jun, In; Lim, Kwang Muk; Choi, Yong Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-02-15

    This paper describes the methodology of calculating the internal dose conversion coefficient in order to assess the radiological impact on non-human species. This paper also presents the internal dose conversion coefficients of 25 radionuclides ({sup 3}H, {sup 7}Be, {sup 14}C, {sup 40}K, {sup 51}Cr, {sup 54}Mn, {sup 59}Fe, {sup 58}Co, {sup 60}Co, {sup 65}Zn, {sup 90}Sr, '9{sup 5}Zr, {sup 95}Nb, {sup 99}Tc, {sup 106}Ru, {sup 129}I, {sup 131}I, {sup 136}Cs, {sup 137}Cs, {sup 140}Ba, {sup 140}La, {sup 144}Ce, {sup 238}U, {sup 239}Pu, {sup 240}Pu) for domestic seven reference animals (roe deer, rat, frog, snake, Chinese minnow, bee, and earthworm) and one reference plant (pine tree). The uniform isotropic model was applied in order to calculate the internal dose conversion coefficients. The calculated internal dose conversion coefficient (muGyd{sup -1} per Bqkg{sup -1}) ranged from 10{sup -6} to 10{sup -2} according to the type of radionuclides and organisms studied. It turns out that the internal does conversion coefficient was higher for alpha radionuclides, such as {sup 238}U, {sup 239}Pu, and {sup 240}Pu, and for large organisms, such as roe deer and pine tree. The internal dose conversion coefficients of {sup 239}Pu, {sup 240}Pu, {sup 238}U, {sup 14}C, {sup 3}H and {sup 99}Tc were independent of the organism

  14. On detecting reference level of acrolein content in children's blood

    Directory of Open Access Journals (Sweden)

    T.S. Ulanova

    2017-03-01

    Full Text Available The article gives the results of complex chemical-analytical and clinical-laboratory research in course of which biological media of children living in Perm region were examined. To study impacts exerted by exogenous acrolein we examined 156 children in 2014–2016, aged 5–10, attending pre-school facilities and schools, and living in Perm region. As we conducted this research we detected average annual acrolein concentration in atmosphere on the examined territory; this concentration was equal to 0.000024 mg/m3, and it was 1.2 times higher than reference acrolein concentration in the air for chronic inhalation exposure. Average group acrolein concentration in children's blood was 1.2 times authentically higher (р3.96, p≤0.05. We used increased content of delta-aminolevulinic acid in urine as a limiting marker for effects occurring at chronic inhalation exposure to acrolein. Basing on the results of the performed examination we recommend concentration equal to 0.10 mgr/dm 3 as a reference level of acrolein content in blood at chronic inhalation exposure.

  15. Diagnostic reference levels in digital mammography: a systematic review

    International Nuclear Information System (INIS)

    Suleiman, Moayyad E.; Brennan, Patrick C.; McEntee, Mark F.

    2015-01-01

    This study aims to review the literature on existing diagnostic reference levels (DRLs) in digital mammography and methodologies for establishing them. To this end, a systematic search through Medline, Cinahl, Web of Science, Scopus and Google scholar was conducted using search terms extracted from three terms: DRLs, digital mammography and breast screen. The search resulted in 1539 articles of which 22 were included after a screening process. Relevant data from the included studies were summarised and analysed. Differences were found in the methods utilised to establish DRLs including test subjects types, protocols followed, conversion factors employed, breast compressed thicknesses and percentile values adopted. These differences complicate comparison of DRLs among countries; hence, an internationally accepted protocol would be valuable so that international comparisons can be made. (authors)

  16. Radioactivity reference levels in ceramics tiles as building materials for different countries

    International Nuclear Information System (INIS)

    Ortiz, Josefina; Ballesteros, Luisa; Serradell, Vicente

    2008-01-01

    Measurements campaigns of ceramic tiles and raw materials used in them, shows that natural radionuclides of uranium ( 238 U) and thorium ( 232 Th) series, together with the radioactive isotope of potassium ( 40 K ), are presents. Uranium series contain radium, which decays to radon ( 222 Rn), an inert gas that can be released from materials and inhaled by individuals. Limits of 226 Ra concentrations are established by different countries in order to control Radon levels (200 Bq.m -3 in European Union). Potassium -40 and others gamma emitters of 226 Ra and 232 Th descendent, can cause an external dose. Therefore, with the purpose that individual doses due to building materials doesn't exceed a certain level recommendations or regulations have been established. A maximum value of 1 mSv.y -1 is recommended in European Union. In practice an easy way to avoid ceramic tiles provide doses to individuals over the reference level is to introduce an index, depending on activities concentrations of 226 Ra, 232 Th and 40 K, defined so that the dose limits due, exclusively, to building materials, will never be exceeded. These limits and indexes present differences between countries. In this paper indexes are compared and differences are discussed. (author)

  17. Cosmic radiation doses at flight level altitudes of airliners

    International Nuclear Information System (INIS)

    Viragh, E.; Petr, I.

    1985-01-01

    Changes are discussed in flux density of cosmic radiation particles with time as are the origin of cosmic radiation, the level of cosmic radiation near the Earth's surface, and the determination of cosmic radiation doses in airliners. Doses and dose rates are given measured on different flight routes. In spite of the fact that the flight duration at an altitude of about 10 km makes for about 80% of the total flight time, the overall radiation burden of the crews at 1000 flight hours a year is roughly double that of the rest of the population. (J.C.)

  18. An Assessment of Cs-137, R-226 and Pa-239, 240 doses for aquatic and terrestrial reference organisms in Poland

    International Nuclear Information System (INIS)

    Krajewski, P.; Suplinska, M.; Rosiak, I.

    2004-01-01

    The doses assessment for aquatic and terrestrial reference organisms was performed, based on the methodology elaborated by U.S. Department of Energy. Four organism types and their corresponding dose limits were used, and the principal exposure pathways were considered for aquatic animal, riparian animal, terrestrial plant, and terrestrial animal organism types respectively. Terrestrial rodent (apodemus flavicollis), Baltic Sea fish (cod, sprat, herring, plaice) and crustaceans (Sanduria entomon and Mytilus edulis) were taken in to special consideration. In the first screening approach the annual doses from 137Cs and 239Pu (bomb-tests-fallout and Czarnobyl origin) and 226Ra (natural radionuclide) to biota were calculated at average, minimum and maximum concentrations of these radionuclides observed in soil, water, and sediment using the default bioaccumulation factors as well as lumped parameters values recommended by DOE Standard. The concentrations of 137Cs measured in the most contaminated region in Poland (Stare Olesno 380 Bqxkg-1 d.w.) and the concentrations of 226Ra for Southern regions of Poland with elevated levels of 226Ra in soil (100 B kg-1 d.w.) were taken in the dose assessment for terrestrial animals. The concentrations of 137Cs and 239Pu and 226Ra determined in see water and bottom sediments from two sub-areas (Gdansk Basin and Bornholm Basin) were used in the dose assessment for aquatic biota. In the second ''site specific'' approach the average empirically measured concentrations of radionuclides in animal tissues were used. At the first approach the total maximal annual doses for terrestrial plants were less then one percent of the recommended dose limits ( 3600 mGyxy-1 ) and items for seawater organisms did not exceed a 40% of this limit whereas the total maximal annual doses for terrestrial animal were close to the recommended dose limit (360 mGyxy-1). It prompted to start supplementary site-specific biota dose assessment through site

  19. Provincial practice: adopting the new reference levels for Radon

    International Nuclear Information System (INIS)

    Kennedy, Christine; Johnson, Darryl

    2008-01-01

    Full text: In June 2007 new reference levels for radon gas were announced from Health Canada. These new levels brought new attention to the issue of radon gas exposure in the Province of Newfoundland and Labrador. Research in radon gas exposure has a long history in the fluorspar mines of the Burin Peninsula, indeed, occupational data from the 1950 's and 60 's had been included in Darby et al. large scale occupational meta analyses. Radon was also implicated in a royal commission of occupational mining hazards in Newfoundland in 1968. Although, the occupational exposures of miners have been well documented, very little is known about population exposures in indoor spaces. Geological maps are currently being composed for national areas, but data for this province is not yet published. Information about mining tailings used in construction materials or as fill is very poor (unlike the data known for uranium mining tailings in Ontario and Manitoba). The challenges of estimating radon exposures for the province are myriad and these are explored here in this narrative study of how new information has to be generated, and then incorporated into new environmental public health policies for a population. The process by which new scientific information informs public health policy is described in this study of radon in Newfoundland and Labrador. Anticipated regulations for new buildings are discussed. (author)

  20. Preliminary Diagnostic Reference Levels of Adult CT at Aristide Ledantec National Hospital

    International Nuclear Information System (INIS)

    Diagne, M.; Gning, F.; Dieng, M. M.; Gueye, L.

    2015-01-01

    The number of Computed Tomography (CT) procedures performed in Senegal has widely increased as the CT is a powerful tool for the accurate and effective diagnosis. CT is a diagnostic imaging modality giving higher patient dose in comparison with other radiological procedures. The establishing of diagnostic reference levels (DRLs) is a way to optimize the radiation arising from CT procedures to as low as reasonable (ALARA) and to ensure good practice. Objective: The purpose of this study is to establish Local Diagnostic Reference Levels (LDRLs) at the University Hospital of Aristide LeDantec for CT examinations and to compare these values with the international Diagnostic Reference Levels (DRLs) to benchmark the local practice. Materials/Methods: This was a cross-sectional survey carried out in HALD between August 2014 and January 2015. Demographic data and acquisition parameters of 700 CT scan examinations performed on adult patients were collected from request forms and CT scan consoles. The values of CTDIw, CTDIvol and DLP were calculated using ImPACT (Imaging Performance and Assessment of Computed Tomography) software for Siemens Definition AS scanner of HALD. This was done by correlating the measurements from the National Radiological Protection Board (NRPB–R250) scanners with the effective dose calculated, using the CT–EXPO software. Data was analyzed using mean, range, 3rd quartile, as well as mean. Frequency tables and histogrammes were used to summarise the data. Results: The 3rd quartile doses in this study for head, chest, abdomen and pelvis were 89 mGy, 12 mGy, 16.5 mGy, and 15 mGy, respectively. These values were in good agreement with the values reported from the literature. (author)

  1. ICRU reference dose in an era of intensity-modulated radiation therapy clinical trials: Correlation with planning target volume mean dose and suitability for intensity-modulated radiation therapy dose prescription

    International Nuclear Information System (INIS)

    Yaparpalvi, Ravindra; Hong, Linda; Mah, Dennis; Shen Jin; Mutyala, Subhakar; Spierer, Marnee; Garg, Madhur; Guha, Chandan; Kalnicki, Shalom

    2008-01-01

    Background and Purpose: IMRT clinical trials lack dose prescription and specification standards similar to ICRU standards for two- and three-dimensional external beam planning. In this study, we analyzed dose distributions for patients whose treatment plans incorporated IMRT, and compared the dose determined at the ICRU reference point to the PTV doses determined from dose-volume histograms. Additionally, we evaluated if ICRU reference type single-point dose prescriptions are suitable for IMRT dose prescriptions. Materials and methods: For this study, IMRT plans of 117 patients treated at our institution were randomly selected and analyzed. The treatment plans were clinically applied to the following disease sites: abdominal (11), anal (10), brain (11), gynecological (15), head and neck (25), lung (15), male pelvis (10) and prostate (20). The ICRU reference point was located in each treatment plan following ICRU Report 50 guidelines. The reference point was placed in the central part of the PTV and at or near the isocenter. In each case, the dose was calculated and recorded to this point. For each patient - volume and dose (PTV, PTV mean, median and modal) information was extracted from the planned dose-volume histogram. Results: The ICRU reference dose vs PTV mean dose relationship in IMRT exhibited a weak positive association (Pearson correlation coefficient 0.63). In approximately 65% of the cases studied, dose at the ICRU reference point was greater than the corresponding PTV mean dose. The dose difference between ICRU reference and PTV mean doses was ≤2% in approximately 79% of the cases studied (average 1.21% (±1.55), range -4% to +4%). Paired t-test analyses showed that the ICRU reference doses and PTV median doses were statistically similar (p = 0.42). The magnitude of PTV did not influence the difference between ICRU reference and PTV mean doses. Conclusions: The general relationship between ICRU reference and PTV mean doses in IMRT is similar to that

  2. Discussion on Implementation of ICRP Recommendations Concerning Reference Levels and Optimisation

    International Nuclear Information System (INIS)

    2013-02-01

    International Commission on Radiological Protection (ICRP) Publication 103, 'The 2007 Recommendations of the International Commission on Radiological Protection', issued in 2007, defines emergency exposure situations as unexpected situations that may require the implementation of urgent protective actions and perhaps longer term protective actions. The ICRP continues to recommend optimisation and the use of reference levels to ensure an adequate degree of protection in regard to exposure to ionising radiation in emergency exposure situations. Reference levels represent the level of dose or risk above which it is judged to be inappropriate to plan to allow exposures to occur and for which protective actions should therefore be planned and optimised. National authorities are responsible for establishing reference levels. The Expert Group on the Implementation of New International Recommendations for Emergency Exposure Situations (EGIRES) performed a survey to analyse the established processes for optimisation of the protection strategy for emergency exposure situations and for practical implementation of the reference level concept in several member states of the Nuclear Energy Agency (NEA). The EGIRES collected information on several national optimisation strategy definitions, on optimisation of protection for different protective actions, and also on optimisation of urgent protective actions. In addition, national criteria for setting reference levels, their use, and relevant processes, including specific triggers and dosimetric quantifies in setting reference levels, are focus points that the EGIRES also evaluated. The analysis of national responses to this 2011 survey shows many differences in the interpretation and application of the established processes and suggests that most countries are still in the early stages of implementing these processes. Since 2011, national authorities have continued their study of the ICRP recommendations to incorporate them into

  3. A study to establish international diagnostic reference levels for paediatric computed tomography

    International Nuclear Information System (INIS)

    Vassileva, J.; Rehani, M.; Kostova-Lefterova, D.; Al-Naemi, H.M.; Al Suwaidi, J.S.; Arandjic, D.; Bashier, E.H.O.; Kodlulovich Renha, S.; El-Nachef, L.; Aguilar, J.G.; Gershan, V.; Gershkevitsh, E.; Gruppetta, E.; Hustuc, A.; Jauhari, A.; Hassan Kharita, Mohammad; Khelassi-Toutaoui, N.; Khosravi, H.R.; Khoury, H.; Kralik, I.; Mahere, S.; Mazuoliene, J.; Mora, P.; Muhogora, W.; Muthuvelu, P.; Nikodemova, D.; Novak, L.; Pallewatte, A.; Pekarovic, D.; Shaaban, M.; Shelly, E.; Stepanyan, K.; Thelsy, N.; Visrutaratna, P.; Zaman, A.

    2015-01-01

    The article reports results from the largest international dose survey in paediatric computed tomography (CT) in 32 countries and proposes international diagnostic reference levels (DRLs) in terms of computed tomography dose index (CTDI vol ) and dose length product (DLP). It also assesses whether mean or median values of individual facilities should be used. A total of 6115 individual patient data were recorded among four age groups: <1 y, >1-5 y, >5-10 y and >10-15 y. CTDI w , CTDI vol and DLP from the CT console were recorded in dedicated forms together with patient data and technical parameters. Statistical analysis was performed, and international DRLs were established at rounded 75. percentile values of distribution of median values from all CT facilities. The study presents evidence in favour of using median rather than mean of patient dose indices as the representative of typical local dose in a facility, and for establishing DRLs as third quartile of median values. International DRLs were established for paediatric CT examinations for routine head, chest and abdomen in the four age groups. DRLs for CTDI vol are similar to the reference values from other published reports, with some differences for chest and abdomen CT. Higher variations were observed between DLP values, based on a survey of whole multi-phase exams. It may be noted that other studies in literature were based on single phase only. DRLs reported in this article can be used in countries without sufficient medical physics support to identify non-optimised practice. Recommendations to improve the accuracy and importance of future surveys are provided. (authors)

  4. Radiation dose from solar flares at ground level

    International Nuclear Information System (INIS)

    O'Brien, K.

    1979-01-01

    Wdowczyk and Wolfendale (Nature, 268, 510, 1977) concluded that a very large solar flare producing exposure of 10 4 rad at ground level (lethal to almost any organism) has a possible frequency of once per 10 5 -10 8 yr. In the work reported similar results were obtained using a more elaborate model. Flares occuring from February 1956 to August 1972 were analyzed. The flare size distribution above the earth's atmosphere, and neutron flux, dose and dose equivalent at ground level at the latitude of Deep River, Canada, were calculated. The probable frequency of flares delivering various doses are given. Doses larger than 100 rad which have significant somatic effects on man and other animals may be delivered once in 10 6 years. The probability of 10 4 rad was found to be 10 -8 /yr. These calculations apply only to high geomagnetic latitudes. Field reversals during which the geomagnetic field is much weaker than current values total about 10% of the past 4 million years. This suggests that a very large flare delivering a large dose worldwide at ground level cannot be ruled out. (author)

  5. Adaptive Reference Levels in a Level-Crossing Analog-to-Digital Converter

    Directory of Open Access Journals (Sweden)

    Andrew C. Singer

    2008-11-01

    Full Text Available Level-crossing analog-to-digital converters (LC ADCs have been considered in the literature and have been shown to efficiently sample certain classes of signals. One important aspect of their implementation is the placement of reference levels in the converter. The levels need to be appropriately located within the input dynamic range, in order to obtain samples efficiently. In this paper, we study optimization of the performance of such an LC ADC by providing several sequential algorithms that adaptively update the ADC reference levels. The accompanying performance analysis and simulation results show that as the signal length grows, the performance of the sequential algorithms asymptotically approaches that of the best choice that could only have been chosen in hindsight within a family of possible schemes.

  6. Exhaled nitric oxide levels in asthma: Personal best versus reference values.

    Science.gov (United States)

    Smith, Andrew D; Cowan, Jan O; Taylor, D Robin

    2009-10-01

    Factors affecting the fraction of nitric oxide in exhaled air (FE(NO)) are multiple. Interpreting values when assessing airways disease may be problematic. Clinically optimum levels have not been defined. We aimed to establish the relationship between predicted values for FE(NO) obtained from equations by Olin et al, Travers et al, and Dressel et al, and normalized levels after oral prednisone. We also compared postprednisone FE(NO) levels with those obtained during optimized treatment with inhaled fluticasone. Data were obtained before and after a trial of oral prednisone (30mg/d for 14 days), and also from a previously published study in which patients had their dose of inhaled corticosteroid adjusted using either FE(NO) or symptoms/lung function to optimize treatment. Seventy-three patients completed the study. The geometric mean FE(NO) after prednisone (17.7 parts per billion [ppb]; 95% CI, 15.5-20.2) was significantly lower than mean FE(NO) at the optimized fluticasone dose (20.2 ppb; 95% CI, 17.1-23.8; P=.04) and at loss of control (27.6 ppb; 95% CI, 22.8-33.4; P values of Olin et al (16.8 ppb, 95% CI, 16.0-17.5; P=.44), but were significantly lower than values of Travers et al (predicted, 21.5 ppb; 95% CI, 20.9-22.2; P=.005) and Dressel et al (predicted, 27.8 ppb; 95% CI, 26.7-28.9; P values from the reference equation by Olin et al. However, at optimized doses of inhaled corticosteroid, although FE(NO) levels were higher than predicted, asthma was well controlled. Targeting FE(NO) on reference values is not justified.

  7. 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)

  8. Calculation of local skin doses with ICRP adult mesh-type reference computational phantoms

    Science.gov (United States)

    Yeom, Yeon Soo; Han, Haegin; Choi, Chansoo; Nguyen, Thang Tat; Lee, Hanjin; Shin, Bangho; Kim, Chan Hyeong; Han, Min Cheol

    2018-01-01

    Recently, Task Group 103 of the International Commission on Radiological Protection (ICRP) developed new mesh-type reference computational phantoms (MRCPs) for adult males and females in order to address the limitations of the current voxel-type reference phantoms described in ICRP Publication 110 due to their limited voxel resolutions and the nature of the voxel geometry. One of the substantial advantages of the MRCPs over the ICRP-110 reference phantoms is the inclusion of a 50-μm-thick radiosensitive skin basal-cell layer; however, a methodology for calculating the local skin dose (LSD), i.e., the maximum dose to the basal layer averaged over a 1-cm2 area, has yet to be developed. In the present study, a dedicated program for the LSD calculation with the MRCPs was developed based on the mean shift algorithm and the Geant4 Monte Carlo code. The developed program was used to calculate local skin dose coefficients (LSDCs) for electrons and alpha particles, which were then compared with the values given in ICRP Publication 116 that were produced with a simple tissue-equivalent cube model. The results of the present study show that the LSDCs of the MRCPs are generally in good agreement with the ICRP-116 values for alpha particles, but for electrons, significant differences are found at energies higher than 0.15 MeV. The LSDCs of the MRCPs are greater than the ICRP-116 values by as much as 2.7 times at 10 MeV, which is due mainly to the different curvature between realistic MRCPs ( i.e., curved) and the simple cube model ( i.e., flat).

  9. 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)

  10. A review of data on the effects of low and low dose-rate radiation with special reference to the dose limit problem

    International Nuclear Information System (INIS)

    Matsudaira, Hiromichi

    1977-01-01

    This is a review of data pertaining to detection and quantification of the effects after exposure to low LET radiations delivered at low and low dose-rate, i.e., at a level of maximum permissible dose for the radiation workers, on experimental materials ranging from plant to rodents and on some human populations. Irradiation at a dose of a few rad is reported to induce mutation or malignant transformation in some selected model systems, with a linear dose-effect relationship. Moreover, the incidence of the chromosome aberrations in spermatocytes is reported to be elevated in the scorpiones (Tityus bahiensis) collected in a region of high natural background radiations (several rem/year). An increase in the incidence of childhood malignancies is reported among children exposed in utero to diagnostic X-rays. Appreciable increase in the incidence of genetic diseases due possibly to chromosome aberrations is also reported among population living in a region of high natural background radiations. Points are raised and discussed as to the interpretation and particularly application of these data to the estimation of somatic and genetic risks of human population from man-made radiations. Recent attempts of risk-benefit analysis with populations subjected to mass X-ray examination of the chest and stomac are referred to. Since we are unaware of the actual injuries due to the exposure even at the level of radiation workers (5 rem/year), it is out of the capacity of a biologist to afford the basis for the decision of limiting the exposure of general population due to the light water reactor operation to 5 mrem/year. (auth.)

  11. Operator dependency of the radiation exposure in cardiac interventions: feasibility of ultra low dose levels

    International Nuclear Information System (INIS)

    Emre Ozpelit, Mehmet; Ercan, Ertugrul; Pekel, Nihat; Tengiz, Istemihan; Yilmaz, Akar; Ozpelit, Ebru; Ozyurtlu, Ferhat

    2017-01-01

    Introduction: Mean radiation exposure in invasive cardiology varies greatly between different centres and interventionists. The International Commission on Radiological Protection and the EURATOM Council stipulate that, despite reference values, 'All medical exposure for radiodiagnostic purposes shall be kept as low as reasonably achievable' (ALARA). The purpose of this study is to establish the effects of the routine application of ALARA principles and to determine operator and procedure impact on radiation exposure in interventional cardiology. Materials and methods: A total of 240 consecutive cardiac interventional procedures were analysed. Five operators performed the procedures, two of whom were working in accordance with ALARA principles (Group 1 operators) with the remaining three working in a standard manner (Group 2 operators). Radiation exposure levels of these two groups were compared. Results: Total fluoroscopy time and the number of radiographic runs were similar between groups. However, dose area product and cumulative dose were significantly lower in Group 1 when compared with Group 2. Radiation levels of Group 1 were far below even the reference levels in the literature, thus representing an ultra-low-dose radiation exposure in interventional cardiology. Conclusion: By use of simple radiation reducing techniques, ultra-low-dose radiation exposure is feasible in interventional cardiology. Achievability of such levels depends greatly on operator awareness, desire, knowledge and experience of radiation protection. (authors)

  12. Dose response curves for effects of low-level radiation

    International Nuclear Information System (INIS)

    Myers, D.K.

    1980-01-01

    The linear dose-response model used by international committees to assess the genetic and carcinogenic hazards of low-level radiation appears to be the most reasonable interpretation of the available scientific data that are relevant to this topic. There are, of course, reasons to believe that this model may overestimate radiation hazards in certain instances, a fact acknowledged in recent reports of these committees. The linear model is now also being utilized to estimate the potential carcinogenic hazards of other agents such as asbestos and polycyclic aromatic hydrocarbons. This model implies that there is no safe dose for any of these agents and that potential health hazards will increase in direct proportion to total accumulated dose. The practical implication is the recommendation that all exposures should be kept 'as low as reasonably achievable, economic and social factors being taken into account'. (auth)

  13. PLUTONIUM/HIGH-LEVEL VITRIFIED WASTE BDBE DOSE CALCULATION

    Energy Technology Data Exchange (ETDEWEB)

    J.A. Ziegler

    2000-11-20

    The purpose of this calculation is to provide a dose consequence analysis of high-level waste (HLW) consisting of plutonium immobilized in vitrified HLW to be handled at the proposed Monitored Geologic Repository at Yucca Mountain for a beyond design basis event (BDBE) under expected conditions using best estimate values for each calculation parameter. In addition to the dose calculation, a plutonium respirable particle size for dose calculation use is derived. The current concept for this waste form is plutonium disks enclosed in cans immobilized in canisters of vitrified HLW (i.e., glass). The plutonium inventory at risk used for this calculation is selected from Plutonium Immobilization Project Input for Yucca Mountain Total Systems Performance Assessment (Shaw 1999). The BDBE examined in this calculation is a nonmechanistic initiating event and the sequence of events that follow to cause a radiological release. This analysis will provide the radiological releases and dose consequences for a postulated BDBE. Results may be considered in other analyses to determine or modify the safety classification and quality assurance level of repository structures, systems, and components. This calculation uses best available technical information because the BDBE frequency is very low (i.e., less than 1.0E-6 events/year) and is not required for License Application for the Monitored Geologic Repository. The results of this calculation will not be used as part of a licensing or design basis.

  14. Internal and external dose conversion coefficient for domestic reference animals and plant

    Energy Technology Data Exchange (ETDEWEB)

    Keum, Dong Kwon; Jun, In; Lim, Kwang Muk; Park, Du Won; Choi, Young Ho

    2009-07-15

    This report presents the internal and external dose conversion coefficients for domestic reference animals and plant, which are essential to assess the radiological impact of an environmental radiation on non-human species. To calculate the dose conversion coefficients, a uniform isotropic model and a Monte Carlo method for a photon transport simulation in environmental media with different densities have been applied for aquatic and terrestrial animals, respectively. In the modeling all the target animals are defined as a simple 3D elliptical shape. To specify the external radiation source it is assumed that aquatic animals are fully immersed in infinite and uniformly contaminated water, and the on-soil animals are living on the surface of a horizontally infinite soil source, and the in-soil organisms are living at the center of a horizontally infinite and uniformly contaminated soil to a depth of 50cm. A set of internal and external dose conversion coefficients for 8 Korean reference animals and plant (rat, roe-deer, frog, snake, Chinese minnow, bee, earthworm, and pine tree) are presented for 25 radionuclides ({sup 3}H, {sup 7}Be, {sup 14}C, {sup 40}K, {sup 51}Cr, {sup 54}Mn, {sup 59}Fe, {sup 58}Co, {sup 60}Co, {sup 65}Zn, {sup 90}Sr, {sup 95}Zr, {sup 95}Nb, {sup 99}Tc, {sup 106}Ru, {sup 129}I, {sup 131}I, {sup 136}Cs, {sup 137}Cs, {sup 140}Ba, {sup 140}La, {sup 144}Ce, {sup 238}U, {sup 239}Pu, and {sup 240}Pu)

  15. Determination of a site-specific reference dose for methylmercury for fish-eating populations.

    Science.gov (United States)

    Shipp, A M; Gentry, P R; Lawrence, G; Van Landingham, C; Covington, T; Clewell, H J; Gribben, K; Crump, K

    2000-11-01

    Environmental risk-management decisions in the U.S. involving potential exposures to methylmercury currently use a reference dose (RfD) developed by the U.S. Environmental Protection Agency (USEPA). This RfD is based on retrospective studies of an acute poisoning incident in Iraq in which grain contaminated with a methylmercury fungicide was inadvertently used in the baking of bread. The exposures, which were relatively high but lasted only a few months, were associated with neurological effects in both adults (primarily paresthesia) and infants (late walking, late talking, etc.). It is generally believed that the developing fetus represents a particularly sensitive subpopulation for the neurological effects of methylmercury. The USEPA derived an RfD of 0.1 microg/kg/day based on benchmark dose (BMD) modeling of the combined neurological endpoints reported for children exposed in utero. This RfD included an uncertainty factor of 10 to consider human pharmacokinetic variability and database limitations (lack of data on multigeneration effects or possible long-term sequelae of perinatal exposure). Alcoa signed an Administrative Order of Consent for the conduct of a remedial investigation/feasibility study (RI/FS) at their Point Comfort Operations and the adjacent Lavaca Bay in Texas to address the effects of historical discharges of mercury-containing wastewater. In cooperation with the Texas Natural Resource Conservation Commission and USEPA Region VI, Alcoa conducted a baseline risk assessment to assess potential risk to human health and the environment. As a part of this assessment. Alcoa pursued the development of a site-specific RfD for methylmercury to specifically address the potential human health effects associated with the ingestion of contaminated finfish and shellfish from Lavaca Bay. Application of the published USEPA RfD to this site is problematic; while the study underlying the RfD represented acute exposure to relatively high concentrations of

  16. Fluoroscopy-guided insertion of nasojejunal tubes in children - setting local diagnostic reference levels

    International Nuclear Information System (INIS)

    Vitta, Lavanya; Raghavan, Ashok; Sprigg, Alan; Morrell, Rachel

    2009-01-01

    Little is known about the radiation burden from fluoroscopy-guided insertions of nasojejunal tubes (NJTs) in children. There are no recommended or published standards of diagnostic reference levels (DRLs) available. To establish reference dose area product (DAP) levels for the fluoroscopy-guided insertion of nasojejunal tubes as a basis for setting DRLs for children. In addition, we wanted to assess our local practice and determine the success and complication rates associated with this procedure. Children who had NJT insertion procedures were identified retrospectively from the fluoroscopy database. The age of the child at the time of the procedure, DAP, screening time, outcome of the procedure, and any complications were recorded for each procedure. As the radiation dose depends on the size of the child, the children were assigned to three different age groups. The sample size, mean, median and third-quartile DAPs were calculated for each group. The third-quartile values were used to establish the DRLs. Of 186 procedures performed, 172 were successful on the first attempt. These were performed in a total of 43 children with 60% having multiple insertions over time. The third-quartile DAPs were as follows for each age group: 0-12 months, 2.6 cGy cm 2 ; 1-7 years, 2.45 cGy cm 2 ; >8 years, 14.6 cGy cm 2 . High DAP readings were obtained in the 0-12 months (n = 4) and >8 years (n = 2) age groups. No immediate complications were recorded. Fluoroscopy-guided insertion of NJTs is a highly successful procedure in a selected population of children and is associated with a low complication rate. The radiation dose per procedure is relatively low. (orig.)

  17. Eye lens dosimetry in interventional cardiology: Results of staff dose measurements and link to patient dose levels

    International Nuclear Information System (INIS)

    Antic, V.; Ciraj-Bjelac, O.; Rehani, M.; Aleksandric, S.; Arandjic, D.; Ostojic, M.

    2013-01-01

    Workers involved in interventional cardiology procedures receive high eye lens dose if protection is not used. Currently, there is no suitable method for routine use for the measurement of eye dose. Since most angiography machines are equipped with suitable patient dosemeters, deriving factors linking staff eye doses to the patient doses can be helpful. In this study the patient kerma-area product, cumulative dose at an interventional reference point and eye dose in terms of Hp(3) of the cardiologists, nurses and radiographers for interventional cardiology procedures have been measured. Correlations between the patient dose and the staff eye dose were obtained. The mean eye dose was 121 mSv for the first operator, 33 mSv for the second operator/nurse and 12 mSv for radiographer. Normalised eye lens doses per unit kerma-area product were 0.94 mSv Gy -1 cm -2 for the first operator, 0.33 mSv Gy -1 cm -2 for the second operator/nurse and 0.16 mSv Gy -1 cm -2 for radiographers. Statistical analysis indicated that there is a weak but significant (p < 0.01) correlation between the eye dose and the kerma-area product for all three staff categories. These values are based on a local practice and may provide useful reference for other studies for validation and for wider utilisation in assessing the eye dose using patient dose values. (authors)

  18. Impact on Dose Coefficients Calculated with ICRP Adult Mesh-type Reference Computational Phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Yeom, Yeon Soo; Nguyen, Thang Tat; Choi, Chan Soo; Lee, Han Jin; Han, Hae Gin; Han, Min Cheol; Shin, Bang Ho; Kim, Chan Hyeong [Dept. of Nuclear Engineering, Hanyang University, Seoul (Korea, Republic of)

    2017-04-15

    In 2016, the International Commission on Radiological Protection (ICRP) formulated a new Task Group (TG) (i.e., TG 103) within Committee 2. The ultimate aim of the TG 103 is to develop the mesh-type reference computational phantoms (MRCPs) that can address dosimetric limitations of the currently used voxel-type reference computational phantoms (VRCPs) due to their limited voxel resolutions. The objective of the present study is to investigate dosimetric impact of the adult MRCPs by comparing dose coefficients (DCs) calculated with the MRCPs for some external and internal exposure cases and the reference DCs in ICRP Publications 116 and 133 that were produced with the adult VRCPs. In the present study, the DCs calculated with the adult MRCPs for some exposure cases were compared with the values in ICRP Publications 116 and 133. This comparison shows that in general the MRCPs provide very similar DCs for uncharged particles, but for charged particles provide significantly different DCs due to the improvement of the MRCPs.

  19. Optimisation of radioprotection of patients in nuclear medicine: assessment of doses for the new ICRP's reference voxelized phantoms

    International Nuclear Information System (INIS)

    Hadid, L.; Blanchardon, E.; Desbree, A.; Makovicka, L.; Zankl, M.

    2010-01-01

    As the ICPR (International Commission on Radiological Protection) decided to adopt voxelized phantoms to emulate a reference adult, the authors report the validation of calculations of the SFAs (specific absorbed fractions) for the new ICPR's reference phantoms. After a presentation of these phantoms, the authors briefly present the OEDIPE software which is used to compute the SAFs and notably the absorbed doses. They discuss the results obtained for the SAFs (for photons and for electrons) and for the doses

  20. Natural external radiation level and population dose in Hunan province

    International Nuclear Information System (INIS)

    1985-01-01

    A survey of the natural external radiation level in Hunan Province is reported. The measurements were performed with FD-71 scintillation radiometers. On the basis of measurements at about 1,600 locations, the contribution from cosmic radiation is found to be 3.0 x 10 -8 Gy.h -1 , and the average absorbed dose rates in air from terrestrial γ-radiation for outdoors, indoors and roads are determined to be 9.2, 13.1 and 9.0 x 10 -8 Gy.h -1 , respectively. The γ-radiation indoors is markedly higher than that outdoors by a factor of 1.42. The lowest γ-radiation level is found in the sedimentary plain around Donting Lake, while the highest absorbed dose rates in air from terrestrial radiation are observed in some areas with exposed granites. The indoor γ-radiation in brick houses is markedly higher than that in wooden houses. Tarred roads have evidently lower radiation level than sand-gravel roads or concrete roads. The annual effective dose equivalents to the population from cosmic and terrestrial sources are 0.256 and 0.756 mSv, respectively, with a total value of 1.012 mSv

  1. A reference dosimetric system for dose interval of radiotherapy based on alanine/RPE; Um sistema dosimetrico de referencia para o intervalo de doses da radioterapia baseado na alanina/RPE

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues Junior, Orlando; Galante, Ocimar L.; Campos, Leticia L. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: rodrijr@net.ipen.br

    2001-07-01

    This work describes the development of a reference dosimetric system based on alanine/EPR for radiotherapy dose levels. Currently the IPEN is concluding a similar system for the dose range used for irradiation of products, 10-10{sup 5} Gy. The objective of this work is to present the efforts towards to improve the measure accuracy for doses in the range between 1-10 Gy. This system could be used as reference by radiotherapy services, as much in the quality control of the equipment, as for routine accompaniment of more complex handling where the total doses can reach some grays. The system uses alanine as detector and electronic paramagnetic resonance - EPR as measure technique. To reach accuracy better than 5% mathematical studies on the best optimization of the EPR spectrometer parameters and methods for the handling of the EPR sign are discussed. (author)

  2. Analysis of the personal doses lower than the reporting level

    International Nuclear Information System (INIS)

    Askounis, P.; Papadomarkaki, E.; Kirgiakou, H.; Dimitropoulou, F.; Carinou, E.; Maltezos, A.; Kamenopoulou, V.

    2008-01-01

    The personnel dosimetry department of Greek Atomic Energy Commission (GAEC) is the only laboratory in the country that assures the individual monitoring of more than 10,500 workers with whole body dosemeters and 100 workers with extremity dosemeters at 1300 establishments. Every year a statistical analysis of the results is performed that provides data for epidemiological studies and assists the evaluation of the radiation protection system of the country. The aim of this study is to perform an analysis of the doses that are lower than the reporting level. The vast majority (92%) of the evaluated H p (10) doses has been reported and recorded as zero. The mean H p (10) (of the non-reported doses) per dosemeter and per monitoring period has been calculated for every geographical department of Greece. The results were compared with the ones produced by the external gamma rate measurements performed by GAEC's telemetric network. The conclusion that can be drawn is that the part of the TL signal of the personal dosemeters is due to the natural background radiation and this can affect the evaluation of the low doses

  3. Dose inhomogeneities at various levels of biological organization

    International Nuclear Information System (INIS)

    Bond, V.P.

    1988-01-01

    Dose inhomogeneities in both tumor and normal tissue, inherent to the application of boron neutron capture therapy (BNCT), can be the result not only of ununiform distribution of 10 B at various levels of biological organization, but also of the distribution of the thermal neutrons and of the energy depositions from more energetic neutrons and other radiations comprising the externally-applied beams. The severity of the problems resulting from such inhomogeneities, and approaches to evaluating them, are illustrated by three examples, at the macro, micro and intermediate levels

  4. Towards the definition of Institutional diagnostic reference levels in paediatric interventional cardiology procedures in Greece.

    Science.gov (United States)

    Kottou, S; Kollaros, N; Plemmenos, C; Mastorakou, I; Apostolopoulou, S C; Tsapaki, V

    2018-02-01

    This study aimed to evaluate paediatric radiation doses in a dedicated cardiology hospital, with the objective of characterising patterns in dose variation. The ultimate purpose was to define Local (Institutional) Diagnostic Reference Levels (LDRLs) for different types of paediatric cardiac interventional procedures (IC), according to patient age. From a total of 710 cases performed during three consecutive years, by operators with more than 15 years of experience, the age was noted in only 477 IC procedures. The median values obtained for Fluoroscopy Time (FT), Number of Frames (N) and Kerma Area Product (P KA ) by age range were 5.8 min, 1322 and 2.0 Gy.cm 2 for definition of LDRLs presents challenges mainly due to the multiple clinical and technical factors affecting the outcome. On the other hand the lack of paediatric IC DRLs makes the identification of good practices more difficult. A consensus is needed on IC procedures nomenclature and grouping in order to allow a common assessment and comparison of doses. Copyright © 2018 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  5. Alternatives to dose, quality factor and dose equivalent for low level irradiation

    International Nuclear Information System (INIS)

    Sondhaus, C.A.; Bond, V.P.; Feinendegen, L.E.

    1988-01-01

    Randomly occurring energy deposition events produced by low levels of ionizing radiation interacting with tissue deliver variable amounts of energy to the sensitive target volumes within a small fraction of the cell population. A model is described in which an experimentally derived function relating event size to cell response probability operates mathematically on the microdosimetric event size distribution characterizing a given irradiation and thus determines the total fractional number of responding cells; this fraction measures the effectiveness of the given radiation. Normalizing to equal numbers of events produced by different radiations and applying this cell response or hit size effectiveness function (HSEF) should define radiation quality, or relative effectiveness, on a more nearly absolute basis than do the absorbed dose and dose evaluation, which are confounded when applied to low level irradiations. Examples using both calculation and experimental data are presented. 15 refs., 18 figs

  6. Ambient radioactivity levels and radiation doses. Annual report 2011

    International Nuclear Information System (INIS)

    Bernhard-Stroel, Claudia; Hachenburger, Claudia; Trugenberger-Schnabel, Angela; Peter, Josef

    2013-07-01

    The annual report 2011 on ambient radioactivity levels and radiation doses covers the following issues: Part A: Natural environmental radioactivity, artificial radioactivity in the environment, occupational radiation exposure, radiation exposure from medical applications, the handling of radioactive materials and sources of ionizing radiation, non-ionizing radiation. Part B; Current data and their evaluation: Natural environmental radioactivity, artificial radioactivity in the environment, occupational radiation exposure, radiation exposure from medical applications, the handling of radioactive materials and sources of ionizing radiation, non-ionizing radiation. The Appendix includes Explanations of terms, radiation doses and related units, external and internal radiation exposure, stochastic and deterministic radiation effects, genetic radiation effects, induction of malignant neoplasm, risk assessment, physical units and glossary, laws, ordinances, guidelines, recommendations and other regulations concerning radiation protection, list of selected radionuclides.

  7. Dosimetric methodology and reference system for diagnostic level X radiation

    International Nuclear Information System (INIS)

    Potiens, Maria da Penha Albuquerque

    1999-01-01

    Several methodologies for the calibration of diagnostic radiology instruments were developed and established at the Calibration Laboratory of IPEN. These established radiation qualities are recommended by international standards. The methods may be used in the calibration procedures of survey meters used in radiation protection measurements (scattered radiation), instruments used in direct beams (attenuated and non attenuated beams) and quality control instruments. A reference system was proposed using two identical ionization chambers developed at IPEN. They differ only by the collecting electrode material, one of aluminium and the other of graphite. The different energetic dependence of the chamber's response provided a ratio related to the tube potential. The variation of only 0.28%, from 14.3 to 111 keV, on the energetic dependence of the graphite electrode chamber, provided the possibility of air kerma rate determination in the studied radiation beams. (author)

  8. Development of a Reference System for the determination of the personal dose equivalent and the constancy of X- Ray beams

    International Nuclear Information System (INIS)

    Vivolo, Vitor

    2006-01-01

    A reference system for the determination of the personal dose equivalent, Hp (10), and a quality control program of X-ray equipment used In radioprotection require the periodic verification of the X-ray beams constancy. In this work, two parallel-plate ionization chambers were developed with inner electrodes of different materials, and inserted into PMMA slab phantoms. One ionization chamber was developed with inner carbon electrodes and the other with inner aluminium electrodes. The two ionization chambers can be used as a Tandem system. The different energy response of the two ionization chambers allowed the development of the Tandem system that is very useful for the checking of the constancy of beam qualities. Standard intermediary energy X-ray beams (from 48 keV to 118 keV), radioprotection level, were established through the development of a dosimetric methodology and the analysis of their physical parameters. The ionization chambers were studied in relation to their operational characteristics, and they were calibrated in X-ray beams (radioprotection, diagnostic radiology, mammography and radiotherapy levels) in accordance to international recommendations. They presented good performance. The determination procedure of personal dose equivalent, Hp (10), was established. (author)

  9. Evaluation of multiple scan average dose (MSAD) levels in computerized tomography in Minas Gerais state, Brazil

    International Nuclear Information System (INIS)

    Alonso, Thessa C.; Vieira, Leandro de A.; Barbosa, Nayra V.; Oliveira, Jeyselaine R. de; Cesar, Adriana C.Z.; Silva, Teogenes A. da

    2014-01-01

    Computed Tomography (CT) grows every year and is a diagnostic method that has revolutionized radiology with advances in procedures for obtaining image. However, the indiscriminate use of this method generates relatively high doses in patients. The diagnostic reference levels (DRLs) is a practical tool to promote the evaluation of existing protocols. The optimization and the periodic review of the protocols are important to balance the risk of radiation. The present study aims to conduct a survey of levels of MSAD of Minas Gerais following the procedures recommended by current Brazilian law. (author)

  10. Overview of the ICRP/ICRU adult reference computational phantoms and dose conversion coefficients for external idealised exposures

    International Nuclear Information System (INIS)

    Endo, Akira; Petoussi-Henss, Nina; Zankl, Maria; Schlattl, Helmut; Bolch, Wesley E.; Eckerman, Keith F.; Hertel, Nolan E.; Hunt, John G.; Pelliccioni, Maurizio; Menzel, Hans-Georg

    2014-01-01

    This paper reviews the ICRP Publications 110 and 116 describing the reference computational phantoms and dose conversion coefficients for external exposures. The International Commission on Radiological Protection (ICRP) in its 2007 Recommendations made several revisions to the methods of calculation of the protection quantities. In order to implement these recommendations, the DOCAL task group of the ICRP developed computational phantoms representing the reference adult male and female and then calculated a set of dose conversion coefficients for various types of idealised external exposures. This paper focuses on the dose conversion coefficients for neutrons and investigates their relationship with the conversion coefficients of the protection and operational quantities of ICRP Publication 74. Contributing factors to the differences between these sets of conversion coefficients are discussed in terms of the changes in phantoms employed and the radiation and tissue weighting factors. This paper briefly reviews the reference computational phantoms and dose conversion coefficients for external exposures that were published jointly by ICRP and ICRU. Both these publications appeared as a consequence of the ICRP 2007 Recommendations; to implement these recommendations, the ICRP has developed reference computational phantoms representing the adult male and female. These phantoms are used to calculate reference dose conversion coefficients for external and internal sources. Using the reference phantoms and methodology consistent with the 2007 Recommendations, dose conversion coefficients for both effective doses and organ-absorbed doses for various types of idealised external exposures have been calculated. These data sets supersede the existing ICRP/ICRU data sets and expand the particle types and energy ranges. For neutrons, the new effective dose conversion coefficients become smaller compared with those in ICRP74, for energies below hundreds of keV. This is mainly

  11. Method of evaluation of diagnostics reference levels in computerized tomography; Metodo de avaliacao de niveis de referencia de radiodiagnostico em tomografia computadorizada

    Energy Technology Data Exchange (ETDEWEB)

    Vega, Walter Flores

    1999-04-01

    Computerized tomography is a complex technique with several selectable exposition parameters delivering high doses to the patient. In this work it was developed a simple methodology to evaluate diagnostic reference levels in computerized tomography, using the concept of Multiple Scan Average Dose (MSAD), recently adopted by the Health Ministry. For evaluation of the MSAD, a dose distribution was obtained through a measured dose profile on the axial axis of a water phantom with thermoluminescence dosemeters, TLD-100, for different exam technique. The MSAD was evaluated hrough two distinct methods. First, it was evaluated by the integration of the dose profile of a single slice and, second, obtained by the integration on central slice of the profile of several slices. The latter is in of accordance with the ionization chamber method, suggesting to be the most practical method of dose evaluation to be applied in the diagnostic reference level assessment routine for CT, using TLDs. (author)

  12. Dose levels in the hot cells area ININ

    International Nuclear Information System (INIS)

    Torre, J. De la; Ramirez, J.M.; Solis, M.L.

