Estimation of whole-body radiation exposure from brachytherapy for oral cancer using a Monte Carlo simulation

PubMed Central

Ozaki, Y.; Kaida, A.; Miura, M.; Nakagawa, K.; Toda, K.; Yoshimura, R.; Sumi, Y.; Kurabayashi, T.

2017-01-01

Abstract Early stage oral cancer can be cured with oral brachytherapy, but whole-body radiation exposure status has not been previously studied. Recently, the International Commission on Radiological Protection Committee (ICRP) recommended the use of ICRP phantoms to estimate radiation exposure from external and internal radiation sources. In this study, we used a Monte Carlo simulation with ICRP phantoms to estimate whole-body exposure from oral brachytherapy. We used a Particle and Heavy Ion Transport code System (PHITS) to model oral brachytherapy with 192Ir hairpins and 198Au grains and to perform a Monte Carlo simulation on the ICRP adult reference computational phantoms. To confirm the simulations, we also computed local dose distributions from these small sources, and compared them with the results from Oncentra manual Low Dose Rate Treatment Planning (mLDR) software which is used in day-to-day clinical practice. We successfully obtained data on absorbed dose for each organ in males and females. Sex-averaged equivalent doses were 0.547 and 0.710 Sv with 192Ir hairpins and 198Au grains, respectively. Simulation with PHITS was reliable when compared with an alternative computational technique using mLDR software. We concluded that the absorbed dose for each organ and whole-body exposure from oral brachytherapy can be estimated with Monte Carlo simulation using PHITS on ICRP reference phantoms. Effective doses for patients with oral cancer were obtained. PMID:28339846

Fluence-to-dose conversion coefficients based on the posture modification of Adult Male (AM) and Adult Female (AF) reference phantoms of ICRP 110

NASA Astrophysics Data System (ADS)

Galeano, D. C.; Santos, W. S.; Alves, M. C.; Souza, D. N.; Carvalho, A. B.

2016-04-01

The aim of this work was to modify the standing posture of the anthropomorphic reference phantoms of ICRP publication 110, AM (Adult Male) and AF (Adult Female), to the sitting posture. The change of posture was performed using the Visual Monte Carlo software (VMC) to rotate the thigh region of the phantoms and position it between the region of the leg and trunk. Scion Image software was used to reconstruct and smooth the knee and hip contours of the phantoms in a sitting posture. For 3D visualization of phantoms, the VolView software was used. In the change of postures, the organ and tissue masses were preserved. The MCNPX was used to calculate the equivalent and effective dose conversion coefficients (CCs) per fluence for photons for six irradiation geometries suggested by ICRP publication 110 (AP, PA, RLAT, LLAT, ROT and ISO) and energy range 0.010-10 MeV. The results were compared between the standing and sitting postures, for both sexes, in order to evaluate the differences of scattering and absorption of radiation for different postures. Significant differences in the CCs for equivalent dose were observed in the gonads, colon, prostate, urinary bladder and uterus, which are present in the pelvic region, and in organs distributed throughout the body, such as the lymphatic nodes, muscle, skeleton and skin, for the phantoms of both sexes. CCs for effective dose showed significant differences of up to 16% in the AP irradiation geometry, 27% in the PA irradiation geometry and 13% in the ROT irradiation geometry. These results demonstrate the importance of using phantoms in different postures in order to obtain more precise conversion coefficients for a given exposure scenario.

Fluence-to-dose conversion coefficients for heavy ions calculated using the PHITS code and the ICRP/ICRU adult reference computational phantoms.

PubMed

Sato, Tatsuhiko; Endo, Akira; Niita, Koji

2010-04-21

The fluence to organ-absorbed-dose and effective-dose conversion coefficients for heavy ions with atomic numbers up to 28 and energies from 1 MeV/nucleon to 100 GeV/nucleon were calculated using the PHITS code coupled to the ICRP/ICRU adult reference computational phantoms, following the instruction given in ICRP Publication 103 (2007 (Oxford: Pergamon)). The conversion coefficients for effective dose equivalents derived using the radiation quality factors of both Q(L) and Q(y) relationships were also estimated, utilizing the functions for calculating the probability densities of absorbed dose in terms of LET (L) and lineal energy (y), respectively, implemented in PHITS. The calculation results indicate that the effective dose can generally give a conservative estimation of the effective dose equivalent for heavy-ion exposure, although it is occasionally too conservative especially for high-energy lighter-ion irradiations. It is also found from the calculation that the conversion coefficients for the Q(y)-based effective dose equivalents are generally smaller than the corresponding Q(L)-based values because of the conceptual difference between LET and y as well as the numerical incompatibility between the Q(L) and Q(y) relationships. The calculated data of these dose conversion coefficients are very useful for the dose estimation of astronauts due to cosmic-ray exposure.

Organ and effective dose coefficients for cranial and caudal irradiation geometries: photons

DOE PAGES

Veinot, K. G.; Eckerman, K. F.; Hertel, N. E.

2015-05-02

With the introduction of new recommendations of the International Commission on Radiological Protection (ICRP) in Publication 103, the methodology for determining the protection quantity, effective dose, has been modified. The modifications include changes to the defined organs and tissues, the associated tissue weighting factors, radiation weighting factors and the introduction of reference sex-specific computational phantoms. Computations of equivalent doses in organs and tissues are now performed in both the male and female phantoms and the sex-averaged values used to determine the effective dose. Dose coefficients based on the ICRP 103 recommendations were reported in ICRP Publication 116, the revision ofmore » ICRP Publication 74 and ICRU Publication 57. The coefficients were determined for the following irradiation geometries: anterior-posterior (AP), posterior-anterior (PA), right and left lateral (RLAT and LLAT), rotational (ROT) and isotropic (ISO). In this work, the methodology of ICRP Publication 116 was used to compute dose coefficients for photon irradiation of the body with parallel beams directed upward from below the feet (caudal) and directed downward from above the head (cranial). These geometries may be encountered in the workplace from personnel standing on contaminated surfaces or volumes and from overhead sources. Calculations of organ and tissue kerma and absorbed doses for caudal and cranial exposures to photons ranging in energy from 10 keV to 10 GeV have been performed using the MCNP6.1 radiation transport code and the adult reference phantoms of ICRP Publication 110. As with calculations reported in ICRP 116, the effects of charged-particle transport are evident when compared with values obtained by using the kerma approximation. At lower energies the effective dose per particle fluence for cranial and caudal exposures is less than AP orientations while above similar to 30 MeV the cranial and caudal values are greater.« less

Organ and effective dose coefficients for cranial and caudal irradiation geometries: photons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Veinot, K. G.; Eckerman, K. F.; Hertel, N. E.

With the introduction of new recommendations of the International Commission on Radiological Protection (ICRP) in Publication 103, the methodology for determining the protection quantity, effective dose, has been modified. The modifications include changes to the defined organs and tissues, the associated tissue weighting factors, radiation weighting factors and the introduction of reference sex-specific computational phantoms. Computations of equivalent doses in organs and tissues are now performed in both the male and female phantoms and the sex-averaged values used to determine the effective dose. Dose coefficients based on the ICRP 103 recommendations were reported in ICRP Publication 116, the revision ofmore » ICRP Publication 74 and ICRU Publication 57. The coefficients were determined for the following irradiation geometries: anterior-posterior (AP), posterior-anterior (PA), right and left lateral (RLAT and LLAT), rotational (ROT) and isotropic (ISO). In this work, the methodology of ICRP Publication 116 was used to compute dose coefficients for photon irradiation of the body with parallel beams directed upward from below the feet (caudal) and directed downward from above the head (cranial). These geometries may be encountered in the workplace from personnel standing on contaminated surfaces or volumes and from overhead sources. Calculations of organ and tissue kerma and absorbed doses for caudal and cranial exposures to photons ranging in energy from 10 keV to 10 GeV have been performed using the MCNP6.1 radiation transport code and the adult reference phantoms of ICRP Publication 110. As with calculations reported in ICRP 116, the effects of charged-particle transport are evident when compared with values obtained by using the kerma approximation. At lower energies the effective dose per particle fluence for cranial and caudal exposures is less than AP orientations while above similar to 30 MeV the cranial and caudal values are greater.« less

Consideration of the ICRP 2006 revised tissue weighting factors on age-dependent values of the effective dose for external photons

NASA Astrophysics Data System (ADS)

Lee, Choonsik; Lee, Choonik; Han, Eun Young; Bolch, Wesley E.

2007-01-01

The effective dose recommended by the International Commission on Radiological Protection (ICRP) is the sum of organ equivalent doses weighted by corresponding tissue weighting factors, wT. ICRP is in the process of revising its 1990 recommendations on the effective dose where new values of organs and tissue weighting factors have been proposed and published in draft form for consultation by the radiological protection community. In its 5 June 2006 draft recommendations, new organs and tissues have been introduced in the effective dose which do not exist within the 1987 Oak Ridge National Laboratory (ORNL) phantom series (e.g., salivary glands). Recently, the investigators at University of Florida have updated the series of ORNL phantoms by implementing new organ models and adopting organ-specific elemental composition and densities. In this study, the effective dose changes caused by the transition from the current recommendation of ICRP Publication 60 to the 2006 draft recommendations were investigated for external photon irradiation across the range of ICRP reference ages (newborn, 1-year, 5-year, 10-year, 15-year and adult) and for six idealized irradiation geometries: anterior-posterior (AP), posterior-anterior (PA), left-lateral (LLAT), right-lateral (RLAT), rotational (ROT) and isotropic (ISO). Organ-absorbed doses were calculated by implementing the revised ORNL phantoms in the Monte Carlo radiation transport code, MCNPX2.5, after which effective doses were calculated under the 1990 and draft 2006 evaluation schemes of the ICRP. Effective doses calculated under the 2006 draft scheme were slightly higher than estimated under ICRP Publication 60 methods for all irradiation geometries exclusive of the AP geometry where an opposite trend was observed. The effective doses of the adult phantom were more greatly affected by the change in tissue weighting factors than that seen within the paediatric members of the phantom series. Additionally, dose conversion coefficients for newly identified radiosensitive organs—salivary glands, gall bladder, heart and prostate—were reported, as well as the brain, which was originally considered in ICRP Publication 60 as a member of the remainder category of the effective dose.

Estimation of whole-body radiation exposure from brachytherapy for oral cancer using a Monte Carlo simulation.

PubMed

Ozaki, Y; Watanabe, H; Kaida, A; Miura, M; Nakagawa, K; Toda, K; Yoshimura, R; Sumi, Y; Kurabayashi, T

2017-07-01

Early stage oral cancer can be cured with oral brachytherapy, but whole-body radiation exposure status has not been previously studied. Recently, the International Commission on Radiological Protection Committee (ICRP) recommended the use of ICRP phantoms to estimate radiation exposure from external and internal radiation sources. In this study, we used a Monte Carlo simulation with ICRP phantoms to estimate whole-body exposure from oral brachytherapy. We used a Particle and Heavy Ion Transport code System (PHITS) to model oral brachytherapy with 192Ir hairpins and 198Au grains and to perform a Monte Carlo simulation on the ICRP adult reference computational phantoms. To confirm the simulations, we also computed local dose distributions from these small sources, and compared them with the results from Oncentra manual Low Dose Rate Treatment Planning (mLDR) software which is used in day-to-day clinical practice. We successfully obtained data on absorbed dose for each organ in males and females. Sex-averaged equivalent doses were 0.547 and 0.710 Sv with 192Ir hairpins and 198Au grains, respectively. Simulation with PHITS was reliable when compared with an alternative computational technique using mLDR software. We concluded that the absorbed dose for each organ and whole-body exposure from oral brachytherapy can be estimated with Monte Carlo simulation using PHITS on ICRP reference phantoms. Effective doses for patients with oral cancer were obtained. © The Author 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

In vivo organ mass of Korean adults obtained from whole-body magnetic resonance data.

PubMed

Park, S; Lee, J K; Kim, J I; Lee, Y J; Lim, Y K; Kim, C S; Lee, C

2006-01-01

In vivo organ mass of the Korean adult, male and female were presented for the purpose of radiation protection. A total of 121 healthy volunteers (66 males and 55 females), whose body dimensions were close to that of average Korean adults, were recruited for this study. Whole-body magnetic resonance (MR) images were obtained, and contours of 15 organs (brain, eye, gall bladder, heart, kidney, liver, lung, pancreas, stomach, spleen, testes, thymus, thyroid, urinary bladder and uterus) and 9 bones (femur, tibia + fibula, humerus, radius + ulna, pelvis, cervical spine, thoracic and lumber spine, skull and clavicle) were segmented for organ volume rendering by anatomists using commercial software. Organ and bone masses were calculated by multiplying the Asian reference densities of the corresponding organs and bones by the measured volumes. The resulting organ and bone masses were compared with those of the International Commission of Radiological Protection (ICRP) and the Asian reference data. Significantly large standard deviation was shown in the moving organs of the respiratory and circulatory systems and in the alimentary and urogenital organs that are variable in volume in a single person. Gall bladder and pancreas showed unique Korean organ masses compared with those of ICRP and the Asian reference adults. Different from anatomical data based on autopsy, the in vivo volume and mass in this study can more exactly describe the organ volume of a living human subject for radiation protection. A larger sample size would be required for obtaining statistically more reliable results. It is also needed to establish the reference organ mass of younger age groups for which it is difficult to recruit volunteers and to immobilise the subjects for long-time MR scanning. At present, the data from this study will contribute to the establishment of a Korean reference database.

Dose estimation for astronauts using dose conversion coefficients calculated with the PHITS code and the ICRP/ICRU adult reference computational phantoms.

PubMed

Sato, Tatsuhiko; Endo, Akira; Sihver, Lembit; Niita, Koji

2011-03-01

Absorbed-dose and dose-equivalent rates for astronauts were estimated by multiplying fluence-to-dose conversion coefficients in the units of Gy.cm(2) and Sv.cm(2), respectively, and cosmic-ray fluxes around spacecrafts in the unit of cm(-2) s(-1). The dose conversion coefficients employed in the calculation were evaluated using the general-purpose particle and heavy ion transport code system PHITS coupled to the male and female adult reference computational phantoms, which were released as a common ICRP/ICRU publication. The cosmic-ray fluxes inside and near to spacecrafts were also calculated by PHITS, using simplified geometries. The accuracy of the obtained absorbed-dose and dose-equivalent rates was verified by various experimental data measured both inside and outside spacecrafts. The calculations quantitatively show that the effective doses for astronauts are significantly greater than their corresponding effective dose equivalents, because of the numerical incompatibility between the radiation quality factors and the radiation weighting factors. These results demonstrate the usefulness of dose conversion coefficients in space dosimetry. © Springer-Verlag 2010

Comparison of Monoenergetic Photon Organ Dose Rate Coefficients for the Female Stylized and Voxel Phantoms Submerged in Air

DOE PAGES

Hiller, Mauritius; Dewji, Shaheen Azim

2017-02-16

Dose rate coefficients computed using the International Commission on Radiological Protection (ICRP) reference adult female voxel phantom were compared with values computed using the Oak Ridge National Laboratory (ORNL) adult female stylized phantom in an air submersion exposure geometry. This is a continuation of previous work comparing monoenergetic organ dose rate coefficients for the male adult phantoms. With both the male and female data computed, effective dose rate as defined by ICRP Publication 103 was compared for both phantoms. Organ dose rate coefficients for the female phantom and ratios of organ dose rates for the voxel and stylized phantoms aremore » provided in the energy range from 30 to 5 MeV. Analysis of the contribution of the organs to effective dose is also provided. Lastly, comparison of effective dose rates between the voxel and stylized phantoms was within 8% at 100 keV and is <5% between 200 and 5000 keV.« less

Comparison of Monoenergetic Photon Organ Dose Rate Coefficients for the Female Stylized and Voxel Phantoms Submerged in Air

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hiller, Mauritius; Dewji, Shaheen Azim

Dose rate coefficients computed using the International Commission on Radiological Protection (ICRP) reference adult female voxel phantom were compared with values computed using the Oak Ridge National Laboratory (ORNL) adult female stylized phantom in an air submersion exposure geometry. This is a continuation of previous work comparing monoenergetic organ dose rate coefficients for the male adult phantoms. With both the male and female data computed, effective dose rate as defined by ICRP Publication 103 was compared for both phantoms. Organ dose rate coefficients for the female phantom and ratios of organ dose rates for the voxel and stylized phantoms aremore » provided in the energy range from 30 to 5 MeV. Analysis of the contribution of the organs to effective dose is also provided. Lastly, comparison of effective dose rates between the voxel and stylized phantoms was within 8% at 100 keV and is <5% between 200 and 5000 keV.« less

The UF family of reference hybrid phantoms for computational radiation dosimetry

NASA Astrophysics Data System (ADS)

Lee, Choonsik; Lodwick, Daniel; Hurtado, Jorge; Pafundi, Deanna; Williams, Jonathan L.; Bolch, Wesley E.

2010-01-01

Computational human phantoms are computer models used to obtain dose distributions within the human body exposed to internal or external radiation sources. In addition, they are increasingly used to develop detector efficiencies for in vivo whole-body counters. Two classes of computational human phantoms have been widely utilized for dosimetry calculation: stylized and voxel phantoms that describe human anatomy through mathematical surface equations and 3D voxel matrices, respectively. Stylized phantoms are flexible in that changes to organ position and shape are possible given avoidance of region overlap, while voxel phantoms are typically fixed to a given patient anatomy, yet can be proportionally scaled to match individuals of larger or smaller stature, but of equivalent organ anatomy. Voxel phantoms provide much better anatomical realism as compared to stylized phantoms which are intrinsically limited by mathematical surface equations. To address the drawbacks of these phantoms, hybrid phantoms based on non-uniform rational B-spline (NURBS) surfaces have been introduced wherein anthropomorphic flexibility and anatomic realism are both preserved. Researchers at the University of Florida have introduced a series of hybrid phantoms representing the ICRP Publication 89 reference newborn, 15 year, and adult male and female. In this study, six additional phantoms are added to the UF family of hybrid phantoms—those of the reference 1 year, 5 year and 10 year child. Head and torso CT images of patients whose ages were close to the targeted ages were obtained under approved protocols. Major organs and tissues were segmented from these images using an image processing software, 3D-DOCTOR™. NURBS and polygon mesh surfaces were then used to model individual organs and tissues after importing the segmented organ models to the 3D NURBS modeling software, Rhinoceros™. The phantoms were matched to four reference datasets: (1) standard anthropometric data, (2) reference organ masses from ICRP Publication 89, (3) reference elemental compositions provided in ICRP 89 as well as ICRU Report 46, and (4) reference data on the alimentary tract organs given in ICRP Publications 89 and 100. Various adjustments and refinements to the organ systems of the previously described newborn, 15 year and adult phantoms are also presented. The UF series of hybrid phantoms retain the non-uniform scalability of stylized phantoms while maintaining the anatomical realism of patient-specific voxel phantoms with respect to organ shape, depth and inter-organ distance. While the final versions of these phantoms are in a voxelized format for radiation transport simulation, their primary format is given as NURBS and polygon mesh surfaces, thus permitting one to sculpt non-reference phantoms using the reference phantoms as an anatomic template.

Management of radon: a review of ICRP recommendations.

PubMed

Vaillant, Ludovic; Bataille, Céline

2012-09-01

This article proposes a review of past and current ICRP publications dealing with the management of radon exposures. Its main objective is to identify and discuss the driving factors that have been used by the Commission during the last 50 years so as to better appreciate current issues regarding radon exposure management. The analysis shows that major evolutions took place in very recent years. As far as the management of radon exposures is concerned, ICRP recommended, until ICRP Publication 103 (ICRP 2007 ICRP Publication 103; Ann. ICRP 37), to use action levels and to consider only exposures above these levels. The Commission has reviewed its approach and now proposes to manage any radon exposure through the application of the optimisation principle and associated reference levels. As far as the assessment of the radon risk is concerned, it appears that the successive changes made by ICRP did not have a strong impact on the values of radon gas concentration recommended as action levels either in dwellings or in workplaces. The major change occurred in late 2009 with the publication of the ICRP Statement on Radon, which acknowledged that the radon risk has been underestimated by a factor of 2, thus inducing a major revision of radon reference levels.

Analysis of Mass Averaged Tissue Doses in CAM, CAF, MAX, and FAX

NASA Technical Reports Server (NTRS)

Slaba, Tony C.; Qualls, Garry D.; Clowdsley, Martha S.; Blattnig, Steve R.; Simonsen, Lisa C.; Walker, Steven A.; Singleterry, Robert C.

2009-01-01

To estimate astronaut health risk due to space radiation, one must have the ability to calculate exposure-related quantities averaged over specific organs and tissue types. In this study, we first examine the anatomical properties of the Computerized Anatomical Man (CAM), Computerized Anatomical Female (CAF), Male Adult voXel (MAX), and Female Adult voXel (FAX) models by comparing the masses of various tissues to the reference values specified by the International Commission on Radiological Protection (ICRP). Major discrepancies are found between the CAM and CAF tissue masses and the ICRP reference data for almost all of the tissues. We next examine the distribution of target points used with the deterministic transport code HZETRN to compute mass averaged exposure quantities. A numerical algorithm is used to generate multiple point distributions for many of the effective dose tissues identified in CAM, CAF, MAX, and FAX. It is concluded that the previously published CAM and CAF point distributions were under-sampled and that the set of point distributions presented here should be adequate for future studies involving CAM, CAF, MAX, or FAX. It is concluded that MAX and FAX are more accurate than CAM and CAF for space radiation analyses.

The mandate and work of ICRP Committee 3 on radiological protection in medicine.

PubMed

Miller, D L; Martin, C J; Rehani, M M

2018-01-01

The mandate of Committee 3 of the International Commission on Radiological Protection (ICRP) is concerned with the protection of persons and unborn children when ionising radiation is used in medical diagnosis, therapy, and biomedical research. Protection in veterinary medicine has been newly added to the mandate. Committee 3 develops recommendations and guidance in these areas. The most recent documents published by ICRP that relate to radiological protection in medicine are 'Radiological protection in cone beam computed tomography' (ICRP Publication 129) and 'Radiological protection in ion beam radiotherapy' (ICRP Publication 127). A report in cooperation with ICRP Committee 2 entitled 'Radiation dose to patients from radiopharmaceuticals: a compendium of current information related to frequently used substances' (ICRP Publication 128) has also been published. 'Diagnostic reference levels in medical imaging' (ICRP Publication 135), published in 2017, provides specific advice on the setting and use of diagnostic reference levels for diagnostic and interventional radiology, digital imaging, computed tomography, nuclear medicine, paediatrics, and multi-modality procedures. 'Occupational radiological protection in interventional procedures' was published in March 2018 as ICRP Publication 139. A document on radiological protection in therapy with radiopharmaceuticals is likely to be published in 2018. Work is in progress on several other topics, including appropriate use of effective dose in collaboration with the other ICRP committees, guidance for occupational radiological protection in brachytherapy, justification in medical imaging, and radiation doses to patients from radiopharmaceuticals (an update to ICRP Publication 128). Committee 3 is also considering the development of guidance on radiological protection in medicine related to individual radiosusceptibility, in collaboration with ICRP Committee 1.

Organ and effective dose coefficients for cranial and caudal irradiation geometries: Neutrons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Veinot, K. G.; Eckerman, K. F.; Hertel, N. E.

Dose coefficients based on the recommendations of International Commission on Radiological Protection (ICRP) Publication 103 were reported in ICRP Publication 116, the revision of ICRP Publication 74 and ICRU Publication 57 for the six reference irradiation geometries: anterior–posterior, posterior–anterior, right and left lateral, rotational and isotropic. In this work, dose coefficients for neutron irradiation of the body with parallel beams directed upward from below the feet (caudal) and downward from above the head (cranial) using the ICRP 103 methodology were computed using the MCNP 6.1 radiation transport code. The dose coefficients were determined for neutrons ranging in energy from 10more » –9 MeV to 10 GeV. Here, at energies below about 500 MeV, the cranial and caudal dose coefficients are less than those for the six reference geometries reported in ICRP Publication 116.« less

Organ and effective dose coefficients for cranial and caudal irradiation geometries: Neutrons

DOE PAGES

Veinot, K. G.; Eckerman, K. F.; Hertel, N. E.; ...

2016-08-29

Dose coefficients based on the recommendations of International Commission on Radiological Protection (ICRP) Publication 103 were reported in ICRP Publication 116, the revision of ICRP Publication 74 and ICRU Publication 57 for the six reference irradiation geometries: anterior–posterior, posterior–anterior, right and left lateral, rotational and isotropic. In this work, dose coefficients for neutron irradiation of the body with parallel beams directed upward from below the feet (caudal) and downward from above the head (cranial) using the ICRP 103 methodology were computed using the MCNP 6.1 radiation transport code. The dose coefficients were determined for neutrons ranging in energy from 10more » –9 MeV to 10 GeV. Here, at energies below about 500 MeV, the cranial and caudal dose coefficients are less than those for the six reference geometries reported in ICRP Publication 116.« less

Basic anatomical and physiological data for use in radiological protection: reference values. A report of age- and gender-related differences in the anatomical and physiological characteristics of reference individuals. ICRP Publication 89.

PubMed

2002-01-01

This report presents detailed information on age- and gender-related differences in the anatomical and physiological characteristics of reference individuals. These reference values provide needed input to prospective dosimetry calculations for radiation protection purposes for both workers and members of the general public. The purpose of this report is to consolidate and unify in one publication, important new information on reference anatomical and physiological values that has become available since Publication 23 was published by the ICRP in 1975. There are two aspects of this work. The first is to revise and extend the information in Publication 23 as appropriate. The second is to provide additional information on individual variation among grossly normal individuals resulting from differences in age, gender, race, or other factors. This publication collects, unifies, and expands the updated ICRP reference values for the purpose of providing a comprehensive and consistent set of age- and gender-specific reference values for anatomical and physiological features of the human body pertinent to radiation dosimetry. The reference values given in this report are based on: (a) anatomical and physiological information not published before by the ICRP; (b) recent ICRP publications containing reference value information; and (c) information in Publication 23 that is still considered valid and appropriate for radiation protection purposes. Moving from the past emphasis on 'Reference Man', the new report presents a series of reference values for both male and female subjects of six different ages: newborn, 1 year, 5 years, 10 years, 15 years, and adult. In selecting reference values, the Commission has used data on Western Europeans and North Americans because these populations have been well studied with respect to antomy, body composition, and physiology. When appropriate, comparisons are made between the chosen reference values and data from several Asian populations. The first section of the report provides summary tables of all the anatomical and physiological parameters given as reference values in this publication. These results give a comprehensive view of reference values for an individual as influenced by age and gender. The second section describes characteristics of dosimetric importance for the embryo and fetus. Information is provided on the development of the total body and the timing of appearance and development of the various organ systems. Reference values are provided on the mass of the total body and selected organs and tissues, as well as a number of physiological parameters. The third section deals with reference values of important anatomical and physiological characteristics of reference individuals from birth to adulthood. This section begins with details on the growth and composition of the total body in males and females. It then describes and quantifies anatomical and physiological characteristics of various organ systems and changes in these characteristics during growth, maturity, and pregnancy. Reference values are specified for characteristics of dosimetric importance. The final section gives a brief summary of the elemental composition of individuals. Focusing on the elements of dosimetric importance, information is presented on the body content of 13 elements: calcium, carbon, chloride, hydrogen, iodine, iron, magnesium, nitrogen, oxygen, potassium, sodium, sulphur, and phosphorus.

NCICT: a computational solution to estimate organ doses for pediatric and adult patients undergoing CT scans.

PubMed

Lee, Choonsik; Kim, Kwang Pyo; Bolch, Wesley E; Moroz, Brian E; Folio, Les

2015-12-01

We developed computational methods and tools to assess organ doses for pediatric and adult patients undergoing computed tomography (CT) examinations. We used the International Commission on Radiological Protection (ICRP) reference pediatric and adult phantoms combined with the Monte Carlo simulation of a reference CT scanner to establish comprehensive organ dose coefficients (DC), organ absorbed dose per unit volumetric CT Dose Index (CTDIvol) (mGy/mGy). We also developed methods to estimate organ doses with tube current modulation techniques and size specific dose estimates. A graphical user interface was designed to obtain user input of patient- and scan-specific parameters, and to calculate and display organ doses. A batch calculation routine was also integrated into the program to automatically calculate organ doses for a large number of patients. We entitled the computer program, National Cancer Institute dosimetry system for CT(NCICT). We compared our dose coefficients with those from CT-Expo, and evaluated the performance of our program using CT patient data. Our pediatric DCs show good agreements of organ dose estimation with those from CT-Expo except for thyroid. Our results support that the adult phantom in CT-Expo seems to represent a pediatric individual between 10 and 15 years rather than an adult. The comparison of CTDIvol values between NCICT and dose pages from 10 selected CT scans shows good agreements less than 12% except for two cases (up to 20%). The organ dose comparison between mean and modulated mAs shows that mean mAs-based calculation significantly overestimates dose (up to 2.4-fold) to the organs in close proximity to lungs in chest and chest-abdomen-pelvis scans. Our program provides more realistic anatomy based on the ICRP reference phantoms, higher age resolution, the most up-to-date bone marrow dosimetry, and several convenient features compared to previous tools. The NCICT will be available for research purpose in the near future.

Age-specific inhalation radiation dose commitment factors for selected radionuclides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strenge, D.L.; Peloquin, R.A.; Baker, D.A.

Inhalation dose commitment factors are presented for selected radionuclides for exposure of individuals in four age groups: infant, child, teen and adult. Radionuclides considered are /sup 35/S, /sup 36/Cl, /sup 45/Ca, /sup 67/Ga, /sup 75/Se, /sup 85/Sr, /sup 109/Cd, /sup 113/Sn, /sup 125/I, /sup 133/Ba, /sup 170/Tm, /sup 169/Yb, /sup 182/Ta, /sup 192/Ir, /sup 198/Au, /sup 201/Tl, /sup 204/Tl, and /sup 236/Pu. The calculational method is based on the human metabolic model of ICRP as defined in Publication 2 (ICRP 1959) and as used in previous age-specific dose factor calculations by Hoenes and Soldat (1977). Dose commitment factors are presentedmore » for the following organs of reference: total body, bone, liver, kidney, thyroid, lung and lower large intestine.« less

Dosimetric models of the eye and lens of the eye and their use in assessing dose coefficients for ocular exposures.

PubMed

Bolch, W E; Dietze, G; Petoussi-Henss, N; Zankl, M

2015-06-01

Based upon recent epidemiological studies of ocular exposure, the Main Commission of the International Commission on Radiological Protection (ICRP) in ICRP Publication 118 states that the threshold dose for radiation-induced cataracts is now considered to be approximately 0.5 Gy for both acute and fractionated exposures. Consequently, a reduction was also recommended for the occupational annual equivalent dose to the lens of the eye from 150 mSv to 20 mSv, averaged over defined periods of 5 years. To support ocular dose assessment and optimisation, Committee 2 included Annex F within ICRP Publication 116 . Annex F provides dose coefficients - absorbed dose per particle fluence - for photon, electron, and neutron irradiation of the eye and lens of the eye using two dosimetric models. The first approach uses the reference adult male and female voxel phantoms of ICRP Publication 110. The second approach uses the stylised eye model of Behrens et al., which itself is based on ocular dimensional data given in Charles and Brown. This article will review the data and models of Annex F with particular emphasis on how these models treat tissue regions thought to be associated with stem cells at risk. © The International Society for Prosthetics and Orthotics Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

RPI-AM and RPI-AF, a pair of mesh-based, size-adjustable adult male and female computational phantoms using ICRP-89 parameters and their calculations for organ doses from monoenergetic photon beams

NASA Astrophysics Data System (ADS)

Zhang, Juying; Hum Na, Yong; Caracappa, Peter F.; Xu, X. George

2009-10-01

This paper describes the development of a pair of adult male and adult female computational phantoms that are compatible with anatomical parameters for the 50th percentile population as specified by the International Commission on Radiological Protection (ICRP). The phantoms were designed entirely using polygonal mesh surfaces—a Boundary REPresentation (BREP) geometry that affords the ability to efficiently deform the shape and size of individual organs, as well as the body posture. A set of surface mesh models, from Anatomium™ 3D P1 V2.0, including 140 organs (out of 500 available) was adopted to supply the basic anatomical representation at the organ level. The organ masses were carefully adjusted to agree within 0.5% relative error with the reference values provided in the ICRP Publication 89. The finalized phantoms have been designated the RPI adult male (RPI-AM) and adult female (RPI-AF) phantoms. For the purposes of organ dose calculations using the MCNPX Monte Carlo code, these phantoms were subsequently converted to voxel formats. Monoenergetic photons between 10 keV and 10 MeV in six standard external photon source geometries were considered in this study: four parallel beams (anterior-posterior, posterior-anterior, left lateral and right lateral), one rotational and one isotropic. The results are tabulated as fluence-to-organ-absorbed-dose conversion coefficients and fluence-to-effective-dose conversion coefficients and compared against those derived from the ICRP computational phantoms, REX and REGINA. A general agreement was found for the effective dose from these two sets of phantoms for photon energies greater than about 300 keV. However, for low-energy photons and certain individual organs, the absorbed doses exhibit profound differences due to specific anatomical features. For example, the position of the arms affects the dose to the lung by more than 20% below 300 keV in the lateral source directions, and the vertical position of the testes affects the dose by more than 80% below 150 keV in the PA source direction. The deformability and adjustability of organs and posture in the RPI adult phantoms may prove useful not only for average workers or patients for radiation protection purposes, but also in studies involving anatomical and posture variability that is important in future radiation protection dosimetry.

The reference individual of radiation protection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eckerman, K.F.; Cristy, M.

1995-12-31

The 70-kg {open_quotes}standard man{close_quotes} representing a typical Western adult male has been used in physiological models since at least the 1920s. In 1949 at the Chalk River conference, health physicists from the U.S., UK, and Canada agreed on the concept of a standard man to facilitate comparison of internal dose estimates. The 70-kg standard man included specifications of the masses of 25 organs and tissues, total body content of 15 elements, total water intake and output, water content of the body, and some anatomical and physiological data for the respiratory and gastrointestinal tracts. In 1959, in its Publication 2{sup 2}more » on permissible doses for internal radiation the International Commission on Radiological Protection (ICRP) modified standard man. In 1963 the ICRP established a task group to revise and extend the standard man concept. The name was changed later to Reference Man and the task group`s work was published in 1975 as ICRP Publication 23{sup 3}. Publication 23 similar to Publication 2, updates and documents the sources of the data. Data on women, children, and fetuses were also collected, where available, but these data were limited primarily to anatomical data and only a few reference values were established for these groups. Information assembled during the course of the effort on the Reference Man report was used at Oak Ridge National Laboratory (ORNL) to construct a mathematical representation of the body (a phantom) that was suitable for use with Monte Carlo methods in the calculation of organ doses. That effort was undertaken to improve estimates of dose from photon-emitting radionuclides residing within organs, so-called internal emitters. The phantom, although updated throughout the years, remains today as the basis for organ dose estimates in nuclear medicine and radiation protection and underlies the radiation risk data derived from the epidemiologic studies of the atomic bomb survivors of Hiroshima and Nagasaki.« less

An image-based skeletal tissue model for the ICRP reference newborn

NASA Astrophysics Data System (ADS)

Pafundi, Deanna; Lee, Choonsik; Watchman, Christopher; Bourke, Vincent; Aris, John; Shagina, Natalia; Harrison, John; Fell, Tim; Bolch, Wesley

2009-07-01

Hybrid phantoms represent a third generation of computational models of human anatomy needed for dose assessment in both external and internal radiation exposures. Recently, we presented the first whole-body hybrid phantom of the ICRP reference newborn with a skeleton constructed from both non-uniform rational B-spline and polygon-mesh surfaces (Lee et al 2007 Phys. Med. Biol. 52 3309-33). The skeleton in that model included regions of cartilage and fibrous connective tissue, with the remainder given as a homogenous mixture of cortical and trabecular bone, active marrow and miscellaneous skeletal tissues. In the present study, we present a comprehensive skeletal tissue model of the ICRP reference newborn to permit a heterogeneous representation of the skeleton in that hybrid phantom set—both male and female—that explicitly includes a delineation of cortical bone so that marrow shielding effects are correctly modeled for low-energy photons incident upon the newborn skeleton. Data sources for the tissue model were threefold. First, skeletal site-dependent volumes of homogeneous bone were obtained from whole-cadaver CT image analyses. Second, selected newborn bone specimens were acquired at autopsy and subjected to micro-CT image analysis to derive model parameters of the marrow cavity and bone trabecular 3D microarchitecture. Third, data given in ICRP Publications 70 and 89 were selected to match reference values on total skeletal tissue mass. Active marrow distributions were found to be in reasonable agreement with those given previously by the ICRP. However, significant differences were seen in total skeletal and site-specific masses of trabecular and cortical bone between the current and ICRP newborn skeletal tissue models. The latter utilizes an age-independent ratio of 80%/20% cortical and trabecular bone for the reference newborn. In the current study, a ratio closer to 40%/60% is used based upon newborn CT and micro-CT skeletal image analyses. These changes in mineral bone composition may have significant dosimetric implications when considering localized marrow dosimetry for radionuclides that target mineral bone in the newborn child.

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

NASA Astrophysics Data System (ADS)

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%.

An age dependent model for radium metabolism in man.

PubMed

Johnson, J R

1983-01-01

The model developed by a Task Group of Committee 2 of ICRP to describe Alkaline Earth Metabolism in Adult Man (ICRP Publication 20) has been modified so that recycling is handled explicitly, and retention in mineral bone is represented by second compartments rather than by the product of a power function and an exponential. This model has been extended to include all ages from birth to adult man, and has been coupled with modified "ICRP" lung and G.I. tract models so that activity in organs can be calculated as functions of time during or after exposures. These activities, and age dependent "specific effective energy" factors, are then used to calculate age dependent dose rates, and dose commitments. This presentation describes this work, with emphasis on the model parameters and results obtained for radium.

All about MAX: a male adult voxel phantom for Monte Carlo calculations in radiation protection dosimetry

NASA Astrophysics Data System (ADS)

Kramer, R.; Vieira, J. W.; Khoury, H. J.; Lima, F. R. A.; Fuelle, D.

2003-05-01

The MAX (Male Adult voXel) phantom has been developed from existing segmented images of a male adult body, in order to achieve a representation as close as possible to the anatomical properties of the reference adult male specified by the ICRP. The study describes the adjustments of the soft-tissue organ masses, a new dosimetric model for the skin, a new model for skeletal dosimetry and a computational exposure model based on coupling the MAX phantom with the EGS4 Monte Carlo code. Conversion coefficients between equivalent dose to the red bone marrow as well as effective MAX dose and air-kerma free in air for external photon irradiation from the front and from the back, respectively, are presented and compared with similar data from other human phantoms.

All about FAX: a Female Adult voXel phantom for Monte Carlo calculation in radiation protection dosimetry.

PubMed

Kramer, R; Khoury, H J; Vieira, J W; Loureiro, E C M; Lima, V J M; Lima, F R A; Hoff, G

2004-12-07

The International Commission on Radiological Protection (ICRP) has created a task group on dose calculations, which, among other objectives, should replace the currently used mathematical MIRD phantoms by voxel phantoms. Voxel phantoms are based on digital images recorded from scanning of real persons by computed tomography or magnetic resonance imaging (MRI). Compared to the mathematical MIRD phantoms, voxel phantoms are true to the natural representations of a human body. Connected to a radiation transport code, voxel phantoms serve as virtual humans for which equivalent dose to organs and tissues from exposure to ionizing radiation can be calculated. The principal database for the construction of the FAX (Female Adult voXel) phantom consisted of 151 CT images recorded from scanning of trunk and head of a female patient, whose body weight and height were close to the corresponding data recommended by the ICRP in Publication 89. All 22 organs and tissues at risk, except for the red bone marrow and the osteogenic cells on the endosteal surface of bone ('bone surface'), have been segmented manually with a technique recently developed at the Departamento de Energia Nuclear of the UFPE in Recife, Brazil. After segmentation the volumes of the organs and tissues have been adjusted to agree with the organ and tissue masses recommended by ICRP for the Reference Adult Female in Publication 89. Comparisons have been made with the organ and tissue masses of the mathematical EVA phantom, as well as with the corresponding data for other female voxel phantoms. The three-dimensional matrix of the segmented images has eventually been connected to the EGS4 Monte Carlo code. Effective dose conversion coefficients have been calculated for exposures to photons, and compared to data determined for the mathematical MIRD-type phantoms, as well as for other voxel phantoms.

Development of the two Korean adult tomographic computational phantoms for organ dosimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Choonsik; Lee, Choonik; Park, Sang-Hyun

2006-02-15

Following the previously developed Korean tomographic phantom, KORMAN, two additional whole-body tomographic phantoms of Korean adult males were developed from magnetic resonance (MR) and computed tomography (CT) images, respectively. Two healthy male volunteers, whose body dimensions were fairly representative of the average Korean adult male, were recruited and scanned for phantom development. Contiguous whole body MR images were obtained from one subject exclusive of the arms, while whole-body CT images were acquired from the second individual. A total of 29 organs and tissues and 19 skeletal sites were segmented via image manipulation techniques such as gray-level thresholding, region growing, andmore » manual drawing, in which each of segmented image slice was subsequently reviewed by an experienced radiologist for anatomical accuracy. The resulting phantoms, the MR-based KTMAN-1 (Korean Typical MAN-1) and the CT-based KTMAN-2 (Korean Typical MAN-2), consist of 300x150x344 voxels with a voxel resolution of 2x2x5 mm{sup 3} for both phantoms. Masses of segmented organs and tissues were calculated as the product of a nominal reference density, the prevoxel volume, and the cumulative number of voxels defining each organs or tissue. These organs masses were then compared with those of both the Asian and the ICRP reference adult male. Organ masses within both KTMAN-1 and KTMAN-2 showed differences within 40% of Asian and ICRP reference values, with the exception of the skin, gall bladder, and pancreas which displayed larger differences. The resulting three-dimensional binary file was ported to the Monte Carlo code MCNPX2.4 to calculate organ doses following external irradiation for illustrative purposes. Colon, lung, liver, and stomach absorbed doses, as well as the effective dose, for idealized photon irradiation geometries (anterior-posterior and right lateral) were determined, and then compared with data from two other tomographic phantoms (Asian and Caucasian), and stylized ORNL phantom. The armless KTMAN-1 can be applied to dosimetry for computed tomography or lateral x-ray examination, while the whole body KTMAN-2 can be used for radiation protection dosimetry.« less

Deformable adult human phantoms for radiation protection dosimetry: anthropometric data representing size distributions of adult worker populations and software algorithms

NASA Astrophysics Data System (ADS)

Hum Na, Yong; Zhang, Binquan; Zhang, Juying; Caracappa, Peter F.; Xu, X. George

2010-07-01

Computational phantoms representing workers and patients are essential in estimating organ doses from various occupational radiation exposures and medical procedures. Nearly all existing phantoms, however, were purposely designed to match internal and external anatomical features of the Reference Man as defined by the International Commission on Radiological Protection (ICRP). To reduce uncertainty in dose calculations caused by anatomical variations, a new generation of phantoms of varying organ and body sizes is needed. This paper presents detailed anatomical data in tables and graphs that are used to design such size-adjustable phantoms representing a range of adult individuals in terms of the body height, body weight and internal organ volume/mass. Two different sets of information are used to derive the phantom sets: (1) individual internal organ size and volume/mass distribution data derived from the recommendations of the ICRP in Publications 23 and 89 and (2) whole-body height and weight percentile data from the National Health and Nutrition Examination Survey (NHANES 1999-2002). The NHANES height and weight data for 19 year old males and females are used to estimate the distributions of individuals' size, which is unknown, that corresponds to the ICRP organ and tissue distributions. This paper then demonstrates the usage of these anthropometric data in the development of deformable anatomical phantoms. A pair of phantoms—modeled entirely in mesh surfaces—of the adult male and female, RPI-adult male (AM) and RPI-adult female (AF) are used as the base for size-adjustable phantoms. To create percentile-specific phantoms from these two base phantoms, organ surface boundaries are carefully altered according to the tabulated anthropometric data. Software algorithms are developed to automatically match the organ volumes and masses with desired values. Finally, these mesh-based, percentile-specific phantoms are converted into voxel-based phantoms for Monte Carlo radiation transport simulations. This paper also compares absorbed organ doses for the RPI-AM-5th-height and -weight percentile phantom (165 cm in height and 56 kg in weight) and the RPI-AM-95th-height and -weight percentile phantom (188 cm in height and 110 kg in weight) with those for the RPI-AM-50th-height and -weight percentile phantom (176 cm in height and 73 kg in weight) from exposures to 0.5 MeV external photon beams. The results suggest a general finding that the phantoms representing a slimmer and shorter individual male received higher absorbed organ doses because of lesser degree of photon attenuation due to smaller amount of body fat. In particular, doses to the prostate and adrenal in the RPI-AM-5th-height and -weight percentile phantom is about 10% greater than those in the RPI-AM-50th-height and -weight percentile phantom approximating the ICRP Reference Man. On the other hand, the doses to the prostate and adrenal in the RPI-AM-95th-height and -weight percentile phantom are approximately 20% greater than those in the RPI-AM-50th-height and -weight percentile phantom. Although this study only considered the photon radiation of limited energies and irradiation geometries, the potential to improve the organ dose accuracy using the deformable phantom technology is clearly demonstrated.