    2004-01-01

    The Laboratory of Hot Cells (LCC) located in the National Institute of Nuclear Research (ININ) is an institution, it is an area where radioactive material is managed with different activity values, in function of its original design for 10,000 curies of Co-60. Managing this materials in the installation, it implies to measure and to analyze the dose levels that the POE will receive as well as the implementation of appropriate measures of radiological protection and radiological safety, so that that is completed settled down by the concept ALARA. In this work they are carried out mensurations of the levels of the dose to receive for the POE when managing radionuclides with maximum activities that can be allowed in function of the current conditions of the cells and an evaluation of the obtained results is made comparing them with the effective international norms as well as the application of the program of surveillance and radiological protection implemented for the development of the works that are carry out in the installation. (Author)

  13. TLD postal dose quality audit service for Co-60 beams in reference conditions in Cuba

    International Nuclear Information System (INIS)

    Gutierrez Lores, S.; Walwyn Salas, G.; Alonso Villanueva, G.

    2008-01-01

    This report presents the methodology and experience of the Cuban's Secondary Standard Dosimetry Laboratory for the implementation of postal dose quality audits service for Co-60 beams in reference conditions, using TLDs. Under coordinated research project (Contract 10794) were bought (TLD -100) Tl rods type JR 1152F made in China, with dimensions of 6 mm x 1 mm x 1 mm. All of these rods were identified individually with a consecutive number made over one of its sides, using a fine tip of graphite. The method used to determinate the individual sensibility of the TL detectors was: irradiating a group of them, with the same history of irradiation and readout (100 rods approximately), four serial times in the same geometrical conditions, to read them out and to attribute to each of them a sensitivity factor. This sensitivity factor is equal to average for the 4 cycle of irradiation and readout of the quote between the TL readout from dosimeter i and the mean of all values for each cycle. The TLD signal was read using HARSHAW 2000C/B reader. The results obtained in the external verification of the accuracy of the dose determination by the TLD system were performed in cooperation with IAEA Dosimetry Laboratory at Seibersdorf in different years are shown, the results obtained of the quality audits carried out to the different services of radiotherapy of the country are analysed also. The quality audits are an useful tool for the improvement of the accuracy in the dosimetry of clinical beams of radiotherapy with Co-60, contributing this way to the improvement of the life quality to cancer patients of the Cuban system of health. (author)

  14. Diagnostic reference levels and complexity indices in interventional radiology: a national programme

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Cruces, R.; Perez-Martinez, M.; Pastor-Vega, J.M.; Canete, S. [University of Malaga, School of Medicine, Malaga (Spain); Vano, E.; Fernandez-Soto, J.M.; Sanchez-Casanueva, R.; Gallego-Beuter, J.J. [Complutense University, San Carlos Hospital, Medical School, Madrid (Spain); Carrera-Magarino, F.; Moreno-Rodriguez, F.; Moreno-Sanchez, T. [Juan Ramon Jimenez University Hospital, Huelva (Spain); Soler-Cantos, M.M.; Canis-Lopez, M. [Reina Sofia University Hospital, Cordoba (Spain); Hernandez-Armas, J.; Diaz-Romero, F.J. [University Hospital of Canary Islands, Tenerife (Spain); Rosales-Espizua, F.; Lopez-Medina, A.; Gonzalez-de-Garay, M. [Basurto Hospital, Bilbao (Spain); Martin-Palanca, A. [Virgen de la Victoria University Hospital, Malaga (Spain); Gil-Agudo, A.; Zarca-Diaz, M.A.; Zapata-Jimenez, J.C. [General University Hospital, Ciudad Real (Spain); Parra-Osorio, V.; Munoz Ruiz-Canela, J.J.; Moreno-Saiz, C.; Galan-Montenegro, P. [Carlos Haya University Hospital, Malaga (Spain)

    2016-12-15

    To propose national diagnostic reference levels (DRLs) for interventional radiology and to evaluate the impact of the procedural complexity on patient doses. Eight interventional radiology units from Spanish hospitals were involved in this project. The participants agreed to undergo common quality control procedures for X-ray systems. Kerma area product (KAP) was collected from a sample of 1,649 procedures. A consensus document established the criteria to evaluate the complexity of seven types of procedures. DRLs were set as the 3rd quartile of KAP values. The KAP (3rd quartile) in Gy cm{sup 2} for the procedures included in the survey were: lower extremity arteriography (n = 784) 78; renal arteriography (n = 37) 107; transjugular hepatic biopsies (THB) (n = 30) 45; biliary drainage (BD) (n = 314) 30; uterine fibroid embolization (UFE) (n = 56) 214; colon endoprostheses (CE) (n = 31) 169; hepatic chemoembolization (HC) (n = 269) 303; femoropopliteal revascularization (FR) (n = 62) 119; and iliac stent (n = 66) 170. The complexity involved the increases in the following KAP factors from simple to complex procedures: THB x4; BD x13; UFE x3; CE x3; HC x5; FR x5 and IS x4. The evaluation of the procedure complexity in patient doses will allow the proper use of DRLs for the optimization of interventional radiology. (orig.)

  15. Reference computations of public dose and cancer risk from airborne releases of uranium and Class W plutonium

    International Nuclear Information System (INIS)

    Peterson, V.L.

    1995-01-01

    This report presents ''reference'' computations that can be used by safety analysts in the evaluations of the consequences of postulated atmospheric releases of radionuclides from the Rocky Flats Environmental Technology Site. These computations deal specifically with doses and health risks to the public. The radionuclides considered are Class W Plutonium, all classes of Enriched Uranium, and all classes of Depleted Uranium. (The other class of plutonium, Y, was treated in an earlier report.) In each case, one gram of the respirable material is assumed to be released at ground leveL both with and without fire. The resulting doses and health risks can be scaled to whatever amount of release is appropriate for a postulated accident being investigated. The report begins with a summary of the organ-specific stochastic risk factors appropriate for alpha radiation, which poses the main health risk of plutonium and uranium. This is followed by a summary of the atmospheric dispersion factors for unfavorable and typical weather conditions for the calculation of consequences to both the Maximum Offsite Individual and the general population within 80 km (50 miles) of the site

  16. Comparison of internal dose estimates obtained using organ-level, voxel S value, and Monte Carlo techniques

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, Joshua, E-mail: grimes.joshua@mayo.edu [Department of Physics and Astronomy, University of British Columbia, Vancouver V5Z 1L8 (Canada); Celler, Anna [Department of Radiology, University of British Columbia, Vancouver V5Z 1L8 (Canada)

    2014-09-15

    Purpose: The authors’ objective was to compare internal dose estimates obtained using the Organ Level Dose Assessment with Exponential Modeling (OLINDA/EXM) software, the voxel S value technique, and Monte Carlo simulation. Monte Carlo dose estimates were used as the reference standard to assess the impact of patient-specific anatomy on the final dose estimate. Methods: Six patients injected with{sup 99m}Tc-hydrazinonicotinamide-Tyr{sup 3}-octreotide were included in this study. A hybrid planar/SPECT imaging protocol was used to estimate {sup 99m}Tc time-integrated activity coefficients (TIACs) for kidneys, liver, spleen, and tumors. Additionally, TIACs were predicted for {sup 131}I, {sup 177}Lu, and {sup 90}Y assuming the same biological half-lives as the {sup 99m}Tc labeled tracer. The TIACs were used as input for OLINDA/EXM for organ-level dose calculation and voxel level dosimetry was performed using the voxel S value method and Monte Carlo simulation. Dose estimates for {sup 99m}Tc, {sup 131}I, {sup 177}Lu, and {sup 90}Y distributions were evaluated by comparing (i) organ-level S values corresponding to each method, (ii) total tumor and organ doses, (iii) differences in right and left kidney doses, and (iv) voxelized dose distributions calculated by Monte Carlo and the voxel S value technique. Results: The S values for all investigated radionuclides used by OLINDA/EXM and the corresponding patient-specific S values calculated by Monte Carlo agreed within 2.3% on average for self-irradiation, and differed by as much as 105% for cross-organ irradiation. Total organ doses calculated by OLINDA/EXM and the voxel S value technique agreed with Monte Carlo results within approximately ±7%. Differences between right and left kidney doses determined by Monte Carlo were as high as 73%. Comparison of the Monte Carlo and voxel S value dose distributions showed that each method produced similar dose volume histograms with a minimum dose covering 90% of the volume (D90

  17. Estimating Radiological Doses to Predators Foraging in a Low-Level Radioactive Waste Management Area

    International Nuclear Information System (INIS)

    L.Soholt; G.Gonzales; P.Fresquez; K.Bennett; E.Lopez

    2003-01-01

    Since 1957, Los Alamos National Laboratory has operated Area G as its low-level, solid radioactive waste management and disposal area. Although the waste management area is developed, plants, small mammals, and avian and mammalian predators still occupy the less disturbed and revegetated portions of the land. For almost a decade, we have monitored the concentrations of selected radionuclides in soils, plants, and small mammals at Area G. The radionuclides tritium, plutonium-238, and plutonium-239 are regularly found at levels above regional background in all three media. Based on radionuclide concentrations in mice collected from 1994 to 1999, we calculated doses to higher trophic levels (owl, hawk, kestrel, and coyote) that forage on the waste management area. These predators play important functions in the regional ecosystems and are an important part of local Native American traditional tales that identify the uniqueness of their culture. The estimated doses are compared to Department of Energy's interim limit of 0.1 rad/day for the protection of terrestrial wildlife. We used exposure parameters that were derived from the literature for each receptor, including Environmental Protection Agency's exposure factors handbook. Estimated doses to predators ranged from 9E-06 to 2E-04 rad/day, assuming that they forage entirely on the waste management area. These doses are greater than those calculated for predators foraging exclusively in reference areas, but are still well below the interim dose limit. We believe that these calculated doses represent upper-bound estimates of exposure for local predators because the larger predators forage over areas that are much greater than the 63-acre waste management area. Based on these results, we concluded that predators foraging on this area do not face a hazard from radiological exposure under current site conditions

  18. Issues raised by the reference doses for perfluorooctane sulfonate and perfluorooctanoic acid.

    Science.gov (United States)

    Dong, Zhaomin; Bahar, Md Mezbaul; Jit, Joytishna; Kennedy, Bruce; Priestly, Brian; Ng, Jack; Lamb, Dane; Liu, Yanju; Duan, Luchun; Naidu, Ravi

    2017-08-01

    On 25th May 2016, the U.S. EPA released reference doses (RfDs) for Perfluorooctane Sulfonate (PFOS) and Perfluorooctanoic Acid (PFOA) of 20ng/kg/day, which were much more conservative than previous values. These RfDs rely on the choices of animal point of departure (PoD) and the toxicokinetics (TK) model. At this stage, considering that the human evidence is not strong enough for RfD determination, using animal data may be appropriate but with more uncertainties. In this article, the uncertainties concerning RfDs from the choices of PoD and TK models are addressed. Firstly, the candidate PoDs should include more critical endpoints (such as immunotoxicity), which may lead to lower RfDs. Secondly, the reliability of the adopted three-compartment TK model is compromised: the parameters are not non-biologically plausible; and this TK model was applied to simulate gestation and lactation exposures, while the two exposure scenarios were not actually included in the model structure. Copyright © 2017. Published by Elsevier Ltd.

  19. Diagnostic reference levels for X-ray investigations in pain management units in Belgium

    International Nuclear Information System (INIS)

    Lichtherte, S.; Le Polain de Waroux, B.

    2008-01-01

    X-rays are commonly used in pain treatment centres where infiltrative techniques are performed. Although X-rays are useful in increasing the precision of infiltrative techniques, their use puts patients and staff at risk of radiation exposure. As a result, medical staff now have to obtain a certificate of training on the use of X-rays before being allowed to use X-rays in practice. This analysis was based on 373 detailed registrations of procedure-related parameters in the six centres that participated in this study between January 2009 and July 2009. Examinations chosen for inclusion in this study were the most commonly performed fluoroscopic imaging-guided procedures in a pain management unit: epidural (cervical/lumbar), facet joint nerve blocks (cervical/lumbar) and trans-foraminal (cervical/lumbar). The sample size, the dose-area product (DAP) range for whole population, the mean and the third quartile DAP corrected for patient size (DAP corr ), the screening time range, the mean and the third quartile screening time are presented. The proposed DRLs for epidural, facet joint nerve blocks and trans-foraminal are 0.5, 2.5 and 3 Gy cm 2 for DAP values and 12, 60 and 50 s for screening times, respectively. In the absence of national diagnostic reference levels (DRLs) for pain management fluoroscopic procedures, these DAP and screening time values provide a possible way of establishing provisional DRLs for local use. The values for each examination type could be used as a baseline against which to monitor the effectiveness of dose reduction strategies as part of the optimisation process that is the goal of any quality control and patient dose monitoring system. (authors)

  20. Development of a low-level radon reference chamber; Entwicklung einer Low-Level-Radon-Referenzkammer

    Energy Technology Data Exchange (ETDEWEB)

    Linzmaier, Diana

    2013-01-04

    The naturally occurring, radioactive noble gas radon-222 exists worldwide in different activity concentrations in the air. During the decay of radon-222, decay products are generated which are electrically charged and attach to aerosols in the air. Together with the aerosols, the radon is inhaled and exhaled by humans. While the radon is nearly completely exhaled, ca. 20 % of the inhaled aerosols remain in the lungs in one breath cycle. Due to ionizing radiation, in a chain of events, lung cancer might occur. Consequently, radon and its decay products are according to the current findings the second leading cause of lung cancer. At the workplace and in the home measurements of radon activity concentration are performed to determine the radiation exposition of humans. All measurement devices for the determination of radon activity concentration are calibrated above 1000 Bq/m{sup 3}, even though the mean value of the present investigation in Germany shows only 50 Bq/m{sup 3}. For the calibration of measurement devices in the range below 1000 Bq/m{sup 3} over a long time period, the generation of a stable reference atmosphere is presented in this work. Due to a long term calibration (t>5 days) of the measurement devices, smaller uncertainties result for the calibration factor. For the calibration procedure, a so-called low-level radon reference chamber was set up and started operation. The generation of a stable reference atmosphere is effected by means of emanation sources which consist of a radium-226 activity standard. On the basis of {gamma}-spectrometry, the effective emanation coefficient ofthe emanation sources is determined. The traceability of the activity concentration in the reference volume is realized via the activity ofthe radium-226, the emanation coefficient and the volume. With the emanation sources produced, stable reference atmospheres within the range of 150 Bq/m{sup 3} to 1900 Bq/m{sup 3} are achieved. For the realization, maintenance and

  1. Epidemiological surveys on the effects of low-level radiation dose: a comparative assessment

    International Nuclear Information System (INIS)

    Rose, K.S.B.

    1988-01-01

    In this report, the health effects of low-level doses of radiation are considered by reference to published epidemiological surveys. The work was carried out with three objectives in mind: 1. to provide a comprehensive and critical review of the subject; 2. to seek consistent indications of particular health effects by collating results and comparing with those from surveys at moderate-level doses; 3. to provide an authoritative view on the epidemiology of low-level radiation-induced health effects. Vol E (DRAFT A) is appended and contains group collation tables. Epidemiological surveys can be conveniently divided into four classes (A, B, C, D) according to the phase of life when irradiation occurs or the effect is diagnosed. The first of the classes (A) is addressed here; this class is concerned with possible effects arising from radiation received by a parent before conception. Possible effects of preconception irradiation were identified under four broad groupings. These are Down's syndrome, ''Indicators of Reproductive Damage'' (mainly Primary Sterility, Congenital Abnormalities, Sex Ratio, Fetal Mortality, Infant Mortality), Childhood Malignancies, and Chromosomal Changes in Abortuses. Information about each survey, and comparisons with results from moderate-level dose surveys, are contained in synopses that are set out in the Appendix. (author)

  2. The calculation of dose from photon exposures using reference human phantoms and Monte Carlo methods. Pt. 5

    International Nuclear Information System (INIS)

    Petoussi, N.; Zankl, M.; Williams, G.; Veit, R.; Drexler, G.

    1987-01-01

    There has been some evidence that cervical cancer patients who were treated by radiotherapy, had an increased incidence of second primary cancers noticeable 15 years or more after the radiotherapy. The data suggested that high dose pelvic irradiation was associated with increase in cancers of the bladder, kidneys, rectum, ovaries, corpus uteri, and non-Hodgkin's lymphoma but not leukemia (Kleinerman et al., 1982, Morton 1973). The aim of the present work is to estimate the absorbed dose, due to radiotherapy treatment for cervival cancer, to various organs and tissues in the body. Monte Carlo calculations were performed to calculate the organ absorbed doses resulting from intracavitary sources such as ovoids and applicators filled or loaded with radium, Co-60 and Cs-137. For that purpose a routine which simulates an internal source was constructed and added to the existing Monte Carlo code (GSF-Bericht S-885, Kramer et al.). Calculations were also made for external beam therapy. Various anterior, posterior and lateral fields were applied, resulting from megavoltage, Co-60 and Cs-137 therapy machines. The calculated organ doses are tabulated in three different ways: as organ dose per air Kerma in the reference field, according to the recommendations of the International Commission on Radiation Units and Measurements (ICRU Report No 38, 1985); as organ dose per surface dose and as organ dose per tissue dose at Point B. (orig.)

  3. Organ dose conversion coefficients for voxel models of the reference male and female from idealized photon exposures

    International Nuclear Information System (INIS)

    Schlattl, H; Zankl, M; Petoussi-Henss, N

    2007-01-01

    A new series of organ equivalent dose conversion coefficients for whole body external photon exposure is presented for a standardized couple of human voxel models, called Rex and Regina. Irradiations from broad parallel beams in antero-posterior, postero-anterior, left- and right-side lateral directions as well as from a 360 deg. rotational source have been performed numerically by the Monte Carlo transport code EGSnrc. Dose conversion coefficients from an isotropically distributed source were computed, too. The voxel models Rex and Regina originating from real patient CT data comply in body and organ dimensions with the currently valid reference values given by the International Commission on Radiological Protection (ICRP) for the average Caucasian man and woman, respectively. While the equivalent dose conversion coefficients of many organs are in quite good agreement with the reference values of ICRP Publication 74, for some organs and certain geometries the discrepancies amount to 30% or more. Differences between the sexes are of the same order with mostly higher dose conversion coefficients in the smaller female model. However, much smaller deviations from the ICRP values are observed for the resulting effective dose conversion coefficients. With the still valid definition for the effective dose (ICRP Publication 60), the greatest change appears in lateral exposures with a decrease in the new models of at most 9%. However, when the modified definition of the effective dose as suggested by an ICRP draft is applied, the largest deviation from the current reference values is obtained in postero-anterior geometry with a reduction of the effective dose conversion coefficient by at most 12%

  4. Organ dose conversion coefficients for voxel models of the reference male and female from idealized photon exposures

    Science.gov (United States)

    Schlattl, H.; Zankl, M.; Petoussi-Henss, N.

    2007-04-01

    A new series of organ equivalent dose conversion coefficients for whole body external photon exposure is presented for a standardized couple of human voxel models, called Rex and Regina. Irradiations from broad parallel beams in antero-posterior, postero-anterior, left- and right-side lateral directions as well as from a 360° rotational source have been performed numerically by the Monte Carlo transport code EGSnrc. Dose conversion coefficients from an isotropically distributed source were computed, too. The voxel models Rex and Regina originating from real patient CT data comply in body and organ dimensions with the currently valid reference values given by the International Commission on Radiological Protection (ICRP) for the average Caucasian man and woman, respectively. While the equivalent dose conversion coefficients of many organs are in quite good agreement with the reference values of ICRP Publication 74, for some organs and certain geometries the discrepancies amount to 30% or more. Differences between the sexes are of the same order with mostly higher dose conversion coefficients in the smaller female model. However, much smaller deviations from the ICRP values are observed for the resulting effective dose conversion coefficients. With the still valid definition for the effective dose (ICRP Publication 60), the greatest change appears in lateral exposures with a decrease in the new models of at most 9%. However, when the modified definition of the effective dose as suggested by an ICRP draft is applied, the largest deviation from the current reference values is obtained in postero-anterior geometry with a reduction of the effective dose conversion coefficient by at most 12%.

  5. Radioactivity levels of basic foodstuffs and dose estimates in Sudan

    International Nuclear Information System (INIS)

    Hemada, H. E. F.

    2009-03-01

    In this work a comprehensive study was carried out for the determination of different radionuclides activities in foodstuff consumed and evaluation of dose levels in different food stuffs were collected from eight States in Sudan (cereals, vegetables, meat, fruits, milk, and fermented milk, baby milk, cans, spices, additives, others). The concentrations of different radionuclides in the food samples were determined by gamma spectrometry using an HPGe detector. Radionuclides observed include: Bi-212, Bi-214, Cs-134, Cs-137, K-40, Pb-212, Pb-214, Ra-224, Ra-226, Th-228, Ac-228, TI-208, Th-232, and U-238. The activity concentration of these radionuclides were found in the following ranges: 0.51 - 19.42 Bq/Kg, 0.47 - 12.13 Bq/kg, 0.5 - 1.29 Bq/kg, 0.001 - 3.41 Bq/kg, 19.25 -2521.82 Bq/kg, 0.08 - 6.84 Bq/kg, 0.02 - 6.87 Bq/kg, 6.08 - 32.02 Bq/kg, 0.03 - 21. 53 Bq/kg, 0.92 - 26.77 Bq/kg, 0.91 - 1200 Bq/kg, 0.14 - 2.58 Bq/Kg, 0.03 - 9.65 Bq/kg, 0.03 - 9.65 Bq/kg and 0.82 - 5.27 Bq/kg respectively. High concentrations were typically found in portulaca, the lowest concentrations were found in barley and bread additives. The annual effective dose due to the different foodstuff estimated was found to be 2.78±0.44 mSv/y and 1.18±mSv/y for age categories 7-12 y and> 17y respectively. (Author)

  6. Forget the Desk Job: Current Roles and Responsibilities in Entry-Level Reference Job Advertisements

    Science.gov (United States)

    Detmering, Robert; Sproles, Claudene

    2012-01-01

    This study examines the evolving roles and responsibilities of entry-level academic reference positions, as stated in recent job advertisements posted on the American Library Association's JobLIST Web site and other sources. Findings from a content analysis of these advertisements indicate that current entry-level reference positions in academic…

  7. Analysis of Surface Dose Refer to Distance between Beam Spoiler and Patient in Total Body Irradiation

    International Nuclear Information System (INIS)

    Choi, Jong Hwan; Kim, Jong Sik; Choi, Ji Min; Shin, Eun Hyuk; Song, Ki Won; Park, Young Hwan

    2007-01-01

    Total body irradiation is used to kill the total malignant cell and for immunosuppression component of preparatory regimens for bone-marrow restitution of patients. Beam spoiler is used to increase the dose to the superficial tissues. This paper finds the property of the distance between beam spoiler and patient. Set-up conditions are 6 MV-Xray, 300 MU, SAD = 400 cm, field size = 40 x 40 cm 2 . The parallel plate chamber located in surface, midpoint and exit of solid water phantom. The surface dose is measured while the distance between beam spoiler and patient is altered. Because it should be found proper distance. The solid water phantom is fixer and beam spoiler is moving. Central dose of phantom is 10.7 cGy and exit dose is 6.7 cGy. In case of distance of 50 cm to 60 cm between beam spoiler and solid water phantom, incidence dose is 14.58-14.92 cGy. Therefore, The surface dose was measured 99.4-101% with got near most to the prescription dose. In clinical case, distance between beam spoiler and patient affect surface dose. If once 50-60 cm of distance between beam spoiler and patient, surface dose of patient got near prescription dose. It would be taken distance between beam spoiler and patient into account in clinical therapy.

  8. Reference beta radiations for calibrating dosemeters and dose ratemeters and for determining their response as a function of beta radiation energy. 1. ed.

    International Nuclear Information System (INIS)

    1984-01-01

    This International Standard specifies the requirements for reference beta radiations produced by radionuclide sources to be used for the calibration of protection level dosemeters and dose ratemeters, and for the determination of their response as a function of beta energy. It gives the characteristics of radionuclides which have been used to produce reference beta radiations, gives examples of suitable source constructions and describes methods for the measurement of the residual maximum beta energy and the absorbed dose rate at a depth of 7 mg·cm -2 in a semi-infinite tissue-equivalent medium. The energy range involved lies between 66 keV and 3.6 MeV and the absorbed dose rates are in the range from about 10 μGy·h -1 (1 mrad·h -1 ) to at least 10 Gy·h -1 (10 3 rad·h -1 ). This International Standard proposes two series of beta reference radiations from which the radiation necessary for determining the characteristics (calibration and energy response) of an instrument shall be selected. Series 1 reference radiations are produced by radionuclide sources used with beam flattening filters designed to give uniform dose rates over a large area at a specific distance. The proposed sources of 90 Sr+ 90 Y, 204 TI and 147 Pm produce maximum dose rates of approximately 5mGy·h -1 (0.5 rad·h -1 ). Series 2 reference radiations are produced without the use of beam flattening filters which allows a range of source-to-calibration plane distances to be used. Close to the sources only relatively small areas of uniform dose rate are produced but this Series has the advantage of extending the energy and dose rate ranges beyond those of Series 1. The radionuclides used are those of Series 1 with the addition of the radionuclides 14 C and 106 Ru+ 106 Rh; these sources produce dose rates of up to 10 Gy·h -1 (10 3 rad·h -1 )

  9. Overview of the ICRP/ICRU adult reference computational phantoms and dose conversion coefficients for external idealised exposures

    CERN Document Server

    Endo, A; Zankl, M; Bolch, W E; Eckerman, K F; Hertel, N E; Hunt, J G; Pelliccioni, M; Schlattl, H; Menzel, H-G

    2014-01-01

    This paper reviews the ICRP Publications 110 and 116 describing the reference computational phantoms and dose conversion coefficients for external exposures. The International Commission on Radiological Protection (ICRP) in its 2007 Recommendations made several revisions to the methods of calculation of the protection quantities. In order to implement these recommendations, the DOCAL task group of the ICRP developed computational phantoms representing the reference adult male and female and then calculated a set of dose conversion coefficients for various types of idealised external exposures. This paper focuses on the dose conversion coefficients for neutrons and investigates their relationship with the conversion coefficients of the protection and operational quantities of ICRP Publication 74. Contributing factors to the differences between these sets of conversion coefficients are discussed in terms of the changes in phantoms employed and the radiation and tissue weighting factors.

  10. Order of 24 October 2011 related to diagnosis reference levels in radiology and nuclear medicine; Arrete du 24 octobre 2011 relatif aux niveaux de reference diagnostiques en radiologie et en medecine nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Grall, J.Y. [Ministere du travail, de l' emploi et de la sante, Direction generale de la sante, 14, avenue Duquesne, 75350 PARIS 07 SP (France)

    2012-01-14

    This order defines diagnosis reference levels for examinations exposing to the most common or irradiating ionizing radiations in the case of radiology and nuclear medicine. It also specifies the role of the person authorized to use nuclear medicine equipment, the role of the IRSN in collecting and analysing data. Doses are specified in appendix for different types of examinations

  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. Organ doses, effective doses, and risk indices in adult CT: Comparison of four types of reference phantoms across different examination protocols

    International Nuclear Information System (INIS)

    Zhang Yakun; Li Xiang; Paul Segars, W.; Samei, Ehsan

    2012-01-01

    Purpose: Radiation exposure from computed tomography (CT) to the public has increased the concern among radiation protection professionals. Being able to accurately assess the radiation dose patients receive during CT procedures is a crucial step in the management of CT dose. Currently, various computational anthropomorphic phantoms are used to assess radiation dose by different research groups. It is desirable to better understand how the dose results are affected by different choices of phantoms. In this study, the authors assessed the uncertainties in CT dose and risk estimation associated with different types of computational phantoms for a selected group of representative CT protocols. Methods: Routinely used CT examinations were categorized into ten body and three neurological examination categories. Organ doses, effective doses, risk indices, and conversion coefficients to effective dose and risk index (k and q factors, respectively) were estimated for these examinations for a clinical CT system (LightSpeed VCT, GE Healthcare). Four methods were used, each employing a different type of reference phantoms. The first and second methods employed a Monte Carlo program previously developed and validated in our laboratory. In the first method, the reference male and female extended cardiac-torso (XCAT) phantoms were used, which were initially created from the Visible Human data and later adjusted to match organ masses defined in ICRP publication 89. In the second method, the reference male and female phantoms described in ICRP publication 110 were used, which were initially developed from tomographic data of two patients and later modified to match ICRP 89 organ masses. The third method employed a commercial dosimetry spreadsheet (ImPACT group, London, England) with its own hermaphrodite stylized phantom. In the fourth method, another widely used dosimetry spreadsheet (CT-Expo, Medizinische Hochschule, Hannover, Germany) was employed together with its associated

  13. Organ doses, effective doses, and risk indices in adult CT: Comparison of four types of reference phantoms across different examination protocols

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yakun; Li Xiang; Paul Segars, W.; Samei, Ehsan [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Carl E. Ravin Advanced Imaging Laboratories, Duke University, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Duke University, Durham, North Carolina 27705 and Department of Radiology, Duke University, Durham, North Carolina 27705 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Duke University, Durham, North Carolina 27705 (United States) and Department of Radiology, Duke University, Durham, North Carolina 27705 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Duke University, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University, Durham, North Carolina 27705 (United States) and Departments of Physics, Biomedical Engineering, and Electrical and Computer Engineering, Duke University, Durham, North Carolina 27705 (United States)

    2012-06-15

    Purpose: Radiation exposure from computed tomography (CT) to the public has increased the concern among radiation protection professionals. Being able to accurately assess the radiation dose patients receive during CT procedures is a crucial step in the management of CT dose. Currently, various computational anthropomorphic phantoms are used to assess radiation dose by different research groups. It is desirable to better understand how the dose results are affected by different choices of phantoms. In this study, the authors assessed the uncertainties in CT dose and risk estimation associated with different types of computational phantoms for a selected group of representative CT protocols. Methods: Routinely used CT examinations were categorized into ten body and three neurological examination categories. Organ doses, effective doses, risk indices, and conversion coefficients to effective dose and risk index (k and q factors, respectively) were estimated for these examinations for a clinical CT system (LightSpeed VCT, GE Healthcare). Four methods were used, each employing a different type of reference phantoms. The first and second methods employed a Monte Carlo program previously developed and validated in our laboratory. In the first method, the reference male and female extended cardiac-torso (XCAT) phantoms were used, which were initially created from the Visible Human data and later adjusted to match organ masses defined in ICRP publication 89. In the second method, the reference male and female phantoms described in ICRP publication 110 were used, which were initially developed from tomographic data of two patients and later modified to match ICRP 89 organ masses. The third method employed a commercial dosimetry spreadsheet (ImPACT group, London, England) with its own hermaphrodite stylized phantom. In the fourth method, another widely used dosimetry spreadsheet (CT-Expo, Medizinische Hochschule, Hannover, Germany) was employed together with its associated

  14. Uncertainty and power at low levels of incurred radiation dose

    International Nuclear Information System (INIS)

    Wilson, M; Jackson, D

    2005-01-01

    It is common practice when calculating dose to exposed populations to average the variables that go into the dose calculation (e.g. environmental concentrations, air kerma, consumption rates, occupancy rates). This approach is simple and can be useful where data are obtained over different periods (weekly, monthly, quarterly), where samples may be bulked for some analyses but not others and where gaps in the data are present. However, such an approach does not yield information on the degree of uncertainty around the average dose calculated. An alternative approach is to estimate the dose to each individual and to obtain an average from this data set, which can then also be used to derive a measure of uncertainty around the central dose estimate. In this study, we demonstrate the variability in dose estimates using a hypothetical data set and consider the implications for sample size to achieve fixed confidence or resolving power. We recommend calculating the dose to every individual sampled, in order both to obtain the average dose and to estimate its variability. We argue that it is best practice to obtain information as complete as possible from the available sample of individuals

  15. Carcinogenesis and low-level ionizing radiation with special reference to lung cancer and exposure to radon daughters

    Energy Technology Data Exchange (ETDEWEB)

    Fabrikant, J.I.

    1982-04-01

    Of the important health effects of ionizing radiation, three important late effects - carcinogenesis, teratogenesis and mutagenesis are of greatest concern. This is because any exposure, even at low levels, carries some risk of such deleterious effects. As the dose of radiation increases above very low levels, the risk of health effects increases. Cancer-induction is the most important late somatic effect of low-dose ionizing radiation. Solid cancers, rather than leukemia, are principal late effects in exposed individuals. Tissues vary greatly in their susceptibility to radiation carcinogenesis. The most frequently occurring radiation-induced cancers in man include, in decreasing order of susceptibility: the female breast, the thyroid gland, the blood-forming tissues, the lung, certain organs of the gastrointestinal tract, and the bones. A number of biological and physical factors affect the cancer risk, such as age, sex, life-style, LET, and RBE. Despite uncertainty about low-level radiation risks, regulatory and advisory bodies must set standards for exposure, and individuals need information to be able to make informed judgments for themselves. From the point of view of the policy maker, the overriding concern is the fact that small doses of radiation can cause people to have more cancers than would otherwise be expected. While concern for all radiation effects exists, our human experience is limited to cancer-induction in exposed populations. This discussion is limited to cancer risk estimation and decision-making in relation to the health effects on populations of exposure to low levels of ionizing radiation. Here, low-level radiation will refer to yearly whole-body doses up to 5 rems or 0.05 Sv, or to cumulative doses up to 50 rems or 0.5 Sv from low-LET radiation and from high-LET radiation. (ERB)

  16. Carcinogenesis and low-level ionizing radiation with special reference to lung cancer and exposure to radon daughters

    International Nuclear Information System (INIS)

    Fabrikant, J.I.

    1982-04-01

    Of the important health effects of ionizing radiation, three important late effects - carcinogenesis, teratogenesis and mutagenesis are of greatest concern. This is because any exposure, even at low levels, carries some risk of such deleterious effects. As the dose of radiation increases above very low levels, the risk of health effects increases. Cancer-induction is the most important late somatic effect of low-dose ionizing radiation. Solid cancers, rather than leukemia, are principal late effects in exposed individuals. Tissues vary greatly in their susceptibility to radiation carcinogenesis. The most frequently occurring radiation-induced cancers in man include, in decreasing order of susceptibility: the female breast, the thyroid gland, the blood-forming tissues, the lung, certain organs of the gastrointestinal tract, and the bones. A number of biological and physical factors affect the cancer risk, such as age, sex, life-style, LET, and RBE. Despite uncertainty about low-level radiation risks, regulatory and advisory bodies must set standards for exposure, and individuals need information to be able to make informed judgments for themselves. From the point of view of the policy maker, the overriding concern is the fact that small doses of radiation can cause people to have more cancers than would otherwise be expected. While concern for all radiation effects exists, our human experience is limited to cancer-induction in exposed populations. This discussion is limited to cancer risk estimation and decision-making in relation to the health effects on populations of exposure to low levels of ionizing radiation. Here, low-level radiation will refer to yearly whole-body doses up to 5 rems or 0.05 Sv, or to cumulative doses up to 50 rems or 0.5 Sv from low-LET radiation and from high-LET radiation

  17. Single dose antidepressant administration modulates the neural processing of self-referent personality trait words

    DEFF Research Database (Denmark)

    Miskowiak, Kamilla; Papadatou-Pastou, Marietta; Cowen, Philip J

    2007-01-01

    categorisation and recognition of self-referent personality trait words were assessed using event-related functional Magnetic Resonance Imaging (fMRI). Reboxetine had no effect on neuronal response during self-referent categorisation of positive or negative personality trait words. However, in a subsequent...

  18. Natural radiation level and doses to population in Anhui province

    International Nuclear Information System (INIS)

    1985-01-01

    The absorbed dose rates in air 1 m above the ground from natural radiation and terrestrial gamma radiation in Anhui Province were surveyed. One measurement was made in every area of 90 km 2 . The absorbed dose rates in air from terrestrial radiation range from 54 to 90 nGy.h -1 with an average of 70 nGy.h -1 . The ratios of indoors-to-outdoors and of roads-to-outdoors are 1.5 and 0.9 respectively. The annual effective dose equivalent from external radiation is 0.68-1.05 mSv. The population-weighted average values for mountain area, plain, hilly land, and the Changjiang River basin as well as the annual collective effective dose equivalent were calculated

  19. Dose specification and normal tissue reference points in the treatment of cancer cervix

    International Nuclear Information System (INIS)

    Ray, D.K.; Kumar, P.; Misra, D.K.; Das, R.; Kumar, A.; Maji, T.; Chaudhuri, P.; Sinha, T.P.

    2007-01-01

    Carcinoma of uterine cervix is one of the most common diseases among the women in India where radiotherapy is the mainstay of treatment. Most common practice of dose prescription point is the Manchester Point A. American Brachytherapy Society (ABS) recommends a point H equivalent to that used in the classical Manchester system. Many centre practices Madison point M as dose specification point which is 20 mm cephaled along the tandem from a line joining the mid dwell positions in the ovoids/ring and 20 mm lateral to the tandem. In the present study has compared the dose prescription points between Manchester Point A and Madison Point M for ring applicators and their implication in the assessment of rectal and bladder doses in patients of Carcinoma of uterine cervix

  20. Hearing Tests on Mobile Devices: Evaluation of the Reference Sound Level by Means of Biological Calibration.

    Science.gov (United States)

    Masalski, Marcin; Kipiński, Lech; Grysiński, Tomasz; Kręcicki, Tomasz

    2016-05-30

    Hearing tests carried out in home setting by means of mobile devices require previous calibration of the reference sound level. Mobile devices with bundled headphones create a possibility of applying the predefined level for a particular model as an alternative to calibrating each device separately. The objective of this study was to determine the reference sound level for sets composed of a mobile device and bundled headphones. Reference sound levels for Android-based mobile devices were determined using an open access mobile phone app by means of biological calibration, that is, in relation to the normal-hearing threshold. The examinations were conducted in 2 groups: an uncontrolled and a controlled one. In the uncontrolled group, the fully automated self-measurements were carried out in home conditions by 18- to 35-year-old subjects, without prior hearing problems, recruited online. Calibration was conducted as a preliminary step in preparation for further examination. In the controlled group, audiologist-assisted examinations were performed in a sound booth, on normal-hearing subjects verified through pure-tone audiometry, recruited offline from among the workers and patients of the clinic. In both the groups, the reference sound levels were determined on a subject's mobile device using the Bekesy audiometry. The reference sound levels were compared between the groups. Intramodel and intermodel analyses were carried out as well. In the uncontrolled group, 8988 calibrations were conducted on 8620 different devices representing 2040 models. In the controlled group, 158 calibrations (test and retest) were conducted on 79 devices representing 50 models. Result analysis was performed for 10 most frequently used models in both the groups. The difference in reference sound levels between uncontrolled and controlled groups was 1.50 dB (SD 4.42). The mean SD of the reference sound level determined for devices within the same model was 4.03 dB (95% CI 3

  1. Analysis of data related to the update of diagnosis reference levels in radiology and nuclear medicine. Assessment 2009-2010

    International Nuclear Information System (INIS)

    Roch, Patrice; Celier, David

    2012-10-01

    This report presents and comments the results of the analysis of 'patient' dosimetric data which radiology and nuclear medicine establishments had to transmit to the IRSN. The first part concerns conventional radiology and the analysis is made from a general point of view, and then by examination type (in the case of adults and of children). A synthesis of results since 2004 is proposed in terms of transmitted data, of data representativeness, of influence of detection technology on the delivered dose, of evolution of diagnosis reference level. With the same approach, the next parts address scanography examinations and nuclear medicine

  2. Relevance of biotic pathways to the long-term regulation of nuclear-waste disposal. Topical report on reference western arid low-level sites

    International Nuclear Information System (INIS)

    McKenzie, D.H.; Cadwell, L.L.; Eberhardt, L.E.; Kennedy, W.E. Jr.; Peloquin, R.A.; Simmons, M.A.

    1982-10-01

    The purpose of the work reported here was to develop an order of magnitude estimate for the potential dose to man resulting from biotic transport mechanisms at a reference western arid low-level waste site. A description of the reference site is presented that includes the waste inventories, site characteristics and biological communities. Parameter values for biotic transport processes are based on data reported in current literature. Transport and exposure scenarios are developed for assessing biotic transport during 100 years following site closure. Calculations of radionuclide decay and waste container decomposition are made to estimate the quantities available for biotic transport. Dose to a man occupying the reference site following the 100 years of biotic transport are calculated. These dose estimates are compared to dose estimates for the intruder-agricultural scenario reported in the DEIS for 10 CFR 61 (NRC). Dose to man estimates as a result of biotic transport are estimated to be of the same order of magnitude as the dose resulting from the more commonly evaluated human intrusion scenario. The reported lack of potential importance of biotic transport at low-level waste sites in earlier assessment studies is not confirmed by the findings presented in this report. These results indicate that biotic transport has the potential to influence low-level waste site performance. Through biotic transport, radionuclides may be moved to locations where they can enter exposure pathways to man

  3. MO-FG-CAMPUS-IeP1-03: Establishment of Provincial Diagnostic Reference Levels in Pediatric Imaging

    International Nuclear Information System (INIS)

    Tonkopi, E; O’Brien, K

    2016-01-01

    Purpose: To establish provincial diagnostic reference levels (DRLs) in pediatric general radiography and computed tomography (CT) as a tool for the optimization of exposure parameters. Methods: Patient dose survey was conducted in the only pediatric hospital in the province of Nova Scotia. The DRLs were established as the 75th percentile of patient dose distributions in different age groups. For routine radiography projections the DRLs were determined in terms of entrance surface dose (ESD) calculated from the radiation output measurements and the tube current-exposure time product (mAs) recorded for each examination. Patient thickness was measured by the technologist during the examination. The CR and DR systems, employing respectively a fixed technique and phototiming, were evaluated separately; a two-tailed Student’s t-test was used to determine the significance of differences between the means of dose distributions. The CT studies included routine head, chest, abdomen/pelvis, and chest/abdomen/pelvis. The volume CT dose index (CTDIvol) and dose-length product (DLP) values were extracted retrospectively from PACS. The correction factors based on the effective diameter of the patient were applied to the CT dosimetry metrics based on the standard phantoms. Results: The provincial DRLs were established in the following age groups: newborn, 1, 5, 10, and 15 year olds. In general radiography the DR systems demonstrated slightly lower dose than the CR for all views, however the differences were not statistically significant (p > 0.05) for all examinations. In CT the provincial DRLs were lower than the published data, except for head DLPs in all age categories. This might be due to the small patient sample size in the survey. Future work will include additional CT data collection over an extended period of time. Conclusion: Provincial DRLs were established in the dedicated children’s hospital to provide guidance for the other facilities in examinations of pediatric

  4. MO-FG-CAMPUS-IeP1-03: Establishment of Provincial Diagnostic Reference Levels in Pediatric Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Tonkopi, E [Dalhousie University (Canada); Queen Elizabeth II Health Sciences Ctr (Canada); O’Brien, K [Dalhousie University (Canada); IWK Health Centre, Halifax, NS (Canada)

    2016-06-15

    Purpose: To establish provincial diagnostic reference levels (DRLs) in pediatric general radiography and computed tomography (CT) as a tool for the optimization of exposure parameters. Methods: Patient dose survey was conducted in the only pediatric hospital in the province of Nova Scotia. The DRLs were established as the 75th percentile of patient dose distributions in different age groups. For routine radiography projections the DRLs were determined in terms of entrance surface dose (ESD) calculated from the radiation output measurements and the tube current-exposure time product (mAs) recorded for each examination. Patient thickness was measured by the technologist during the examination. The CR and DR systems, employing respectively a fixed technique and phototiming, were evaluated separately; a two-tailed Student’s t-test was used to determine the significance of differences between the means of dose distributions. The CT studies included routine head, chest, abdomen/pelvis, and chest/abdomen/pelvis. The volume CT dose index (CTDIvol) and dose-length product (DLP) values were extracted retrospectively from PACS. The correction factors based on the effective diameter of the patient were applied to the CT dosimetry metrics based on the standard phantoms. Results: The provincial DRLs were established in the following age groups: newborn, 1, 5, 10, and 15 year olds. In general radiography the DR systems demonstrated slightly lower dose than the CR for all views, however the differences were not statistically significant (p > 0.05) for all examinations. In CT the provincial DRLs were lower than the published data, except for head DLPs in all age categories. This might be due to the small patient sample size in the survey. Future work will include additional CT data collection over an extended period of time. Conclusion: Provincial DRLs were established in the dedicated children’s hospital to provide guidance for the other facilities in examinations of pediatric

  5. 2-deoxyglucose tissue levels and insulin levels following tolazamide dosing in normal and obese mice

    International Nuclear Information System (INIS)

    Skillman, C.A.; Fletcher, H.P.

    1986-01-01

    The effect of tolazamide (TZ), a sulfonylurea, on 14 C-2-deoxyglucose ( 14 C-2DG) tissue distribution and insulin levels of normal and obese mice was investigated using an in vivo physiological method. Acute doses of TZ (50 mg/kg ip) increased 14 C-2DG levels in gastrocnemius muscle and retroperitoneal fat and produced a transient elevation of insulin which most likely accounts for the increased 14 C-2DG levels in muscle and fat. The results demonstrate that the in vivo 14 C-2DG method produced results consistent with known actions of sulfonylureas on in vitro hexose assimilation in muscle and fat. Subchronic treatment (7 days) with TZ 50 mg/kg ip twice daily did not result in increased insulin-stimulated 14 C-2DG tissue levels in normal mice when compared to saline treated controls. However, insulin levels were lower in mice treated subchronically with TZ compared to saline controls suggesting an enhancement of insulin action. Viable yellow obese mice represent a model of maturity onset obesity presenting with insulin resistance. The insulin resistance of this obese strain appears to reside in the fat tissue as assessed by comparing 14 C-2DG tissue levels of obese mice with lean littermate controls. Subchronic TZ treatment had no effect on 14 C-2DG uptake in fat or muscle tissue of viable yellow obese mice and did not alter their plasma insulin levels. It appears that genetically obese viable mice may be resistant to subchronic treatment with TZ. (author)

  6. Determination of diagnostic reference levels in general radiography in Latin America

    International Nuclear Information System (INIS)

    Blanco, S.; Mora, P.; Almonte, N.; Benavente, T.; Benson, N.; Blanco, D.; Cardenas, J.; Gomez, Y. D.; Edding, O.; Escobar, C.; Fonseca, M.; Gamarra, M.; Aguilar, J. G.; Khoury, H. J.; Quintero, A. R.; Zuniga, N. R.; Zaire, E.; Nader, A.

    2013-01-01

    The International Atomic Energy Agency (IAEA) through the International Action Plan on Radiation Protection of Patients and the International Commission on Radiological Protection have for some time carried out important efforts to assure that in the medical applications of the ionising radiations, the optimisation of radiological protection of patients is fundamental, to such a point that the IAEA includes it directly as a requirement for these practices (in its International Basic Safety Standards for Protection against Ionising Radiation and for the Safety of Radiation Sources (BSS)-GSR Part 1, 2011). For this reason, among the objectives of Regional Project RLA/9/057 and Regional Project RLA/9/067, the intention was to establish the dose references in conventional radiology for Latin America, for the purposes of determining whether these doses comply with the requirements of the BSS and to tend to improve practices, in order to minimise the dose received by the patients. (authors)

  7. Determination of effective dose rate reference values in São José do Sabugi, PB, Brazil

    International Nuclear Information System (INIS)

    Medeiros, Nilson V. da S.; Santos Júnior, José A. dos; Amaral, Romilton dos S.; Santos, Josineide M. do N.; Araújo, Eduardo E.N. de; Santos Junior, Otávio P. dos; Correia, Filipe L. de B.; Silveira, Patrícia B.

    2017-01-01

    Brazil has some areas with elevated concentration of uranium and/or thorium, such as Guarapari in the State of Espírito Santo, Poços de Caldas in Minas Gerais and regions between the States of Pernambuco and Paraíba.The Seridó region, in the State of Paraiba, consists of rocks classified as pegmatites, gneisses and feldspars, with high level of uranium ores. The high levels of primordial radionuclides have been the focus of the studies performed in the area, specifically in the uranium deposit of Espinharas and some adjacent municipalities. The aim of this work was to carry out 'in situ' measurements in the city of São José do Sabugi, Paraíba. Measurements were done using a portable gamma discriminator with combined NaI (Tl) and BGO probe, coupled to a motor vehicle that allowed to monitor 520 points in the urban and rural areas of said municipality, obtaining effective dose rates ranging from 0.7 to 1.56 mSv.y -1 and averages of 0.26 mSv.y -1 and 0.87 mSv.y -1 , respectively. The results obtained for radiometry of this municipality allow to conclude that the urban and rural areas meet the criteria established by UNSCEAR for areas considered as low background radiation. With this work, reference parameters were established for radiometric characterization of the surrounding municipalities to the uranium deposit of Espinharas. (author)

  8. Determination of effective dose rate reference values in São José do Sabugi, PB, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, Nilson V. da S.; Santos Júnior, José A. dos; Amaral, Romilton dos S.; Santos, Josineide M. do N.; Araújo, Eduardo E.N. de; Santos Junior, Otávio P. dos; Correia, Filipe L. de B., E-mail: nilson.medeiros@ufpe.br, E-mail: jaraujo@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Grupo de Radioecologia; Rojas, Lino A.V., E-mail: linomarvic@gmail.com [Centro de Aplicaciones Tecnológicas y Desarrollo Nuclear, La Habana (Cuba); Silveira, Patrícia B., E-mail: pbrandao@cnen.gov.br [Centro Regional de Ciências Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2017-07-01

    Brazil has some areas with elevated concentration of uranium and/or thorium, such as Guarapari in the State of Espírito Santo, Poços de Caldas in Minas Gerais and regions between the States of Pernambuco and Paraíba.The Seridó region, in the State of Paraiba, consists of rocks classified as pegmatites, gneisses and feldspars, with high level of uranium ores. The high levels of primordial radionuclides have been the focus of the studies performed in the area, specifically in the uranium deposit of Espinharas and some adjacent municipalities. The aim of this work was to carry out 'in situ' measurements in the city of São José do Sabugi, Paraíba. Measurements were done using a portable gamma discriminator with combined NaI (Tl) and BGO probe, coupled to a motor vehicle that allowed to monitor 520 points in the urban and rural areas of said municipality, obtaining effective dose rates ranging from 0.7 to 1.56 mSv.y{sup -1} and averages of 0.26 mSv.y{sup -1}and 0.87 mSv.y{sup -1}, respectively. The results obtained for radiometry of this municipality allow to conclude that the urban and rural areas meet the criteria established by UNSCEAR for areas considered as low background radiation. With this work, reference parameters were established for radiometric characterization of the surrounding municipalities to the uranium deposit of Espinharas. (author)

  9. Pulmonary disease in cystic fibrosis: assessment with chest CT at chest radiography dose levels.

    Science.gov (United States)

    Ernst, Caroline W; Basten, Ines A; Ilsen, Bart; Buls, Nico; Van Gompel, Gert; De Wachter, Elke; Nieboer, Koenraad H; Verhelle, Filip; Malfroot, Anne; Coomans, Danny; De Maeseneer, Michel; de Mey, Johan

    2014-11-01

    To investigate a computed tomographic (CT) protocol with iterative reconstruction at conventional radiography dose levels for the assessment of structural lung abnormalities in patients with cystic fibrosis ( CF cystic fibrosis ). In this institutional review board-approved study, 38 patients with CF cystic fibrosis (age range, 6-58 years; 21 patients 18 years) underwent investigative CT (at minimal exposure settings combined with iterative reconstruction) as a replacement of yearly follow-up posteroanterior chest radiography. Verbal informed consent was obtained from all patients or their parents. CT images were randomized and rated independently by two radiologists with use of the Bhalla scoring system. In addition, mosaic perfusion was evaluated. As reference, the previous available conventional chest CT scan was used. Differences in Bhalla scores were assessed with the χ(2) test and intraclass correlation coefficients ( ICC intraclass correlation coefficient s). Radiation doses for CT and radiography were assessed for adults (>18 years) and children (chest CT protocol can replace the two yearly follow-up chest radiographic examinations without major dose penalty and with similar diagnostic quality compared with conventional CT.

  10. Critical analysis of dose reduction trends with special reference to procedures involved in fluoroscopy

    International Nuclear Information System (INIS)

    Anderson, K.; Mattsson, O.

    1985-01-01

    Experiences of a half-year's use of dose-checking instrumentation in fluoroscopy are presented. Radiologists under training succeeded in lowering the patient dose surprisingly well - the diagnostic results remaining unchanged or even improving, because of higher image quality as a result of better diaphragming. Other factors involved in fluoroscopy are discussed. Present systems with heavy bulky intensifiers create problems for close patient contact and for the necessary manipulation, patient adjustment and application of compression. The examination will be simplified and facilitated by the use of a flat image system: proper adjustments need fewer fluoroscopic observations, and patient dose as well as examination time can be saved. Flat display principles will take over the function of the present old-fashioned intensifiers and monitors, either as single units or equipped with TV, video or digital processing accessories. A flat image system, the 'PET-scope', was tested and found to be very convenient for fluoroscopic procedures. The physical properties were studied thoroughly - the high intensification particularly gives these systems an advantage in dose reduction. New applications are possible with these light-weight low-dose units. Fluoroscopy represents a field where considerable contributions to the 'Quality Assurance' trend can be obtained. (author)

  11. Environmental policy. Ambient radioactivity levels and radiation doses in 1996

    International Nuclear Information System (INIS)

    1997-10-01

    The report is intended as information for the German Bundestag and Bundesrat as well as for the general population interested in issues of radiological protection. The information presented in the report shows that in 1996, the radiation dose to the population was low and amounted to an average of 4 millisievert (mSv), with 60% contributed by natural radiation sources, and 40% by artificial sources. The major natural source was the radioactive gas radon in buildings. Anthropogenic radiation exposure almost exclusively resulted from application of radioactive substances and ionizing radiation in the medical field, for diagnostic purposes. There still is a potential for reducing radiation doses due to these applications. In the reporting year, there were 340 000 persons occupationally exposed to ionizing radiation. Only 15% of these received a dose different from zero, the average dose was 1.8 mSv. The data show that the anthropogenic radiation exposure emanating from the uses of atomic energy or applications of ionizing radiation in technology is very low. (orig./CB) [de

  12. Analysis of data relative to the update of diagnosis reference levels in radiology and nuclear medicine. Situation 2004-2006

    International Nuclear Information System (INIS)

    2008-01-01

    This report presents the results of the analysis of patients dosimetry data the radiology and nuclear medicine institutions have to transmit yearly to I.R.S.N. in application of the 12. february decree disposal relative to the diagnosis reference levels in radiology and nuclear medicine. The analysed dosimetry data concern the evaluations realised between the date of decree publication, the 16. march 2004 and 31. december 2006. The so considered results have to allow to the Nuclear Safety Authority to define the evolution needs of the regulation. Particularly, the analysis of delivered doses in radiology and the activities given in nuclear medicine lead to propositions on the possible update of reference values of some examination types. (N.C.)

  13. Pediatric chest HRCT using the iDose4 Hybrid Iterative Reconstruction Algorithm: Which iDose level to choose?

    International Nuclear Information System (INIS)

    Smarda, M; Alexopoulou, E; Mazioti, A; Kordolaimi, S; Ploussi, A; Efstathopoulos, E; Priftis, K

    2015-01-01

    Purpose of the study is to determine the appropriate iterative reconstruction (IR) algorithm level that combines image quality and diagnostic confidence, for pediatric patients undergoing high-resolution computed tomography (HRCT). During the last 2 years, a total number of 20 children up to 10 years old with a clinical presentation of chronic bronchitis underwent HRCT in our department's 64-detector row CT scanner using the iDose IR algorithm, with almost similar image settings (80kVp, 40-50 mAs). CT images were reconstructed with all iDose levels (level 1 to 7) as well as with filtered-back projection (FBP) algorithm. Subjective image quality was evaluated by 2 experienced radiologists in terms of image noise, sharpness, contrast and diagnostic acceptability using a 5-point scale (1=excellent image, 5=non-acceptable image). Artifacts existance was also pointed out. All mean scores from both radiologists corresponded to satisfactory image quality (score ≤3), even with the FBP algorithm use. Almost excellent (score <2) overall image quality was achieved with iDose levels 5 to 7, but oversmoothing artifacts appearing with iDose levels 6 and 7 affected the diagnostic confidence. In conclusion, the use of iDose level 5 enables almost excellent image quality without considerable artifacts affecting the diagnosis. Further evaluation is needed in order to draw more precise conclusions. (paper)

  14. Reference methodologies and datasets of ICRP Committee 2 on doses from radiation exposure

    International Nuclear Information System (INIS)

    Berkovskyvl, V.; Harrison, J.D.

    2018-01-01

    A quantitative characterisation of exposures is a core element of the ICRP system of protection of people and the environment from harmful effects of ionizing radiation. Such prospective and retrospective characterisations, or 'dose assessments', are required by international and national safety standards for public, occupational and medical exposures that can occur in various exposure situations

  15. Relevance of biotic pathways to the long-term regulation of nuclear waste disposal. Topical report on reference eastern humid low-level sites

    International Nuclear Information System (INIS)

    McKenzie, D.H.; Cadwell, L.L.; Eberhardt, L.E.; Kennedy, W.E. Jr.; Peloquin, R.A.; Simmons, M.A.

    1983-01-01

    The purpose of the work reported here was to develop an order-of-magnitude estimate for the potential dose to man resulting from biotic transport mechanisms at a humid reference low-level waste site in the eastern US. A description of the reference site is presented that includes the waste inventories, site characteristics and biological communites. Parameter values for biotic transport processes are based on data reported in current literature. Transport and exposure scenarios are developed for assessing biotic transport during 500 years following site closure. Calculations of radionuclide decay and waste container decomposition are made to estimate the quantities available for biotic transport. Doses to man are calculated for the biological transport of radionucludes at the reference site after loss of institutional control. These dose estimates are compared to dose estimates we calculated for the intruder-agricultural scenarios reported in the DEIS for 10 CFR 61 (NRC). Dose to man estimates as a result of cumulative biotic transport are calculated to be of the same order-of-magnitude as the dose resulting from the more commonly evaluated human intrusion scenario. The reported lack of potential importance of biotic transport at low-level waste sites in earlier assessment studies is not confirmed by findings presented in this report. Through biotic transport, radionuclides can be moved to locations where they can enter exposure pathways to man

  16. Calculated organ doses using Monte Carlo simulations in a reference male phantom undergoing HDR brachytherapy applied to localized prostate carcinoma

    International Nuclear Information System (INIS)

    Candela-Juan, Cristian; Perez-Calatayud, Jose; Ballester, Facundo; Rivard, Mark J.

    2013-01-01

    Purpose: The aim of this study was to obtain equivalent doses in radiosensitive organs (aside from the bladder and rectum) when applying high-dose-rate (HDR) brachytherapy to a localized prostate carcinoma using 60 Co or 192 Ir sources. These data are compared with results in a water phantom and with expected values in an infinite water medium. A comparison with reported values from proton therapy and intensity-modulated radiation therapy (IMRT) is also provided. Methods: Monte Carlo simulations in Geant4 were performed using a voxelized phantom described in International Commission on Radiological Protection (ICRP) Publication 110, which reproduces masses and shapes from an adult reference man defined in ICRP Publication 89. Point sources of 60 Co or 192 Ir with photon energy spectra corresponding to those exiting their capsules were placed in the center of the prostate, and equivalent doses per clinical absorbed dose in this target organ were obtained in several radiosensitive organs. Values were corrected to account for clinical circumstances with the source located at various positions with differing dwell times throughout the prostate. This was repeated for a homogeneous water phantom. Results: For the nearest organs considered (bladder, rectum, testes, small intestine, and colon), equivalent doses given by 60 Co source were smaller (8%–19%) than from 192 Ir. However, as the distance increases, the more penetrating gamma rays produced by 60 Co deliver higher organ equivalent doses. The overall result is that effective dose per clinical absorbed dose from a 60 Co source (11.1 mSv/Gy) is lower than from a 192 Ir source (13.2 mSv/Gy). On the other hand, equivalent doses were the same in the tissue and the homogeneous water phantom for those soft tissues closer to the prostate than about 30 cm. As the distance increased, the differences of photoelectric effect in water and soft tissue, and appearance of other materials such as air, bone, or lungs, produced

  17. Bioequivalence of fixed-dose combination Myrin®-P Forte and reference drugs in loose combination.

    Science.gov (United States)

    Wang, H F; Wang, R; O'Gorman, M; Crownover, P; Naqvi, A; Jafri, I

    2013-12-01

    Myrin®-P Forte is a fixed-dose combination (FDC) tablet containing rifampicin (RMP, 150 mg), isoniazid (INH, 75 mg), ethambutol (EMB) hydrochloride (275 mg) and pyrazinamide (PZA, 400 mg) developed for the treatment of tuberculosis (TB). This study was conducted at a single centre--the Pfizer Clinical Research Unit in Singapore. To demonstrate the bioequivalence of each drug component of the Myrin-P Forte FDC and the individual product in loose combination. In a randomized, open-label, single-dose, two-way, crossover study, subjects received single doses of Myrin-P Forte or four individual products under fasting conditions in a crossover fashion with at least 7 days washout between doses. The primary measures for comparison were peak plasma concentration (C(max)) and the area under plasma concentration-time curve (AUC). Of 36 subjects enrolled, 35 completed the study. The adjusted geometric mean ratios and 90% confidence intervals for C(max) and AUC values were completely contained within bioequivalence limits (80%, 125%) for all four drugs in both formulations. Both treatments were generally well tolerated in the study. The Myrin-P Forte FDC tablet formulation is bioequivalent to the four single-drug references for RMP, INH, EMB hydrochloride and PZA at equivalent doses.

  18. Calculation of normalised organ and effective doses to adult reference computational phantoms from contemporary computed tomography scanners

    International Nuclear Information System (INIS)

    Jansen, Jan T.M.; Shrimpton, Paul C.

    2010-01-01

    The general-purpose Monte Carlo radiation transport code MCNPX has been used to simulate photon transport and energy deposition in anthropomorphic phantoms due to the x-ray exposure from the Philips iCT 256 and Siemens Definition CT scanners, together with the previously studied General Electric 9800. The MCNPX code was compiled with the Intel FORTRAN compiler and run on a Linux PC cluster. A patch has been successfully applied to reduce computing times by about 4%. The International Commission on Radiological Protection (ICRP) has recently published the Adult Male (AM) and Adult Female (AF) reference computational voxel phantoms as successors to the Medical Internal Radiation Dose (MIRD) stylised hermaphrodite mathematical phantoms that form the basis for the widely-used ImPACT CT dosimetry tool. Comparisons of normalised organ and effective doses calculated for a range of scanner operating conditions have demonstrated significant differences in results (in excess of 30%) between the voxel and mathematical phantoms as a result of variations in anatomy. These analyses illustrate the significant influence of choice of phantom on normalised organ doses and the need for standardisation to facilitate comparisons of dose. Further such dose simulations are needed in order to update the ImPACT CT Patient Dosimetry spreadsheet for contemporary CT practice. (author)

  19. Nordic working group for medical x-ray diagnostics: Diagnostic reference levels within xray diagnostics - experiences in the Nordic countries

    International Nuclear Information System (INIS)

    Leitz, W.; Groen, P.; Servomaa, A.; Einarsson, G.; Olerud, H.

    2003-01-01

    Medical x-ray diagnostics is one of the few applications of ionising radiation where people are irradiated on purpose. The strategy for radiation protection is also different compared to that in other areas that have the zero-alternative as its ultimate goal, meaning that no human beings at all are exposed in these practices. The focus in x-ray diagnostics concerning radiation protection is justification and optimisation. Optimisation implies that the examination is performed in such a way that the radiation dose is as small as possible without jeopardising the diagnostic security. X- ray diagnostics is a complex method where many technical parameters and methodology factors together are interacting in the determination of radiation dose and image quality. The optimisation process is not a simple and uncomplicated procedure, this difficulty is reflected in many international and national surveys showing a large spread of patient doses for one and the same type of examination. The concept diagnostic reference levels (DRL) has been introduced as a tool for reducing this wide distribution that is obviously indicating a lack of optimisation, and for cutting the highest radiation doses. In this presentation the concept for DRL and the experience gained in the Nordic countries with DRL are described. (orig.)

  20. Use of the mini C-arm for wrist fractures - Establishing a diagnostic reference level

    International Nuclear Information System (INIS)

    Love, G. J.; Pillai, A.; Gibson, S.

    2008-01-01

    The establishment of diagnostic reference levels (DRLs) for all typical radiological examinations became mandatory following the implementation of the Ionising Radiations (Medical Exposure) Regulations Act 2000. At present, there are no national dosage guidelines in the UK regarding use of fluoroscopy in orthopaedic trauma. The increasing popularity of the mini C-arm image intensifier amongst surgeons has led to concerns regarding use of ionizing radiation by personnel who have not been trained in radiation protection. It is therefore essential to have formal protocols for use of the mini C-arm to comply with the law and to maintain safe clinical practice. It is attempted to provide dose data for wrist fracture manipulations that may be used as a basis for setting a DRL for this procedure. Screening times were recorded for 80 wrist manipulations in a fracture clinic setting using a mini C-arm image intensifier. A DRL was set using the third quartile value for screening time. The median screening time for wrist fractures was 20 s with a range from 1 to 177 s. The third quartile value for screening time was 34 s. This value can be used as a provisional DRL for wrist fracture manipulations. The DRL is a quantitative guide for the optimisation of radiological protection. IR(ME)R 2000 states that if it is consistently exceeded by an individual operator or a piece of equipment, investigation and remedial action must be taken. We recommend that trauma units establish their own local DRLs for common procedures as made mandatory by legislation. (authors)

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

    Science.gov (United States)

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

    2017-01-01

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

  2. Studies on chronic effects of lower dose level irradiation

    International Nuclear Information System (INIS)

    Yun, T.G.; Yun, Y.S.; Yun, M.S.

    1980-01-01

    This experiment is being carried out to elucidate the chronic effects of Co 60 (γ-ray) - low doses irradiation on JCR mice at 3rd week, 6th week, and 5th month after their birth. Experimental mice at 3rd week of age have been irradiated with Co 60 - 60mR weekly, Co 60 - 500mR weekly and Co 60 - 61R biweekly at the dose rate of 60mR per second for 23 weeks until now. Co 60 - 61R irradiated mice were subdivided into Co 60 - alone group and Co 60 combined with red ginseng extracts group. In their survivor's rate and their body weight etc., no significant differences between control groups and test groups in these experimental mice. Experimented mice at 6 weeks and 5 months of age are also being irradiated with Co 60 in the same doses as the above for 14 weeks and 8 weeks until present. In these experimental groups, there are also no significant differences between control groups and experimental groups in their survivor's rate and their body weight

  3. Sci-Thur PM – Colourful Interactions: Highlights 07: Canadian Computed Tomography Survey: National Diagnostic Reference Levels

    Energy Technology Data Exchange (ETDEWEB)

    Wardlaw, Graeme M; Martel, Narine [Consumer & Clinical Radiation Protection Bureau / Health Canada (Canada)

    2016-08-15

    Purpose: The Canadian Computed (CT) Tomography Survey sought to collect CT technology and dose index data (CTDI and DLP) at the national level in order to establish national diagnostic reference levels (DRLs) for seven common CT examinations of standard-sized adults and pediatric patients. Methods: A single survey booklet (consisting of four sections) was mailed to and completed for each participating CT scanner. Survey sections collected data on (i) General facility and scanner information, (ii) routine protocols (as available), (iii) individual patient data (as applied) and (iv) manual CTDI measurements. Results: Dose index (CTDIvol and DLP) and associated patient data from 24 280 individual patient exam sequences was analyzed for seven common CT examinations performed in Canada: Adult Head, Chest, Abdomen/Pelvis, and Chest/Abdomen/Pelvis, and Pediatric Head, Chest, and Abdomen. Pediatric examination data was sub-divided into three age ranges: 0–3, 3–7 and 7–13 years. DRLs (75th percentile of dose index distributions) were found for all thirteen groups. Further analysis also permitted segmentation of examination data into 8 sub-groups, whose dose index data was displayed along with group histograms – showing relative contribution of axial vs. helical, contrast use (C+ vs. C-), and application of fixed current vs. dose reduction (DR) – 75th percentiles of DR sub-groups were, in almost all cases, lower than whole group (examination) DRLs. Conclusions: The analysis and summaries presented in the pending survey report can serve to aid local CT imaging optimization efforts within Canada and also contribute further to international efforts in radiation protection of patients.

  4. Reference levels for assays in opened installations of industrial radiography; Niveis de referencia para ensaios em instalacoes abertas de radiografia industrial

    Energy Technology Data Exchange (ETDEWEB)

    Leocadio, Joao C.; Tauhata, Luiz [Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil); Crispim, Verginia R. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear

    2001-07-01

    This work had as objectives to analyze the facilities open of industrial x-ray to obtain the distribution of doses in the operators and present proposed for the reference levels. The results of the monitoring revealed an improvement of the radiation protection conditions in the facilities and that the risk of potential exposure was reduced. The advantage of the proposed reference levels is that the supervisors would enlarge the frequency of audits in the facilities opened to accomplish the investigations and interventions.The facilities open with 'bunkers' presented distributions with 95% of the doses below 0,2 mSv and the distributions of the facilities with cordoned area they had 75% of the doses below 0,4 mSv. (author)

  5. Low-level lasers alter mRNA levels from traditional reference genes used in breast cancer cells

    Science.gov (United States)

    Teixeira, A. F.; Canuto, K. S.; Rodrigues, J. A.; Fonseca, A. S.; Mencalha, A. L.

    2017-07-01

    Cancer is among the leading causes of mortality worldwide, increasing the importance of treatment development. Low-level lasers are used in several diseases, but some concerns remains on cancers. Reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) is a technique used to understand cellular behavior through quantification of mRNA levels. Output data from target genes are commonly relative to a reference that cannot vary according to treatment. This study evaluated reference genes levels from MDA-MB-231 cells exposed to red or infrared lasers at different fluences. Cultures were exposed to red and infrared lasers, incubated (4 h, 37 °C), total RNA was extracted and cDNA synthesis was performed to evaluate mRNA levels from ACTB, GUSB and TRFC genes by RT-qPCR. Specific amplification was verified by melting curves and agarose gel electrophoresis. RefFinder enabled data analysis by geNorm, NormFinder and BestKeeper. Specific amplifications were obtained and, although mRNA levels from ACTB, GUSB or TRFC genes presented no significant variation through traditional statistical analysis, Excel-based tools revealed that the use of these reference genes are dependent of laser characteristics. Our data showed that exposure to low-level red and infrared lasers at different fluences alter the mRNA levels from ACTB, GUSB and TRFC in MDA-MB-231 cells.

  6. INFLUENCE OF HIGH CORTISOL DOSES UPON THE SERUM IMMUNOGLOBULIN LEVEL

    OpenAIRE

    Voja Pavlovic; Zoran Pavlovic

    2001-01-01

    The effects of Cortisol upon the serum immunoglobulin concentration areexamined. The experiment involved male guinea pigs of the body weight from 300 to400 g that were nonnally fed and lived under the common laboratory conditions. Theguinea pigs were divided into an experimental and a control group. The experimentalgroup's guinea pigs were given every day (in a 6 days' period) a subcutaneous dose of80 g of corti sol/kg/per day, while the control group ones were given only one ml ofthe physiol...

  7. Adaptation of penelope Monte Carlo code system to the absorbed dose metrology: characterization of high energy photon beams and calculations of reference dosimeter correction factors

    International Nuclear Information System (INIS)

    Mazurier, J.

    1999-01-01

    This thesis has been performed in the framework of national reference setting-up for absorbed dose in water and high energy photon beam provided with the SATURNE-43 medical accelerator of the BNM-LPRI (acronym for National Bureau of Metrology and Primary standard laboratory of ionising radiation). The aim of this work has been to develop and validate different user codes, based on PENELOPE Monte Carlo code system, to determine the photon beam characteristics and calculate the correction factors of reference dosimeters such as Fricke dosimeters and graphite calorimeter. In the first step, the developed user codes have permitted the influence study of different components constituting the irradiation head. Variance reduction techniques have been used to reduce the calculation time. The phase space has been calculated for 6, 12 and 25 MV at the output surface level of the accelerator head, then used for calculating energy spectra and dose distributions in the reference water phantom. Results obtained have been compared with experimental measurements. The second step has been devoted to develop an user code allowing calculation correction factors associated with both BNM-LPRI's graphite and Fricke dosimeters thanks to a correlated sampling method starting with energy spectra obtained in the first step. Then the calculated correction factors have been compared with experimental and calculated results obtained with the Monte Carlo EGS4 code system. The good agreement, between experimental and calculated results, leads to validate simulations performed with the PENELOPE code system. (author)

  8. Studies on the chronic effect of lower dose level irradiation

    International Nuclear Information System (INIS)

    Yun, T.G.; Yun, E.S.; Chung, I.Y.; Yun, M.S.; Chae, H.S.; Lee, J.Y.

    1982-01-01

    This experiment was carried out to evaluate the chronic hazard of Co-60 low dose radiation on ICR mice. There is now considerable evidence from human studies that age, both at exposure to radiation and at observation for risk, can be major determinant of radiation induced cancer risk. For this reason, ICR mice at different ages such as below were exposed to 60m rads/week, 500m rads/week and 60 rads/biweek whole body Co-60 radiation at a dose rate of 3.6 rads/min. ICR mice were irradiated during pregnant period, from 1st week to 3rd week, from 3rd week to 52nd week, from 6th week to 52nd week, and from 22nd week to 52nd week after the birth. All experimental mice were autopsied immediately after being sacrificed at 52nd week. All major organs were examined grossly and weighed. After fixation histo-pathological preparations were made for microscopical study. Blood cells W.B.C., R.B.C., Hb-from eye's vein were counted by hemocytometer and hemometer. (Author)

  9. Comparing climate and cost impacts of reference levels for reducing emissions from deforestation

    Energy Technology Data Exchange (ETDEWEB)

    Busch, Jonah [Center for Applied Biodiversity Science, Conservation International, 2011 Crystal Drive, Suite 500, Arlington, VA (United States); Strassburg, Bernardo [Center for Social and Economic Research on the Global Environment, University of East Anglia, Norwich NR4 7TJ (United Kingdom); Cattaneo, Andrea [Woods Hole Research Center, 149 Woods Hole Road, Falmouth, MA 02540-1644 (United States); Lubowski, Ruben [Environmental Defense Fund, 1875 Connecticut Avenue NW, Washington, DC (United States); Bruner, Aaron; Rice, Richard; Boltz, Frederick [Conservation International, 2011 Crystal Drive, Suite 500, Arlington, VA (United States); Creed, Anna; Ashton, Ralph, E-mail: jbusch@conservation.or [Terrestrial Carbon Group, 900 17th Street NW, Suite 700, Washington, DC (United States)

    2009-10-15

    The climate benefit and economic cost of an international mechanism for reducing emissions from deforestation and degradation (REDD) will depend on the design of reference levels for crediting emission reductions. We compare the impacts of six proposed reference level designs on emission reduction levels and on cost per emission reduction using a stylized partial equilibrium model (the open source impacts of REDD incentives spreadsheet; OSIRIS). The model explicitly incorporates national incentives to participate in an international REDD mechanism as well as international leakage of deforestation emissions. Our results show that a REDD mechanism can provide cost-efficient climate change mitigation benefits under a broad range of reference level designs. We find that the most effective reference level designs balance incentives to reduce historically high deforestation emissions with incentives to maintain historically low deforestation emissions. Estimates of emission reductions under REDD depend critically on the degree to which demand for tropical frontier agriculture generates leakage. This underscores the potential importance to REDD of complementary strategies to supply agricultural needs outside of the forest frontier.

  10. Comparing climate and cost impacts of reference levels for reducing emissions from deforestation

    International Nuclear Information System (INIS)

    Busch, Jonah; Strassburg, Bernardo; Cattaneo, Andrea; Lubowski, Ruben; Bruner, Aaron; Rice, Richard; Boltz, Frederick; Creed, Anna; Ashton, Ralph

    2009-01-01

    The climate benefit and economic cost of an international mechanism for reducing emissions from deforestation and degradation (REDD) will depend on the design of reference levels for crediting emission reductions. We compare the impacts of six proposed reference level designs on emission reduction levels and on cost per emission reduction using a stylized partial equilibrium model (the open source impacts of REDD incentives spreadsheet; OSIRIS). The model explicitly incorporates national incentives to participate in an international REDD mechanism as well as international leakage of deforestation emissions. Our results show that a REDD mechanism can provide cost-efficient climate change mitigation benefits under a broad range of reference level designs. We find that the most effective reference level designs balance incentives to reduce historically high deforestation emissions with incentives to maintain historically low deforestation emissions. Estimates of emission reductions under REDD depend critically on the degree to which demand for tropical frontier agriculture generates leakage. This underscores the potential importance to REDD of complementary strategies to supply agricultural needs outside of the forest frontier.

  11. TH-A-9A-01: Active Optical Flow Model: Predicting Voxel-Level Dose Prediction in Spine SBRT

    Energy Technology Data Exchange (ETDEWEB)

    Liu, J; Wu, Q.J.; Yin, F; Kirkpatrick, J; Cabrera, A [Duke University Medical Center, Durham, NC (United States); Ge, Y [University of North Carolina at Charlotte, Charlotte, NC (United States)

    2014-06-15

    Purpose: To predict voxel-level dose distribution and enable effective evaluation of cord dose sparing in spine SBRT. Methods: We present an active optical flow model (AOFM) to statistically describe cord dose variations and train a predictive model to represent correlations between AOFM and PTV contours. Thirty clinically accepted spine SBRT plans are evenly divided into training and testing datasets. The development of predictive model consists of 1) collecting a sequence of dose maps including PTV and OAR (spinal cord) as well as a set of associated PTV contours adjacent to OAR from the training dataset, 2) classifying data into five groups based on PTV's locations relative to OAR, two “Top”s, “Left”, “Right”, and “Bottom”, 3) randomly selecting a dose map as the reference in each group and applying rigid registration and optical flow deformation to match all other maps to the reference, 4) building AOFM by importing optical flow vectors and dose values into the principal component analysis (PCA), 5) applying another PCA to features of PTV and OAR contours to generate an active shape model (ASM), and 6) computing a linear regression model of correlations between AOFM and ASM.When predicting dose distribution of a new case in the testing dataset, the PTV is first assigned to a group based on its contour characteristics. Contour features are then transformed into ASM's principal coordinates of the selected group. Finally, voxel-level dose distribution is determined by mapping from the ASM space to the AOFM space using the predictive model. Results: The DVHs predicted by the AOFM-based model and those in clinical plans are comparable in training and testing datasets. At 2% volume the dose difference between predicted and clinical plans is 4.2±4.4% and 3.3±3.5% in the training and testing datasets, respectively. Conclusion: The AOFM is effective in predicting voxel-level dose distribution for spine SBRT. Partially supported by NIH

  12. TH-A-9A-01: Active Optical Flow Model: Predicting Voxel-Level Dose Prediction in Spine SBRT

    International Nuclear Information System (INIS)

    Liu, J; Wu, Q.J.; Yin, F; Kirkpatrick, J; Cabrera, A; Ge, Y

    2014-01-01

    Purpose: To predict voxel-level dose distribution and enable effective evaluation of cord dose sparing in spine SBRT. Methods: We present an active optical flow model (AOFM) to statistically describe cord dose variations and train a predictive model to represent correlations between AOFM and PTV contours. Thirty clinically accepted spine SBRT plans are evenly divided into training and testing datasets. The development of predictive model consists of 1) collecting a sequence of dose maps including PTV and OAR (spinal cord) as well as a set of associated PTV contours adjacent to OAR from the training dataset, 2) classifying data into five groups based on PTV's locations relative to OAR, two “Top”s, “Left”, “Right”, and “Bottom”, 3) randomly selecting a dose map as the reference in each group and applying rigid registration and optical flow deformation to match all other maps to the reference, 4) building AOFM by importing optical flow vectors and dose values into the principal component analysis (PCA), 5) applying another PCA to features of PTV and OAR contours to generate an active shape model (ASM), and 6) computing a linear regression model of correlations between AOFM and ASM.When predicting dose distribution of a new case in the testing dataset, the PTV is first assigned to a group based on its contour characteristics. Contour features are then transformed into ASM's principal coordinates of the selected group. Finally, voxel-level dose distribution is determined by mapping from the ASM space to the AOFM space using the predictive model. Results: The DVHs predicted by the AOFM-based model and those in clinical plans are comparable in training and testing datasets. At 2% volume the dose difference between predicted and clinical plans is 4.2±4.4% and 3.3±3.5% in the training and testing datasets, respectively. Conclusion: The AOFM is effective in predicting voxel-level dose distribution for spine SBRT. Partially supported by NIH

  13. Dose-response relationships and threshold levels in skin and respiratory allergy

    NARCIS (Netherlands)

    Arts, J.H.E.; Mommers, C.; Heer, C.de

    2006-01-01

    A literature study was performed to evaluate dose-response relationships and no-effect levels for sensitization and elicitation in skin- and respiratory allergy. With respect to the skin, dose-response relationships and no-effect levels were found for both intradermal and topical induction, as well

  14. Reference computations of public dose and cancer risk from airborne releases of plutonium. Nuclear safety technical report

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, V.L.

    1993-12-23

    This report presents results of computations of doses and the associated health risks of postulated accidental atmospheric releases from the Rocky Flats Plant (RFP) of one gram of weapons-grade plutonium in a form that is respirable. These computations are intended to be reference computations that can be used to evaluate a variety of accident scenarios by scaling the dose and health risk results presented here according to the amount of plutonium postulated to be released, instead of repeating the computations for each scenario. The MACCS2 code has been used as the basis of these computations. The basis and capabilities of MACCS2 are summarized, the parameters used in the evaluations are discussed, and results are presented for the doses and health risks to the public, both the Maximum Offsite Individual (a maximally exposed individual at or beyond the plant boundaries) and the population within 50 miles of RFP. A number of different weather scenarios are evaluated, including constant weather conditions and observed weather for 1990, 1991, and 1992. The isotopic mix of weapons-grade plutonium will change as it ages, the {sup 241}Pu decaying into {sup 241}Am. The {sup 241}Am reaches a peak concentration after about 72 years. The doses to the bone surface, liver, and whole body will increase slightly but the dose to the lungs will decrease slightly. The overall cancer risk will show almost no change over this period. This change in cancer risk is much smaller than the year-to-year variations in cancer risk due to weather. Finally, x/Q values are also presented for other applications, such as for hazardous chemical releases. These include the x/Q values for the MOI, for a collocated worker at 100 meters downwind of an accident site, and the x/Q value integrated over the population out to 50 miles.

  15. Saharan dust levels in Greece and received inhalation doses

    Directory of Open Access Journals (Sweden)

    C. Mitsakou

    2008-12-01

    Full Text Available The desert of Sahara is one of the major sources of mineral dust on Earth, producing around 2×108 tons/yr. Under certain weather conditions, dust particles from Saharan desert get transported over the Mediterranean Sea and most of Europe. The limiting values set by the directive EC/30/1999 of European Union can easily be exceeded by the transport of desert dust particles in the south European Region and especially in urban areas, where there is also significant contribution from anthropogenic sources. In this study, the effects of dust transport on air quality in several Greek urban areas are quantified. PM10 concentration values from stationary monitoring stations are compared to dust concentrations for the 4-year period 2003–2006. The dust concentration values in the Greek areas were estimated by the SKIRON modelling system coupled with embedded algorithms describing the dust cycle. The mean annual dust contribution to daily-averaged PM10 concentration values was found to be around or even greater than 10% in the urban areas throughout the years examined. Natural dust transport may contribute by more than 20% to the annual number of exceedances – PM10 values greater than EU limits – depending on the specific monitoring location. In a second stage of the study, the inhaled lung dose received by the residents in various Greek locations is calculated. The particle deposition efficiency of mineral dust at the different parts of the human respiratory tract is determined by applying a lung dosimetry numerical model, which incorporates inhalation dynamics and aerosol physical processes. The inhalation dose from mineral dust particles was greater in the upper respiratory system (extrathoracic region and less significant in the lungs, especially in the sensitive alveolar region. However, in cases of dust episodes, the amounts of mineral dust deposited along the human lung are comparable to those

  16. Radiation Dose Contribution To The Worker Health Level At Serpong Area

    International Nuclear Information System (INIS)

    Yuwono, Indro

    2000-01-01

    Analysis of internal and external radiation doses received for radiation and non-radiation workers of P2TBDU have been done. In the period of 1997/1998 and 1998/1999 there were no significant increasing level of radiation doses received that was 0.55 mSv and highest received radiation dose was 2.66% from dose limit value. Increasing of healthy difference on the same period was 5.76%. Increasing of healthy difference no cause by increasing of radiation dose received but maybe the food consumption design

  17. Derived reference doses for three compounds used in the photovoltaics industry: Copper indium diselenide, copper gallium diselenide, and cadmium telluride

    Energy Technology Data Exchange (ETDEWEB)

    Moskowitz, P.D.; Bernholc, N.; DePhillips, M.P.; Viren, J.

    1995-07-06

    Polycrystalline thin-film photovoltaic modules made from copper indium diselenide (CIS), copper gallium diselenide (CGS), and cadmium telluride (CdTe) arc nearing commercial development. A wide range of issues are being examined as these materials move from the laboratory to large-scale production facilities to ensure their commercial success. Issues of traditional interest include module efficiency, stability and cost. More recently, there is increased focus given to environmental, health and safety issues surrounding the commercialization of these same devices. An examination of the toxicological properties of these materials, and their chemical parents is fundamental to this discussion. Chemicals that can present large hazards to human health or the environment are regulated often more strictly than those that are less hazardous. Stricter control over how these materials are handled and disposed can increase the costs associated with the production and use of these modules dramatically. Similarly, public perception can be strongly influenced by the inherent biological hazard that these materials possess. Thus, this report: presents a brief background tutorial on how toxicological data are developed and used; overviews the toxicological data available for CIS, CGS and CdTe; develops ``reference doses`` for each of these compounds; compares the reference doses for these compounds with those of their parents; discusses the implications of these findings to photovoltaics industry.

  18. Allergen reference doses for precautionary labeling (VITAL 2.0): Clinical implications

    NARCIS (Netherlands)

    Allen, K.J.; Remington, B.C.; Baumert, J.L.; Crevel, R.W.R.; Houben, G.F.; Brooke-Taylor, S.; Kruizinga, A.G.; Taylor, S.L.

    2014-01-01

    Background There has been a dramatic proliferation of precautionary labeling by manufacturers to mitigate the perceived risk from low-level contamination from allergens in food. This has resulted in a significant reduction in choice of potentially safe foods for allergic consumers. Objectives We

  19. Radon reference levels and priority areas considering optimisation and avertable lung cancers

    International Nuclear Information System (INIS)

    Bochicchio, F.; Venoso, G.; Antignani, S.; Carpentieri, C.

    2017-01-01

    Protection from radon exposure in workplaces and dwellings, as included in the latest relevant international regulations and recommendations, is based on the new concept of 'reference level' whose meaning is significantly different from that of previous 'action level' concept. In fact, whereas remedial actions had to be considered only for radon concentrations above the action level, actions to optimise radon exposure are requested with priority above reference level but optimisation should be applied also for radon concentrations below reference level. Similar considerations can be applied to the usually called 'Rn-prone' areas, which are here proposed to be regulated as 'priority' areas. The main implication of these new challenging concepts is a substantial increase of avertable lung cancer deaths, as it will be shown using Italian data. Some practical examples of possible policy actions fitting an approach based on these new concepts will also be given, which could be useful for the implementation of the Council Directive 2013/59/Euratom. (authors)

  20. Arterial blood gas reference values for sea level and an altitude of 1,400 meters.

    Science.gov (United States)

    Crapo, R O; Jensen, R L; Hegewald, M; Tashkin, D P

    1999-11-01

    Blood gas measurements were collected on healthy lifetime nonsmokers at sea level (n = 96) and at an altitude of 1,400 meters (n = 243) to establish reference equations. At each study site, arterial blood samples were analyzed in duplicate on two separate blood gas analyzers and CO-oximeters. Arterial blood gas variables included Pa(O(2)), Pa(CO(2)), pH, and calculated alveolar-arterial PO(2) difference (AaPO(2)). CO-oximeter variables were Hb, COHb, MetHb, and Sa(O(2)). Subjects were 18 to 81 yr of age with 166 male and 173 female. Outlier data were excluded from multiple regression analysis, and reference equations were fitted to the data in two ways: (1) best fit using linear, squared, and cross-product terms; (2) simple equations, including only the variables that explained at least 3% of the variance. Two sets of equations were created: (1) using only the sea level data and (2) using the combined data with barometric pressure as an independent variable. Comparisons with earlier studies revealed small but significant differences; the decline in Pa(O(2)) with age at each altitude was consistent with most previous studies. At sea level, the equation that included barometric pressure predicted Pa(O(2)) slightly better than the sea level specific equation. The inclusion of barometric pressure in the equations allows better prediction of blood gas reference values at sea level and at altitudes as high as 1,400 meters.

  1. Advice concerning the advantages of a reference incinerator for low-level and intermediate-level radioactive waste processing

    International Nuclear Information System (INIS)

    Luyten, G.B.

    1985-05-01

    In this report, an inventory is presented of new incinerators and flue gas filters used in low and intermediate-level radioactive waste combustion. It is argued that a 'reference equipment' for the combustion of solid and liquid low- and intermediate-level wastes best meets existing Dutch radiation protection standards. A cost-benefit analysis of such an equipment is given including annual costs of investment, capital and exploration. A separate combustion process of organic liquids and carrions is considered finally. (G.J.P.)

  2. Do the UK workplace Radon Action Levels reflect the radiation dose received by the occupants?

    International Nuclear Information System (INIS)

    Denman, A.R.; Parkinson, S.; Barker, S.P.; Marley, F.; Phillips, P.S.

    1999-01-01

    In the UK, Action Levels for radon have been established at 400 Bq m -3 for the workplace and 200 Bq m -3 for the home. We have estimated the dose received by occupants of rooms with radon levels near or above the Action Level, using hourly radon readings, and a questionnaire to record occupancy. In the workplace, results for 73 staff suggest that doses are lower than expected, partly due to part-time working and partly due to the mobility of staff. The 75% quantile for the series, corrected to a 37 hour week, is 5.2 mSv at 400 Bq m -3 . Compared to the current annual limit for radiation workers, the Action Level could be increased, but the current Action Level is compatible with the recent EEC Directive requiring a lower dose limit. However, when raised radon levels in the workplace were reduced by remediation in the series we studied, the dose reduction to staff was consistently around half of the radon level reduction. Although it would be appropriate to study more locations, this suggests an Action Level for remediated workplaces of 200 Bq m -3 . Finally, in a limited series of dose assessments in domestic properties, we found that doses could considerably exceed 5 mSv at the 200 Bq m -3 Action Level, primarily because the sample included an example of high occupancy, in our case several Asian wives in purdah, whose occupancy was almost total. (author)

  3. Diagnostic accuracy at several reduced radiation dose levels for CT imaging in the diagnosis of appendicitis

    Science.gov (United States)

    Zhang, Di; Khatonabadi, Maryam; Kim, Hyun; Jude, Matilda; Zaragoza, Edward; Lee, Margaret; Patel, Maitraya; Poon, Cheryce; Douek, Michael; Andrews-Tang, Denise; Doepke, Laura; McNitt-Gray, Shawn; Cagnon, Chris; DeMarco, John; McNitt-Gray, Michael

    2012-03-01

    Purpose: While several studies have investigated the tradeoffs between radiation dose and image quality (noise) in CT imaging, the purpose of this study was to take this analysis a step further by investigating the tradeoffs between patient radiation dose (including organ dose) and diagnostic accuracy in diagnosis of appendicitis using CT. Methods: This study was IRB approved and utilized data from 20 patients who underwent clinical CT exams for indications of appendicitis. Medical record review established true diagnosis of appendicitis, with 10 positives and 10 negatives. A validated software tool used raw projection data from each scan to create simulated images at lower dose levels (70%, 50%, 30%, 20% of original). An observer study was performed with 6 radiologists reviewing each case at each dose level in random order over several sessions. Readers assessed image quality and provided confidence in their diagnosis of appendicitis, each on a 5 point scale. Liver doses at each case and each dose level were estimated using Monte Carlo simulation based methods. Results: Overall diagnostic accuracy varies across dose levels: 92%, 93%, 91%, 90% and 90% across the 100%, 70%, 50%, 30% and 20% dose levels respectively. And it is 93%, 95%, 88%, 90% and 90% across the 13.5-22mGy, 9.6-13.5mGy, 6.4-9.6mGy, 4-6.4mGy, and 2-4mGy liver dose ranges respectively. Only 4 out of 600 observations were rated "unacceptable" for image quality. Conclusion: The results from this pilot study indicate that the diagnostic accuracy does not change dramatically even at significantly reduced radiation dose.

  4. The Influence of the Terrestrial Reference Frame on Studies of Sea Level Change

    Science.gov (United States)

    Nerem, R. S.; Bar-Sever, Y. E.; Haines, B. J.; Desai, S.; Heflin, M. B.