Deformable adult human phantoms for radiation protection dosimetry: anthropometric data representing size distributions of adult worker populations and software algorithms

PubMed Central

Na, Yong Hum; Zhang, Binquan; Zhang, Juying; Caracappa, Peter F; Xu, X George

2012-01-01

Computational phantoms representing workers and patients are essential in estimating organ doses from various occupational radiation exposures and medical procedures. Nearly all existing phantoms, however, were purposely designed to match internal and external anatomical features of the Reference Man as defined by the International Commission on Radiological Protection (ICRP). To reduce uncertainty in dose calculations caused by anatomical variations, a new generation of phantoms of varying organ and body sizes is needed. This paper presents detailed anatomical data in tables and graphs that are used to design such size-adjustable phantoms representing a range of adult individuals in terms of the body height, body weight and internal organ volume/mass. Two different sets of information are used to derive the phantom sets: (1) individual internal organ size and volume/mass distribution data derived from the recommendations of the ICRP in Publications 23 and 89 and (2) whole-body height and weight percentile data from the National Health and Nutrition Examination Survey (NHANES 1999–2002). The NHANES height and weight data for 19 year old males and females are used to estimate the distributions of individuals’ size, which is unknown, that corresponds to the ICRP organ and tissue distributions. This paper then demonstrates the usage of these anthropometric data in the development of deformable anatomical phantoms. A pair of phantoms—modeled entirely in mesh surfaces—of the adult male and female, RPI-adult male (AM) and RPI-adult female (AF) are used as the base for size-adjustable phantoms. To create percentile-specific phantoms from these two base phantoms, organ surface boundaries are carefully altered according to the tabulated anthropometric data. Software algorithms are developed to automatically match the organ volumes and masses with desired values. Finally, these mesh-based, percentile-specific phantoms are converted into voxel-based phantoms for Monte Carlo radiation transport simulations. This paper also compares absorbed organ doses for the RPI-AM-5th-height and -weight percentile phantom (165 cm in height and 56 kg in weight) and the RPI-AM-95th-height and -weight percentile phantom (188 cm in height and 110 kg in weight)with those for theRPI-AM-50th-height and -weight percentile phantom (176 cm in height and 73 kg in weight) from exposures to 0.5 MeV external photon beams. The results suggest a general finding that the phantoms representing a slimmer and shorter individual male received higher absorbed organ doses because of lesser degree of photon attenuation due to smaller amount of body fat. In particular, doses to the prostate and adrenal in the RPI-AM-5th-height and -weight percentile phantom is about 10% greater than those in the RPI-AM-50th-height and -weight percentile phantom approximating the ICRP Reference Man. On the other hand, the doses to the prostate and adrenal in the RPI-AM-95th-height and -weight percentile phantom are approximately 20% greater than those in the RPI-AM-50th-height and -weight percentile phantom. Although this study only considered the photon radiation of limited energies and irradiation geometries, the potential to improve the organ dose accuracy using the deformable phantom technology is clearly demonstrated. PMID:20551505

Comparison of fluence-to-dose conversion coefficients for deuterons, tritons and helions.

PubMed

Copeland, Kyle; Friedberg, Wallace; Sato, Tatsuhiko; Niita, Koji

2012-02-01

Secondary radiation in aircraft and spacecraft includes deuterons, tritons and helions. Two sets of fluence-to-effective dose conversion coefficients for isotropic exposure to these particles were compared: one used the particle and heavy ion transport code system (PHITS) radiation transport code coupled with the International Commission on Radiological Protection (ICRP) reference phantoms (PHITS-ICRP) and the other the Monte Carlo N-Particle eXtended (MCNPX) radiation transport code coupled with modified BodyBuilder™ phantoms (MCNPX-BB). Also, two sets of fluence-to-effective dose equivalent conversion coefficients calculated using the PHITS-ICRP combination were compared: one used quality factors based on linear energy transfer; the other used quality factors based on lineal energy (y). Finally, PHITS-ICRP effective dose coefficients were compared with PHITS-ICRP effective dose equivalent coefficients. The PHITS-ICRP and MCNPX-BB effective dose coefficients were similar, except at high energies, where MCNPX-BB coefficients were higher. For helions, at most energies effective dose coefficients were much greater than effective dose equivalent coefficients. For deuterons and tritons, coefficients were similar when their radiation weighting factor was set to 2.

Organ dose calculations by Monte Carlo modeling of the updated VCH adult male phantom against idealized external proton exposure

NASA Astrophysics Data System (ADS)

Zhang, Guozhi; Liu, Qian; Zeng, Shaoqun; Luo, Qingming

2008-07-01

The voxel-based visible Chinese human (VCH) adult male phantom has offered a high-quality test bed for realistic Monte Carlo modeling in radiological dosimetry simulations. The phantom has been updated in recent effort by adding newly segmented organs, revising walled and smaller structures as well as recalibrating skeletal marrow distributions. The organ absorbed dose against external proton exposure was calculated at a voxel resolution of 2 × 2 × 2 mm3 using the MCNPX code for incident energies from 20 MeV to 10 GeV and for six idealized irradiation geometries: anterior-posterior (AP), posterior-anterior (PA), left-lateral (LLAT), right-lateral (RLAT), rotational (ROT) and isotropic (ISO), respectively. The effective dose on the VCH phantom was derived in compliance with the evaluation scheme for the reference male proposed in the 2007 recommendations of the International Commission on Radiological Protection (ICRP). Algorithm transitions from the revised radiation and tissue weighting factors are accountable for approximately 90% and 10% of effective dose discrepancies in proton dosimetry, respectively. Results are tabulated in terms of fluence-to-dose conversion coefficients for practical use and are compared with data from other models available in the literature. Anatomical variations between various computational phantoms lead to dose discrepancies ranging from a negligible level to 100% or more at proton energies below 200 MeV, corresponding to the spatial geometric locations of individual organs within the body. Doses show better agreement at higher energies and the deviations are mostly within 20%, to which the organ volume and mass differences should be of primary responsibility. The impact of body size on dose distributions was assessed by dosimetry of a scaled-up VCH phantom that was resized in accordance with the height and total mass of the ICRP reference man. The organ dose decreases with the directionally uniform enlargement of voxels. Potential pathways to improve the VCH phantom have also been briefly addressed. This work pertains to VCH-based systematic multi-particle dose investigations and will contribute to comparative dosimetry studies of ICRP standardized voxel phantoms in the near future.

Use of the ICRP system for the protection of marine ecosystems.

PubMed

Telleria, D; Cabianca, T; Proehl, G; Kliaus, V; Brown, J; Bossio, C; Van der Wolf, J; Bonchuk, I; Nilsen, M

2015-06-01

The International Commission on Radiological Protection (ICRP) recently reinforced the international system of radiological protection, initially focused on humans, by identifying principles of environmental protection and proposing a framework for assessing impacts of ionising radiation on non-human species, based on a reference flora and fauna approach. For this purpose, ICRP developed dosimetric models for a set of Reference Animals and Plants, which are representative of flora and fauna in different environments (terrestrial, freshwater, marine), and produced criteria based on information on radiation effects, with the aim of evaluating the level of potential or actual radiological impacts, and as an input for decision making. The approach developed by ICRP for flora and fauna is consistent with the approach used to protect humans. The International Atomic Energy Agency (IAEA) includes considerations on the protection of the environment in its safety standards, and is currently developing guidelines to assess radiological impacts based on the aforementioned ICRP approach. This paper presents the method developed by IAEA, in a series of meetings with international experts, to enable assessment of the radiological impact to the marine environment in connection with the Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter 1972 (London Convention 1972). This method is based on IAEA's safety standards and ICRP's recommendations, and was presented in 2013 for consideration by representatives of the contracting parties of the London Convention 1972; it was approved for inclusion in its procedures, and is in the process of being incorporated into guidelines. © The International Society for Prosthetics and Orthotics Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

An image-based skeletal model for the ICRP reference adult male—specific absorbed fractions for neutron-generated recoil protons

NASA Astrophysics Data System (ADS)

Jokisch, D. W.; Rajon, D. A.; Bahadori, A. A.; Bolch, W. E.

2011-11-01

Recoiling hydrogen nuclei are a principle mechanism for energy deposition from incident neutrons. For neutrons incident on the human skeleton, the small sizes of two contrasting media (trabecular bone and marrow) present unique problems due to a lack of charged-particle (protons) equilibrium. Specific absorbed fractions have been computed for protons originating in the human skeletal tissues for use in computing neutron dose response functions. The proton specific absorbed fractions were computed using a pathlength-based range-energy calculation in trabecular skeletal samples of a 40 year old male cadaver.

A set of 4D pediatric XCAT reference phantoms for multimodality research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Norris, Hannah, E-mail: Hannah.norris@duke.edu; Zhang, Yakun; Bond, Jason

Purpose: The authors previously developed an adult population of 4D extended cardiac-torso (XCAT) phantoms for multimodality imaging research. In this work, the authors develop a reference set of 4D pediatric XCAT phantoms consisting of male and female anatomies at ages of newborn, 1, 5, 10, and 15 years. These models will serve as the foundation from which the authors will create a vast population of pediatric phantoms for optimizing pediatric CT imaging protocols. Methods: Each phantom was based on a unique set of CT data from a normal patient obtained from the Duke University database. The datasets were selected tomore » best match the reference values for height and weight for the different ages and genders according to ICRP Publication 89. The major organs and structures were segmented from the CT data and used to create an initial pediatric model defined using nonuniform rational B-spline surfaces. The CT data covered the entire torso and part of the head. To complete the body, the authors manually added on the top of the head and the arms and legs using scaled versions of the XCAT adult models or additional models created from cadaver data. A multichannel large deformation diffeomorphic metric mapping algorithm was then used to calculate the transform from a template XCAT phantom (male or female 50th percentile adult) to the target pediatric model. The transform was applied to the template XCAT to fill in any unsegmented structures within the target phantom and to implement the 4D cardiac and respiratory models in the new anatomy. The masses of the organs in each phantom were matched to the reference values given in ICRP Publication 89. The new reference models were checked for anatomical accuracy via visual inspection. Results: The authors created a set of ten pediatric reference phantoms that have the same level of detail and functionality as the original XCAT phantom adults. Each consists of thousands of anatomical structures and includes parameterized models for the cardiac and respiratory motions. Based on patient data, the phantoms capture the anatomic variations of childhood, such as the development of bone in the skull, pelvis, and long bones, and the growth of the vertebrae and organs. The phantoms can be combined with existing simulation packages to generate realistic pediatric imaging data from different modalities. Conclusions: The development of patient-derived pediatric computational phantoms is useful in providing variable anatomies for simulation. Future work will expand this ten-phantom base to a host of pediatric phantoms representative of the public at large. This can provide a means to evaluate and improve pediatric imaging devices and to optimize CT protocols in terms of image quality and radiation dose.« less

Comparison of internal dosimetry factors for three classes of adult computational phantoms with emphasis on I-131 in the thyroid

NASA Astrophysics Data System (ADS)

Lamart, Stephanie; Bouville, Andre; Simon, Steven L.; Eckerman, Keith F.; Melo, Dunstana; Lee, Choonsik

2011-11-01

The S values for 11 major target organs for I-131 in the thyroid were compared for three classes of adult computational human phantoms: stylized, voxel and hybrid phantoms. In addition, we compared specific absorbed fractions (SAFs) with the thyroid as a source region over a broader photon energy range than the x- and gamma-rays of I-131. The S and SAF values were calculated for the International Commission on Radiological Protection (ICRP) reference voxel phantoms and the University of Florida (UF) hybrid phantoms by using the Monte Carlo transport method, while the S and SAF values for the Oak Ridge National Laboratory (ORNL) stylized phantoms were obtained from earlier publications. Phantoms in our calculations were for adults of both genders. The 11 target organs and tissues that were selected for the comparison of S values are brain, breast, stomach wall, small intestine wall, colon wall, heart wall, pancreas, salivary glands, thyroid, lungs and active marrow for I-131 and thyroid as a source region. The comparisons showed, in general, an underestimation of S values reported for the stylized phantoms compared to the values based on the ICRP voxel and UF hybrid phantoms and relatively good agreement between the S values obtained for the ICRP and UF phantoms. Substantial differences were observed for some organs between the three types of phantoms. For example, the small intestine wall of ICRP male phantom and heart wall of ICRP female phantom showed up to eightfold and fourfold greater S values, respectively, compared to the reported values for the ORNL phantoms. UF male and female phantoms also showed significant differences compared to the ORNL phantom, 4.0-fold greater for the small intestine wall and 3.3-fold greater for the heart wall. In our method, we directly calculated the S values without using the SAFs as commonly done. Hence, we sought to confirm the differences observed in our S values by comparing the SAFs among the phantoms with the thyroid as a source region for selected target organs—small intestine wall, lungs, pancreas and breast—as well as illustrate differences in energy deposition across the energy range (12 photon energies from 0.01 to 4 MeV). Differences were found in the SAFs between phantoms in a similar manner as the differences observed in S values but with larger differences at lower photon energies. To investigate the differences observed in the S and SAF values, the chord length distributions (CLDs) were computed for the selected source-target pairs and compared across the phantoms. As demonstrated by the CLDs, we found that the differences between phantoms in those factors used in internal dosimetry were governed to a significant degree by inter-organ distances which are a function of organ shape as well as organ location.

WE-E-BRE-01: An Image-Based Skeletal Dosimetry Model for the ICRP Reference Adult Female - Internal Electron Sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

O'Reilly, S; Maynard, M; Marshall, E

Purpose: Limitations seen in previous skeletal dosimetry models, which are still employed in commonly used software today, include the lack of consideration of electron escape and cross-fire from cortical bone, the modeling of infinite spongiosa, the disregard of the effect of varying cellularity on active marrow self-irradiation, and the lack of use of the more recent ICRP definition of a 50 micron surrogate tissue region for the osteoprogenitor cells - shallow marrow. These limitations were addressed in the present dosimetry model. Methods: Electron transport was completed to determine specific absorbed fractions to active marrow and shallow marrow of the skeletalmore » regions of the adult female. The bone macrostructure was obtained from the whole-body hybrid computational phantom of the UF series of reference phantoms, while the bone microstructure was derived from microCT images of skeletal region samples taken from a 45 year-old female cadaver. The target tissue regions were active marrow and shallow marrow. The source tissues were active marrow, inactive marrow, trabecular bone volume, trabecular bone surfaces, cortical bone volume and cortical bone surfaces. The marrow cellularity was varied from 10 to 100 percent for active marrow self-irradiation. A total of 33 discrete electron energies, ranging from 1 keV to 10 MeV, were either simulated or modeled analytically. Results: The method of combining macro- and microstructure absorbed fractions calculated using MCNPX electron transport was found to yield results similar to those determined with the PIRT model for the UF adult male in the Hough et al. study. Conclusion: The calculated skeletal averaged absorbed fractions for each source-target combination were found to follow similar trends of more recent dosimetry models (image-based models) and did not follow current models used in nuclear medicine dosimetry at high energies (due to that models use of an infinite expanse of trabecular spongiosa)« less

Basis for standards: ICRP activities.

PubMed

Vano, E

2015-07-01

The purpose of this chapter is to describe work achieved recently by the International Commission on Radiological Protection (ICRP) and especially by Committee 3 (Protection in Medicine) and its use for standards. In March 1960, the Board of Governors of the International Atomic Energy Agency approved the Agency's 'Health and Safety Measures', stating that the Agency's 'Basic Safety Standards' (BSS) would be based, to the extent possible, on the recommendations of the ICRP. In a similar way, the Council of the European Union took into account the new recommendations of the ICRP when adopting the new Directive 2013/59/EURATOM that laid down BSS for protection against the dangers arising from exposure to ionising radiation. The new limit for the lens of the eyes for occupational exposures has been incorporated into these international standards and several articles dealing with medical exposures: justification, optimisation, recording patient doses, the use of diagnostic reference levels, training, accidental and unintended exposures, etc. have also been included in agreement with the ICRP recommendations. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

An image-based skeletal dosimetry model for the ICRP reference adult male—internal electron sources

NASA Astrophysics Data System (ADS)

Hough, Matthew; Johnson, Perry; Rajon, Didier; Jokisch, Derek; Lee, Choonsik; Bolch, Wesley

2011-04-01

In this study, a comprehensive electron dosimetry model of the adult male skeletal tissues is presented. The model is constructed using the University of Florida adult male hybrid phantom of Lee et al (2010 Phys. Med. Biol. 55 339-63) and the EGSnrc-based Paired Image Radiation Transport code of Shah et al (2005 J. Nucl. Med. 46 344-53). Target tissues include the active bone marrow, associated with radiogenic leukemia, and total shallow marrow, associated with radiogenic bone cancer. Monoenergetic electron emissions are considered over the energy range 1 keV to 10 MeV for the following sources: bone marrow (active and inactive), trabecular bone (surfaces and volumes), and cortical bone (surfaces and volumes). Specific absorbed fractions are computed according to the MIRD schema, and are given as skeletal-averaged values in the paper with site-specific values reported in both tabular and graphical format in an electronic annex available from http://stacks.iop.org/0031-9155/56/2309/mmedia. The distribution of cortical bone and spongiosa at the macroscopic dimensions of the phantom, as well as the distribution of trabecular bone and marrow tissues at the microscopic dimensions of the phantom, is imposed through detailed analyses of whole-body ex vivo CT images (1 mm resolution) and spongiosa-specific ex vivo microCT images (30 µm resolution), respectively, taken from a 40 year male cadaver. The method utilized in this work includes: (1) explicit accounting for changes in marrow self-dose with variations in marrow cellularity, (2) explicit accounting for electron escape from spongiosa, (3) explicit consideration of spongiosa cross-fire from cortical bone, and (4) explicit consideration of the ICRP's change in the surrogate tissue region defining the location of the osteoprogenitor cells (from a 10 µm endosteal layer covering the trabecular and cortical surfaces to a 50 µm shallow marrow layer covering trabecular and medullary cavity surfaces). Skeletal-averaged values of absorbed fraction in the present model are noted to be very compatible with those weighted by the skeletal tissue distributions found in the ICRP Publication 110 adult male and female voxel phantoms, but are in many cases incompatible with values used in current and widely implemented internal dosimetry software.

Construction of new skin models and calculation of skin dose coefficients for electron exposures

NASA Astrophysics Data System (ADS)

Yeom, Yeon Soo; Kim, Chan Hyeong; Nguyen, Thang Tat; Choi, Chansoo; Han, Min Cheol; Jeong, Jong Hwi

2016-08-01

The voxel-type reference phantoms of the International Commission on Radiological Protection (ICRP), due to their limited voxel resolutions, cannot represent the 50- μm-thick radiosensitive target layer of the skin necessary for skin dose calculations. Alternatively, in ICRP Publication 116, the dose coefficients (DCs) for the skin were calculated approximately, averaging absorbed dose over the entire skin depth of the ICRP phantoms. This approximation is valid for highly-penetrating radiations such as photons and neutrons, but not for weakly penetrating radiations like electrons due to the high gradient in the dose distribution in the skin. To address the limitation, the present study introduces skin polygon-mesh (PM) models, which have been produced by converting the skin models of the ICRP voxel phantoms to a high-quality PM format and adding a 50- μm-thick radiosensitive target layer into the skin models. Then, the constructed skin PM models were implemented in the Geant4 Monte Carlo code to calculate the skin DCs for external exposures of electrons. The calculated values were then compared with the skin DCs of the ICRP Publication 116. The results of the present study show that for high-energy electrons (≥ 1 MeV), the ICRP-116 skin DCs are, indeed, in good agreement with the skin DCs calculated in the present study. For low-energy electrons (< 1 MeV), however, significant discrepancies were observed, and the ICRP-116 skin DCs underestimated the skin dose as much as 15 times for some energies. Besides, regardless of the small tissue weighting factor of the skin ( w T = 0.01), the discrepancies in the skin dose were found to result in significant discrepancies in the effective dose, demonstarting that the effective DCs in ICRP-116 are not reliable for external exposure to electrons.

Particle deposition and clearance of atmospheric particles in the human respiratory tract during LACE 98

NASA Astrophysics Data System (ADS)

Bundke, U.; Hänel, G.

2003-04-01

During the LACE 98footnote{Lindenberg Aerosol Characterization Experiment, (Germany) 1998} experiment microphysical, chemical and optical properties of atmospheric particles were measured by several groups. (Bundke et al.). The particle deposition and clearance of the particles in the human respiratory tract was calculated using the ICRP (International Commission on Radiological Protection) deposition and clearance model (ICRP 1994). Particle growth as function of relative humidity outside the body was calculated from measurement data using the model introduced by Bundke et al.. Particle growth inside the body was added using a non-equilibrium particle growth model. As a result of the calculations, time series of the total dry particle mass and -size distribution were obtained for all compartments of the human respiratory tract defined by ICRP 1994. The combined ICRP deposition and clearance model was initialized for different probationers like man, woman, children of different ages and several circumstances like light work, sitting, sleeping etc. Keeping the conditions observed during LACE 98 constant a approximation of the aerosol burdens of the different compartments was calculated up to 4 years of exposure and compared to the results from Snipes et al. for the "Phoenix" and "Philadelphia" aerosol. References: footnotesize{ Bundke, U. et al.,it{Aerosol Optical Properties during the Lindenberg Aerosol Characterization Experiment (LACE 98)} ,10.1029/2000JD000188, JGR, 2002 ICRP,it{Human Respiratory Tract Model for Radiological Protection, Bd. ICRP Publication 66}, Annals of the ICRP, 24,1-3, Elsevier Science, Ocford, 1994 Snipes et al. ,it{The 1994 ICRP66 Human Respiratory Tract Model as a Tool for predicting Lung Burdens from Exposure to Environmental Aerosols}, Appl. Occup. Environ. Hyg., 12, 547-553,1997}

Radiation safety concerns for pregnant or breast feeding patients. The positions of the NCRP and the ICRP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meinhold, C.B.

For many years, protecting the fetus has been a concern of the National Council on Radiation Protection and Measurements (NCRP) and the International Commission on Radiological Protection (ICRP). Early recommendations focused on the possibility of a wide variety of detrimental developmental effects while later recommendations focused on the potential for severe mental retardation and/or reduction in the intelligence quotient (I.Q.). The latest recommendations also note that the risk of cancer for the fetus is probably two to three times greater per Sv than in the adult. For all these reasons, the NCRP and the ICRP have provided guidance to physiciansmore » on taking all reasonable steps to ascertain whether any woman requiring a radiological or nuclear medicine procedure is pregnant or nursing a child. The NCRP and the ICRP also advise the clinician to postpone such procedures until after delivery or cessation of nursing, if possible.« less

Dose conversion factors for radon: recent developments.

PubMed

Marsh, James W; Harrison, John D; Laurier, Dominique; Blanchardon, Eric; Paquet, François; Tirmarche, Margot

2010-10-01

Epidemiological studies of the occupational exposure of miners and domestic exposures of the public have provided strong and complementary evidence of the risks of lung cancer following inhalation of radon progeny. Recent miner epidemiological studies, which include low levels of exposure, long duration of follow-up, and good quality of individual exposure data, suggest higher risks of lung cancer per unit exposure than assumed previously by the International Commission on Radiological Protection (ICRP). Although risks can be managed by controlling exposures, dose estimates are required for the control of occupational exposures and are also useful for comparing sources of public exposure. Currently, ICRP calculates doses from radon and its progeny using dose conversion factors from exposure (WLM) to dose (mSv) based on miner epidemiological studies, referred to as the epidemiological approach. Revision of these dose conversion factors using risk estimates based on the most recent epidemiological data gives values that are in good agreement with the results of calculations using ICRP biokinetic and dosimetric models, the dosimetric approach. ICRP now proposes to treat radon progeny in the same way as other radionuclides and to publish dose coefficients calculated using models, for use within the ICRP system of protection.

Current knowledge on radon risk: implications for practical radiation protection? radon workshop, 1/2 December 2015, Bonn, BMUB (Bundesministerium für Umwelt, Naturschutz, Bau und Reaktorsicherheit; Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety).

PubMed

Müller, Wolfgang-Ulrich; Giussani, Augusto; Rühm, Werner; Lecomte, Jean-Francois; Harrison, John; Kreuzer, Michaela; Sobotzki, Christina; Breckow, Joachim

2016-08-01

ICRP suggested a strategy based on the distinction between a protection approach for dwellings and one for workplaces in the previous recommendations on radon. Now, the Commission recommends an integrated approach for the protection against radon exposure in all buildings irrespective of their purpose and the status of their occupants. The strategy of protection in buildings, implemented through a national action plan, is based on the application of the optimisation principle below a derived reference level in concentration (maximum 300 Bq m(-3)). A problem, however, arises that due to new epidemiological findings and application of dosimetric models, ICRP 115 (Ann ICRP 40, 2010) presents nominal probability coefficients for radon exposure that are approximately by a factor of 2 larger than in the former recommendations of ICRP 65 (Ann ICRP 23, 1993). On the basis of the so-called epidemiological approach and the dosimetric approach, the doubling of risk per unit exposure is represented by a doubling of the dose coefficients, while the risk coefficient of ICRP 103 (2007) remains unchanged. Thus, an identical given radon exposure situation with the new dose coefficients would result in a doubling of dose compared with the former values. This is of serious conceptual implications. A possible solution of this problem was presented during the workshop.

Radiological Protection in Space: Indication from the ICRP Task Group

NASA Astrophysics Data System (ADS)

Dietze, Günther

In 2007 the International Commission on Radiological Protection (ICRP) has established a Task Group (Radiation Protection in Space) dealing with the problems of radiation protection of astronauts in space missions. Its first task is a report on "Assessment of Radiation Exposure of Astronauts in Space". When the ICRP published its general recommendations for radiological protection in 2007 (ICRP Publication 103 following ICRP Publication 60 (1991)) it was obvious that these recommendations do not really consider the special situation of astronauts in space. The radiation field with its high content of charged particles of very high energies strongly differs from usual radiation fields on ground. For example, this has consequences for the assessment of doses in the body of astronauts. The ICRP Task Group has discussed this situation and the presentation will deal with some consequences for the concept of radiation dosimetry and radiological protection in space. This includes e. g. the assessment of organ doses and the application of the effective dose concept with its definition of radiation weighting factors. Radiation quality of high energy heavy ions may be defined different than usually performed on ground. An approach of using the quality factor concept in the definition of an "effective dose" is favored for application in space missions similar to the method proposed in NCRP Report 142. New data calculated on the basis of the reference anthropomorphic voxel phantoms recommended by ICRP support this procedure. Individual dosimetry is a further subject of discussion in the Task Group. While the operational dose equivalent quantities generally in use in radiation protection on ground are not helpful for applications in space, different procedures of the assessment of organ and effective doses are applied. The Task Group is dealing with this situation.

SU-E-J-93: Development of Pre-Contoured Human Model Library in DICOM-RT Format for the Epidemiological Study of the Radiotherapy Patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pyakuryal, A; Lee, C; Lee, C

Purpose: Prior to 3D conformal radiation therapy planning, patient anatomy information was mostly limited to 2D beams-eye-view from the conventional simulator. To analyze the outcomes of such treatments for radiation late effects, 3D computational human models are often used in commercial treatment planning systems (TPSs). However, several underlying difficulties such as time-consuming manual delineation procedures of a large number of structures in the model have always limited its applications. Primary objective of this work was to develop a human model library for the epidemiological study by converting 3D-surface model organs to DICOM-RT format (DICOM-RT structure) using an in-house built software.more » We converted the ICRP reference human models to DICOM-RT models, which can be readily adopted for various dose calculations. Methods: MATLAB based code were utilized to convert the contour drawings extracted in text-format from the 3D graphic-tool, Rhinoceros into DICOM-RT structure format for 50 different organs of each model using a 16GB dual-core processor. The conversion periods were measured for each DICOM-RT models, and the reconstructed structure volumes were validated against the original 3D-surface models in the TPS. Ten reference hybrid whole-body models (8-pediatric and 2-adults) were automatically processed to create DICOM-RT computational human model library. Results: Mean contour conversion period was found to be 580 (N=2) and 394.5 (N=8) seconds for 50 organs in the adult and pediatric models respectively. A good agreement for large organs (NRMSD <1.0%) and small organs (NRMSD <7.7%) was also observed between the original volumes and corresponding DICOM-RT structure volumes of the organs. Conclusion: The ICRP reference human models were converted into DICOM-RT format to support the epidemiological study using a large cohort of conventional radiotherapy patients. Due to its DICOM-compatibility, the library may be implemented to many other different applications. We also expect to develop the library by including additional models in future.« less

Korean anatomical reference data for adults for use in radiological protection

NASA Astrophysics Data System (ADS)

Choi, Chansoo; Yeom, Yeon Soo; Nguyen, Thang Tat; Lee, Hanjin; Han, Haegin; Shin, Bangho; Zhang, Xujia; Kim, Chan Hyeong; Chung, Beom Sun

2018-01-01

For radiological protection from exposure to ionizing radiation, in which a population-averaged dose evaluation is used, establishing a system of reference anatomical and physiological data for a specific population of interest is important. Some studies were done in the past to establish Korean reference data; however, the data provided the mass values only for a limited number of organs/tissues. In addition, the standing height and total body mass are based on 20-year-old data. In the present study, a new set of Korean reference anatomical values was established for use in the radiological protection of Korean workers and members of the public. The established Korean reference data provide the masses of 58 organs/tissues, including those needed to calculate the effective dose, which were derived by collecting and analyzing various scientific reports in the literature and data. In addition, the data provide not only standing height and total body mass, but also 131 additional anthropometric parameters; these values were derived from the most recent Korean national survey project, 7 th Size Korea. The characteristics of the data were also compared with several other population data, including the Asian and the International Commission on Radiological Protection (ICRP) reference data.

SimDoseCT: dose reporting software based on Monte Carlo simulation for a 320 detector-row cone-beam CT scanner and ICRP computational adult phantoms

NASA Astrophysics Data System (ADS)

Cros, Maria; Joemai, Raoul M. S.; Geleijns, Jacob; Molina, Diego; Salvadó, Marçal

2017-08-01

This study aims to develop and test software for assessing and reporting doses for standard patients undergoing computed tomography (CT) examinations in a 320 detector-row cone-beam scanner. The software, called SimDoseCT, is based on the Monte Carlo (MC) simulation code, which was developed to calculate organ doses and effective doses in ICRP anthropomorphic adult reference computational phantoms for acquisitions with the Aquilion ONE CT scanner (Toshiba). MC simulation was validated by comparing CTDI measurements within standard CT dose phantoms with results from simulation under the same conditions. SimDoseCT consists of a graphical user interface connected to a MySQL database, which contains the look-up-tables that were generated with MC simulations for volumetric acquisitions at different scan positions along the phantom using any tube voltage, bow tie filter, focal spot and nine different beam widths. Two different methods were developed to estimate organ doses and effective doses from acquisitions using other available beam widths in the scanner. A correction factor was used to estimate doses in helical acquisitions. Hence, the user can select any available protocol in the Aquilion ONE scanner for a standard adult male or female and obtain the dose results through the software interface. Agreement within 9% between CTDI measurements and simulations allowed the validation of the MC program. Additionally, the algorithm for dose reporting in SimDoseCT was validated by comparing dose results from this tool with those obtained from MC simulations for three volumetric acquisitions (head, thorax and abdomen). The comparison was repeated using eight different collimations and also for another collimation in a helical abdomen examination. The results showed differences of 0.1 mSv or less for absolute dose in most organs and also in the effective dose calculation. The software provides a suitable tool for dose assessment in standard adult patients undergoing CT examinations in a 320 detector-row cone-beam scanner.

SimDoseCT: dose reporting software based on Monte Carlo simulation for a 320 detector-row cone-beam CT scanner and ICRP computational adult phantoms.

PubMed

Cros, Maria; Joemai, Raoul M S; Geleijns, Jacob; Molina, Diego; Salvadó, Marçal

2017-07-17

This study aims to develop and test software for assessing and reporting doses for standard patients undergoing computed tomography (CT) examinations in a 320 detector-row cone-beam scanner. The software, called SimDoseCT, is based on the Monte Carlo (MC) simulation code, which was developed to calculate organ doses and effective doses in ICRP anthropomorphic adult reference computational phantoms for acquisitions with the Aquilion ONE CT scanner (Toshiba). MC simulation was validated by comparing CTDI measurements within standard CT dose phantoms with results from simulation under the same conditions. SimDoseCT consists of a graphical user interface connected to a MySQL database, which contains the look-up-tables that were generated with MC simulations for volumetric acquisitions at different scan positions along the phantom using any tube voltage, bow tie filter, focal spot and nine different beam widths. Two different methods were developed to estimate organ doses and effective doses from acquisitions using other available beam widths in the scanner. A correction factor was used to estimate doses in helical acquisitions. Hence, the user can select any available protocol in the Aquilion ONE scanner for a standard adult male or female and obtain the dose results through the software interface. Agreement within 9% between CTDI measurements and simulations allowed the validation of the MC program. Additionally, the algorithm for dose reporting in SimDoseCT was validated by comparing dose results from this tool with those obtained from MC simulations for three volumetric acquisitions (head, thorax and abdomen). The comparison was repeated using eight different collimations and also for another collimation in a helical abdomen examination. The results showed differences of 0.1 mSv or less for absolute dose in most organs and also in the effective dose calculation. The software provides a suitable tool for dose assessment in standard adult patients undergoing CT examinations in a 320 detector-row cone-beam scanner.

ICRP Publication 137: Occupational Intakes of Radionuclides: Part 3.

PubMed

Paquet, F; Bailey, M R; Leggett, R W; Lipsztein, J; Marsh, J; Fell, T P; Smith, T; Nosske, D; Eckerman, K F; Berkovski, V; Blanchardon, E; Gregoratto, D; Harrison, J D

2017-12-01

The 2007 Recommendations of the International Commission on Radiological Protection (ICRP, 2007) introduced changes that affect the calculation of effective dose, and implied a revision of the dose coefficients for internal exposure, published previously in the Publication 30 series (ICRP, 1979, 1980, 1981, 1988) and Publication 68 (ICRP, 1994). In addition, new data are now available that support an update of the radionuclide-specific information given in Publications 54 and 78 (ICRP, 1988a, 1997b) for the design of monitoring programmes and retrospective assessment of occupational internal doses. Provision of new biokinetic models, dose coefficients, monitoring methods, and bioassay data was performed by Committee 2, Task Group 21 on Internal Dosimetry, and Task Group 4 on Dose Calculations. A new series, the Occupational Intakes of Radionuclides (OIR) series, will replace the Publication 30 series and Publications 54, 68, and 78. OIR Part 1 has been issued (ICRP, 2015), and describes the assessment of internal occupational exposure to radionuclides, biokinetic and dosimetric models, methods of individual and workplace monitoring, and general aspects of retrospective dose assessment. OIR Part 2 (ICRP, 2016), this current publication and upcoming publications in the OIR series (Parts 4 and 5) provide data on individual elements and their radioisotopes, including information on chemical forms encountered in the workplace; a list of principal radioisotopes and their physical half-lives and decay modes; the parameter values of the reference biokinetic model; and data on monitoring techniques for the radioisotopes encountered most commonly in workplaces. Reviews of data on inhalation, ingestion, and systemic biokinetics are also provided for most of the elements. Dosimetric data provided in the printed publications of the OIR series include tables of committed effective dose per intake (Sv Bq−1 intake) for inhalation and ingestion, tables of committed effective dose per content (Sv Bq−1 measurement) for inhalation, and graphs of retention and excretion data per Bq intake for inhalation. These data are provided for all absorption types and for the most common isotope(s) of each element. The electronic annex that accompanies the OIR series of publications contains a comprehensive set of committed effective and equivalent dose coefficients, committed effective dose per content functions, and reference bioassay functions. Data are provided for inhalation, ingestion, and direct input to blood. This third publication in the series provides the above data for the following elements: ruthenium (Ru), antimony (Sb), tellurium (Te), iodine (I), caesium (Cs), barium (Ba), iridium (Ir), lead (Pb), bismuth (Bi), polonium (Po), radon (Rn), radium (Ra), thorium (Th), and uranium (U).

MPC and ALI: their basis and their comparison

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kennedy, W.E. Jr.; Watson, E.C.

Radiation protection regulations in the United States have evolved from the recommendations of the International Commission on Radiological Protection (ICRP) and the National Council on Radiation Protection and Measurements (NCRP). In 1959, the ICRP issued Publication 2 which contained specific recommendations on dose rate limits, permissible body burdens, metabolic data for radionuclides, and maximum permissible concentrations (MPC) in air or water. Over the next 20 years, new information became available concerning the effects of radiation, the uptake and retention of radionuclides, and the radioactive decay schemes of parent radionuclides. To include this newer information, the ICRP issued Publication 30 inmore » 1978 to supersede Publication 2. One of the secondary limits defined in Publication 30 is the annual limit of intake (ALI). Radionuclide specific ALI values are intended to replace MPC values in determining whether or not ambient air and water concentrations are sufficiently low to maintain the dose to workers within accepted dose rate limits. In this paper, we discuss the derivation of MPC and ALI values, compare inhalation committed dose equivalent factors derived from ICRP Publications 2 and 30, and discuss the practical implications of using either MPC or ALI in determining compliance with occupational exposure limits. 6 references.« less

Effective dose evaluation of NORM-added consumer products using Monte Carlo simulations and the ICRP computational human phantoms.

PubMed

Lee, Hyun Cheol; Yoo, Do Hyeon; Testa, Mauro; Shin, Wook-Geun; Choi, Hyun Joon; Ha, Wi-Ho; Yoo, Jaeryong; Yoon, Seokwon; Min, Chul Hee

2016-04-01

The aim of this study is to evaluate the potential hazard of naturally occurring radioactive material (NORM) added consumer products. Using the Monte Carlo method, the radioactive products were simulated with ICRP reference phantom and the organ doses were calculated with the usage scenario. Finally, the annual effective doses were evaluated as lower than the public dose limit of 1mSv y(-1) for 44 products. It was demonstrated that NORM-added consumer products could be quantitatively assessed for the safety regulation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Internal dosimetry with the Monte Carlo code GATE: validation using the ICRP/ICRU female reference computational model

NASA Astrophysics Data System (ADS)

Villoing, Daphnée; Marcatili, Sara; Garcia, Marie-Paule; Bardiès, Manuel

2017-03-01

The purpose of this work was to validate GATE-based clinical scale absorbed dose calculations in nuclear medicine dosimetry. GATE (version 6.2) and MCNPX (version 2.7.a) were used to derive dosimetric parameters (absorbed fractions, specific absorbed fractions and S-values) for the reference female computational model proposed by the International Commission on Radiological Protection in ICRP report 110. Monoenergetic photons and electrons (from 50 keV to 2 MeV) and four isotopes currently used in nuclear medicine (fluorine-18, lutetium-177, iodine-131 and yttrium-90) were investigated. Absorbed fractions, specific absorbed fractions and S-values were generated with GATE and MCNPX for 12 regions of interest in the ICRP 110 female computational model, thereby leading to 144 source/target pair configurations. Relative differences between GATE and MCNPX obtained in specific configurations (self-irradiation or cross-irradiation) are presented. Relative differences in absorbed fractions, specific absorbed fractions or S-values are below 10%, and in most cases less than 5%. Dosimetric results generated with GATE for the 12 volumes of interest are available as supplemental data. GATE can be safely used for radiopharmaceutical dosimetry at the clinical scale. This makes GATE a viable option for Monte Carlo modelling of both imaging and absorbed dose in nuclear medicine.

Examples of Mesh and NURBS modelling for in vivo lung counting studies.

PubMed

Farah, Jad; Broggio, David; Franck, Didier

2011-03-01

Realistic calibration coefficients for in vivo counting installations are assessed using voxel phantoms and Monte Carlo calculations. However, voxel phantoms construction is time consuming and their flexibility extremely limited. This paper involves Mesh and non-uniform rational B-splines graphical formats, of greater flexibility, to optimise the calibration of in vivo counting installations. Two studies validating the use of such phantoms and involving geometry deformation and modelling were carried out to study the morphologic effect on lung counting efficiency. The created 3D models fitted with the reference ones, with volumetric differences of <5 %. Moreover, it was found that counting efficiency varies with the inverse of lungs' volume and that the latter primes when compared with chest wall thickness. Finally, a series of different thoracic female phantoms of various cup sizes, chest girths and internal organs' volumes were created starting from the International Commission on Radiological Protection (ICRP) adult female reference computational phantom to give correction factors for the lung monitoring of female workers.

Perfusion CT of the Brain and Liver and of Lung Tumors: Use of Monte Carlo Simulation for Patient Dose Estimation for Examinations With a Cone-Beam 320-MDCT Scanner.

PubMed

Cros, Maria; Geleijns, Jacob; Joemai, Raoul M S; Salvadó, Marçal

2016-01-01

The purpose of this study was to estimate the patient dose from perfusion CT examinations of the brain, lung tumors, and the liver on a cone-beam 320-MDCT scanner using a Monte Carlo simulation and the recommendations of the International Commission on Radiological Protection (ICRP). A Monte Carlo simulation based on the Electron Gamma Shower Version 4 package code was used to calculate organ doses and the effective dose in the reference computational phantoms for an adult man and adult woman as published by the ICRP. Three perfusion CT acquisition protocols--brain, lung tumor, and liver perfusion--were evaluated. Additionally, dose assessments were performed for the skin and for the eye lens. Conversion factors were obtained to estimate effective doses and organ doses from the volume CT dose index and dose-length product. The sex-averaged effective doses were approximately 4 mSv for perfusion CT of the brain and were between 23 and 26 mSv for the perfusion CT body protocols. The eye lens dose from the brain perfusion CT examination was approximately 153 mGy. The sex-averaged peak entrance skin dose (ESD) was 255 mGy for the brain perfusion CT studies, 157 mGy for the lung tumor perfusion CT studies, and 172 mGy for the liver perfusion CT studies. The perfusion CT protocols for imaging the brain, lung tumors, and the liver performed on a 320-MDCT scanner yielded patient doses that are safely below the threshold doses for deterministic effects. The eye lens dose, peak ESD, and effective doses can be estimated for other clinical perfusion CT examinations from the conversion factors that were derived in this study.