    2015-12-01

    The terrestrial reference frame (TRF) provides the foundation for the accurate monitoring of sea level using both ground-based (tide gauges) and space-based (satellite altimetry) techniques. For the latter, tide gauges are also used to monitor drifts in the satellite instruments over time. The accuracy of the terrestrial reference frame (TRF) is thus a critical component for both types of sea level measurements. The TRF is central to the formation of geocentric sea-surface height (SSH) measurements from satellite altimeter data. The computed satellite orbits are linked to a particular TRF via the assumed locations of the ground-based tracking systems. The manner in which TRF errors are expressed in the orbit solution (and thus SSH) is not straightforward, and depends on the models of the forces underlying the satellite's motion. We discuss this relationship, and provide examples of the systematic TRF-induced errors in the altimeter derived sea-level record. The TRF is also crucial to the interpretation of tide-gauge measurements, as it enables the separation of vertical land motion from volumetric changes in the water level. TRF errors affect tide gauge measurements through GNSS estimates of the vertical land motion at each tide gauge. This talk will discuss the current accuracy of the TRF and how errors in the TRF impact both satellite altimeter and tide gauge sea level measurements. We will also discuss simulations of how the proposed Geodetic Reference Antenna in SPace (GRASP) satellite mission could reduce these errors and revolutionize how reference frames are computed in general.

  5. Decline of HIV antigen levels in cerebrospinal fluid during treatment with low-dose zidovudine

    NARCIS (Netherlands)

    de Gans, J.; Lange, J. M.; Derix, M. M.; de Wolf, F.; Eeftinck Schattenkerk, J. K.; Danner, S. A.; Ongerboer de Visser, B. W.; Cload, P.; Goudsmit, J.

    1988-01-01

    Six HIV-antigenaemic patients with AIDS or AIDS-related complex were studied to assess the effect of treatment with low-dose zidovudine (250 mg) in 6-hourly doses on HIV antigen (HIV-Ag) levels in cerebrospinal fluid (CSF). HIV-Ag was detected in CSF of three patients before treatment. These

  6. PLUTONIUM/HIGH-LEVEL VITRIFIED WASTE BDBE DOSE CALCULATION

    International Nuclear Information System (INIS)

    D.C. Richardson

    2003-01-01

    In accordance with the Nuclear Waste Policy Amendments Act of 1987, Yucca Mountain was designated as the site to be investigated as a potential repository for the disposal of high-level radioactive waste. The Yucca Mountain site is an undeveloped area located on the southwestern edge of the Nevada Test Site (NTS), about 100 miles northwest of Las Vegas. The site currently lacks rail service or an existing right-of-way. If the Yucca Mountain site is found suitable for the repository, rail service is desirable to the Office of Civilian Waste Management (OCRWM) Program because of the potential of rail transportation to reduce costs and to reduce the number of shipments relative to highway transportation. A Preliminary Rail Access Study evaluated 13 potential rail spur options. Alternative routes within the major options were also developed. Each of these options was then evaluated for potential land use conflicts and access to regional rail carriers. Three potential routes having few land use conflicts and having access to regional carriers were recommended for further investigation. Figure 1-1 shows these three routes. The Jean route is estimated to be about 120 miles long, the Carlin route to be about 365 miles long, and Caliente route to be about 365 miles long. The remaining ten routes continue to be monitored and should any of the present conflicts change, a re-evaluation of that route will be made. Complete details of the evaluation of the 13 routes can be found in the previous study. The DOE has not identified any preferred route and recognizes that the transportation issues need a full and open treatment under the National Environmental Policy Act. The issue of transportation will be included in public hearings to support development of the Environmental Impact Statement (EIS) proceedings for either the Monitored Retrievable Storage Facility or the Yucca Mountain Project or both

  7. The Dose That Works: Low Level Laser Treatment of Tendinopathy

    International Nuclear Information System (INIS)

    Tumilty, Steve; Munn, Joanne; David Baxter, G.; McDonough, Suzanne; Hurley, Deirdre A.; Basford, Jeffrey R.

    2010-01-01

    Background: Low Level Laser Therapy (LLLT) is used in the treatment of tendon injuries. However, the clinical effectiveness of this modality remains controversial with limited agreement on the most efficacious dosage and parameter choices. Purpose: To assess the clinical effectiveness of LLLT in the treatment of tendinopathy and the validity of current dosage recommendations for treatment. Method: Medical databases were searched from inception to 1st August 2008. Controlled clinical trials evaluating LLLT as a primary intervention for any tendinopathy were included in the review. Methodological quality was classified using the PEDro scale. Appropriateness of treatment parameters were assessed using established guidelines. Results: Twenty five trials met the inclusion criteria. There was conflicting findings from multiple trials: 12 showed positive effects and 13 were inconclusive or showed no effect. Dosages used in the 12 positive studies support the existence of an effective dosage window that closely resembled current guidelines. Where pooling of data was possible, LLLT showed a positive effect size; in high quality studies of lateral epicondylitis, participants' grip strength was 9.59 Kg higher than the control group; for participants with Achilles tendinopathy, the effect was 13.6 mm less pain on a 100 mm visual analogue scale. Conclusion: This study found conflicting evidence as to the effectiveness of LLLT in the treatment of tendinopathy. However, an effective dosage window emerged showing benefit in the treatment of tendinopathy. Strong evidence exists from the 12 positive studies that positive outcomes are associated with the use of current dosage recommendations for the treatment of tendinopathy.

  8. The Dose That Works: Low Level Laser Treatment of Tendinopathy

    Science.gov (United States)

    Tumilty, Steve; Munn, Joanne; McDonough, Suzanne; Hurley, Deirdre A.; Basford, Jeffrey R.; David Baxter, G.

    2010-05-01

    Background: Low Level Laser Therapy (LLLT) is used in the treatment of tendon injuries. However, the clinical effectiveness of this modality remains controversial with limited agreement on the most efficacious dosage and parameter choices. Purpose: To assess the clinical effectiveness of LLLT in the treatment of tendinopathy and the validity of current dosage recommendations for treatment. Method: Medical databases were searched from inception to 1st August 2008. Controlled clinical trials evaluating LLLT as a primary intervention for any tendinopathy were included in the review. Methodological quality was classified using the PEDro scale. Appropriateness of treatment parameters were assessed using established guidelines. Results: Twenty five trials met the inclusion criteria. There was conflicting findings from multiple trials: 12 showed positive effects and 13 were inconclusive or showed no effect. Dosages used in the 12 positive studies support the existence of an effective dosage window that closely resembled current guidelines. Where pooling of data was possible, LLLT showed a positive effect size; in high quality studies of lateral epicondylitis, participants' grip strength was 9.59 Kg higher than the control group; for participants with Achilles tendinopathy, the effect was 13.6 mm less pain on a 100 mm visual analogue scale. Conclusion: This study found conflicting evidence as to the effectiveness of LLLT in the treatment of tendinopathy. However, an effective dosage window emerged showing benefit in the treatment of tendinopathy. Strong evidence exists from the 12 positive studies that positive outcomes are associated with the use of current dosage recommendations for the treatment of tendinopathy.

  9. PLUTONIUM/HIGH-LEVEL VITRIFIED WASTE BDBE DOSE CALCULATION

    Energy Technology Data Exchange (ETDEWEB)

    D.C. Richardson

    2003-03-19

    In accordance with the Nuclear Waste Policy Amendments Act of 1987, Yucca Mountain was designated as the site to be investigated as a potential repository for the disposal of high-level radioactive waste. The Yucca Mountain site is an undeveloped area located on the southwestern edge of the Nevada Test Site (NTS), about 100 miles northwest of Las Vegas. The site currently lacks rail service or an existing right-of-way. If the Yucca Mountain site is found suitable for the repository, rail service is desirable to the Office of Civilian Waste Management (OCRWM) Program because of the potential of rail transportation to reduce costs and to reduce the number of shipments relative to highway transportation. A Preliminary Rail Access Study evaluated 13 potential rail spur options. Alternative routes within the major options were also developed. Each of these options was then evaluated for potential land use conflicts and access to regional rail carriers. Three potential routes having few land use conflicts and having access to regional carriers were recommended for further investigation. Figure 1-1 shows these three routes. The Jean route is estimated to be about 120 miles long, the Carlin route to be about 365 miles long, and Caliente route to be about 365 miles long. The remaining ten routes continue to be monitored and should any of the present conflicts change, a re-evaluation of that route will be made. Complete details of the evaluation of the 13 routes can be found in the previous study. The DOE has not identified any preferred route and recognizes that the transportation issues need a full and open treatment under the National Environmental Policy Act. The issue of transportation will be included in public hearings to support development of the Environmental Impact Statement (EIS) proceedings for either the Monitored Retrievable Storage Facility or the Yucca Mountain Project or both.

  10. Safety Study of the X-Ray Reference Laboratory for Radiation Protection Levels (IR-14D)

    International Nuclear Information System (INIS)

    Garcia, G.

    1999-01-01

    This report is a study about the safety of the X-ray reference laboratory that has been recently constructed in the building 2 of the CIEMAT. After a brief description of the apparatus, we present the method used to calculate the exposure and absorbed dose rates in the most characteristic points of the laboratory. This method takes into account the spectral distribution of the radiation beams as a function of the accelerating voltage. The built-up factors of the absorbent materials have been considered to calculate the transmission of the radiation beams through the filters and shielding. Scattered radiations has been introduced in the calculations by means of a semiempirical method. This model supposes that multiple scattering processes give an isotropic contribution to the reflected beams and the single scattered can be described in terms of the differential cross section of Klein-Nishina. The results of this study have been applied to determine the maximum dose equivalent that the personnel of the laboratory could receive in normal operation conditions. (Author) 5 refs

  11. Reference hearing threshold levels for chirp signals delivered by an ER-3A insert earphone

    DEFF Research Database (Denmark)

    Gøtsche-Rasmussen, Kristian; Poulsen, Torben; Elberling, Claus

    2012-01-01

    back from a Tucker Davies Technologies System II, and a Matlab program controlled the test setup. The results are specified in dB peak-to-peak equivalent threshold sound pressure levels (dB peETSPL). Study sample: The test group consisted of 25 otologically-normal young adults (age 18–25 years......Objective: To establish reference hearing threshold levels for chirps and frequency-specific chirps. Design: Hearing thresholds were determined monaurally for broad-band chirps and octave-band chirps using the Etymotic Research, ER-3A insert earphone. The chirps were presented using two repetition...

  12. Mercure IV code application to the external dose computation from low and medium level wastes

    International Nuclear Information System (INIS)

    Tomassini, T.

    1985-01-01

    In the present work the external dose from low and medium level wastes is calculated using MERCURE IV code. The code utilizes MONTECARLO method for integrating multigroup line of sight attenuation Kernels

  13. Patient dose, gray level and exposure index with a computed radiography system

    Science.gov (United States)

    Silva, T. R.; Yoshimura, E. M.

    2014-02-01

    Computed radiography (CR) is gradually replacing conventional screen-film system in Brazil. To assess image quality, manufactures provide the calculation of an exposure index through the acquisition software of the CR system. The objective of this study is to verify if the CR image can be used as an evaluator of patient absorbed dose too, through a relationship between the entrance skin dose and the exposure index or the gray level values obtained in the image. The CR system used for this study (Agfa model 30-X with NX acquisition software) calculates an exposure index called Log of the Median (lgM), related to the absorbed dose to the IP. The lgM value depends on the average gray level (called Scan Average Level (SAL)) of the segmented pixel value histogram of the whole image. A Rando male phantom was used to simulate a human body (chest and head), and was irradiated with an X-ray equipment, using usual radiologic techniques for chest exams. Thermoluminescent dosimeters (LiF, TLD100) were used to evaluate entrance skin dose and exit dose. The results showed a logarithm relation between entrance dose and SAL in the image center, regardless of the beam filtration. The exposure index varies linearly with the entrance dose, but the angular coefficient is beam quality dependent. We conclude that, with an adequate calibration, the CR system can be used to evaluate the patient absorbed dose.

  14. Age-specific reference values for serum FSH and estradiol levels throughout the reproductive period.

    Science.gov (United States)

    Grisendi, Valentina; Spada, Elena; Argento, Cindy; Plebani, Maddalena; Milani, Silvano; Seracchioli, Renato; Volpe, Annibale; La Marca, Antonio

    2014-06-01

    High serum day 3 FSH levels are associated with poor ovarian reserve and reduced fertility, but the interpretation of FSH values according to age is still not univocal. The purpose of this study was to determine age-dependent reference values in women with regular menstrual cycles and FSH as a guide for specialists. The study was performed at the Department of Mother-Infant of a University-based tertiary care centre. One-hundred ninety-two healthy normal menstruating women were recruited for the study. All patients attended the department on menstrual cycle day 3 for a blood sample for FSH and estradiol determination. A linear relationship between FSH or estradiol serum levels and age was observed. The FSH level increased by 0.11 IU for every year of age (1 IU for every 9 years of age). The values of FSH and estradiol corresponding to the 5th, 25th, 50th, 75th, 95th centiles for any specific age have been calculated. Serum FSH levels need to be interpreted according to age-dependent reference values. Serum FSH levels on 95th centile for any age may represent a warning sign for reduced ovarian reserve.

  15. Reference design and operations for deep borehole disposal of high-level radioactive waste

    International Nuclear Information System (INIS)

    Herrick, Courtney Grant; Brady, Patrick Vane; Pye, Steven; Arnold, Bill Walter; Finger, John Travis; Bauer, Stephen J.

    2011-01-01

    A reference design and operational procedures for the disposal of high-level radioactive waste in deep boreholes have been developed and documented. The design and operations are feasible with currently available technology and meet existing safety and anticipated regulatory requirements. Objectives of the reference design include providing a baseline for more detailed technical analyses of system performance and serving as a basis for comparing design alternatives. Numerous factors suggest that deep borehole disposal of high-level radioactive waste is inherently safe. Several lines of evidence indicate that groundwater at depths of several kilometers in continental crystalline basement rocks has long residence times and low velocity. High salinity fluids have limited potential for vertical flow because of density stratification and prevent colloidal transport of radionuclides. Geochemically reducing conditions in the deep subsurface limit the solubility and enhance the retardation of key radionuclides. A non-technical advantage that the deep borehole concept may offer over a repository concept is that of facilitating incremental construction and loading at multiple perhaps regional locations. The disposal borehole would be drilled to a depth of 5,000 m using a telescoping design and would be logged and tested prior to waste emplacement. Waste canisters would be constructed of carbon steel, sealed by welds, and connected into canister strings with high-strength connections. Waste canister strings of about 200 m length would be emplaced in the lower 2,000 m of the fully cased borehole and be separated by bridge and cement plugs. Sealing of the upper part of the borehole would be done with a series of compacted bentonite seals, cement plugs, cement seals, cement plus crushed rock backfill, and bridge plugs. Elements of the reference design meet technical requirements defined in the study. Testing and operational safety assurance requirements are also defined. Overall

  16. Reference design and operations for deep borehole disposal of high-level radioactive waste.

    Energy Technology Data Exchange (ETDEWEB)

    Herrick, Courtney Grant; Brady, Patrick Vane; Pye, Steven; Arnold, Bill Walter; Finger, John Travis; Bauer, Stephen J.

    2011-10-01

    A reference design and operational procedures for the disposal of high-level radioactive waste in deep boreholes have been developed and documented. The design and operations are feasible with currently available technology and meet existing safety and anticipated regulatory requirements. Objectives of the reference design include providing a baseline for more detailed technical analyses of system performance and serving as a basis for comparing design alternatives. Numerous factors suggest that deep borehole disposal of high-level radioactive waste is inherently safe. Several lines of evidence indicate that groundwater at depths of several kilometers in continental crystalline basement rocks has long residence times and low velocity. High salinity fluids have limited potential for vertical flow because of density stratification and prevent colloidal transport of radionuclides. Geochemically reducing conditions in the deep subsurface limit the solubility and enhance the retardation of key radionuclides. A non-technical advantage that the deep borehole concept may offer over a repository concept is that of facilitating incremental construction and loading at multiple perhaps regional locations. The disposal borehole would be drilled to a depth of 5,000 m using a telescoping design and would be logged and tested prior to waste emplacement. Waste canisters would be constructed of carbon steel, sealed by welds, and connected into canister strings with high-strength connections. Waste canister strings of about 200 m length would be emplaced in the lower 2,000 m of the fully cased borehole and be separated by bridge and cement plugs. Sealing of the upper part of the borehole would be done with a series of compacted bentonite seals, cement plugs, cement seals, cement plus crushed rock backfill, and bridge plugs. Elements of the reference design meet technical requirements defined in the study. Testing and operational safety assurance requirements are also defined. Overall

  17. Hydroxychloroquine Blood Levels in Systemic Lupus Erythematosus: Clarifying Dosing Controversies and Improving Adherence.

    Science.gov (United States)

    Durcan, Laura; Clarke, William A; Magder, Laurence S; Petri, Michelle

    2015-11-01

    Hydroxychloroquine (HCQ) is used for its effect on systemic lupus erythematosus (SLE) disease activity and longterm benefits. This can be limited by adherence. One way to assess adherence is to measure blood levels. Conflicting data exist regarding blood levels and disease activity. There is disagreement about dosing; rheumatologists recommend weight-based dosing while some other specialists advocate height-based "ideal body weight" dosing. Patients were prescribed HCQ not exceeding 6.5 mg/kg (max 400 mg/day). In hemodialysis, the dose was 200 mg after each session, and in renal insufficiency it was 200 mg/day. Levels were measured at each visit with a therapeutic range of 500-2000 ng/ml. Patients were divided according to baseline blood level. To assess the effect of measurement and counseling on adherence, we compared the proportion of patients with a level of 500 ng/ml or higher based on the number of prior assessments. The proportion of patients with HCQ levels in the therapeutic range differed significantly by age, sex, and Vitamin D level. There was a trend toward lower levels with renal failure. Blood levels were similar regardless of height and ideal body weight. Comparing those with undetectable, subtherapeutic, and therapeutic levels, disease activity decreased (SLE Disease Activity Index 2.92, 2.36, and 2.20, p = 0.04 for trend). At first, 56% were therapeutic, and by the third measurement this increased to 80% (p ≤ 0.0001). There was a trend toward higher disease activity with lower HCQ levels. Renal failure dosing led to suboptimum levels. We show that weight-based dosing (max 400 mg daily) is appropriate and that height does not appear to influence levels. Measurement, counseling, and repeated testing can increase adherence rates.

  18. Mapping of radio frequency electromagnetic field exposure levels in outdoor environment and comparing with reference levels for general public health.

    Science.gov (United States)

    Cansiz, Mustafa; Abbasov, Teymuraz; Kurt, M Bahattin; Celik, A Recai

    2018-03-01

    In this study, radio frequency electromagnetic field exposure levels were measured on the main streets in the city center of Diyarbakır, Turkey. Measured electric field levels were plotted on satellite imagery of Diyarbakır and were compared with exposure guidelines published by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Exposure measurements were performed in dense urban, urban and suburban areas each day for 7 consecutive days. The measurement system consisted of high precision and portable spectrum analyzer, three-axis electric field antenna, connection cable and a laptop which was used to record the measurement samples as a data logger. The highest exposure levels were detected for two places, which are called Diclekent and Batıkent. It was observed that the highest instantaneous electric field strength value for Batıkent was 7.18 V/m and for Diclekent was 5.81 V/m. It was statistically determined that the main contributor band to the total exposure levels was Universal Mobile Telecommunications System band. Finally, it was concluded that all measured exposure levels were lower than the reference levels recommended by ICNIRP for general public health.

  19. A simple method for conversion of airborne gamma-ray spectra to ground level doses

    DEFF Research Database (Denmark)

    Korsbech, Uffe C C; Bargholz, Kim

    1996-01-01

    A new and simple method for conversion of airborne NaI(Tl) gamma-ray spectra to dose rates at ground level has been developed. By weighting the channel count rates with the channel numbers a spectrum dose index (SDI) is calculated for each spectrum. Ground level dose rates then are determined...... by multiplying the SDI by an altitude dependent conversion factor. The conversion factors are determined from spectra based on Monte Carlo calculations. The results are compared with measurements in a laboratory calibration set-up. IT-NT-27. June 1996. 27 p....

  20. Analysis of data relative to the update of diagnostic reference levels in radiology and nuclear medicine. 2011-2012 review

    International Nuclear Information System (INIS)

    2014-01-01

    Applying the Order of 24 October 2011 on diagnostic reference levels, departments of radiology and nuclear medicine must send a sample of 'patient' dosimetric data to the IRSN each year. The results of the analysis of dosimetric data performed between the 1 January 2011 and the 31 December 2012 presented in this report should enable the authority to define the needs for updating regulations. Professional involvement in DRLs improved globally over the 2011-2012 period but is heterogeneous according to the imaging area considered. The participation of conventional radiology professionals is still low, with less than 30% against over 75% in CT and 85% in nuclear medicine. Data collection in pediatrics, considering all the fields of medical imaging, remains extremely limited. This shows almost no dose assessment for children by imaging departments, and has the effect of not allowing authorities to provide professionals with DRLs representative of pediatric practices. The analysis of radiology doses and nuclear medicine administered activities by IRSN shows an overall decrease of statistical indicators on which DRLs are indexed. These results lead to proposals for updating reference values for a large number of examinations. In addition to the analysis of data collected for examinations currently mentioned in regulatory texts, IRSN recommends to update DRLs in a more general way by changing the strategy for collecting and updating pediatric DRLs, by including interventional radiology - specialty in which the radiation protection presents a major challenge - by introducing a more ambitious indicator than the 75. percentile in conventional radiology and nuclear medicine - the 25. percentile statistical indicator, and by taking into account new technologies inducing additional exposures to the patient as CT-scan associated with the PET. (authors)

  1. Computer-aided detection (CAD) of solid pulmonary nodules in chest x-ray equivalent ultralow dose chest CT - first in-vivo results at dose levels of 0.13 mSv

    Energy Technology Data Exchange (ETDEWEB)

    Messerli, Michael, E-mail: Michael.Messerli@usz.ch [Division of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen (Switzerland); Kluckert, Thomas; Knitel, Meinhard [Division of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen (Switzerland); Rengier, Fabian [Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg (Germany); Warschkow, René [Department of Surgery, Cantonal Hospital St. Gallen (Switzerland); Alkadhi, Hatem [Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University Zurich (Switzerland); Leschka, Sebastian [Division of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen (Switzerland); Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University Zurich (Switzerland); Wildermuth, Simon; Bauer, Ralf W. [Division of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen (Switzerland)

    2016-12-15

    Highlights: • Computer-aided detection (CAD) of solid pulmonary nodules was compared in 202 patients in standard dose and ultralow dose CT. • The per–nodule sensitivity of CAD was 70% in standard dose CT and 68% in ultralow dose CT. • The per–nodule sensitivity of CAD in standard dose CT was similar to ultralow dose CT in all size subgroups (all p > 0.05). • Adding CAD markings in ultralow dose CT significantly improved the sensitivity of two radiologists from 77% to 88% and from 66% to 79%, respectively. • CAD can serve as an excellent second reader for nodule detection in CT even at dose levels similar to chest X-ray. - Abstract: Objectives: To determine the value of computer-aided detection (CAD) for solid pulmonary nodules in ultralow radiation dose single-energy computed tomography (CT) of the chest using third-generation dual-source CT at 100 kV and fixed tube current at 70 mAs with tin filtration. Methods: 202 consecutive patients undergoing clinically indicated standard dose chest CT (1.8 ± 0.7 mSv) were prospectively included and scanned with an additional ultralow dose CT (0.13 ± 0.01 mSv) in the same session. Standard of reference (SOR) was established by consensus reading of standard dose CT by two radiologists. CAD was performed in standard dose and ultralow dose CT with two different reconstruction kernels. CAD detection rate of nodules was evaluated including subgroups of different nodule sizes (<5, 5–7, >7 mm). Sensitivity was further analysed in multivariable mixed effects logistic regression. Results: The SOR included 279 solid nodules (mean diameter 4.3 ± 3.4 mm, range 1–24 mm). There was no significant difference in per–nodule sensitivity of CAD in standard dose with 70% compared to 68% in ultralow dose CT both overall and in different size subgroups (all p > 0.05). CAD led to a significant increase of sensitivity for both radiologists reading the ultralow dose CT scans (all p < 0.001). In multivariable analysis, the use

  2. Computer-aided detection (CAD) of solid pulmonary nodules in chest x-ray equivalent ultralow dose chest CT - first in-vivo results at dose levels of 0.13 mSv

    International Nuclear Information System (INIS)

    Messerli, Michael; Kluckert, Thomas; Knitel, Meinhard; Rengier, Fabian; Warschkow, René; Alkadhi, Hatem; Leschka, Sebastian; Wildermuth, Simon; Bauer, Ralf W.

    2016-01-01

    Highlights: • Computer-aided detection (CAD) of solid pulmonary nodules was compared in 202 patients in standard dose and ultralow dose CT. • The per–nodule sensitivity of CAD was 70% in standard dose CT and 68% in ultralow dose CT. • The per–nodule sensitivity of CAD in standard dose CT was similar to ultralow dose CT in all size subgroups (all p > 0.05). • Adding CAD markings in ultralow dose CT significantly improved the sensitivity of two radiologists from 77% to 88% and from 66% to 79%, respectively. • CAD can serve as an excellent second reader for nodule detection in CT even at dose levels similar to chest X-ray. - Abstract: Objectives: To determine the value of computer-aided detection (CAD) for solid pulmonary nodules in ultralow radiation dose single-energy computed tomography (CT) of the chest using third-generation dual-source CT at 100 kV and fixed tube current at 70 mAs with tin filtration. Methods: 202 consecutive patients undergoing clinically indicated standard dose chest CT (1.8 ± 0.7 mSv) were prospectively included and scanned with an additional ultralow dose CT (0.13 ± 0.01 mSv) in the same session. Standard of reference (SOR) was established by consensus reading of standard dose CT by two radiologists. CAD was performed in standard dose and ultralow dose CT with two different reconstruction kernels. CAD detection rate of nodules was evaluated including subgroups of different nodule sizes (<5, 5–7, >7 mm). Sensitivity was further analysed in multivariable mixed effects logistic regression. Results: The SOR included 279 solid nodules (mean diameter 4.3 ± 3.4 mm, range 1–24 mm). There was no significant difference in per–nodule sensitivity of CAD in standard dose with 70% compared to 68% in ultralow dose CT both overall and in different size subgroups (all p > 0.05). CAD led to a significant increase of sensitivity for both radiologists reading the ultralow dose CT scans (all p < 0.001). In multivariable analysis, the use

  3. Adaptation of penelope Monte Carlo code system to the absorbed dose metrology: characterization of high energy photon beams and calculations of reference dosimeter correction factors; Adaptation du code Monte Carlo penelope pour la metrologie de la dose absorbee: caracterisation des faisceaux de photons X de haute energie et calcul de facteurs de correction de dosimetres de reference

    Energy Technology Data Exchange (ETDEWEB)

    Mazurier, J

    1999-05-28

    This thesis has been performed in the framework of national reference setting-up for absorbed dose in water and high energy photon beam provided with the SATURNE-43 medical accelerator of the BNM-LPRI (acronym for National Bureau of Metrology and Primary standard laboratory of ionising radiation). The aim of this work has been to develop and validate different user codes, based on PENELOPE Monte Carlo code system, to determine the photon beam characteristics and calculate the correction factors of reference dosimeters such as Fricke dosimeters and graphite calorimeter. In the first step, the developed user codes have permitted the influence study of different components constituting the irradiation head. Variance reduction techniques have been used to reduce the calculation time. The phase space has been calculated for 6, 12 and 25 MV at the output surface level of the accelerator head, then used for calculating energy spectra and dose distributions in the reference water phantom. Results obtained have been compared with experimental measurements. The second step has been devoted to develop an user code allowing calculation correction factors associated with both BNM-LPRI's graphite and Fricke dosimeters thanks to a correlated sampling method starting with energy spectra obtained in the first step. Then the calculated correction factors have been compared with experimental and calculated results obtained with the Monte Carlo EGS4 code system. The good agreement, between experimental and calculated results, leads to validate simulations performed with the PENELOPE code system. (author)

  4. Intraocular levels of methotrexate after oral low-dose treatment in chronic uveitis.

    Science.gov (United States)

    Puchta, Joachim; Hattenbach, Lars-Olof; Baatz, Holger

    2005-01-01

    To determine the intraocular levels of methotrexate in low-dose treatment of noninfectious uveitis. One day after oral administration, the methotrexate level was measured in the aqueous humor and serum of a patient with noninfectious uveitis, who underwent cataract surgery. A fluorescence polarization immunoassay was used for determination. After oral administration, methotrexate was only measurable in aqueous humor but not in serum. In uveitis, orally administered low-dose methotrexate reaches detectable levels in aqueous humor, even in the absence of detectable levels in serum. Copyright (c) 2005 S. Karger AG, Basel.

  5. The Contribution of Tissue Level Organization to Genomic Stability Following Low Dose/Low Dose Rate Gamma and Proton Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Cheryl G. Burrell, Ph.D.

    2012-05-14

    The formation of functional tissue units is necessary in maintaining homeostasis within living systems, with individual cells contributing to these functional units through their three-dimensional organization with integrin and adhesion proteins to form a complex extra-cellular matrix (ECM). This is of particular importance in those tissues susceptible to radiation-induced tumor formation, such as epithelial glands. The assembly of epithelial cells of the thyroid is critical to their normal receipt of, and response to, incoming signals. Traditional tissue culture and live animals present significant challenges to radiation exposure and continuous sampling, however, the production of bioreactor-engineered tissues aims to bridge this gap by improve capabilities in continuous sampling from the same functional tissue, thereby increasing the ability to extrapolate changes induced by radiation to animals and humans in vivo. Our study proposes that the level of tissue organization will affect the induction and persistence of low dose radiation-induced genomic instability. Rat thyroid cells, grown in vitro as 3D tissue analogs in bioreactors and as 2D flask grown cultures were exposed to acute low dose (1, 5, 10 and 200 cGy) gamma rays. To assess immediate (6 hours) and delayed (up to 30 days) responses post-irradiation, various biological endpoints were studied including cytogenetic analyses, apoptosis analysis and cell viability/cytotoxicity analyses. Data assessing caspase 3/7 activity levels show that, this activity varies with time post radiation and that, overall, 3D cultures display more genomic instability (as shown by the lower levels of apoptosis over time) when compared to the 2D cultures. Variation in cell viability levels were only observed at the intermediate and late time points post radiation. Extensive analysis of chromosomal aberrations will give further insight on the whether the level of tissue organization influences genomic instability patterns after

  6. Estimation of radiological dose from radon, thoron and their progeny levels in the dwellings of Shivamogga district, Karnataka, India

    International Nuclear Information System (INIS)

    Rangaswamvi, D.R.; Sannappa, J.; Srinivasa, E.

    2018-01-01

    Among all natural radiation exposure to man, inhalation of radon, thoron and their progenies are the major contributor (50 %) to the dose from ionizing radiation received by the general population. Based on the results of epidemiological studies in Europe and North America, the World Health Organization (WHO) has recommended reducing the indoor radon reference level from 200 to 100 Bq.m -3 . In view of this, focus has now been given for simultaneous measurement of radon, thoron and their progeny concentration in indoor air and also to estimate radiological dose in the dwellings of the Shivamogga district. The geology of the Shivamogga district comprises different types of rock formation such as granites, schists, magnetites and gneisses, Meta basalt, laterites, quartz and chlorite schist, Graywacke etc. Present study was concentrating more in granite bed rock regions along with their surrounding regions

  7. A comparison and cross-reference of commercial low-level radioactive waste acceptance criteria

    International Nuclear Information System (INIS)

    Kerr, T.A.

    1997-04-01

    This document, prepared by the National Low-Level Waste Management Program at the Idaho National Engineering and Environmental Laboratory, is a comparison and cross-reference of commercial low-level radioactive waste acceptance criteria. Many of these are draft or preliminary criteria as well as implemented criteria at operating low-level radioactive waste management facilities. Waste acceptance criteria from the following entities are included: US Nuclear Regulatory Commission, South Carolina, Washington, Utah, Nevada, California, illinois, Texas, North Carolina, Nebraska, Pennsylvania, New York, and the Midwest Compact Region. Criteria in the matrix include the following: physical form, chemical form, liquid limits, void space in packages, concentration averaging, types of packaging, chelating agents, solidification media, stability requirements, sorptive media, gas, oil, biological waste, pyrophorics, source material, special nuclear material, package dimensions, incinerator ash, dewatered resin, transuranics, and mixed waste. Each criterion in the matrix is cross-referenced to its source document so that exact requirements can be determined

  8. Diagnostic reference levels in intraoral radiology: From the laboratory to clinical practice

    International Nuclear Information System (INIS)

    Alcaraz, M.; Velasco, E.; Martinez-Beneyto, Y.; Velasco, F.; Parra, C.; Canteras, M.

    2010-01-01

    To determine the diagnostic reference levels (DRLs) for obtaining a diagnostic image in the normal conditions of clinical practice and to explain the differences between the levels found and the DRLs obtained in other experimental conditions, suggesting that there has been a reduction in the European Union (EU) recommended levels. A total of 2296 official reports on dental surgeries from 16 Spanish autonomous regions compiled during 2008 were studied. A mean DRL of 3.3 mGy was determined: 2.6 mGy for installations using direct digital systems, 3.4 mGy for those using indirect systems, 4.4 mGy for those using Ultra-speed film and 3.7 mGy for those using Insight. The DRLs found in this survey are below the EU recommended values but far above previously described values, possibly because all the different systems were considered and because values refer to those of the normal work conditions of clinical practice. (authors)

  9. Hydroxychloroquine Blood Levels in SLE: Clarifying dosing controversies and improving adherence

    Science.gov (United States)

    Durcan, Laura; Clarke, William A; Magder, Laurence S.; Petri, Michelle

    2015-01-01

    OBJECTIVES Hydroxychloroquine is used for its effect on systemic lupus erythematosus (SLE) disease activity and long-term benefits. This can be limited by adherence. One way to assess adherence is to measure blood levels. Conflicting data exist regarding blood levels and disease activity. There is dosing controversy; rheumatologists recommend weight-based, while ophthalmologists advocate height-based ‘ideal body weight’ dosing. METHODS Patients were prescribed hydroxychloroquine not to exceed 6.5mg/kg (max400mg/day). In hemodialysis, the dose was 200mg after each session, in renal insufficiency it was 200mg/day. Levels were measured at each visit with a therapeutic range of 500-2000 ng/ml. Patients were divided according to baseline blood level. To assess the impact of measurement and counseling on adherence, we compared the proportion of patients with a level of 500ng/ml or higher based on how many prior assessments the patient had. RESULTS The proportion of patients with hydroxychloroquine levels in the therapeutic range differed significantly by age, gender and vitamin D level. There was a trend toward lower levels with renal failure. Blood levels were similar regardless of height and ideal body weight. Comparing those with undetectable, sub-therapeutic and therapeutic levels, disease activity decreased (SLEDAI 2.92, 2.36 and 2.20)(P=0.04, for trend). At first, 56% were therapeutic and by the third measurement this increased to 80% (p =hydroxychloroquine levels. Renal failure dosing led to sub-optimum levels. We show that weight-based dosing (max 400mg daily) is appropriate and that height does not appear to influence levels. Measurement, counseling and repeated testing can increase adherences rates. PMID:26428205

  10. Levels of external natural radiation and doses to population in Heilongjiang province

    International Nuclear Information System (INIS)

    Liang Yicheng; He Yongjiang; Wang Lu

    1985-01-01

    The external natural radiation level in Heilongjiang Province was measured by using China-made FD-71 scintillation radiometers and RSS-111 high pressure ionization chambers. The doses of external radiation to population were also calculated. The population-weighted average value of the absorbed dose rate from terrestrial γ-radiation was 7.2 x 10 -8 Gy.h -1 for outdoors, and 10.8 x 10 -8 Gy.h -1 for indoors. The population-weighted average absorbed dose rate in air from cosmic rays was 3.3 x 10 -8 Gy.h -1 . The annual population-weighted average effective dose equivalent and the annual collective effective dose equivalent from the environmental γ-radiation were 620 μSv and 20.1 x 10 3 man.Sv, respectively. The corresponding figures from cosmic rays were 260 μSv and 8.7 x 10 3 man.Sv, respectively

  11. Pre-1989 epidemiological surveys of low-level dose pre-conception irradiation

    International Nuclear Information System (INIS)

    Rose, K.S.B.

    1990-01-01

    Information from 59 pre-1989 epidemiological surveys concerning pre-conception irradiation at doses less than 0.1 Gy has been collated to determine whether any consistent patterns of health effects emerge. The surveys are considered in three groups: childhood malignancies, Down's syndrome and indicators of reproductive damage. Although a pattern is observed for Down's syndrome, no reliable associations are apparent for childhood malignancies (where all surveys pre-date the Gardner survey at Sellafield) or indications of reproductive damage. The twelve surveys of Down's syndrome in relation to maternal pre-conception irradiation received for medical reasons show a pattern consistent with a doubling dose of about 20 mGy. This doubling dose value is, however, not based on individual measurements of ovarian dose and is inconsistent with results from high-level dose surveys. There is no association between paternal irradiation and Down's syndrome. (author)

  12. Technology, Safety and Costs of Decommissioning a Reference Low-Level Waste Burial Ground. Appendices

    International Nuclear Information System (INIS)

    None

    1980-01-01

    Safety and cost information are developed for the conceptual decommissioning of commercial low-level waste (LLW) burial grounds. Two generic burial grounds, one located on an arid western site and the other located on a humid eastern site, are used as reference facilities for the study. The two burial grounds are assumed to have the same site capacity for waste, the same radioactive waste inventory, and similar trench characteristics and operating procedures. The climate, geology. and hydrology of the two sites are chosen to be typical of real western and eastern sites. Volume 2 (Appendices) contains the detailed analyses and data needed to support the results given in Volume 1.

  13. Technology, Safety and Costs of Decommissioning a Reference Low-Level Waste Burial Ground. Main Report

    International Nuclear Information System (INIS)

    Murphy, E. S.; Holter, G. M.

    1980-01-01

    Safety and cost information are developed for the conceptual decommissioning of commercial low-level waste (LLW) burial grounds. Two generic burial grounds, one located on an arid western site and the other located on a humid eastern site, are used as reference facilities for the study. The two burial grounds are assumed to have the same site capacity for waste, the same radioactive waste inventory, and similar trench characteristics and operating procedures. The climate, geology. and hydrology of the two sites are chosen to be typical of real western and eastern sites. Volume 1 (Main Report) contains background information and study results in summary form.

  14. Technology, Safety and Costs of Decommissioning a Reference Low-Level Waste Burial Ground. Main Report

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, E. S.; Holter, G. M.

    1980-06-01

    Safety and cost information are developed for the conceptual decommissioning of commercial low-level waste (LLW) burial grounds. Two generic burial grounds, one located on an arid western site and the other located on a humid eastern site, are used as reference facilities for the study. The two burial grounds are assumed to have the same site capacity for waste, the same radioactive waste inventory, and similar trench characteristics and operating procedures. The climate, geology. and hydrology of the two sites are chosen to be typical of real western and eastern sites. Volume 1 (Main Report) contains background information and study results in summary form.

  15. Children's level of word knowledge predicts their exclusion of familiar objects as referents of novel words

    Directory of Open Access Journals (Sweden)

    Susanne eGrassmann

    2015-08-01

    Full Text Available When children are learning a novel object label, they tend to exclude as possible referents familiar objects for which they already have a name. In the current study, we wanted to know if children would behave in this same way regardless of how well they knew the name of potential referent objects, specifically, whether they could only comprehend it or they could both comprehend and produce it. Sixty-six monolingual German-speaking 2-, 3-, and 4-year-old children participated in two experimental sessions. In one session the familiar objects were chosen such that their labels were in the children's productive vocabularies, and in the other session the familiar objects were chosen such that their labels were only in the children's receptive vocabularies. Results indicated that children at all three ages were more likely to exclude a familiar object as the potential referent of the novel word if they could comprehend and produce its name rather than comprehend its name only. Indeed, level of word knowledge as operationalized in this way was a better predictor than was age. These results are discussed in the context of current theories of word learning by exclusion.

  16. Dose levels from thoracic and pelvic examinations in two pediatric radiological departments in Norway - a comparison study of dose-area product and radiographic technique

    International Nuclear Information System (INIS)

    Kjernlie Saether, Hilde; Traegde Martinsen, Anne Catrine; Lagesen, Bente; Platou Holsen, Eva; Oevreboe, Kirsti Marie

    2010-01-01

    Background: Pediatric doses expressed in dose-area product (DAP) can be retrieved from only a few publications; most of which correlate DAP to patient size or large age spans. In clinical practice age is often the only available parameter describing the patient, and thus, evaluation of dose levels in pediatric radiology on the basis of DAP related to age alone would be useful in optimization work. Purpose: To provide comparable data on age-related DAP from thoracic and pelvic radiological examinations of children, and evaluate the usefulness of comparing age-related DAP and radiographic technique between systems to identify areas with potential for optimization. Material and Methods: DAP, age, and radiographic technique were registered for 575 thoracic examinations and 371 pelvic examinations of children from newborn up to 14 years of age in groups with an age span of 1 year, performed with two digital flat-panel systems and one computed radiography system. Results: DAP varies from 2.2 to 54.0 mGycm2 for thoracic examinations, and from 4.6 to 532.5 mGycm2 for pelvic examinations. There are significant differences in DAP between systems and departments due to differences in technique, equipment, and staff. Conclusion: This study provides comparable data on age-related DAP from thoracic and pelvic radiological examinations of children, which could be used as an input to estimate diagnostic reference levels. The comparison between systems of DAP and radiographic technique has proven useful in identifying areas where there may be a potential for optimization.

  17. Impact of low-level radiation with special reference to tritium in environment

    International Nuclear Information System (INIS)

    Bhatia, A.L.

    2005-01-01

    Radiation is invisible, but exists in various types, in the form of particles and/or energy bundles. The effects of low-level radiation seem very abstract since these can not be perceived by our sensory organs. The increase in natural background radiation from various inadvertent sources like tritium has the prospect of altering the entire scenario of billions of years' slow and steady biogenetic evolution. Mankind, by developing atomic technologies, is unleashing forces which it does understand but not beyond experimental findings. There is no wise sorcerer who can undo the damage we are causing. Tritium is a radioactive form of hydrogen that is produced in the reactor core. The released tritium replaces hydrogen in water. Tritium in water when gets ingested, causes continuos internal low-level beta radiation exposure over a long period. Proposed presentation will focus on the possible long term damage caused by its low-level exposure is dependent on the length of duration living tissue spends in the radiation field, not on the relative radiation field strength. As internal radiation pulses never stop, impact is continuous by the ambient radiation atmosphere. There is no chance to heal at the molecular level, except small chances of DNA repair since the organically bound tritium has greater severe influence with the slow turnover. Though the situation needs not be alarming with tritium, the studies on radiation damage on various parameters have given evidence of two compartments of radiation damage; the reparable or potentially lethal and the irreparable or lethal. With emerging new reports on the stochastic effects, those for which the probability, rather than the severity of an effect from tritium occurring as a function of dose also can not be ruled out. Biotoxicity of tritium in the form of induction of cancer, hereditary effects, teratogenesis and life shortening really needs an exhaustive investigation and warrants careful evaluation. However, a positive

  18. Center of cancer systems biology second annual workshop--tumor metronomics: timing and dose level dynamics.

    Science.gov (United States)

    Hahnfeldt, Philip; Hlatky, Lynn; Klement, Giannoula Lakka

    2013-05-15

    Metronomic chemotherapy, the delivery of doses in a low, regular manner so as to avoid toxic side effects, was introduced over 12 years ago in the face of substantial clinical and preclinical evidence supporting its tumor-suppressive capability. It constituted a marked departure from the classic maximum-tolerated dose (MTD) strategy, which, given its goal of rapid eradication, uses dosing sufficiently intense to require rest periods between cycles to limit toxicity. Even so, upfront tumor eradication is frequently not achieved with MTD, whereupon a de facto goal of longer-term tumor control is often pursued. As metronomic dosing has shown tumor control capability, even for cancers that have become resistant to the same drug delivered under MTD, the question arises whether it may be a preferable alternative dosing approach from the outset. To date, however, our knowledge of the coupled dynamics underlying metronomic dosing is neither sufficiently well developed nor widely enough disseminated to establish its actual potential. Meeting organizers thus felt the time was right, armed with new quantitative approaches, to call a workshop on "Tumor Metronomics: Timing and Dose Level Dynamics" to explore prospects for gaining a deeper, systems-level appreciation of the metronomics concept. The workshop proved to be a forum in which experts from the clinical, biologic, mathematical, and computational realms could work together to clarify the principles and underpinnings of metronomics. Among other things, the need for significant shifts in thinking regarding endpoints to be used as clinical standards of therapeutic progress was recognized. ©2013 AACR.

  19. Serum level modifications of female sex hormones after radiocastration with different total doses

    International Nuclear Information System (INIS)

    Naujokat, B.; Rohloff, R.; Willich, N.; Eiermann, W.

    1988-01-01

    We determined serum level of estradiol, FSH and LH over a period of six to eight weeks after ovarian irradiation for castration with different doses (2x2.5 Gy/3x2.5 Gy/4x2.5 Gy) in 15 patients with metastatic breast cancer as compared to changes after ovarectomy in five patients. The time course of the changing estradiol-, FSH and LH-serum levels sigificantly depends on the ovarian dose. After radiological castration with a dose of 4x2.5 Gy = 10 Gy in four days the estrogen levels decrease within two to three weeks, and the FSH- and LH-levels increase after three to four weeks into the postmenopausal range. Therefore, the time course is not very different from changes after ovarectomy. (orig.) [de

  20. Lethal doses of ionizing radiation versus endogenous level of superoxide dismutase

    Energy Technology Data Exchange (ETDEWEB)

    Lipecka, K; Domanski, T; Dniaszewska, K; Grabowska, B; Pietrowicz, D; Lindner, P; Cisowska, B; Gorski, H [Military Medical Academy, Lodz (Poland). Inst. of Occupational Medicine

    1982-06-22

    The stability of superoxide dismutase (SOD) as well as its activity distribution in a human population were investigated. The SOD activity level of the erythrocytes proved to be an index for the endogenous SOD activity in the whole body. In a rat population, having similar SOD frequency distribution as a human population, the mortality due to acute irradiation depended on the SOD level; after a single acute dose approximating the lethal dose (LD/sub 50/30/) the survival depended distinctly on the endogenous SOD activity level.

  1. Influence of Erythropoietin Dose and Albumin Level on the Plasma Brain Natriuretic Peptide in Hemodialysis Patients

    Directory of Open Access Journals (Sweden)

    Alsuwaida Abdulkareem

    2006-01-01

    Full Text Available Brain natriuretic peptide (BNP levels increase in patients with congestive heart failure. Theoretically, BNP levels can be helpful in the determination of the "dry weight" of hemodialysis patients. To evaluate the effect of hemodialysis on the plasma concentration of BNP and to determine the factors that affect BNP levels during hemodialysis in patients with chronic renal failure, we studied five stable patients with chronic renal failure. A total of 15 blood samples were obtained for BNP levels at 24, 48 and 72 hours after the last hemodialysis session. The plasma BNP levels did not change significantly either with ultrafiltration volume or with time since last dialysis. However, the BNP levels correlated positively with the erythropoietin (EPO dose (r=0.98, P< 0.001 and negatively with the serum albumin levels (r = 0.94, P=0.02. Univariate analysis showed that the EPO dose (P=0.001 and the albumin level (P=0.02 were significant predictors of BNP level. Adjusted multivariate analysis showed significant interaction between the EPO dose and the albumin level (P=0.01, P=0.03 respectively. In conclusion: the plasma BNP levels were not significantly influenced by ultrafiltration volume or time since last dialysis. However, the BNP levels may be a useful prognostic parameter for assessing the risk of cardiovascular morbidity and mortality in hemodialysis patients.