4D XCAT phantom for multimodality imaging research

PubMed Central

Segars, W. P.; Sturgeon, G.; Mendonca, S.; Grimes, Jason; Tsui, B. M. W.

2010-01-01

Purpose: The authors develop the 4D extended cardiac-torso (XCAT) phantom for multimodality imaging research. Methods: Highly detailed whole-body anatomies for the adult male and female were defined in the XCAT using nonuniform rational B-spline (NURBS) and subdivision surfaces based on segmentation of the Visible Male and Female anatomical datasets from the National Library of Medicine as well as patient datasets. Using the flexibility of these surfaces, the Visible Human anatomies were transformed to match body measurements and organ volumes for a 50th percentile (height and weight) male and female. The desired body measurements for the models were obtained using the PEOPLESIZE program that contains anthropometric dimensions categorized from 1st to the 99th percentile for US adults. The desired organ volumes were determined from ICRP Publication 89 [ICRP, ‘‘Basic anatomical and physiological data for use in radiological protection: reference values,” ICRP Publication 89 (International Commission on Radiological Protection, New York, NY, 2002)]. The male and female anatomies serve as standard templates upon which anatomical variations may be modeled in the XCAT through user-defined parameters. Parametrized models for the cardiac and respiratory motions were also incorporated into the XCAT based on high-resolution cardiac- and respiratory-gated multislice CT data. To demonstrate the usefulness of the phantom, the authors show example simulation studies in PET, SPECT, and CT using publicly available simulation packages. Results: As demonstrated in the pilot studies, the 4D XCAT (which includes thousands of anatomical structures) can produce realistic imaging data when combined with accurate models of the imaging process. With the flexibility of the NURBS surface primitives, any number of different anatomies, cardiac or respiratory motions or patterns, and spatial resolutions can be simulated to perform imaging research. Conclusions: With the ability to produce realistic, predictive 3D and 4D imaging data from populations of normal and abnormal patients under various imaging parameters, the authors conclude that the XCAT provides an important tool in imaging research to evaluate and improve imaging devices and techniques. In the field of x-ray CT, the phantom may also provide the necessary foundation with which to optimize clinical CT applications in terms of image quality versus radiation dose, an area of research that is becoming more significant with the growing use of CT. PMID:20964209

ICRP Publication 134: Occupational Intakes of Radionuclides: Part 2.

PubMed

Paquet, F; Bailey, M R; Leggett, R W; Lipsztein, J; Fell, T P; Smith, T; Nosske, D; Eckerman, K F; Berkovski, V; Ansoborlo, E; Giussani, A; Bolch, W E; Harrison, J D

2016-12-01

The 2007 Recommendations of the International Commission on Radiological Protection (ICRP, 2007) introduced changes that affect the calculation of effective dose, and implied a revision of the dose coefficients for internal exposure, published previously in the Publication 30 series (ICRP, 1979, 1980, 1981, 1988b) and Publication 68 (ICRP, 1994b). In addition, new data are available that support an update of the radionuclide-specific information given in Publications 54 and 78 (ICRP, 1988a, 1997b) for the design of monitoring programmes and retrospective assessment of occupational internal doses. Provision of new biokinetic models, dose coefficients, monitoring methods, and bioassay data was performed by Committee 2, Task Group 21 on Internal Dosimetry, and Task Group 4 on Dose Calculations. A new series, the Occupational Intakes of Radionuclides (OIR) series, will replace the Publication 30 series and Publications 54, 68, and 78. Part 1 of the OIR series has been issued (ICRP, 2015), and describes the assessment of internal occupational exposure to radionuclides, biokinetic and dosimetric models, methods of individual and workplace monitoring, and general aspects of retrospective dose assessment. The following publications in the OIR series (Parts 2–5) will provide data on individual elements and their radioisotopes, including information on chemical forms encountered in the workplace; a list of principal radioisotopes and their physical half-lives and decay modes; the parameter values of the reference biokinetic model; and data on monitoring techniques for the radioisotopes encountered most commonly in workplaces. Reviews of data on inhalation, ingestion, and systemic biokinetics are also provided for most of the elements. Dosimetric data provided in the printed publications of the OIR series include tables of committed effective dose per intake (Sv per Bq intake) for inhalation and ingestion, tables of committed effective dose per content (Sv per Bq measurement) for inhalation, and graphs of retention and excretion data per Bq intake for inhalation. These data are provided for all absorption types and for the most common isotope(s) of each element. The electronic annex that accompanies the OIR series of reports contains a comprehensive set of committed effective and equivalent dose coefficients, committed effective dose per content functions, and reference bioassay functions. Data are provided for inhalation, ingestion, and direct input to blood. The present publication provides the above data for the following elements: hydrogen (H), carbon (C), phosphorus (P), sulphur (S), calcium (Ca), iron (Fe), cobalt (Co), zinc (Zn), strontium (Sr), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), and technetium (Tc).

Monte Carlo estimation of radiation dose in organs of female and male adult phantoms due to FDG-F18 absorbed in the lungs

NASA Astrophysics Data System (ADS)

Belinato, Walmir; Santos, William S.; Silva, Rogério M. V.; Souza, Divanizia N.

2014-03-01

The determination of dose conversion factors (S values) for the radionuclide fluorodeoxyglucose (18F-FDG) absorbed in the lungs during a positron emission tomography (PET) procedure was calculated using the Monte Carlo method (MCNPX version 2.7.0). For the obtained dose conversion factors of interest, it was considered a uniform absorption of radiopharmaceutical by the lung of a healthy adult human. The spectrum of fluorine was introduced in the input data file for the simulation. The simulation took place in two adult phantoms of both sexes, based on polygon mesh surfaces called FASH and MASH with anatomy and posture according to ICRP 89. The S values for the 22 internal organs/tissues, chosen from ICRP No. 110, for the FASH and MASH phantoms were compared with the results obtained from a MIRD V phantoms called ADAM and EVA used by the Committee on Medical Internal Radiation Dose (MIRD). We observed variation of more than 100% in S values due to structural anatomical differences in the internal organs of the MASH and FASH phantoms compared to the mathematical phantom.

A biokinetic model for {sup 137}Cs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Melo, D.R.; Lipsztein, J.L.; Oliveira, C.A.N.

1997-08-01

An improved biokinetic model for {sup 137}Cs in humans was developed based on an analysis of data obtained from individuals internally contaminated during an accident in Goiania, Brazil, and other data. Seventeen children (ten girls and seven boys 1-10 y old), ten adolescents (four females and six males), and thirty adults, (fifteen females and fifteen males) contaminated in the accident in Goiania contributed to this study. {sup 137}Cs retention was determined through periodic measurements in a whole-body counter. In addition to the data on {sup 137}Cs retention from these individuals, data from a study on the metabolism of {sup 137}Csmore » in immature, adult, and aged Beagle dogs and data from the literature were used in the formulation of the {sup 137}Cs biokinetic model presented. Mathematically, the retention of cesium is described by three exponential terms, and the retention model is based on a step function of body weight. When the ICRP Publication 56 model for cesium was compared to the model suggested in this paper, it was determined that the ICRP model predicts lower effective doses in 5-y-old children and higher effective doses in infants, adolescents, and adults.« less

EDITORIAL: Roberts Prize for the best paper published in 2011 Roberts Prize for the best paper published in 2011

NASA Astrophysics Data System (ADS)

Cherry, Simon; Ruffle, Jon

2012-08-01

The publishers of Physics in Medicine and Biology (PMB), IOP Publishing, in association with the journal owners, the Institute of Physics and Engineering in Medicine (IPEM), jointly award an annual prize for the best paper published in PMB during the previous year. The procedure for deciding the winner is a two-stage process. First, a shortlist of contenders is drawn up based on those papers that had the best referees' quality assessments, with a further quality check and endorsement by the Editorial Board. The papers on the shortlist are then reviewed by a specially convened IPEM committee consisting of members with fellow status. This committee reads the shortlisted papers and selects the winner. We have much pleasure in advising readers that the Roberts Prize for the best paper published in 2011 is awarded to Matthew Hough et al from the University of Florida, the Francis Marion University and the National Cancer Institute, USA for their paper on a comprehensive electron dosimetry model of skeletal tissues in the adult male: An image-based skeletal dosimetry model for the ICRP reference adult male—internal electron sources 2011 Phys. Med. Biol. 56 2309 Matthew Hough1, Perry Johnson1, Didier Rajon2, Derek Jokisch3, Choonsik Lee4 and Wesley Bolch1,5 1Department of Nuclear and Radiological Engineering, University of Florida, Gainesville, FL, USA 2Department of Neurosurgery, University of Florida, Gainesville, FL, USA 3Department of Physics and Astronomy, Francis Marion University, Florence, SC, USA 4Radiation Epidemiology Branch, National Cancer Institute, Bethesda, MD, USA 5Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA Bone marrow is one of the more radiosensitive tissues in the human body and is housed within a complex structure of bone. This paper describes a comprehensive model of energy deposition by internal electron or beta particle emitters for the ICRP reference adult male based upon ex vivo CT and microCT images of bone from a male cadaver. This work will be important for both the assessment of skeletal doses in radiation protection and nuclear medicine, and also for following external photon irradiation in medical imaging and radiotherapy. Our congratulations go to these authors. Of course all of the shortlisted papers were of an extremely high standard, and they are listed below in alphabetical order. We also would like to thank the IPEM Committee members for their hard work in reading the papers and making what must have been a difficult decision. Simon R Cherry Editor-in-Chief Jon Ruffle Publisher References Hough M, Johnson P, Rajon D, Jokisch D, Lee C and Bolch W 2011 An image-based skeletal dosimetry model for the ICRP reference adult male—internal electron sources Phys. Med. Biol. 56 2309 Jan S 2011 GATE V6: a major enhancement of the GATE simulation platform enabling modelling of CT and radiotherapy Phys. Med. Biol. 56 881 Jing H, Yang Y, and Nishikawa R M 2011 Detection of clustered microcalcifications using spatial point process modeling Phys. Med. Biol. 56 1 Li T, Thongphiew D, Zhu X, Lee W R, Vujaskovic Z, Yin F-F, Wu Q J A 2011 Adaptive prostate IGRT combining online re-optimization and re-positioning: a feasibility study Phys. Med. Biol. 56 1243 Kitchen M J, Paganin D M, Uesugi K, Allison B J, Lewis R A, Hooper S B, Pavlov K M 2011 Phase contrast image segmentation using a Laue analyser crystal Phys. Med. Biol. 56 515 Yamaya T, Mitsuhashi T, Matsumoto T, Inadama N, Nishikido F, Yoshida E, Murayama H, Kawai H, Suga M and Watanabe M 2011 A SiPM-based isotropic-3D PET detector X'tal cube with a three-dimensional array of 1 mm3 crystals Phys. Med. Biol. 56 6793 Yu Z, Wunderlich A, Dennerlein F, Lauritsch G and Noo F 2011 Line plus arc source trajectories and their R-line coverage for long-object cone-beam imaging with a C-arm system Phys. Med. Biol. 56 3447

Organ dose conversion coefficients for pediatric reference computational phantoms in external photon radiation fields

NASA Astrophysics Data System (ADS)

Chang, Lienard A.

In the event of a radiological accident or attack, it is important to estimate the organ doses to those exposed. In general, it is difficult to measure organ dose directly in the field and therefore dose conversion coefficients (DCC) are needed to convert measurable values such as air kerma to organ dose. Previous work on these coefficients has been conducted mainly for adults with a focus on radiation protection workers. Hence, there is a large gap in the literature for pediatric values. This study coupled a Monte Carlo N-Particle eXtended (MCNPX) code with International Council of Radiological Protection (ICRP)-adopted University of Florida and National Cancer Institute pediatric reference phantoms to calculate a comprehensive list of dose conversion coefficients (mGy/mGy) to convert air-kerma to organ dose. Parameters included ten phantoms (newborn, 1-year, 5-year, 10-year, 15-year old male and female), 28 organs over 33 energies between 0.01 and 20 MeV in six (6) irradiation geometries relevant to a child who might be exposed to a radiological release: anterior-posterior (AP), posterior-anterior (PA), right-lateral (RLAT), left-lateral (LLAT), rotational (ROT), and isotropic (ISO). Dose conversion coefficients to the red bone marrow over 36 skeletal sites were also calculated. It was hypothesized that the pediatric organ dose conversion coefficients would follow similar trends to the published adult values as dictated by human anatomy, but be of a higher magnitude. It was found that while the pediatric coefficients did yield similar patterns to that of the adult coefficients, depending on the organ and irradiation geometry, the pediatric values could be lower or higher than that of the adult coefficients.

Estimation of absorbed fraction to the anterior nose from inhaled beta emitters

NASA Astrophysics Data System (ADS)

Moussa, Hanna Moussa

2000-08-01

The main purpose of this research is to introduce a new and more realistic geometry for the anterior nose region (ET1) as an alternative to the one provided in ICRP Publication 66. For a more accurate estimation of electron absorbed fraction (AF) to the nuclei of basal cells in the ET 1 region, the proposed new geometry (frustum of a cone) replaces the cylinder geometry, which was used in ICRP 66. Since the electron absorbed fraction (AF) data in ICRP 66 are calculated based on the nose size for an adult Caucasian male, a second purpose of this research is to investigate how the nose size (different ethnic groups) and nose tissue composition (male, female and adolescent), affects the electron absorbed fraction values. The third aim of this research is to develop a Monte Carlo program to estimate the electron energies that emerge from the surface of spherical dust particles. Given that electrons can be located anywhere between the center and the surface of the sphere, we vary the sphere radius from 0.5 to 50 μm and investigate the effects of self-absorption on the emitted electron energies and absorbed fraction.

A biokinetic model for systemic technetium in adult humans

DOE PAGES

Leggett, Richard Wayne; Giussani, Augusto

2015-04-10

The International Commission on Radiological Protection (ICRP) currently is updating its biokinetic and dosimetric models for internally deposited radionuclides. Technetium (Tc), the lightest element that exists only in radioactive form, has two important isotopes from the standpoint of potential risk to humans: the long-lived isotope 99Tm(T 1/2=2.1x10 5 y) is present in high concentration in nuclear waste, and the short-lived isotope 99mTc (T 1/2=6.02 h) is the most commonly used radionuclide in diagnostic nuclear medicine. This paper reviews data on the biological behavior of technetium and proposes a biokinetic model for systemic technetium in the adult human body formore » use in radiation protection. Compared with the ICRP s current occupational model for systemic technetium, the proposed model provides a more realistic description of the paths of movement of technetium in the body; provides greater consistency with experimental and medical data; and, for most radiosensitive organs, yields substantially different estimates of cumulative activity (total radioactive decays within the organ) following uptake of 99Tm or 99mTc to blood.« less

Dose estimation of eye lens for interventional procedures in diagnosis

NASA Astrophysics Data System (ADS)

Liu, Yu-Rong; Huang, Chia-Yu; Hsu, Ching-Han; Hsu, Fang-Yuh

2017-11-01

The International Commission on Radiological Protection (ICRP) recommended that the equivalent dose limit for the lens of the eye be decreased from 150 mSv/y (ICRP, 2007) to 20 mSv/y averaged over five years (ICRP, 2011). How to accurately measure the eye-lens dose has, therefore, been an issue of interest recently. Interventional radiologists are at a higher risk of radiation-induced eye injury, such as cataracts, than all other occupational radiation workers. The main objective of this study is to investigate the relationship between the doses to the eye lenses of interventional radiologists measured by different commercial eye-lens dosimeters. This study measured a reference eye-lens dose, which involved placing thermoluminescent dosimeter (TLD) chips at the surface of the eye of the Rando Phantom, and the TLD chips were covered by a 3-mm-thick tissue-equivalent bolus. Commercial eye-lens dosimeters, such as a headband dosimeter and standard personnel dose badges, were placed at the positions recommended by the manufacturers. The results show that the personnel dose badge is not an appropriate dosimeter for evaluating eye-lens dose. Dose deviations for different dosimeters are discussed and presented in this study.

New Stochastic Annual Limits on Intake for Selected Radionuclides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carbaugh, Eugene H.

Annual limits on intake (ALI) have historically been tabulated by the International Commission on Radiological Protection (e.g., ICRP 1979, 1961) and also by the Environmental Protection Agency (EPA 1988). These compilations have been rendered obsolete by more recent ICRP dosimetry methods, and, rather than provide new ALIs, the ICRP has opted instead to provide committed dose coefficients from which an ALI can be determined by a user for a specific set of conditions. The U.S. Department of Energy historically has referenced compilations of ALIs and has defined their method of calculation in its radiation protection regulation (10 CFDR 835), butmore » has never provided a specific compilation. Under June 2007 amendments to 10 CFR 835, ALIs can be calculated by dividing an appropriate dose limit, either 5-rem (0.05 Sv) effective dose or 50 rem (0.5 Sv) equivalent dose to an individual organ or tissue, by an appropriate committed dose coefficient. When based on effective dose, the ALI is often referred to as a stochastic annual limit on intake (SALI), and when based on the individual organ or tissue equivalent limit, it has often been called a deterministic annual limit on intake (DALI).« less

[Diagnostic reference levels in interventional radiology].

PubMed

Vañó Carruana, E; Fernández Soto, J M; Sánchez Casanueva, R M; Ten Morón, J I

2013-12-01

This article discusses the diagnostic reference levels for radiation exposure proposed by the International Commission on Radiological Protection (ICRP) to facilitate the application of the optimization criteria in diagnostic imaging and interventional procedures. These levels are normally established as the third quartile of the dose distributions to patients in an ample sample of centers and are supposed to be representative of good practice regarding patient exposure. In determining these levels, it is important to evaluate image quality as well to ensure that it is sufficient for diagnostic purposes. When the values for the dose received by patients are systematically higher or much lower than the reference levels, an investigation should determine whether corrective measures need to be applied. The European and Spanish regulations require the use of these reference values in quality assurance programs. For interventional procedures, the dose area product (or kerma area product) values are usually used as reference values together with the time under fluoroscopy and the total number of images acquired. The most modern imaging devices allow the value of the accumulated dose at the entrance to the patient to be calculated to optimize the distribution of the dose on the skin. The ICRP recommends that the complexity of interventional procedures be taken into account when establishing reference levels. In the future, diagnostic imaging departments will have automatic systems to manage patient dosimetric data; these systems will enable continuous dosage auditing and alerts about individual procedures that might involve doses several times above the reference values. This article also discusses aspects that need to be clarified to take better advantage of the reference levels in interventional procedures. Copyright © 2013 SERAM. Published by Elsevier Espana. All rights reserved.

Computational lymphatic node models in pediatric and adult hybrid phantoms for radiation dosimetry

NASA Astrophysics Data System (ADS)

Lee, Choonsik; Lamart, Stephanie; Moroz, Brian E.

2013-03-01

We developed models of lymphatic nodes for six pediatric and two adult hybrid computational phantoms to calculate the lymphatic node dose estimates from external and internal radiation exposures. We derived the number of lymphatic nodes from the recommendations in International Commission on Radiological Protection (ICRP) Publications 23 and 89 at 16 cluster locations for the lymphatic nodes: extrathoracic, cervical, thoracic (upper and lower), breast (left and right), mesentery (left and right), axillary (left and right), cubital (left and right), inguinal (left and right) and popliteal (left and right), for different ages (newborn, 1-, 5-, 10-, 15-year-old and adult). We modeled each lymphatic node within the voxel format of the hybrid phantoms by assuming that all nodes have identical size derived from published data except narrow cluster sites. The lymph nodes were generated by the following algorithm: (1) selection of the lymph node site among the 16 cluster sites; (2) random sampling of the location of the lymph node within a spherical space centered at the chosen cluster site; (3) creation of the sphere or ovoid of tissue representing the node based on lymphatic node characteristics defined in ICRP Publications 23 and 89. We created lymph nodes until the pre-defined number of lymphatic nodes at the selected cluster site was reached. This algorithm was applied to pediatric (newborn, 1-, 5-and 10-year-old male, and 15-year-old males) and adult male and female ICRP-compliant hybrid phantoms after voxelization. To assess the performance of our models for internal dosimetry, we calculated dose conversion coefficients, called S values, for selected organs and tissues with Iodine-131 distributed in six lymphatic node cluster sites using MCNPX2.6, a well validated Monte Carlo radiation transport code. Our analysis of the calculations indicates that the S values were significantly affected by the location of the lymph node clusters and that the values increased for smaller phantoms due to the shorter inter-organ distances compared to the bigger phantoms. By testing sensitivity of S values to random sampling and voxel resolution, we confirmed that the lymph node model is reasonably stable and consistent for different random samplings and voxel resolutions.

ICRP PUBLICATION 122: radiological protection in geological disposal of long-lived solid radioactive waste.

PubMed

Weiss, W; Larsson, C-M; McKenney, C; Minon, J-P; Mobbs, S; Schneider, T; Umeki, H; Hilden, W; Pescatore, C; Vesterlind, M

2013-06-01

This report updates and consolidates previous recommendations of the International Commission on Radiological Protection (ICRP) related to solid waste disposal (ICRP, 1985, 1997b, 1998). The recommendations given apply specifically to geological disposal of long-lived solid radioactive waste. The report explains how the ICRP system of radiological protection described in Publication 103 (ICRP, 2007) can be applied in the context of the geological disposal of long-lived solid radioactive waste. Although the report is written as a standalone document, previous ICRP recommendations not dealt with in depth in the report are still valid. The 2007 ICRP system of radiological protection evolves from the previous process-based protection approach relying on the distinction between practices and interventions by moving to an approach based on the distinction between three types of exposure situation: planned, emergency and existing. The Recommendations maintains the Commission's three fundamental principles of radiological protection namely: justification, optimisation of protection and the application of dose limits. They also maintain the current individual dose limits for effective dose and equivalent dose from all regulated sources in planned exposure situations. They re-enforce the principle of optimisation of radiological protection, which applies in a similar way to all exposure situations, subject to restrictions on individual doses: constraints for planned exposure situations, and reference levels for emergency and existing exposure situations. The Recommendations also include an approach for developing a framework to demonstrate radiological protection of the environment. This report describes the different stages in the life time of a geological disposal facility, and addresses the application of relevant radiological protection principles for each stage depending on the various exposure situations that can be encountered. In particular, the crucial factor that influences the application of the protection system over the different phases in the life time of a disposal facility is the level of oversight or 'watchful care' that is present. The level of oversight affects the capability to control the source, i.e. the waste and the repository, and to avoid or reduce potential exposures. Three main time frames are considered: time of direct oversight, when the disposal facility is being implemented and is under active supervision; time of indirect oversight, when the disposal facility is sealed and oversight is being exercised by regulators or special administrative bodies or society at large to provide additional assurance on behalf of society; and time of no oversight, when oversight is no longer exercised in case memory of the disposal facility is lost. Copyright © 2013. Published by Elsevier Ltd.

Uranium levels in the diet of São Paulo City residents.

PubMed

Garcia, F; Barioni, A; Arruda-Neto, J D T; Deppman, A; Milian, F; Mesa, J; Rodriguez, O

2006-07-01

Natural levels of uranium in the diet of São Paulo City residents were studied, and radionuclide concentrations were measured by the fission track method on samples of typical adult food items. This information was used to evaluate the daily intake of uranium in individuals living in São Paulo City which is, according to our findings, around 0.97 microg U/day. Using the ICRP Uranium-model, we estimated the uranium accumulation and committed doses in some tissues and organs, as function of time. We compared the output of the ICRP uranium biokinetic model, tailored for the conditions prevailing in São Paulo, with experimental data from other localities. Such comparison was possible by means of a simple method we developed, which allows normalization among experimental results from different regions where distinct values of chronic daily intake are observed.

Impact of the new nuclear decay data of ICRP publication 107 on inhalation dose coefficients for workers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manabe, K.; Endo, Akira; Eckerman, Keith F

2010-03-01

The impact a revision of nuclear decay data had on dose coefficients was studied using data newly published in ICRP Publication 107 (ICRP 107) and existing data from ICRP Publication 38 (ICRP 38). Committed effective dose coefficients for occupational inhalation of radionuclides were calculated using two sets of decay data with the dose and risk calculation software DCAL for 90 elements, 774 nuclides and 1572 cases. The dose coefficients based on ICRP 107 increased by over 10 % compared with those based on ICRP 38 in 98 cases, and decreased by over 10 % in 54 cases. It was foundmore » that the differences in dose coefficients mainly originated from changes in the radiation energy emitted per nuclear transformation. In addition, revisions of the half-lives, radiation types and decay modes also resulted in changes in the dose coefficients.« less

Analysis of linear energy transfers and quality factors of charged particles produced by spontaneous fission neutrons from 252Cf and 244Pu in the human body.

PubMed

Endo, Akira; Sato, Tatsuhiko

2013-04-01

Absorbed doses, linear energy transfers (LETs) and quality factors of secondary charged particles in organs and tissues, generated via the interactions of the spontaneous fission neutrons from (252)Cf and (244)Pu within the human body, were studied using the Particle and Heavy Ion Transport Code System (PHITS) coupled with the ICRP Reference Phantom. Both the absorbed doses and the quality factors in target organs generally decrease with increasing distance from the source organ. The analysis of LET distributions of secondary charged particles led to the identification of the relationship between LET spectra and target-source organ locations. A comparison between human body-averaged mean quality factors and fluence-averaged radiation weighting factors showed that the current numerical conventions for the radiation weighting factors of neutrons, updated in ICRP103, and the quality factors for internal exposure are valid.

Reliability of a new biokinetic model of zirconium in internal dosimetry: part I, parameter uncertainty analysis.

PubMed

Li, Wei Bo; Greiter, Matthias; Oeh, Uwe; Hoeschen, Christoph

2011-12-01

The reliability of biokinetic models is essential in internal dose assessments and radiation risk analysis for the public, occupational workers, and patients exposed to radionuclides. In this paper, a method for assessing the reliability of biokinetic models by means of uncertainty and sensitivity analysis was developed. The paper is divided into two parts. In the first part of the study published here, the uncertainty sources of the model parameters for zirconium (Zr), developed by the International Commission on Radiological Protection (ICRP), were identified and analyzed. Furthermore, the uncertainty of the biokinetic experimental measurement performed at the Helmholtz Zentrum München-German Research Center for Environmental Health (HMGU) for developing a new biokinetic model of Zr was analyzed according to the Guide to the Expression of Uncertainty in Measurement, published by the International Organization for Standardization. The confidence interval and distribution of model parameters of the ICRP and HMGU Zr biokinetic models were evaluated. As a result of computer biokinetic modelings, the mean, standard uncertainty, and confidence interval of model prediction calculated based on the model parameter uncertainty were presented and compared to the plasma clearance and urinary excretion measured after intravenous administration. It was shown that for the most important compartment, the plasma, the uncertainty evaluated for the HMGU model was much smaller than that for the ICRP model; that phenomenon was observed for other organs and tissues as well. The uncertainty of the integral of the radioactivity of Zr up to 50 y calculated by the HMGU model after ingestion by adult members of the public was shown to be smaller by a factor of two than that of the ICRP model. It was also shown that the distribution type of the model parameter strongly influences the model prediction, and the correlation of the model input parameters affects the model prediction to a certain extent depending on the strength of the correlation. In the case of model prediction, the qualitative comparison of the model predictions with the measured plasma and urinary data showed the HMGU model to be more reliable than the ICRP model; quantitatively, the uncertainty model prediction by the HMGU systemic biokinetic model is smaller than that of the ICRP model. The uncertainty information on the model parameters analyzed in this study was used in the second part of the paper regarding a sensitivity analysis of the Zr biokinetic models.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang Yakun; Li Xiang; Paul Segars, W.

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 representativemore » 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 male and female stylized phantoms. Results: For fully irradiated organs, average coefficients of variation (COV) ranged from 0.07 to 0.22 across the four male phantoms and from 0.06 to 0.18 across the four female phantoms; for partially irradiated organs, average COV ranged from 0.13 to 0.30 across the four male phantoms and from 0.15 to 0.30 across the four female phantoms. Doses to the testes, breasts, and esophagus showed large variations between phantoms. COV for gender-averaged effective dose and k factor ranged from 0.03 to 0.23 and from 0.06 to 0.30, respectively. COV for male risk index and q factor ranged from 0.06 to 0.30 and from 0.05 to 0.36, respectively; COV for female risk index and q factor ranged from 0.06 to 0.49 and from 0.07 to 0.54, respectively. Conclusions: Despite closely matched organ mass, total body weight, and height, large differences in organ dose exist due to variation in organ location, spatial distribution, and dose approximation method. Dose differences for fully irradiated radiosensitive organs were much smaller than those for partially irradiated organs. Weighted dosimetry quantities including effective dose, male risk indices, k factors, and male q factors agreed well across phantoms. The female risk indices and q factors varied considerably across phantoms.« less

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

PubMed Central

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 male and female stylized phantoms. Results: For fully irradiated organs, average coefficients of variation (COV) ranged from 0.07 to 0.22 across the four male phantoms and from 0.06 to 0.18 across the four female phantoms; for partially irradiated organs, average COV ranged from 0.13 to 0.30 across the four male phantoms and from 0.15 to 0.30 across the four female phantoms. Doses to the testes, breasts, and esophagus showed large variations between phantoms. COV for gender-averaged effective dose and k factor ranged from 0.03 to 0.23 and from 0.06 to 0.30, respectively. COV for male risk index and q factor ranged from 0.06 to 0.30 and from 0.05 to 0.36, respectively; COV for female risk index and q factor ranged from 0.06 to 0.49 and from 0.07 to 0.54, respectively. Conclusions: Despite closely matched organ mass, total body weight, and height, large differences in organ dose exist due to variation in organ location, spatial distribution, and dose approximation method. Dose differences for fully irradiated radiosensitive organs were much smaller than those for partially irradiated organs. Weighted dosimetry quantities including effective dose, male risk indices, k factors, and male q factors agreed well across phantoms. The female risk indices and q factors varied considerably across phantoms. PMID:22755721

New Radiation Dosimetry Estimates for [18F]FLT based on Voxelized Phantoms.

PubMed

Mendes, B M; Ferreira, A V; Nascimento, L T C; Ferreira, S M Z M D; Silveira, M B; Silva, J B

2018-04-25

3'-Deoxy-3-[ 18 F]fluorothymidine, or [ 18 F]FLT, is a positron emission tomography (PET) tracer used in clinical studies for noninvasive assessment of proliferation activity in several types of cancer. Although the use of this PET tracer is expanding, to date, few studies concerning its dosimetry have been published. In this work, new [ 18 F]FLT dosimetry estimates are determined for human and mice using Monte Carlo simulations. Modern voxelized male and female phantoms and [ 18 F]FLT biokinetic data, both published by the ICRP, were used for simulations of human cases. For most human organs/tissues the absorbed doses were higher than those reported in ICRP Publication 128. An effective dose of 1.70E-02 mSv/MBq to the whole body was determined, which is 13.5% higher than the ICRP reference value. These new human dosimetry estimates obtained using more realistic human phantoms represent an advance in the knowledge of [ 18 F]FLT dosimetry. In addition, mice biokinetic data were obtained experimentally. These data and a previously developed voxelized mouse phantom were used for simulations of animal cases. Concerning animal dosimetry, absorbed doses for organs/tissues ranged from 4.47 ± 0.75 to 155.74 ± 59.36 mGy/MBq. The obtained set of organ/tissue radiation doses for healthy Swiss mice is a useful tool for application in animal experiment design.

Ethos in Fukushima and the ICRP dialogue seminars.

PubMed

Ando, R

2016-12-01

Ethos in Fukushima, a non-profit organisation, participated in 10 of the 12 International Commission on Radiological Protection (ICRP) dialogue seminars over the past 4 years. The slides and videos that were shown at the seminars are recorded on the Ethos in Fukushima website ( http://ethos-fukushima.blogspot.jp/p/icrp-dialogue.html ). I would like to introduce the activities of Ethos in Fukushima to date, and explain why the ICRP dialogue materials have come to be published on its website.

Transfer parameters for ICRP's Reference Animals and Plants in a terrestrial Mediterranean ecosystem.

PubMed

Guillén, J; Beresford, N A; Baeza, A; Izquierdo, M; Wood, M D; Salas, A; Muñoz-Serrano, A; Corrales-Vázquez, J M; Muñoz-Muñoz, J G

2018-06-01

A system for the radiological protection of the environment (or wildlife) based on Reference Animals and Plants (RAPs) has been suggested by the International Commission on Radiological Protection (ICRP). To assess whole-body activity concentrations for RAPs and the resultant internal dose rates, transfer parameters are required. However, transfer values specifically for the taxonomic families defined for the RAPs are often sparse and furthermore can be extremely site dependent. There is also a considerable geographical bias within available transfer data, with few data for Mediterranean ecosystems. In the present work, stable element concentrations (I, Li, Be, B, Na, Mg, Al, P, S, K. Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, Cs, Ba, Tl, Pb and U) in terrestrial RAPs, and the corresponding whole-body concentration ratios, CR wo , were determined in two different Mediterranean ecosystems: a Pinewood and a Dehesa (grassland with disperse tree cover). The RAPs considered in the Pinewood ecosystem were Pine Tree and Wild Grass; whereas in the Dehesa ecosystem those considered were Deer, Rat, Earthworm, Bee, Frog, Duck and Wild Grass. The CR wo values estimated from these data are compared to those reported in international compilations and databases. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Estimation and comparison of effective dose (E) in standard chest CT by organ dose measurements and dose-length-product methods and assessment of the influence of CT tube potential (energy dependency) on effective dose in a dual-source CT.

PubMed

Paul, Jijo; Banckwitz, Rosemarie; Krauss, Bernhard; Vogl, Thomas J; Maentele, Werner; Bauer, Ralf W

2012-04-01

To determine effective dose (E) during standard chest CT using an organ dose-based and a dose-length-product-based (DLP) approach for four different scan protocols including high-pitch and dual-energy in a dual-source CT scanner of the second generation. Organ doses were measured with thermo luminescence dosimeters (TLD) in an anthropomorphic male adult phantom. Further, DLP-based dose estimates were performed by using the standard 0.014mSv/mGycm conversion coefficient k. Examinations were performed on a dual-source CT system (Somatom Definition Flash, Siemens). Four scan protocols were investigated: (1) single-source 120kV, (2) single-source 100kV, (3) high-pitch 120kV, and (4) dual-energy with 100/Sn140kV with equivalent CTDIvol and no automated tube current modulation. E was then determined following recommendations of ICRP publication 103 and 60 and specific k values were derived. DLP-based estimates differed by 4.5-16.56% and 5.2-15.8% relatively to ICRP 60 and 103, respectively. The derived k factors calculated from TLD measurements were 0.0148, 0.015, 0.0166, and 0.0148 for protocol 1, 2, 3 and 4, respectively. Effective dose estimations by ICRP 103 and 60 for single-energy and dual-energy protocols show a difference of less than 0.04mSv. Estimates of E based on DLP work equally well for single-energy, high-pitch and dual-energy CT examinations. The tube potential definitely affects effective dose in a substantial way. Effective dose estimations by ICRP 103 and 60 for both single-energy and dual-energy examinations differ not more than 0.04mSv. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Human biokinetic data and a new compartmental model of zirconium--a tracer study with enriched stable isotopes.

PubMed

Greiter, Matthias B; Giussani, Augusto; Höllriegl, Vera; Li, Wei Bo; Oeh, Uwe

2011-09-01

Biokinetic models describing the uptake, distribution and excretion of trace elements are an essential tool in nutrition, toxicology, or internal dosimetry of radionuclides. Zirconium, especially its radioisotope (95)Zr, is relevant to radiation protection due to its production in uranium fission and neutron activation of nuclear fuel cladding material. We present a comprehensive set of human data from a tracer study with stable isotopes of zirconium. The data are used to refine a biokinetic model of zirconium. Six female and seven male healthy adult volunteers participated in the study. It includes 16 complete double tracer investigations with oral ingestion and intravenous injection, and seven supplemental investigations. Tracer concentrations were measured in blood plasma and urine collected up to 100 d after tracer administration. The four data sets (two chemical tracer forms in plasma and urine) each encompass 105-240 measured concentration values above detection limits. Total fractional absorption of ingested zirconium was found to be 0.001 for zirconium in citrate-buffered drinking solution and 0.007 for zirconium oxalate solution. Biokinetic models were developed based on the linear first-order kinetic compartmental model approach used by the International Commission on Radiological Protection (ICRP). The main differences of the optimized systemic model of zirconium to the current ICRP model are (1) recycling into the transfer compartment made necessary by the observed tracer clearance from plasma, (2) different parameters related to fractional absorption for each form of the ingested tracer, and (3) a physiologically based excretion pathway to urine. The study considerably expands the knowledge on the biokinetics of zirconium, which was until now dominated by data from animal studies. The proposed systemic model improves the existing ICRP model, yet is based on the same principles and fits well into the ICRP radiation protection approach. Copyright © 2011 Elsevier B.V. All rights reserved.

INDOS: conversational computer codes to implement ICRP-10-10A models for estimation of internal radiation dose to man

DOE Office of Scientific and Technical Information (OSTI.GOV)

Killough, G.G.; Rohwer, P.S.

1974-03-01

INDOS1, INDOS2, and INDOS3 (the INDOS codes) are conversational FORTRAN IV programs, implemented for use in time-sharing mode on the ORNL PDP-10 System. These codes use ICRP10-10A models to estimate the radiation dose to an organ of the body of Reference Man resulting from the ingestion or inhalation of any one of various radionuclides. Two patterns of intake are simulated: intakes at discrete times and continuous intake at a constant rate. The IND0S codes provide tabular output of dose rate and dose vs time, graphical output of dose vs time, and punched-card output of organ burden and dose vs time.more » The models of internal dose calculation are discussed and instructions for the use of the INDOS codes are provided. The INDOS codes are available from the Radiation Shielding Information Center, Oak Ridge National Laboratory, P. O. Box X, Oak Ridge, Tennessee 37830. (auth)« less

A generic biokinetic model for noble gases with application to radon.

PubMed

Leggett, Rich; Marsh, James; Gregoratto, Demetrio; Blanchardon, Eric

2013-06-01

To facilitate the estimation of radiation doses from intake of radionuclides, the International Commission on Radiological Protection (ICRP) publishes dose coefficients (dose per unit intake) based on reference biokinetic and dosimetric models. The ICRP generally has not provided biokinetic models or dose coefficients for intake of noble gases, but plans to provide such information for (222)Rn and other important radioisotopes of noble gases in a forthcoming series of reports on occupational intake of radionuclides (OIR). This paper proposes a generic biokinetic model framework for noble gases and develops parameter values for radon. The framework is tailored to applications in radiation protection and is consistent with a physiologically based biokinetic modelling scheme adopted for the OIR series. Parameter values for a noble gas are based largely on a blood flow model and physical laws governing transfer of a non-reactive and soluble gas between materials. Model predictions for radon are shown to be consistent with results of controlled studies of its biokinetics in human subjects.

A probabilistic safety analysis of incidents in nuclear research reactors.

PubMed

Lopes, Valdir Maciel; Agostinho Angelo Sordi, Gian Maria; Moralles, Mauricio; Filho, Tufic Madi

2012-06-01

This work aims to evaluate the potential risks of incidents in nuclear research reactors. For its development, two databases of the International Atomic Energy Agency (IAEA) were used: the Research Reactor Data Base (RRDB) and the Incident Report System for Research Reactor (IRSRR). For this study, the probabilistic safety analysis (PSA) was used. To obtain the result of the probability calculations for PSA, the theory and equations in the paper IAEA TECDOC-636 were used. A specific program to analyse the probabilities was developed within the main program, Scilab 5.1.1. for two distributions, Fischer and chi-square, both with the confidence level of 90 %. Using Sordi equations, the maximum admissible doses to compare with the risk limits established by the International Commission on Radiological Protection (ICRP) were obtained. All results achieved with this probability analysis led to the conclusion that the incidents which occurred had radiation doses within the stochastic effects reference interval established by the ICRP-64.

The role of the ICRP in radiation protection--a view from industry.

PubMed

Henrichs, K

2003-01-01

It is the objective of this paper to discuss some aspects concerning the role and importance of the ICRP. Here, this is done with a background of practical radiation protection in industry. The author organises and controls radiation protection for a worldwide operating company, for which efficiently realised radiation safety is as relevant for its workplaces as for its products and services. According to the author's subjective observation, the ICRP has a decreasing importance in operational radiation protection. However, there are growing demands on the ICRP as it is the only basis for internationally compatible regulations and standards. It is the merit of the ICRP that an international comparison of legal protection systems and concepts should give a much more homogeneous picture than that for any other safety and protection issue. The most valuable asset of the ICRP is its credibility as a scientific authority solely committed to the effective protection of people. But its success also brings with it an obligation: there is an increasing need for more effective communication to non-experts. This and other expectations for the future are briefly discussed.

Hybrid computational phantoms representing the reference adult male and adult female: construction and applications for retrospective dosimetry.

PubMed

Hurtado, Jorge L; Lee, Choonsik; Lodwick, Daniel; Goede, Timothy; Williams, Jonathan L; Bolch, Wesley E

2012-03-01

Currently, two classes of computational phantoms have been developed for dosimetry calculation: (1) stylized (or mathematical) and (2) voxel (or tomographic) phantoms describing human anatomy through mathematical surface equations and 3D voxel matrices, respectively. Mathematical surface equations in stylized phantoms are flexible, but the resulting anatomy is not as realistic. Voxel phantoms display far better anatomical realism, but they are limited in terms of their ability to alter organ shape, position, and depth, as well as body posture. A new class of computational phantoms called hybrid phantoms takes advantage of the best features of stylized and voxel phantoms-flexibility and anatomical realism, respectively. In the current study, hybrid computational phantoms representing the adult male and female reference anatomy and anthropometry are presented. These phantoms serve as the starting framework for creating patient or worker sculpted whole-body phantoms for retrospective dose reconstruction. Contours of major organs and tissues were converted or segmented from computed tomography images of a 36-y-old Korean volunteer and a 25-y-old U.S. female patient, respectively, with supplemental high-resolution CT images of the cranium. Polygon mesh models for the major organs and tissues were reconstructed and imported into Rhinoceros™ for non-uniform rational B-spline (NURBS) surface modeling. The resulting NURBS/polygon mesh models representing body contour and internal anatomy were matched to anthropometric data and reference organ mass data provided by Centers for Disease Control and Prevention and International Commission on Radiation Protection, respectively. Finally, two hybrid adult male and female phantoms were completed where a total of eight anthropometric data categories were matched to standard values within 4% and organ volumes matched to ICRP data within 1% with the exception of total skin. The hybrid phantoms were voxelized from the NURBS phantoms at resolutions of 0.158 × 0.158 × 0.158 cm and 0.126 × 0.126 × 0.126 cm for the male and female, respectively. To highlight the flexibility of the hybrid phantoms, graphical displays are given of (1) underweight and overweight adult male phantoms, (2) a sitting position for the adult female phantom, and (3) extraction and higher-resolution voxelization of the small intestine for localized dosimetry of mucosal and stem cell layers. These phantoms are used to model radioactively contaminated individuals and to then assess time-dependent detector count rate thresholds corresponding to 50, 250, and 500 mSv effective dose, as might be needed during in-field radiological triage by first responders or first receivers.

Annual limits on intake (ALI) values in ICRP 61 and 10 CFR Part 20 (1991)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, M.; Kearfott, K.J.