  2. Epidemiological surveys on the effects of low-level radiation dose: a comparative assessment. V. E

    Energy Technology Data Exchange (ETDEWEB)

    Rose, K.S.B.

    1990-01-01

    These tables present data on the effects of low-level radiation dose for the following effects:- pre-conception irradiation and Down's Syndrome, pre-conception irradiation and reproductive damage, surveys of effect in relation to the source of radiation, distribution by maternal preconception exposure of the 7 most common major congenital abnormalities in the Japanese, pre-conception irradiation and childhood malignancies, parental gonadal dose at Hiroshima and Nagasaki in relation to leukemia, sex chromosome aneuploids in children of A-bomb survivors, untoward pregnancy outcomes by parental gonad dose, pre-conception irradiation and chromosomal abnormalities, and intra-uterine irradiation and intelligence. (author).

  3. Epidemiological surveys on the effects of low-level radiation dose: a comparative assessment. V. E

    International Nuclear Information System (INIS)

    Rose, K.S.B.

    1990-01-01

    These tables present data on the effects of low-level radiation dose for the following effects:- pre-conception irradiation and Down's Syndrome, pre-conception irradiation and reproductive damage, surveys of effect in relation to the source of radiation, distribution by maternal preconception exposure of the 7 most common major congenital abnormalities in the Japanese, pre-conception irradiation and childhood malignancies, parental gonadal dose at Hiroshima and Nagasaki in relation to leukemia, sex chromosome aneuploids in children of A-bomb survivors, untoward pregnancy outcomes by parental gonad dose, pre-conception irradiation and chromosomal abnormalities, and intra-uterine irradiation and intelligence. (author)

  4. Using the Concept of "Population Dose" in Planning and Evaluating Community-Level Obesity Prevention Initiatives

    Science.gov (United States)

    Cheadle, Allen; Schwartz, Pamela M.; Rauzon, Suzanne; Bourcier, Emily; Senter, Sandra; Spring, Rebecca; Beery, William L.

    2013-01-01

    When planning and evaluating community-level initiatives focused on policy and environment change, it is useful to have estimates of the impact on behavioral outcomes of particular strategies (e.g., building a new walking trail to promote physical activity). We have created a measure of estimated strategy-level impact--"population dose"--based on…

  5. Comparative analysis of dose levels to patients in radiological procedures guided by fluoroscopy

    International Nuclear Information System (INIS)

    Gomez, Pablo Luis; Fernandez, Manuel; Ramos, Julio A.; Delgado, Jose Miguel; Cons, Nestor

    2013-01-01

    This work presents the comparative data of the dose indicators for patient in radiological processes with respect to the values published in the ICRP document. It is analyzed the need for different strategies to communicate to different specialists mechanisms to optimize the radiation beginning with practice by training of second degree level in radiological protection and then, working with them the basics of equipment management to reduce doses without detriment to the welfare purpose

  6. Serum tocopherol levels in very preterm infants after a single dose of vitamin E at birth.

    Science.gov (United States)

    Bell, Edward F; Hansen, Nellie I; Brion, Luc P; Ehrenkranz, Richard A; Kennedy, Kathleen A; Walsh, Michele C; Shankaran, Seetha; Acarregui, Michael J; Johnson, Karen J; Hale, Ellen C; Messina, Lynn A; Crawford, Margaret M; Laptook, Abbot R; Goldberg, Ronald N; Van Meurs, Krisa P; Carlo, Waldemar A; Poindexter, Brenda B; Faix, Roger G; Carlton, David P; Watterberg, Kristi L; Ellsbury, Dan L; Das, Abhik; Higgins, Rosemary D

    2013-12-01

    Our aim was to examine the impact of a single enteral dose of vitamin E on serum tocopherol levels. The study was undertaken to see whether a single dose of vitamin E soon after birth can rapidly increase the low α-tocopherol levels seen in very preterm infants. If so, this intervention could be tested as a means of reducing the risk of intracranial hemorrhage. Ninety-three infants vitamin E or placebo by gastric tube within 4 hours of birth. The vitamin E group received 50 IU/kg of vitamin E as dl-α-tocopheryl acetate (Aquasol E). The placebo group received sterile water. Blood samples were taken for measurement of serum tocopherol levels by high-performance liquid chromatography before dosing and 24 hours and 7 days after dosing. Eighty-eight infants received the study drug and were included in the analyses. The α-tocopherol levels were similar between the groups at baseline but higher in the vitamin E group at 24 hours (median 0.63 mg/dL vs. 0.42 mg/dL, P = .003) and 7 days (2.21 mg/dL vs 1.86 mg/dL, P = .04). There were no differences between groups in γ-tocopherol levels. At 24 hours, 30% of vitamin E infants and 62% of placebo infants had α-tocopherol levels vitamin E raised serum α-tocopherol levels, but to consistently achieve α-tocopherol levels >0.5 mg/dL, a higher dose or several doses of vitamin E may be needed.

  7. Determination of Natural Levels of Radionuclides in Proposed Mushroom Reference Material (A Proficiency Test Exercise)

    International Nuclear Information System (INIS)

    Waheed, S.; Rahman, A.; Siddique, N.; Ahmad, S.; Zaidi, J.H.

    2006-08-01

    A proficiency test (PT) was organized within the framework of international Atomic Energy Agency (IAEA) project INT/1/054, entitled 'Preparation' of Reference Materials and Organization of Proficiency Test Rounds'. This exercise served to estimate the proficiency of the analytical laboratories from participating countries. This report presents the results of the proficiency test exercise on the proposed Mushroom Reference Material for the determination of natural levels of radionuclides. Laboratories from 6 different countries submitted data on the following three radionuclides: /sup 134/Cs, /sup 137/Cs, /sup 40/K. Results for /sup 134/Cs, 137/sup 137/Cs, and /sup 40/K in the mushroom reference material were reported by three or more participating laboratories and could be subjected to statistical evaluation. The original data of these raionuclides was subjected to a computer program 'Histo Vession 2.1' provided by IAEA. The four outlier tests i.e. Dixon, Grubbs, Skewness and Kurtosis were applied to the data sets. All values for these three radionuclides were accepted by the software. Consensus (overall) mean value, absolute standard deviation, relative standard deviation, standard error, median and range of values for these three radionuclides have been are obtained (at significance level 0.05). the consensus mean values and confidence intervals are given./sup 134/Cs: 4.4 Bq/kg (3.4-5.3 Bq/kg) /sup 137/Cs: 2899 Bq/kg (2740-3058 Bq/kg) /sup 40/K: 1136 Bq/kg (1046-1226 Bq/kg). (author)

  8. French diagnostic reference levels in diagnostic radiology, computed tomography and nuclear medicine: 2004-2008 Review

    International Nuclear Information System (INIS)

    Roch, P.; Aubert, B.

    2013-01-01

    After 5 y of collecting data on diagnostic reference levels (DRLs), the Nuclear Safety and Radiation Protection French Inst. (IRSN) presents the analyses of this data. The analyses of the collected data for radiology, computed tomography (CT) and nuclear medicine allow IRSN to estimate the level of regulatory application by health professionals and the representativeness of current DRL in terms of relevant examinations, dosimetric quantities, numerical values and patient morphologies. Since 2004, the involvement of professionals has highly increased, especially in nuclear medicine, followed by CT and then by radiology. Analyses show some discordance between regulatory examinations and clinical practice. Some of the dosimetric quantities used for the DRL setting are insufficient or not relevant enough, and some numerical values should also be reviewed. On the basis of these findings, IRSN formulates recommendations to update regulatory DRL with current and relevant examination lists, dosimetric quantities and numerical values. (authors)

  9. Modelling of Biota Dose Effects. Report of Working Group 6 Biota Dose Effects Modelling of EMRAS II Topical Heading Reference Approaches for Biota Dose Assessment. Environmental Modelling for RAdiation Safety (EMRAS II) Programme

    International Nuclear Information System (INIS)

    2014-07-01

    Environmental assessment models are used for evaluating the radiological impact of actual and potential releases of radionuclides to the environment. They are essential tools for use in the regulatory control of routine discharges to the environment and in planning the measures to be taken in the event of accidental releases. They are also used for predicting the impact of releases which may occur far into the future, for example, from underground radioactive waste repositories. It is important to verify, to the extent possible, the reliability of the predictions of such models by a comparison with measured values in the environment or with the predictions of other models. The IAEA has been organizing programmes on international model testing since the 1980s. These programmes have contributed to a general improvement in models, in the transfer of data and in the capabilities of modellers in Member States. IAEA publications on this subject over the past three decades demonstrate the comprehensive nature of the programmes and record the associated advances which have been made. From 2009 to 2011, the IAEA organized a project entitled Environmental Modelling for RAdiation Safety (EMRAS II), which concentrated on the improvement of environmental transfer models and the development of reference approaches to estimate the radiological impacts on humans, as well as on flora and fauna, arising from radionuclides in the environment. Different aspects were addressed by nine working groups covering three themes: reference approaches for human dose assessment, reference approaches for biota dose assessment and approaches for addressing emergency situations. This publication describes the work of the Biota Effects Modelling Working Group

  10. Modelling of Biota Dose Effects. Report of Working Group 6 Biota Dose Effects Modelling of EMRAS II Topical Heading Reference Approaches for Biota Dose Assessment. Environmental Modelling for RAdiation Safety (EMRAS II) Programme

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-07-15

    Environmental assessment models are used for evaluating the radiological impact of actual and potential releases of radionuclides to the environment. They are essential tools for use in the regulatory control of routine discharges to the environment and in planning the measures to be taken in the event of accidental releases. They are also used for predicting the impact of releases which may occur far into the future, for example, from underground radioactive waste repositories. It is important to verify, to the extent possible, the reliability of the predictions of such models by a comparison with measured values in the environment or with the predictions of other models. The IAEA has been organizing programmes on international model testing since the 1980s. These programmes have contributed to a general improvement in models, in the transfer of data and in the capabilities of modellers in Member States. IAEA publications on this subject over the past three decades demonstrate the comprehensive nature of the programmes and record the associated advances which have been made. From 2009 to 2011, the IAEA organized a project entitled Environmental Modelling for RAdiation Safety (EMRAS II), which concentrated on the improvement of environmental transfer models and the development of reference approaches to estimate the radiological impacts on humans, as well as on flora and fauna, arising from radionuclides in the environment. Different aspects were addressed by nine working groups covering three themes: reference approaches for human dose assessment, reference approaches for biota dose assessment and approaches for addressing emergency situations. This publication describes the work of the Biota Effects Modelling Working Group.

  11. Effects of irradiation source and dose level on quality characteristics of processed meat products

    Science.gov (United States)

    Ham, Youn-Kyung; Kim, Hyun-Wook; Hwang, Ko-Eun; Song, Dong-Heon; Kim, Yong-Jae; Choi, Yun-Sang; Song, Beom-Seok; Park, Jong-Heum; Kim, Cheon-Jei

    2017-01-01

    The effect of irradiation source (gamma-ray, electron-beam, and X-ray) and dose levels on the physicochemical, organoleptic and microbial properties of cooked beef patties and pork sausages was studied, during 10 days of storage at 30±1 °C. The processed meat products were irradiated at 0, 2.5, 5, 7.5, and 10 kGy by three different irradiation sources. The pH of cooked beef patties and pork sausages was unaffected by irradiation sources or their doses. The redness of beef patties linearly decreased with increasing dose level (Pchanges in overall acceptability were observed for pork sausages regardless of irradiation source (P>0.05), while gamma-ray irradiated beef patties showed significantly decreased overall acceptability in a dose-dependent manner (Poxidation of samples was accelerated by irradiation depending on irradiation sources and dose levels during storage at 30 °C. E-beam reduced total aerobic bacteria of beef patties more effectively, while gamma-ray considerably decreased microbes in pork sausages as irradiation dose increased. The results of this study indicate that quality attributes of meat products, in particular color, lipid oxidation, and microbial properties are significantly influenced by the irradiation sources.

  12. 23 CFR Appendix A to Part 772 - National Reference Energy Mean Emission Levels as a Function of Speed

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false National Reference Energy Mean Emission Levels as a Function of Speed A Appendix A to Part 772 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF... NOISE Pt. 772, App. A Appendix A to Part 772—National Reference Energy Mean Emission Levels as a...

  13. 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.

  14. Adduction of acrylamide with biomacromolecules at environmental dose level measured by accelerator mass spectrometry (AMS)

    International Nuclear Information System (INIS)

    Xie, Q.Y.; Sun, H.F.; Liu, Y.F.; Ding, X.F.; Fu, D.P.; Liu, K.X.

    2005-01-01

    Acrylamide (AA) is a well-known neurotoxin, which also has developmental, reproductive as well as genetic toxicity. AA has been classified as a probable human carcinogen by IARC in 1994 since its carcinogenic effects in animals were reported after repetitive high level dosing. Over the last 10 years, there have been a large number of studies investigating the effects of AA on rodent reproductive performance. In 2002, the Swedish Food Administration reported the presence of AA in the heat-treated food products. which again elicited great concern on the toxicity of AA. However most of these studies were investigated at a dose level of mg/kg b.w and above, which is much higher than the actual human relevant dose. In this study we investigate the adduction of environmental level AA with biomacromolecules by the ultra-sensitive AMS technique. This may provide some information on the reproductive toxicity of AA under extremely low level exposure. A series doses of [2, 3- 14 C] AA (0, 0.1, 1, 10, 100, 250, 1000 μg/kg bw) were administrated with a single intraperitoneal injection (i.p.) to ICR adult male mice. The blood and spermatozoon were collected 24 h post dosing. Hemoglobin (Hb), serum albumin (SA), protamine, spermatozoon DNA, spermatozoon head and tail were isolated respectively, and then transformed into graphite following our previous procedure, The adduct levels were determined by a 0.6 MV compact AMS facility at the Institute of Heavy Ion Physics of Peking University. The results indicate that: (1) AA adduct number increases with the doses within 0.1-1000 μg/kg b.w. range in a log/log linear mode, except for DNA within 10-1000 μg/kg b.w. range. (2) Comparing protamine, Hb, and SA adducts with that of spermatozoon DNA (see Fig. 1), AA mainly adducts to proteins. For instance, at 1000 μg/kg b.w. dose level, spermatozoon DNA adducts only account for about 0.71%, 1.36% and 0.82% of protamine, Hb and SA adducts, respectively. (3) AA-protamine adducts, AA

  15. Supplementary comparison CCRI(I)-S2 of standards for absorbed dose to water in 60Co gamma radiation at radiation processing dose levels

    DEFF Research Database (Denmark)

    Burns, D. T.; Allisy-Roberts, P. J.; Desrosiers, M. F.

    2011-01-01

    Eight national standards for absorbed dose to water in 60Co gamma radiation at the dose levels used in radiation processing have been compared over the range from 1 kGy to 30 kGy using the alanine dosimeters of the NIST and the NPL as the transfer dosimeters. The comparison was organized...... by the Bureau International des Poids et Mesures, who also participated at the lowest dose level using their radiotherapy-level standard for the same quantity. The national standards are in general agreement within the standard uncertainties, which are in the range from 1 to 2 parts in 102. Evidence of a dose...

  16. Determination of high level absorbed dose in a 60Co gamma ray field with ionization chambers

    International Nuclear Information System (INIS)

    Zhongying Li; Benjiang Mao; Lu Zhang

    1995-01-01

    This paper relates to the principles and methods for determining the absorbed dose of high energy photons radiation with ionization chambers, and its shows the doserate results of high level 60 Co γ-rays in water measured with Farmer chambers. The results with two kinds of chambers at a same point are consistent within 0.3%, and the total uncertainty is less than ± 4%. In the domestic intercomparison on determining high level absorbed dose in which 12 laboratories participated, the deviation of our result from the mean result of the intercomparison is -0.04% [Chen Yundong (1992). Summing up report on a high level absorbed dose intercomparison (in Chinese)]. (author)

  17. Yield and Chemical Composition of Cucumber Treated by Nitrogen Levels and Doses of Gamma Rays

    International Nuclear Information System (INIS)

    Fath El-Bab, T.Sh.; Abo El-Khier, Om.M.; Abdallah, A.A.G.

    2013-01-01

    Two field experiments were performed at the Atomic Energy Authority, Experimental farm, Inshas, Egypt during 2010 and 2011 summer growing seasons in sandy soil. The experiments were conducted to study the effect of pre-sowing seeds which treated by gamma irradiation with different doses of 0, 2, 4 and 6 Gy. This was in combination with three rates of nitrogen, fertilizer i.e., 30, 60 and 90 Kg N/fed. The experiments were laid out using drip irrigation system. The obtained results indicated that gamma rays doses showed significant differences on cucumber yield per plot or per Fed., increasing doses of gamma rays gradually increased cucumber yield per plot up to highest dose, i.e., (6 Gy). The highest value of total yield was obtained with the highest nitrogen rate (90 Kg N/fed.). Doses of gamma rays significantly increased total soluble solids (T.S.S.), total Carbohydrates, fats, total protein, NPK and Ca of cucumber fruits. Application of 60 Kg N/fed. recorded the highest values of all above mentioned chemical characters except of total protein with 90 kg N/fed. every all dose treatments. The effect of interaction between doses and fertilizer levels on chemical characters were significant therefore, the highest values was found at 4 Gy and 60 Kg N/fed. treatment for protein, fat, nitrogen and potassium contents while the carbohydrate and calcium contents had the highest value with the treatment of 6 Gy and 60 Kg N/fed

  18. Background levels and radiation dose yield of o-tyrosine in chicken meat

    International Nuclear Information System (INIS)

    Chuaqui-Offermanns, N.; McDougall, T.

    1991-01-01

    The measurement of o-tyrosine levels in poultry meat is a potential method for postirradiation dosimetry of poultry. The validity of using o-tyrosine for this purpose has not yet been established. As part of the validation process, the o-tyrosine content in unirradiated chicken meat, the radiation dose response curve, and the effects of postirradiation storage on o-tyrosine levels are examined. In 18 individual samples, the mean background level of o-tyrosine was 0.18 +/- 0.11 ppm (wet weight, 70% moisture), and the most frequent background level (60% of the cases) was between 0.05 and 0.15 ppm (wet weight, 70% moisture). In pooled samples of 10 chickens, the mean background level was 0.12 +/- 0.03 ppm (wet weight, 70% moisture). The levels were not significantly affected by storage at 5 degrees C (7 d) or by freezing the sample. The radiation dose response curve was linear within the dose range studied (0 to 10 kGy), with a slope of 0.127 + 0.003 ppm (wet weight)/kGy. Although there was some variation in the intercept (0.132 + 0.013), the slope was the same in all samples tested. Postirradiation storage at either 4 or 8 degrees C until spoilage did not affect the levels of o-tyrosine. These data indicate that o-tyrosine level may be useful for determining the absorbed dose in chicken meat gamma-irradiated to doses greater than 0.6 kGy. Further validation studies are continuing

  19. Survey of doses and frequency of X-ray examinations on children at the intensive care unit of a large reference pediatric hospital

    International Nuclear Information System (INIS)

    Pedrosa de Azevedo, Ana Cecilia; Osibote, Adelaja Otolorin; Bastos Boechat, Marcia Cristina

    2006-01-01

    Objective: This work aims to evaluate the entrance surface dose (ESD), the body organ dose (BOD) and the effective dose (E) resulting from pediatric radiological procedures with the use of portable X-ray equipments. Materials and methods: The software DoseCal was used to evaluate the doses imparted to patients. The children were classified according to their weight and age groups, and the study included three sectors of the intensive care unit of a large reference pediatric hospital in Rio de Janeiro. Results: A total of 518 radiographs have been performed (424 for chest and 94 for abdomen). The statistical data were compared with previously published results. The BOD is presented for the most exposed organs. Conclusion: The mean value of ESD and E varied widely among neonates. The highest number of radiographs per infant peaked 33 for chest examination in the age group 0-1 year

  20. Low-level radioactive waste technology: a selected, annotated bibliography. [416 references

    Energy Technology Data Exchange (ETDEWEB)

    Fore, C.S.; Carrier, R.F.; Brewster, R.H.; Hyder, L.K.; Barnes, K.A.

    1981-10-01

    This annotated bibliography of 416 references represents the third in a series to be published by the Hazardous Materials Information Center containing scientific, technical, economic, and regulatory information relevant to low-level radioactive waste technology. The bibliography focuses on disposal site, environmental transport, and waste treatment studies as well as general reviews on the subject. The publication covers both domestic and foreign literature for the period 1951 to 1981. Major chapters selected are Chemical and Physical Aspects; Container Design and Performance; Disposal Site; Environmental Transport; General Studies and Reviews; Geology, Hydrology, and Site Resources; Regulatory and Economic Aspects; Social Aspects; Transportation Technology; Waste Production; and Waste Treatment. Entries in each of the chapters are further classified as a field study, laboratory study, theoretical study, or general overview involving one or more of these research areas.

  1. 1-GWh diurnal load-leveling superconducting magnetic energy storage system reference design

    International Nuclear Information System (INIS)

    Hassenzahl, W.V.; Rogers, J.D.

    1979-01-01

    A point reference design has been completed for a 1-GWh Superconducting Magnetic Energy Storage system. The system is for electric utility dirunal load leveling; however, such a device will function to meet much faster power demands including dynamic stabilization. The study has explored several concepts of design not previously considered in the same detail as treated here. Because the study is for a point design, optimization in all respects is not complete. The study examines aspects of the coil design; superconductor supported off of the dewar shell; the dewar shell, its configuration and stresses; the underground excavation and related construction for holding the superconducting coil and its dewar; the helium refrigeration system; the electrical converter system; the vacuum system; the guard coil; and the costs. The report is a condensation of the more comprehensive study which is in the process of being printed

  2. Nanosecond-level time synchronization of AERA using a beacon reference transmitter and commercial airplanes

    Directory of Open Access Journals (Sweden)

    Huege Tim

    2017-01-01

    Full Text Available Radio detection of cosmic-ray air showers requires time synchronization of detectors on a nanosecond level, especially for advanced reconstruction algorithms based on the wavefront curvature and for interferometric analysis approaches. At the Auger Engineering Radio Array, the distributed, autonomous detector stations are time-synchronized via the Global Positioning System which, however, does not provide sufficient timing accuracy. We thus employ a dedicated beacon reference transmitter to correct for eventby-event clock drifts in our offline data analysis. In an independent cross-check of this “beacon correction” using radio pulses emitted by commercial airplanes, we have shown that the combined timing accuracy of the two methods is better than 2 nanoseconds.

  3. Nanosecond-level time synchronization of AERA using a beacon reference transmitter and commercial airplanes

    Science.gov (United States)

    Huege, Tim

    2017-03-01

    Radio detection of cosmic-ray air showers requires time synchronization of detectors on a nanosecond level, especially for advanced reconstruction algorithms based on the wavefront curvature and for interferometric analysis approaches. At the Auger Engineering Radio Array, the distributed, autonomous detector stations are time-synchronized via the Global Positioning System which, however, does not provide sufficient timing accuracy. We thus employ a dedicated beacon reference transmitter to correct for eventby-event clock drifts in our offline data analysis. In an independent cross-check of this "beacon correction" using radio pulses emitted by commercial airplanes, we have shown that the combined timing accuracy of the two methods is better than 2 nanoseconds.

  4. Radiation doses and possible radiation effects of low-level, chronic radiation in vegetation

    International Nuclear Information System (INIS)

    Rhoads, W.A.; Franks, L.A.

    1975-01-01

    Measurements were made of radiation doses in soil and vegetation in Pu-contaminated areas at the Nevada Test Site with the objective of investigating low-level, low-energy gamma radiation (with some beta radiation) effects at the cytological or morphological level in native shrubs. In this preliminary investigation, the exposure doses to shrubs at the approximate height of stem apical meristems were estimated from 35 to 140 R for a ten-year period. The gamma exposure dose estimated for the same period was 20.7 percent +- 6.4 percent of that recorded by the dosimeters used in several kinds of field instrument surveys. Hence, a survey instrument reading made at about 25 cm in the tops of shrubs should indicate about 1 / 5 the dosimeter-measured exposures. No cytology has yet been undertaken because of the drought since last winter. (auth)

  5. The calculation of dose from external photon exposures using reference human phantoms and Monte Carlo methods. Pt. 7. Organ doses due to parallel and environmental exposure geometries

    Energy Technology Data Exchange (ETDEWEB)

    Zankl, M. [GSF - Forschungszentrum fuer Umwelt und Gesundheit Neuherberg GmbH, Oberschleissheim (Germany). Inst. fuer Strahlenschutz; Drexler, G. [GSF - Forschungszentrum fuer Umwelt und Gesundheit Neuherberg GmbH, Oberschleissheim (Germany). Inst. fuer Strahlenschutz; Petoussi-Henss, N. [GSF - Forschungszentrum fuer Umwelt und Gesundheit Neuherberg GmbH, Oberschleissheim (Germany). Inst. fuer Strahlenschutz; Saito, K. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)

    1997-03-01

    This report presents a tabulation of organ and tissue equivalent dose as well as effective dose conversion coefficients, normalised to air kerma free in air, for occupational exposures and environmental exposures of the public to external photon radiation. For occupational exposures, whole-body irradiation with idealised geometries, i.e. broad parallel beams and fully isotropic radiation incidence, is considered. The directions of incidence for the parallel beams are anterior-posterior, posterior-anterior, left lateral, right lateral and a full 360 rotation around the body`s longitudinal axis. The influence of beam divergence on the body doses is also considered as well as the dependence of effective dose on the angle of radiation incidence. Regarding exposure of the public to environmental sources, three source geometries are considered: exposure from a radioactive cloud, from ground contamination and from the natural radionuclides distributed homogeneously in the ground. The precise angular and energy distributions of the gamma rays incident on the human body were taken into account. The organ dose conversion coefficients given in this catalogue were calculated using a Monte Carlo code simulating the photon transport in mathematical models of an adult male and an adult female, respectively. Conversion coefficients are given for the equivalent dose of 23 organs and tissues as well as for effective dose and the equivalent dose of the so-called `remainder`. The organ equivalent dose conversion coefficients are given separately for the adult male and female models and - as arithmetic mean of the conversion coefficients of both - for an average adult. Fitted data of the coefficients are presented in tables; the primary raw data as resulting from the Monte Carlo calculation are shown in figures together with the fitted data. (orig.)

  6. The calculation of dose from external photon exposures using reference human phantoms and Monte Carlo methods. Pt. 7. Organ doses due to parallel and environmental exposure geometries

    International Nuclear Information System (INIS)

    Zankl, M.

    1997-03-01

    This report presents a tabulation of organ and tissue equivalent dose as well as effective dose conversion coefficients, normalised to air kerma free in air, for occupational exposures and environmental exposures of the public to external photon radiation. For occupational exposures, whole-body irradiation with idealised geometries, i.e. broad parallel beams and fully isotropic radiation incidence, is considered. The directions of incidence for the parallel beams are anterior-posterior, posterior-anterior, left lateral, right lateral and a full 360 rotation around the body's longitudinal axis. The influence of beam divergence on the body doses is also considered as well as the dependence of effective dose on the angle of radiation incidence. Regarding exposure of the public to environmental sources, three source geometries are considered: exposure from a radioactive cloud, from ground contamination and from the natural radionuclides distributed homogeneously in the ground. The precise angular and energy distributions of the gamma rays incident on the human body were taken into account. The organ dose conversion coefficients given in this catalogue were calculated using a Monte Carlo code simulating the photon transport in mathematical models of an adult male and an adult female, respectively. Conversion coefficients are given for the equivalent dose of 23 organs and tissues as well as for effective dose and the equivalent dose of the so-called 'remainder'. The organ equivalent dose conversion coefficients are given separately for the adult male and female models and - as arithmetic mean of the conversion coefficients of both - for an average adult. Fitted data of the coefficients are presented in tables; the primary raw data as resulting from the Monte Carlo calculation are shown in figures together with the fitted data. (orig.)

  7. Comparison BIPM.RI(I)-K8 of high dose-rate Ir-192 brachytherapy standards for reference air kerma rate of the VSL and the BIPM

    DEFF Research Database (Denmark)

    Alvarez, J.T.; De Pooter, J.A.; Andersen, Claus E.

    2014-01-01

    An indirect comparison of the standards for reference air kerma rate for 192Ir high dose rate brachytherapy sources of the Dutch Metrology Institute (VSL), The Netherlands, and of the Bureau International des Poids et Mesures (BIPM) was carried out at the VSL in November 2009. The comparison resu...

  8. Developing regional weight-for-age growth references for malaria-endemic countries to optimize age-based dosing of antimalarials

    NARCIS (Netherlands)

    Hayes, Daniel J.; van Buuren, Stef; ter Kuile, Feiko O.; Stasinopoulos, D. Mikis; Rigby, Robert A.; Terlouw, Dianne J.

    2015-01-01

    To derive regional weight-for-age growth references to help optimize age-based dosing of antimalarials in Africa, the Americas, South-East Asia and the Western Pacific. A weight-for-age database was constructed from pre-existing population-based anthropometric data obtained from household surveys

  9. Dose levels due to neutrons in the vicinity of high energy medical accelerators

    International Nuclear Information System (INIS)

    McGinley, P.H.; Wood, M.; Sohrabi, M.; Mills, M.; Rodriguez, R.

    1976-01-01

    High energy photons are generated for use in radiation therapy by the decelleration of electrons in metal targets. Fast neutrons are also generated as a result of (γ, n) and (e, e'n) interactions in the target, beam compensator filter, and collimator material. In this work the adsorbed dose to neutrons was measured at the center of a 10 x 10 cm photon beam and 5 cm outside of the beam edge for a number of treatment units. Dose levels due to slow and fast neutrons were also established outside of the treatment rooms and a Bonner sphere neutron spectrometer system was employed to determine the neutron energy spectrum due to stray neutron radiation at each accelerator. For the linac it was found that the neutron dose at the beam center was 0.0039% of the photon dose and values of 0.049% and 0.053% were observed for the Allis Chalmers betatron and the Brown Boveri Betatron. Dose equivalent rates in the range of 0.3 to 22.5 mrem/hr were measured for points outside the treatment rooms when the accelerators were operated at a photon dose rate of 100 rad/min at the treatment position

  10. Epidemiological survey of the effects of low level radiation dose: a comparative assessment

    Energy Technology Data Exchange (ETDEWEB)

    Rose, K.S.B.

    1993-10-01

    This volume presents the collations tables of a six volume comparative epidemiological survey of the effects of low level radiation dose. Data are collated for the effects observed in the following irradiated groups:- Preconception irradiation, intra-uterine irradiation, childhood irradiation, adult irradiation. (UK).

  11. Effects of bud loading levels and nitrogen doses on yield, physical ...

    African Journals Online (AJOL)

    The aim of this study was to investigate the effects of several bud loading levels in winter pruning and nitrogen doses on yield and physical and chemical properties of fresh vine-leaves of grape cultivar “Narince”. Vines trained with bilateral cordon system was pruned to yield 35000 to 53000 buds/ha (16 or 24 buds/vine) ...

  12. Measurement of extremely low level dose with LiF(Mg,Cu,P) TL chips

    International Nuclear Information System (INIS)

    Zha Ziying; Wang Shoushan; Wu Fang; Chen Guolong; Li Yuanfang; Zhu Jianhuan

    1986-01-01

    This paper presents some of the dosimetric characteristics of newly developed LiF(Mg,Cu,P) TL chips with high signal-to-noise ratio for measurement at the 10 -7 to 10 -4 Gy dose level. Measuring techniques and optimum procedures for annealing and readout are also presented. (author)

  13. Level of terrestrial gamma radiation and doses to population in Jiangsu province

    International Nuclear Information System (INIS)

    1985-01-01

    In this paper the results of investigation of terrestrial gamma radiation level in Jiangsu Province are reported and the population doses due to this radiation are estimated. The sketch map of the geographical distribution of the terrestrial gamma radiation level is given. In this investigation FD-71 portable scintillation counters and RSS-111 high pressure ionization chambers were used. The results showed that the terrestrial gamma absorbed dose rates in air for indoors and outdoors were 10.7 x 10 -8 Gy/h and 6.5 x 10 -8 Gy/h (weighted values) respectively. The indoors-to-outdoors ratio was 1.65. The total (indoor plus outdoor) annual effective dose equivalent from terrestrial gamma radiation, averaged over the population in this province, was 6.0 x 10 -4 Sv. The collective annual effective dose equivalent was 3.6 x 10 4 man.Sv. Therefore, the absorbed dose to population in Jiangsu Province is in the range of the normal background

  14. Plasma, salivary and urinary cortisol levels following physiological and stress doses of hydrocortisone in normal volunteers.

    Science.gov (United States)

    Jung, Caroline; Greco, Santo; Nguyen, Hanh H T; Ho, Jui T; Lewis, John G; Torpy, David J; Inder, Warrick J

    2014-11-26

    Glucocorticoid replacement is essential in patients with primary and secondary adrenal insufficiency, but many patients remain on higher than recommended dose regimens. There is no uniformly accepted method to monitor the dose in individual patients. We have compared cortisol concentrations in plasma, saliva and urine achieved following "physiological" and "stress" doses of hydrocortisone as potential methods for monitoring glucocorticoid replacement. Cortisol profiles were measured in plasma, saliva and urine following "physiological" (20 mg oral) or "stress" (50 mg intravenous) doses of hydrocortisone in dexamethasone-suppressed healthy subjects (8 in each group), compared to endogenous cortisol levels (12 subjects). Total plasma cortisol was measured half-hourly, and salivary cortisol and urinary cortisol:creatinine ratio were measured hourly from time 0 (between 0830 and 0900) to 5 h. Endogenous plasma corticosteroid-binding globulin (CBG) levels were measured at time 0 and 5 h, and hourly from time 0 to 5 h following administration of oral or intravenous hydrocortisone. Plasma free cortisol was calculated using Coolens' equation. Plasma, salivary and urine cortisol at 2 h after oral hydrocortisone gave a good indication of peak cortisol concentrations, which were uniformly supraphysiological. Intravenous hydrocortisone administration achieved very high 30 minute cortisol concentrations. Total plasma cortisol correlated significantly with both saliva and urine cortisol after oral and intravenous hydrocortisone (P cortisol and urinary cortisol:creatinine ratio may provide useful alternatives to plasma cortisol measurements to monitor replacement doses in hypoadrenal patients.

  15. Recent results on the linearity of the dose-response relationship for radiation-induced mutations in human cells by low dose levels

    International Nuclear Information System (INIS)

    Traut, H.

    1987-01-01

    Five studies made by various authors in the last years are discussed, which are significant in that the response of human cells to low-dose irradiation is determined directly and not by extrapolation, and which also provide information on the mutagenic effects of low radiation doses. The results of these studies do not indicate any other than a linear response for induction of mutations by low-dose irradiation, nor are there any reasons observable for assuming the existence of a threshold dose. It is very likely therefore that cancer initiation at the low dose level also is characterized by a linear relationship. Although threshold dose levels cannot generally be excluded, and maybe are only too low to be detected by experiment, there is no plausible biophysical argument for assuming the existence of such microdose threshold. (orig./MG) [de

  16. A Terrestrial Reference Frame realised on the observation level using a GPS-LEO satellite constellation

    Science.gov (United States)

    Koenig, Daniel

    2018-02-01

    Applying a one-step integrated process, i.e. by simultaneously processing all data and determining all satellite orbits involved, a Terrestrial Reference Frame (TRF) consisting of a geometric as well as a dynamic part has been determined at the observation level using the EPOS-OC software of Deutsches GeoForschungsZentrum. The satellite systems involved comprise the Global Positioning System (GPS) as well as the twin GRACE spacecrafts. Applying a novel approach, the inherent datum defect has been overcome empirically. In order not to rely on theoretical assumptions this is done by carrying out the TRF estimation based on simulated observations and using the associated satellite orbits as background truth. The datum defect is identified here as the total of all three translations as well as the rotation about the z-axis of the ground station network leading to a rank-deficient estimation problem. To rectify this singularity, datum constraints comprising no-net translation (NNT) conditions in x, y, and z as well as a no-net rotation (NNR) condition about the z-axis are imposed. Thus minimally constrained, the TRF solution covers a time span of roughly a year with daily resolution. For the geometric part the focus is put on Helmert transformations between the a priori and the estimated sets of ground station positions, and the dynamic part is represented by gravity field coefficients of degree one and two. The results of a reference solution reveal the TRF parameters to be estimated reliably with high precision. Moreover, carrying out a comparable two-step approach using the same data and models leads to parameters and observational residuals of worse quality. A validation w.r.t. external sources shows the dynamic origin to coincide at a level of 5 mm or better in x and y, and mostly better than 15 mm in z. Comparing the derived GPS orbits to IGS final orbits as well as analysing the SLR residuals for the GRACE satellites reveals an orbit quality on the few cm level

  17. The calculation of dose from external photon exposures using reference human phantoms and Monte Carlo methods. Pt. 6

    International Nuclear Information System (INIS)

    Zankl, M.; Panzer, W.; Drexler, G.

    1991-11-01

    Computed tomography (CT) is a technique which offers a high diagnostic capability; however, the dose to the patient is high compared to conventional radiography. This report provides a catalogue of organ doses resulting from CT examinations. The organ doses were calculated for the type of CT scanners most commonly used in the FRG and for three different radiation qualities. For the dose calculations, the patients were represented by the adult mathematical phantoms Adam and Eva. The radiation transport in the body was simulated using a Monte Carlo method. The doses were calculated as conversion factors of mean organ doses per air kerma free in air on the axis of rotation. Mean organ dose conversion factors are given per organ and per single CT slice of 1 cm width. The mean dose to an organ resulting from a particular CT examination can be estimated by summing up the contribution to the organ dose from each relevant slice. In order to facilitate the selection of the appropriate slices, a table is given which relates the mathematical phantoms' coordinates to certain anatomical landmarks in the human body. (orig.)

  18. The calculation of dose from external photon exposures using reference human phantoms and Monte-Carlo methods. Pt. 1

    International Nuclear Information System (INIS)

    Kramer, R.; Zankl, M.; Williams, G.; Drexler, G.

    1982-12-01

    By the help of a Monte-Carlo program the dose that single organs, organ groups and bigger or smaller parts of body would receive on an average, caused by an irradiation definitely fixed by the geometry of irradiation and photon energy, can be determined. Thus the phantom in connection with the Monte-Carlo program can be used for several considerations as for example - calculation of dose from occupational exposures - calculation of dose from diagnostic procedures - calculation of dose from radiotherapy procedures. (orig.)

  19. Levels of dose in head exams by TAC in Cuba. Interrelation with parameters of image quality

    International Nuclear Information System (INIS)

    Fleitas Estevez, Ileana; Mora Machado, Roxana de la; Guevara Ferrer, Carmen R.

    2001-01-01

    In the last years an increment in the use of Computer Tomography (CT) has been observed as an efficient diagnostic method. On the other hand, this type of study involves high doses levels which are imparted to the patient. In Cuba, there are not reported values of that doses levels for typical CT studies. The National Control Center for Medical Devices has been developing for several years investigations for knowing the guidance doses levels for different examinations in radiodiagnosis, taking into account the recommendations made for The International Basic Safety Standards, which have been adopted in Cuba. This paper presents an study of imparted doses for typical head examinations in 10 CT scanners (6 are helical and 3 axial technology). Values of CTDI, CTDIw (weighed) and nCTDIw (weighted and normalized) were calculated. The relation between CTDI at surface and CTDI in the center of the phantom for the highest slice width was calculated for each CT scanner. Others parameters, such as CT number and its special uniformity, noise, contrast scale, sensibility profiles, MTF evaluation, table movement and alignment between lasers and radiation field, have also obtained. These parameters were evaluated by means of the manufacturer's phantom (Siemens). (author)

  20. Exploring different forest definitions and their impact on developing REDD+ reference emission levels: A case study for Indonesia

    NARCIS (Netherlands)

    Romijn, J.E.; Ainembabazi, J.H.; Wijaya, A.; Herold, M.; Angelsen, A.; Verchot, L.; Murdiyarso, D.

    2013-01-01

    Developing countries participating in the mitigation mechanism of reducing emissions from deforestation and forest degradation and the role of conservation, sustainable management of forests and enhancement of forest carbon stocks (REDD+), need to determine a national forest reference emission level

  1. Computer-aided pulmonary nodule detection. Performance of two CAD systems at different CT dose levels

    International Nuclear Information System (INIS)

    Hein, Patrick Alexander; Rogalla, P.; Klessen, C.; Lembcke, A.; Romano, V.C.

    2009-01-01

    Purpose: To evaluate the impact of dose reduction on the performance of computer-aided lung nodule detection systems (CAD) of two manufacturers by comparing respective CAD results on ultra-low-dose computed tomography (ULD-CT) and standard dose CT (SD-CT). Materials and Methods: Multi-slice computed tomography (MSCT) data sets of 26 patients (13 male and 13 female, patients 31 - 74 years old) were retrospectively selected for CAD analysis. Indication for CT examination was staging of a known primary malignancy or suspected pulmonary malignancy. CT images were consecutively acquired at 5 mAs (ULD-CT) and 75 mAs (SD-CT) with 120kV tube voltage (1 mm slice thickness). The standard of reference was determined by three experienced readers in consensus. CAD reading algorithms (pre-commercial CAD system, Philips, Netherlands: CAD-1; LungCARE, Siemens, Germany: CAD-2) were applied to the CT data sets. Results: Consensus reading identified 253 nodules on SD-CT and ULD-CT. Nodules ranged in diameter between 2 and 41 mm (mean diameter 4.8 mm). Detection rates were recorded with 72% and 62% (CAD-1 vs. CAD-2) for SD-CT and with 73% and 56% for ULD-CT. Median also positive rates per patient were calculated with 6 and 5 (CAD-1 vs. CAD-2) for SD-CT and with 8 and 3 for ULD-CT. After separate statistical analysis of nodules with diameters of 5 mm and greater, the detection rates increased to 83% and 61% for SD-CT and to 89% and 67% for ULD-CT (CAD-1 vs. CAD-2). For both CAD systems there were no significant differences between the detection rates for standard and ultra-low-dose data sets (p>0.05). Conclusion: Dose reduction of the underlying CT scan did not significantly influence nodule detection performance of the tested CAD systems. (orig.)

  2. Screening level dose assessment of aquatic biota downstream of the Marcoule nuclear complex in southern France.

    Science.gov (United States)

    St-Pierre, S; Chambers, D B; Lowe, L M; Bontoux, J G

    1999-09-01

    Aquatic biota in the Rhone River downstream of the Marcoule nuclear complex in France are exposed to natural sources of radiation and to radioactivity released from the Marcoule complex. A simple conservative screening level model was used to estimate the range of concentrations in aquatic media (water, sediments, and aquatic organisms) of both artificial and natural radionuclides and the consequent absorbed (whole body) dose rates for aquatic organisms. Five categories of aquatic organisms were studied, namely, submerged aquatic plants (phanerogam), non-bottom-feeding fish, bottom-feeding fish, mollusca, and fish-eating birds. The analysis was based on the radionuclide concentrations reported in four consecutive annual radioecological monitoring reports published by French agencies with nuclear regulatory responsibilities. The results of this assessment were used to determine, qualitatively, the magnitude of any potential health impacts on each of the five categories of aquatic organisms studied. The range of dose rate estimates ranged over three orders of magnitude, with maximum dose rates estimated to be in the order of 1 to 10 microGy h(-1). These maximum dose rates are a factor 40 or more below the international guideline intended to ensure the protection of aquatic populations (about 400 microGy h(-1)), and a factor ten or more below the level which may trigger the need for a more detailed evaluation of potential ecological consequences to the exposed populations (about 100 microGy h(-1)). As a result, chronic levels of radioactivity, artificial and natural, measured in aquatic media downstream of Marcoule are unlikely to result in adverse health impacts on the categories and species of aquatic organisms studied. Thus, based on the screening level analysis discussed in this paper, a more detailed evaluation of the dose rates does not appear to be warranted.

  3. The cost and benefit analysis of a contaminated area remediation: case study of dose level selection

    International Nuclear Information System (INIS)

    Lauria, D.C.

    2006-01-01

    In recent years there has been an increasing awareness of the radiological impact of non-nuclear industries that extract and/or process ores and minerals containing naturally occurring radioactive material (NORM). Without radiological rules, these industrial activities may result in significant radioactive contamination of installations and sites. Depending on the potential hazardous to the environment and public health, the radioactive contaminated sites may require remediation. The extent of the site cleanup is a function of the size, localization, complexity, potential risks and on possible future uses envisioned for the site. Since worker and public health, public anxiety and economics factors are involved; the selection of an appropriate dose level can be quite complicated. This paper discusses the selection of a dose level criterion to remedy a site, which was contaminated by wastes from monazite processing. The site is located in the Sao Paulo city; the most densely populated Brazilian City. In its 60,000 square meters of area, a preliminary survey showed contaminated zones covering an area of 6,500 square meters. In some places, contamination was found below the superficial layer of the soil, being the radionuclide vertical distribution not uniform. The 228 Ra soil activity concentration reached values up to 33,000 Bq/kg while those for 226 Ra reached values up to 6,700 Bq/kg. Based on pathway analysis model and considering both the current land use and a hypothetical residential scenario, the residual contamination levels of radionuclides in soil have been derived for dose values of 10 mSv/y (dose level for intervention), 5 mSv/y, 3 mSv/y, 1 mSv/y (dose limit for practices) and 0.3 mSv/y (dose constraint for practices). An optimized value o f annual dose of about 5 mSv/y would be a good option for intervention level, but taking into account the public concern and anxiety, the site location and size, and the remediation costs, it is suggested the

  4. The cost and benefit analysis of a contaminated area remediation: case study of dose level selection

    Energy Technology Data Exchange (ETDEWEB)

    Lauria, D.C. [Instituto de Radioproteccion e Dosimetria- IRD/CNEN, Av. Salvador Allende s/n, Barra de Tijuca, Rio de Janeiro- RJ (Brazil)]. e-mail: dejanira@ird.gov.br

    2006-07-01

    In recent years there has been an increasing awareness of the radiological impact of non-nuclear industries that extract and/or process ores and minerals containing naturally occurring radioactive material (NORM). Without radiological rules, these industrial activities may result in significant radioactive contamination of installations and sites. Depending on the potential hazardous to the environment and public health, the radioactive contaminated sites may require remediation. The extent of the site cleanup is a function of the size, localization, complexity, potential risks and on possible future uses envisioned for the site. Since worker and public health, public anxiety and economics factors are involved; the selection of an appropriate dose level can be quite complicated. This paper discusses the selection of a dose level criterion to remedy a site, which was contaminated by wastes from monazite processing. The site is located in the Sao Paulo city; the most densely populated Brazilian City. In its 60,000 square meters of area, a preliminary survey showed contaminated zones covering an area of 6,500 square meters. In some places, contamination was found below the superficial layer of the soil, being the radionuclide vertical distribution not uniform. The {sup 228} Ra soil activity concentration reached values up to 33,000 Bq/kg while those for {sup 226} Ra reached values up to 6,700 Bq/kg. Based on pathway analysis model and considering both the current land use and a hypothetical residential scenario, the residual contamination levels of radionuclides in soil have been derived for dose values of 10 mSv/y (dose level for intervention), 5 mSv/y, 3 mSv/y, 1 mSv/y (dose limit for practices) and 0.3 mSv/y (dose constraint for practices). An optimized value o f annual dose of about 5 mSv/y would be a good option for intervention level, but taking into account the public concern and anxiety, the site location and size, and the remediation costs, it is suggested

  5. Design of shared unit-dose drug distribution network using multi-level particle swarm optimization.

    Science.gov (United States)

    Chen, Linjie; Monteiro, Thibaud; Wang, Tao; Marcon, Eric

    2018-03-01

    Unit-dose drug distribution systems provide optimal choices in terms of medication security and efficiency for organizing the drug-use process in large hospitals. As small hospitals have to share such automatic systems for economic reasons, the structure of their logistic organization becomes a very sensitive issue. In the research reported here, we develop a generalized multi-level optimization method - multi-level particle swarm optimization (MLPSO) - to design a shared unit-dose drug distribution network. Structurally, the problem studied can be considered as a type of capacitated location-routing problem (CLRP) with new constraints related to specific production planning. This kind of problem implies that a multi-level optimization should be performed in order to minimize logistic operating costs. Our results show that with the proposed algorithm, a more suitable modeling framework, as well as computational time savings and better optimization performance are obtained than that reported in the literature on this subject.