The newest major revision of Nuclear Regulatory Commission`s 10 CFR Part 20 (1991) incorporates the new dose methodology system, revised limits, and improved internal dose computations presented in International Commission on Radiation Protection (ICRP) Publication 30 (1979). A year before the issue of this revised 10 CFR Part 20, the ICRP dispatched Publication 61 (1990). This new ICRP report employed different dose limits, in addition to incorporating more recent biological information and variations in physiological and different tissue weighing factors for various organs. An investigation of the numerical differences in the Annual Limit on Intake (ALI) reported in this moremore » recent international regulations and those of the new regulations was thus undertaken. Overall means, medians, modes, maximum, minimum, and ranges of the percent changes are almost identical for ingestion and inhalation, although the percent difference between 10 CFR and ICRP Publication 61 showed minor differences for individual radionuclides. Approximately 334 of 1,351 radionuclides for inhalation and 173 of 771 radionuclides for ingestion have much less restrictive ALIs in the new ICRP recommendations than in the old, with some of those limits increased by at least a factor of two. Approximately 51% of the radionuclides for ingestion intake and 48% of radionuclides for inhalation intake showed changes of greater than 25%. The radionuclides observed to have much less restrictive ALIs are primarily the radionuclides of thorium, mercury, plutonium, uranium, and americium which have short effective clearance rates. While many countries have already applied the ICRP 61 recommendations to their radiation protection standards, using the ICRP 30 recommendation in the United States does not match the international standards even when the values of the ALIs are adjusted for differences in dose limits.« less

The work of the ICRP dose calculational task group: Issues in implementation of the ICRP dosimetric methodology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eckerman, K.F.

Committee 2 of the International Commission on Radiological Protection (ICRP) has had efforts underway to provide the radiation protection community with age-dependent dose coefficients, i.e.g, the dose per unit intake. The Task Group on Dose Calculations, chaired by the author, is responsible for the computation of these coefficients. The Task Group, formed in 1974 to produce ICRP Publication 30, is now international in its membership and its work load has been distributed among the institutions represented on the task group. This paper discusses: (1) recent advances in biokinetic modeling; (2) the recent changes in the dosimetric methodology; (3) the novelmore » computational problems with some of the ICRP quantities; and (4) quality assurance issues which the Task Group has encountered. Potential future developments of the dosimetric framework which might strengthen the relationships with the emerging understanding of radiation risk will also be discussed.« less

Overview of ICRP Committee 5: protection of the environment.

PubMed

Larsson, C-M

2016-06-01

Protection of the environment is integral to the system of radiological protection, as outlined in the 2007 Recommendations of the International Commission on Radiological Protection (ICRP, Publication 103). The Commission's activities in this area are mainly pursued by Committee 5 and its associated Task Groups. Publication 91 broadly outlines the approach to radiological protection of the environment, and its alignment with approaches to environmental protection from hazardous substances in general. Publications 108 and 114 provide the cornerstones of the environmental protection system and relevant databases. Publication 124 considers its application in planned, existing, and emergency exposure situations. The system centres on 12 Reference Animals and Plants (RAPs) with broad relevance for environmental protection based on their ubiquity and significance as well as other criteria, as described in Publication 108 The databases comprise general biology of the RAPs, transfer parameters, dose conversion coefficients, and effects data. Derived Consideration Reference Levels (DCRLs) were established for each RAP; a DCRL represents a band of dose rates that might result in some deleterious effects in individuals of that type of RAP. Newly established Task Group 99 will compile the RAP-specific reference information into monographs, with the view of updating information and improving the applicability of the system in different exposure situations. For certain scenarios, more precise and ecosystem-specific protection benchmarks may be justified, which would have to be informed by consideration of representative organisms (i.e. representative of a particular ecosystem and relevant to the specific scenario; Publication 124). Committee 5 will explore this further, making use of a limited number of case studies. © The International Society for Prosthetics and Orthotics.

MONTE CARLO STUDY OF THE CARDIAC ABSORBED DOSE DURING X-RAY EXAMINATION OF AN ADULT PATIENT.

PubMed

Kadri, O; Manai, K; Alfuraih, A

2016-12-01

The computational voxel phantom 'High-Definition Reference Korean-Man (HDRK-Man)' was implemented into the Monte Carlo transport toolkit Geant4. The voxel model, adjusted to the Reference Korean Man, is 171 cm in height and 68 kg in weight and composed of ∼30 million voxels whose size is 1.981 × 1.981 × 2.0854 mm 3 The Geant4 code is then utilised to compute the dose conversion coefficients (DCCs) expressed in absorbed dose per air kerma free in air for >30 tissues and organs, including almost all organs required in the new recommendation of the ICRP 103, due to a broad parallel beam of monoenergetic photons impinging in antero-postero direction with energy ranging from 10 to 150 keV. The computed DCCs of different organs are found to be in good agreement with data published using other simulation codes. Also, the influence of patient size on DCC values was investigated for a representative body size of the adult Korean patient population. The study was performed using five different sizes covering the range of 0.8-1.2 magnification order of the original HDRK-Man. It focussed on the computation of DCC for the human heart. Moreover, the provided DCCs were used to present an analytical parameterisation for the calculation of the cardiac absorbed dose for any arbitrary X-ray spectrum and for those patient sizes. Thus, the present work can be considered as an enhancement of the continuous studies performed by medical physicist as part of quality control tests and radiation protection dosimetry. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Response functions for computing absorbed dose to skeletal tissues from photon irradiation—an update

NASA Astrophysics Data System (ADS)

Johnson, Perry B.; Bahadori, Amir A.; Eckerman, Keith F.; Lee, Choonsik; Bolch, Wesley E.

2011-04-01

A comprehensive set of photon fluence-to-dose response functions (DRFs) is presented for two radiosensitive skeletal tissues—active and total shallow marrow—within 15 and 32 bone sites, respectively, of the ICRP reference adult male. The functions were developed using fractional skeletal masses and associated electron-absorbed fractions as reported for the UF hybrid adult male phantom, which in turn is based upon micro-CT images of trabecular spongiosa taken from a 40 year male cadaver. The new DRFs expand upon both the original set of seven functions produced in 1985, and a 2007 update calculated under the assumption of secondary electron escape from spongiosa. In this study, it is assumed that photon irradiation of the skeleton will yield charged particle equilibrium across all spongiosa regions at energies exceeding 200 keV. Kerma coefficients for active marrow, inactive marrow, trabecular bone and spongiosa at higher energies are calculated using the DRF algorithm setting the electron-absorbed fraction for self-irradiation to unity. By comparing kerma coefficients and DRF functions, dose enhancement factors and mass energy-absorption coefficient (MEAC) ratios for active marrow to spongiosa were derived. These MEAC ratios compared well with those provided by the NIST Physical Reference Data Library (mean difference of 0.8%), and the dose enhancement factors for active marrow compared favorably with values calculated in the well-known study published by King and Spiers (1985 Br. J. Radiol. 58 345-56) (mean absolute difference of 1.9 percentage points). Additionally, dose enhancement factors for active marrow were shown to correlate well with the shallow marrow volume fraction (R2 = 0.91). Dose enhancement factors for the total shallow marrow were also calculated for 32 bone sites representing the first such derivation for this target tissue.

Response functions for computing absorbed dose to skeletal tissues from photon irradiation--an update.

PubMed

Johnson, Perry B; Bahadori, Amir A; Eckerman, Keith F; Lee, Choonsik; Bolch, Wesley E

2011-04-21

A comprehensive set of photon fluence-to-dose response functions (DRFs) is presented for two radiosensitive skeletal tissues-active and total shallow marrow-within 15 and 32 bone sites, respectively, of the ICRP reference adult male. The functions were developed using fractional skeletal masses and associated electron-absorbed fractions as reported for the UF hybrid adult male phantom, which in turn is based upon micro-CT images of trabecular spongiosa taken from a 40 year male cadaver. The new DRFs expand upon both the original set of seven functions produced in 1985, and a 2007 update calculated under the assumption of secondary electron escape from spongiosa. In this study, it is assumed that photon irradiation of the skeleton will yield charged particle equilibrium across all spongiosa regions at energies exceeding 200 keV. Kerma coefficients for active marrow, inactive marrow, trabecular bone and spongiosa at higher energies are calculated using the DRF algorithm setting the electron-absorbed fraction for self-irradiation to unity. By comparing kerma coefficients and DRF functions, dose enhancement factors and mass energy-absorption coefficient (MEAC) ratios for active marrow to spongiosa were derived. These MEAC ratios compared well with those provided by the NIST Physical Reference Data Library (mean difference of 0.8%), and the dose enhancement factors for active marrow compared favorably with values calculated in the well-known study published by King and Spiers (1985 Br. J. Radiol. 58 345-56) (mean absolute difference of 1.9 percentage points). Additionally, dose enhancement factors for active marrow were shown to correlate well with the shallow marrow volume fraction (R(2) = 0.91). Dose enhancement factors for the total shallow marrow were also calculated for 32 bone sites representing the first such derivation for this target tissue.

RESPONSE FUNCTIONS FOR COMPUTING ABSORBED DOSE TO SKELETAL TISSUES FROM PHOTON IRRADIATION – AN UPDATE

PubMed Central

Johnson, Perry; Bahadori, Amir; Eckerman, Keith; Lee, Choonsik; Bolch, Wesley E.

2014-01-01

A comprehensive set of photon fluence-to-dose response functions (DRFs) are presented for two radiosensitive skeletal tissues – active and total shallow marrow – within 15 and 32 bones sites, respectively, of the ICRP reference adult male. The functions were developed using fractional skeletal masses and associated electron absorbed fractions as reported for the UF hybrid adult male phantom, which in turn is based upon microCT images of trabecular spongiosa taken from a 40-year male cadaver. The new DRFs expand upon both the original set of seven functions produced in 1985, as well as a 2007 update calculated under the assumption of secondary electron escape from spongiosa. In the present study, it is assumed that photon irradiation of the skeleton will yield charged particle equilibrium across all spongiosa regions at energies exceeding 200 keV. Kerma factors for active marrow, inactive marrow, trabecular bone, and spongiosa at higher energies are calculated using the DRF algorithm setting the electron absorbed fraction for self-irradiation to unity. By comparing kerma factors and DRF functions, dose enhancement factors and mass energy-absorption coefficient (MEAC) ratios for active marrow to spongiosa were derived. These MEAC ratios compared well with those provided by the NIST Physical Reference Data Library (mean difference of 0.8%), and the dose enhancement factors for active marrow compared favorably with values calculated in the well-known study published by King and Spiers (1985) (mean absolute difference of 1.9 percentage points). Additionally, dose enhancement factors for active marrow were shown to correlate well with the shallow marrow volume fraction (R2 = 0.91). Dose enhancement factors for the total shallow marrow were also calculated for 32 bone sites PMID:21427484

Comparisons of calculated respiratory tract deposition of particles based on the NCRP/ITRI model and the new ICRP66 model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yeh, Hsu-Chi; Phalen, R.F.; Chang, I.

1995-12-01

The National Council on Radiation Protection and Measurements (NCRP) in the United States and the International Commission on Radiological Protection (ICRP) have been independently reviewing and revising respiratory tract dosimetry models for inhaled radioactive aerosols. The newly proposed NCRP respiratory tract dosimetry model represents a significant change in philosophy from the old ICRP Task Group model. The proposed NCRP model describes respiratory tract deposition, clearance, and dosimetry for radioactive substances inhaled by workers and the general public and is expected to be published soon. In support of the NCRP proposed model, ITRI staff members have been developing computer software. Althoughmore » this software is still incomplete, the deposition portion has been completed and can be used to calculate inhaled particle deposition within the respiratory tract for particle sizes as small as radon and radon progeny ({approximately} 1 nm) to particles larger than 100 {mu}m. Recently, ICRP published their new dosimetric model for the respiratory tract, ICRP66. Based on ICRP66, the National Radiological Protection Board of the UK developed PC-based software, LUDEP, for calculating particle deposition and internal doses. The purpose of this report is to compare the calculated respiratory tract deposition of particles using the NCRP/ITRI model and the ICRP66 model, under the same particle size distribution and breathing conditions. In summary, the general trends of the deposition curves for the two models were similar.« less

Development and test of sets of 3D printed age-specific thyroid phantoms for 131I measurements

NASA Astrophysics Data System (ADS)

Beaumont, Tiffany; Caldeira Ideias, Pedro; Rimlinger, Maeva; Broggio, David; Franck, Didier

2017-06-01

In the case of a nuclear reactor accident the release contains a high proportion of iodine-131 that can be inhaled or ingested by members of the public. Iodine-131 is naturally retained in the thyroid and increases the thyroid cancer risk. Since the radiation induced thyroid cancer risk is greater for children than for adults, the thyroid dose to children should be assessed as accurately as possible. For that purpose direct measurements should be carried out with age-specific calibration factors but, currently, there is no age-specific thyroid phantoms allowing a robust measurement protocol. A set of age-specific thyroid phantoms for 5, 10, 15 year old children and for the adult has been designed and 3D printed. A realistic thyroid shape has been selected and material properties taken into account to simulate the attenuation of biological tissues. The thyroid volumes follow ICRP recommendations and the phantoms also include the trachea and a spine model. Several versions, with or without spine, with our without trachea, with or without age-specific neck have been manufactured, in order to study the influence of these elements on calibration factors. The calibration factor obtained with the adult phantom and a reference phantom are in reasonable agreement. In vivo calibration experiments with germanium detectors have shown that the difference in counting efficiency, the inverse of the calibration factor, between the 5 year and adult phantoms is 25% for measurement at contact. It is also experimentally evidenced that the inverse of the calibration factor varies linearly with the thyroid volume. The influence of scattering elements like the neck or spine is not evidenced by experimental measurements.

Evaluation of radiation dose to anthropomorphic paediatric models from positron-emitting labelled tracers

NASA Astrophysics Data System (ADS)

Xie, Tianwu; Zaidi, Habib

2014-03-01

PET uses specific molecules labelled with positron-emitting radionuclides to provide valuable biochemical and physiological information. However, the administration of radiotracers to patients exposes them to low-dose ionizing radiation, which is a concern in the paediatric population since children are at a higher cancer risk from radiation exposure than adults. Therefore, radiation dosimety calculations for commonly used positron-emitting radiotracers in the paediatric population are highly desired. We evaluate the absorbed dose and effective dose for 19 positron-emitting labelled radiotracers in anthropomorphic paediatric models including the newborn, 1-, 5-, 10- and 15-year-old male and female. This is achieved using pre-calculated S-values of positron-emitting radionuclides of UF-NCI paediatric phantoms and published biokinetic data for various radiotracers. The influence of the type of anthropomorphic model, tissue weight factors and direct human- versus mouse-derived biokinetic data on the effective dose for paediatric phantoms was also evaluated. In the case of 18F-FDG, dosimetry calculations of reference paediatric patients from various dose regimens were also calculated. Among the considered radiotracers, 18F-FBPA and 15O-water resulted in the highest and lowest effective dose in the paediatric phantoms, respectively. The ICRP 103 updated tissue-weighting factors decrease the effective dose in most cases. Substantial differences of radiation dose were observed between direct human- versus mouse-derived biokinetic data. Moreover, the effect of using voxel- versus MIRD-type models on the calculation of the effective dose was also studied. The generated database of absorbed organ dose and effective dose for various positron-emitting labelled radiotracers using new generation computational models and the new ICRP tissue-weighting factors can be used for the assessment of radiation risks to paediatric patients in clinical practice. This work also contributes to a better understanding of the factors influencing patient-specific radiation dose calculation.

Effect of blood activity on dosimetric calculations for radiopharmaceuticals

NASA Astrophysics Data System (ADS)

Zvereva, Alexandra; Petoussi-Henss, Nina; Li, Wei Bo; Schlattl, Helmut; Oeh, Uwe; Zankl, Maria; Graner, Frank Philipp; Hoeschen, Christoph; Nekolla, Stephan G.; Parodi, Katia; Schwaiger, Markus

2016-11-01

The objective of this work was to investigate the influence of the definition of blood as a distinct source on organ doses, associated with the administration of a novel radiopharmaceutical for positron emission tomography-computed tomography (PET/CT) imaging—(S)-4-(3-18F-fluoropropyl)-L-glutamic acid (18F-FSPG). Personalised pharmacokinetic models were constructed based on clinical PET/CT images from five healthy volunteers and blood samples from four of them. Following an identifiability analysis of the developed compartmental models, person-specific model parameters were estimated using the commercial program SAAM II. Organ doses were calculated in accordance to the formalism promulgated by the Committee on Medical Internal Radiation Dose (MIRD) and the International Commission on Radiological Protection (ICRP) using specific absorbed fractions for photons and electrons previously derived for the ICRP reference adult computational voxel phantoms. Organ doses for two concepts were compared: source organ activities in organs parenchyma with blood as a separate source (concept-1); aggregate activities in perfused source organs without blood as a distinct source (concept-2). Aggregate activities comprise the activities of organs parenchyma and the activity in the regional blood volumes (RBV). Concept-1 resulted in notably higher absorbed doses for most organs, especially non-source organs with substantial blood contents, e.g. lungs (92% maximum difference). Consequently, effective doses increased in concept-1 compared to concept-2 by 3-10%. Not considering the blood as a distinct source region leads to an underestimation of the organ absorbed doses and effective doses. The pronounced influence of the blood even for a radiopharmaceutical with a rapid clearance from the blood, such as 18F-FSPG, suggests that blood should be introduced as a separate compartment in most compartmental pharmacokinetic models and blood should be considered as a distinct source in dosimetric calculations. Hence, blood samples should be included in all pharmacokinetic and dosimetric studies for new tracers if possible.

The evolution of the international system of radiological protection: stakeholder views from the 1st and 2nd NEA/ICRP fora.

PubMed

Lazo, Ted

2003-12-01

The Nuclear Energy Agency's (NEA's) Committee on Radiological Protection and Public Health (CRPPH) has collaborated closely with the ICRP in its efforts to develop new recommendations for radiological protection at the start of the 21st century. As part of this effort, the NEA organised, in collaboration with the ICRP, two fora to discuss the radiological protection of the environment (Taormina, February 2002) and the future policy for radiological protection (Lanzarote, April 2003). Both these meetings were attended by a broad representation of stakeholders. The CRPPH and other stakeholders universally appreciated the opportunity to speak directly with the ICRP on these important subjects. This report summarises the main conclusions made during these two meetings to advance the deliberations of the ICRP to create a new set of recommendations responsive to stakeholder needs, firmly rooted in science, and that can be implemented in a timely, efficient and cost-effective manner.

Evolution of the Radiological Protection System and its Implementation.

PubMed

Lazo, Edward

2016-02-01

The International System of Radiological Protection, developed, maintained, and elaborated by the International Commission on Radiological Protection (ICRP) has, for the past 50 y, provided a robust framework for developing radiological protection policy, regulation, and application. It has, however, been evolving as a result of experience with its implementation, modernization of social awareness of a shrinking world where the Internet links everyone instantly, and increasing public interest in safety-related decisions. These currents have gently pushed the ICRP in recent years to focus more sharply on particular aspects of its system: optimization, prevailing circumstances, the use of effective dose and aspects of an individual's risk, and consideration of the independent implementation of the international system's elements. This paper will present these issues and their relevance to the ICRP system of protection and its evolution. The broader framework of radiological protection (e.g., science, philosophy, policy, regulation, implementation), of which the ICRP is an important element, will provide a global, equally evolving context for this characterization of the changing ICRP system of radiological protection.

The recommendations of ICRP Publication 111 in the light of the ICRP dialogue initiative in Fukushima.

PubMed

Lochard, J

2016-12-01

Publication 111, published by the International Commission on Radiological Protection (ICRP) in 2009, provided the first recommendations for dealing with the long-term recovery phase after a nuclear accident. Its focus is on the protection of people living in long-term contaminated areas after a nuclear accident, drawing on the experience of the Belarus population, Cumbrian sheep farmers in the UK, and Sami reindeer herders in Norway affected by the fallout from Chernobyl. The ICRP dialogue initiative in Fukushima confirmed what had been identified after Chernobyl, namely the very strong concern for health, particularly that of children, loss of control over everyday life, apprehension about the future, disintegration of family life and of the social and economic fabric, and the threat to the autonomy and dignity of affected people. Through their testimonies and reflections, the participants of the 12 dialogue meetings shed light on this complex situation. The ICRP dialogue initiative also confirmed that the wellbeing of the affected people is at stake, and radiological protection must focus on rehabilitation of their living conditions. The challenge is to incorporate the important clarifications resulting from the ICRP dialogue initiative into the updated version of Publication 111 that is currently in development. This paper does not necessarily reflect the views of the International Commission on Radiological Protection.

FASH and MASH: female and male adult human phantoms based on polygon mesh surfaces: I. Development of the anatomy

NASA Astrophysics Data System (ADS)

Cassola, V. F.; de Melo Lima, V. J.; Kramer, R.; Khoury, H. J.

2010-01-01

Among computational models, voxel phantoms based on computer tomographic (CT), nuclear magnetic resonance (NMR) or colour photographic images of patients, volunteers or cadavers have become popular in recent years. Although being true to nature representations of scanned individuals, voxel phantoms have limitations, especially when walled organs have to be segmented or when volumes of organs or body tissues, like adipose, have to be changed. Additionally, the scanning of patients or volunteers is usually made in supine position, which causes a shift of internal organs towards the ribcage, a compression of the lungs and a reduction of the sagittal diameter especially in the abdominal region compared to the regular anatomy of a person in the upright position, which in turn can influence organ and tissue absorbed or equivalent dose estimates. This study applies tools developed recently in the areas of computer graphics and animated films to the creation and modelling of 3D human organs, tissues, skeletons and bodies based on polygon mesh surfaces. Female and male adult human phantoms, called FASH (Female Adult meSH) and MASH (Male Adult meSH), have been designed using software, such as MakeHuman, Blender, Binvox and ImageJ, based on anatomical atlases, observing at the same time organ masses recommended by the International Commission on Radiological Protection for the male and female reference adult in report no 89. 113 organs, bones and tissues have been modelled in the FASH and the MASH phantoms representing locations for adults in standing posture. Most organ and tissue masses of the voxelized versions agree with corresponding data from ICRP89 within a margin of 2.6%. Comparison with the mesh-based male RPI_AM and female RPI_AF phantoms shows differences with respect to the material used, to the software and concepts applied, and to the anatomies created.

Current activities in the ICRP concerning estimation of radiation doses to patients from radiopharmaceuticals for diagnostic use

NASA Astrophysics Data System (ADS)

Mattsson, S.; Johansson, L.; Leide-Svegborn, S.; Liniecki, J.; Nosske, D.; Riklund, K.; Stabin, M.; Taylor, D.

2011-09-01

A Task Group within the ICRP Committees 2 and 3 is continuously working to improve absorbed dose estimates to patients investigated with radiopharmaceuticals. The work deals with reviews of the literature, initiation of new or complementary studies of the biokinetics of a compound and dose estimates. Absorbed dose calculations for organs and tissues have up to now been carried out using the MIRD formalism. There is still a lack of necessary biokinetic data from measurements in humans. More time series obtained by nuclear medicine imaging techniques such as whole-body planar gamma-camera imaging, SPECT or PET are highly desirable for this purpose. In 2008, a new addendum to ICRP Publication 53 was published under the name of ICRP Publication 106 containing biokinetic data and absorbed dose information to organs and tissues of patients of various ages for radiopharmaceuticals in common use. That report also covers a number of generic models and realistic maximum models covering other large groups of substances (e.g. "123I-brain receptor substances"). Together with ICRP Publication 80, most radiopharmaceuticals in clinical use at the time of publication were covered except the radioiodine labeled compounds for which the ICRP dose estimates are still found in Publication 53. There is an increasing use of new radiopharmaceuticals, especially PET-tracers and the TG has recently finished its work with biokinetic and dosimetric data for 18F-FET, 18F-FLT and 18F-choline. The work continues now with new data for 11C-raclopride, 11C-PiB and 123I-ioflupan as well as re-evaluation of published data for 82Rb-chloride, 18F-fluoride and radioiodide. This paper summarises published ICRP-information on dose to patients from radiopharmaceuticals and gives some preliminary data for substances under review.

Application of the Commission's recommendations: the 2013-2017 Committee 4 programme of work.

PubMed

Lochard, J

2015-06-01

Committee 4 of the International Commission on Radiological Protection (ICRP) is responsible for developing principles, recommendations, and guidance on the protection of people against radiation exposure, and to consider their practical application in all exposure situations. Currently, the Committee's efforts are focused on the completion of a series of future ICRP publications on the implementation of its 2007 Recommendations to the various existing exposure situations. A report on protection against radon exposure was published recently (ICRP Publication 126), and two documents on protection against cosmic radiation in aviation, and naturally occurring radioactive material are under development. The programme of work for the forthcoming 2013-2017 period comprises the update of ICRP Publication 109 on protection of people in emergency exposure situations, and the update of ICRP Publication 111 on protection of people living in long-term contaminated areas after a nuclear accident, as well as the development of a future ICRP publication on the ethics of radiological protection. It also includes the preparation of task groups on the application of the Commission's recommendations for contaminated sites from past activities and for surface and near-surface disposal of radioactive waste. Another important task for Committee 4 will be to develop a reflection on the tolerability of risk from radiation. © The International Society for Prosthetics and Orthotics Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

ICRP - What's happening

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meinhold, C.B.

1982-01-01

This paper discusses the goals of the ICRP for the 1980 decade in optimizing radiation protection in the areas of workers, patients, and the public. Economic and operational concerns are expressed. (PSB)

Specific absorbed fractions of electrons and photons for Rad-HUMAN phantom using Monte Carlo method

NASA Astrophysics Data System (ADS)

Wang, Wen; Cheng, Meng-Yun; Long, Peng-Cheng; Hu, Li-Qin

2015-07-01

The specific absorbed fractions (SAF) for self- and cross-irradiation are effective tools for the internal dose estimation of inhalation and ingestion intakes of radionuclides. A set of SAFs of photons and electrons were calculated using the Rad-HUMAN phantom, which is a computational voxel phantom of a Chinese adult female that was created using the color photographic image of the Chinese Visible Human (CVH) data set by the FDS Team. The model can represent most Chinese adult female anatomical characteristics and can be taken as an individual phantom to investigate the difference of internal dose with Caucasians. In this study, the emission of mono-energetic photons and electrons of 10 keV to 4 MeV energy were calculated using the Monte Carlo particle transport calculation code MCNP. Results were compared with the values from ICRP reference and ORNL models. The results showed that SAF from the Rad-HUMAN have similar trends but are larger than those from the other two models. The differences were due to the racial and anatomical differences in organ mass and inter-organ distance. The SAFs based on the Rad-HUMAN phantom provide an accurate and reliable data for internal radiation dose calculations for Chinese females. Supported by Strategic Priority Research Program of Chinese Academy of Sciences (XDA03040000), National Natural Science Foundation of China (910266004, 11305205, 11305203) and National Special Program for ITER (2014GB112001)

The computation of ICRP dose coefficients for intakes of radionuclides with PLEIADES: biokinetic aspects.

PubMed

Fell, T P

2007-01-01

The ICRP has published dose coefficients for the ingestion or inhalation of radionuclides in a series of reports covering intakes by workers and members of the public including children and pregnant or lactating women. The calculation of these coefficients conveniently divides into two distinct parts--the biokinetic and dosimetric. This paper gives a brief summary of the methods used to solve the biokinetic problem in the generation of dose coefficients on behalf of the ICRP, as implemented in the Health Protection Agency's internal dosimetry code PLEIADES.

WORKER INHALATION DOSE COEFFICIENTS FOR RADIONUCLIDES NOT PREVIOUSLY IDENTIFIED IN ICRP PUBLICATION 68

DOE Office of Scientific and Technical Information (OSTI.GOV)

McLaughlin, David A; Schwahn, Scott O

2011-01-01

While inhalation dose coefficients are provided for about 800 radionuclides in International Commission on Radiological Protection (ICRP) Publication 68, many radionuclides of practical dosimetric interest for facilities such as high-energy proton accelerators are not specifically addressed, nor are organ-specific dose coefficients tabulated. The ICRP Publication 68 methodology is used, along with updated radiological decay data and metabolic data, to identify committed equivalent dose coefficients [hT(50)] and committed effective dose coefficients [e(50)] for radionuclides produced at the Oak Ridge National Laboratory s Spallation Neutron Source.

Hybrid computational phantoms of the 15-year male and female adolescent: Applications to CT organ dosimetry for patients of variable morphometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Choonsik; Lodwick, Daniel; Williams, Jonathan L.

Currently, two classes of the computational phantoms have been developed for dosimetry calculation: (1) stylized (or mathematical) and (2) voxel (or tomographic) phantoms describing human anatomy through mathematical surface equations and three-dimensional labeled voxel matrices, respectively. Mathematical surface equations in stylized phantoms provide flexibility in phantom design and alteration, but the resulting anatomical description is, in many cases, not very realistic. Voxel phantoms display far better anatomical realism, but they are limited in terms of their ability to alter organ shape, position, and depth, as well as body posture. A new class of computational phantoms - called hybrid phantoms -more » takes advantage of the best features of stylized and voxel phantoms - flexibility and anatomical realism, respectively. In the current study, hybrid computational phantoms representing reference 15-year male and female body anatomy and anthropometry are presented. For the male phantom, organ contours were extracted from the University of Florida (UF) 14-year series B male voxel phantom, while for the female phantom, original computed tomography (CT) data from two 14-year female patients were used. Polygon mesh models for the major organs and tissues were reconstructed for nonuniform rational B-spline (NURBS) surface modeling. The resulting NURBS/polygon mesh models representing body contour and internal anatomy were matched to anthropometric data and reference organ mass data provided by the Centers for Disease Control and Prevention (CDC) and the International Commission on Radiation Protection (ICRP), respectively. Finally, two hybrid 15-year male and female phantoms were completed where a total of eight anthropometric data categories were matched to standard values within 4% and organ masses matched to ICRP data within 1% with the exception of total skin. To highlight the flexibility of the hybrid phantoms, 10th and 90th weight percentile 15-year male and female phantoms were further developed from the 50th percentile phantoms through adjustments in the body contour to match the total body masses given in CDC pediatric growth curves. The resulting six NURBS phantoms, male and female phantoms representing their 10th, 50th, and 90th weight percentiles, were used to investigate the influence of body fat distributions on internal organ doses following CT imaging. The phantoms were exposed to multislice chest and abdomen helical CT scans, and in-field organ absorbed doses were calculated. The results demonstrated that the use of traditional stylized phantoms yielded organ dose estimates that deviate from those given by the UF reference hybrid phantoms by up to a factor of 2. The study also showed that use of reference, or 50th percentile, phantoms to assess organ doses in underweight 15-year-old children would not lead to significant organ dose errors (typically less than 10%). However, more significant errors were noted (up to {approx}30%) when reference phantoms are used to represent overweight children in CT imaging dosimetry. These errors are expected to only further increase as one considers CT organ doses in overweight and obese individuals of the adult patient population, thus emphasizing the advantages of patient-sculptable phantom technology.« less

Radiological protection from radioactive waste management in existing exposure situations resulting from a nuclear accident.

PubMed

Sugiyama, Daisuke; Hattori, Takatoshi

2013-01-01

In environmental remediation after nuclear accidents, radioactive wastes have to be appropriately managed in existing exposure situations with contamination resulting from the emission of radionuclides by such accidents. In this paper, a framework of radiation protection from radioactive waste management in existing exposure situations for application to the practical and reasonable waste management in contaminated areas, referring to related ICRP recommendations was proposed. In the proposed concept, intermediate reference levels for waste management are adopted gradually according to the progress of the reduction in the existing ambient dose in the environment on the basis of the principles of justification and optimisation by taking into account the practicability of the management of radioactive waste and environmental remediation. It is essential to include the participation of relevant stakeholders living in existing exposure situations in the selection of reference levels for the existing ambient dose and waste management.

Radiological protection from radioactive waste management in existing exposure situations resulting from a nuclear accident

PubMed Central

Sugiyama, Daisuke; Hattori, Takatoshi

2013-01-01

In environmental remediation after nuclear accidents, radioactive wastes have to be appropriately managed in existing exposure situations with contamination resulting from the emission of radionuclides by such accidents. In this paper, a framework of radiation protection from radioactive waste management in existing exposure situations for application to the practical and reasonable waste management in contaminated areas, referring to related ICRP recommendations was proposed. In the proposed concept, intermediate reference levels for waste management are adopted gradually according to the progress of the reduction in the existing ambient dose in the environment on the basis of the principles of justification and optimisation by taking into account the practicability of the management of radioactive waste and environmental remediation. It is essential to include the participation of relevant stakeholders living in existing exposure situations in the selection of reference levels for the existing ambient dose and waste management. PMID:22719047

Comparative analysis of dosimetry parameters for nuclear medicine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Toohey, R.E.; Stabin, M.G.

For years many have employed the concept of ``total-body dose`` or ``whole-body dose,`` i.e., the total energy deposited in the body divided by the mass of the body, when evaluating the risks of different nuclear medicine procedures. The effective dose equivalent (H{sub E}), first described in ICRP Publication 26, has been accepted by some as a better quantity to use in evaluating the total risk of a procedure, but its use has been criticized by others primarily because the tissue weighting factors were intended for use in the radiation worker, rather than the nuclear medicine patient population. Nevertheless, in ICRPmore » Publication 52, the ICRP has suggested that the H{sub E} may be used in nuclear medicine. The ICRP also has published a compendium of dose estimates, including H{sub E} values, for various nuclear medicine procedures at various ages in ICRP Publication 53. The effective dose (E) of ICRP Publication 60 is perhaps more suitable for use in nuclear medicine, with tissue weighting factors based on the entire population. Other comparisons of H{sub E} and E have been published. The authors have used the program MIRDOSE 3.1 to compute total-body dose, H{sub E}, and E for 62 radiopharmaceutical procedures, based on the best current biokinetic data available.« less

Radiation Dosimetry of Whole-Body Dual-Tracer 18F-FDG and 11C-Acetate PET/CT for Hepatocellular Carcinoma.

PubMed

Liu, Dan; Khong, Pek-Lan; Gao, Yiming; Mahmood, Usman; Quinn, Brian; St Germain, Jean; Xu, X George; Dauer, Lawrence T

2016-06-01

Combined whole-body dual-tracer ((18)F-FDG and (11)C-acetate) PET/CT is increasingly used for staging hepatocellular carcinoma, with only limited studies investigating the radiation dosimetry data of these scans. The aim of the study was to characterize the radiation dosimetry of combined whole-body dual-tracer PET/CT protocols. Consecutive adult patients with hepatocellular carcinoma who underwent whole-body dual-tracer PET/CT scans were retrospectively reviewed with institutional review board approval. OLINDA/EXM 1.1 was used to estimate patient-specific internal dose exposure in each organ. Biokinetic models for (18)F-FDG and (11)C-acetate as provided by ICRP (International Commission on Radiological Protection) publication 106 were used. Standard reference phantoms were modified to more closely represent patient-specific organ mass. With patient-specific parameters, organ equivalent doses from each CT series were estimated using VirtualDose. Dosimetry capabilities for tube current modulation protocols were applied by integrating with the latest anatomic realistic models. Effective dose was calculated using ICRP publication 103 tissue-weighting coefficients for adult male and female, respectively. Fourteen scans were evaluated (12 men, 2 women; mean age ± SD, 60 ± 19.48 y). The patient-specific effective dose from (18)F-FDG and (11)C-acetate was 6.08 ± 1.49 and 1.56 ± 0.47 mSv, respectively, for male patients and 6.62 ± 1.38 and 1.79 ± 0.12 mSV, respectively, for female patients. The patient-specific effective dose of the CT component, which comprised 2 noncontrast whole-body scans, to male and female patients was 21.20 ± 8.94 and 14.79 ± 3.35 mSv, respectively. Thus, the total effective doses of the combined whole-body dual-tracer PET/CT studies for male and female patients were 28.84 ± 10.18 and 23.19 ± 4.61 mSv, respectively. Patient-specific parameters allow for more accurate estimation of organ equivalent doses. Considering the substantial radiation dose incurred, judicious medical justification is required with every whole-body dual-tracer PET/CT referral. Although radiation risks may have less impact for the population with cancer because of their reduced life expectancy, the information is of interest and relevant for both justification, to evaluate risk/benefit, and protocol optimization. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Measurements of indoor 222RN activity in dwellings and workplaces of Curitiba (Brazil)

NASA Astrophysics Data System (ADS)

Corrêa, Janine N.; Paschuk, Sergei A.; Del Claro, Flávia; Kappke, Jaqueline; Perna, Allan F. N.; Schelin, Hugo R.; Denyak, Valeriy

2014-11-01

The present work describes the results of systematic measurements of radon (222Rn) in residential environments and workplaces in the Metropolitan Region of Curitiba (Paraná State, Brazil) during the period 2004-2012. For radon in air activity measurements, polycarbonate Track Etch Detectors CR-39, mounted in diffusion chambers protected by borosilicate glass fiber filters, were used. After being exposed in air, the CR-39 detectors were submitted to a chemical etching in a 6.25 M NaOH solution at 70 °C for 14 h. The alpha particle tracks were identified and manually counted with an optical microscope, and with the results of previously performed calibrations, the indoor activity concentration of 222Rn was calculated. The calibration of CR-39 and the alpha particle tracks chemical development procedures were performed in collaboration the National Institute of Radiological Sciences (NIRS, Japan). The major part of indoor 222Rn concentration in residences was found to be below 100 Bq/m3. In the case of working places, all measurements of 222Rn concentrations were below 100 Bq/m3. These values are considered within the limits set by international regulatory agencies, such as the US EPA and ICRP, which adopt up to 148 and 300 Bq/m3 as upper values for the reference levels for radon gas activity in dwellings, respectively. The latest value of 300 Bq/m3 for radon activity in air is proposed by ICRP considering the upper value for the individual dose reference level for radon exposure of 10 mSv/yr.

TU-F-CAMPUS-I-01: Investigation of the Effective Dose From Bolus Tracking Acquisitions at Different Anatomical Locations in the Chest for CT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nowik, P; Bujila, R; Merzan, D

2015-06-15

Purpose: Stationary table acquisitions (Bolus tracking) in X-ray Computed Tomography (CT) can Result in dose length products (DLP) comparable to spiral scans. It is today unclear whether or not the effective dose (E) for Bolus Tracking can be approximated using target region specific conversion factors (E/DLP). The purpose of this study was to investigate how E depends on the anatomical location of the Bolus Tracking in relation to Chest CT scans with the same DLP. Methods: Effective doses were approximated for the ICRP 110 adult Reference Male (AM) and adult Reference Female (FM) computational voxel phantoms using software for CTmore » dose approximations (pre-simulated MC data). The effective dose was first approximated for a Chest CT scan using spiral technique and a CTDIvol (32 cm) of 6 mGy. The effective dose from the spiral scan was then compared to E approximated for contiguous Bolus Tracking acquisitions (1 cm separation), with a total collimation of 1 cm, over different locations of the chest of the voxel phantoms. The number of rotations used for the Bolus Tracking acquisitions was adjusted to yield the same DLP (32 cm) as the spiral scan. Results: Depending on the anatomical location of the Bolus Tracking, E ranged by factors of 1.3 to 6.8 for the AM phantom and 1.4 to 3.3 for the AF phantom, compared to the effective dose of the spiral scans. The greatest E for the Bolus Tracking acquisitions was observed for anatomical locations coinciding with breast tissue. This can be expected as breast tissue has a high tissue weighting factor in the calculation of E. Conclusion: For Chest CT scans, the effective dose from Bolus Tracking is highly dependent on the anatomical location where the scan is administered and will not always accurately be represented using target region specific conversion factors.« less

Patient-specific radiation dose and cancer risk estimation in CT: Part II. Application to patients

PubMed Central

Li, Xiang; Samei, Ehsan; Segars, W. Paul; Sturgeon, Gregory M.; Colsher, James G.; Toncheva, Greta; Yoshizumi, Terry T.; Frush, Donald P.

2011-01-01

Purpose: Current methods for estimating and reporting radiation dose from CT examinations are largely patient-generic; the body size and hence dose variation from patient to patient is not reflected. Furthermore, the current protocol designs rely on dose as a surrogate for the risk of cancer incidence, neglecting the strong dependence of risk on age and gender. The purpose of this study was to develop a method for estimating patient-specific radiation dose and cancer risk from CT examinations. Methods: The study included two patients (a 5-week-old female patient and a 12-year-old male patient), who underwent 64-slice CT examinations (LightSpeed VCT, GE Healthcare) of the chest, abdomen, and pelvis at our institution in 2006. For each patient, a nonuniform rational B-spine (NURBS) based full-body computer model was created based on the patient’s clinical CT data. Large organs and structures inside the image volume were individually segmented and modeled. Other organs were created by transforming an existing adult male or female full-body computer model (developed from visible human data) to match the framework defined by the segmented organs, referencing the organ volume and anthropometry data in ICRP Publication 89. A Monte Carlo program previously developed and validated for dose simulation on the LightSpeed VCT scanner was used to estimate patient-specific organ dose, from which effective dose and risks of cancer incidence were derived. Patient-specific organ dose and effective dose were compared with patient-generic CT dose quantities in current clinical use: the volume-weighted CT dose index (CTDIvol) and the effective dose derived from the dose-length product (DLP). Results: The effective dose for the CT examination of the newborn patient (5.7 mSv) was higher but comparable to that for the CT examination of the teenager patient (4.9 mSv) due to the size-based clinical CT protocols at our institution, which employ lower scan techniques for smaller patients. However, the overall risk of cancer incidence attributable to the CT examination was much higher for the newborn (2.4 in 1000) than for the teenager (0.7 in 1000). For the two pediatric-aged patients in our study, CTDIvol underestimated dose to large organs in the scan coverage by 30%–48%. The effective dose derived from DLP using published conversion coefficients differed from that calculated using patient-specific organ dose values by −57% to 13%, when the tissue weighting factors of ICRP 60 were used, and by −63% to 28%, when the tissue weighting factors of ICRP 103 were used. Conclusions: It is possible to estimate patient-specific radiation dose and cancer risk from CT examinations by combining a validated Monte Carlo program with patient-specific anatomical models that are derived from the patients’ clinical CT data and supplemented by transformed models of reference adults. With the construction of a large library of patient-specific computer models encompassing patients of all ages and weight percentiles, dose and risk can be estimated for any patient prior to or after a CT examination. Such information may aid in decisions for image utilization and can further guide the design and optimization of CT technologies and scan protocols. PMID:21361209

Patient-specific radiation dose and cancer risk estimation in CT: Part II. Application to patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

2011-01-15

Purpose: Current methods for estimating and reporting radiation dose from CT examinations are largely patient-generic; the body size and hence dose variation from patient to patient is not reflected. Furthermore, the current protocol designs rely on dose as a surrogate for the risk of cancer incidence, neglecting the strong dependence of risk on age and gender. The purpose of this study was to develop a method for estimating patient-specific radiation dose and cancer risk from CT examinations. Methods: The study included two patients (a 5-week-old female patient and a 12-year-old male patient), who underwent 64-slice CT examinations (LightSpeed VCT, GEmore » Healthcare) of the chest, abdomen, and pelvis at our institution in 2006. For each patient, a nonuniform rational B-spine (NURBS) based full-body computer model was created based on the patient's clinical CT data. Large organs and structures inside the image volume were individually segmented and modeled. Other organs were created by transforming an existing adult male or female full-body computer model (developed from visible human data) to match the framework defined by the segmented organs, referencing the organ volume and anthropometry data in ICRP Publication 89. A Monte Carlo program previously developed and validated for dose simulation on the LightSpeed VCT scanner was used to estimate patient-specific organ dose, from which effective dose and risks of cancer incidence were derived. Patient-specific organ dose and effective dose were compared with patient-generic CT dose quantities in current clinical use: the volume-weighted CT dose index (CTDI{sub vol}) and the effective dose derived from the dose-length product (DLP). Results: The effective dose for the CT examination of the newborn patient (5.7 mSv) was higher but comparable to that for the CT examination of the teenager patient (4.9 mSv) due to the size-based clinical CT protocols at our institution, which employ lower scan techniques for smaller patients. However, the overall risk of cancer incidence attributable to the CT examination was much higher for the newborn (2.4 in 1000) than for the teenager (0.7 in 1000). For the two pediatric-aged patients in our study, CTDI{sub vol} underestimated dose to large organs in the scan coverage by 30%-48%. The effective dose derived from DLP using published conversion coefficients differed from that calculated using patient-specific organ dose values by -57% to 13%, when the tissue weighting factors of ICRP 60 were used, and by -63% to 28%, when the tissue weighting factors of ICRP 103 were used. Conclusions: It is possible to estimate patient-specific radiation dose and cancer risk from CT examinations by combining a validated Monte Carlo program with patient-specific anatomical models that are derived from the patients' clinical CT data and supplemented by transformed models of reference adults. With the construction of a large library of patient-specific computer models encompassing patients of all ages and weight percentiles, dose and risk can be estimated for any patient prior to or after a CT examination. Such information may aid in decisions for image utilization and can further guide the design and optimization of CT technologies and scan protocols.« less

Involving stakeholders in radiological protection decision making: recovery history and lessons from the people of Fukushima.

PubMed

Lazo, T

2016-12-01

Between September 2011 and August 2015, the International Commission on Radiological Protection (ICRP) organised a series of 12 stakeholder dialogue workshops with residents of Fukushima Prefecture. Discussions focused on recovery, addressing topics such as protection of children, management of contaminated food, monitoring, and self-help measures. The OECD Nuclear Energy Agency (NEA) supported, and the Committee on Radiation Protection and Public Health (CRPPH) Secretariat attended, all 12 meetings to listen directly to the concerns of affected individuals and draw lessons for CRPPH. To summarise the dialogue results, ICRP organised a final meeting in Date, Japan with the support of NEA and other organisations. The lessons from and utility of the dialogue meetings were praised by dialogue participants and sponsors, and ICRP agreed that some form of dialogue would continue, although with ICRP participation and support rather than leadership. This paper summarises the internationally relevant lessons learned by CRPPH from this important process.

Effective radiation dose of ProMax 3D cone-beam computerized tomography scanner with different dental protocols.

PubMed

Qu, Xing-min; Li, Gang; Ludlow, John B; Zhang, Zu-yan; Ma, Xu-chen

2010-12-01

The aim of this study was to compare effective doses resulting from different scan protocols for cone-beam computerized tomography (CBCT) using International Commission on Radiological Protection (ICRP) 1990 and 2007 calculations of dose. Average tissue-absorbed dose, equivalent dose, and effective dose for a ProMax 3D CBCT with different dental protocols were calculated using thermoluminescent dosimeter chips in a human equivalent phantom. Effective doses were derived using ICRP 1990 and the superseding 2007 recommendations. Effective doses (ICRP 2007) for default patient sizes from small to large ranged from 102 to 298 μSv. The coefficient of determination (R(2)) between tube current and effective dose (ICRP 2007) was 0.90. When scanning with lower resolution settings, the effective doses were reduced significantly (P < .05). ProMax 3D can provide a wide range of radiation dose levels. Reduction in radiation dose can be achieved when using lower settings of exposure parameters. Copyright © 2010 Mosby, Inc. All rights reserved.

Relationships (I) of International Classification of High-resolution Computed Tomography for Occupational and Environmental Respiratory Diseases with the ILO International Classification of Radiographs of Pneumoconioses for parenchymal abnormalities.

PubMed

Tamura, Taro; Suganuma, Narufumi; Hering, Kurt G; Vehmas, Tapio; Itoh, Harumi; Akira, Masanori; Takashima, Yoshihiro; Hirano, Harukazu; Kusaka, Yukinori

2015-01-01

The International Classification of High-resolution Computed Tomography (HRCT) for Occupational and Environmental Respiratory Diseases (ICOERD) has been developed for the screening, diagnosis, and epidemiological reporting of respiratory diseases caused by occupational hazards. This study aimed to establish a correlation between readings of HRCT (according to the ICOERD) and those of chest radiography (CXR) pneumoconiotic parenchymal opacities (according to the International Labor Organization Classification/International Classification of Radiographs of Pneumoconioses [ILO/ICRP]). Forty-six patients with and 28 controls without mineral dust exposure underwent posterior-anterior CXR and HRCT. We recorded all subjects' exposure and smoking history. Experts independently read CXRs (using ILO/ICRP). Experts independently assessed HRCT using the ICOERD parenchymal abnormalities grades for well-defined rounded opacities (RO), linear and/or irregular opacities (IR), and emphysema (EM). The correlation between the ICOERD summed grades and ILO/ICRP profusions was evaluated using Spearman's rank-order correlation. Twenty-three patients had small opacities on CXR. HRCT showed that 21 patients had RO; 20 patients, IR opacities; and 23 patients, EM. The correlation between ILO/ICRP profusions and the ICOERD grades was 0.844 for rounded opacities (p<0.01). ICOERD readings from HRCT scans correlated well with previously validated ILO/ICRP criteria. The ICOERD adequately detects pneumoconiotic micronodules and can be used for the interpretation of pneumoconiosis.

The internal dosimetry of Rubidium-82 based on dynamic PET/CT imaging in humans

NASA Astrophysics Data System (ADS)

Hunter, Chad R.

Rubidium-82 (Rb-82) is a useful blood flow tracer, and has become important in recent years due to the shutdown of the Chalk River reactor. Published effective dose estimates for Rb-82 vary widely, and as yet no comprehensive study in man has been conducted with PET/CT, and no effective dose estimates for Rb-82 during pharmacological stress testing has been published. 30 subjects were recruited for rest, and 25 subjects were recruited for stress. The subjects consisted of both cardiac patients and normal subjects. For rest, a total of 283 organs were measured across 60 scans. For stress, a total of 171 organs were measured across 25 scans. Effective dose estimates were calculated using the ICRP 60, 80, and 103 tissue weighting factors. Relative differences between this study and the published in-vivo estimates showed agreement for the lungs. Relative differences between this study and the blood flow models showed differences> 5 times in the thyroid contribution to the effective dose demonstrating a limitation in these models. Comparisons between rest and stress effective dose estimates revealed no significant difference. The average 'adult' effective dose for Rb-82 was found to be 0.00084+/-0.00018 mSv/MBq. The highest dose organs were the lungs, kidneys and stomach wall. These dose estimates for Rb-82 are the first to be measured directly with PET/CT in humans, and are 4 times lower than previous ICRP 60 values based on a theoretical blood flow model. The total adult effective dose from a typical Rb-82 study including CT for attenuation correction and potential Sr-85 breakthrough is 1.5 +/- 0.4 mSv.

Radiation absorbed dose estimates for 18F-BPA PET.

PubMed

Kono, Yuzuru; Kurihara, Hiroaki; Kawamoto, Hiroshi; Yasui, Naoko; Honda, Naoki; Igaki, Hiroshi; Itami, Jun

2017-09-01

Background Boron neutron capture therapy (BNCT) is a molecular radiation therapy approach based on the 10 B (n, α) 7 Li nuclear reaction in cancer cells. In BNCT, delivery of 10 B in the form of 4-borono-phenylalanine conjugated with fructose (BPA-fr) to the cancer cells is important. The PET tracer 4-borono-2-18F-fluoro-phenylalanine (FBPA) has been used to predict the accumulation of BPA-fr before BNCT. Purpose To determine the biodistribution and dosimetric parameters in 18F-BPA PET/CT studies. Material and Methods Human biokinetic data were obtained during clinical 18F-BPA PET studies between February and June 2015 at one institution. Nine consecutive patients were studied prospectively. The internal radiation dose was calculated on the basis of radioactivity data from blood, urine, and normal tissue of the heart, liver, spleen, kidney, and other parts of the body at each time point using OLINDA/EXM1.1 program. We compared our calculations with published 18F-FDG data. Results Adult patients (3 men, 3 women; age range, 28-68 years) had significantly smaller absorbed doses than pediatric patients (3 patients; age range, 5-12 years) ( P = 0.003). The mean effective dose was 57% lower in adult patients compared with pediatric patients. Mean effective doses for 18F-BPA were 25% lower than those for 18F-FDG presented in International Commission of Radiation Protection (ICRP) publication 106. Conclusion We found significant differences in organ absorbed doses for 18F-BPA against those for 18F-FDG presented in ICRP publication 106. Mean effective doses for 18F-BPA were smaller than those for 18F-FDG in the publication by 0.5-38% (mean difference, 25%).

Estimates of internal-dose equivalent from inhalation and ingestion of selected radionuclides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dunning, D.E.

1982-01-01

This report presents internal radiation dose conversion factors for radionuclides of interest in environmental assessments of nuclear fuel cycles. This volume provides an updated summary of estimates of committed dose equivalent for radionuclides considered in three previous Oak Ridge National Laboratory (ORNL) reports. Intakes by inhalation and ingestion are considered. The International Commission on Radiological Protection (ICRP) Task Group Lung Model has been used to simulate the deposition and retention of particulate matter in the respiratory tract. Results corresponding to activity median aerodynamic diameters (AMAD) of 0.3, 1.0, and 5.0 ..mu..m are given. The gastorintestinal (GI) tract has been representedmore » by a four-segment catenary model with exponential transfer of radioactivity from one segment to the next. Retention of radionuclides in systemic organs is characterized by linear combinations of decaying exponential functions, recommended in ICRP Publication 30. The first-year annual dose rate, maximum annual dose rate, and fifty-year dose commitment per microcurie intake of each radionuclide is given for selected target organs and the effective dose equivalent. These estimates include contributions from specified source organs plus the systemic activity residing in the rest of the body; cross irradiation due to penetrating radiations has been incorporated into these estimates. 15 references.« less

A DISCUSSION ON DIFFERENT APPROACHES FOR ASSESSING LIFETIME RISKS OF RADON-INDUCED LUNG CANCER.

PubMed

Chen, Jing; Murith, Christophe; Palacios, Martha; Wang, Chunhong; Liu, Senlin

2017-11-01

Lifetime risks of radon induced lung cancer were assessed based on epidemiological approaches for Canadian, Swiss and Chinese populations, using the most recent vital statistic data and radon distribution characteristics available for each country. In the risk calculation, the North America residential radon risk model was used for the Canadian population, the European residential radon risk model for the Swiss population, the Chinese residential radon risk model for the Chinese population, and the EPA/BEIR-VI radon risk model for all three populations. The results were compared with the risk calculated from the International Commission on Radiological Protection (ICRP)'s exposure-to-risk conversion coefficients. In view of the fact that the ICRP coefficients were recommended for radiation protection of all populations, it was concluded that, generally speaking, lifetime absolute risks calculated with ICRP-recommended coefficients agree reasonably well with the range of radon induced lung cancer risk predicted by risk models derived from epidemiological pooling analyses. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Dose conversion coefficients based on the Chinese mathematical phantom and MCNP code for external photon irradiation.

PubMed

Qiu, Rui; Li, Junli; Zhang, Zhan; Liu, Liye; Bi, Lei; Ren, Li

2009-02-01

A set of conversion coefficients from kerma free-in-air to the organ-absorbed dose are presented for external monoenergetic photon beams from 10 keV to 10 MeV based on the Chinese mathematical phantom, a whole-body mathematical phantom model. The model was developed based on the methods of the Oak Ridge National Laboratory mathematical phantom series and data from the Chinese Reference Man and the Reference Asian Man. This work is carried out to obtain the conversion coefficients based on this model, which represents the characteristics of the Chinese population, as the anatomical parameters of the Chinese are different from those of Caucasians. Monte Carlo simulation with MCNP code is carried out to calculate the organ dose conversion coefficients. Before the calculation, the effects from the physics model and tally type are investigated, considering both the calculation efficiency and precision. In the calculation irradiation conditions include anterior-posterior, posterior-anterior, right lateral, left lateral, rotational and isotropic geometries. Conversion coefficients from this study are compared with those recommended in the Publication 74 of International Commission on Radiological Protection (ICRP74) since both the sets of data are calculated with mathematical phantoms. Overall, consistency between the two sets of data is observed and the difference for more than 60% of the data is below 10%. However, significant deviations are also found, mainly for the superficial organs (up to 65.9%) and bone surface (up to 66%). The big difference of the dose conversion coefficients for the superficial organs at high photon energy could be ascribed to kerma approximation for the data in ICRP74. Both anatomical variations between races and the calculation method contribute to the difference of the data for bone surface.

Organ and effective dose rate coefficients for submersion exposure in occupational settings

DOE PAGES

Veinot, K. G.; Y-12 National Security Complex, Oak Ridge, TN; Dewji, S. A.; ...

2017-08-24

External dose coefficients for environmental exposure scenarios are often computed using assumption on infinite or semi-infinite radiation sources. For example, in the case of a person standing on contaminated ground, the source is assumed to be distributed at a given depth (or between various depths) and extending outwards to an essentially infinite distance. In the case of exposure to contaminated air, the person is modeled as standing within a cloud of infinite, or semi-infinite, source distribution. However, these scenarios do not mimic common workplace environments where scatter off walls and ceilings may significantly alter the energy spectrum and dose coefficients.more » In this study, dose rate coefficients were calculated using the International Commission on Radiological Protection (ICRP) reference voxel phantoms positioned in rooms of three sizes representing an office, laboratory, and warehouse. For each room size calculations using the reference phantoms were performed for photons, electrons, and positrons as the source particles to derive mono-energetic dose rate coefficients. Since the voxel phantoms lack the resolution to perform dose calculations at the sensitive depth for the skin, a mathematical phantom was developed and calculations were performed in each room size with the three source particle types. Coefficients for the noble gas radionuclides of ICRP Publication 107 (e.g., Ne, Ar, Kr, Xe, and Rn) were generated by folding the corresponding photon, electron, and positron emissions over the mono-energetic dose rate coefficients. Finally, results indicate that the smaller room sizes have a significant impact on the dose rate per unit air concentration compared to the semi-infinite cloud case. For example, for Kr-85 the warehouse dose rate coefficient is 7% higher than the office dose rate coefficient while it is 71% higher for Xe-133.« less

Organ and effective dose rate coefficients for submersion exposure in occupational settings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Veinot, K. G.; Y-12 National Security Complex, Oak Ridge, TN; Dewji, S. A.

External dose coefficients for environmental exposure scenarios are often computed using assumption on infinite or semi-infinite radiation sources. For example, in the case of a person standing on contaminated ground, the source is assumed to be distributed at a given depth (or between various depths) and extending outwards to an essentially infinite distance. In the case of exposure to contaminated air, the person is modeled as standing within a cloud of infinite, or semi-infinite, source distribution. However, these scenarios do not mimic common workplace environments where scatter off walls and ceilings may significantly alter the energy spectrum and dose coefficients.more » In this study, dose rate coefficients were calculated using the International Commission on Radiological Protection (ICRP) reference voxel phantoms positioned in rooms of three sizes representing an office, laboratory, and warehouse. For each room size calculations using the reference phantoms were performed for photons, electrons, and positrons as the source particles to derive mono-energetic dose rate coefficients. Since the voxel phantoms lack the resolution to perform dose calculations at the sensitive depth for the skin, a mathematical phantom was developed and calculations were performed in each room size with the three source particle types. Coefficients for the noble gas radionuclides of ICRP Publication 107 (e.g., Ne, Ar, Kr, Xe, and Rn) were generated by folding the corresponding photon, electron, and positron emissions over the mono-energetic dose rate coefficients. Finally, results indicate that the smaller room sizes have a significant impact on the dose rate per unit air concentration compared to the semi-infinite cloud case. For example, for Kr-85 the warehouse dose rate coefficient is 7% higher than the office dose rate coefficient while it is 71% higher for Xe-133.« less

Comparison of the mean quality factors for astronauts calculated using the Q-functions proposed by ICRP, ICRU, and NASA

NASA Astrophysics Data System (ADS)

Sato, T.; Endo, A.; Niita, K.

2013-07-01

For the estimation of the radiation risk for astronauts, not only the organ absorbed doses but also their mean quality factors must be evaluated. Three functions have been proposed by different organizations for expressing the radiation quality, including the Q(L), Q(y), and QNASA(Z, E) relationships as defined in International Committee of Radiological Protection (ICRP) Publication 60, International Commission on Radiation Units and Measurements (ICRU) Report 40, and National Aeronautics and Space Administration (NASA) TP-2011-216155, respectively. The Q(L) relationship is the most simple and widely used for space dosimetry, but the use of the latter two functions enables consideration of the difference in the track structure of various charged particles during the risk estimation. Therefore, we calculated the mean quality factors in organs and tissues in ICRP/ICRU reference voxel phantoms for the isotropic exposure to various mono-energetic particles using the three Q-functions. The Particle and Heavy Ion Transport code System PHITS was employed to simulate the particle motions inside the phantoms. The effective dose equivalents and the phantom-averaged effective quality factors for the astronauts were then estimated from the calculated mean quality factors multiplied by the fluence-to-dose conversion coefficients and cosmic-ray fluxes inside a spacecraft. It was found from the calculations that QNASA generally gives the largest values for the phantom-averaged effective quality factors among the three Q-functions for neutron, proton, and lighter-ion irradiation, whereas Q(L) provides the largest values for heavier-ion irradiation. Overall, the introduction of QNASA instead of Q(L) or Q(y) in astronaut dosimetry results in the increase the effective dose equivalents because the majority of the doses are composed of the contributions from protons and neutrons, although this tendency may change by the calculation conditions.

ICRP special radiation protection issues in interventional radiology, digital and cardiac imaging.

PubMed

Vano, E; Faulkner, K

2005-01-01

The International Commission on Radiological Protection (ICRP) has published two reports giving recommendations dealing with the avoidance of deterministic injuries in interventional radiology and the management of patient dose in digital radiology in 2001 and 2004, respectively. Another document, on radiation protection for cardiologists performing fluoroscopically guided procedures, will be produced during 2005. This paper highlights some of the topics of the published reports, their relevance to European legislation on medical exposures and the importance of radiation protection research in underpinning the ICRP task groups' work in to producing these documents. It is also anticipated that the results, obtained in the cardiology work package of the European research project, will be used in the new document on radiation protection for cardiologists.

The Evaluation of the 0.07 and 3 mm Dose Equivalent with a Portable Beta Spectrometer

NASA Astrophysics Data System (ADS)

Hoshi, Katsuya; Yoshida, Tadayoshi; Tsujimura, Norio; Okada, Kazuhiko

Beta spectra of various nuclide species were measured using a commercially available compact spectrometer. The shape of the spectra obtained via the spectrometer was almost similar to that of the theoretical spectra. The beta dose equivalent at any depth was obtained as a product of the measured pulse height spectra and the appropriate conversion coefficients of ICRP Publication 74. The dose rates evaluated from the spectra were comparable with the reference dose rates of standard beta calibration sources. In addition, we were able to determine the dose equivalents with a relative error of indication of 10% without the need for complicated correction.

Report of ICRP Task Group 80: 'radiological protection in geological disposal of long-lived solid radioactive waste'.

PubMed

Weiss, W

2012-01-01

The report of International Commission on Radiological Protection (ICRP) Task Group 80 entitled 'Radiological protection in geological disposal of long-lived solid radioactive waste' updates and consolidates previous ICRP recommendations related to solid waste disposal (ICRP Publications 46, 77, and 81). The recommendations given in this report apply specifically to geological disposal of long-lived solid radioactive waste. The report explains how the 2007 system of radiological protection, described in ICRP Publication 103, can be applied in the context of the geological disposal of long-lived solid radioactive waste. The report is written as a self-standing document. It describes the different stages in the lifetime of a geological disposal facility, and addresses the application of relevant radiological protection principles for each stage depending on the various exposure situations that can be encountered. In particular, the crucial factor that influences application of the protection system over the different phases in the lifetime of a disposal facility is the level of oversight that is present. The level of oversight affects the capability to reduce or avoid exposures. Three main time frames have to be considered for the purpose of radiological protection: time of direct oversight when the disposal facility is being implemented and active oversight is taking place; time of indirect oversight when the disposal facility is sealed and indirect oversight is being exercised to provide additional assurance on behalf of the population; and time of no oversight when oversight is no longer exercised because memory is lost. Copyright © 2012. Published by Elsevier Ltd.

In Vivo Chemoprotective Activity of Bovine Dialyzable Leukocyte Extract in Mouse Bone Marrow Cells against Damage Induced by 5-Fluorouracil

PubMed Central

Coronado-Cerda, Erika Evangelina; Franco-Molina, Moisés Armides; Mendoza-Gamboa, Edgar; Prado-García, Heriberto; Rivera-Morales, Lydia Guadalupe; Zapata-Benavides, Pablo; Rodríguez-Salazar, María del Carmen; Caballero-Hernandez, Diana; Tamez-Guerra, Reyes Silvestre; Rodríguez-Padilla, Cristina

2016-01-01

Chemotherapy treatments induce a number of side effects, such as leukopenia neutropenia, peripheral erythropenia, and thrombocytopenia, affecting the quality of life for cancer patients. 5-Fluorouracil (5-FU) is wieldy used as myeloablative model in mice. The bovine dialyzable leukocyte extract (bDLE) or IMMUNEPOTENT CRP® (ICRP) is an immunomodulatory compound that has antioxidants and anti-inflammatory effects. In order to investigate the chemoprotection effect of ICRP on bone marrow cells in 5-FU treated mice, total bone marrow (BM) cell count, bone marrow colony forming units-granulocyte/macrophage (CFU-GM), cell cycle, immunophenotypification, ROS/superoxide and Nrf2 by flow cytometry, and histological and hematological analyses were performed. Our results demonstrated that ICRP increased BM cell count and CFU-GM number, arrested BM cells in G0/G1 phase, increased the percentage of leukocyte, granulocytic, and erythroid populations, reduced ROS/superoxide formation and Nrf2 activation, and also improved hematological levels and weight gain in 5-FU treated mice. These results suggest that ICRP has a chemoprotective effect against 5-FU in BM cells that can be used in cancer patients. PMID:27191003

Assessment of Dose to the Nursing Infant from Radionuclides in Breast Milk

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leggett, Richard Wayne; Eckerman, Keith F

A computer software package was developed to predict tissue doses to an infant due to intake of radionuclides in breast milk based on bioassay measurements and exposure data for the mother. The package is intended mainly to aid in decisions regarding the safety of breast feeding by a mother who has been acutely exposed to a radionuclide during lactation or pregnancy, but it may be applied to previous intakes during the mother s adult life. The package includes biokinetic and dosimetric information needed to address intake of Co-60, Sr-90, Cs-134, Cs-137, Ir-192, Pu-238, Pu-239, Am-241, or Cf-252 by the mother.more » It has been designed so that the library of biokinetic and dosimetric files can be expanded to address a more comprehensive set of radionuclides without modifying the basic computational module. The methods and models build on the approach used in Publication 95 of the International Commission on Radiological Protection (ICRP 2004), Doses to Infants from Ingestion of Radionuclides in Mothers Milk . The software package allows input of case-specific information or judgments such as chemical form or particle size of an inhaled aerosol. The package is expected to be more suitable than ICRP Publication 95 for dose assessment for real events or realistic planning scenarios in which measurements of the mother s excretion or body burden are available.« less

Internal dosimetry of inhaled iodine-131.

PubMed

Kiani Nasab, Mitra; Rafat Motavalli, Laleh; Miri Hakimabad, Hashem

2018-01-01

In this paper, the dose assessment for the iodine inhalation exposure in 19 aerosol sizes and three gas/vapor forms at three levels of thyroid uptake, was performed. Two different modes of work (light vs. heavy) and breathing (nose vs. mouth) for aerosol inhalation were investigated. In order to calculate the cumulated activities per unit of inhaled activity, a combined model which included the latest models of both human respiratory and alimentary tract was developed. The S values for 131 I were computed based on the ICRP adult male and female reference voxel phantoms by the Monte Carlo method. Then, the committed equivalent and committed effective dose coefficients were obtained (The data are available at http://www.um.ac.ir/∼mirihakim). In general, for the nonzero thyroid uptakes, the maximum cumulated activity was found in the thyroid. When the thyroid is blocked, however, the maximum depends on the work and breathing mode and radioisotope form. Overall, the maximum CED coefficient was evaluated for the inhalation of elemental iodine at thyroid uptake of ∼27% (2.8 × 10 -8 Sv/Bq). As for the particle inhalation per se, mouth breathing of 0.6 nm and 0.2 μm AMTD particles showed to have the maximum (2.8 × 10 -8 Sv/Bq) and minimum (6.4 × 10 -9 Sv/Bq) CED coefficients, respectively. Compared to the reference CED coefficients, the authors found an increase of about 58% for inhalation of the aerosols with AMAD of 1 μm and 70% for 5 μm. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fetal and maternal dose assessment for diagnostic scans during pregnancy

NASA Astrophysics Data System (ADS)

Rafat Motavalli, Laleh; Miri Hakimabad, Hashem; Hoseinian Azghadi, Elie

2016-05-01

Despite the concerns about prenatal exposure to ionizing radiation, the number of nuclear medicine examinations performed for pregnant women increased in the past decade. This study attempts to better quantify radiation doses due to diagnostic nuclear medicine procedures during pregnancy with the help of our recently developed 3, 6, and 9 month pregnant hybrid phantoms. The reference pregnant models represent the adult female international commission on radiological protection (ICRP) reference phantom as a base template with a fetus in her gravid uterus. Six diagnostic scintigraphy scans using different radiopharmaceuticals were selected as typical diagnostic nuclear medicine procedures. Furthermore, the biokinetic data of radioiodine was updated in this study. A compartment representing iodide in fetal thyroid was addressed explicitly in the biokinetic model. Calculations were performed using the Monte Carlo transport method. Tabulated dose coefficients for both maternal and fetal organs are provided. The comparison was made with the previously published fetal doses calculated for stylized pregnant female phantoms. In general, the fetal dose in previous studies suffers from an underestimation of up to 100% compared to fetal dose at organ level in this study. A maximum of difference in dose was observed for the fetal thyroid compared to the previous studies, in which the traditional models did not contain the fetal thyroid. Cumulated activities of major source organs are primarily responsible for the discrepancies in the organ doses. The differences in fetal dose depend on several other factors including chord length distribution between fetal organs and maternal major source organs, and anatomical differences according to gestation periods. Finally, considering the results of this study, which was based on the realistic pregnant female phantoms, a more informed evaluation of the risks and benefits of the different procedures could be made.

42 CFR 82.18 - How will NIOSH calculate internal dose to the primary cancer site(s)?

Code of Federal Regulations, 2010 CFR

2010-10-01

... primary cancer site(s)? 82.18 Section 82.18 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND... Dose Reconstruction Process § 82.18 How will NIOSH calculate internal dose to the primary cancer site(s... cancer covered by a claim is in a tissue not covered by existing ICRP models, NIOSH will use the ICRP...

42 CFR 82.18 - How will NIOSH calculate internal dose to the primary cancer site(s)?

Code of Federal Regulations, 2011 CFR

2011-10-01

... primary cancer site(s)? 82.18 Section 82.18 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND... Dose Reconstruction Process § 82.18 How will NIOSH calculate internal dose to the primary cancer site(s... cancer covered by a claim is in a tissue not covered by existing ICRP models, NIOSH will use the ICRP...

42 CFR 82.18 - How will NIOSH calculate internal dose to the primary cancer site(s)?

Code of Federal Regulations, 2013 CFR

2013-10-01

... primary cancer site(s)? 82.18 Section 82.18 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND... Dose Reconstruction Process § 82.18 How will NIOSH calculate internal dose to the primary cancer site(s... cancer covered by a claim is in a tissue not covered by existing ICRP models, NIOSH will use the ICRP...

42 CFR 82.18 - How will NIOSH calculate internal dose to the primary cancer site(s)?

Code of Federal Regulations, 2014 CFR

2014-10-01

... primary cancer site(s)? 82.18 Section 82.18 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND... Dose Reconstruction Process § 82.18 How will NIOSH calculate internal dose to the primary cancer site(s... cancer covered by a claim is in a tissue not covered by existing ICRP models, NIOSH will use the ICRP...

42 CFR 82.18 - How will NIOSH calculate internal dose to the primary cancer site(s)?

Code of Federal Regulations, 2012 CFR

2012-10-01

... primary cancer site(s)? 82.18 Section 82.18 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND... Dose Reconstruction Process § 82.18 How will NIOSH calculate internal dose to the primary cancer site(s... cancer covered by a claim is in a tissue not covered by existing ICRP models, NIOSH will use the ICRP...

[Interest and limits of inductively coupled plasma mass spectrometry (ICP-MS) for urinary diagnosis of radionuclide internal contamination].

PubMed

Lecompte, Yannick; Bohand, Sandra; Laroche, Pierre; Cazoulat, Alain

2013-01-01

After a review of radiometric reference methods used in radiotoxicology, analytical performance of inductively coupled plasma mass spectrometry (ICP-MS) for the workplace urinary diagnosis of internal contamination by radionuclides are evaluated. A literature review (covering the period from 2000 to 2012) is performed to identify the different applications of ICP-MS in radiotoxicology for urine analysis. The limits of detection are compared to the recommendations of the International commission on radiological protection (ICRP 78: "Individual monitoring for internal exposure of workers"). Except one publication describing the determination of strontium-90 (β emitter), all methods using ICP-MS reported in the literature concern actinides (α emitters). For radionuclides with a radioactive period higher than 10(4) years, limits of detection are most often in compliance with ICRP publication 78 and frequently lower than radiometric methods. ICP-MS allows the specific determination of plutonium-239 + 240 isotopes which cannot be discriminated by α spectrometry. High resolution ICP-MS can also measure uranium isotopic ratios in urine for total uranium concentrations lower than 20 ng/L. The interest of ICP-MS in radiotoxicology concerns essentially the urinary measurement of long radioactive period actinides, particularly for uranium isotope ratio determination and 239 and 240 plutonium isotopes discrimination. Radiometric methods remain the most efficient for the majority of other radionuclides.

Assessment of physician and patient (child and adult) equivalent doses during renal angiography by Monte Carlo method.

PubMed

Karimian, A; Nikparvar, B; Jabbari, I

2014-11-01

Renal angiography is one of the medical imaging methods in which patient and physician receive high equivalent doses due to long duration of fluoroscopy. In this research, equivalent doses of some radiosensitive tissues of patient (adult and child) and physician during renal angiography have been calculated by using adult and child Oak Ridge National Laboratory phantoms and Monte Carlo method (MCNPX). The results showed, in angiography of right kidney in a child and adult patient, that gall bladder with the amounts of 2.32 and 0.35 mSv, respectively, has received the most equivalent dose. About the physician, left hand, left eye and thymus absorbed the most amounts of doses, means 0.020 mSv. In addition, equivalent doses of the physician's lens eye, thyroid and knees were 0.023, 0.007 and 7.9E-4 mSv, respectively. Although these values are less than the reported thresholds by ICRP 103, it should be noted that these amounts are related to one examination. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Current risk estimates based on the A-bomb survivors data - a discussion in terms of the ICRP recommendations on the neutron weighting factor.

PubMed

Rühm, W; Walsh, L

2007-01-01

Currently, most analyses of the A-bomb survivors' solid tumour and leukaemia data are based on a constant neutron relative biological effectiveness (RBE) value of 10 that is applied to all survivors, independent of their distance to the hypocentre at the time of bombing. The results of these analyses are then used as a major basis for current risk estimates suggested by the International Commission on Radiological Protection (ICRP) for use in international safety guidelines. It is shown here that (i) a constant value of 10 is not consistent with weighting factors recommended by the ICRP for neutrons and (ii) it does not account for the hardening of the neutron spectra in Hiroshima and Nagasaki, which takes place with increasing distance from the hypocentres. The purpose of this paper is to present new RBE values for the neutrons, calculated as a function of distance from the hypocentres for both cities that are consistent with the ICRP60 neutron weighting factor. If based on neutron spectra from the DS86 dosimetry system, these calculations suggest values of about 31 at 1000 m and 23 at 2000 m ground range in Hiroshima, while the corresponding values for Nagasaki are 24 and 22. If the neutron weighting factor that is consistent with ICRP92 is used, the corresponding values are about 23 and 21 for Hiroshima and 21 and 20 for Nagasaki, respectively. It is concluded that the current risk estimates will be subject to some changes in view of the changed RBE values. This conclusion does not change significantly if the new doses from the Dosimetry System DS02 are used.

Utilization of MAX and FAX human phantoms for space radiation exposure calculations using HZETRN

NASA Astrophysics Data System (ADS)

Qualls, Garry; Slaba, Tony; Clowdsley, Martha; Blattnig, Steve; Walker, Steven; Simonsen, Lisa

To estimate astronaut health risk due to space radiation, one must have the ability to calculate, for known radiation environments external to the body, particle spectra, LET spectra, dose, dose equivalent, or gray equivalent that are averaged over specific organs or tissue types. This may be accomplished using radiation transport software and computational human body tissue models. Historically, NASA scientists have used the HZETRN software to calculate radiation transport through both vehicle shielding materials and body tissue. The Computerized Anatomical Man (CAM) and the Computerized Anatomical Female (CAF) body models, combined with the CAMERA software, have been used for body tissue self-shielding calculations. The CAM and CAF, which were developed in 1973 and 1992, respectively, model the 50th percentile U.S. Air Force male and female and are constructed using individual quadric surfaces that combine to form thousands of solid regions that represent specific tissues and structures within the body. In order to transport an external radiation environment to a point within one of the body models using HZETRN, a directional distribution of the tissues surrounding that point is needed. The CAMERA software is used to "ray trace" the CAM and CAF models, providing the thickness of each tissue type traversed along each of a large number of rays originating at a dose point. More recently, R. Kramer of the Departmento de Energia Nuclear, Universidade Federal de Pernambuco in Brazil and his co-workers developed the Male Adult voXel (MAX) model and the Female Adult voXel (FAX). These voxel-based body models were developed using segmented Computed Tomography (CT) scans of adult cadavers, and the quantities and distributions of various body tissues have been adjusted to match those specified in the International Commission on Radiological Protection (ICRP) reference adult male and female. A new set of tools has been developed to facilitate space radiation exposure calculation using HZETRN and the MAX and FAX models. A new ray tracer was developed for these body models, as was a methodology for evaluating organ-averaged quantities. Both tools are described in this paper and utilized in sample calculations.

FASH and MASH: female and male adult human phantoms based on polygon mesh surfaces: II. Dosimetric calculations

NASA Astrophysics Data System (ADS)

Kramer, R.; Cassola, V. F.; Khoury, H. J.; Vieira, J. W.; de Melo Lima, V. J.; Robson Brown, K.

2010-01-01

Female and male adult human phantoms, called FASH (Female Adult meSH) and MASH (Male Adult meSH), have been developed in the first part of this study using 3D animation software and anatomical atlases to replace the image-based FAX06 and the MAX06 voxel phantoms. 3D modelling methods allow for phantom development independent from medical images of patients, volunteers or cadavers. The second part of this study investigates the dosimetric implications for organ and tissue equivalent doses due to the anatomical differences between the new and the old phantoms. These differences are mainly caused by the supine position of human bodies during scanning in order to acquire digital images for voxel phantom development. Compared to an upright standing person, in image-based voxel phantoms organs are often coronally shifted towards the head and sometimes the sagittal diameter of the trunk is reduced by a gravitational change of the fat distribution. In addition, volumes of adipose and muscle tissue shielding internal organs are sometimes too small, because adaptation of organ volumes to ICRP-based organ masses often occurs at the expense of general soft tissues, such as adipose, muscle or unspecified soft tissue. These effects have dosimetric consequences, especially for partial body exposure, such as in x-ray diagnosis, but also for whole body external exposure and for internal exposure. Using the EGSnrc Monte Carlo code, internal and external exposure to photons and electrons has been simulated with both pairs of phantoms. The results show differences between organ and tissue equivalent doses for the upright standing FASH/MASH and the image-based supine FAX06/MAX06 phantoms of up to 80% for external exposure and up to 100% for internal exposure. Similar differences were found for external exposure between FASH/MASH and REGINA/REX, the reference voxel phantoms of the International Commission on Radiological Protection. Comparison of effective doses for external photon exposure showed good agreement between FASH/MASH and REGINA/REX, but large differences between FASH/MASH and the mesh-based RPI_AM and the RPI_AF phantoms, developed at the Rensselaer Polytechnic Institute (RPI).

ICRP Publication 132: Radiological Protection from Cosmic Radiation in Aviation.

PubMed

Lochard, J; Bartlett, D T; Rühm, W; Yasuda, H; Bottollier-Depois, J-F

2016-06-01

In this publication, the International Commission on Radiological Protection (ICRP) provides updated guidance on radiological protection from cosmic radiation in aviation, taking into account the current ICRP system of radiological protection, the latest available data on exposures in aviation, and experience gained worldwide in the management of exposures in aviation. The publication describes the origins of cosmic radiation, how it exposes passengers and aircraft crew, the basic radiological protection principles that apply to this existing exposure situation, and the available protective actions. For implementation of the optimisation principle, the Commission recommends a graded approach proportionate to the level of exposure that may be received by individuals. The objective is to keep the exposure of the most exposed individuals to a reasonable level. The Commission also recommends that information be disseminated to raise awareness about cosmic radiation, and to support informed decisions among concerned stakeholders.

ICRP draft publication on 'radiological protection against radon exposure'.

PubMed

Lecomte, J-F

2014-07-01

To control the main part of radon exposure, the Main Commission of the International Commission on Radiological Protection (ICRP) recommends an integrated approach focused as far as possible on the management of the building or location in which radon exposure occurs whatever the purpose of the building and the types of its occupants. This approach is based on the optimisation principle and a graded approach according to the degree of responsibilities at stake, notably in workplace, as well as the level of ambition of the national authorities. The report which is being developed by the Committee 4 is considering the recently consolidated ICRP general recommendations, the new scientific knowledge about the radon risk and the experience gained by many organisations and countries in the control of radon exposure. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

[Application of ICP-mS in the health risk assessment of heavy metals for drinking water sources in reservoirs].

PubMed

Gao, Bo; Li, Qiang; Zhou, Huai-Dong; Gao, Ji-Jun; Zou, Xiao-Wen; Yong, Huang

2014-05-01

The six heavy metal concentrations (Cr, Cr, As, Cd, Cu, Zn and Pb) in water samples collected from five reservoirs of Liao River Basin were studied. The health risk assessment for heavy metals pollution in reservoirs was conducted based on the environmental health risk assessment model recommended by U. S. Environmental Protection Agency. The results showed that the average concentrations of Cr, Cu, Zn, As, Cd and Pb in five reservoirs of Liao River Basin were 3.36, 1.03, 2. 70, 1.23, 0. 02 and 0. 03 microg L-1, respectively. In fact, these heavy metals concentrations were obviously lower than the Standard of National Drinking Water in China (GB 5749-2006). The results also showed that the metal carcinogenic risk was relatively high in this region. The order of the risk level of carcinogenic metals was Cr>As>Cd. The highest carcinogenic risk was from Cr, with the risk for adults ranging from 4. 50 X 10(-5) approximately 7. 53 X 10(-5) a-1' and the risk for children ranging from 6. 29 X 10(-5) to 1. 05 X 10(-4) a-1. The health risk levels caused by non-carcinogenic metals ranging from 10-13 to 10(-10) a-1 were lower than the acceptable range suggested by International Commission on Radiological Protection (ICRP) and the order of the risk level of non-carcinogenic metals was Cu>Zn>Pb. The total health risk of heavy metals for adults ranging from 1. 07X 10(-4) to 1. 72X 10(-4) a-1 and for children ranging from 1. 49 X 10(-4) to 2. 40 X 10(-4) a-1 exceeded the accepted level of 5 X 10(-5) a-1 as suggested by ICRP. The health risk levels of carcinogenic metals were significantly higher than those of non-carcinogenic metals in the reservoirs for Liao River Basin.

Pragmatic ethical basis for radiation protection in diagnostic radiology.

PubMed

Malone, Jim; Zölzer, Friedo

2016-01-01

Medical ethics has a tried and tested literature and a global active research community. Even among health professionals, literate and fluent in medical ethics, there is low recognition of radiation protection principles such as justification and optimization. On the other hand, many in healthcare environments misunderstand dose limitation obligations and incorrectly believe patients are protected by norms including a dose limit. Implementation problems for radiation protection in medicine possibly flow from apparent inadequacies of the International Commission on Radiological Protection (ICRP) principles taken on their own, coupled with their failure to transfer successfully to the medical world. Medical ethics, on the other hand, is essentially global, is acceptable in most cultures, is intuitively understood in hospitals, and its expectations are monitored, even by managements. This article presents an approach to ethics in diagnostic imaging rooted in the medical tradition, and alert to contemporary social expectations. ICRP and the International Radiation Protection Association (IRPA), both alert to growing ethical concerns, organized a series of consultations on ethics for general radiation protection in the last few years. The literature on medical ethics and implicit ICRP ethical values were reviewed qualitatively, with a view to identifying a system that will help guide contemporary behaviour in radiation protection of patients. Application of the system is illustrated in six clinical scenarios. The proposed system is designed, as far as is possible, so as not to be in conflict with the conclusions emerging from the ICRP/IRPA consultations. A widely recognized and well-respected system of medical ethics was identified that has global reach and claims acceptance in all cultures. Three values based on this system are grouped with two additional values to provide an ethical framework for application in diagnostic imaging. This system has the potential to be robust and to reach conclusions that are in accord with contemporary medical, social and ethical thinking. The system is not intended to replace the ICRP principles. Rather, it is intended as a well-informed interim approach that will help judge and analyse situations that arouse ethical concerns in radiology. Six scenarios illustrate the practicality of the value system in alerting one to possible deficits in practice. Five widely recognized values and the basis for them are identified to support the contemporary practice of diagnostic radiology. These are essential to complement the widely used ICRP principles pending further development in the area.

Development of computational pregnant female and fetus models and assessment of radiation dose from positron-emitting tracers.

PubMed

Xie, Tianwu; Zaidi, Habib

2016-12-01

Molecular imaging using PET and hybrid (PET/CT and PET/MR) modalities nowadays plays a pivotal role in the clinical setting for diagnosis and staging, treatment response monitoring, and radiation therapy treatment planning of a wide range of oncologic malignancies. The developing embryo/fetus presents a high sensitivity to ionizing radiation. Therefore, estimation of the radiation dose delivered to the embryo/fetus and pregnant patients from PET examinations to assess potential radiation risks is highly praised. We constructed eight embryo/fetus models at various gestation periods with 25 identified tissues according to reference data recommended by the ICRP publication 89 representing the anatomy of the developing embryo/fetus. The developed embryo/fetus models were integrated into realistic anthropomorphic computational phantoms of the pregnant female and used for estimating, using Monte Carlo calculations, S-values of common positron-emitting radionuclides, organ absorbed dose, and effective dose of a number of positron-emitting labeled radiotracers. The absorbed dose is nonuniformly distributed in the fetus. The absorbed dose of the kidney and liver of the 8-week-old fetus are about 47.45 % and 44.76 % higher than the average absorbed dose of the fetal total body for all investigated radiotracers. For 18 F-FDG, the fetal effective doses are 2.90E-02, 3.09E-02, 1.79E-02, 1.59E-02, 1.47E-02, 1.40E-02, 1.37E-02, and 1.27E-02 mSv/MBq at the 8th, 10th, 15th, 20th, 25th, 30th, 35th, and 38th weeks of gestation, respectively. The developed pregnant female/fetus models matching the ICRP reference data can be exploited by dedicated software packages for internal and external dose calculations. The generated S-values will be useful to produce new standardized dose estimates to pregnant patients and embryo/fetus from a variety of positron-emitting labeled radiotracers.