  6. Effect of low dose ionizing radiation on Bcl-2 transcription level of Peyer's patches in mouse

    International Nuclear Information System (INIS)

    Liu Jiamei; Chen Dong; Zheng Yongchen; Liu Shuzheng

    2001-01-01

    Objective: To study the effect of whole body irradiation (WBI) with different doses of X-rays on apoptosis in cells of mouse Peyer's patches and its molecular mechanism. Methods: RT-PCR was used to detect the changes of Bcl-2 transcription level. Agarose electrophoresis and flow cytometry were used to detect the changes of DNA and apoptotic bodies in Peyer's patches after WBI with different doses of X-rays. Results: The apoptotic was increased and Bcl-2 transcription level was decreased in Peyer's patches after 2 Gy X-rays. The apoptotic rate was decreased and Bcl-2 transcription level was increased in Peyer's patches after 75 mGy X-rays. Conclusion: Bcl-2 participates in the regulation of radiation-induced apoptosis in Peyer's patches

  7. Single Enteral Loading Dose of Phenobarbital for Achieving Its Therapeutic Serum Levels in Neonates

    Science.gov (United States)

    Turhan, Ali H.; Atici, Aytug; Okuyaz, Cetin; Uysal, Sercan

    2010-01-01

    Aim To investigate whether therapeutic serum drug levels may be achieved with a single enteral loading dose of phenobarbital. Methods The study was performed at the Mersin University Hospital in Turkey between April 2004 and August 2006, and included 29 newborn babies with seizure. After the acute treatment of the seizure with midazolam at a dose of 0.1 mg/kg, phenobarbital was administered by orogastric route at a loading dose of 20 mg/kg. Serum phenobarbital concentrations were measured at 0.5, 3, 6, and 12 hours after the loading. Serum phenobarbital levels between 10-30 μg/mL were considered as the therapeutic range. Results The serum phenobarbital levels reached therapeutic values in 9 (31%), 19 (66%), 21 (72%), and 23 (79%) patients at 0.5, 3, 6, and 12 hours after loading, respectively, while they did not reach therapeutic values in 6 patients (21%) after 12 hours. Four of the patients in whom there was no increase in serum phenobarbital levels had hypoxic-ischemic encephalopathy. Conclusion Enteral loading of phenobarbital can achieve therapeutic serum levels in the large majority of newborn babies with seizure and may be safely used in babies with the intact gastrointestinal tract. PMID:20564764

  8. Radiation dose of aircrews during a solar proton event without ground-level enhancement

    Directory of Open Access Journals (Sweden)

    R. Kataoka

    2015-01-01

    Full Text Available A significant enhancement of radiation doses is expected for aircrews during ground-level enhancement (GLE events, while the possible radiation hazard remains an open question during non-GLE solar energetic particle (SEP events. Using a new air-shower simulation driven by the proton flux data obtained from GOES satellites, we show the possibility of significant enhancement of the effective dose rate of up to 4.5 μSv h−1 at a conventional flight altitude of 12 km during the largest SEP event that did not cause a GLE. As a result, a new GOES-driven model is proposed to give an estimate of the contribution from the isotropic component of the radiation dose in the stratosphere during non-GLE SEP events.

  9. Preliminary results of measurement of natural environmental radiation levels and doses to population in China

    International Nuclear Information System (INIS)

    Wang Qiliang; He Miaoting; Shu Qi

    1985-01-01

    In this paper the preliminary results of measurement of natural environmental radiation levels in China with RSS-111 high pressure ionization chamber and estimated doses to population are reported. A total of 2,723 indoor locales throughout China were measured. The results showed that the average absorbed dose rates in air due to gamma radiation for indoors and outdoors were 11.0 x 10 -8 Gy.h -1 and 7.4 x 10 -8 Gy.h -1 , respectively, and those due to cosmic rays were 3.2 x 10 -8 Gy.h -1 and 3.7 x 10 -8 Gy.h -1 , respectively. The annual average effective dose equivalent to population was 919 μSv, including 630 μSv from natural gamma radiation and 289 μSv from cosmic rays

  10. Level of radon and its daughters, and internal exposure doses in Shaanxi province

    International Nuclear Information System (INIS)

    Fan Xin; Zhang Yawei; Yu Huilian

    1992-01-01

    About 4500 indoor and outdoor air samples were collected with FDT-84 sampler throughout Shaanxi Province in various seasons, and the concentrations of radon and its daughters in the air were determined with FD-3016 scintillator. Meanwhile, the diurnal, seasonal and altitudinal variation of radon and its progeny in Xi'an area were observed. The annual effective dose equivalent for individual adult resident was estimated to be 1.73 mSv·a -1 and the annual collective effective dose equivalent for the residents- in the whole province was estimated to be 5.09 ± 10 4 man.Sv·a -1 . The concentration levels and the doses are within the range of the data published in UNSCEAR reports in recent years, and all of them are in the normal range of the natural background

  11. Introducing carrying capacity-based normalisation in LCA: framework and development of references at midpoint level

    DEFF Research Database (Denmark)

    Bjørn, Anders; Hauschild, Michael Zwicky

    2015-01-01

    carrying capacity-based normalisation references. The purpose of this article is to present a framework for normalisation against carrying capacity-based references and to develop average normalisation references (NR) for Europe and the world for all those midpoint impact categories commonly included....... A literature review was carried out to identify scientifically sound thresholds for each impact category. Carrying capacities were then calculated from these thresholds and expressed in metrics identical to midpoint indicators giving priority to those recommended by ILCD. NR was expressed as the carrying...... ozone formation and soil quality were found to exceed carrying capacities several times.The developed carrying capacity-based normalisation references offer relevant supplementary reference information to the currently applied references based on society’s background interventions by supporting...

  12. Low-level lead exposure effects on spatial reference memory and working memory in rats

    Institute of Scientific and Technical Information of China (English)

    Xinhua Yang; Ping Zhou; Yonghui Li

    2009-01-01

    BACKGROUND: Studies have demonstrated that lead exposure can result in cognitive dysfunction and behavior disorders. However, lead exposure impairments vary under different experimental conditions.OBJECTIVE: To detect changes in spatial learning and memory following low-level lead exposure in rats, in Morris water maze test under the same experimental condition used to analyze lead exposure effects on various memory types and learning processes.DESIGN AND SETTING: The experiment was conducted at the Animal Laboratory, Institute of Psychology, Chinese Academy of Science between February 2005 and March 2006. One-way analysis of variance (ANOVA) and behavioral observations were performed.MATERIALS: Sixteen male, healthy, adult, Sprague Dawley rats were randomized into normal control and lead exposure groups (n = 8).METHODS: Rats in the normal control group were fed distilled water, and those in the lead exposure group were fed 250 mL of 0.05% lead acetate once per day. At day 28, all rats performed the Morris water maze test, consisting of four phases: space navigation, probe test, working memory test, and visual cue test.MAIN OUTCOME MEASURES: Place navigation in the Morris water maze was used to evaluate spatial learning and memory, probe trials for spatial reference memory, working memory test for spatial working memory, and visual cue test for non-spatial cognitive function. Perkin-Elmer Model 300 Atomic Absorption Spectrometer was utilized to determine blood lead levels in rats.RESULTS: (1) In the working memory test, the time to reach the platform remained unchanged between the control and lead exposure groups (F(1,1) = 0.007, P = 0.935). A visible decrease in escape latencies was observed in each group (P = 0.028). However, there was no significant difference between the two groups (F(1,1) = 1.869, P = 0.193). The working memory probe test demonstrated no change between the two groups in the time spent in the target quadrant during the working memory probe test

  13. Determination of indoor radon concentration levels and the associated annual effective dose rate in some Ghanaian dwellings

    International Nuclear Information System (INIS)

    Nsiah-Akoto, I.

    2010-01-01

    cancer risk increased with indoor radon concentration. The odds ratio for the present study at 95% confidence interval was 7 (CI 0.92 - 53.16). 0.13(CI 0.02 - 0.73), 0.20 (CI0.02 - 2.39), 5.5 (CI 0.88 - 34.46), 0.25 (CI 0.05 - 1.26), 0.38(CI 0.12 - 1.22) were ORs and 95% confidence interval for the previous studies respectively. Using the BEIR III model, 5 cases of lung cancer was estimated. These results show that the indoor radon level in the present study has increased tremendously as compared to the same study area 20years ago. Though most of the houses have radon activity in the range of intervention level (200-600) Bq/m3 as recommended by ICRP (1993) and the annual effective dose in the ICRP recommendations (3mSv/y-l0mSv/y), a lot more studies needs to be done to come out with a national reference level. The radon activity has not only been found to vary with the construction mode of houses but also with the ventilation conditions and the geology of the area. The results obtained also give a correlation between indoor radon levels and the associated level of risk. (au)

  14. Pregnancy and variations of carbohydrate-deficient transferrin levels measured by the candidate reference HPLC method.

    Science.gov (United States)

    Bianchi, Vincenza; Ivaldi, Alessandra; Raspagni, Alessia; Arfini, Carlo; Vidali, Matteo

    2011-01-01

    Contrasting data are available on the diagnostic accuracy of carbohydrate-deficient transferrin (CDT) during pregnancy. These differences may depend in part on how CDT was evaluated and expressed. Here, we report on variations of CDT levels in pregnant women using the high performance liquid chromatography (HPLC) candidate reference method. Alanine aminotransferase, aspartate aminotransferase, gamma-glutamyltransferase, mean corpuscular volume, serum transferrin, urine and serum ethyl glucuronide and CDT were measured in 64 women, self-reporting as non-alcohol abusers (age: median 34, IQR: 28-38), at different stages of normal pregnancy (gestational weeks: median 28, IQR: 8-33). CDT was expressed as percentage of disialotransferrin to total transferrin (%CDT). Transferrin was associated with both %CDT (r = 0.66; P pregnancy trimester (first trimester: mean 1.01% (SD 0.19); second trimester: 1.30% (SD 0.14); third trimester: 1.53% (SD 0.22); ANOVA P pregnancy trimesters (P pregnancy and CDT could be more complex. The diagnostic accuracy of CDT for detecting alcohol abuse in a legal context may be limited in pregnant women and the effect of gestational age should be considered.

  15. 1-GWh diurnal load-leveling Superconducting Magnetic Energy Storage system reference design

    International Nuclear Information System (INIS)

    Rogers, J.D.; Hassenzahl, W.V.; Schermer, R.I.

    1979-09-01

    A point reference design has been completed for a 1-GWh Superconducting Magnetic Energy Storage system. The system is for electric utility diurnal load-leveling but can also function to meet much faster power demands including dynamic stabilization. This study explores several concepts of design not previously considered in the same detail as treated here. Because the study is for a point design, optimization in all respects is not complete. This report examines aspects of the coil, the superconductor supported off of the dewar shell, the dewar shell, and its configuration and stresses, the underground excavation and construction for holding the superconducting coil and its dewar, the helium refrigeration system, the electrical converter system, the vacuum system, the guard coil, and the costs. This report is divided into two major portions. The first is a general treatment of the work and the second is seven detailed technical appendices issued as separate reports. The information presented on the aluminum stabilizer for the conductor, on the excavation, and on the converter is based upon industrial studies contracted for this work

  16. Establishment of diagnostic reference levels for dental panoramic radiography in Greece

    International Nuclear Information System (INIS)

    Manousaridis, G.; Koukorava, C.; Hourdakis, C.J.; Kamenopoulou, V.; Yakoumakis, E.; Tsiklakis, K.

    2015-01-01

    The purpose of the present study was to present the national diagnostic reference levels (DRL) established for panoramic dental examinations in Greece. The establishment of DRL, as a tool for the optimisation of radiological procedures, is a requirement of national regulations. Measurements performed by the Greek Atomic Energy Commission on 90 panoramic systems have been used for the derivation of DRL values. DRL values have been proposed for exposure settings of different patient types (child, small adult and standard adult), both for film and digital imaging. The DRLs for different patient types are grouped in three categories: children, small adults (corresponding to female) and average adults (corresponding to male). Proposed DRLs for these groups are 2.2, 3.3 and 4.1 mGy, respectively. In order to investigate the correlation of DRLs with the available imaging modalities (CR, DR and film), this parameter was taken into account. DR imaging DRL is the lowest at 3.5 mGy, CR imaging the highest at 4.2 mGy and film imaging at 3.7 mGy. In order to facilitate comparison with other studies, kerma-width product values were calculated from K i , air and field size. (authors)

  17. Reactor Emergency Action Level Monitor: Volume 2, REALM user's reference guide: Final report

    International Nuclear Information System (INIS)

    Touchton, R.A.

    1988-09-01

    A User Manual for the Reactor Emergency Action Level Monitor (REALM) expert system prototype is provided in this volume. REALM has been designed to provide expert assistance in the identification of a nuclear power plant emergency situation and the determination of its severity. REALM has been developed as an expert system which can provide sensor interpretation and situation assessment in a real-time processing environment. In its state of development at project completion, these capabilities are used in an off-line (i.e., stand-alone, desktop) fashion to provide emergency preparedness assistance in the areas of emergency classification training and emergency exercise scenario generation. REALM also serves a prototype and stepping-stone for the possible connection to the plant for on-line use. In order to distinguish the off-line system (now complete) from the on-line system (now moving from a research prototype to an installed system), the term ''REALM'' is used to indicate the on-line version, with users in the control room, technical support center, and the emergency operations facility, The off-line version is referred to as ''uREALM.''

  18. What happens at very low levels of radiation exposure ? Are the low dose exposures beneficial ?

    International Nuclear Information System (INIS)

    Deniz, Dalji

    2006-01-01

    Full text: Radiation is naturally present in our environment and has been since the birth of this planet. The human population is constantly exposed to low levels of natural background radiation, primarily from environmental sources, and to higher levels from occupational sources, medical therapy, and other human-mediated events. Radiation is one of the best-investigated hazardous agents. The biological effects of ionizing radiation for radiation protection consideration are grouped into two categories: The deterministic and the stochastic ones. Deterministic radiation effects can be clinically diagnosed in the exposed individual and occur when above a certain t hreshold a n appropriately high dose is absorbed in the tissues and organs to cause the death of a large number of cells and consequently to impair tissue or organ functions early after exposure. A clinically observable biological effect (Acute Radiation Sendromes, ARS) occurs days to months after an acute radiation dose. Stochastic radiation effects are the chronic effects of radiation result from relatively low exposure levels delivered over long periods of time. These are sort of effects that might result from occupational exposure, or to the background exposure levels. Such late effects might be the development of malignant (cancerous) disease and of the hereditary consequences. These effects may be observed many years after the radiation exposure. There is a latent period between the initial radiation exposure and the development of the biological effect. For this reason, a stochastic effect is called a Linear or Zero-Threshold (LNT) Dose-Response Effect. There is a stochastic correlation between the number of cases of cancers or genetic defects developed inside a population and the dose received by the population at relatively large levels of radiation. These changes in gene activation seem to be able to modify the response of cells to subsequent radiation exposure, termed the a daptive response

  19. Resolving the limitations of using glycine as EPR dosimeter in the intermediate level of gamma dose

    Science.gov (United States)

    Aboelezz, E.; Hassan, G. M.

    2018-04-01

    The dosimetric properties of the simplest amino acid "glycine"- using EPR technique- were investigated in comparison to reference standard alanine dosimeter. The EPR spectrum of glycine at room temperature is complex, but immediately after irradiation, it appears as a triplet hyperfine structure probably due to the dominant contribution of the (•CH2COO-) radical. The dosimetric peak of glycine is at g-factor 2.0026 ± 0.0015 and its line width is 9 G at large modulation amplitude (7 G). The optimum microwave was studied and was found to be as alanine 8 mW; the post-irradiation as well as the dose rate effects were discussed. Dosimetric peak intensity of glycine fades rapidly to be about one quarter of its original value during 20 days for dried samples and it stabilizes after that. The dose response study in an intermediate range (2-1000 Gy) reveals that the glycine SNR is about 2 times more than that of alanine pellets when measured immediately after irradiation and 4 times more than that of glycine itself after 22 days of irradiation. The effect of energy dependence was studied and interpreted theoretically by calculation of mass energy absorption coefficient. The calculated combined uncertainties for glycine and alanine are nearly the same and were found to be 2.42% and 2.33%, respectively. Glycine shows interesting dosimetric properties in the range of ionizing radiation doses investigated.

  20. The effect of dose, dose rate, route of administration, and species on tissue and blood levels of benzene metabolites

    International Nuclear Information System (INIS)

    Henderson, R.F.; Sabourin, P.J.; Bechtold, W.E.; Griffith, W.C.; Medinsky, M.A.; Birnbaum, L.S.; Lucier, G.W.

    1989-01-01

    Studies were completed in F344/N rats and B6C3F 1 mice to determine the effect of dose, dose rate, route of administration, and rodent species on formation of total and individual benzene metabolites. Oral doses of 50 mg/kg or higher saturated the capacity for benzene metabolism in both rats and mice, resulting in an increased proportion of the administered dose being exhaled as benzene. The saturating air concentration for benzene metabolism during 6-hr exposures was between 130 and 900 ppm. At the highest exposure concentration, rats exhaled approximately half of the internal dose retained at the end of the 6-hr exposure as benzene; mice exhaled only 15% as benzene. Mice were able to convert more of the inhaled benzene to metabolites than were rats. In addition, mice metabolized more of the benzene by pathways leading to the putative toxic metabolites, benzoquinone and muconaldehyde, than did rats. In both rats and mice, the effect of increasing dose, administered orally or by inhalation, was to increase the proportion of the total metabolites that were the products of detoxification pathways relative to the products of pathways leading to putative toxic metabolites. This indicates low-affinity, high-capacity pathways for detoxification and high-affinity, low-capacity pathways leading to putative toxic metabolites. If the results of rodent studied performed at high doses were used to assess the health risk at low-dose exposures to benzene, the toxicity of benzene would be underestimated

  1. The calculation of dose from external photon exposures using reference human phantoms and Monte Carlo methods. Pt. 4

    International Nuclear Information System (INIS)

    Williams, G.; Zankl, M.; Drexler, G.

    1984-12-01

    This report considers the contribution from scattered radiation to the dose to organs and tissues which lie outside the useful therapy beams. The results presented are the product of Monte Carlo studies used to determine the tissue doses due to internal scattering of the useful beams only. General cases are calculated in which central target volumes in the trunk are treated with 10 x 14 cm 2 and 14 x 14 cm 2 fields from 200 kV, Co-60, 8 MV and 25 MV therapy equipment. Target volumes in the neck are considered to be treated with 5 x 5 cm 2 fields. Different treatment plans are calculated including rotational therapy. Also two specific cases are more fully analysed, namely for Ankylosing Spondylitis and central abdomen malignant disease in the region of the head of the pancreas. The calculated organ doses are presented in tables as a percentage of the target volume dose. (orig.)

  2. Assessment of natural radioactivity concentrations and gamma dose levels around Shorapur, Karnataka

    Energy Technology Data Exchange (ETDEWEB)

    Rajesh, S.; Avinash, P.; Kerur, B. R., E-mail: kerurpbk@rediffmail.com.com [Department of Physics, Gulbarga University Kalaburagi – 585 106 India (India); Anilkumar, S. [Radiation Safety Systems Division, BARC, Mumbai - 400 085 (India)

    2015-08-28

    This study assesses the level of background radiation around Shorapur. The study region locates the western part of the Yadgir district of Karnataka. Shorapur and Shahapur talukas are mostly composed of clay, shale sandstone, granite rock and part of study area is black soil. Thirty sample locations were selected along the length and breadth of Shorapur and Shahapur taluka. Natural radionuclide activity concentrations in soil samples were determined using 4'X4' NaI (Tl) gamma spectroscopy. Outdoor gamma dose measurements in air at 1 m above ground level were determined using Rad Eye PRD survey meter. Estimated dose values are compared with the survey meter values and found to be good agreement between them and also with the data obtained from different other areas of Karnataka and India. The average values were found to be slightly higher in the present investigation.

  3. The calculation of dose from external photon exposures using reference human phantoms and Monte Carlo methods. Pt. 3

    International Nuclear Information System (INIS)

    Drexler, G.; Panzer, W.; Widenmann, L.; Williams, G.; Zankl, M.

    1984-03-01

    This report gives tables of conversion factors for the calculation of organ doses from technical parameters of typical radiographic techniques. These conversion factors were calculated using a male and a female mathematical human phantom and an efficient Monte Carlo programme that determines the mean organ doses from the energy deposited in each organ. Each diagnostic X-ray examination is studied using three X-ray spectra resulting from three different high tension values. The conversion factors per unit entrance air dose in free air are given for sixteen organs and for the entrance and exit surface skin doses. The tables are actually valid only for the given parameters such as phantom dimensions, source-to-skin distance, projection and X-ray quality. This, of course, gives rise to some uncertainty when dealing with the individual technique and patient. The uncertainty in organ dose of adult patients, however, should not be very large, if the calculation is based on a similar geometry, and before all, on the actually administered entrance air dose in the selected high tension range according to the patient parameters. (orig.)

  4. Estimation of natural radiation background level and population dose in China

    International Nuclear Information System (INIS)

    Pan Ziqiang

    1992-01-01

    The authors describe in general the natural radiation background level in China, and based on available data present an estimated annual effective dose equivalent of the population to natural radiation that is some 2.3 mSv, of which about 0.54 mSv is from original γ radiation and about 0.8 mSv from radon and its short-lived daughters

  5. Comparison BIPM.RI(I)-K8 of high dose-rate Ir-192 brachytherapy standards for reference air kerma rate of the PTB and the BIPM

    International Nuclear Information System (INIS)

    Kessler, C.; Allisy-Roberts, P.J.; Selbach, H.J.

    2015-01-01

    An indirect comparison of the standards for reference air kerma rate (RAKR) for 192 Ir high dose rate (HDR) brachytherapy sources of the Physikalisch-Technische Bundesanstalt (PTB), Germany, and of the Bureau International des Poids et Mesures (BIPM) was carried out at the PTB in September 2011. The comparison result, based on the calibration coefficients for a transfer standard and expressed as a ratio of the PTB and the BIPM standards for reference air kerma rate, is 1.0003 with a combined standard uncertainty of 0.0099. (authors)

  6. Evaluation of multiple scan average dose (MSAD) levels in computerized tomography in Minas Gerais state, Brazil; Avaliacao dos niveis de dose media em cortes multiplos (MSAD) em tomografia computadorizada no estado de Minas Gerais

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, Thessa C., E-mail: alonso@cdtn.br [Centro de Desenvolvimento de Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Vieira, Leandro de A.; Barbosa, Nayra V.; Oliveira, Jeyselaine R. de; Cesar, Adriana C.Z. [Secretaria de Vigilancia Sanitaria de Minas Gerais, Belo Horizonte, MG (Brazil); Silva, Teogenes A. da [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear. Programa de Ciencias e Tecnicas Nucleares

    2014-07-01

    Computed Tomography (CT) grows every year and is a diagnostic method that has revolutionized radiology with advances in procedures for obtaining image. However, the indiscriminate use of this method generates relatively high doses in patients. The diagnostic reference levels (DRLs) is a practical tool to promote the evaluation of existing protocols. The optimization and the periodic review of the protocols are important to balance the risk of radiation. The present study aims to conduct a survey of levels of MSAD of Minas Gerais following the procedures recommended by current Brazilian law. (author)

  7. Actual survey of dose evaluation method for standardization of radiation therapy techniques. With special reference to display method of radiation doses

    International Nuclear Information System (INIS)

    Kumagai, Kozo; Yoshiura, Takao; Izumi, Takashi; Araki, Fujio; Takada, Takuo; Jingu, Kenichi.

    1994-01-01

    This report presents the results of questionnaire survey for actual conditions of radiation therapy, which was conducted with the aim of establishing the standardization of radiation therapy techniques. Questionnaires were sent to 100 facilities in Japan, and 86 of these answered, consisting of 62 university hospitals, 2 national hospitals, 14 cancer centers, 4 prefectural or municipal hospitals, and 4 other hospitals. In addition to electron beam therapy, the following typical diseases for radiation therapy were selected as standard irradiation models: cancers of the larynx, esophagus, breast, and uterine cervix, and malignant lymphomas. According to these models, questionnaire results are analyzed in terms of the following four items: (1) irradiation procedures, (2) energy used for radiotherapy, (3) the depth for calculating target absorption doses, and (4) points for displaying target absorption doses. (N.K.)

  8. Application of geometry correction factors for low-level waste package dose measurements. Revision 1

    International Nuclear Information System (INIS)

    Chandler, M.C.; Parish, B.

    1995-01-01

    Plans are to determine the Cs-137 content of low-level waste packages generated in High-Level Waste by measuring the radiation level at a specified distance from the package with a hand-held radiation instrument. The measurement taken at this specified distance, either 3 or 5 feet, is called the far-field measurement. This report documents a method for adjusting the gamma exposure rate (mR/hr) reading used in dose-to-curie determinations when the far-field measurement equals the background reading. This adjustment is necessary to reduce the conservatism resulting from using a minimum detection limit exposure rate for the dose-to-curie determination for the far-field measurement position. To accomplish this adjustment, the near-field (5 cm) measurement is multiplied by a geometry correction factor to obtain an estimate of the far field exposure rate (which is below instrument sensitivity). This estimate of the far field exposure rate is used to estimate the Cs-137 curie content of the package. This report establishes the geometry correction factors for the dose-to-curie determination when the far-field gamma exposure measurement equals the background reading. This report also provides a means of demonstrating compliance to 1S Manual requirements for exposure rate readings at different locations from waste packages while specifying only two measurement positions. This demonstration of compliance is necessary to minimize the number of locations exposure rate measurements that are required, i.e., ALARA

  9. Cytogenetic damage at low doses and the problem of bioindication of chronic low level radiation exposure

    International Nuclear Information System (INIS)

    Geras'kin, S.A.; Dikarev, V.G.; Nesterov, E.B.; Vasiliev, D.V.; Dikareva, N.S.

    2000-01-01

    The analysis undertaken by us of the experimentally observed cellular responses to low dose irradiation has shown that the relationship between the yield of induced cytogenetic damage and radiation dose within low dose range is non-linear and universal in character. Because of the relationship between the yield of cytogenetic damage and dose within low dose range is non-linear, the aberration frequency cannot be used in biological dosimetry in the most important in terms of practical application case. The cytogenetic damage frequency cannot be used in biological dosimetry also because of the probability of synergistic and antagonistic interaction effects of the different nature factors simultaneously acting on test-object in real conditions is high within low dose (concentration) range. In our experimental study of the regularities in the yield of structural mutations in conditions of combined influence of ionizing radiation, heavy metals and pesticides it was found that synergistic and antagonistic effects are mainly induced in conditions of combined action of low exposure injuring agents. Experiments on agricultural plants were carried out in 1986-1989 at the 30-km zone around Chernobyl NPP. It was shown that chronic low dose exposure could cause an inheritable destabilization of genetic structures expressing in increase of cytogenetic damage and yield karyotypic variability in offspring's of irradiated organisms. Obviously exactly this circumstance is the reason of the phenomenon found in our researches of significant time delay of cytogenetic damage reduction rate from radioactive pollution reduction rate from time past from the accident moment. Research of cytogenetic damage of reproductive (seeds) and vegetative (needles) plant organs of the Pinus sylvestris tree micropopulations growing in contrast by radioactive pollution level sites of the 30-km ChNPP zone and also in the vicinity of the industrial plant > for processing and temporary storage of

  10. Effect of Exposure to Pill Contraceptive Low-dose Levels of Homocysteine and Nitric Oxide in Healthy Women

    Directory of Open Access Journals (Sweden)

    A Dehghani

    2016-07-01

    Full Text Available Introduction: Cardiovascular disease is one of the public health priorities. Consumption of oral contraceptives increase the risk of cardiovascular disease and it still remains a concern. This study aimed to investigate the effect of exposure on pill contraceptive low-dose  levels on homocysteine and nitric oxide. methods: In this cohort ( retrospective+ prospective study, 100 women with normal menstrual cycle aged betwen 20-35 years old refered to health care centers of Yazd, Iran in 2015.  This study was conducted through face to face interviews by the researcher who asked for demographic and anthropometric characteristics. Anthropometic indices  was measured and the levels of homosysteine and nitric oxide was determined. The data were analyzed using t-test, chi- square test and ANOVA by SPSS 21. Results: The mean and standard deviation of homocysteine levels in the exposed group acompared to non-exposed group were (3/848±2/357 μmol/L and (3/284±1/616 μmol/L as well as the mean and standard deviation of nitric oxide in the exposed group were (p-value=0/41 and (181/360±90/44μM and in the non-exposed group were (162/654±90/913 μM and (p-value=0/29 , respectively.According to these results, there was not found any statistical significant  difference among these results. Conclusion: Taking low dose oral contraceptives in healthy women did not change any differences in homocysteine and nitric oxide levels as a modifiable risk factors for cardiovascular disease.

  11. The evaluation of radiation level and dose of workers in Guangzhou metro line 1

    International Nuclear Information System (INIS)

    Zhang Lin; Hu Canyun; Meng Xiaolian; He Zhan

    2006-01-01

    Objective: To find out the level of radiation and effective dose of workers in Guangzhou Metro line 1. Methods: In metro stations, external Gamma-ray exposure rates were obtained by FD-71A radiance measurer, 222 Rn and 220 Rn concentrations were obtained by using Rn-Tn solid state nuclear track detectors developed by The National Institute for Radiological Protection and Nuclear Safety, Chinese Centre for Disease Control. The annual Effective dose from Gamma, 222 Rn and 220 Rn were calculated. Results: The external Gamma-ray exposure average rate is 17.74 x 10 -8 Gy/h. The average concentration of 222 Rn is 59.8 Bq/m 3 . The average concentration of 220 Rn is 32.1 Bq/m 3 . The total annual effective dose from Gamma, 222 Rn and 220 Rn is 2.878 mSv/a. Conclusion: In the stations of Guangzhou in metro line 1, no more effective radiation dose to the workers has measured. (authors)

  12. Comparative study of reference points by dosimetric analyses for late complications after uniform external radiotherapy and high-dose-rate brachytherapy for cervical cancer

    International Nuclear Information System (INIS)

    Chen, S.-W.; Liang, J.-A.; Yeh, L.-S.; Yang, S.-N.; Shiau, A.-C.; Lin, F.-J.

    2004-01-01

    Purpose: This study aimed to correlate and compare the predictive values of rectal and bladder reference doses of uniform external beam radiotherapy without shielding and high-dose-rate intracavitary brachytherapy (HDRICB) with late sequelae in patients with uterine cervical cancer. Methods and materials: Between September 1992 and December 1998, 154 patients who survived more than 12 months after treatment were studied. Initially, they were treated with 10-MV X-rays (44 to 45 Gy/22 to 25 fractions over 4 to 5 weeks) to the whole pelvis, after which HDRICB was performed using 192 Ir remote afterloading at 1-week intervals for 4 weeks. The standard prescribed dose for each HDRICB was 6.0 Gy to point A. Patient- and treatment-related-factors were evaluated for late rectal complications using logistic regression modeling. Results: The probability of rectal complications showed better correlation of dose-response with increasing total ICRU (International Committee on Radiotherapy Units and Measurements) rectal dose. Multivariate logistic regression demonstrated a high risk of late rectal sequelae in patients who developed rectal complications (p 0.0001;relative risk, 15.06;95% CI, 2.89∼43.7) and total ICRU rectal dose greater than 16 Gy (p = 0.02;relative risk, 2.07;95% CI, 1.13∼4.55). The high risk factors for bladder complications were seen in patients who developed rectal complications (p = 0.0001;relative risk, 15.2;95% CI, 2.81∼44.9) and total ICRU bladder dose greater than 24 Gy (p = 0.02;relative risk, 8.93;95% CI, 1.79∼33.1). Conclusion: This study demonstrated the predictive value of ICRU rectal and bladder reference dosing in HDRICB for patients receiving uniform external beam radiation therapy without central shielding. Patients who had a total ICRU rectal dose greater than 16 Gy, or a total ICRU bladder dose over 24 Gy, were at risk of late sequelae

  13. Optimization of hybrid iterative reconstruction level and evaluation of image quality and radiation dose for pediatric cardiac computed tomography angiography

    International Nuclear Information System (INIS)

    Yang, Lin; Liang, Changhong; Zhuang, Jian; Huang, Meiping; Liu, Hui

    2017-01-01

    Hybrid iterative reconstruction can reduce image noise and produce better image quality compared with filtered back-projection (FBP), but few reports describe optimization of the iteration level. We optimized the iteration level of iDose"4 and evaluated image quality for pediatric cardiac CT angiography. Children (n = 160) with congenital heart disease were enrolled and divided into full-dose (n = 84) and half-dose (n = 76) groups. Four series were reconstructed using FBP, and iDose"4 levels 2, 4 and 6; we evaluated subjective quality of the series using a 5-grade scale and compared the series using a Kruskal-Wallis H test. For FBP and iDose"4-optimal images, we compared contrast-to-noise ratios (CNR) and size-specific dose estimates (SSDE) using a Student's t-test. We also compared diagnostic-accuracy of each group using a Kruskal-Wallis H test. Mean scores for iDose"4 level 4 were the best in both dose groups (all P < 0.05). CNR was improved in both groups with iDose"4 level 4 as compared with FBP. Mean decrease in SSDE was 53% in the half-dose group. Diagnostic accuracy for the four datasets were in the range 92.6-96.2% (no statistical difference). iDose"4 level 4 was optimal for both the full- and half-dose groups. Protocols with iDose"4 level 4 allowed 53% reduction in SSDE without significantly affecting image quality and diagnostic accuracy. (orig.)

  14. Optimization of hybrid iterative reconstruction level and evaluation of image quality and radiation dose for pediatric cardiac computed tomography angiography

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Lin; Liang, Changhong [Southern Medical University, Guangzhou (China); Guangdong Academy of Medical Sciences, Dept. of Radiology, Guangdong General Hospital, Guangzhou (China); Zhuang, Jian [Guangdong Academy of Medical Sciences, Dept. of Cardiac Surgery, Guangdong Cardiovascular Inst., Guangdong Provincial Key Lab. of South China Structural Heart Disease, Guangdong General Hospital, Guangzhou (China); Huang, Meiping [Guangdong Academy of Medical Sciences, Dept. of Radiology, Guangdong General Hospital, Guangzhou (China); Guangdong Academy of Medical Sciences, Dept. of Catheterization Lab, Guangdong Cardiovascular Inst., Guangdong Provincial Key Lab. of South China Structural Heart Disease, Guangdong General Hospital, Guangzhou (China); Liu, Hui [Guangdong Academy of Medical Sciences, Dept. of Radiology, Guangdong General Hospital, Guangzhou (China)

    2017-01-15

    Hybrid iterative reconstruction can reduce image noise and produce better image quality compared with filtered back-projection (FBP), but few reports describe optimization of the iteration level. We optimized the iteration level of iDose{sup 4} and evaluated image quality for pediatric cardiac CT angiography. Children (n = 160) with congenital heart disease were enrolled and divided into full-dose (n = 84) and half-dose (n = 76) groups. Four series were reconstructed using FBP, and iDose{sup 4} levels 2, 4 and 6; we evaluated subjective quality of the series using a 5-grade scale and compared the series using a Kruskal-Wallis H test. For FBP and iDose{sup 4}-optimal images, we compared contrast-to-noise ratios (CNR) and size-specific dose estimates (SSDE) using a Student's t-test. We also compared diagnostic-accuracy of each group using a Kruskal-Wallis H test. Mean scores for iDose{sup 4} level 4 were the best in both dose groups (all P < 0.05). CNR was improved in both groups with iDose{sup 4} level 4 as compared with FBP. Mean decrease in SSDE was 53% in the half-dose group. Diagnostic accuracy for the four datasets were in the range 92.6-96.2% (no statistical difference). iDose{sup 4} level 4 was optimal for both the full- and half-dose groups. Protocols with iDose{sup 4} level 4 allowed 53% reduction in SSDE without significantly affecting image quality and diagnostic accuracy. (orig.)

  15. Investigation of cortisole levels at exposure to small doses of ionizing radiation at working out and identification of mathematical model

    International Nuclear Information System (INIS)

    Yishkhanova, M.A.; Anyipko, O.B.; Myitryajeva, N.A.; Gubs'kij, V.Yi.

    1993-01-01

    The authors report primary data to create the model of animals irradiation in the doses of 0.13 - 1.15 Gy during 0.5 - 42 days. Dependence of blood cortisole level on the dose of irradiation (0.13 - 1.15 Gy) during 0.5 - 1.5 days was determined. The dependence of cortisole level on the doses and the length of the period after the irradiation was found to be a complicated function. Within the dose range of 0.13 - 1.15 Gy during 0.5 -1.5 days cortisole level does not depend on the dose value. The study of influence of the terms duration on cortisole level has showed that within 0.5 - 1.5 days it increases irrespective of the dose of irradiation, and within 4 - 42 days it decreases

  16. Effect of ultra-low doses, ASIR and MBIR on density and noise levels of MDCT images of dental implant sites.

    Science.gov (United States)

    Widmann, Gerlig; Al-Shawaf, Reema; Schullian, Peter; Al-Sadhan, Ra'ed; Hörmann, Romed; Al-Ekrish, Asma'a A

    2017-05-01

    Differences in noise and density values in MDCT images obtained using ultra-low doses with FBP, ASIR, and MBIR may possibly affect implant site density analysis. The aim of this study was to compare density and noise measurements recorded from dental implant sites using ultra-low doses combined with FBP, ASIR, and MBIR. Cadavers were scanned using a standard protocol and four low-dose protocols. Scans were reconstructed using FBP, ASIR-50, ASIR-100, and MBIR, and either a bone or standard reconstruction kernel. Density (mean Hounsfield units [HUs]) of alveolar bone and noise levels (mean standard deviation of HUs) was recorded from all datasets and measurements were compared by paired t tests and two-way ANOVA with repeated measures. Significant differences in density and noise were found between the reference dose/FBP protocol and almost all test combinations. Maximum mean differences in HU were 178.35 (bone kernel) and 273.74 (standard kernel), and in noise, were 243.73 (bone kernel) and 153.88 (standard kernel). Decreasing radiation dose increased density and noise regardless of reconstruction technique and kernel. The effect of reconstruction technique on density and noise depends on the reconstruction kernel used. • Ultra-low-dose MDCT protocols allowed more than 90 % reductions in dose. • Decreasing the dose generally increased density and noise. • Effect of IRT on density and noise varies with reconstruction kernel. • Accuracy of low-dose protocols for interpretation of bony anatomy not known. • Effect of low doses on accuracy of computer-aided design models unknown.

  17. Basic Restriction and Reference Level in Anatomically-based Japanese Models for Low-Frequency Electric and Magnetic Field Exposures

    Science.gov (United States)

    Takano, Yukinori; Hirata, Akimasa; Fujiwara, Osamu

    Human exposed to electric and/or magnetic fields at low frequencies may cause direct effect such as nerve stimulation and excitation. Therefore, basic restriction is regulated in terms of induced current density in the ICNIRP guidelines and in-situ electric field in the IEEE standard. External electric or magnetic field which does not produce induced quantities exceeding the basic restriction is used as a reference level. The relationship between the basic restriction and reference level for low-frequency electric and magnetic fields has been investigated using European anatomic models, while limited for Japanese model, especially for electric field exposures. In addition, that relationship has not well been discussed. In the present study, we calculated the induced quantities in anatomic Japanese male and female models exposed to electric and magnetic fields at reference level. A quasi static finite-difference time-domain (FDTD) method was applied to analyze this problem. As a result, spatially averaged induced current density was found to be more sensitive to averaging algorithms than that of in-situ electric field. For electric and magnetic field exposure at the ICNIRP reference level, the maximum values of the induced current density for different averaging algorithm were smaller than the basic restriction for most cases. For exposures at the reference level in the IEEE standard, the maximum electric fields in the brain were larger than the basic restriction in the brain while smaller for the spinal cord and heart.

  18. The establishment of local diagnostic reference levels in endoscopic retrograde cholangiopancreatography: a practical tool for the optimisation and for quality assurance management

    International Nuclear Information System (INIS)

    Saukko, E.; Henner, A.; Nieminen, M.T.; Ahonen, S.-M.

    2017-01-01

    Fluoroscopic procedures are an area of special concern in relation to radiation protection. The aim of this study was to describe the current level of patient radiation doses in endoscopic retrograde cholangiopancreatography (ERCP) collected from a single centre, as well as to establish and review local diagnostic reference levels (DRLs) in ERCP. A total of 100 patients' radiation doses in ERCP were recorded, and the third-quartile method was adopted to establish local DRLs for ERCP. The mean dose area product (DAP) was 2.05 Gy cm 2 , fluoroscopy time (FT) 1.7 min and the number of images was 3. The proposed local DRLs for ERCP were 3.00 Gy cm 2 and 3.0 min. Local DRLs were reviewed in a sample of 25 patients 5 y after they had been established. In reviewing data, the averages of DAP and FT were below the local DRLs. Local DRLs help in the optimisation process of fluoroscopic procedures and guides to a good clinical practice. (authors)

  19. Sci-Fri AM: MRI and Diagnostic Imaging - 02: Quality Improvement: Diagnostic Reference Levels for Interior Health CT exams – L-Spine, Chest/Abdomen/pelvis, Abdomen/Pelvis, Head

    International Nuclear Information System (INIS)

    Bjarnason, Thorarin

    2016-01-01

    Diagnostic Reference Levels are used to optimize patient dose and image quality in the clinical setting. It is assumed that the majority of exams are of diagnostic quality, or the radiologists would request protocol adjustments. By investigating the dose indicator distributions from all scanners, the upper DRL can be set to the 75th percentile of the distribution and a lower DRL can be set to the 10th percentile. Scanners using doses consistently outside the upper/lower DRL range can be adjusted accordingly. 11 CT scanners, all contributing to the American College of Radiology Dose Index Registry (ACR DIR) were used in this study. Dose indicator data were compiled from the ACR DIR data and local DRLs established. Scanners with median doses outside the upper/lower DRL were followed-up with. Using effective dose and exam volumes, collective dose was determined before and after protocol adjustments to evaluate the effect of this quality improvement effort. The quality initiative is complete for L-spine and Chest/Abdomen/Pelvis exams and only initial surveys were completed for Head and Abdomen/Pelvis examsg. Median Scanner Dose reductions were 8.8 and 4.9 % for L-spine and Chest/Abdomen/Pelvis exams, respectively, resulting with collective dose reductions of 0.7 and 3.2 person•Sv/yr. Follow-up is ongoing for Abdomen/Pelvis and Head exams.

  20. Sci-Fri AM: MRI and Diagnostic Imaging - 02: Quality Improvement: Diagnostic Reference Levels for Interior Health CT exams – L-Spine, Chest/Abdomen/pelvis, Abdomen/Pelvis, Head

    Energy Technology Data Exchange (ETDEWEB)

    Bjarnason, Thorarin [Diagnostic Imaging / Interior Health, Mathematics, Statistics, Physics & Computer Science / UBCO (Canada); Radiology / UBC (Canada)

    2016-08-15

    Diagnostic Reference Levels are used to optimize patient dose and image quality in the clinical setting. It is assumed that the majority of exams are of diagnostic quality, or the radiologists would request protocol adjustments. By investigating the dose indicator distributions from all scanners, the upper DRL can be set to the 75th percentile of the distribution and a lower DRL can be set to the 10th percentile. Scanners using doses consistently outside the upper/lower DRL range can be adjusted accordingly. 11 CT scanners, all contributing to the American College of Radiology Dose Index Registry (ACR DIR) were used in this study. Dose indicator data were compiled from the ACR DIR data and local DRLs established. Scanners with median doses outside the upper/lower DRL were followed-up with. Using effective dose and exam volumes, collective dose was determined before and after protocol adjustments to evaluate the effect of this quality improvement effort. The quality initiative is complete for L-spine and Chest/Abdomen/Pelvis exams and only initial surveys were completed for Head and Abdomen/Pelvis examsg. Median Scanner Dose reductions were 8.8 and 4.9 % for L-spine and Chest/Abdomen/Pelvis exams, respectively, resulting with collective dose reductions of 0.7 and 3.2 person•Sv/yr. Follow-up is ongoing for Abdomen/Pelvis and Head exams.

  1. Radiation doses in alternative commercial high-level waste management systems

    International Nuclear Information System (INIS)

    Schneider, K.J.; Pelto, P.J.; Lavender, J.C.; Daling, P.M.; Fecht, B.A.

    1986-01-01

    In the commercial high-level waste management system, potential changes are being considered that will augment the benefits of an integral monitored retrievable storage (MRS) facility. The US Department of Energy (DOE) has recognized that alternative options could be implemented in the authorized waste management system (i.e., without an integral MRS facility) to potentially achieve some of the same beneficial effects of the integral MRS system. This paper summarizes those DOE-sponsored analyses related to radiation doses resulting from changes in the waste management system. This report presents generic analyses of aggregated radiation dose impacts to the public and occupational workers, of nine postulated changes in the operation of a spent-fuel management system without an MRS facility

  2. Comparison of predicted versus measured dose rates for low-level radioactive waste cask shipments

    International Nuclear Information System (INIS)

    Macher, Martin S.