Assessment of impact of urbanisation on background radiation exposure and human health risk estimation in Kuala Lumpur, Malaysia.

PubMed

Sanusi, M S M; Ramli, A T; Hassan, W M S W; Lee, M H; Izham, A; Said, M N; Wagiran, H; Heryanshah, A

2017-07-01

Kuala Lumpur has been undergoing rapid urbanisation process, mainly in infrastructure development. The opening of new township and residential in former tin mining areas, particularly in the heavy mineral- or tin-bearing alluvial soil in Kuala Lumpur, is a contentious subject in land-use regulation. Construction practices, i.e. reclamation and dredging in these areas are potential to enhance the radioactivity levels of soil and subsequently, increase the existing background gamma radiation levels. This situation is worsened with the utilisation of tin tailings as construction materials apart from unavoidable soil pollutions due to naturally occurring radioactive materials in construction materials, e.g. granitic aggregate, cement and red clay brick. This study was conducted to assess the urbanisation impacts on background gamma radiation in Kuala Lumpur. The study found that the mean value of measured dose rate was 251±6nGyh -1 (156-392nGyh -1 ) and 4 times higher than the world average value. High radioactivity levels of 238 U (95±12Bqkg -1 ), 232 Th (191±23Bqkg -1 ,) and 40 K (727±130Bqkg -1 ) in soil were identified as the major source of high radiation exposure. Based on statistical ANOVA, t-test, and analyses of cumulative probability distribution, this study has statistically verified the dose enhancements in the background radiation. The effective dose was estimated to be 0.31±0.01mSvy -1 per man. The recommended ICRP reference level (1-20mSvy -1 ) is applicable to the involved existing exposure situation in this study. The estimated effective dose in this study is lower than the ICRP reference level and too low to cause deterministic radiation effects. Nevertheless based on estimations of lifetime radiation exposure risks, this study found that there was small probability for individual in Kuala Lumpur being diagnosed with cancer and dying of cancer. Copyright © 2017 Elsevier Ltd. All rights reserved.

Radiological protection in computed tomography and cone beam computed tomography.

PubMed

Rehani, M M

2015-06-01

The International Commission on Radiological Protection (ICRP) has sustained interest in radiological protection in computed tomography (CT), and ICRP Publications 87 and 102 focused on the management of patient doses in CT and multi-detector CT (MDCT) respectively. ICRP forecasted and 'sounded the alarm' on increasing patient doses in CT, and recommended actions for manufacturers and users. One of the approaches was that safety is best achieved when it is built into the machine, rather than left as a matter of choice for users. In view of upcoming challenges posed by newer systems that use cone beam geometry for CT (CBCT), and their widened usage, often by untrained users, a new ICRP task group has been working on radiological protection issues in CBCT. Some of the issues identified by the task group are: lack of standardisation of dosimetry in CBCT; the false belief within the medical and dental community that CBCT is a 'light', low-dose CT whereas mobile CBCT units and newer applications, particularly C-arm CT in interventional procedures, involve higher doses; lack of training in radiological protection among clinical users; and lack of dose information and tracking in many applications. This paper provides a summary of approaches used in CT and MDCT, and preliminary information regarding work just published for radiological protection in CBCT. © The International Society for Prosthetics and Orthotics Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Core ethical values of radiological protection applied to Fukushima case: reflecting common morality and cultural diversities.

PubMed

Kurihara, Chieko; Cho, Kunwoo; Toohey, Richard E

2016-12-01

The International Commission on Radiological Protection (ICRP) has established Task Group 94 (TG94) to develop a publication to clarify the ethical foundations of the radiological protection system it recommends. This TG identified four core ethical values which structure the system: beneficence and non-maleficence, prudence, justice, and dignity. Since the ICRP is an international organization, its recommendations and guidance should be globally applicable and acceptable. Therefore, first this paper presents the basic principles of the ICRP radiological protection system and its core ethical values, along with a reflection on the variation of these values in Western and Eastern cultural traditions. Secondly, this paper reflects upon how these values can be applied in difficult ethical dilemmas as in the case of the emergency and post-accident phases of a nuclear power plant accident, using the Fukushima case to illustrate the challenges at stake. We found that the core ethical values underlying the ICRP system of radiological protection seem to be quite common throughout the world, although there are some variations among various cultural contexts. Especially we found that 'prudence' would call for somewhat different implementation in each cultural context, balancing and integrating sometime conflicting values, but always with objectives to achieve the well-being of people, which is itself the ultimate aim of the radiological protection system.

Assessment of uncertainties in the lung activity measurement of low-energy photon emitters using Monte Carlo simulation of ICRP male thorax voxel phantom.

PubMed

Nadar, M Y; Akar, D K; Rao, D D; Kulkarni, M S; Pradeepkumar, K S

2015-12-01

Assessment of intake due to long-lived actinides by inhalation pathway is carried out by lung monitoring of the radiation workers inside totally shielded steel room using sensitive detection systems such as Phoswich and an array of HPGe detectors. In this paper, uncertainties in the lung activity estimation due to positional errors, chest wall thickness (CWT) and detector background variation are evaluated. First, calibration factors (CFs) of Phoswich and an array of three HPGe detectors are estimated by incorporating ICRP male thorax voxel phantom and detectors in Monte Carlo code 'FLUKA'. CFs are estimated for the uniform source distribution in lungs of the phantom for various photon energies. The variation in the CFs for positional errors of ±0.5, 1 and 1.5 cm in horizontal and vertical direction along the chest are studied. The positional errors are also evaluated by resizing the voxel phantom. Combined uncertainties are estimated at different energies using the uncertainties due to CWT, detector positioning, detector background variation of an uncontaminated adult person and counting statistics in the form of scattering factors (SFs). SFs are found to decrease with increase in energy. With HPGe array, highest SF of 1.84 is found at 18 keV. It reduces to 1.36 at 238 keV. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Development of a web-based CT dose calculator: WAZA-ARI.

PubMed

Ban, N; Takahashi, F; Sato, K; Endo, A; Ono, K; Hasegawa, T; Yoshitake, T; Katsunuma, Y; Kai, M

2011-09-01

A web-based computed tomography (CT) dose calculation system (WAZA-ARI) is being developed based on the modern techniques for the radiation transport simulation and for software implementation. Dose coefficients were calculated in a voxel-type Japanese adult male phantom (JM phantom), using the Particle and Heavy Ion Transport code System. In the Monte Carlo simulation, the phantom was irradiated with a 5-mm-thick, fan-shaped photon beam rotating in a plane normal to the body axis. The dose coefficients were integrated into the system, which runs as Java servlets within Apache Tomcat. Output of WAZA-ARI for GE LightSpeed 16 was compared with the dose values calculated similarly using MIRD and ICRP Adult Male phantoms. There are some differences due to the phantom configuration, demonstrating the significance of the dose calculation with appropriate phantoms. While the dose coefficients are currently available only for limited CT scanner models and scanning options, WAZA-ARI will be a useful tool in clinical practice when development is finalised.

Radiation assessment to paediatric with F-18-FDG undergo whole-body PET/CT examination

NASA Astrophysics Data System (ADS)

Dhalisa, H.; Mohamad, A. S.; Rafidah, Z.

2016-01-01

This study was carried out on wholebody radiation dose assessment to paediatrics patient who undergo PET/CT scanner at Institut Kanser Negara. Consist of 68 patients with varies of malignancies and epilepsy disease case covering age between 2 years to 12 years old. This is a retrospective study from 2010-2014. The use of PET/CT scanner as an advanced tool has been proven to give an extra radiation dose to the patient. It is because of the radiation exposure from the combination of both CT and PET scans rather than a single CT or PET scan. Furthermore, a study on radiation dose to paediatric patient undergoing PET/CT is rare in Malaysia. So, the aim of this study is to estimate the wholebody effective dose to paediatric patient in Malaysia. Effective dose from PET scan was calculated based on the activity of F18 FDG and dose coefficient reported in International Commission on Radiological Protection (ICRP) Publication 106. Effective dose from CT was determined using k coefficient as reported in ICRP publication 102 and Dose Length Product (DLP) value. The average effective dose from PET and CT were found to be 7.05mSv and 5.77mSv respectively. The mean wholebody effective dose received by a patient with combined PETCT examination was 12.78mSv. These results could be used as reference for dosimetry of a patient undergoing PETCT examination in Malaysia.

Radiation assessment to paediatric with F-18-FDG undergo whole-body PET/CT examination

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dhalisa, H., E-mail: dhalisa82@gmail.com; Rafidah, Z.; Mohamad, A. S.

2016-01-22

This study was carried out on wholebody radiation dose assessment to paediatrics patient who undergo PET/CT scanner at Institut Kanser Negara. Consist of 68 patients with varies of malignancies and epilepsy disease case covering age between 2 years to 12 years old. This is a retrospective study from 2010-2014. The use of PET/CT scanner as an advanced tool has been proven to give an extra radiation dose to the patient. It is because of the radiation exposure from the combination of both CT and PET scans rather than a single CT or PET scan. Furthermore, a study on radiation dosemore » to paediatric patient undergoing PET/CT is rare in Malaysia. So, the aim of this study is to estimate the wholebody effective dose to paediatric patient in Malaysia. Effective dose from PET scan was calculated based on the activity of F18 FDG and dose coefficient reported in International Commission on Radiological Protection (ICRP) Publication 106. Effective dose from CT was determined using k coefficient as reported in ICRP publication 102 and Dose Length Product (DLP) value. The average effective dose from PET and CT were found to be 7.05mSv and 5.77mSv respectively. The mean wholebody effective dose received by a patient with combined PETCT examination was 12.78mSv. These results could be used as reference for dosimetry of a patient undergoing PETCT examination in Malaysia.« less

Response Funtions for Computing Absorbed Dose to Skeletal Tissues from Photon Irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eckerman, Keith F; Bolch, W E; Zankl, M

2007-01-01

The calculation of absorbed dose in skeletal tissues at radiogenic risk has been a difficult problem because the relevant structures cannot be represented in conventional geometric terms nor can they be visualised in the tomographic image data used to define the computational models of the human body. The active marrow, the tissue of concern in leukaemia induction, is present within the spongiosa regions of trabecular bone, whereas the osteoprogenitor cells at risk for bone cancer induction are considered to be within the soft tissues adjacent to the mineral surfaces. The International Commission on Radiological Protection (ICRP) recommends averaging the absorbedmore » energy over the active marrow within the spongiosa and over the soft tissues within 10 mm of the mineral surface for leukaemia and bone cancer induction, respectively. In its forthcoming recommendation, it is expected that the latter guidance will be changed to include soft tissues within 50 mm of the mineral surfaces. To address the computational problems, the skeleton of the proposed ICRP reference computational phantom has been subdivided to identify those voxels associated with cortical shell, spongiosa and the medullary cavity of the long bones. It is further proposed that the Monte Carlo calculations with these phantoms compute the energy deposition in the skeletal target tissues as the product of the particle fluence in the skeletal subdivisions and applicable fluence-to-dose response functions. This paper outlines the development of such response functions for photons.« less

Estimating Effective Dose of Radiation From Pediatric Cardiac CT Angiography Using a 64-MDCT Scanner: New Conversion Factors Relating Dose-Length Product to Effective Dose.

PubMed

Trattner, Sigal; Chelliah, Anjali; Prinsen, Peter; Ruzal-Shapiro, Carrie B; Xu, Yanping; Jambawalikar, Sachin; Amurao, Maxwell; Einstein, Andrew J

2017-03-01

The purpose of this study is to determine the conversion factors that enable accurate estimation of the effective dose (ED) used for cardiac 64-MDCT angiography performed for children. Anthropomorphic phantoms representative of 1- and 10-year-old children, with 50 metal oxide semiconductor field-effect transistor dosimeters placed in organs, underwent scanning performed using a 64-MDCT scanner with different routine clinical cardiac scan modes and x-ray tube potentials. Organ doses were used to calculate the ED on the basis of weighting factors published in 1991 in International Commission on Radiological Protection (ICRP) publication 60 and in 2007 in ICRP publication 103. The EDs and the scanner-reported dose-length products were used to determine conversion factors for each scan mode. The effect of infant heart rate on the ED and the conversion factors was also assessed. The mean conversion factors calculated using the current definition of ED that appeared in ICRP publication 103 were as follows: 0.099 mSv · mGy -1 · cm -1 , for the 1-year-old phantom, and 0.049 mSv · mGy -1 · cm -1 , for the 10-year-old phantom. These conversion factors were a mean of 37% higher than the corresponding conversion factors calculated using the older definition of ED that appeared in ICRP publication 60. Varying the heart rate did not influence the ED or the conversion factors. Conversion factors determined using the definition of ED in ICRP publication 103 and cardiac, rather than chest, scan coverage suggest that the radiation doses that children receive from cardiac CT performed using a contemporary 64-MDCT scanner are higher than the radiation doses previously reported when older chest conversion factors were used. Additional up-to-date pediatric cardiac CT conversion factors are required for use with other contemporary CT scanners and patients of different age ranges.

Report of Task Group on the implications of the implementation of the ICRP recommendations for a revised dose limit to the lens of the eye.

PubMed

Broughton, J; Cantone, M C; Ginjaume, M; Shah, B

2013-12-01

This report was commissioned by the IRPA President to provide an assessment of the impact on members of IRPA Associate Societies of the introduction of ICRP recommendations for a reduced dose limit for the lens of the eye. The report summarises current practice and considers possible changes that may be required. Recommendations for further collaboration, clarification and changes to working practices are suggested.

Doses and risks from the ingestion of Dounreay fuel fragments.

PubMed

Darley, P J; Charles, M W; Fell, T P; Harrison, J D

2003-01-01

The radiological implications of ingestion of nuclear fuel fragments present in the marine environment around Dounreay have been reassessed by using the Monte Carlo code MCNP to obtain improved estimates of the doses to target cells in the walls of the lower large intestine resulting from the passage of a fragment. The approach takes account of the reduction in dose due to attenuation within the intestinal wall and self-absorption of radiation in the fuel fragment itself. In addition, dose is calculated on the basis of a realistic estimate of the anatomical volume of the lumen, rather than being based on the average mass of the contents, as in the current ICRP model. Our best estimates of doses from the ingestion of the largest Dounreay particles are at least a factor of 30 lower than those predicted using the current ICRP model. The new ICRP model will address the issues raised here and provide improved estimates of dose.

Construction of boundary-surface-based Chinese female astronaut computational phantom and proton dose estimation

PubMed Central

Sun, Wenjuan; JIA, Xianghong; XIE, Tianwu; XU, Feng; LIU, Qian

2013-01-01

With the rapid development of China's space industry, the importance of radiation protection is increasingly prominent. To provide relevant dose data, we first developed the Visible Chinese Human adult Female (VCH-F) phantom, and performed further modifications to generate the VCH-F Astronaut (VCH-FA) phantom, incorporating statistical body characteristics data from the first batch of Chinese female astronauts as well as reference organ mass data from the International Commission on Radiological Protection (ICRP; both within 1% relative error). Based on cryosection images, the original phantom was constructed via Non-Uniform Rational B-Spline (NURBS) boundary surfaces to strengthen the deformability for fitting the body parameters of Chinese female astronauts. The VCH-FA phantom was voxelized at a resolution of 2 × 2 × 4 mm3for radioactive particle transport simulations from isotropic protons with energies of 5000–10 000 MeV in Monte Carlo N-Particle eXtended (MCNPX) code. To investigate discrepancies caused by anatomical variations and other factors, the obtained doses were compared with corresponding values from other phantoms and sex-averaged doses. Dose differences were observed among phantom calculation results, especially for effective dose with low-energy protons. Local skin thickness shifts the breast dose curve toward high energy, but has little impact on inner organs. Under a shielding layer, organ dose reduction is greater for skin than for other organs. The calculated skin dose per day closely approximates measurement data obtained in low-Earth orbit (LEO). PMID:23135158

A feasibility study on the use of phantoms with statistical lung masses for determining the uncertainty in the dose absorbed by the lung from broad beams of incident photons and neutrons

PubMed Central

Khankook, Atiyeh Ebrahimi; Hakimabad, Hashem Miri

2017-01-01

Abstract Computational models of the human body have gradually become crucial in the evaluation of doses absorbed by organs. However, individuals may differ considerably in terms of organ size and shape. In this study, the authors sought to determine the energy-dependent standard deviations due to lung size of the dose absorbed by the lung during external photon and neutron beam exposures. One hundred lungs with different masses were prepared and located in an adult male International Commission on Radiological Protection (ICRP) reference phantom. Calculations were performed using the Monte Carlo N-particle code version 5 (MCNP5). Variation in the lung mass caused great uncertainty: ~90% for low-energy broad parallel photon beams. However, for high-energy photons, the lung-absorbed dose dependency on the anatomical variation was reduced to <1%. In addition, the results obtained indicated that the discrepancy in the lung-absorbed dose varied from 0.6% to 8% for neutron beam exposure. Consequently, the relationship between absorbed dose and organ volume was found to be significant for low-energy photon sources, whereas for higher energy photon sources the organ-absorbed dose was independent of the organ volume. In the case of neutron beam exposure, the maximum discrepancy (of 8%) occurred in the energy range between 0.1 and 5 MeV. PMID:28077627

The development of a population of 4D pediatric XCAT phantoms for imaging research and optimization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Segars, W. P., E-mail: paul.segars@duke.edu; Norris, Hannah; Sturgeon, Gregory M.

Purpose: We previously developed a set of highly detailed 4D reference pediatric extended cardiac-torso (XCAT) phantoms at ages of newborn, 1, 5, 10, and 15 yr with organ and tissue masses matched to ICRP Publication 89 values. In this work, we extended this reference set to a series of 64 pediatric phantoms of varying age and height and body mass percentiles representative of the public at large. The models will provide a library of pediatric phantoms for optimizing pediatric imaging protocols. Methods: High resolution positron emission tomography-computed tomography data obtained from the Duke University database were reviewed by a practicingmore » experienced radiologist for anatomic regularity. The CT portion of the data was then segmented with manual and semiautomatic methods to form a target model defined using nonuniform rational B-spline surfaces. A multichannel large deformation diffeomorphic metric mapping algorithm was used to calculate the transform from the best age matching pediatric XCAT reference phantom to the patient target. The transform was used to complete the target, filling in the nonsegmented structures and defining models for the cardiac and respiratory motions. The complete phantoms, consisting of thousands of structures, were then manually inspected for anatomical accuracy. The mass for each major tissue was calculated and compared to linearly interpolated ICRP values for different ages. Results: Sixty four new pediatric phantoms were created in this manner. Each model contains the same level of detail as the original XCAT reference phantoms and also includes parameterized models for the cardiac and respiratory motions. For the phantoms that were 10 yr old and younger, we included both sets of reproductive organs. This gave them the capability to simulate both male and female anatomy. With this, the population can be expanded to 92. Wide anatomical variation was clearly seen amongst the phantom models, both in organ shape and size, even for models of the same age and sex. The phantoms can be combined with existing simulation packages to generate realistic pediatric imaging data from different modalities. Conclusions: This work provides a large cohort of highly detailed pediatric phantoms with 4D capabilities of varying age, height, and body mass. The population of phantoms will provide a vital tool with which to optimize 3D and 4D pediatric imaging devices and techniques in terms of image quality and radiation-absorbed dose.« less

Pragmatic ethical basis for radiation protection in diagnostic radiology

PubMed Central

Zölzer, Friedo

2016-01-01

Objective: Medical ethics has a tried and tested literature and a global active research community. Even among health professionals, literate and fluent in medical ethics, there is low recognition of radiation protection principles such as justification and optimization. On the other hand, many in healthcare environments misunderstand dose limitation obligations and incorrectly believe patients are protected by norms including a dose limit. Implementation problems for radiation protection in medicine possibly flow from apparent inadequacies of the International Commission on Radiological Protection (ICRP) principles taken on their own, coupled with their failure to transfer successfully to the medical world. Medical ethics, on the other hand, is essentially global, is acceptable in most cultures, is intuitively understood in hospitals, and its expectations are monitored, even by managements. This article presents an approach to ethics in diagnostic imaging rooted in the medical tradition, and alert to contemporary social expectations. ICRP and the International Radiation Protection Association (IRPA), both alert to growing ethical concerns, organized a series of consultations on ethics for general radiation protection in the last few years. Methods: The literature on medical ethics and implicit ICRP ethical values were reviewed qualitatively, with a view to identifying a system that will help guide contemporary behaviour in radiation protection of patients. Application of the system is illustrated in six clinical scenarios. The proposed system is designed, as far as is possible, so as not to be in conflict with the conclusions emerging from the ICRP/IRPA consultations. Results and conclusion: A widely recognized and well-respected system of medical ethics was identified that has global reach and claims acceptance in all cultures. Three values based on this system are grouped with two additional values to provide an ethical framework for application in diagnostic imaging. This system has the potential to be robust and to reach conclusions that are in accord with contemporary medical, social and ethical thinking. The system is not intended to replace the ICRP principles. Rather, it is intended as a well-informed interim approach that will help judge and analyse situations that arouse ethical concerns in radiology. Six scenarios illustrate the practicality of the value system in alerting one to possible deficits in practice. Advances in knowledge: Five widely recognized values and the basis for them are identified to support the contemporary practice of diagnostic radiology. These are essential to complement the widely used ICRP principles pending further development in the area. PMID:26796852

The internal dosimetry code PLEIADES.

PubMed

Fell, T P; Phipps, A W; Smith, T J

2007-01-01

The International Commission on Radiological Protection (ICRP) has published dose coefficients for the ingestion or inhalation of radionuclides in a series of reports covering intakes by workers and members of the public, including children and pregnant or lactating women. The calculation of these coefficients divides naturally into two distinct parts-the biokinetic and dosimetric. This paper describes in detail the methods used to solve the biokinetic problem in the generation of dose coefficients on behalf of the ICRP, as implemented in the Health Protection Agency's internal dosimetry code PLEIADES. A summary of the dosimetric treatment is included.

Human biokinetics of strontium. Part I: intestinal absorption rate and its impact on the dose coefficient of 90Sr after ingestion.

PubMed

Li, Wei Bo; Höllriegl, Vera; Roth, Paul; Oeh, Uwe

2006-07-01

Intestinal absorption of strontium (Sr) in thirteen healthy adult German volunteers has been investigated by simultaneous oral and intravenous administration of two stable tracer isotopes, i.e. (84)Sr and (86)Sr. The measured Sr tracer concentration in plasma was analyzed using the convolution integral technique to obtain the intestinal absorption rate. The results showed that the Sr labeled in different foodstuffs was absorbed into the body fluids in a large range of difference. The maximum Sr absorption rates were observed within 60-120 min after administration. The rate of absorption is used to evaluate the intestinal absorption fraction, i.e. the f (1) value for various foodstuffs. The equivalent and effective dose coefficients for ingestion of (90)Sr were calculated using these f (1) values, and they were compared with those recommended by the International Commission on Radiological Protection (ICRP). The geometric and arithmetic means of the f (1) values are 0.38 and 0.45 associated with a geometric standard deviation and a standard deviation of 1.88 and 0.22, respectively. The 90% confidence interval of the f (1) values obtained in the present study ranges from 0.13 to 0.98. Expressed as the ratio of the 95 and 50% percentiles of the estimated probability, the uncertainty for the f (1) value corresponds to a factor of 2.58. The effective dose coefficients of (90)Sr after ingestion are 6.1 x 10(-9) Sv Bq(-1) for an f(1) value of 0.05, 1.0 x 10(-8) Sv Bq(-1) for 0.1, 1.9 x 10(-8) Sv Bq(-1) for 0.2, 2.8 x 10(-8) Sv Bq(-1) for 0.3, 3.6 x 10(-8) Sv Bq(-1) for 0.4, 5.3 x 10(-8) Sv Bq(-1) for 0.6, 7.1 x 10(-8) Sv Bq(-1) for 0.8, and 7.9 x 10(-8) Sv Bq(-1) for 0.9, respectively. Taking the effective dose coefficient of 2.8 x 10(-8) Sv Bq(-1) for an f (1) value of 0.3, which is recommended by the ICRP, as a reference, the effective dose coefficient of (90)Sr after ingestion varies by a factor of 2.8 when the f (1) value changes by a factor of 3, i.e. it decreases from 0.3 to 0.1 or increases from 0.3 to 0.9, respectively.

The conversion of exposures due to radon into the effective dose: the epidemiological approach.

PubMed

Beck, T R

2017-11-01

The risks and dose conversion coefficients for residential and occupational exposures due to radon were determined with applying the epidemiological risk models to ICRP representative populations. The dose conversion coefficient for residential radon was estimated with a value of 1.6 mSv year -1 per 100 Bq m -3 (3.6 mSv per WLM), which is significantly lower than the corresponding value derived from the biokinetic and dosimetric models. The dose conversion coefficient for occupational exposures with applying the risk models for miners was estimated with a value of 14 mSv per WLM, which is in good accordance with the results of the dosimetric models. To resolve the discrepancy regarding residential radon, the ICRP approaches for the determination of risks and doses were reviewed. It could be shown that ICRP overestimates the risk for lung cancer caused by residential radon. This can be attributed to a wrong population weighting of the radon-induced risks in its epidemiological approach. With the approach in this work, the average risks for lung cancer were determined, taking into account the age-specific risk contributions of all individuals in the population. As a result, a lower risk coefficient for residential radon was obtained. The results from the ICRP biokinetic and dosimetric models for both, the occupationally exposed working age population and the whole population exposed to residential radon, can be brought in better accordance with the corresponding results of the epidemiological approach, if the respective relative radiation detriments and a radiation-weighting factor for alpha particles of about ten are used.

Studies on radon/thoron and their decay products in granite quarries around Bangalore city, India

NASA Astrophysics Data System (ADS)

Ningappa, C.; Sannappa, J.; Chandrashekara, M. S.; Paramesh, L.

2009-08-01

The radon survey was performed in granite quarries around Bangalore rural district and Bangalore city as part of a lung cancer epidemiological study. Long duration measurements of indoor and outdoor radon, thoron and their progenies concentrations were made around granite quarries of Bangalore rural district by using Solid State Nuclear Track Detector (SSNTD, LR-115, Type-II Plastic track detector) during summer and winter period (2006-07). The increase of radioactivity in granite quarries and inhalation dose to workers and populations near the quarries have been summarized. The higher concentrations of radon and thoron in granite quarries suggest radiation health effects on workers and public around the quarries is higher than permissible levels. The results are presented and analyzed with reference to ICRP limits.

Whole-body voxel phantoms of paediatric patients—UF Series B

NASA Astrophysics Data System (ADS)

Lee, Choonik; Lee, Choonsik; Williams, Jonathan L.; Bolch, Wesley E.

2006-09-01

Following the previous development of the head and torso voxel phantoms of paediatric patients for use in medical radiation protection (UF Series A), a set of whole-body voxel phantoms of paediatric patients (9-month male, 4-year female, 8-year female, 11-year male and 14-year male) has been developed through the attachment of arms and legs from segmented CT images of a healthy Korean adult (UF Series B). Even though partial-body phantoms (head-torso) may be used in a variety of medical dose reconstruction studies where the extremities are out-of-field or receive only very low levels of scatter radiation, whole-body phantoms play important roles in general radiation protection and in nuclear medicine dosimetry. Inclusion of the arms and legs is critical for dosimetry studies of paediatric patients due to the presence of active bone marrow within the extremities of children. While the UF Series A phantoms preserved the body dimensions and organ masses as seen in the original patients who were scanned, comprehensive adjustments were made for the Series B phantoms to better match International Commission on Radiological Protection (ICRP) age-interpolated reference body masses, body heights, sitting heights and internal organ masses. The CT images of arms and legs of a Korean adult were digitally rescaled and attached to each phantom of the UF series. After completion, the resolutions of the phantoms for the 9-month, 4-year, 8-year, 11-year and 14-year were set at 0.86 mm × 0.86 mm × 3.0 mm, 0.90 mm × 0.90 mm × 5.0 mm, 1.16 mm × 1.16 mm × 6.0 mm, 0.94 mm × 0.94 mm × 6.00 mm and 1.18 mm × 1.18 mm × 6.72 mm, respectively.

Basis for the ICRP’s updated biokinetic model for carbon inhaled as CO 2

DOE PAGES

Leggett, Richard W.

2017-03-02

Here, the International Commission on Radiological Protection (ICRP) is updating its biokinetic and dosimetric models for occupational intake of radionuclides (OIR) in a series of reports called the OIR series. This paper describes the basis for the ICRP's updated biokinetic model for inhalation of radiocarbon as carbon dioxide (CO 2) gas. The updated model is based on biokinetic data for carbon isotopes inhaled as carbon dioxide or injected or ingested as bicarbonatemore » $$({{{\\rm{HCO}}}_{3}}^{-}).$$ The data from these studies are expected to apply equally to internally deposited (or internally produced) carbon dioxide and bicarbonate based on comparison of excretion rates for the two administered forms and the fact that carbon dioxide and bicarbonate are largely carried in a common form (CO 2–H$${{{\\rm{CO}}}_{3}}^{-})$$ in blood. Compared with dose estimates based on current ICRP biokinetic models for inhaled carbon dioxide or ingested carbon, the updated model will result in a somewhat higher dose estimate for 14C inhaled as CO 2 and a much lower dose estimate for 14C ingested as bicarbonate.« less

An improved MCNP version of the NORMAN voxel phantom for dosimetry studies.

PubMed

Ferrari, P; Gualdrini, G

2005-09-21

In recent years voxel phantoms have been developed on the basis of tomographic data of real individuals allowing new sets of conversion coefficients to be calculated for effective dose. Progress in radiation studies brought ICRP to revise its recommendations and a new report, already circulated in draft form, is expected to change the actual effective dose evaluation method. In the present paper the voxel phantom NORMAN developed at HPA, formerly NRPB, was employed with MCNP Monte Carlo code. A modified version of the phantom, NORMAN-05, was developed to take into account the new set of tissues and weighting factors proposed in the cited ICRP draft. Air kerma to organ equivalent dose and effective dose conversion coefficients for antero-posterior and postero-anterior parallel photon beam irradiations, from 20 keV to 10 MeV, have been calculated and compared with data obtained in other laboratories using different numerical phantoms. Obtained results are in good agreement with published data with some differences for the effective dose calculated employing the proposed new tissue weighting factors set in comparison with previous evaluations based on the ICRP 60 report.

ICRP Publication 107. Nuclear decay data for dosimetric calculations.

PubMed

Eckerman, K; Endo, A

2008-01-01

In this report, the Commission provides an electronic database of the physical data needed in calculations of radionuclide-specific protection and operational quantities. This database supersedes the data of Publication 38 (ICRP, 1983), and will be used in future ICRP publications of dose coefficients for the intake of or exposure to radionuclides in the workplace and the environment.The database contains information on the half-lives, decay chains, and yields and energies of radiations emitted in nuclear transformations of 1252 radionuclides of 97 elements. The CD accompanying the publication provides electronic access to complete tables of the emitted radiations, as well as the beta and neutron spectra. The database has been constructed such that user-developed software can extract the data needed for further calculations of a radionuclide of interest. A Windows-based application is provided to display summary information on a user-specified radionuclide, as well as the general characterisation of the nuclides contained in the database. In addition, the application provides a means by which the user can export the emissions of a specified radionuclide for use in subsequent calculations.

Medical and occupational dose reduction in pediatric barium meal procedures

NASA Astrophysics Data System (ADS)

Filipov, D.; Schelin, H. R.; Denyak, V.; Paschuk, S. A.; Ledesma, J. A.; Legnani, A.; Bunick, A. P.; Sauzen, J.; Yagui, A.; Vosiak, P.

2017-11-01

Doses received in pediatric Barium Meal procedure can be rather high. It is possible to reduce dose values following the recommendations of the European Communities (EC) and the International Commission on Radiological Protection (ICRP). In the present work, the modifications of radiographic techniques made in a Brazilian hospital according to the EC and the ICRP recommendations and their influence on medical and occupational exposure are reported. The procedures of 49 patients before and 44 after the optimization were studied and air kerma-area product (PK,A) values and the effective doses were evaluated. The occupational equivalent doses were measured next to the eyes, under the thyroid shield and on each hand of both professionals who remained inside the examination room. The implemented modifications reduced by 70% and 60% the PK,A and the patient effective dose, respectively. The obtained dose values are lower than approximately 75% of the results from similar studies. The occupational annual equivalent doses for all studied organs became lower than the limits set by the ICRP. The equivalent doses in one examination were on average below than 75% of similar studies.

Basis for the ICRP’s updated biokinetic model for carbon inhaled as CO 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leggett, Richard W.

Here, the International Commission on Radiological Protection (ICRP) is updating its biokinetic and dosimetric models for occupational intake of radionuclides (OIR) in a series of reports called the OIR series. This paper describes the basis for the ICRP's updated biokinetic model for inhalation of radiocarbon as carbon dioxide (CO 2) gas. The updated model is based on biokinetic data for carbon isotopes inhaled as carbon dioxide or injected or ingested as bicarbonatemore » $$({{{\\rm{HCO}}}_{3}}^{-}).$$ The data from these studies are expected to apply equally to internally deposited (or internally produced) carbon dioxide and bicarbonate based on comparison of excretion rates for the two administered forms and the fact that carbon dioxide and bicarbonate are largely carried in a common form (CO 2–H$${{{\\rm{CO}}}_{3}}^{-})$$ in blood. Compared with dose estimates based on current ICRP biokinetic models for inhaled carbon dioxide or ingested carbon, the updated model will result in a somewhat higher dose estimate for 14C inhaled as CO 2 and a much lower dose estimate for 14C ingested as bicarbonate.« less

KDEP: A resource for calculating particle deposition in the respiratory tract

DOE PAGES

Klumpp, John A.; Bertelli, Luiz

2017-08-01

This study presents KDEP, an open-source implementation of the ICRP lung deposition model developed by the authors. KDEP, which is freely available to the public, can be used to calculate lung deposition values under a variety of different conditions using the ICRP methodology. The paper describes how KDEP implements this model and discusses some key points of the implementation. The published lung deposition values for intakes by workers were reproduced, and new deposition values were calculated for intakes by members of the public. KDEP can be obtained for free at github.com or by emailing the authors directly.

Absorbed organ and effective doses from digital intra-oral and panoramic radiography applying the ICRP 103 recommendations for effective dose estimations

PubMed Central

Thilander-Klang, Anne; Ylhan, Betȕl; Lofthag-Hansen, Sara; Ekestubbe, Annika

2016-01-01

Objective: During dental radiography, the salivary and thyroid glands are at radiation risk. In 2007, the International Commission on Radiological Protection (ICRP) updated the methodology for determining the effective dose, and the salivary glands were assigned tissue-specific weighting factors for the first time. The aims of this study were to determine the absorbed dose to the organs and to calculate, applying the ICRP publication 103 tissue-weighting factors, the effective doses delivered during digital intraoral and panoramic radiography. Methods: Thermoluminescent dosemeter measurements were performed on an anthropomorphic head and neck phantom. The organ-absorbed doses were measured at 30 locations, representing different radiosensitive organs in the head and neck, and the effective dose was calculated according to the ICRP recommendations. Results: The salivary glands and the oral mucosa received the highest absorbed doses from both intraoral and panoramic radiography. The effective dose from a full-mouth intraoral examination was 15 μSv and for panoramic radiography, the effective dose was in the range of 19–75 μSv, depending on the panoramic equipment used. Conclusion: The effective dose from a full-mouth intraoral examination is lower and that from panoramic radiography is higher than previously reported. Clinicians should be aware of the higher effective dose delivered during panoramic radiography and the risk–benefit profile of this technique must be assessed for the individual patient. Advances in knowledge: The effective dose of radiation from panoramic radiography is higher than previously reported and there is large variability in the delivered radiation dosage among the different types of equipment used. PMID:27452261

Human respiratory tract model for radiological protection: a revision of the ICRP Dosimetric Model for the Respiratory System.

PubMed

Bair, W J

1989-01-01

In 1984, the International Commission on Radiological Protection (ICRP) appointed a task group of Committee 2 to review and revise, as necessary, the ICRP Dosimetric Model for the Respiratory System. The model was originally published in 1966, modified slightly in Publication No. 19, and again in Publication No. 30 (in 1979). The task group concluded that research during the past 20 y suggested certain deficiencies in the ICRP Dosimetric Model for the Respiratory System. Research has also provided sufficient information for a revision of the model. The task group's approach has been to review, in depth, morphology and physiology of the respiratory tract; deposition of inhaled particles in the respiratory tract; clearance of deposited materials; and the nature and specific sites of damage to the respiratory tract caused by inhaled radioactive substances. This review has led to a redefinition of the regions of the respiratory tract for dosimetric purposes. The redefinition has a morphologic and physiological basis and is consistent with observed deposition and clearance of particles and with resultant pathology. Regions, as revised, are the extrathoracic (E-T) region, comprising the nasal and oral regions, the pharynx, larynx, and upper part of the trachea; the fast-clearing thoracic region (T[f]), comprising the remainder of the trachea and bronchi; and the slow-clearing thoracic region (T[s]), comprising the bronchioles, alveoli, and thoracic lymph nodes. A task group report will include models for calculating radiation doses to these regions of the respiratory tract following inhalation of representative alpha-, beta-, and gamma-emitting particulate and gaseous radionuclides. The models may be implemented as a package of computer codes available to a wide range of users. This should facilitate application of the revised human respiratory tract model to worldwide radiation protection needs.

A feasibility study on the use of phantoms with statistical lung masses for determining the uncertainty in the dose absorbed by the lung from broad beams of incident photons and neutrons.

PubMed

Khankook, Atiyeh Ebrahimi; Hakimabad, Hashem Miri; Motavalli, Laleh Rafat

2017-05-01

Computational models of the human body have gradually become crucial in the evaluation of doses absorbed by organs. However, individuals may differ considerably in terms of organ size and shape. In this study, the authors sought to determine the energy-dependent standard deviations due to lung size of the dose absorbed by the lung during external photon and neutron beam exposures. One hundred lungs with different masses were prepared and located in an adult male International Commission on Radiological Protection (ICRP) reference phantom. Calculations were performed using the Monte Carlo N-particle code version 5 (MCNP5). Variation in the lung mass caused great uncertainty: ~90% for low-energy broad parallel photon beams. However, for high-energy photons, the lung-absorbed dose dependency on the anatomical variation was reduced to <1%. In addition, the results obtained indicated that the discrepancy in the lung-absorbed dose varied from 0.6% to 8% for neutron beam exposure. Consequently, the relationship between absorbed dose and organ volume was found to be significant for low-energy photon sources, whereas for higher energy photon sources the organ-absorbed dose was independent of the organ volume. In the case of neutron beam exposure, the maximum discrepancy (of 8%) occurred in the energy range between 0.1 and 5 MeV. © The Author 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Candela-Juan, Cristian; Perez-Calatayud, Jose; Ballester, Facundo

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 {sup 60}Co or {sup 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 frommore » an adult reference man defined in ICRP Publication 89. Point sources of {sup 60}Co or {sup 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 {sup 60}Co source were smaller (8%-19%) than from {sup 192}Ir. However, as the distance increases, the more penetrating gamma rays produced by {sup 60}Co deliver higher organ equivalent doses. The overall result is that effective dose per clinical absorbed dose from a {sup 60}Co source (11.1 mSv/Gy) is lower than from a {sup 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 variations between both phantoms which were at most 35% in the considered organ equivalent doses. Finally, effective doses per clinical absorbed dose from IMRT and proton therapy were comparable to those from both brachytherapy sources, with brachytherapy being advantageous over external beam radiation therapy for the furthest organs. Conclusions: A database of organ equivalent doses when applying HDR brachytherapy to the prostate with either {sup 60}Co or {sup 192}Ir is provided. According to physical considerations, {sup 192}Ir is dosimetrically advantageous over {sup 60}Co sources at large distances, but not in the closest organs. Damage to distant healthy organs per clinical absorbed dose is lower with brachytherapy than with IMRT or protons, although the overall effective dose per Gy given to the prostate seems very similar. Given that there are several possible fractionation schemes, which result in different total amounts of therapeutic absorbed dose, advantage of a radiation treatment (according to equivalent dose to healthy organs) is treatment and facility dependent.« less

History and Organizations for Radiological Protection.

PubMed

Kang, Keon Wook

2016-02-01

International Commission on Radiological Protection (ICRP), an independent international organization established in 1925, develops, maintains, and elaborates radiological protection standards, legislation, and guidelines. United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) provides scientific evidence. World Health Organization (WHO) and International Atomic Energy Agency (IAEA) utilise the ICRP recommendations to implement radiation protection in practice. Finally, radiation protection agencies in each country adopt the policies, and adapt them to each situation. In Korea, Nuclear Safety and Security Commission is the governmental body for nuclear safety regulation and Korea Institute of Nuclear Safety is a public organization for technical support and R&D in nuclear safety and radiation protection.

Dental radiographic guidelines: a review.

PubMed

Kim, Irene H; Mupparapu, Muralidhar

2009-05-01

The 2004 American Dental Association (ADA)/US Food and Drug Administration (FDA) radiographic selection criteria and guidelines were reviewed and compared with the prior radiographic selection criteria and guidelines. The authors reviewed the publications from the US FDA, US Department of Health and Human Services, and National Council on Radiation Protection and Measurements. The positions outlined by the Canadian Dental Association and the European Commission were also reviewed and compared to US guidelines. The FDA guidelines were first published in 1987, and several changes have been made to them over the years. Recent literature reveals that the general compliance of these guidelines is very low, especially within dental schools in the United States and Canada. Little is known about the compliance outside of the dental school environment; however, it is expected to be low for various reasons. In 2007, the International Commission on Radiological Protection (ICRP) revised its estimates of tissue radiosensitivity, which resulted in effective doses of dental radiographs 32% to 422% higher than the 1990 ICRP guidelines. Flow charts summarizing the latest guidelines were developed to facilitate general compliance among practitioners. Based on the literature reviewed and the recent ICRP findings, it would be prudent for dental health care professionals to follow dental radiographic guidelines.

Radiation-induced cataracts: the Health Protection Agency's response to the ICRP statement on tissue reactions and recommendation on the dose limit for the eye lens.

PubMed

Bouffler, Simon; Ainsbury, Elizabeth; Gilvin, Phil; Harrison, John

2012-12-01

This paper presents the response of the Health Protection Agency (HPA) to the 2011 statement from the International Commission on Radiological Protection (ICRP) on tissue reactions and recommendation of a reduced dose limit for the lens of the eye. The response takes the form of a brief review of the most recent epidemiological and mechanistic evidence. This is presented together with a discussion of dose limits in the context of the related risk and the current status of eye dosimetry, which is relevant for implementation of the limits. It is concluded that although further work is desirable to quantify better the risk at low doses and following protracted exposures, along with research into the mechanistic basis for radiation cataractogenesis to inform selection of risk projection models, the HPA endorses the conclusion reached by the ICRP in their 2011 statement that the equivalent dose limit for the lens of the eye should be reduced from 150 to 20 mSv per year, averaged over a five year period, with no year's dose exceeding 50 mSv.

Availability of nuclear decay data in electronic form, including beta spectra not previously published

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eckerman, K.F.; Westfall, R.J.; Ryman, J.C.

1994-10-01

The unabridged data used in preparing ICRP Publication 38 (1983) and a monograph of the Medical Internal Radiation Dose (MIRD) Committee are now available in electronic form. The {open_quotes}ICRP38 collection{close_quotes} contains data on the energies and intensities of radiations emitted by 825 radionuclides (those in ICRP Publication 38 plus 13 from the MIRD monograph), and the {open_quotes}MIRD collection{close_quotes} contains data on 242 radionuclides. Each collection consists of a radiations data file and a beta spectra data file. The radiations data file contains the complete listing of the emitted radiations, their types, mean or unique energies, and absolute intensities for eachmore » radionuclide, the probability that a beta particle will be emitted with kinetic energies defined by a standard energy grid. Although summary information from the radiation data files has been published, neither the unabridged data nor the beta spectra have been published. These data files and a data extraction utility, which runs on a personal computer, are available from the Radiation Shielding Information Center at Oak Ridge National Laboratory. 13 refs., 1 fig., 6 tabs.« less

Letter to the Editor: Appropriate selection of dose coefficients in radiological assessments: C-14 and Cl-36: response to the letter of G Smith and M Thorne (2015 J. Radiol. Prot. 35 737-40)

DOE PAGES

Harrison, John D.; Leggett, Richard Wayne

2016-01-01

This letter to the editor of Journal of Radiological Protection is in response to a letter to the editor from G. M. Smith and M. C. Thorne of Great Britain concerning the appropriate selection of dose coefficients for ingested carbon-14 and chlorine-36, two of the most important long-lived components of radioactive wastes. Smith and Thorne argue that current biokinetic models of the International Commission on Radiological Protection (ICRP) for carbon and chlorine are overly cautious models from the standpoint of radiation dose estimates for C-14 and Cl-36, and that more realistic models are needed for evaluation of the hazards ofmore » these radionuclides in nuclear wastes. We (Harrison and Leggett) point out that new biokinetic models for these and other elements (developed at ORNL) will soon appear in ICRP Publications. These new models generally are considerably more realistic than current ICRP models. Here, examples are given for C-14 inhaled as carbon dioxide or ingested in water as bicarbonate, carbonate, or carbon dioxide.« less

Assessing the reliability of dose coefficients for exposure to radioiodine by members of the public, accounting for dosimetric and risk model uncertainties.

PubMed

Puncher, M; Zhang, W; Harrison, J D; Wakeford, R

2017-06-26

Assessments of risk to a specific population group resulting from internal exposure to a particular radionuclide can be used to assess the reliability of the appropriate International Commission on Radiological Protection (ICRP) dose coefficients used as a radiation protection device for the specified exposure pathway. An estimate of the uncertainty on the associated risk is important for informing judgments on reliability; a derived uncertainty factor, UF, is an estimate of the 95% probable geometric difference between the best risk estimate and the nominal risk and is a useful tool for making this assessment. This paper describes the application of parameter uncertainty analysis to quantify uncertainties resulting from internal exposures to radioiodine by members of the public, specifically 1, 10 and 20-year old females from the population of England and Wales. Best estimates of thyroid cancer incidence risk (lifetime attributable risk) are calculated for ingestion or inhalation of 129 I and 131 I, accounting for uncertainties in biokinetic model and cancer risk model parameter values. These estimates are compared with the equivalent ICRP derived nominal age-, sex- and population-averaged estimates of excess thyroid cancer incidence to obtain UFs. Derived UF values for ingestion or inhalation of 131 I for 1 year, 10-year and 20-year olds are around 28, 12 and 6, respectively, when compared with ICRP Publication 103 nominal values, and 9, 7 and 14, respectively, when compared with ICRP Publication 60 values. Broadly similar results were obtained for 129 I. The uncertainties on risk estimates are largely determined by uncertainties on risk model parameters rather than uncertainties on biokinetic model parameters. An examination of the sensitivity of the results to the risk models and populations used in the calculations show variations in the central estimates of risk of a factor of around 2-3. It is assumed that the direct proportionality of excess thyroid cancer risk and dose observed at low to moderate acute doses and incorporated in the risk models also applies to very small doses received at very low dose rates; the uncertainty in this assumption is considerable, but largely unquantifiable. The UF values illustrate the need for an informed approach to the use of ICRP dose and risk coefficients.

On effective dose for radiotherapy based on doses to nontarget organs and tissues

DOE Office of Scientific and Technical Information (OSTI.GOV)

Uselmann, Adam J., E-mail: ajuselmann@wisc.edu; Thomadsen, Bruce R.

2015-02-15

Purpose: The National Council for Radiation Protection and Measurement (NCRP) published estimates for the collective population dose and the mean effective dose to the population of the United States from medical imaging procedures for 1980/1982 and for 2006. The earlier report ignored the effective dose from radiotherapy and the latter gave a cursory discussion of the topic but again did not include it in the population exposure for various reasons. This paper explains the methodology used to calculate the effective dose in due to radiotherapy procedures in the latter NCRP report and revises the values based on more detailed modeling.more » Methods: This study calculated the dose to nontarget organs from radiotherapy for reference populations using CT images and published peripheral dose data. Results: Using International Commission on Radiological Protection (ICRP) 60 weighting factors, the total effective dose to nontarget organs in radiotherapy patients is estimated as 298 ± 194 mSv per patient, while the U.S. population effective dose is 0.939 ± 0.610 mSv per person, with a collective dose of 283 000 ± 184 000 person Sv per year. Using ICRP 103 weighting factors, the effective dose is 281 ± 183 mSv per patient, 0.887 ± 0.577 mSv per person in the U.S., and 268 000 ± 174 000 person Sv per year. The uncertainty in the calculations is largely governed by variations in patient size, which was accounted for by considering a range of patient sizes and taking the average treatment site to nontarget organ distance. Conclusions: The methods used to estimate the effective doses from radiotherapy used in NCRP Report No. 160 have been explained and the values updated.« less

Overview of ICRP Committee 3: protection in medicine.

PubMed

Vañó, E; Miller, D L; Rehani, M M

2016-06-01

Committee 3 of the International Commission on Radiological Protection (ICRP) develops recommendations and guidance for protection of patients, staff, and the public against radiation exposure when ionising radiation is used for medical diagnosis, therapy, or biomedical research. This paper presents a summary of the work that Committee 3 has accomplished over the past few years, and also describes its current work. The most recent reports published by the Commission that relate to radiological protection in medicine are 'Radiological protection in cone beam computed tomography' (Publication 129), 'Radiation dose to patients from radiopharmaceuticals: a compendium of current information related to frequently used substances' (Publication 128, in cooperation with Committee 2), 'Radiological protection in ion beam radiotherapy' (Publication 127), 'Radiological protection in paediatric diagnostic and interventional radiology' (Publication 121), 'Radiological protection in cardiology' (Publication 120), and 'Radiological protection in fluoroscopically guided procedures outside the imaging department' (Publication 117). A new report on diagnostic reference levels in medical imaging will provide specific advice for interventional radiology, digital imaging, computed tomography, nuclear medicine, paediatrics, and hybrid (multi-modality) imaging procedures, and is expected to be published in 2016. Committee 3 is also working on guidance for occupational radiological protection in brachytherapy, and on guidance on occupational protection issues in interventional procedures, paying particular attention to the 2011 Commission's recommendations on the occupational dose limit for the lens of the eye (Publication 118). Other reports in preparation deal with justification, radiological protection in therapy with radiopharmaceuticals, radiological protection in medicine as related to individual radiosusceptibility, appropriate use of effective dose (in cooperation with other Committees), and guidance for healthcare practitioners on radiological and patient protection. Committee 3 has also suggested specific priorities for research on radiological protection in medicine to the Commission. © The International Society for Prosthetics and Orthotics.

Radiation Doses to Members of the U.S. Population from Ubiquitous Radionuclides in the Body: Part 3, Results, Variability, and Uncertainty

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watson, David J.; Strom, Daniel J.

This paper is part three of a three-part series investigating annual effective doses to residents of the United States from intakes of ubiquitous radionuclides, including radionuclides occurring naturally, radionuclides whose concentrations are technologically enhanced, and anthropogenic radionuclides. The radionuclides of interest are the 238U series (14 nuclides), the actinium series (headed by 235U; 11 nuclides), and the 232Th series (11 nuclides); primordial radionuclides 87Rb and 40K; cosmogenic and fallout radionuclides 14C and 3H; and purely anthropogenic radionuclides 137Cs-137mBa, 129I and 90Sr-90Y. This series of papers explicitly excludes intakes from inhaling 222Rn, 220Rn, and their short-lived decay products; it also excludesmore » intakes of radionuclides in occupational and medical settings. Part one reviewed, summarized, characterized, and grouped all published and some unpublished data for U.S. residents on ubiquitous radionuclide concentrations in tissues and organs. Part two described the methods used to organize the data collected in part one and segregate it into the ages and genders defined by the study, imputed missing values from the existing data, apportioned activity in bone, and imputed activity in hollow organ contents and the remainder of the body. This paper estimates equivalent doses to target tissues from source regions and maps target tissues to lists of tissues with International Commission on Radiation Protection (ICRP) tissue-weighting factors or to surrogate tissue regions when there is no direct match. Effective doses, using ICRP tissue-weighting factors recommended in 1977, 1990, and 2007, are then calculated, and an upper bound of variability of the effective dose is estimated by calculating the average coefficients of variation (CV), assuming all variance is due to variability. Most of the data were for adult males, whose average annual effective dose is estimated to be 337 μSv (CV = 0.65, geometric mean = 283 μSv, geometric standard deviation sG = 1.81) using 2007 ICRP tissue-weighting factors. This result is between the National Council on Radiation Protection & Measurements’ 1987 estimate of 390 μSv (using 1977 wTs) and its 2009 estimate of 285 μSv (using 2007 wTs) and is higher than the United Nations Scientific Committee on the Effects of Atomic Radiation’s 2000 estimate of 310 μSv (using 1990 wTs). The methods and software developed for this project are sufficiently detailed and sufficiently general to be usable with autopsy data from any or all countries.« less

Dosimetric assessment from 212Pb inhalation at a thorium purification plant.

PubMed

Campos, M P; Pecequilo, B R S

2004-01-01

At the Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, Brazil, there is a facility (thorium purification plant) where materials with high thorium concentrations are manipulated. In order to estimate afterwards the lung cancer risk for the workers, the thoron daughter (212Pb) levels were assessed and the committed effective and lung committed equivalent doses for workers in place. A total of 28 air filter samples were measured by total alpha counting through the modified Kusnetz method, to determine the 212Pb concentraion. The committed effective dose and lung committed equivalent dose due to 212Pb inhalation were derived from compartmental analysis following the ICRP 66 lung compartmental model, and ICRP 67 lead metabolic model.

Dosimetry of {sup 210}Po in humans, caribou, and wolves in northern Canada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomas, P.A.

1994-06-01

Effective doses from {sup 210}Po intake with caribou meat were determined for human residents in Baker Lake and Snowdrift in the Northwest Territories of Canada and compared to doses calculated from reported {sup 210}Po tissue activities in Alaskan and British residents. Effective doses were calculated to separate body tissues, using ICRP 60 human weighting factors and the ICRP 30 metabolic model for {sup 210}Po. Baker Lake and Alaskan effective doses were similar at 0.4 mSv y{sup {minus}1} and slightly higher than Snowdrift doses (0.3 mSv y{sup {minus}1}). Alaskan tissue activities indicated higher effective doses to liver, bone surfaces and redmore » marrow and lower doses to spleen than the {sup 210}Po metabolic model (ICRP 1979a) predicts. Effective doses to Baker Lake and Snowdrift caribou and wolves, calculated from tissue activities, ranged from 7-20 mSv y{sup {minus}1} using human weighting factors for comparison to human doses only. Effective doses to northern Canadians and wildlife were, respectively, 7-11% and 1.8-5 times an estimated human background of 4 mSv y{sup {minus}} from all sources. 51 refs., 2 figs., 9 tabs.« less

Self-reference enhances relational memory in young and older adults.

PubMed

Hou, Mingzhu; Grilli, Matthew D; Glisky, Elizabeth L

2017-11-27

The present study investigated the influence of self-reference on two kinds of relational memory, internal source memory and associative memory, in young and older adults. Participants encoded object-location word pairs using the strategies of imagination and sentence generation, either with reference to themselves or to a famous other (i.e., George Clooney or Oprah Winfrey). Both young and older adults showed memory benefits in the self-reference conditions compared to other-reference conditions on both tests, and the self-referential effects in older adults were not limited by low memory or executive functioning. These results suggest that self-reference can benefit relational memory in older adults relatively independently of basic memory and executive functions.

Testing Moderating Detection Systems with {sup 252}Cf-Based Reference Neutron Fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hertel, Nolan E.; Sweezy, Jeremy; Sauber, Jeremiah S.

Calibration measurements were carried out on a probe designed to measure ambient dose equivalent in accordance with ICRP Pub 60 recommendations. It consists of a cylindrical {sup 3}He proportional counter surrounded by a 25-cm-diameter spherical polyethylene moderator. Its neutron response is optimized for dose rate measurements of neutrons between thermal energies and 20 MeV. The instrument was used to measure the dose rate in four separate neutron fields: unmoderated {sup 252}Cf, D{sub 2}O-moderated {sup 252}Cf, polyethylene-moderated {sup 252}Cf, and WEP neutron howitzer with {sup 252}Cf at its center. Dose equivalent measurements were performed at source-detector centerline distances from 50 tomore » 200 cm. The ratio of air-scatter- and room-return-corrected ambient dose equivalent rates to ambient dose equivalent rates calculated with the code MCNP are tabulated.« less

SU-E-T-511: Inter-Rater Variability in Classification of Incidents in a New Incident Reporting System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pappas, D; Reis, S; Ali, A

Purpose To determine how consistent the results of different raters are when reviewing the same cases within the Radiation Oncology Incident Learning System (ROILS). Methods Three second-year medical physics graduate students filled out incident reports in spreadsheets set up to mimic ROILS. All students studied the same 33 cases and independently entered their assessments, for a total of 99 reviewed cases. The narratives for these cases were obtained from a published International Commission on Radiological Protection (ICRP) report which included shorter narratives selected from the Radiation Oncology Safety Information System (ROSIS) database. Each category of questions was reviewed to seemore » how consistent the results were by utilizing free-marginal multirater kappa analysis. The percentage of cases where all raters shared full agreement or full disagreement was recorded to show which questions were answered consistently by multiple raters for a given case. The consistency among the raters was analyzed between ICRP and ROSIS cases to see if either group led to more reliable results. Results The categories where all raters agreed 100 percent in their choices were the event type (93.94 percent of cases 0.946 kappa) and the likelihood of the event being harmful to the patient (42.42 percent of cases 0.409 kappa). The categories where all raters disagreed 100 percent in their choices were the dosimetric severity scale (39.39 percent of cases 0.139 kappa) and the potential future toxicity (48.48 percent of cases 0.205 kappa). ROSIS had more cases where all raters disagreed than ICRP (23.06 percent of cases compared to 15.58 percent, respectively). Conclusion Despite reviewing the same cases, the results among the three raters was widespread. ROSIS narratives were shorter than ICRP, which suggests that longer narratives lead to more consistent results. This study shows that the incident reporting system can be optimized to yield more consistent results.« less

US Transuranium and Uranium Registries case study on accidental exposure to uranium hexafluoride.

PubMed

Avtandilashvili, Maia; Puncher, Matthew; McComish, Stacey L; Tolmachev, Sergei Y

2015-03-01

The United States Transuranium and Uranium Registries' (USTUR) whole-body donor (Case 1031) was exposed to an acute inhalation of uranium hexafluoride (UF6) produced from an explosion at a uranium processing plant 65 years prior to his death. The USTUR measurements of tissue samples collected at the autopsy indicated long-term retention of inhaled slightly enriched uranium material (0.85% (235)U) in the deep lungs and thoracic lymph nodes. In the present study, the authors combined the tissue measurement results with historical bioassay data, and analysed them with International Commission on Radiological Protection (ICRP) respiratory tract models and the ICRP Publication 69 systemic model for uranium using maximum likelihood and Bayesian statistical methods. The purpose of the analysis was to estimate intakes and model parameter values that best describe the data, and evaluate their effect on dose assessment. The maximum likelihood analysis, which used the ICRP Publication 66 human respiratory tract model, resulted in a point estimate of 79 mg of uranium for the occupational intake composed of 86% soluble, type F material and 14% insoluble, type S material. For the Bayesian approach, the authors applied the Markov Chain Monte Carlo method, but this time used the revised human respiratory tract model, which is currently being used by ICRP to calculate new dose coefficients for workers. The Bayesian analysis estimated that the mean uranium intake was 160 mg, and calculated the case-specific lung dissolution parameters with their associated uncertainties. The parameters were consistent with the inhaled uranium material being predominantly soluble with a small but significant insoluble component. The 95% posterior range of the rapid dissolution fraction (the fraction of deposited material that is absorbed to blood rapidly) was 0.12 to 0.91 with a median of 0.37. The remaining fraction was absorbed slowly, with a 95% range of 0.000 22 d(-1) to 0.000 36 d(-1) and a median of 0.000 31 d(-1). The effective dose per unit intake calculated using the dissolution parameters derived from the maximum likelihood and the Bayesian analyses was higher than the current ICRP dose coefficient for type F uranium by a factor of 2 or 7, respectively; the higher value of the latter was due to use of the revised respiratory tract model. The dissolution parameter values obtained here may be more appropriate to use for radiation protection purposes when individuals are exposed to a UF6 mixture that contains an insoluble uranium component.

A kinematic model to estimate the effective dose of radioactive isotopes in the human body for radiological protection

NASA Astrophysics Data System (ADS)

Sasaki, S.; Yamada, T.

2013-12-01

The great earthquake attacked the north-east area in Japan in March 11, 2011. The system of electrical facilities to control Fukushima Daiichi nuclear power station was completely destroyed by the following tsunamis. From the damaged reactor containment vessels, an amount of radioactive substances had leaked and been diffused in the vicinity of this station. Radiological internal exposure becomes a serious social issue both in Japan and all over the world. The present study provides an easily understandable, kinematic-based model to estimate the effective dose of radioactive substances in a human body by simplified the complicated mechanism of metabolism. International Commission on Radiological Protection (ICRP) has developed an exact model, which is well-known as a standard method to calculate the effective dose for radiological protection. However, owing to that the above method accord too much with the actual mechanism of metabolism in human bodies, it becomes rather difficult for non-professional people of radiology to gasp the whole images of the movement and the influences of radioactive substances in a human body. Therefore, in the present paper we propose a newly-derived and easily-understandable model to estimate the effective dose. The present method is very similar with the traditional and conventional hydrological tank model. Ingestion flux of radioactive substances corresponds to rain intensity and the storage of radioactive substances to the water storage in a basin in runoff analysis. The key of this method is to estimate the energy radiated from the radioactive nuclear disintegration of an atom by using classical theory of E. Fermi of beta decay and special relativity for various kinds of radioactive atoms. The parameters used in this study are only physical half-time and biological half-time, and there are no intentional and operational parameters of coefficients to adjust our theoretical runoff to observation of ICRP. Figure.1 compares time series of effective cesium-137 dose according to age calculated by ICRP software with calculated by the present method. Plots are calculated values by ICRP, the solid line is analytic solution given from the present method. It should be noted that the present study does not consider complicated mechanism, but it could give equally accurate results comparing to existing research. Time series of effective Cs-137 dose according to age when food contains 1 Bq/year is ingested for 1 year. (Plots are calculated values by ICRP. The solid line is analytic solution given from the present method)

Psychiatric Comorbidity and Functioning in a Clinically Referred Population of Adults with Autism Spectrum Disorders: A Comparative Study

ERIC Educational Resources Information Center

Joshi, Gagan; Wozniak, Janet; Petty, Carter; Martelon, Mary Kate; Fried, Ronna; Bolfek, Anela; Kotte, Amelia; Stevens, Jonathan; Furtak, Stephannie L.; Bourgeois, Michelle; Caruso, Janet; Caron, Ashley; Biederman, Joseph

2013-01-01

To systematically examine the patterns of psychiatric comorbidity and functioning in clinically referred adults with autism spectrum disorders (ASD). Psychiatrically referred adults with and without ASD were compared on measures assessing for psychiatric comorbidity and psychosocial functioning. Sixty-three adults with ASD participated in the…

Appropriate Use of Effective Dose in Radiation Protection and Risk Assessment.

PubMed

Fisher, Darrell R; Fahey, Frederic H

2017-08-01

Effective dose was introduced by the ICRP for the single, over-arching purpose of setting limits for radiation protection. Effective dose is a derived quantity or mathematical construct and not a physical, measurable quantity. The formula for calculating effective dose to a reference model incorporates terms to account for all radiation types, organ and tissue radiosensitivities, population groups, and multiple biological endpoints. The properties and appropriate applications of effective dose are not well understood by many within and outside the health physics profession; no other quantity in radiation protection has been more confusing or misunderstood. According to ICRP Publication 103, effective dose is to be used for "prospective dose assessment for planning and optimization in radiological protection, and retrospective demonstration of compliance for regulatory purposes." In practice, effective dose has been applied incorrectly to predict cancer risk among exposed persons. The concept of effective dose applies generally to reference models only and not to individual subjects. While conceived to represent a measure of cancer risk or heritable detrimental effects, effective dose is not predictive of future cancer risk. The formula for calculating effective dose incorporates committee-selected weighting factors for radiation quality and organ sensitivity; however, the organ weighting factors are averaged across all ages and both genders and thus do not apply to any specific individual or radiosensitive subpopulations such as children and young women. Further, it is not appropriate to apply effective dose to individual medical patients because patient-specific parameters may vary substantially from the assumptions used in generalized models. Also, effective dose is not applicable to therapeutic uses of radiation, as its mathematical underpinnings pertain only to observed late (stochastic) effects of radiation exposure and do not account for short-term adverse tissue reactions. The weighting factors incorporate substantial uncertainties, and linearity of the dose-response function at low dose is uncertain and highly disputed. Since effective dose is not predictive of future cancer incidence, it follows that effective dose should never be used to estimate future cancer risk from specific sources of radiation exposure. Instead, individual assessments of potential detriment should only be based on organ or tissue radiation absorbed dose, together with best scientific understanding of the corresponding dose-response relationships.

Development of a computer code to calculate the distribution of radionuclides within the human body by the biokinetic models of the ICRP.

PubMed

Matsumoto, Masaki; Yamanaka, Tsuneyasu; Hayakawa, Nobuhiro; Iwai, Satoshi; Sugiura, Nobuyuki

2015-03-01

This paper describes the Basic Radionuclide vAlue for Internal Dosimetry (BRAID) code, which was developed to calculate the time-dependent activity distribution in each organ and tissue characterised by the biokinetic compartmental models provided by the International Commission on Radiological Protection (ICRP). Translocation from one compartment to the next is taken to be governed by first-order kinetics, which is formulated by the first-order differential equations. In the source program of this code, the conservation equations are solved for the mass balance that describes the transfer of a radionuclide between compartments. This code is applicable to the evaluation of the radioactivity of nuclides in an organ or tissue without modification of the source program. It is also possible to handle easily the cases of the revision of the biokinetic model or the application of a uniquely defined model by a user, because this code is designed so that all information on the biokinetic model structure is imported from an input file. The sample calculations are performed with the ICRP model, and the results are compared with the analytic solutions using simple models. It is suggested that this code provides sufficient result for the dose estimation and interpretation of monitoring data. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A case study of the long-term retention of 137Cs after inhalation of high temperature reactor fuel element ash.

PubMed

Froning, M; Kozielewski, T; Schläger, M; Hill, P

2004-01-01

In 1987, a worker was internally contaminated with 137Cs as a result of an accident during the handling of high temperature reactor fuel element ash. In the long-term follow-up monitoring an unusual retention behaviour was found. The observed time dependence of caesium retention does not agree with the standard models of ICRP Publication 30. The present case can be better explained by assuming an intake of a mixture of type F and type S compounds. However, experimental data can be best described by a four-exponential retention function with two long-lived components, which was used as an ad hoc model for dose calculation. The resulting dose is compared with doses calculated on the basis of ICRP Publication 66.

Effect of Dietary Intake of Stable Iodine on Dose-per-unit-intake Factors for 99Tc

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strom, Daniel J.

It is well-known that the human thyroid concentrates iodine more than 100 times the concentration in plasma. Also well-known is the fact that large amounts of stable iodine in the diet can limit thyroid uptake of total iodine; this is the basis for administering potassium iodide following a release of radioiodine from a nuclear reactor accident or nuclear weapon detonation. Many researchers have shown enhanced concentrations of both organic and inorganic iodine in saliva and breast milk. Technetium-99 is a long-lived (231,000 year half-life) radionuclide of concern in the management of high-level radioactive waste. There is no doubt that 99Tc,more » if it is in groundwater, will be found in the chemical form of pertechnetate, 99TcO4?. Pertechnetate is a large anion, almost identical in size to iodide, I?. The nuclear medicine literature shows that pertechnetate concentrates in the thyroid, salivary glands, and lactating breast in addition to the stomach, liver, and alimentary tract as currently recognized by the International Commission on Radiological Protection (ICRP). The fact that large intakes of stable iodine (127I) in the diet limit uptake of iodine by the thyroid leads one to generalize that stable iodine in the diet may also limit thyroid uptake of pertechnetate. While there is at least one report that iodine in the diet blocks uptake of 99mTcO4? by the thyroid and salivary glands (which have the same Na/I symporter, the biochemical concentration mechanism), the level of protective effect seen for blocking radioactive iodine is not expected for 99TcO4? because pertechnetate does not become organically bound in the thyroid and thus is not retained for months the way iodide is. While it does account for Tc concentration in the thyroid, the existing ICRP biokinetic model for technetium does not take enhanced concentrations in salivary gland and breast tissue into account. From the survey of the nuclear medicine literature, it is not possible to compute the effect of stable iodine in the diet on the dose per unit intake factors for 99Tc without developing an improved biokinetic model for technetium. Specific experiments should be designed to quantitatively evaluate 99TcO4? metabolism, excretion, and secretion, as well as to evaluate its chemical toxicity It is recommended that the ICRP reexamine its biokinetics models for Tc based on nuclear medicine data that have accumulated over the years. In particular, the ICRP ignores the lactation pathway, the enhanced concentration of Tc in breast and breast milk, and enhanced concentration of Tc (and I) in the salivary glands as well as in the thyroid. The ICRP should also explicitly incorporate the effect of stable iodine in the diet into both its models for iodine and technetium. The effect of concentration of Tc in breast milk needs further study for dosimetric implications to nursing infants whose mothers may ingest 99TcO4? from groundwater sources. The ICRP should also investigate the possibility of enhanced concentration of both I and Tc in the non-lactating female breast. To do these re-evaluations of biokinetic models, new experiments designed specifically to evaluate these questions concerning the biokinetics of Tc and I are needed.« less

Measuring the differences in work ratios between pediatric and adult ophthalmologic examinations.

PubMed

Hyun, Joo; Chang, Jee Ho; Kim, Seung Hoon; Park, Song Hee; Kim, Sunghoon

2017-06-01

To assess the differences in work needed for pediatric and adult ophthalmologic examinations. Seven ophthalmology residents conducted slit-lamp and refraction examinations on children 3-7 years of age and adults 20-69 years of age. The examiners reported the magnitude estimate (ME) of their work in relation to two references (cross-reference ME): average adult examination and average pediatric examination. The examination time was also measured. For the slit-lamp examination, 50 children and 58 adults were recruited. The ME was 1.45 (95% CI, 1.30-1.62) times higher for the pediatric examinations than for the adult examinations when the reference was an average adult case. With respect to time, the pediatric examinations took 1.22 (95% CI, 1.06-1.41) times longer than the adult examinations. For the refraction examinations, 58 children and 96 adults were recruited. The ME was 1.35 (95% CI, 1.21-1.52) times higher for the pediatric examinations. The pediatric examination took 1.32 (95% CI, 1.16-1.50) times longer than the adult examination. The cross-reference ME ratios measuring the pediatric over adult examinations against both the pediatric and adult reference cases were equivalent in both the slit-lamp and the refraction examinations; however, the ME and time ratios of the pediatric over the adult examinations were not equivalent for the slit-lamp or for the refraction examinations. The cross-reference ME showed that pediatric ophthalmologic examinations require more work than the adult examination with validity and reliability. The time estimate was insufficient as a single indicator for work estimation. Copyright © 2017 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

Public member dose assessment of Bushehr Nuclear Power Plant under normal operation by modeling the fallout from stack using the HYSPLIT atmospheric dispersion model.

PubMed

Zali, A; Shamsaei Zafarghandi, M; Feghhi, S A; Taherian, A M

2017-05-01

In this work, public dose resulting from fission products released from Bushehr Nuclear Power Plant (BNPP) under normal operation is assessed. Due to the long range transport of radionuclides in this work (80 km) and considering terrain and meteorological data, HYbrid Single-Particle Lagrangian Integrated Trajectory (HYsplit) model, which uses three dimensional long-range numerical models, has been employed to calculate atmospheric dispersion. Annual effective dose calculation is carried out for inhalation, ingestion, and external exposure pathways in 16directions and within 80 km around the site for representative person. The results showed the maximum dose of inhalation and external exposure for adults is 3.8 × 10 -8 Sv/y in the SE direction and distance of 600 m from the BNPP site which is less than ICRP 103 recommended dose limit (1 mSv). Children and infants' doses are higher in comparison with adults, although they are less than 1 mSv. Ingestion dose percentage in the total dose is less than 0.1%. The results of this study underestimate the Final Safety Analysis Report ofBNPP-1 (FSAR)data. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparison of observed lung retention and urinary excretion of thorium workers and members of the public in India with the values predicted by the ICRP biokinetic model.

PubMed

Jaiswal, D D; Singh, I S; Nair, Suma; Dang, H S; Garg, S P; Pradhan, A S

2004-01-01

The daily intake of natural Th and its contents in lungs, skeleton and liver of an Indian adult population group were estimated using radiochemical neutron activation analysis (RNAA) technique. These data on daily intake (through inhalation and ingestion) were used to compute Th contents in lungs and other systemic organs such as skeleton and liver using the new human respiratory tract model (HRTM) and the new biokinetic model of Th. The theoretically computed Th contents in lungs, skeleton and liver of an average Indian adult are 2.56, 4.00 and 0.17 microg, respectively which are comparable with the corresponding experimentally measured values of 4.31, 3.45 and 0.14 microg in an urban population group living in Mumbai. The measured lung contents of Th in a group of five occupational workers were used to compute their total body Th contents and the corresponding daily urinary excretions. The computed total body contents and daily urinary excretions of Th in the five subjects compared favourably with their measured values. These studies, thus, validate the new biokinetic model of Th in natural as well as in occupational exposures in Indian conditions.

Ethics, genetics and dynamics: an emerging systematic approach to radiation protection of the environment.

PubMed

Pentreath, R J

2004-01-01

There is now a general consensus of opinion that an explicit approach is necessary to demonstrate radiation protection of the environment, and that this approach needs to be developed in a systematic way. The framework that is emerging links ethical and moral issues (anthropocentric, biocentric, and ecocentric) to broad-based principles and objectives of environmental protection (sustainable development, maintaining biological diversity, and habitat protection) and then links these, in turn, to the needs of current environmental management practices, such as environmental exploitation, pollution control, and nature conservation. The relevance of this to radiation is that its effects (such as causing early mortality, morbidity, reduced reproductive success, as well as resulting in observable (scorable) cytogenetic damage) are those that may have a bearing on these same environmental management practices. The devise that would appear to be most useful to bridge the gap between our disparate data on radiation effects and the needs of environmental management, is that of adding to the concept of Reference Man in the shape of a small set of Reference Animals and Plants. This approach has now been adopted by the ICRP, adding new dynamics-the motive forces, both moral and physical-to the subject. The way is now clear for rapid progress to be made on a number of fronts.

Evaluation of annual committed effective doses to members of the public in Morocco due to 238U and 232Th in various food materials.

PubMed

Misdaq, M A; Bourzik, W

2004-12-01

Uranium (238U) and thorium (232Th) concentrations were measured in different foods widely consumed in Morocco by using CR-39 and LR-115 type II solid state nuclear track detectors (SSNTDs). Annual committed effective doses due to 238U and 232Th intakes from the ingestion of the studied food materials were evaluated for different age groups of individuals, using the ICRP ingestion dose coefficients. The influence of the 238U and 232Th intakes and ages of individuals on the committed effective dose was investigated. Total annual intakes of 238U and 232Th for a typical food basket for adult members of the Moroccan population were estimated to be 451 +/- 27 Bq y(-1) and 359 +/- 20 Bq y(-1), corresponding to committed effective doses of (20 +/- 1) x 10(-6) Sv y(-1) and (83 +/- 5) x 10(-6) Sv y(-1), respectively.

Development and application of a complex numerical model and software for the computation of dose conversion factors for radon progenies.

PubMed

Farkas, Árpád; Balásházy, Imre

2015-04-01

A more exact determination of dose conversion factors associated with radon progeny inhalation was possible due to the advancements in epidemiological health risk estimates in the last years. The enhancement of computational power and the development of numerical techniques allow computing dose conversion factors with increasing reliability. The objective of this study was to develop an integrated model and software based on a self-developed airway deposition code, an own bronchial dosimetry model and the computational methods accepted by International Commission on Radiological Protection (ICRP) to calculate dose conversion coefficients for different exposure conditions. The model was tested by its application for exposure and breathing conditions characteristic of mines and homes. The dose conversion factors were 8 and 16 mSv WLM(-1) for homes and mines when applying a stochastic deposition model combined with the ICRP dosimetry model (named PM-A model), and 9 and 17 mSv WLM(-1) when applying the same deposition model combined with authors' bronchial dosimetry model and the ICRP bronchiolar and alveolar-interstitial dosimetry model (called PM-B model). User friendly software for the computation of dose conversion factors has also been developed. The software allows one to compute conversion factors for a large range of exposure and breathing parameters and to perform sensitivity analyses. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Dose conversion coefficients for electron exposure of the human eye lens: calculations including a whole body phantom.

PubMed

Behrens, R

2013-07-01

In this work, conversion coefficients from electron fluence to absorbed dose to the eye lens were calculated using Monte Carlo simulations based on a detailed stylised eye model and a very simple but whole body phantom. These data supersede and complement data published earlier based on the simulation of only a single stylised eye. The new data differ from the old ones by not more than 3, 4, 7 and 16 % for angles of radiation incidence of α=0°, 15°, 30° and 45°, respectively, due to the inclusion of the whole body phantom. The data presented in the present work also complement those of a recent report of the International Commission on Radiological Protection (ICRP) (ICRP Publication 116), where conversion coefficients from electron fluence to absorbed dose to the lens of the eye are shown for solely 0°, 180° and isotropic radiation incidence (but for a much broader range of energies). In this article, values are provided for angles of incidence of 0° up to 180° in steps of 15° and for rotational geometry; no systematic deviation was observed from the values given in ICRP Publication 116 for 0° (based on the application of a bare eye) and 180° (based on the application of a voxel whole body phantom). Data are given for monoenergetic electrons from 0.1 up to 10 MeV and for a broad parallel beam geometry in vacuum.

ICRP Publication 138: Ethical Foundations of the System of Radiological Protection.

PubMed

Cho, K-W; Cantone, M-C; Kurihara-Saio, C; Le Guen, B; Martinez, N; Oughton, D; Schneider, T; Toohey, R; ZöLzer, F

2018-02-01

Despite a longstanding recognition that radiological protection is not only a matter of science, but also ethics, ICRP publications have rarely addressed the ethical foundations of the system of radiological protection explicitly. The purpose of this publication is to describe how the Commission has relied on ethical values, either intentionally or indirectly, in developing the system of radiological protection with the objective of presenting a coherent view of how ethics is part of this system. In so doing, it helps to clarify the inherent value judgements made in achieving the aim of the radiological protection system as underlined by the Commission in Publication 103. Although primarily addressed to the radiological protection community, this publication is also intended to address authorities, operators, workers, medical professionals, patients, the public, and its representatives (e.g. NGOs) acting in the interest of the protection of people and the environment. This publication provides the key steps concerning the scientific, ethical, and practical evolutions of the system of radiological protection since the first ICRP publication in 1928. It then describes the four core ethical values underpinning the present system: beneficence/ non-maleficence, prudence, justice, and dignity. It also discusses how these core ethical values relate to the principles of radiological protection, namely justification, optimisation, and limitation. The publication finally addresses key procedural values that are required for the practical implementation of the system, focusing on accountability, transparency, and inclusiveness. The Commission sees this publication as a founding document to be elaborated further in different situations and circumstances.

Implementation of the integrated approach in different types of exposure scenarios.

PubMed

Copplestone, D; Hirth, G; Johansen, M; Lazo, E; Takala, J; Sakai, K; Yankovich, T

2018-01-01

The International Commission on Radiological Protection (ICRP) recognises three types of exposure situations: planned, existing, and emergency. In all three situations, the release of radionuclides into the natural environment leads to exposures of non-human biota, as well as the potential for exposures of the public. This paper describes how the key principles of the ICRP system of radiological protection apply to non-human biota and members of the public in each of these exposure situations. Current work in this area within ICRP Task Group 105 is highlighted. For example, how simplified numeric criteria may be used in planned exposure situations that are protective of both the public and non-human biota. In emergency exposure situations, the initial response will always be focused on human protection; however, understanding the potential impacts of radionuclide releases on non-human biota will likely become important in terms of communication as governments and the public seek to understand the exposures that are occurring. For existing exposure situations, there is a need to better understand the potential impacts of radionuclides on animals and plants, especially when deciding on protective actions. Understanding the comparative impacts from radiological, non-radiological, and physical aspects is often important in managing the remediation of legacy sites. Task Group 105 is making use of case studies of how exposure situations have been managed in the past to provide additional guidance and advice for the protection of non-human biota.

Dose Limits for Man do not Adequately Protect the Ecosystem

DOE Office of Scientific and Technical Information (OSTI.GOV)

Higley, Kathryn A.; Alexakhin, Rudolf M.; McDonald, Joseph C.

2004-08-01

It has been known for quite some time that different organisms display differing degrees of sensitivity to the effects of ionizing radiations. Some microorganisms such as the bacterium Micrococcus radiodurans, along with many species of invertebrates, are extremely radio-resistant. Humans might be categorized as being relatively sensitive to radiation, and are a bit more resistant than some pine trees. Therefore, it could be argued that maintaining the dose limits necessary to protect humans will also result in the protection of most other species of flora and fauna. This concept is usually referred to as the anthropocentric approach. In other words,more » if man is protected then the environment is also adequately protected. The ecocentric approach might be stated as; the health of humans is effectively protected only when the environment is not unduly exposed to radiation. The ICRP is working on new recommendations dealing with the protection of the environment, and this debate should help to highlight a number of relevant issues concerning that topic.« less

Determination of kinetic parameters for 123-I thyroid uptake in healthy Japanese

NASA Astrophysics Data System (ADS)

Kusuhara, Hiroyuki; Maeda, Kazuya

2017-09-01

The purpose of this study was to compare the kinetic parameters for iodide thyroid accumulation in Japanese today with previously reported values. We determined the thyroid uptake of 123-I at 24 hours after the oral administration in healthy male Japanese without any diet restriction. The mean value was 16.1±5.4%, which was similar or rather lower than those previously reported in Japan (1958-1972). Kinetic model analysis was conducted to obtain the clearance for thyroid uptake from the blood circulation. The thyroid uptake clearance of 123-I was 0.540±0.073 ml/min, which was almost similar to those reported previously. There is no obvious difference in the thyroid uptake for 24 hours, and kinetic parameters in healthy Japanese for these 50 years. The fraction of distributed to the thyroid gland is lower than the ICRP reference man, and such difference must be taken into consideration to estimate the radiation exposure upon Fukushima accident in Japan.

Determination of quality factors by microdosimetry

NASA Astrophysics Data System (ADS)

Al-Affan, I. A. M.; Watt, D. E.

1987-03-01

The application of microdose parameters for the specification of a revised scale of quality factors which would be applicable at low doses and dose rates is examined in terms of an original proposal by Rossi. Two important modifications are suggested to enable an absolute scale of quality factors to be constructed. Allowance should be made to allow for the dependence of the saturation threshold of lineal energy on the type of heavy charged particle. Also, an artificial saturation threshold should be introduced for electron tracks as a mean of modifying the measurements made in the microdosimeter to the more realistic site sizes of nanometer dimensions. The proposed absolute scale of quality factors nicely encompasses the high RBEs of around 3 observed at low doses for tritium β rays and is consistent with the recent recommendation of the ICRP that the quality factor for fast neutrons be increased by a factor of two, assuming that there is no biological repair for the reference radiation.

Ageing and the self-reference effect in memory.

PubMed

Gutchess, Angela H; Kensinger, Elizabeth A; Yoon, Carolyn; Schacter, Daniel L

2007-11-01

The present study investigates potential age differences in the self-reference effect. Young and older adults incidentally encoded adjectives by deciding whether the adjective described them, described another person (Experiments 1 & 2), was a trait they found desirable (Experiment 3), or was presented in upper case. Like young adults, older adults exhibited superior recognition for self-referenced items relative to the items encoded with the alternate orienting tasks, but self-referencing did not restore their memory to the level of young adults. Furthermore, the self-reference effect was more limited for older adults. Amount of cognitive resource influenced how much older adults benefit from self-referencing, and older adults appeared to extend the strategy less flexibly than young adults. Self-referencing improves older adults' memory, but its benefits are circumscribed despite the social and personally relevant nature of the task.

Focal role of tolerability and reasonableness in the radiological protection system.

PubMed

Schneider, T; Lochard, J; Vaillant, L

2016-06-01

The concepts of tolerability and reasonableness are at the core of the International Commission on Radiological Protection (ICRP) system of radiological protection. Tolerability allows the definition of boundaries for implementing ICRP principles, while reasonableness contributes to decisions regarding adequate levels of protection, taking into account the prevailing circumstances. In the 1970s and 1980s, attempts to find theoretical foundations in risk comparisons for tolerability and cost-benefit analysis for reasonableness failed. In practice, the search for a rational basis for these concepts will never end. Making a wise decision will always remain a matter of judgement and will depend on the circumstances as well as the current knowledge and past experience. This paper discusses the constituents of tolerability and reasonableness at the heart of the radiological protection system. It also emphasises the increasing role of stakeholder engagement in the quest for tolerability and reasonableness since Publication 103. © The International Society for Prosthetics and Orthotics.

Determination of the solubility and size distribution of radioactive aerosols in the uranium processing plant at NRCN.

PubMed

Kravchik, T; Oved, S; Paztal-Levy, O; Pelled, O; Gonen, R; German, U; Tshuva, A

2008-01-01

Inhalation is the main route of internal exposure to radioactive aerosols in the nuclear industry. To assess the radiation dose from the intake of these aerosols, it is necessary to know their physical (aerodynamic diameter distribution) and chemical (dissolution rate in extracellular lung fluid) characteristics. Air samples were taken from the uranium processing plant at the Nuclear Research Center, Negev. Measurements of aerodynamic diameter distribution using a cascade impactor indicated an average activity median aerodynamic diameter value close to 5 microm, in accordance with the recent recommended values of International Commission on Radiological Protection (ICRP) model. Solubility profiles of these aerosols were determined by performing in vitro solubility tests over 100 d in a simultant solution of the extracellular fluid. The tests indicated that the uranium aerosols should be assigned to an absorption between Types M and S (as defined by the ICRP Publication 66 model).

Analysis of the criteria used by the International Commission on Radiological Protection to justify the setting of numerical protection level values.

PubMed

2006-01-01

This report compiles the various numerical protection level values published by the International Commission on Radiological Protection (ICRP) since its 1990 Recommendations (Publication 60). Several terms are used to denominate the protection levels: individual dose limit, 'maximum' individual dose, dose constraint, exemption level, exclusion level, action level, or intervention level. The reasons provided by the Commission for selecting the associated numerical values is quoted as far as available. In some cases the rationale is not totally explicit in the original ICRP report concerned; in such cases the Task Group that prepared the present report have proposed their own interpretation. Originally, this report was prepared by a Task Group at CEPN, a French research and development center, in behalf of IRSN, a French public expert body engaged in radiological protection and nuclear safety. It is published here with kind permission by CEPN and IRSN.