    1992-01-01

    Shippers of low-level radioactive waste must select casks which will provide sufficient shielding to keep dose rates below the federal limit of 10 mr/hr at 2 meters from the vehicle. Chem-Nuclear Systems, Inc. uses a cask selection methodology which is based on shielding analysis code predictions with an additional factor of safety applied to compensate for inhomogeneities in the waste, uncertainties in waste characterization, and inaccuracy in the calculational methods. This proven cask selection methodology is explained and suggested factors of safety are presented based on comparisons of predicted and measured dose rates. A safety factor of 2 is shown to be generally appropriate for relatively homogeneous waste and a safety factor of between 3 and 4 is shown to be generally appropriate for relatively inhomogeneous wastes. (author)

  3. The preparation and characterization of a loess sediment reference material for QC/QA of the annual radiation dose determination in luminescence dating

    International Nuclear Information System (INIS)

    De Corte, F.; De Wispelaere, A.; Vandenberghe, D.; Hossain, S.M.; Van den haute, P.

    2005-01-01

    Of crucial importance for obtaining reliable results in the luminescence dating of sediments, is the accurate and precise assessment of both the palaeodose and the annual radiation dose [cf the age equation: luminescence-age (ka) = palaeodose (Gray)/annual radiation dose (Gray.ka -1 )]. Clearly, for QC/QA of the annual radiation dose determination, a sediment reference material - not readily available up to now - would be highly useful. Therefore, in the present work a loess sediment was prepared and characterized with well-defined K, Th and U contents (the radiation dose being built up mainly by 40 K, and by 232 Th and 235,238 U and their decay daughters) and - otherwise expressed - alpha, beta, gamma and total radiation dose-rates. The material, a fine-grained aeolian loess sediment deposited in the Young-Pleistocene (Weichselian), a part of the Quaternary, was collected at Volkegem, Belgium. At the sampling site, NaI(Tl) field gamma-ray spectrometry was performed, yielding - via comparison with the 'Heidelberg calibration block' - concentrations (wet loess weight) for K, Th and U. About 14 kg material was brought to the laboratory and kept for ∼1 week at 110 degree C until constant weight (water content ≅14%). Then, the dried loess was subject to agate ball milling so as to pass through a 50 μm sieve. The ∼12 kg powder obtained in this way was homogenized both in a turbula mixer and manually. For the thus prepared loess material, good homogeneity for its K, Th and U content was found, as investigated via k 0 -INAA. For the final concentration and radiation dose-rate characterization, use was made of (next to NaI(Tl) field gamma-ray spectrometry and k 0 -INAA): extended energy-range low-background Ge gamma-ray spectrometry (also showing that the 232 Th and 238 U decay series were in secular equilibrium), thick source ZnS alpha-counting and GM beta-counting. For the latter', the conversion factors 'beta count-rate mutually implies radiation dose-rate' were

  4. Indoor radon levels and inhalation doses in dwellings near the some sites of Himachal Pradesh, India

    International Nuclear Information System (INIS)

    Bajwa, B.S.; Singh, S.; Virk, H.S.

    2005-01-01

    In view of the fact that radon and its daughters are a major source of natural radiation exposure, the measurement of radon concentration levels in dwellings has assumed ever-increasing importance. Keeping this in view, the indoor radon level measurements were carried out in the dwellings of different villages known to be located in the vicinity of uranium-mineralized pockets of Hamirpur district, Himachal Pradesh. Track-etch technique, a passive method using the Solid State Nuclear Track Detectors (SSNTDs), LR-115 type II, was utilized for these measurements. An attempt has been made to assess the levels of the indoor radon in the dwellings and inhalation dose rates of the population living in these villages. The radon concentrations were found to be varying with seasonal changes, building materials and mode of construction of houses. The radon concentrations were found to be higher in houses made from local sandstone and with mud floor in comparison to the houses having cemented brick floors. The annual indoor radon concentration and thus annual effective dose in most of the dwellings of these villages is certainly quite higher and even in some of the dwellings it even exceeds the upper limit of the proposed action level of ICRP, 1993. The inhalation dose rates in dwellings of these villages located in the vicinity of uranium mineralized pockets of Hamirpur district, Himachal Pradesh have been found to be quite higher than dose rate in the dwellings in the Amritsar city, Punjab, which is located in a completely uranium free zone. The radon survey in the dwellings of these villages has also been carried out using the Alpha-Guard technique, which is based on the pulse ionization chamber. The indoor radon concentration levels measured using the active technique of Alpha Guard have been found to be quite different from those measured in these dwellings by the passive technique of SSNTDs; indicating the importance of the SSNTDs in the long-term integrated measurement

  5. Evaluation of Activity Concentration Values and Doses due to the Transport of Low Level Radioactive Material

    Energy Technology Data Exchange (ETDEWEB)

    Rawl, Richard R [ORNL; Scofield, Patricia A [ORNL; Leggett, Richard Wayne [ORNL; Eckerman, Keith F [ORNL

    2010-04-01

    The International Atomic Energy Agency (IAEA) initiated an international Coordinated Research Project (CRP) to evaluate the safety of transport of naturally occurring radioactive material (NORM). This report presents the United States contribution to that IAEA research program. The focus of this report is on the analysis of the potential doses resulting from the transport of low level radioactive material. Specific areas of research included: (1) an examination of the technical approach used in the derivation of exempt activity concentration values and a comparison of the doses associated with the transport of materials included or not included in the provisions of Paragraph 107(e) of the IAEA Safety Standards, Regulations for the Safe Transport of Radioactive Material, Safety Requirements No. TS-R-1; (2) determination of the doses resulting from different treatment of progeny for exempt values versus the A{sub 1}/A{sub 2} values; and (3) evaluation of the dose justifications for the provisions applicable to exempt materials and low specific activity materials (LSA-I). It was found that the 'previous or intended use' (PIU) provision in Paragraph 107(e) is not risk informed since doses to the most highly exposed persons (e.g., truck drivers) are comparable regardless of intended use of the transported material. The PIU clause can also have important economic implications for co-mined ores and products that are not intended for the fuel cycle but that have uranium extracted as part of their industrial processing. In examination of the footnotes in Table 2 of TS-R-1, which identifies the progeny included in the exempt or A1/A2 values, there is no explanation of how the progeny were selected. It is recommended that the progeny for both the exemption and A{sub 1}/A{sub 2} values should be similar regardless of application, and that the same physical information should be used in deriving the limits. Based on the evaluation of doses due to the transport of low-level

  6. Verification of absorbed dose rates in reference beta radiation fields: measurements with an extrapolation chamber and radiochromic film

    Energy Technology Data Exchange (ETDEWEB)

    Reynaldo, S. R. [Development Centre of Nuclear Technology, Posgraduate Course in Science and Technology of Radiations, Minerals and Materials / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil); Benavente C, J. A.; Da Silva, T. A., E-mail: sirr@cdtn.br [Development Centre of Nuclear Technology / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2015-10-15

    Beta Secondary Standard 2 (Bss 2) provides beta radiation fields with certified values of absorbed dose to tissue and the derived operational radiation protection quantities. As part of the quality assurance, metrology laboratories are required to verify the reliability of the Bss-2 system by performing additional verification measurements. In the CDTN Calibration Laboratory, the absorbed dose rates and their angular variation in the {sup 90}Sr/{sup 90}Y and {sup 85}Kr beta radiation fields were studied. Measurements were done with a 23392 model PTW extrapolation chamber and with Gafchromic radiochromic films on a PMMA slab phantom. In comparison to the certificate values provided by the Bss-2, absorbed dose rates measured with the extrapolation chamber differed from -1.4 to 2.9% for the {sup 90}Sr/{sup 90}Y and -0.3% for the {sup 85}Kr fields; their angular variation showed differences lower than 2% for incidence angles up to 40-degrees and it reached 11% for higher angles, when compared to ISO values. Measurements with the radiochromic film showed an asymmetry of the radiation field that is caused by a misalignment. Differences between the angular variations of absorbed dose rates determined by both dosimetry systems suggested that some correction factors for the extrapolation chamber that were not considered should be determined. (Author)

  7. Verification of absorbed dose rates in reference beta radiation fields: measurements with an extrapolation chamber and radiochromic film

    International Nuclear Information System (INIS)

    Reynaldo, S. R.; Benavente C, J. A.; Da Silva, T. A.

    2015-10-01

    Beta Secondary Standard 2 (Bss 2) provides beta radiation fields with certified values of absorbed dose to tissue and the derived operational radiation protection quantities. As part of the quality assurance, metrology laboratories are required to verify the reliability of the Bss-2 system by performing additional verification measurements. In the CDTN Calibration Laboratory, the absorbed dose rates and their angular variation in the 90 Sr/ 90 Y and 85 Kr beta radiation fields were studied. Measurements were done with a 23392 model PTW extrapolation chamber and with Gafchromic radiochromic films on a PMMA slab phantom. In comparison to the certificate values provided by the Bss-2, absorbed dose rates measured with the extrapolation chamber differed from -1.4 to 2.9% for the 90 Sr/ 90 Y and -0.3% for the 85 Kr fields; their angular variation showed differences lower than 2% for incidence angles up to 40-degrees and it reached 11% for higher angles, when compared to ISO values. Measurements with the radiochromic film showed an asymmetry of the radiation field that is caused by a misalignment. Differences between the angular variations of absorbed dose rates determined by both dosimetry systems suggested that some correction factors for the extrapolation chamber that were not considered should be determined. (Author)

  8. Residual radioactive contamination from decommissioning: Technical basis for translating contamination levels to annual dose

    International Nuclear Information System (INIS)

    Kennedy, W.E. Jr.; Peloquin, R.A.

    1990-01-01

    This document describes the generic modeling of the total effective dose equivalent (TEDE) to an individual in a population from a unit concentration of residual radioactive contamination. Radioactive contamination inside buildings and soil contamination are considered. Unit concentration TEDE factors by radionuclide, exposure pathway, and exposure scenario are calculated. Reference radiation exposure scenarios are used to derive unit concentration TEDE factors for about 200 individual radionuclides and parent-daughter mixtures. For buildings, these unit concentration factors list the annual TEDE for volume and surface contamination situations. For soil, annual TEDE factors are presented for unit concentrations of radionuclides in soil during residential use of contaminated land and the TEDE per unit total inventory for potential use of drinking water from a ground-water source. Because of the generic treatment of potentially complex ground-water systems, the annual TEDE factors for drinking water for a given inventory may only indicate when additional site data or modeling sophistication are warranted. Descriptions are provided of the models, exposure pathways, exposure scenarios, parameter values, and assumptions used. An analysis of the potential annual TEDE resulting from reference mixtures of residual radionuclides is provided to demonstrate application of the TEDE factors. 62 refs., 5 figs., 66 tabs

  9. Radon-thoron levels and inhalation dose distribution patterns in India dwellings

    International Nuclear Information System (INIS)

    Ramachandran, T.V.; Eappen, K.P.; Nair, R.N.; Mayya, Y.S.; Sadasivan, S.

    2003-09-01

    A countrywide survey on radon and thoron levels has been carried out in Indian dwellings under a Coordinated Research Project sponsored by the Board of Research in Nuclear Sciences (BRNS), Department of Atomic Energy (DAE). Eight universities and a few research institutions from different parts of the country participated in this project. Under this project, radon and thoron levels were measured using Solid State Nuclear Track Detector (SSNTD) -spark counter based passive technique. A plastic twin chamber radon -thoron dosimeter was developed and standardized for the survey. This radon-thoron discriminating dosimeter uses three SSNTDs; two of which are exposed in cup modes and the third one is exposed in bare mode. Calibration factors (CF) are obtained for cup and bare mode SSNTDs through controlled experiments in a calibration facility. Calibration factors obtained from experiments showed very good agreement with the calibration factors derived from theoretical models. Four nodal centres were set up each at Kalpakkam, Jodhpur, Jaduguda and Mumbai for calibration and standardization of the dosimeter system. Inter calibration of the dosimeters were also carried out for comparison purpose. Nearly 4500 measurements in about 1400 dwellings were made during the survey period. An analysis of the data shows that the indoor radon gas concentrations at different locations vary between 4.6 and 147.0 Bq.m -3 with a geometric mean of 23.0 Bq.m -3 (GSD 2.61). Indoor thoron gas concentrations, in general, are found to be less than the radon concentrations and vary from 3.6 to 42.8 Bq.m -3 with a geometric mean of 12.2 Bq.m -3 (GSD 3.22). The mean annual inhalation dose rate due to radon, thoron and their progeny in the dwellings is estimated to be 0.97 mSv.y -1 (GSD 2.49). It is observed that the major contribution to the indoor inhalation dose is due to radon and its progeny. However, the contribution due to thoron and its progeny is not trivial as it is about 20 % of the total

  10. Evaluation and management of patients referred to a tertiary-level ...

    African Journals Online (AJOL)

    has been associated with two-thirds of strokes and almost half of ischaemic heart ... individuals with hypertension were on treatment, and of these only ... There are few published data on the control of hypertension and ... We therefore conducted a prospective study of patients referred ..... A recent meta-analysis by Briasoulis.

  11. Pilot-benchmarking of the WENRA safety reference levels for the spent fuel intermediate storage facility Ahaus

    International Nuclear Information System (INIS)

    Lorenz, Bernd; Roeder, Markus; Brandt, Klaus-Dieter

    2008-01-01

    Full text: The Western European Nuclear Regulator's Association (WENRA) has 2007 issued the draft of the 'Waste and Spent Fuel Storage Safety Reference Levels'. The objective of WENRA is to strive for a harmonized safety level of nuclear facilities within the European Community and these Reference Levels are a benchmark method to demonstrate the achieved level for the regulatory system and the implementation as well. Safety Reference Levels exist at the moment for Reactor Safety, Waste Storage and Decommissioning in different stages of development. ENISS, the European Nuclear Installations Safety Standards Initiative, a FORATOM based special organisation of nuclear operators, has discussed these Safety Reference Levels very intensively with WENRA and the agreement was to make a implementation benchmark-exercise for the storage facilities before the authorities finally agree on the Reference Levels. This benchmark was scheduled for the year 2008. Because of the special situation in Germany where a large number of storage facilities is in operation the German authorities felt that it would be useful to initiate a Pilot-Benchmark to get first results on the feasibility of the Reference Levels and the burden imposed to authorities and operators by these benchmark-exercises. GNS, a subsidiary company of the utilities, agreed to step into this process on a voluntary basis with its storage facility for spent fuel in Ahaus. The exercise was done in a very efficient way and in good co-operation between the authorities, local and federal, and the operator. The results in terms of safety assessments have been very satisfactory showing the high degree of safety. Although the facility was for the first time licensed already in 1987 the compliance with nearly all Reference Levels from 2007 could be demonstrated. It became also clear that newer facilities would fulfil the desired safety standard too. Nevertheless, in spite of the good results the exercise revealed some weak

  12. Dose estimation for nuclear power plant 4 accident in Taiwan at Fukushima nuclear meltdown emission level.

    Science.gov (United States)

    Tang, Mei-Ling; Tsuang, Ben-Jei; Kuo, Pei-Hsuan

    2016-05-01

    An advanced Gaussian trajectory dispersion model is used to evaluate the evacuation zone due to a nuclear meltdown at the Nuclear Power Plant 4 (NPP4) in Taiwan, with the same emission level as that occurred at Fukushima nuclear meltdown (FNM) in 2011. Our study demonstrates that a FNM emission level would pollute 9% of the island's land area with annual effective dose ≥50 mSv using the meteorological data on 11 March 2011 in Taiwan. This high dose area is also called permanent evacuation zone (denoted as PEZ). The PEZ as well as the emergency-planning zone (EPZ) are found to be sensitive to meteorological conditions on the event. In a sunny day under the dominated NE wind conditions, the EPZ can be as far as 100 km with the first 7-day dose ≥20 mSv. Three hundred sixty-five daily events using the meteorological data from 11 March 2011 to 9 March 2012 are evaluated. It is found that the mean land area of Taiwan in becoming the PEZ is 11%. Especially, the probabilities of the northern counties/cities (Keelung, New Taipei, Taipei, Taoyuan, Hsinchu City, Hsinchu County and Ilan County) to be PEZs are high, ranging from 15% in Ilan County to 51% in Keelung City. Note that the total population of the above cities/counties is as high as 10 million people. Moreover, the western valleys of the Central Mountain Range are also found to be probable being PEZs, where all of the reservoirs in western Taiwan are located. For example, the probability can be as high as 3% in the far southern-most tip of Taiwan Island in Pingtung County. This shows that the entire populations in western Taiwan can be at risk due to the shortage of clean water sources under an event at FNM emission level, especially during the NE monsoon period. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Effects of Different Containers on Radioactivity Measurements using a Dose Calibrator with Special Reference to 111In and 123I.

    Science.gov (United States)

    Inoue, Yusuke; Abe, Yutaka; Kikuchi, Kei; Miyatake, Hiroki; Watanabe, Atsushi

    2017-01-01

    Low-energy characteristic x-rays emitted by 111 In and 123 I sources are easily absorbed by the containers of the sources, affecting radioactivity measurements using a dose calibrator. We examined the effects of different containers on the estimated activities. The radioactivities of 111 In, 123 I, 201 Tl, and 99m Tc were measured in containers frequently employed in clinical practice in Japan. The 111 In measurements were performed in the vials A and B of the 111 In-pentetreotide preparation kit and in the plastic syringe. The activities of 123 I-metaiodobenzylguanidine and 201 Tl chloride were measured in the prefilled glass syringes and plastic syringes. The milking vial, vial A, vial B, and plastic syringe were used to assay 99m Tc. For 111 In and 123 I, measurements were performed with and without a copper filter. The filter was inserted into the well of the dose calibrator to absorb low-energy x-rays. The relative estimate was defined as the ratio of the activity estimated with the dose calibrator to the standard activity. The estimated activities varied greatly depending on the container when 111 In and 123 I sources were assayed without the copper filter. The relative estimates of 111 In were 0.908, 1.072, and 1.373 in the vial A, vial B, and plastic syringe, respectively. The relative estimates of 123 I were 1.052 and 1.352 in the glass syringe and plastic syringe, respectively. Use of the copper filter eliminated the container-dependence in 111 In and 123 I measurements. Container-dependence was demonstrated in neither 201 Tl nor 99m Tc measurements. The activities of 111 In and 123 I estimated with a dose calibrator differ greatly among the containers. Accurate estimation may be attained using the container-specific correction factor or using the copper filter.

  14. Reference values in indicators of patient dose; Valores de referencia en los indicadores de dosis a paciente

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Llorente, P. L.; Hernandez Rodriguez, J.; Ramos Pacho, J. A.; Verde Velasco, J. M.; Fernandez Bordes, M.; Martin Rincon, C.; Montes fuentes, C.; Garcia Repiso, S.; Sena Espinel, E. de; Martin Nunoz, J.

    2011-07-01

    The RD 1976/1999 on Quality Assurance in Diagnostic Radiology laid the foundation for developing the Radiological Protection of Patient compliance with the relevant Directive EURATOM. More than ten years of implementation, we consider an urgent review and update its content due to the legal implications involved as set forth therein, especially in the aspects that have to do with the measurement of patient dose indicators, and more specifically in exploration called complex and CAT.

  15. Radon level and radon effective dose rate determination in Moroccan dwellings using SSNTDs

    International Nuclear Information System (INIS)

    Oufni, L.; Misdaq, M.A.; Amrane, M.

    2005-01-01

    Inhalation of radon ( 222 Rn) and its daughter product are a major source of natural radiation exposure. The measurement of radon activity in dwelling is assuming ever increasing importance. It is known from recent surveys in many countries that radon and its progeny contribute significantly to total inhalation dose and it is fairly established that radon when inhaled in large quantity causes lung disorder. Keeping this in view, the indoor radon activity level and radon effective dose rate were carried out in the dwellings of Beni-Mellal, Khouribgra and Ben Guerir cities, Morocco, using the solid state nuclear track detectors (SSNTD) technique. Assuming an indoor occupancy factor of 0.8 and 0.4 for the equilibrium factor of radon indoors, we found that the 222 Rn effective dose rate in the studied dwellings ranges from 1.01 to 7.90mSvy -1 . The radon activity in the corresponding dwellings was found to vary from 40 to 532Bqm -3 . The radon activity has not only been found to vary with seasonal changes, but also with the age, the construction mode of houses, the ventilation conditions and with specific sites and geological materials

  16. The scientific basis for the establishment of threshold levels and dose response relationships of carcinogenesis

    International Nuclear Information System (INIS)

    1975-01-01

    The International Atomic Energy Agency hosted a two day Symposium from 2-3 December 1974 at its Headquarters, organized by the 'International Academy for Environmental Safety and the Forum fur Wissenschaft, Wirtschaft und Politik' on the subject 'Scientific Basis for the Establishment of Threshold. Levels and Dose Response Relationships of Carcinogenesis'. Following an introductory paper by the Radiation Biology Section of the Agency on 'Radiation Carcinogenesis - Dose Response Relationship, Threshold and Risk Estimates', a series of papers dealt with this problem in chemical carcinogenesis.It was suggested that more experiments should be done using non-human primates for tests of carcinogens, especially chemicals. Preliminary experiments using monkeys with a potent carcinogen - nitrosoamine - indicate that there could possibly be a dose where no effect can be observed during the 5 year period of study. It was also pointed out that the overall cost/benefit and risk/ benefit relationships should be taken into consideration in determining limits for chemicals which are potentially carcinogenic but are used routinely by the public and industries; these considerations have been weighed in setting exposure limits for radiation

  17. Effect of low dose radiation on POMC transcription level in mouse hypothalamus and immune organs

    International Nuclear Information System (INIS)

    Wan Hong; Liu Shuzheng

    1998-01-01

    Objective: To disclose the changes in mRNA transcription level of POMC in the hypothalamus and immune organs after low dose radiation. Method: In situ hybridization was used to examine the changes of POMC mRNA transcription level in mouse hypothalamus and immune organs following whole body irradiation (WBI) with 75 mGy X-rays. Results: There was a basal expression of POMC mRNA in both the hypothalamus and immune organs. POMC mRNA-positive neutron were located in the arcuate nucleus of hypothalamus. WBI with 75 mGy X-rays could significantly down-regulate the POMC transcription level that was remarkable within 1h and remained low in the observation period of 12h. POMC transcription level in mouse immune organs increased with time within 8h after irradiation and then began to decrease but still remained at a higher than normal level. The changes of POMC transcription level were more marked in the spleen than in other immune organs. Conclusion: These findings suggest that the immediate decrease of POMC transcription level in the hypothalamus might be the direct cause of the down-regulation of the hypothalamus-pituitary-adrenocortical axis after WBI with 75 mGy X-rays, accompanied with an increase in POMC transcription in immune organs

  18. Some problems in the action level and dose assesment of radon

    International Nuclear Information System (INIS)

    Pan Ziqiang

    2007-01-01

    In the recent past, remarkable progresses has been made in radon epidemiological investigation for human populations, with the radon-induced excess relative risk being 0.16%/100 Bq m -3 . It should be noted, for implementing radon action standards, that the action levels are differently implicated for population dwellings and workplaces. The dose limits and the derived air concentration are provided for the individuals, both of which can not be used as the main basis for con- trolling workplaces (sources). The controlling of radon concentrations should be based primarily on radiation protection optimization and constraints. (authors)

  19. Ambient radioactivity levels and radiation doses. Annual report 2014; Umweltradioaktivitaet und Strahlenbelastung. Jahresbericht 2014

    Energy Technology Data Exchange (ETDEWEB)

    Trugenberger-Schnabel, Angela; Loebke-Reinl, Angelika; Peter, Josef (comps.) [Bundesamt fuer Strahlenschutz, Salzgitter (Germany)

    2016-08-15

    The annual report 2014 on ambient radioactivity levels and radiation doses covers the following topics: (1) Actual data and their evaluation: natural environmental radioactivity, artificial environmental radioactivity, occupational radiation exposure, radiation exposures from medical applications, handling of radioactive materials and sources of ionizing radiation, non-ionizing radiation. (2) Fundamentals and general information: legal basis and explanations, basic information on natural environmental radioactivity, basic information on artificial radioactivity in the environment, basic information on occupational radiation exposure, basic information on radiation exposures from medical applications, basic information on the handling of radioactive materials and sources of ionizing radiation, basic information on non-ionizing radiation. (3) Tables.

  20. Cumulative effective and individual organ dose levels in paediatric patients undergoing multiple catheterizations for congenital heart disease

    International Nuclear Information System (INIS)

    Jones, T.P.; Brennan, P.C.; Ryan, E.

    2017-01-01

    This study examines the cumulative radiation dose levels received by a group of children who underwent multiple cardiac catheterisation procedures during the investigation and management of congenital heart disease (CHD). The purpose is to calculate cumulative doses, identify higher dose individuals, outline the inconsistencies with risk assessment and encourage the establishment of dose databases in order to facilitate the longitudinal research necessary to better understand health risks. A retrospective review of patient records for 117 paediatric patients who have undergone two or more cardiac catheterizations for the investigation of CHD was undertaken. This cohort consisted of patients who were catheterised over a period from September 2002 to August 2014. The age distribution was from newborn to 17 y. Archived kerma-area product (P KA ) and fluoroscopy time (T) readings were retrieved and analysed. Cumulative effective and individual organ doses were determined. The cumulative P KA levels ranged from 1.8 to 651.2 Gycm 2 , whilst cumulative effective dose levels varied from 2 to 259 mSv. The cumulative fluoroscopy time was shown to vary from 8.1 to 193.5 min. Median cumulative organ doses ranged from 3 to 94 mGy. Cumulative effective dose levels are highly variable but may exceed 250 mSv. Individual organ and effective dose measurements remain useful for comparison purposes between institutions although current methodologies used for determining lifetime risks are inadequate. (authors)

  1. Radiolysis of n-dodecane and its physical property change based on the dose in one pass through a reference high active (HA) column

    International Nuclear Information System (INIS)

    Ikeda, Hidematsu; Suzuki, Atsuyuki

    1998-01-01

    The radiolysis of n-dodecane which is used both as diluent and as scrub solution and its physical property change were studied by irradiation from a 60 Co γ-source under the relative condition of the HA column in Purex process. First, the radiation exposure of organic phase in one pass through the HA columns were calculated by using the reference HA columns. Then, the radiolysis of the commercial n-dodecane without purification was investigated under the several dose conditions based on the absorption in one pass through the reference HA columns. A large variety of additional n-alkane degradation products was observed and they were increased with dose. The G-value in lower exposure was a high yield, and the absolute G-value decreased with increasing radiation exposure to 1.01 W·h/l. Several expected inferable species from previous literature and three schemes for both principal radiolysis products and reaction of n-dodecane were suggested. These chemical products were probably formed in open system with gamma rays. The physical property change was also performed, and the effect of decomposition products on its change was small but not ignored. The annular with nozzle plates column diminished the absorbed dose in comparison with the other combination columns. (author)

  2. The ampakine, Org 26576, bolsters early spatial reference learning and retrieval in the Morris water maze: a subchronic, dose-ranging study in rats.

    Science.gov (United States)

    Hamlyn, Eugene; Brand, Linda; Shahid, Mohammed; Harvey, Brian H

    2009-10-01

    Ampakines have shown beneficial effects on cognition in selected animal models of learning. However, their ability to modify long-term spatial memory tasks has not been studied yet. This would lend credence to their possible value in treating disorders of cognition. We evaluated the actions of subchronic Org 26576 administration on spatial reference memory performance in the 5-day Morris water maze task in male Sprague-Dawley rats, at doses of 1, 3 and 10 mg/kg twice daily through intraperitoneal injection over 12 days. Org 26576 exerted a dose and time-dependent effect on spatial learning, with dosages of 3 and 10 mg/kg significantly enhancing acquisition on day 1. Globally, escape latency decreased significantly as the training days progressed in the saline and Org 26576-treated groups, indicating that significant and equal learning had taken place over the learning period. However, at the end of the learning period, all doses of Org 26576 significantly improved spatial memory storage/retrieval without confounding effects in the cued version of the task. Org 26576 offers early phase spatial memory benefits in rats, but particularly enhances search accuracy during reference memory retrieval. These results support its possible utility in treating disorders characterized by deficits in cognitive performance.

  3. Low and intermediate level waste in SFR-1. Reference Waste Inventory 2007

    Energy Technology Data Exchange (ETDEWEB)

    Almkvist, Lisa (Vattenfall Power Consultant AB, Stockholm (SE)); Gordon, Anna (Swedish Nuclear Fuel and Waste Management Co., Stockholm (SE))

    2007-11-15

    The objective with this report is to describe all the waste and the waste package that is expected to be deposited in SFR 1 at the time of closure. The report will form the basis for the release calculation in the safety analysis for SFR 1. Three different scenarios are explored in this report; the waste inventory is based on an estimated operational lifetime of the Swedish nuclear power plants of 50 and 60 years and that closure of the SFR 1 repository will take place in 2040 or 2050 respectively. The third scenario is where the repository is full (one part where the activity adds up to 1016 Bq and one part where the repository is considered full regarding volume). In the report, data about geometries, weights, materials, chemicals and radionuclide are given. No chemotoxic material has been identified in the waste. The inventory is estimated using the Prosit-interface which extracts information from the Triumf database. The inventory is based on so called 'waste types' and the waste types' 'reference waste package'. The reference waste package combined with a prognosis of the number of waste packages to be delivered to SFR 1 gives the final waste inventory for SFR 1. All reference waste packages are thoroughly described in the appendices of this report. The reference waste packages are as far as possible based on actual experiences and measurements. The radionuclide inventory is also based on actual measurements. The inventory is based on measurements of 60Co and 137Cs in waste packages and on measurements of 239Pu and 240Pu in reactor water. Other nuclides in the inventory are calculated with correlation factors

  4. Low and intermediate level waste in SFR-1. Reference waste inventory

    International Nuclear Information System (INIS)

    Riggare, P.; Johansson, Claes

    2001-06-01

    The objective with this report is to describe all the waste and the waste package that is expected to be deposited in SFR-1 at the time of closure. This report is a part of the SAFE project (Safety Assessment of Final Repository for Radioactive Operational Waste), i.e. the renewed safety assessment of SFR-1. The accounted waste inventory has been used as input to the release calculation that has been performed in the SAFE project. The waste inventory is based on an estimated operational lifetime of the Swedish nuclear power plants of 40 years and that closure of the SFR repository will happen in 2030. In the report, data about geometries, weights, materials, chemicals and radionuclide are given. No chemo toxic material has been identified in the waste. The inventory is based on so called waste types and the waste types reference waste package. The reference waste package combined with a prognosis of the number of waste packages to the year 2030 gives the final waste inventory for SFR-1. All reference waste packages are thoroughly described in the appendices of this report. The reference waste packages are as far as possible based on actual experiences and measurements. The radionuclide inventory is also based on actual measurements. The inventory is based on measurements of 60 Co and 137 Cs in waste packages and on measurements 239 Pu and 240 Pu in reactor water. Other nuclides in the inventory are calculated with correlation factors. In the SAFE project's prerequisites it was said that one realistic and one conservative (pessimistic) inventory should be produced. The conservative one should then be used for the release calculations. In this report one realistic and one conservative radionuclide inventory is presented. The conservative one adds up to 10 16 Bq. Regarding materials there is only one inventory given since it is not certain what is a conservative assumption

  5. Low and intermediate level waste in SFR-1. Reference Waste Inventory 2007

    International Nuclear Information System (INIS)

    Almkvist, Lisa; Gordon, Ann

    2007-11-01

    The objective with this report is to describe all the waste and the waste package that is expected to be deposited in SFR 1 at the time of closure. The report will form the basis for the release calculation in the safety analysis for SFR 1. Three different scenarios are explored in this report; the waste inventory is based on an estimated operational lifetime of the Swedish nuclear power plants of 50 and 60 years and that closure of the SFR 1 repository will take place in 2040 or 2050 respectively. The third scenario is where the repository is full (one part where the activity adds up to 1016 Bq and one part where the repository is considered full regarding volume). In the report, data about geometries, weights, materials, chemicals and radionuclide are given. No chemotoxic material has been identified in the waste. The inventory is estimated using the Prosit-interface which extracts information from the Triumf database. The inventory is based on so called 'waste types' and the waste types' 'reference waste package'. The reference waste package combined with a prognosis of the number of waste packages to be delivered to SFR 1 gives the final waste inventory for SFR 1. All reference waste packages are thoroughly described in the appendices of this report. The reference waste packages are as far as possible based on actual experiences and measurements. The radionuclide inventory is also based on actual measurements. The inventory is based on measurements of 60 Co and 137 Cs in waste packages and on measurements of 239 Pu and 240 Pu in reactor water. Other nuclides in the inventory are calculated with correlation factors

  6. Tails from previous exposures: a general problem in setting reference levels for the assessment of internal contamination

    International Nuclear Information System (INIS)

    Breuer, F.; Frittelli, L.

    1988-01-01

    Reference levels for retention and excretion are evaluated for routine and special monitoring following the intake of a fraction of ICRP annual limits (ALIs) or of a unit activity. Methodologies are also suggested for taking into account the contribution by previous intakes to excretion or retention

  7. Commentary Variations: Level of Verbalization, Personal Reference, and Phase Relations in Instructional Films on Perceptual-Motor Tasks. Technical Report.

    Science.gov (United States)

    Zuckerman, John V.

    In an experiment to determine the most efficient design for the commentary of an instructional film, special consideration was given to three variables concerned with the construction of commentaries: the level of verbalization (the amount of talk), the personal reference of the narrator, and the phase relationship between the commentary and the…

  8. Annual limits on intake for members of the public and derived reference levels of radionuclide concentrations in the environment

    International Nuclear Information System (INIS)

    Mason, G.C.

    1983-01-01

    A proposal is presented recommending the introduction in Australia of Annual Limits on Intake of radionuclides for members of the public and of corresponding reference levels of radionuclide concentrations in the environment. The proposal is related to recent recommendations of the International Commission on Radiological Protection and draft recommendations under consideration by the International Atomic Energy Agency

  9. Children and adults exposed to electromagnetic fields at the ICNIRP reference levels: Theoretical assessment of the induced peak temperature increase

    NARCIS (Netherlands)

    J. Bakker (Jan); M.M. Paulides (Maarten); E. Neufeld; A. Christ (A.); N. Kuster (Niels); G.C. van Rhoon (Gerard)

    2011-01-01

    textabstractTo avoid potentially adverse health effects of electromagnetic fields (EMF), the International Commission on Non-Ionizing Radiation Protection (ICNIRP) has defined EMF reference levels. Restrictions on induced whole-body-averaged specific absorption rate (SAR wb) are provided to keep the

  10. Accuracy of Acuros XB and AAA dose calculation for small fields with reference to RapidArc stereotactic treatments

    International Nuclear Information System (INIS)

    Fogliata, Antonella; Nicolini, Giorgia; Clivio, Alessandro; Vanetti, Eugenio; Cozzi, Luca

    2011-01-01

    Purpose: To assess the accuracy against measurements of two photon dose calculation algorithms (Acuros XB and the Anisotropic Analytical algorithm AAA) for small fields usable in stereotactic treatments with particular focus on RapidArc. Methods: Acuros XB and AAA were configured for stereotactic use. Baseline accuracy was assessed on small jaw-collimated open fields for different values for the spot sizes parameter in the beam data: 0.0, 0.5, 1, and 2 mm. Data were calculated with a grid of 1 x 1 mm 2 . Investigated fields were: 3 x 3, 2 x 2, 1 x 1, and 0.8 x 0.8 cm 2 with a 6 MV photon beam generated from a Clinac2100iX (Varian, Palo Alto, CA). Profiles, PDD, and output factors were measured in water with a PTW diamond detector (detector size: 4 mm 2 , thickness 0.4 mm) and compared to calculations. Four RapidArc test plans were optimized, calculated and delivered with jaw settings J3 x 3, J2 x 2, and J1 x 1 cm 2 , the last was optimized twice to generate high (H) and low (L) modulation patterns. Each plan consisted of one partial arc (gantry 110 deg. to 250 deg.), and collimator 45 deg. Dose to isocenter was measured in a PTW Octavius phantom and compared to calculations. 2D measurements were performed by means of portal dosimetry with the GLAaS method developed at authors' institute. Analysis was performed with gamma pass-fail test with 3% dose difference and 2 mm distance to agreement thresholds. Results: Open square fields: penumbrae from open field profiles were in good agreement with diamond measurements for 1 mm spot size setting for Acuros XB, and between 0.5 and 1 mm for AAA. Maximum MU difference between calculations and measurements was 1.7% for Acuros XB (0.2% for fields greater than 1 x 1 cm 2 ) with 0.5 or 1 mm spot size. Agreement for AAA was within 0.7% (2.8%) for 0.5 (1 mm) spot size. RapidArc plans: doses were evaluated in a 4 mm diameter structure at isocenter and computed values differed from measurements by 0.0, -0.2, 5.5, and -3.4% for

  11. Accuracy of Acuros XB and AAA dose calculation for small fields with reference to RapidArc stereotactic treatments

    Energy Technology Data Exchange (ETDEWEB)

    Fogliata, Antonella; Nicolini, Giorgia; Clivio, Alessandro; Vanetti, Eugenio; Cozzi, Luca [Oncology Institute of Southern Switzerland, Medical Physics Unit, CH-6500 Bellinzona (Switzerland)

    2011-11-15

    Purpose: To assess the accuracy against measurements of two photon dose calculation algorithms (Acuros XB and the Anisotropic Analytical algorithm AAA) for small fields usable in stereotactic treatments with particular focus on RapidArc. Methods: Acuros XB and AAA were configured for stereotactic use. Baseline accuracy was assessed on small jaw-collimated open fields for different values for the spot sizes parameter in the beam data: 0.0, 0.5, 1, and 2 mm. Data were calculated with a grid of 1 x 1 mm{sup 2}. Investigated fields were: 3 x 3, 2 x 2, 1 x 1, and 0.8 x 0.8 cm{sup 2} with a 6 MV photon beam generated from a Clinac2100iX (Varian, Palo Alto, CA). Profiles, PDD, and output factors were measured in water with a PTW diamond detector (detector size: 4 mm{sup 2}, thickness 0.4 mm) and compared to calculations. Four RapidArc test plans were optimized, calculated and delivered with jaw settings J3 x 3, J2 x 2, and J1 x 1 cm{sup 2}, the last was optimized twice to generate high (H) and low (L) modulation patterns. Each plan consisted of one partial arc (gantry 110 deg. to 250 deg.), and collimator 45 deg. Dose to isocenter was measured in a PTW Octavius phantom and compared to calculations. 2D measurements were performed by means of portal dosimetry with the GLAaS method developed at authors' institute. Analysis was performed with gamma pass-fail test with 3% dose difference and 2 mm distance to agreement thresholds. Results: Open square fields: penumbrae from open field profiles were in good agreement with diamond measurements for 1 mm spot size setting for Acuros XB, and between 0.5 and 1 mm for AAA. Maximum MU difference between calculations and measurements was 1.7% for Acuros XB (0.2% for fields greater than 1 x 1 cm{sup 2}) with 0.5 or 1 mm spot size. Agreement for AAA was within 0.7% (2.8%) for 0.5 (1 mm) spot size. RapidArc plans: doses were evaluated in a 4 mm diameter structure at isocenter and computed values differed from measurements by 0.0, -0

  12. Effect of low level doses of fast neutrons on the activity of the snake venom

    International Nuclear Information System (INIS)

    Hanafy, Magda S.; Amin, Aida M.

    1998-01-01

    In this work, the effect of low level doses of fast neutrons from 252 Cf on snake venom (Cerastes cerastes) was studied through measurements of biophysical and haematological changes. The absorption spectrum (200-700 nm) of haemoglobin (Hb) collected from the blood of rats after 3 and 24 hours post injection with irradiated and non-irradiated snake venom with neutron fluences of 3x10 6 , 2.8x10 7 and 3X10 8 n/cm 2 was measured. The results indicated that injection of animals with either non- irradiated or irradiated venom ( with different neutron fluences) resulted into the decrease of the absorption band intensities of Hb. These changes in the properties of the characteristic band showed to be a marker for irradiated venom and is dose dependent. It was concluded that neutron irradiation of the venom leads to the decrease of its toxicity and, consequently, to the increase of the chance of repair mechanism in livings. Obvious changes of most haematological erythrocytic values of Hb, packed cell volume (PCV), red blood counts (RBC), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCHb) and mean corpuscular haemoglobin concentration (MCHC) were observed in the blood of the rats injected with non-irradiated venom (as a first group) and those injected with the irradiated venom (as a second group). The microcytic haemolytic anemia was more acute in the first group than in the second one which showed lesser extent. It is concluded from this study that low level doses of fast neutrons could postpone and lower acute haematological action induced by the venom. (authors)

  13. Air Pathway Dose Modeling for the E-Area Low-Level Waste Facility

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, K. L. [Savannah River Site (SRS), Aiken, SC (United States); Minter, K. M. [Savannah River Site (SRS), Aiken, SC (United States)

    2017-09-06

    Dose-release factors (DRFs) were calculated for potential atmospheric releases of several radionuclides from the E-Area Low-Level Waste Facility (ELLWF). The ELLWF receives solid low-level radioactive waste from across the Savannah River Site (SRS) and offsite for disposal. These factors represent the maximum dose a receptor would receive if standing at either 100 m or 11,410 m (Site Boundary) from the edge of an ELLWF disposal unit which are points of assessment (POA) for Department of Energy (DOE) Order 435.1 performance assessments (PA). The DRFs were calculated for 1 Ci of the specified radionuclide being released from the ground surface to the atmosphere (mrem per curie released). The calculation conservatively represented the ELLWF as a point source, and conservatively assumed the receptor was positioned at the center of the contaminant plume and continuously exposed for a period of one year. These DRFs can be refined to take into consideration disposal unit size, proximity and timing of peak dose to establish less conservative radionuclide specific disposal limits. DRFs were calculated for H-3 and C-14 in Revision 0 of this report. H-3 as HTO and C-14 as CO2 were identified as volatile radionuclides of potential concern in earlier radionuclide screening studies. In Revision 1, DRFs were calculated for eight additional radionuclides identified by an updated screening analysis as potentially important volatile radionuclides. These include Ar-37, Ar-39, Ar-42, Hg-194, Hg- 203, Kr-81, Kr-85, and Xe-127.

  14. Critical reevaluation of the dose-response relationships for carcinogenic effects of low-level ionizing radiation

    International Nuclear Information System (INIS)

    Upton, A.C.

    2003-01-01

    In recent decades, it has been customary, for radiation protection purposes, to assume that the overall risk of radiation-induced cancer increases as a linear-nonthreshold function of the dose. The existing data do not exclude the existence of a threshold, however, and the dose-response relationship is known to vary, depending on the type of cancer in queation, the dose, dose rate, and LET of the radiation, the age, sex, and physiological state of the exposed individuals, and other variables, including the potential influence of adaptive responses and bystander effects at low doses. In light of advncing knowledge, therefore, the dose-response relationship for carcinogenic effects of low-level radiation has been reevaluated periodically by the National Council on Radiation Protection and Measurements, the International Commission of Radiological Protection, the United Nations Scientific Committee on the Effects of Atomic Radiation, the U.S. National Academy of Sciences, and other organizations. The most recent such reviews have generally found the weight of evidence to suggest that lesions which are precursors to cancer (i.e., mutations and chromosome aberrations), and certain types of cancer as well, may increase in frequency linearly with the dose in the low-dose domain. On this basis, it is concluded that no alternative dose-response model for the carcinogenic effects of low-level radiation is more plausible than the linear-nonthreshold model, although other dose-response relationships cannot be excluded. (authors)

  15. [Electroconvulsive therapy and level of evidence: From causality to dose-effect relationship].

    Science.gov (United States)

    Micoulaud-Franchi, J-A; Quilès, C; Cermolacce, M; Belzeaux, R; Adida, M; Fakra, E; Azorin, J-M

    2016-12-01

    The first objective of this article is to summarize the history of electroconvulsive therapy (ECT) in psychiatry in order to highlight the transition from clinical level of evidence based on phenomenological descriptions to controlled trial establishing causal relationship. The second objective is to apply the criteria of causation for ECT, to focus on the dose-effect relationship criteria, and thus to analyze the conditions of application of these criteria for ECT. A literature review exploring the use of electricity, ECT and electroencephalography (EEG) in psychiatry was conducted. The publications were identified from the Pubmed and GoogleScholar electronic databases. The scientific literature search of international articles was performed in July 2016. In 1784, a Royal commission established in France by King Louis XVI tested Mesmer's claims concerning animal magnetism. By doing that, the commission, including such prominent scientists as the chemist Anton Lavoisier and the scientist and researcher on electricity and therapeutics Benjamin Franklin, played a central role in establishing the criteria needed to assess the level of evidence of electrical therapeutics in psychiatry. Surprisingly, it is possible to identify the classical Bradford Hill criteria of causation in the report of the commission, except the dose-effect relationship criteria. Since then, it has been conducted blinded randomized controlled trials that confirmed the effectiveness of ECT against ECT placebos for the treatment of psychiatric disorders. At present, the dose-effect relationship criteria can be analyzed through an EEG quality assessment of ECT-induced seizures. EEG quality assessment includes several indices: TSLOW (time to onset of seizure activity ≤5Hz, seconds), peak mid-ictal amplitude (mm), regularity (intensity or morphology of the seizure (0-6)), stereotypy (global seizure patterning, 0-3) and post-ictal suppression (0-3). A manual rating sheet is needed to score theses

  16. Parallel implementation of multireference coupled-cluster theories based on the reference-level parallelism

    Energy Technology Data Exchange (ETDEWEB)

    Brabec, Jiri; Pittner, Jiri; van Dam, Hubertus JJ; Apra, Edoardo; Kowalski, Karol

    2012-02-01

    A novel algorithm for implementing general type of multireference coupled-cluster (MRCC) theory based on the Jeziorski-Monkhorst exponential Ansatz [B. Jeziorski, H.J. Monkhorst, Phys. Rev. A 24, 1668 (1981)] is introduced. The proposed algorithm utilizes processor groups to calculate the equations for the MRCC amplitudes. In the basic formulation each processor group constructs the equations related to a specific subset of references. By flexible choice of processor groups and subset of reference-specific sufficiency conditions designated to a given group one can assure optimum utilization of available computing resources. The performance of this algorithm is illustrated on the examples of the Brillouin-Wigner and Mukherjee MRCC methods with singles and doubles (BW-MRCCSD and Mk-MRCCSD). A significant improvement in scalability and in reduction of time to solution is reported with respect to recently reported parallel implementation of the BW-MRCCSD formalism [J.Brabec, H.J.J. van Dam, K. Kowalski, J. Pittner, Chem. Phys. Lett. 514, 347 (2011)].

  17. A system for protecting the environment from ionising radiation: selecting reference fauna and flora, and the possible dose models and environmental geometries that could be applied to them.

    Science.gov (United States)

    Pentreath, R J; Woodhead, D S

    2001-09-28

    In order to demonstrate, explicitly, that the environment can be protected with respect to controlled sources of ionising radiation, it is essential to have a systematic framework within which dosimetry models for fauna and flora can be used. And because of the practical limitations on what could reasonably be modelled and the amount of information that could reasonably be obtained, it is also necessary to limit the application of such models to a 'set' of fauna and flora within a reference' context. This paper, therefore, outlines the factors that will need to be considered to select such 'reference' fauna and flora, and describes some of the factors and constraints necessary to develop the associated dosimetry models. It also describes some of the most basic environmental geometrics within which the dose models could be set in order to make comparisons amongst different radiation sources.

  18. A system for protecting the environment from ionising radiation. Selecting reference fauna and flora, and the possible dose models and environmental geometries that could be applied to them

    International Nuclear Information System (INIS)

    Pentreath, R.J.; Woodhead, D.S.

    2001-01-01

    In order to demonstrate, explicitly, that the environment can be protected with respect to controlled sources of ionising radiation, it is essential to have a systematic framework within which dosimetry models for fauna and flora can be used. And because of the practical limitations on what could reasonably be modelled and the amount of information that could reasonably be obtained, it is also necessary to limit the application of such models to a 'set' of fauna and flora within a 'reference' context. This paper, therefore, outlines the factors that will need to be considered to select such 'reference' fauna and flora, and describes some of the factors and constraints necessary to develop the associated dosimetry models. It also describes some of the most basic environmental geometries within which the dose models could be set in order to make comparisons amongst different radiation sources

  19. Risks associated with low level ionizing radiation (with special reference to nuclear power workers)

    International Nuclear Information System (INIS)

    1989-01-01

    This document describes a project to use epidemiological studies of workers in the nuclear industry to estimate the cancer risk associated with low-dose chronic exposure to ionizing radiation. The project aims both to improve the basis for radiation risk assessment and to test the validity of currently used models for the extrapolation of radiation risk. This report focusses on the former aim, and summarizes discussions at two meetings held in June 1988. One of these was a small working group consisting mainly of epidemiologists who had carried out studies of nuclear workers; the other included nominees of the nuclear industries of eleven countries as well as epidemiologists and radiation physicists and biologists. As a result of the meetings, efforts are underway to pool existing data and a feasibility study is addressing the possibility of an international collaborative study of unstudied groups of nuclear workers

  20. Research on maximum level noise contaminated of remote reference magnetotelluric measurements using synthesized data

    Science.gov (United States)

    Gang, Zhang; Fansong, Meng; Jianzhong, Wang; Mingtao, Ding

    2018-02-01

    Determining magnetotelluric impedance precisely and accurately is fundamental to valid inversion and geological interpretation. This study aims to determine the minimum value of signal-to-noise ratio (SNR) which maintains the effectiveness of remote reference technique. Results of standard time series simulation, addition of different Gaussian noises to obtain the different SNR time series, and analysis of the intermediate data, such as polarization direction, correlation coefficient, and impedance tensor, show that when the SNR value is larger than 23.5743, the polarization direction disorder at morphology and a smooth and accurate sounding carve value can be obtained. At this condition, the correlation coefficient value of nearly complete segments between the base and remote station is larger than 0.9, and impedance tensor Zxy presents only one aggregation, which meet the natural magnetotelluric signal characteristic.

  1. Dose critical in-vivo detection of anti-cancer drug levels in blood

    Science.gov (United States)

    Miller, Holly H.; Hirschfeld, deceased, Tomas B.

    1991-01-01

    A method and apparatus are disclosed for the in vivo and in vitro detection and measurement of dose critical levels of DNA-binding anti-cancer drug levels in biological fluids. The apparatus comprises a laser based fiber optic sensor (optrode) which utilizes the secondary interactions between the drug and an intercalating fluorochrome bound to a probe DNA, which in turn is attached to the fiber tip at one end thereof. The other end of the optical fiber is attached to an illumination source, detector and recorder. The fluorescence intensity is measured as a function of the drug concentration and its binding constant to the probe DNA. Anticancer drugs which lend themselves to analysis by the use of the method and the optrode of the present invention include doxorubicin, daunorubicin, carminomycin, aclacinomycin, chlorambucil, cyclophosphamide, methotrexate, 5-uracil, arabinosyl cytosine, mitomycin, cis-platinum 11 diamine dichloride procarbazine, vinblastine vincristine and the like. The present method and device are suitable for the continuous monitoring of the levels of these and other anticancer drugs in biological fluids such as blood, serum, urine and the like. The optrode of the instant invention also enables the measurement of the levels of these drugs from a remote location and from multiple samples.

  2. Adrenal Vein Catecholamine Levels and Ratios: Reference Intervals Derived from Patients with Primary Aldosteronism.

    Science.gov (United States)

    Sze, Candy W C; O'Toole, Samuel Matthew; Tirador, Roger Kent; Akker, Scott A; Matson, Matthew; Perry, Leslie; Druce, Maralyn Rose; Dekkers, Tanja; Deinum, Jaap; Lenders, Jacques W M; Eisenhofer, Graeme; Drake, William Martyn

    2017-06-01

    Phaeochromocytoma localisation is generally reliably achieved with modern imaging techniques, particularly in sporadic cases. On occasion, however, there can be diagnostic doubt due to the presence of bilateral adrenal abnormalities, particularly in patients with mutations in genes predisposing them to the development of multiple phaeochromocytomas. In such cases, surgical intervention is ideally limited to large or functional lesions due to the long-term consequences associated with hypoadrenalism. Adrenal venous sampling (AVS) for catecholamines has been used in this situation to guide surgery, although there are few data available to support diagnostic thresholds. Retrospective analyses of AVS results from 2 centres were carried out. A total of 172 patients (88 men, 84 women) underwent AVS under cosyntropin stimulation for the diagnosis of established primary aldosteronism (PA) with measurement of adrenal and peripheral venous cortisol, aldosterone and catecholamines. Six patients (3 men, 3 women) with phaeochromocytoma underwent AVS for diagnostic purposes with subsequent histological confirmation. Reference intervals for the adrenal venous norepinephrine to epinephrine ratio were created from the PA group. Using the 97.5th centile (1.21 on the left, 1.04 on the right), the false negative rate in the phaeochromocytoma group was 0%. In conclusion, this study describes the largest dataset of adrenal venous catecholamine measurements and provides reference intervals in patients without phaeochromocytoma. This strengthens the certainty with which conclusions related to adrenal venous sampling for catecholamines can be drawn, acknowledging the procedure is not part of the routine diagnostic workup and is an adjunct for use only in difficult clinical cases. © Georg Thieme Verlag KG Stuttgart · New York.

  3. Dose estimation for nuclear power plant 4 accident in Taiwan at Fukushima nuclear meltdown emission level

    International Nuclear Information System (INIS)

    Tang, Mei-Ling; Tsuang, Ben-Jei; Kuo, Pei-Hsuan

    2016-01-01

    An advanced Gaussian trajectory dispersion model is used to evaluate the evacuation zone due to a nuclear meltdown at the Nuclear Power Plant 4 (NPP4) in Taiwan, with the same emission level as that occurred at Fukushima nuclear meltdown (FNM) in 2011. Our study demonstrates that a FNM emission level would pollute 9% of the island's land area with annual effective dose ≥50 mSv using the meteorological data on 11 March 2011 in Taiwan. This high dose area is also called permanent evacuation zone (denoted as PEZ). The PEZ as well as the emergency-planning zone (EPZ) are found to be sensitive to meteorological conditions on the event. In a sunny day under the dominated NE wind conditions, the EPZ can be as far as 100 km with the first 7-day dose ≥20 mSv. Three hundred sixty-five daily events using the meteorological data from 11 March 2011 to 9 March 2012 are evaluated. It is found that the mean land area of Taiwan in becoming the PEZ is 11%. Especially, the probabilities of the northern counties/cities (Keelung, New Taipei, Taipei, Taoyuan, Hsinchu City, Hsinchu County and Ilan County) to be PEZs are high, ranging from 15% in Ilan County to 51% in Keelung City. Note that the total population of the above cities/counties is as high as 10 million people. Moreover, the western valleys of the Central Mountain Range are also found to be probable being PEZs, where all of the reservoirs in western Taiwan are located. For example, the probability can be as high as 3% in the far southern-most tip of Taiwan Island in Pingtung County. This shows that the entire populations in western Taiwan can be at risk due to the shortage of clean water sources under an event at FNM emission level, especially during the NE monsoon period. - Highlights: • An advanced Gaussian-type trajectory model to evaluate the evacuation zone at Nuclear Power Plant 4 in Taiwan. • Mean land area of Taiwan in becoming the permanent evacuation zone is 11%. • The probabilities of the northern

  4. Effect of ultra-low doses, ASIR and MBIR on density and noise levels of MDCT images of dental implant sites

    Energy Technology Data Exchange (ETDEWEB)

    Widmann, Gerlig; Schullian, Peter [Medical University of Innsbruck, Department of Radiology, Innsbruck (Austria); Al-Shawaf, Reema; Al-Sadhan, Ra' ed; Al-Ekrish, Asma' a A. [King Saud University, Department of Oral Medicine and Diagnostic Sciences, College of Dentistry, Riyadh (Saudi Arabia); Hoermann, Romed [Medical University of Innsbruck, Division of Clinical and Functional Anatomy, Innsbruck (Austria)

    2017-05-15

    Differences in noise and density values in MDCT images obtained using ultra-low doses with FBP, ASIR, and MBIR may possibly affect implant site density analysis. The aim of this study was to compare density and noise measurements recorded from dental implant sites using ultra-low doses combined with FBP, ASIR, and MBIR. Cadavers were scanned using a standard protocol and four low-dose protocols. Scans were reconstructed using FBP, ASIR-50, ASIR-100, and MBIR, and either a bone or standard reconstruction kernel. Density (mean Hounsfield units [HUs]) of alveolar bone and noise levels (mean standard deviation of HUs) was recorded from all datasets and measurements were compared by paired t tests and two-way ANOVA with repeated measures. Significant differences in density and noise were found between the reference dose/FBP protocol and almost all test combinations. Maximum mean differences in HU were 178.35 (bone kernel) and 273.74 (standard kernel), and in noise, were 243.73 (bone kernel) and 153.88 (standard kernel). Decreasing radiation dose increased density and noise regardless of reconstruction technique and kernel. The effect of reconstruction technique on density and noise depends on the reconstruction kernel used. (orig.)

  5. Effect of ultra-low doses, ASIR and MBIR on density and noise levels of MDCT images of dental implant sites

    International Nuclear Information System (INIS)

    Widmann, Gerlig; Schullian, Peter; Al-Shawaf, Reema; Al-Sadhan, Ra'ed; Al-Ekrish, Asma'a A.; Hoermann, Romed

    2017-01-01

    Differences in noise and density values in MDCT images obtained using ultra-low doses with FBP, ASIR, and MBIR may possibly affect implant site density analysis. The aim of this study was to compare density and noise measurements recorded from dental implant sites using ultra-low doses combined with FBP, ASIR, and MBIR. Cadavers were scanned using a standard protocol and four low-dose protocols. Scans were reconstructed using FBP, ASIR-50, ASIR-100, and MBIR, and either a bone or standard reconstruction kernel. Density (mean Hounsfield units [HUs]) of alveolar bone and noise levels (mean standard deviation of HUs) was recorded from all datasets and measurements were compared by paired t tests and two-way ANOVA with repeated measures. Significant differences in density and noise were found between the reference dose/FBP protocol and almost all test combinations. Maximum mean differences in HU were 178.35 (bone kernel) and 273.74 (standard kernel), and in noise, were 243.73 (bone kernel) and 153.88 (standard kernel). Decreasing radiation dose increased density and noise regardless of reconstruction technique and kernel. The effect of reconstruction technique on density and noise depends on the reconstruction kernel used. (orig.)

  6. The ground level event 70 on december 13, 2006 and related effective doses at aviation altitudes

    International Nuclear Information System (INIS)

    Matthia, D.; Heber, B.; Reitz, G.; Sihver, L.; Berger, T.; Meier, M.

    2009-01-01

    The 70. ground level event in the records of the Neutron Monitor network occurred on 13 December 2006 reaching a maximum count rate increase at the Oulu station of more than 90% during the 5 min interval 3.05-3.10 UTC. Thereafter, count rates gradually decreased registering increases of a few per cent above the galactic cosmic ray background after a few hours. The primary proton spectrum during the first 6 h after the onset of the event is characterised in this work by fitting the energy and angular distribution by a power law in rigidity and a linear dependence in the pitch angle using a minimisation technique. The results were obtained by analysing the data from 28 Neutron Monitor stations. At very high northern and southern latitudes, the effective dose rates were estimated to reach values of 25-30 μSv h -1 at atmospheric depth of 200 g cm -2 during the maximum of the event. The increase in effective dose during north atlantic and polar flights was estimated to be in the order of 20%. (authors)

  7. Derived emergency reference levels for the introduction of countermeasures in the early to intermediate phases of emergencies involving the release of radioactive materials to atmosphere

    International Nuclear Information System (INIS)

    Linsley, G.S.; Crick, M.J.; Simmonds, J.R.; Haywood, S.M.

    1986-03-01

    Derived Emergency Reference Levels (DERLs) are practical quantities intended for use in the aftermath of an accident involving the release of radioactive materials to atmosphere and for use in preparing emergency plans for the protection of the public. The results of environmental measurements may be compared with them as a means of assessing the seriousness of the release and in order to form judgements on the need to institute protective countermeasures. DERLs are the practical expression of Emergency Reference Levels, the radiological criteria for planning the introduction of emergency countermeasures. DERLs have been evaluated for a range of radionuclides which could be released in the event of an accident and for a number of different exposure pathways that are relevant in the initial phase of an accident. These pathways are: inhalation of activity both in the plume and resuspended from the ground; skin irradiation by β-emitting noble gases in the cloud; doses from β-emitters deposited on the skin; and external γ irradiation from ground deposits. (author)

  8. Patient dose measurement and dose reduction in East Anglia (UK)

    International Nuclear Information System (INIS)

    Wade, J.P.; Goldstone, K.E.; Dendy, P.P.

    1995-01-01

    At the end of 1990 a programme of patient dose measurements was introduced as part of the quality assurance service already provided for X ray departments throughout the East Anglian Health Region (UK). Thermoluminescence dosemeters (TLDs) were used to measure over 1200 skin entrance surface doses for four common radiographic views in 33 hospitals in both the NHS and private sector. The four views were chosen to cover a wide range of equipment and techniques. The data collected have enabled Regional reference doses to be set which, for all views considered, fall below the National Radiological Protection Board (NRPB) Reference levels. In departments which exceeded reference levels, techniques were reviewed, improvements suggested and doses re-measured, in accordance with the recommended procedure for patient dose audit. A significant finding was that, given appropriate controls, X ray departments in the private sector could achieve the same acceptably low doses as NHS departments. (Author)

  9. A biological basis for the linear non-threshold dose-response relationship for low-level carcinogen exposure

    International Nuclear Information System (INIS)

    Albert, R.E.

    1981-01-01

    This chapter examines low-level dose-response relationships in terms of the two-stage mouse tumorigenesis model. Analyzes the feasibility of the linear non-threshold dose-response model which was first adopted for use in the assessment of cancer risks from ionizing radiation and more recently from chemical carcinogens. Finds that both the interaction of B(a)P with epidermal DNA of the mouse skin and the dose-response relationship for the initiation stage of mouse skin tumorigenesis showed a linear non-threshold dose-response relationship. Concludes that low level exposure to environmental carcinogens has a linear non-threshold dose-response relationship with the carcinogen acting as an initiator and the promoting action being supplied by the factors that are responsible for the background cancer rate in the target tissue

  10. Increased interleukin-1β levels following low dose MDMA induces tolerance against the 5-HT neurotoxicity produced by challenge MDMA

    Science.gov (United States)

    2011-01-01

    Background Preconditioning is a phenomenon by which tolerance develops to injury by previous exposure to a stressor of mild severity. Previous studies have shown that single or repeated low dose MDMA can attenuate 5-HT transporter loss produced by a subsequent neurotoxic dose of the drug. We have explored the mechanism of delayed preconditioning by low dose MDMA. Methods Male Dark Agouti rats were given low dose MDMA (3 mg/kg, i.p.) 96 h before receiving neurotoxic MDMA (12.5 mg/kg, i.p.). IL-1β and IL1ra levels and 5-HT transporter density in frontal cortex were quantified at 1 h, 3 h or 7 days. IL-1β, IL-1ra and IL-1RI were determined between 3 h and 96 h after low dose MDMA. sIL-1RI combined with low dose MDMA or IL-1β were given 96 h before neurotoxic MDMA and toxicity assessed 7 days later. Results Pretreatment with low dose MDMA attenuated both the 5-HT transporter loss and elevated IL-1β levels induced by neurotoxic MDMA while producing an increase in IL-1ra levels. Low dose MDMA produced an increase in IL-1β at 3 h and in IL-1ra at 96 h. sIL-1RI expression was also increased after low dose MDMA. Coadministration of sIL-1RI (3 μg, i.c.v.) prevented the protection against neurotoxic MDMA provided by low dose MDMA. Furthermore, IL-1β (2.5 pg, intracortical) given 96 h before neurotoxic MDMA protected against the 5-HT neurotoxicity produced by the drug, thus mimicking preconditioning. Conclusions These results suggest that IL-1β plays an important role in the development of delayed preconditioning by low dose MDMA. PMID:22114930

  11. Increased interleukin-1β levels following low dose MDMA induces tolerance against the 5-HT neurotoxicity produced by challenge MDMA

    Directory of Open Access Journals (Sweden)

    Mayado Andrea

    2011-11-01

    Full Text Available Abstract Background Preconditioning is a phenomenon by which tolerance develops to injury by previous exposure to a stressor of mild severity. Previous studies have shown that single or repeated low dose MDMA can attenuate 5-HT transporter loss produced by a subsequent neurotoxic dose of the drug. We have explored the mechanism of delayed preconditioning by low dose MDMA. Methods Male Dark Agouti rats were given low dose MDMA (3 mg/kg, i.p. 96 h before receiving neurotoxic MDMA (12.5 mg/kg, i.p.. IL-1β and IL1ra levels and 5-HT transporter density in frontal cortex were quantified at 1 h, 3 h or 7 days. IL-1β, IL-1ra and IL-1RI were determined between 3 h and 96 h after low dose MDMA. sIL-1RI combined with low dose MDMA or IL-1β were given 96 h before neurotoxic MDMA and toxicity assessed 7 days later. Results Pretreatment with low dose MDMA attenuated both the 5-HT transporter loss and elevated IL-1β levels induced by neurotoxic MDMA while producing an increase in IL-1ra levels. Low dose MDMA produced an increase in IL-1β at 3 h and in IL-1ra at 96 h. sIL-1RI expression was also increased after low dose MDMA. Coadministration of sIL-1RI (3 μg, i.c.v. prevented the protection against neurotoxic MDMA provided by low dose MDMA. Furthermore, IL-1β (2.5 pg, intracortical given 96 h before neurotoxic MDMA protected against the 5-HT neurotoxicity produced by the drug, thus mimicking preconditioning. Conclusions These results suggest that IL-1β plays an important role in the development of delayed preconditioning by low dose MDMA.

  12. Serum Creatinine Versus Plasma Methotrexate Levels to Predict Toxicities in Children Receiving High-dose Methotrexate.

    Science.gov (United States)

    Tiwari, Priya; Thomas, M K; Pathania, Subha; Dhawan, Deepa; Gupta, Y K; Vishnubhatla, Sreenivas; Bakhshi, Sameer

    2015-01-01

    Facilities for measuring methotrexate (MTX) levels are not available everywhere, potentially limiting administration of high-dose methotrexate (HDMTX). We hypothesized that serum creatinine alteration after HDMTX administration predicts MTX clearance. Overall, 122 cycles in 50 patients of non-Hodgkin lymphoma or acute lymphoblastic leukemia aged ≤18 years receiving HDMTX were enrolled prospectively. Plasma MTX levels were measured at 12, 24, 36, 48, 60, and 72 hours; serum creatinine was measured at baseline, 24, 48, and 72 hours. Correlation of plasma MTX levels with creatinine levels and changes in creatinine from baseline (Δ creatinine) were evaluated. Plasma MTX levels at 72 hours showed positive correlation with serum creatinine at 48 hours (P = .011) and 72 hours (P = .013) as also Δ creatinine at 48 hours (P = .042) and 72 hours (P = .045). However, cut-off value of either creatinine or Δ creatinine could not be established to reliably predict delayed MTX clearance. Greater than 50% Δ creatinine at 48 and 72 hours significantly predicted grade 3/4 leucopenia (P = .036 and P = .001, respectively) and thrombocytopenia (P = .012 and P = .009, respectively) but not mucositis (P = .827 and P = .910, respectively). Delayed MTX elimination did not predict any grade 3/4 toxicity. In spite of demonstration of significant correlation between serum creatinine and Δ creatinine with plasma MTX levels at 72 hours, cut-off value of either variable to predict MTX delay could not be established. Thus, either of these cannot be used as a surrogate for plasma MTX estimation. Interestingly, Δ creatinine effectively predicted hematological toxicities, which were not predicted by delayed MTX clearance.

  13. Goeckerman's therapy for psoriasis with special reference to serum pentraxin 3 level

    Energy Technology Data Exchange (ETDEWEB)

    Ctirad, A.; Lenka, B.; David, P.; Zdenek, F.; Kveta, H.; Karel, E.; Jan, K. [Charles University Prague, Hradec Kralove (Czech Republic). University Hospital

    2008-10-15

    Goeckerman's therapy (GT) of psoriasis is based on daily application of pharmacy grade coal tar on affected skin with subsequent exposure to UV light. Pentraxin 3 (PTX3) is a newly identified acute phase reactant with non redundant functions in innate immunity. PTX3 has been shown to be a reliable prognostic marker in patients with various inflammatory disorders including rheumatoid arthritis, vasculitis, and psoriasis. The aim of this study was to evaluate the influence of Goeckerman's therapy of psoriasis on levels of two pentraxins: long pentraxin PTX3 and C reactive protein in 49 patients with chronic plaque psoriasis. CRP was assessed by immunonephelometry on IMMAGE 800 (Beckman, USA). PTX3 was detected using sandwich ELISA detection set (Alexis Biochemicals, Switzerland). The serum levels of both parameters (expressed as average {+-} 1 SD) were significantly diminished after GT. The level of PTX3 dropped from 1.92 {+-} 0.72 ng/ml before GT to 1.66 {+-} 0.58 ng/ml after GT (P = 0.0396) and the level of CRP fell from 4.64 {+-} 3.93 mg/l to 1.66 {+-} 0.58 mg/l (P {lt} 0.0001). Comparing to healthy controls, the serum levels of both parameters before GT were significantly higher than those found in healthy blood donors and remained significantly increased after GT. Increased serum concentrations of pentraxin 3 and CRP are alleviated by GT in patients with psoriasis.

  14. Reference range levels of polycyclic aromatic hydrocarbons in the US population by measurement of urinary monohydroxy metabolites

    International Nuclear Information System (INIS)

    Grainger, James; Huang, Wenlin; Patterson, Donald G.; Turner, Wayman E.; Pirkle, James; Caudill, Samuel P.; Wang, Richard Y.; Needham, Larry L.; Sampson, Eric J.

    2006-01-01

    We developed a gas chromatography isotope-dilution high-resolution mass spectrometry (GC/Id-HRMS) method for measuring 14 polycyclic aromatic hydrocarbon (PAH) metabolites representing seven parent PAHs in 3 mL of urine at low parts-per-trillion levels. PAH levels were determined in urine samples collected in 1999 and 2000 from approximately 2400 participants in the National Health and Nutrition Examination Survey, and, for the first time, reference range values were calculated for these metabolites in the US population. Using this GC/ID-HRMS method, we found detectable concentrations for monohydroxy metabolite isomers of fluorene, phenanthrene, fluoranthene, pyrene, and chrysene, benzo[c]phenanthrene, and benz[a]anthracene. Some monohydroxy metabolite isomers of benzo[c]phenanthrene, chrysene, and benz[a]anthracene exhibited low detection frequencies that did not allow for geometric mean calculations. Our study results enabled us to establish a reference range for the targeted PAHs in the general US population

  15. Speakeasy-3 reference manual. Level MU. IBM OS/VS version

    International Nuclear Information System (INIS)

    Cohen, S.; Pieper, S.C.

    1977-08-01

    Speakeasy is a computer language designed to provide access to information stored in a computer. Ease of use, natural notation, and built-in capabilities for growth are important features of Speakeasy. The language is based on the concepts of arrays and matrices, and processes these as entities; the need for many of the loops necessary in other programing languages is thus eliminated. It has a large vocabulary (over 500 words) of functions and commands in the areas of array manipulation, matrix algebra including eigenanalysis, special mathematical functions, numerical integration and differentiation, statistics, graphics, and character processing. It can be used either in batch mode or interactively. This book is the primary reference manual for the Speakeasy language and presents a nearly complete description of its capabilities. The chapters deal with the use of Speakeasy as a ''super desk calculator,'' the construction and editing of Speakeasy programs, the ability to communicate with other programing languages, the construction of user-written additions to the language, and various other facets of Speakeasy. In addition, a complete listing of the Help Library, which contains brief descriptions of each of the Speakeasy functions or commands, is included. This edition applies to the Mu release of Speakeasy-3, and describes the IBM OS/VS version. 18 figures

  16. Epidemiological surveys on the effects of low-level radiation dose: a comparative assessment. Vol. A: pre-conception irradiation effects. Vol. E (DRAFT A): group collation tables

    Energy Technology Data Exchange (ETDEWEB)

    Rose, K.S.B.

    1988-01-01

    In this report, the health effects of low-level doses of radiation are considered by reference to published epidemiological surveys. The work was carried out with three objectives in mind: 1. to provide a comprehensive and critical review of the subject; 2. to seek consistent indications of particular health effects by collating results and comparing with those from surveys at moderate-level doses; 3. to provide an authoritative view on the epidemiology of low-level radiation-induced health effects. Vol E (DRAFT A) is appended and contains group collation tables. Epidemiological surveys can be conveniently divided into four classes (A, B, C, D) according to the phase of life when irradiation occurs or the effect is diagnosed. The first of the classes (A) is addressed here; this class is concerned with possible effects arising from radiation received by a parent before conception. Possible effects of preconception irradiation were identified under four broad groupings. These are Down's syndrome, ''Indicators of Reproductive Damage'' (mainly Primary Sterility, Congenital Abnormalities, Sex Ratio, Fetal Mortality, Infant Mortality), Childhood Malignancies, and Chromosomal Changes in Abortuses. Information about each survey, and comparisons with results from moderate-level dose surveys, are contained in synopses that are set out in the Appendix.

  17. Educational level and risk of colorectal cancer in EPIC with specific reference to tumor location

    NARCIS (Netherlands)

    Leufkens, Anke M.; van Duijnhoven, Fränzel J. B.; Boshuizen, Hendriek C.; Siersema, Peter D.; Kunst, Anton E.; Mouw, Traci; Tjønneland, Anne; Olsen, Anja; Overvad, Kim; Boutron-Ruault, Marie-Christine; Clavel-Chapelon, Françoise; Morois, Sophie; Krogh, Vittorio; Tumino, Rosario; Panico, Salvatore; Polidoro, Silvia; Palli, Domenico; Kaaks, Rudolf; Teucher, Birgit; Pischon, Tobias; Trichopoulou, Antonia; Orfanos, Philippos; Goufa, Ioulia; Peeters, Petra H. M.; Skeie, Guri; Braaten, Tonje; Rodríguez, Laudina; Lujan-Barroso, Leila; Sánchez-Pérez, Maria-José; Navarro, Carmen; Barricarte, Aurelio; Zackrisson, Sophia; Almquist, Martin; Hallmans, Goran; Palmqvist, Richard; Tsilidis, Konstantinos K.; Khaw, Kay-Tee; Wareham, Nick; Gallo, Valentina; Jenab, Mazda; Riboli, Elio; Bueno-de-Mesquita, H. Bas

    2012-01-01

    Existing evidence is inconclusive on whether socioeconomic status (SES) and educational inequalities influence colorectal cancer (CRC) risk, and whether low or high SES/educational level is associated with developing CRC. The aim of our study was to investigate the relationship between educational

  18. Dose-Response of High-Intensity Training (HIT) on Atheroprotective miRNA-126 Levels

    Science.gov (United States)

    Schmitz, Boris; Schelleckes, Katrin; Nedele, Johanna; Thorwesten, Lothar; Klose, Andreas; Lenders, Malte; Krüger, Michael; Brand, Eva; Brand, Stefan-Martin

    2017-01-01

    Aim: MicroRNA-126 (miR-126) exerts beneficial effects on vascular integrity, angiogenesis, and atherosclerotic plaque stability. The purpose of this investigation was to analyze the dose-response relationship of high-intensity interval training (HIIT) on miR-126-3p and -5p levels. Methods: Sixty-one moderately trained individuals (females = 31 [50.8%]; 22.0 ± 1.84 years) were consecutively recruited and allocated into three matched groups using exercise capacity. During a 4-week intervention a HIIT group performed three exercise sessions/week of 4 × 30 s at maximum speed (all-out), a progressive HIIT (proHIIT) group performed three exercise sessions/week of 4 × 30 s at maximum speed (all-out) with one extra session every week (up to 7 × 30 s) and a low-intensity training (LIT) control group performed three exercise sessions/week for 25 min HIIT groups (after 4 min of high-intensity running). After the intervention, the LIT group presented an increase in miR-126-3p, while in the HIIT group, miR-126-3p levels were still reduced (all p HIIT (−1.05 ± 2.6 units). Conclusions: LIT and proHIIT may be performed to increase individual miR-126 levels. HIIT without progression was less effective in increasing miR-126. PMID:28611681

  19. Urbanist workshops between theory and practice: The importance of spatial and programme reference levels in the planning method

    OpenAIRE

    Gregor Čok

    2013-01-01

    One of the key characteristics of urban-architectural workshops as a soft planning method is above all the fact that the authors are free of burden of formal facts and reference levels of the local environment, which do not influence the concept and the working process. Within this framework, the workshop presents an opportunity for the creator to focus primarily on the core of the problem, and work creatively towards a substantiated professional solution. In addition to the basic ref...

  20. Children and adults exposed to electromagnetic fields at the ICNIRP reference levels: theoretical assessment of the induced peak temperature increase

    Energy Technology Data Exchange (ETDEWEB)

    Bakker, J F; Paulides, M M; Van Rhoon, G C [Erasmus MC-Daniel den Hoed Cancer Center, Department of Radiation Oncology, Section Hyperthermia, PO Box 5201, NL-3008 AE, Rotterdam (Netherlands); Neufeld, E; Christ, A; Kuster, N, E-mail: j.bakker@erasmusmc.nl [Foundation for Research on Information Technologies in Society (IT' IS) (Switzerland)

    2011-08-07

    To avoid potentially adverse health effects of electromagnetic fields (EMF), the International Commission on Non-Ionizing Radiation Protection (ICNIRP) has defined EMF reference levels. Restrictions on induced whole-body-averaged specific absorption rate (SAR{sub wb}) are provided to keep the whole-body temperature increase (T{sub body,incr}) under 1 deg. C during 30 min. Additional restrictions on the peak 10 g spatial-averaged SAR (SAR{sub 10g}) are provided to prevent excessive localized tissue heating. The objective of this study is to assess the localized peak temperature increase (T{sub incr,max}) in children upon exposure at the reference levels. Finite-difference time-domain modeling was used to calculate T{sub incr,max} in six children and two adults exposed to orthogonal plane-wave configurations. We performed a sensitivity study and Monte Carlo analysis to assess the uncertainty of the results. Considering the uncertainties in the model parameters, we found that a peak temperature increase as high as 1 deg. C can occur for worst-case scenarios at the ICNIRP reference levels. Since the guidelines are deduced from temperature increase, we used T{sub incr,max} as being a better metric to prevent excessive localized tissue heating instead of localized peak SAR. However, we note that the exposure time should also be considered in future guidelines. Hence, we advise defining limits on T{sub incr,max} for specified durations of exposure.

  1. Children and adults exposed to electromagnetic fields at the ICNIRP reference levels: theoretical assessment of the induced peak temperature increase.

    Science.gov (United States)

    Bakker, J F; Paulides, M M; Neufeld, E; Christ, A; Kuster, N; van Rhoon, G C

    2011-08-07

    To avoid potentially adverse health effects of electromagnetic fields (EMF), the International Commission on Non-Ionizing Radiation Protection (ICNIRP) has defined EMF reference levels. Restrictions on induced whole-body-averaged specific absorption rate (SAR(wb)) are provided to keep the whole-body temperature increase (T(body, incr)) under 1 °C during 30 min. Additional restrictions on the peak 10 g spatial-averaged SAR (SAR(10g)) are provided to prevent excessive localized tissue heating. The objective of this study is to assess the localized peak temperature increase (T(incr, max)) in children upon exposure at the reference levels. Finite-difference time-domain modeling was used to calculate T(incr, max) in six children and two adults exposed to orthogonal plane-wave configurations. We performed a sensitivity study and Monte Carlo analysis to assess the uncertainty of the results. Considering the uncertainties in the model parameters, we found that a peak temperature increase as high as 1 °C can occur for worst-case scenarios at the ICNIRP reference levels. Since the guidelines are deduced from temperature increase, we used T(incr, max) as being a better metric to prevent excessive localized tissue heating instead of localized peak SAR. However, we note that the exposure time should also be considered in future guidelines. Hence, we advise defining limits on T(incr, max) for specified durations of exposure.

  2. Radioactive levels and doses of 3H and 14C in white spirits

    International Nuclear Information System (INIS)

    Deng, G.

    1992-01-01

    'Full Text:' White (and yeast) spirits is a general name for strong alcoholic beverages in China. The paper reports levels and doses of 3 H and 14 C in 65 spirits samples between 1986 and 1987. Experiments were made by measuring end analyzing each sample, using a low background liquid scintillation spectrometer. Radioactive levels of 65 spirits samples are as follows: Variant range of 3 H activity is 98.2 - 170.6Bq.dm -3 and its average is 149.2 ± 17.3Bq.dm -3 ; Variant range of 14 C activity is 38.8-80.2Bq.dm -3 and its average is 57.4±8.2Bq.dm -3 . If the man drinks 200cm 3 of spirits daily, the annual dose equivalents will be 0.19uSv of 3 H and 2.5uSv of 14 C . In ordinary strong alcoholic beverages that contain 57-60% alcohol, the mean 3 H and 14 C activities are 153.8Bq.dm -3 and 60.3Bq.dm -3 , respectively, but in spirits of lower alcoholic content (38-40%), the mean 3H activity is 114.6Bq.dm -3 , that is 25.5% less than ordinary spirits, and the mean 14 C activity is 46.1Bq.dm -3 , that is 23.5% less than ordinary spirits. We compared the 3 H and 14 C contents of five kinds of staple grains from both Sichuan and Guangdong provinces. We learned that the level of activity in spirits is ten times higher than in grains and water, and the level of 14 C activity in spirits is equivalent to that in grains. White spirits has fully concentrated 3 H and 14 C from both grain and water, and activities increase with increasing alcoholic content. 3 H in spirits probably is averaged from both water and grain, and 14 C is averaged mostly from grain. (author)

  3. [Personalizing the reference level: gold standard to evaluate the quality of service perceived].

    Science.gov (United States)

    Rodrigo-Rincón, I; Reyes-Pérez, M; Martínez-Lozano, M E

    2014-01-01

    To know the cutoff point at which in-house Nuclear Medicine Department (MND) customers consider that the quality of service is good (personalized cutoff). We conducted a survey of the professionals who had requested at least 5 tests to the Nuclear Medicine Department. A total of 71 doctors responded (response rate: 30%). A question was added to the questionnaire for the user to establish a cutoff point for which they would consider the quality of service as good. The quality non-conformities, areas of improvement and strong points of the six questions measuring the quality of service (Likert scale 0 to 10) were compared with two different thresholds: personalized cutoff and one proposed by the service itself a priori. Test statistics: binomial and Student's t-test for paired data. A cutoff value of 7 was proposed by the service as a reference while 68.1% of respondents suggested a cutoff above 7 points (mean 7.9 points). The 6 elements of perceived quality were considered strong points with the cutoff proposed by the MND, while there were 3 detected with the personalized threshold. Thirteen percent of the answers were nonconformities with the service cutoff versus 19.2% with the personalized one, the differences being statistically significant (difference 95% CI 6.44%:0,83-12.06). The final image of the perceived quality of an in-house customer is different when using the cutoff established by the Department versus the personalized cutoff given by the respondent. Copyright © 2013 Elsevier España, S.L. and SEMNIM. All rights reserved.

  4. Two generators to produce SI-traceable reference gas mixtures for reactive compounds at atmospheric levels

    Science.gov (United States)

    Pascale, C.; Guillevic, M.; Ackermann, A.; Leuenberger, D.; Niederhauser, B.

    2017-12-01

    To answer the needs of air quality and climate monitoring networks, two new gas generators were developed and manufactured at METAS in order to dynamically generate SI-traceable reference gas mixtures for reactive compounds at atmospheric concentrations. The technical features of the transportable generators allow for the realization of such gas standards for reactive compounds (e.g. NO2, volatile organic compounds) in the nmol · mol-1 range (ReGaS2), and fluorinated gases in the pmol ṡ mol-1 range (ReGaS3). The generation method is based on permeation and dynamic dilution. The transportable generators have multiple individual permeation chambers allowing for the generation of mixtures containing up to five different compounds. This mixture is then diluted using mass flow controllers, thus making the production process adaptable to generate the required amount of substance fraction. All parts of ReGaS2 in contact with the gas mixture are coated to reduce adsorption/desorption processes. Each input parameter required to calculate the generated amount of substance fraction is calibrated with SI-primary standards. The stability and reproducibility of the generated amount of substance fractions were tested with NO2 for ReGaS2 and HFC-125 for ReGaS3. They demonstrate stability over 1-4 d better than 0.4% and 0.8%, respectively, and reproducibility better than 0.7% and 1%, respectively. Finally, the relative expanded uncertainty of the generated amount of substance fraction is smaller than 3% with the major contributions coming from the uncertainty of the permeation rate and/or of the purity of the matrix gas. These relative expanded uncertainties meet then the needs of the data quality objectives fixed by the World Meteorological Organization.

  5. Rational reference levels for Pacific Coast radioactive pollution studies supplied by samples from northern Baja California

    International Nuclear Information System (INIS)

    Folsom, T.R.

    1974-01-01

    Background levels of radioactivity in the marine environment along the Pacific Coast are at present extremely low. However, these certainly will rise along with the growth of coastal populations and with the increased use of nuclear energy. It would be desirable to anticipate where and how fast concentrations of artificial radioactivities may reach unacceptable levels in coastal water. Successful prediction of this sort requires knowing how the ocean responds, in given regions, to specific inputs. Fortunately, some of the fate of a large class of radioactive pollutants that must be faced in the future may be inferred from careful studies during the past 20 years of the behavior of certain constituents of nuclear fallout that have entered the ocean along the coasts of California and Baja California. (CH)

  6. Use of national metrological references of dose absorbed in water and application of the IAEA TRS nr 398 dosimetry protocol to high energy photon beams. BNM-LNHB-LCIE-SFPM working group

    International Nuclear Information System (INIS)

    Chauvenet, B.; Delaunay, F.; Dolo, J.M.; Le Roy, G.; Bridier, A.; Francois, P.; Sabattier, R.

    2003-01-01

    Metrological references of dose absorbed in water for high energy photon beams used in radiotherapy have been elaborated during the past years by national calibration laboratories, and these new references are the basis of recent dosimetry protocols. However, the passage from metrological references of air kerma to dose absorbed in water, as well as the practical application of new calibration opportunities for dosemeters in high energy X ray beams requires a specific attention to maintain the consistency of dose measurement references over the hospital site. In this respect, this guide aims at the application of these metrological references. It proposes recommendations for the application of metrological references in terms of dose absorbed in water on the hospital site with reference to their determination conditions and to the implementation of the new IAEA dosimetry protocol (TRS nr 398). Thus, this guide proposes an overview of metrological references in French calibration laboratories, presents calibration methods (air kerma in a cobalt 60 gamma photon beam, dose absorbed in water) and a comparison with the IAEA TRS 277 dosimetry protocol. It addresses various practical aspects, and discusses uncertainties

  7. Study and Analysis of a Natural Reference Frame Current Controller for a Multi-Level H-Bridge Power Converter

    DEFF Research Database (Denmark)

    Ciobotaru, Mihai; Iov, Florin; Zanchetta, P.

    2008-01-01

    will be needed in order to control the power flow and to ensure proper and secure operation of this future grid with an increased level of renewable power. These power converters must be able to provide intelligent power management as well as ancillary services. This paper presents an analysis of the natural...... reference frame controller, based on proportional-resonant (PR) technique, for a multi-level H-bridge power converter for Universal and Flexible Power Management in Future Electricity Network. The proposed method is tested in terms of harmonic content in the Point of Common Coupling (PCC), voltage...

  8. Uncertainties in contamination level and in doses after exposure to actinide aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Fritsch, P.; Berard, P.; Frank, D.; Ansoborlo, E.; Fottorino, R.; Challeton-Devatayre, C.; Miele, A.; Blanchin, N.; Raynaud, P.; Piechowski, J. [CEA Cadarache, MEDOR, A. Miele, SST, 13 - Saint Paul lez Durance (France)

    2006-07-01

    A task group named 'Methodes Dosimetriques de Reference' (M.E.D.O.R.) has been created recently to provide didactic tools for dose estimation from bioassay data obtained after occupational exposure. This task group is focused on 1) application limits of the available models, 2) uncertainties in radionuclide biokinetics and in doses, and 3) identification of the main parameters involved in these uncertainties. First, uncertainties in biokinetics of {sup 239}Pu (thoracic retention and excretion) and in doses have been estimated after acute inhalation of PuO{sub 2} (A.M.A.D. 5{mu}m, type S). This was performed either when the activity of the inhaled aerosol (case 1) or the thoracic retention on day 1 (case 2) could be measured. Variability assigned to the different parameters of the ICRP models was that previously reported. After simulation, a lognormal distribution of the results was observed so that uncertainties can be expressed as 95 % Confidence interval Ratio (C.R.={sigma}{sub g}{sup 4}). In case 1, most of the uncertainties were due to aerosol deposition and remained nearly constant for 1000 days after exposure (thoracic, faecal and urinary C.R. of 8, 6 -30 and 10, respectively). In contrast, in case 2, thoracic C.R. gradually increased from 1.5 to 5, faecal C.R. was similar to that of case 1 up to 20 days and then sharply decreased to about 3, whereas C.R. of urinary excretion remained similar to case 1 throughout the 1000 day period. Uncertainties in D.P.U.I. were much higher in case 1 (C.R.=7) than in case 2 (C.R.=2) and were both mainly due to the uncertainties in thoracic equivalent doses. Second, different bioassay data were analysed to verify if the observed results were within the C.R. previously calculated for case 2. Two cases are provided as examples which appeared out of this range. The first one corresponds to an acute exposure to PuO{sub 2} aerosols which was followed for about 20 years. Fit analysis has shown a low value of the slow

  9. Uncertainties in contamination level and in doses after exposure to actinide aerosols

    International Nuclear Information System (INIS)

    Fritsch, P.; Berard, P.; Frank, D.; Ansoborlo, E.; Fottorino, R.; Challeton-Devatayre, C.; Miele, A.; Blanchin, N.; Raynaud, P.; Piechowski, J.

    2006-01-01

    A task group named 'Methodes Dosimetriques de Reference' (M.E.D.O.R.) has been created recently to provide didactic tools for dose estimation from bioassay data obtained after occupational exposure. This task group is focused on 1) application limits of the available models, 2) uncertainties in radionuclide biokinetics and in doses, and 3) identification of the main parameters involved in these uncertainties. First, uncertainties in biokinetics of 239 Pu (thoracic retention and excretion) and in doses have been estimated after acute inhalation of PuO 2 (A.M.A.D. 5μm, type S). This was performed either when the activity of the inhaled aerosol (case 1) or the thoracic retention on day 1 (case 2) could be measured. Variability assigned to the different parameters of the ICRP models was that previously reported. After simulation, a lognormal distribution of the results was observed so that uncertainties can be expressed as 95 % Confidence interval Ratio (C.R.=σ g 4 ). In case 1, most of the uncertainties were due to aerosol deposition and remained nearly constant for 1000 days after exposure (thoracic, faecal and urinary C.R. of 8, 6 -30 and 10, respectively). In contrast, in case 2, thoracic C.R. gradually increased from 1.5 to 5, faecal C.R. was similar to that of case 1 up to 20 days and then sharply decreased to about 3, whereas C.R. of urinary excretion remained similar to case 1 throughout the 1000 day period. Uncertainties in D.P.U.I. were much higher in case 1 (C.R.=7) than in case 2 (C.R.=2) and were both mainly due to the uncertainties in thoracic equivalent doses. Second, different bioassay data were analysed to verify if the observed results were within the C.R. previously calculated for case 2. Two cases are provided as examples which appeared out of this range. The first one corresponds to an acute exposure to PuO 2 aerosols which was followed for about 20 years. Fit analysis has shown a low value of the slow dissolution rate of the compound and an

  10. Quality and Dose Optimized CT Trauma Protocol - Recommendation from a University Level-I Trauma Center.

    Science.gov (United States)

    Kahn, Johannes; Kaul, David; Böning, Georg; Rotzinger, Roman; Freyhardt, Patrick; Schwabe, Philipp; Maurer, Martin H; Renz, Diane Miriam; Streitparth, Florian

    2017-09-01

    Purpose  As a supra-regional level-I trauma center, we evaluated computed tomography (CT) acquisitions of polytraumatized patients for quality and dose optimization purposes. Adapted statistical iterative reconstruction [(AS)IR] levels, tube voltage reduction as well as a split-bolus contrast agent (CA) protocol were applied. Materials and Methods  61 patients were split into 3 different groups that differed with respect to tube voltage (120 - 140 kVp) and level of applied ASIR reconstruction (ASIR 20 - 50 %). The CT protocol included a native acquisition of the head followed by a single contrast-enhanced acquisition of the whole body (64-MSCT). CA (350 mg/ml iodine) was administered as a split bolus injection of 100 ml (2 ml/s), 20 ml NaCl (1 ml/s), 60 ml (4 ml/s), 40 ml NaCl (4 ml/s) with a scan delay of 85 s to detect injuries of both the arterial system and parenchymal organs in a single acquisition. Both the quantitative (SNR/CNR) and qualitative (5-point Likert scale) image quality was evaluated in parenchymal organs that are often injured in trauma patients. Radiation exposure was assessed. Results  The use of IR combined with a reduction of tube voltage resulted in good qualitative and quantitative image quality and a significant reduction in radiation exposure of more than 40 % (DLP 1087 vs. 647 mGyxcm). Image quality could be improved due to a dedicated protocol that included different levels of IR adapted to different slice thicknesses, kernels and the examined area for the evaluation of head, lung, body and bone injury patterns. In synopsis of our results, we recommend the implementation of a polytr