Impact of the Revised 10 CFR 835 on the Neutron Dose Rates at LLNL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Radev, R

2009-01-13

In June 2007, 10 CFR 835 [1] was revised to include new radiation weighting factors for neutrons, updated dosimetric models, and dose terms consistent with the newer ICRP recommendations. A significant aspect of the revised 10 CFR 835 is the adoption of the recommendations outlined in ICRP-60 [2]. The recommended new quantities demand a review of much of the basic data used in protection against exposure to sources of ionizing radiation. The International Commission on Radiation Units and Measurements has defined a number of quantities for use in personnel and area monitoring [3,4,5] including the ambient dose equivalent H*(d) tomore » be used for area monitoring and instrument calibrations. These quantities are used in ICRP-60 and ICRP-74. This report deals only with the changes in the ambient dose equivalent and ambient dose rate equivalent for neutrons as a result of the implementation of the revised 10 CFR 835. In the report, the terms neutron dose and neutron dose rate will be used for convenience for ambient neutron dose and ambient neutron dose rate unless otherwise stated. This report provides a qualitative and quantitative estimate of how much the neutron dose rates at LLNL will change with the implementation of the revised 10 CFR 835. Neutron spectra and dose rates from selected locations at the LLNL were measured with a high resolution spectroscopic neutron dose rate system (ROSPEC) as well as with a standard neutron rem meter (a.k.a., a remball). The spectra obtained at these locations compare well with the spectra from the Radiation Calibration Laboratory's (RCL) bare californium source that is currently used to calibrate neutron dose rate instruments. The measurements obtained from the high resolution neutron spectrometer and dose meter ROSPEC and the NRD dose meter compare within the range of {+-}25%. When the new radiation weighting factors are adopted with the implementation of the revised 10 CFR 835, the measured dose rates will increase by up to 22%. The health physicists should consider this increase for any areas that have dose rates near a posting limit, such as near the 100 mrem/hr for a high radiation area, as this increase in measured dose rate may result in some changes to postings and consequent radiological controls.« less

Selection and validation of suitable reference genes for miRNA expression normalization by quantitative RT-PCR in citrus somatic embryogenic and adult tissues.

PubMed

Kou, Shu-Jun; Wu, Xiao-Meng; Liu, Zheng; Liu, Yuan-Long; Xu, Qiang; Guo, Wen-Wu

2012-12-01

miRNAs have recently been reported to modulate somatic embryogenesis (SE), a key pathway of plant regeneration in vitro. For expression level detection and subsequent function dissection of miRNAs in certain biological processes, qRT-PCR is one of the most effective and sensitive techniques, for which suitable reference gene selection is a prerequisite. In this study, three miRNAs and eight non-coding RNAs (ncRNA) were selected as reference candidates, and their expression stability was inspected in developing citrus SE tissues cultured at 20, 25, and 30 °C. Stability of the eight non-miRNA ncRNAs was further validated in five adult tissues without temperature treatment. The best single reference gene for SE tissues was snoR14 or snoRD25, while for the adult tissues the best one was U4; although they were not as stable as the optimal multiple references snoR14 + U6 for SE tissues and snoR14 + U5 for adult tissues. For expression normalization of less abundant miRNAs in SE tissues, miR3954 was assessed as a viable reference. Single reference gene snoR14 outperformed multiple references for the overall SE and adult tissues. As one of the pioneer systematic studies on reference gene identification for plant miRNA normalization, this study benefits future exploration on miRNA function in citrus and provides valuable information for similar studies in other higher plants. Three miRNAs and eight non-coding RNAs were tested as reference candidates on developing citrus SE tissues. Best single references snoR14 or snoRD25 and optimal multiple references snoR14 + U6, snoR14 + U5 were identified.

The development of a population of 4D pediatric XCAT phantoms for CT imaging research and optimization

NASA Astrophysics Data System (ADS)

Norris, Hannah; Zhang, Yakun; Frush, Jack; Sturgeon, Gregory M.; Minhas, Anum; Tward, Daniel J.; Ratnanather, J. Tilak; Miller, M. I.; Frush, Donald; Samei, Ehsan; Segars, W. Paul

2014-03-01

With the increased use of CT examinations, the associated radiation dose has become a large concern, especially for pediatrics. Much research has focused on reducing radiation dose through new scanning and reconstruction methods. Computational phantoms provide an effective and efficient means for evaluating image quality, patient-specific dose, and organ-specific dose in CT. We previously developed a set of highly-detailed 4D reference pediatric XCAT phantoms at ages of newborn, 1, 5, 10, and 15 years with organ and tissues masses matched to ICRP Publication 89 values. We now extend this reference set to a series of 64 pediatric phantoms of a variety of ages and height and weight percentiles, representative of the public at large. High resolution PET-CT data was reviewed by a practicing experienced radiologist for anatomic regularity and was then segmented with manual and semi-automatic methods to form a target model. A Multi-Channel Large Deformation Diffeomorphic Metric Mapping (MC-LDDMM) algorithm was used to calculate the transform from the best age matching pediatric reference phantom to the patient target. The transform was used to complete the target, filling in the non-segmented structures and defining models for the cardiac and respiratory motions. The complete phantoms, consisting of thousands of structures, were then manually inspected for anatomical accuracy. 3D CT data was simulated from the phantoms to demonstrate their ability to generate realistic, patient quality imaging data. The population of pediatric phantoms developed in this work provides a vital tool to investigate dose reduction techniques in 3D and 4D pediatric CT.

Optimal weighted combinatorial forecasting model of QT dispersion of ECGs in Chinese adults.

PubMed

Wen, Zhang; Miao, Ge; Xinlei, Liu; Minyi, Cen

2016-07-01

This study aims to provide a scientific basis for unifying the reference value standard of QT dispersion of ECGs in Chinese adults. Three predictive models including regression model, principal component model, and artificial neural network model are combined to establish the optimal weighted combination model. The optimal weighted combination model and single model are verified and compared. Optimal weighted combinatorial model can reduce predicting risk of single model and improve the predicting precision. The reference value of geographical distribution of Chinese adults' QT dispersion was precisely made by using kriging methods. When geographical factors of a particular area are obtained, the reference value of QT dispersion of Chinese adults in this area can be estimated by using optimal weighted combinatorial model and reference value of the QT dispersion of Chinese adults anywhere in China can be obtained by using geographical distribution figure as well.

High resolution, MRI-based, segmented, computerized head phantom

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zubal, I.G.; Harrell, C.R.; Smith, E.O.

1999-01-01

The authors have created a high-resolution software phantom of the human brain which is applicable to voxel-based radiation transport calculations yielding nuclear medicine simulated images and/or internal dose estimates. A software head phantom was created from 124 transverse MRI images of a healthy normal individual. The transverse T2 slices, recorded in a 256x256 matrix from a GE Signa 2 scanner, have isotropic voxel dimensions of 1.5 mm and were manually segmented by the clinical staff. Each voxel of the phantom contains one of 62 index numbers designating anatomical, neurological, and taxonomical structures. The result is stored as a 256x256x128 bytemore » array. Internal volumes compare favorably to those described in the ICRP Reference Man. The computerized array represents a high resolution model of a typical human brain and serves as a voxel-based anthropomorphic head phantom suitable for computer-based modeling and simulation calculations. It offers an improved realism over previous mathematically described software brain phantoms, and creates a reference standard for comparing results of newly emerging voxel-based computations. Such voxel-based computations lead the way to developing diagnostic and dosimetry calculations which can utilize patient-specific diagnostic images. However, such individualized approaches lack fast, automatic segmentation schemes for routine use; therefore, the high resolution, typical head geometry gives the most realistic patient model currently available.« less

46 CFR 160.005-1 - Incorporation by reference.

Code of Federal Regulations, 2014 CFR

2014-10-01

... makes reference to the following documents: (1) Federal Specification: L-P-375C—Plastic Film, Flexible....005-1: (Sheet 1) Cutting Pattern and General Arrangement (Adult). (Sheet 2) Alternate Stitching of Tapes and Webbing (Adult and Child). (Sheet 3) Pad Detail (Adult). (Sheet 4) Cutting Pattern and General...

46 CFR 160.005-1 - Incorporation by reference.

Code of Federal Regulations, 2013 CFR

2013-10-01

... makes reference to the following documents: (1) Federal Specification: L-P-375C—Plastic Film, Flexible....005-1: (Sheet 1) Cutting Pattern and General Arrangement (Adult). (Sheet 2) Alternate Stitching of Tapes and Webbing (Adult and Child). (Sheet 3) Pad Detail (Adult). (Sheet 4) Cutting Pattern and General...

46 CFR 160.005-1 - Incorporation by reference.

Code of Federal Regulations, 2012 CFR

2012-10-01

... makes reference to the following documents: (1) Federal Specification: L-P-375C—Plastic Film, Flexible....005-1: (Sheet 1) Cutting Pattern and General Arrangement (Adult). (Sheet 2) Alternate Stitching of Tapes and Webbing (Adult and Child). (Sheet 3) Pad Detail (Adult). (Sheet 4) Cutting Pattern and General...

46 CFR 160.005-1 - Incorporation by reference.

Code of Federal Regulations, 2011 CFR

2011-10-01

... makes reference to the following documents: (1) Federal Specification: L-P-375C—Plastic Film, Flexible....005-1: (Sheet 1) Cutting Pattern and General Arrangement (Adult). (Sheet 2) Alternate Stitching of Tapes and Webbing (Adult and Child). (Sheet 3) Pad Detail (Adult). (Sheet 4) Cutting Pattern and General...

[Relationship between reference values of fibrinogen and geographical factors based on neural network analysis].

PubMed

Li, Meng-Jiao; Ge, Miao; Wang, Cong-Xia; Cen, Min-Yi; Jiang, Ji-Lin; He, Jin-Wei; Lin, Qian-Yi; Liu, Xin

2016-08-20

To analyze the relationship between the reference values of fibrinogen (FIB) in healthy Chinese adults and geographical factors to provide scientific evidences for establishing the uniform standard. The reference values of FIB of 10701 Chinese healthy adults from 103 cities were collected to investigate their relationship with 18 geographical factors including spatial index, terrain index, climate index, and soil index. Geographical factors that significantly correlated with the reference values were selected for constructing the BP neural network model. The spatial distribution map of the reference value of FIB of healthy Chinese adults was fitted by disjunctive kriging interpolation. We used the 5-layer neural network and selected 2000 times of training covering 11 hidden layers to build the simulation rule for simulating the relationship between FIB and geographical environmental factors using the MATLAB software. s The reference value of FIB in healthy Chinese adults was significantly correlated with the latitude, sunshine duration, annual average temperature, annual average relative humidity, annual precipitation, annual range of air temperature, average annual soil gravel content, and soil cation exchange capacity (silt). The artificial neural networks were created to analyze the simulation of the selected indicators of geographical factors. The spatial distribution map of the reference values of FIB in healthy Chinese adults showed a distribution pattern that FIB levels were higher in the South and lower in the North, and higher in the East and lower in the West. When the geographical factors of a certain area are known, the reference values of FIB in healthy Chinese adults can be obtained by establishing the neural network mode or plotting the spatial distribution map.

[Geographical distribution of the Serum creatinine reference values of healthy adults].

PubMed

Wei, De-Zhi; Ge, Miao; Wang, Cong-Xia; Lin, Qian-Yi; Li, Meng-Jiao; Li, Peng

2016-11-20

To explore the relationship between serum creatinine (Scr) reference values in healthy adults and geographic factors and provide evidence for establishing Scr reference values in different regions. We collected 29 697 Scr reference values from healthy adults measured by 347 medical facilities from 23 provinces, 4 municipalities and 5 autonomous regions. We chose 23 geographical factors and analyzed their correlation with Scr reference values to identify the factors correlated significantly with Scr reference values. According to the Principal component analysis and Ridge regression analysis, two predictive models were constructed and the optimal model was chosen after comparison of the two model's fitting degree of predicted results and measured results. The distribution map of Scr reference values was drawn using the Kriging interpolation method. Seven geographic factors, including latitude, annual sunshine duration, annual average temperature, annual average relative humidity, annual precipitation, annual temperature range and topsoil (silt) cation exchange capacity were found to correlate significantly with Scr reference values. The overall distribution of Scr reference values featured a pattern that the values were high in the south and low in the north, varying consistently with the latitude change. The data of the geographic factors in a given region allows the prediction of the Scr values in healthy adults. Analysis of these geographical factors can facilitate the determination of the reference values specific to a region to improve the accuracy for clinical diagnoses.

Assessing the International Landscape

Cancer.gov

On April 11th, 2018 the NCI Center for Research Strategy, in coordination with CGH, hosted the Annual Meeting of the International Cancer Research Partnership (ICRP). The meeting marked 18 years of a successful partnership, representing 124 organizations that fund cancer research projects in 145 countries.

Clinical-Functional Vulnerability Index-20 (IVCF-20): rapid recognition of frail older adults

PubMed Central

de Moraes, Edgar Nunes; do Carmo, Juliana Alves; de Moraes, Flávia Lanna; Azevedo, Raquel Souza; Machado, Carla Jorge; Montilla, Dalia Elena Romero

2016-01-01

ABSTRACT OBJECTIVE To evaluate the adequacy of the Clinical-Functional Vulnerability Index-20, a rapid triage instrument to test vulnerability in Brazilian older adults, for the use in primary health care. METHODS The study included convenience sample of 397 patients aged older than or equal to 60 years attended at Centro de Referência para o Idoso (Reference Center for Older Adults) and of 52 older adults the same age attended at the community. The results of the questionnaire, consisting of 20 questions, were compared with those of the Comprehensive Geriatric Assessment, considered a reference for identifying frail older adults. Spearman’s correlation was evaluated in the Clinical-Functional Vulnerability Index-20 with the Comprehensive Geriatric Assessment; the validity was verified by the area under the ROC curve; reliability was estimated by the percentage of agreement among evaluators and by the kappa coefficient, both with quadratic weighted. The cut-off point was obtained based on the higher accuracy criterion. Cronbach’s alpha, a measure of internal consistency, was estimated. RESULTS The Spearman’s correlation coefficient was high and positive for both groups (0.792 for older adults attended at the Reference Center and 0.305 for older adults from the community [p < 0.001]). The area under the ROC curve for older adults attended at the Reference Center was substantial (0.903). The cut-off point obtained was six, and older adults with scores in Clinical-Functional Vulnerability Index-20 above that value had strong possibility of being frail. For older adults from the community, the quadratic weighted agreement among evaluators was 99.5%, and the global quadratic weighted kappa coefficient was 0.94. Cronbach’s alpha was high for older adults attended at the Reference Center (0.861) and those attended at the community (0.740). CONCLUSIONS The Clinical-Functional Vulnerability Index-20 questionnaire, in the sample examined, turned out to be positively correlated with the Comprehensive Geriatric Assessment, in addition to the results indicating a high degree of validity and reliability. Thus, the Clinical-Functional Vulnerability Index-20 proves to be viable as a triage instrument in the primary health care that identifies frail older adults (older adults at risk of weakening and frail older adults). PMID:28099667

Radiation dosimetry measurements with real time radiation monitoring device (RRMD)-II in Space Shuttle STS-79

NASA Technical Reports Server (NTRS)

Sakaguchi, T.; Doke, T.; Hayashi, T.; Kikuchi, J.; Hasebe, N.; Kashiwagi, T.; Takashima, T.; Takahashi, K.; Nakano, T.; Nagaoka, S.;

A review of lung-to-blood absorption rates for radon progeny.

PubMed

Marsh, J W; Bailey, M R

2013-12-01

The International Commission on Radiological Protection (ICRP) Publication 66 Human Respiratory Tract Model (HRTM) treats clearance of materials from the respiratory tract as a competitive process between absorption into blood and particle transport to the alimentary tract and lymphatics. The ICRP recommended default absorption rates for lead and polonium (Type M) in ICRP Publication 71 but stated that the values were not appropriate for short-lived radon progeny. This paper reviews and evaluates published data from volunteer and laboratory animal experiments to estimate the HRTM absorption parameter values for short-lived radon progeny. Animal studies showed that lead ions have two phases of absorption: ∼10 % absorbed with a half-time of ∼15 min, the rest with a half-time of ∼10 h. The studies also indicated that some of the lead ions were bound to respiratory tract components. Bound fractions, f(b), for lead were estimated from volunteer and animal studies and ranged from 0.2 to 0.8. Based on the evaluations of published data, the following HRTM absorption parameter values were derived for lead as a decay product of radon: f(r) = 0.1, s(r) = 100 d(-1), s(s) = 1.7 d(-1), f(b) = 0.5 and s(b) = 1.7 d(-1). Effective doses calculated assuming these absorption parameter values instead of a single absorption half-time of 10 h with no binding (as has generally been assumed) are only a few per cent higher. However, as there is some conflicting evidence on the absorption kinetics for radon progeny, dose calculations have been carried out for different sets of absorption parameter values derived from different studies. The results of these calculations are discussed.

Occupational radiation dose to eyes from endoscopic retrograde cholangiopancreatography procedures in light of the revised eye lens dose limit from the International Commission on Radiological Protection.

PubMed

O'Connor, U; Gallagher, A; Malone, L; O'Reilly, G

2013-02-01

Endoscopic retrograde cholangiopancreatography (ERCP) is a common procedure that combines the use of X-ray fluoroscopy and endoscopy for examination of the bile duct. Published data on ERCP doses are limited, including staff eye dose from ERCP. Occupational eye doses are of particular interest now as the International Commission on Radiological Protection (ICRP) has recommended a reduction in the dose limit to the lens of the eye. The aim of this study was to measure occupational eye doses obtained from ERCP procedures. A new eye lens dosemeter (EYE-D(™), Radcard, Krakow, Poland) was used to measure the ERCP eye dose, H(p)(3), at two endoscopy departments in Ireland. A review of radiation protection practice at the two facilities was also carried out. The mean equivalent dose to the lens of the eye of a gastroenterologist is 0.01 mSv per ERCP procedure with an undercouch X-ray tube and 0.09 mSv per ERCP procedure with an overcouch X-ray tube. Staff eye dose normalised to patient kerma area product is also presented. Staff eye doses in ERCP have the potential to exceed the revised ICRP limit of 20 mSv per annum when an overcouch X-ray tube is used. The EYE-D dosemeter was found to be a convenient method for measuring lens dose. Eye doses in areas outside of radiology departments should be kept under review, particularly in light of the new ICRP eye dose limit. Occupational eye lens doses from ERCP procedures have been established using a new commercially available dedicated H(p)(3) dosemeter.

Radiological Risk Assessment of Capstone Depleted Uranium Aerosols

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hahn, Fletcher; Roszell, Laurie E.; Daxon, Eric G.

2009-02-26

Assessment of the health risk from exposure to aerosols of depleted uranium (DU) is an important outcome of the Capstone aerosol studies that established exposure ranges to personnel in armored combat vehicles perforated by DU munitions. Although the radiation exposure from DU is low, there is concern that DU deposited in the body may increase cancer rates. Radiation doses to various organs of the body resulting from the inhalation of DU aerosols measured in the Capstone studies were calculated using International Commission on Radiological Protection (ICRP) models. Organs and tissues with the highest calculated committed equivalent 50-yr doses were lungmore » and extrathoracic tissues (nose and nasal passages, pharynx, larynx, mouth and thoracic lymph nodes). Doses to the bone surface and kidney were about 5 to 10% of the doses to the extrathoracic tissues. The methodologies of the ICRP International Steering Committee on Radiation Standards (ISCORS) were used for determining the whole body cancer risk. Organ-specific risks were estimated using ICRP and U.S. Environmental Protection Agency (EPA) methodologies. Risks for crewmembers and first responders were determined for selected scenarios based on the time interval of exposure and for vehicle and armor type. The lung was the organ with the highest cancer mortality risk, accounting for about 97% of the risks summed from all organs. The highest mean lifetime risk for lung cancer for the scenario with the longest exposure time interval (2 h) was 0.42%. This risk is low compared with the natural or background risk of 7.35%. These risks can be significantly reduced by using an existing ventilation system (if operable) and by reducing personnel time in the vehicle immediately after perforation.« less

Integrating cognitive rehabilitation: A preliminary program description and theoretical review of an interdisciplinary cognitive rehabilitation program.

PubMed

Fleeman, Jennifer A; Stavisky, Christopher; Carson, Simon; Dukelow, Nancy; Maier, Sheryl; Coles, Heather; Wager, John; Rice, Jordyn; Essaff, David; Scherer, Marcia

2015-01-01

Interdisciplinary cognitive rehabilitation is emerging as the expected standard of care for individuals with mild to moderate degrees of cognitive impairment for a variety of etiologies. There is a growing body of evidence in cognitive rehabilitation literature supporting the involvement of multiple disciplines, with the use of cognitive support technologies (CSTs), in delivering cognitive therapy to individuals who require cognitive rehabilitative therapies. This article provides an overview of the guiding theories related to traditional approaches of cognitive rehabilitation and the positive impact of current theoretical models of an interdisciplinary approach in clinical service delivery of this rehabilitation. A theoretical model of the Integrative Cognitive Rehabilitation Program (ICRP) will be described in detail along with the practical substrates of delivering specific interventions to individuals and caregivers who are living with mild to moderate cognitive impairment. The ultimate goal of this article is to provide a clinically useful resource for direct service providers. It will serve to further clinical knowledge and understanding of the evolution from traditional silo based treatment paradigms to the current implementation of multiple perspectives and disciplines in the pursuit of patient centered care. The article will discuss the theories that contributed to the development of the interdisciplinary team and the ICRP model, implemented with individuals with mild to moderate cognitive deficits, regardless of etiology. The development and implementation of specific assessment and intervention strategies in this cognitive rehabilitation program will also be discussed. The assessment and intervention strategies utilized as part of ICRP are applicable to multiple clinical settings in which individuals with cognitive impairment are served. This article has specific implications for rehabilitation which include: (a) An Interdisciplinary Approach is an effective method for cognitive rehabilitation; and (b) Recent theories offer beneficial evaluation and intervention techniques for cognitive rehabilitation.

Occupational radiation dose to eyes from interventional radiology procedures in light of the new eye lens dose limit from the International Commission on Radiological Protection

PubMed Central

Walsh, C; Gallagher, A; Dowling, A; Guiney, M; Ryan, J M; McEniff, N; O'Reilly, G

2015-01-01

Objective: In 2011, the International Commission on Radiological Protection (ICRP) recommended a substantial reduction in the equivalent dose limit for the lens of the eye, in line with a reduced threshold of absorbed dose for radiation-induced cataracts. This is of particular relevance in interventional radiology (IR) where it is well established that staff doses can be significant, however, there is a lack of data on IR eye doses in terms of Hp(3). Hp(3) is the personal dose equivalent at a depth of 3 mm in soft tissue and is used for measuring lens dose. We aimed to obtain a reliable estimate of eye dose to IR operators. Methods: Lens doses were measured for four interventional radiologists over a 3-month period using dosemeters specifically designed to measure Hp(3). Results: Based on their typical workloads, two of the four interventional radiologists would exceed the new ICRP dose limit with annual estimated doses of 31 and 45 mSv to their left eye. These results are for an “unprotected” eye, and for IR staff who routinely wear lead glasses, the dose beneath the glasses is likely to be significantly lower. Staff eye dose normalized to patient kerma–area product and eye dose per procedure have been included in the analysis. Conclusion: Eye doses to IR operators have been established using a dedicated Hp(3) dosemeter. Estimated annual doses have the potential to exceed the new ICRP limit. Advances in knowledge: We have estimated lens dose to interventional radiologists in terms of Hp(3) for the first time in an Irish hospital setting. PMID:25761211

Uranium analysis in some food samples collected from Bathinda area of Punjab, India

NASA Astrophysics Data System (ADS)

Kumar, Mukesh; Prasher, Sangeeta; Singh, Surinder

2009-07-01

To strengthen the radiation protection infrastructure in Bathinda, the uranium concentration in daily diet of the residents has been measured and its associated radiation risks were estimated for the adult population. Food samples were collected from major cancer prone areas of the district, from which daily diets were prepared. These diet samples were analyzed using fission track technique. The measured values of the uranium content were found to vary from 0.38 mBq/g in mustard seeds to 4.60 mBq/g in wheat. In case of milk the uranium content is found to vary from 28.57-213.36 mBq/ℓ with mean concentration of 61.35 mBq/ℓ. This leads to a daily dietary intake of 0.90 Bq/day. The measured value of 0.90 Bq d-1, contributes to 1.12 mSv to the cumulative effective dose to the population. This dose is much large than the International Commission for Radiological Protection (ICRP) annual effective dose limit of 1 mSv for the general public [1]. Therefore, it would pose significant health hazard.

Two-year-olds exclude novel objects as potential referents of novel words based on pragmatics.

PubMed

Grassmann, Susanne; Stracke, Marén; Tomasello, Michael

2009-09-01

Many studies have established that children tend to exclude objects for which they already have a name as potential referents of novel words. In the current study we asked whether this exclusion can be triggered by social-pragmatic context alone without pre-existing words as blockers. Two-year-old children watched an adult looking at a novel object while saying a novel word with excitement. In one condition the adult had not seen the object beforehand, and so the children interpreted the adult's utterance as referring to the gazed-at object. In another condition the adult and child had previously played jointly with the gazed-at object. In this case, children less often assumed that the adult was referring to the object but rather they searched for an alternative referent--presumably because they inferred that the gazed-at object was old news in their common ground with the adult and so not worthy of excited labeling. Since this inference based on exclusion is highly similar to that underlying the Principle of Contrast/Mutual Exclusivity, we propose that this principle is not purely lexical but rather is based on children's understanding of how and why people direct one another's attention to things either with or without language.

TestDose: A nuclear medicine software based on Monte Carlo modeling for generating gamma camera acquisitions and dosimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garcia, Marie-Paule, E-mail: marie-paule.garcia@univ-brest.fr; Villoing, Daphnée; McKay, Erin

Purpose: The TestDose platform was developed to generate scintigraphic imaging protocols and associated dosimetry by Monte Carlo modeling. TestDose is part of a broader project (www.dositest.com) whose aim is to identify the biases induced by different clinical dosimetry protocols. Methods: The TestDose software allows handling the whole pipeline from virtual patient generation to resulting planar and SPECT images and dosimetry calculations. The originality of their approach relies on the implementation of functional segmentation for the anthropomorphic model representing a virtual patient. Two anthropomorphic models are currently available: 4D XCAT and ICRP 110. A pharmacokinetic model describes the biodistribution of amore » given radiopharmaceutical in each defined compartment at various time-points. The Monte Carlo simulation toolkit GATE offers the possibility to accurately simulate scintigraphic images and absorbed doses in volumes of interest. The TestDose platform relies on GATE to reproduce precisely any imaging protocol and to provide reference dosimetry. For image generation, TestDose stores user’s imaging requirements and generates automatically command files used as input for GATE. Each compartment is simulated only once and the resulting output is weighted using pharmacokinetic data. Resulting compartment projections are aggregated to obtain the final image. For dosimetry computation, emission data are stored in the platform database and relevant GATE input files are generated for the virtual patient model and associated pharmacokinetics. Results: Two samples of software runs are given to demonstrate the potential of TestDose. A clinical imaging protocol for the Octreoscan™ therapeutical treatment was implemented using the 4D XCAT model. Whole-body “step and shoot” acquisitions at different times postinjection and one SPECT acquisition were generated within reasonable computation times. Based on the same Octreoscan™ kinetics, a dosimetry computation performed on the ICRP 110 model is also presented. Conclusions: The proposed platform offers a generic framework to implement any scintigraphic imaging protocols and voxel/organ-based dosimetry computation. Thanks to the modular nature of TestDose, other imaging modalities could be supported in the future such as positron emission tomography.« less

TestDose: A nuclear medicine software based on Monte Carlo modeling for generating gamma camera acquisitions and dosimetry.

PubMed

Garcia, Marie-Paule; Villoing, Daphnée; McKay, Erin; Ferrer, Ludovic; Cremonesi, Marta; Botta, Francesca; Ferrari, Mahila; Bardiès, Manuel

2015-12-01

The TestDose platform was developed to generate scintigraphic imaging protocols and associated dosimetry by Monte Carlo modeling. TestDose is part of a broader project (www.dositest.com) whose aim is to identify the biases induced by different clinical dosimetry protocols. The TestDose software allows handling the whole pipeline from virtual patient generation to resulting planar and SPECT images and dosimetry calculations. The originality of their approach relies on the implementation of functional segmentation for the anthropomorphic model representing a virtual patient. Two anthropomorphic models are currently available: 4D XCAT and ICRP 110. A pharmacokinetic model describes the biodistribution of a given radiopharmaceutical in each defined compartment at various time-points. The Monte Carlo simulation toolkit gate offers the possibility to accurately simulate scintigraphic images and absorbed doses in volumes of interest. The TestDose platform relies on gate to reproduce precisely any imaging protocol and to provide reference dosimetry. For image generation, TestDose stores user's imaging requirements and generates automatically command files used as input for gate. Each compartment is simulated only once and the resulting output is weighted using pharmacokinetic data. Resulting compartment projections are aggregated to obtain the final image. For dosimetry computation, emission data are stored in the platform database and relevant gate input files are generated for the virtual patient model and associated pharmacokinetics. Two samples of software runs are given to demonstrate the potential of TestDose. A clinical imaging protocol for the Octreoscan™ therapeutical treatment was implemented using the 4D XCAT model. Whole-body "step and shoot" acquisitions at different times postinjection and one SPECT acquisition were generated within reasonable computation times. Based on the same Octreoscan™ kinetics, a dosimetry computation performed on the ICRP 110 model is also presented. The proposed platform offers a generic framework to implement any scintigraphic imaging protocols and voxel/organ-based dosimetry computation. Thanks to the modular nature of TestDose, other imaging modalities could be supported in the future such as positron emission tomography.

THE SCIENCE BEHIND THE ICRP 2005 RECOMMENDATIONS

EPA Science Inventory

The ICRP 2005 Recommendations are stated to be "based on a simple, but widely applicable, general system of protection that will clarify its objectives and will provide a basis for the more formal systems needed by operating managements and regulators". The Recommendati...

The optimisation of occupational potential exposures - preliminary considerations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crouail, P.; Guimaraes, L.

1995-03-01

One of the major innovation brought about the ICRP 60 recommendations and emphasized by the ICRP 64 publication, is the introduction of the concept of potential exposures into the system of radiological protection. Potential exposures are characterized by {open_quotes}probability of occurrence lesser than unity{close_quotes} and {open_quotes}radiological risks exceeding normal levels{close_quotes} where normal must be interpreted as not exceeding the planned routine exposures. It is then necessary to develop consensual methods to look for and choose the optimum scenarios (i.e. those for which probability of events and possible consequences have been reduced as low as reasonably achievable). Moreover, the boundaries formore » the unacceptable levels of risks for workers should be defined, as well as reasonable risk indicators. The aim of this paper is to discuss the actual changes in the field of occupational radiological protection, induced by the potential exposure concept with particular emphasize on the optimization of protection.« less

Calculated organ doses for Mayak production association central hall using ICRP and MCNP.

PubMed

Choe, Dong-Ok; Shelkey, Brenda N; Wilde, Justin L; Walk, Heidi A; Slaughter, David M

2003-03-01

As part of an ongoing dose reconstruction project, equivalent organ dose rates from photons and neutrons were estimated using the energy spectra measured in the central hall above the graphite reactor core located in the Russian Mayak Production Association facility. Reconstruction of the work environment was necessary due to the lack of personal dosimeter data for neutrons in the time period prior to 1987. A typical worker scenario for the central hall was developed for the Monte Carlo Neutron Photon-4B (MCNP) code. The resultant equivalent dose rates for neutrons and photons were compared with the equivalent dose rates derived from calculations using the conversion coefficients in the International Commission on Radiological Protection Publications 51 and 74 in order to validate the model scenario for this Russian facility. The MCNP results were in good agreement with the results of the ICRP publications indicating the modeling scenario was consistent with actual work conditions given the spectra provided. The MCNP code will allow for additional orientations to accurately reflect source locations.

Radiological Protection Issues Arising During and After the Fukushima Nuclear Reactor Accident-Memorandum of TG 84 of ICRP.

PubMed

Weiss, Wolfgang

2016-09-01

Observations and lessons identified after the Fukushima accident have been collected and assessed by ICRP Task Group 84. Together with the observations of other expert organizations, they are being used to further develop the current system of protection. While many of the established protection criteria remain valid, improvements are needed in three areas. Key issues related to the need of planning for long-term protective actions (criteria for returning home, dealing with waste) have to be implemented as important elements of the national protection strategies during the preparedness stage. The justification of disruptive protective actions and the protection of vulnerably groups of the population need to be reconsidered to avoid unpleasant imbalances and outcomes. The coexistence of radiation-induced health effects and health effects with social determinants requires consideration of both aspects in decision-making and response. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Human absorption and retention of polonium-210 from caribou meat.

PubMed

Thomas, P A; Fisenne, I; Chorney, D; Baweja, A S; Tracy, B L

2001-01-01

The gastrointestinal (GI) absorption factors and the biological retention times for polonium were determined for a group of 14 volunteers--seven men and seven women--from Saskatoon, Saskatchewan, Canada. Each volunteer consumed 2.0 kg of caribou meat containing known amounts of naturally occurring 210Po. Urine and faecal samples were collected for up to 65 days after meat consumption and analysed for 210Po. The average GI absorption factor for the 14 volunteers was 56 +/- 4% (range = 31-71%), not significantly different from the ICRP value of 50%. About 3% of absorbed polonium underwent prompt excretion by the urinary pathway. The remainder was retained by the body with a half-time >100 days, compared to the ICRP value of 50 days. The effect of these findings increases the dose estimate for ingestion of 210Po in food by a factor of 1.5 to 3.5. Thus, background doses to people consuming caribou and reindeer may be higher than previously thought.

Radiation protection of people and the environment: developing a common approach.

PubMed

Pentreath, R J

2002-03-01

The problem with the current ICRP system of radiation protection, particularly for regulators, is that it fails to differentiate between the application of justification and optimisation to people in the circumstances of medical care or as part of a workforce, compared with their application to members of the general public in an environmental setting; plus the fact that it also fails to address the issue of potential impacts on the rest of the environment in any meaningful way. But if these deficiencies are to be addressed, it will be essential to consider how protection of both people and the living environment can be achieved within a broad philosophical framework, using complementary approaches, based on the same underlying scientific knowledge. This paper briefly examines some of these issues, and offers some suggestions for developing a common, or even a combined, approach. It draws upon recent suggestions made by the ICRP itself with regard to radiological protection, plus current activities-on several fronts-to provide an explicit basis for environmental protection.

Similarity to the Self Affects Memory for Impressions of Others in Younger and Older Adults

PubMed Central

Park, Jung M.; Gutchess, Angela H.

2015-01-01

Objectives. Similarity to the self has been shown to affect memory for impressions in younger adults, suggesting a self-reference effect in person memory. Because older adults show comparable self-reference effects, but prioritize memory for positive over negative information relative to young adults, we examined age differences in self-similarity effects on memory for positive and negative impressions. Method. Younger and older adults formed positive and negative impressions of others differing in the degree of similarity to the self (high, medium, low). Results. For positive impressions, both groups showed enhanced memory for self-similar others relative to dissimilar others, whereas for negative impressions, memory was poorer for those similar to the self. When collapsed across similarity to the self, younger adults remembered negative impressions better than older adults, but interestingly, older adults exhibited a trend for better memory for the positive impressions. Discussion. Results suggest that self-reference effects in impression memory are preserved with age and that older adults exhibit positivity effects in person memory consistent with previous findings. PMID:24389124

Lung-clearance classification of radionuclides in calcined phosphate rock dust

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kalkwarf, D.R.; Jackson, P.O.

1984-08-01

Lung-clearance classifications for /sup 210/Pb and /sup 210/Po in airborne dust from elemental phosphorus plants were estimated for use with the lung clearance model proposed by the ICRP Task Group on Lung Dynamics. Estimates were based on measurements of dissolution rates for these radionuclides from sized dust samples into simulated lung fluid at 37/sup 0/C. The estimates were expressed in the classification terms of the model, i.e., D, W and Y, indicating lung clearance half-times of 0 to 10 days, 11 to 100 days and more than 100 days. Dust samples were obtained from two plants in the western Unitedmore » States, and dissolution trials were conducted on fractions containing particles with aerodynamic equivalent diameters (AED) of 0 to 3 ..mu..m and of 3 to 10 ..mu..m. The /sup 210/Pb and /sup 210/Po in each of these fractions were classified 100% Class Y. The specific activities of both radionuclides increased with decreasing AED of the particles. 11 references, 1 figure, 4 tables.« less

Natural radioactivity and radon exhalation rates in man-made tiles used as building materials in Japan.

PubMed

Iwaoka, K; Hosoda, M; Suwankot, N; Omori, Y; Ishikawa, T; Yonehara, H; Tokonami, S

2015-11-01

Man-made tiles frequently used in Japan were collected, and activity concentrations and radon ((222)Rn) exhalation rates in these tiles were measured. Dose estimations for inhabitants living in houses built using these tiles were also carried out. The activity concentrations of (226)Ra, (228)Ra and (40)K in the man-made tiles were 31-170, 35-110 and 260-980 Bq kg(-1), respectively. The (222)Rn exhalation rates in the tiles were 8.8-21 μBq m(-2) s(-1). The ranges of experimental activity concentrations and (222)Rn exhalation rates were almost identical to those of natural rocks used as typical building materials in Japan. The maximum value of effective dose to inhabitants living in houses built with the man-made tiles was 0.14 mSv y(-1), which is lower than the reference level range (1-20 mSv y(-1)) for abnormally high levels of natural background radiation published in the ICRP Publication 103. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Methods to improve routine bioassay monitoring for freshly separated, poorly transported plutonium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bihl, D.E.; Lynch, T.P.; Carbaugh, E.H.

1988-09-01

Several human cases involving inhalation of plutonium oxide at Hanford have shown clearance half-times from the lung that are much longer than the 500-day half-time recommended for class Y plutonium in Publication 30 of the International Commission on Radiological Protection(ICRP). The more tenaciously retained material is referred to as super class Y plutonium. The ability to detect super class Y plutonium by current routine bioassay measurements is shown to be poor. Pacific Northwest Laboratory staff involved in the Hanford Internal Dosimetry Program investigated four methods to se if improvements in routine monitoring of workers for fresh super class Y plutoniummore » are feasible. The methods were lung counting, urine sampling, fecal sampling, and use of diethylenetriaminepentaacetate (DTPA) to enhance urinary excretion. Use of DTPA was determined to be not feasible. Routine fecal sampling was found to be feasible but not recommended. Recommendations were made to improve the detection level for routine annual urinalysis and routine annual lung counting. 12 refs., 9 figs., 7 tabs.« less

Services for Older Adults. Reference Book [and] Student Activity Book.

ERIC Educational Resources Information Center

Texas Tech Univ., Lubbock. Curriculum Center for Family and Consumer Sciences.

This student activity book and reference book, which are part of a family and consumer sciences education series focusing on a broad range of employment opportunities, are intended for use in 1- and 2- programs preparing Texas high school students for employment in occupations related to providing services for older adults. The reference book…

Radiological protection issues arising during and after the Fukushima nuclear reactor accident.

PubMed

González, Abel J; Akashi, Makoto; Boice, John D; Chino, Masamichi; Homma, Toshimitsu; Ishigure, Nobuhito; Kai, Michiaki; Kusumi, Shizuyo; Lee, Jai-Ki; Menzel, Hans-Georg; Niwa, Ohtsura; Sakai, Kazuo; Weiss, Wolfgang; Yamashita, Shunichi; Yonekura, Yoshiharu

2013-09-01

Following the Fukushima accident, the International Commission on Radiological Protection (ICRP) convened a task group to compile lessons learned from the nuclear reactor accident at the Fukushima Daiichi nuclear power plant in Japan, with respect to the ICRP system of radiological protection. In this memorandum the members of the task group express their personal views on issues arising during and after the accident, without explicit endorsement of or approval by the ICRP. While the affected people were largely protected against radiation exposure and no one incurred a lethal dose of radiation (or a dose sufficiently large to cause radiation sickness), many radiological protection questions were raised. The following issues were identified: inferring radiation risks (and the misunderstanding of nominal risk coefficients); attributing radiation effects from low dose exposures; quantifying radiation exposure; assessing the importance of internal exposures; managing emergency crises; protecting rescuers and volunteers; responding with medical aid; justifying necessary but disruptive protective actions; transiting from an emergency to an existing situation; rehabilitating evacuated areas; restricting individual doses of members of the public; caring for infants and children; categorising public exposures due to an accident; considering pregnant women and their foetuses and embryos; monitoring public protection; dealing with 'contamination' of territories, rubble and residues and consumer products; recognising the importance of psychological consequences; and fostering the sharing of information. Relevant ICRP Recommendations were scrutinised, lessons were collected and suggestions were compiled. It was concluded that the radiological protection community has an ethical duty to learn from the lessons of Fukushima and resolve any identified challenges. Before another large accident occurs, it should be ensured that inter alia: radiation risk coefficients of potential health effects are properly interpreted; the limitations of epidemiological studies for attributing radiation effects following low exposures are understood; any confusion on protection quantities and units is resolved; the potential hazard from the intake of radionuclides into the body is elucidated; rescuers and volunteers are protected with an ad hoc system; clear recommendations on crisis management and medical care and on recovery and rehabilitation are available; recommendations on public protection levels (including infant, children and pregnant women and their expected offspring) and associated issues are consistent and understandable; updated recommendations on public monitoring policy are available; acceptable (or tolerable) 'contamination' levels are clearly stated and defined; strategies for mitigating the serious psychological consequences arising from radiological accidents are sought; and, last but not least, failures in fostering information sharing on radiological protection policy after an accident need to be addressed with recommendations to minimise such lapses in communication.

Development of 3D Advanced Rapid Prototyping Multipurpose Structures with Micro and Nano Materials

DTIC Science & Technology

2006-05-01

dynamic parts, cinematic behavior, geometric evaluation, quality and reliability). The RP elements produced normally are moulds (for metal casting but...rapid tooling from Stereo Lithography”, Proceedings of the Seventh International ICRP Conference, California, USA, 9–12 March 1997, pp. 338–354 [5] P

National and State Attitudes of US Adults Toward Tobacco-Free School Grounds, 2009-2010.

PubMed

Kruger, Judy; Patel, Roshni; Kegler, Michelle C; Brener, Nancy D; King, Brian A

2015-12-31

Schools are an important environment for addressing tobacco use among youth. Tobacco-free school policies can help reduce the social acceptability of tobacco use and prevent tobacco initiation among youth. This study assessed attitudes toward tobacco-free school grounds among US adults. Data came from the 2009-2010 National Adult Tobacco Survey, a telephone survey of adults aged 18 or older in the 50 US states and District of Columbia. Respondents were considered to have a favorable attitude toward tobacco-free school grounds if they reported tobacco use should be completely banned on school grounds, including fields and parking lots, and at all school events. Data were assessed using descriptive statistics and multivariable logistic regression, overall and by tobacco use status. Correlates were sex, age, race/ethnicity, education, marital status, income, sexual orientation, US region, and whether respondent lived with any children aged 17 years or younger. Nationally, 86.1% of adults had a favorable attitude toward tobacco-free school grounds, with larger percentages among nontobacco users (91.9%) than current users (76.1%). State prevalence ranged from 80.0% (Kentucky) to 90.9% (Washington). Overall odds of favorable attitudes were higher among nontobacco users (referent, current users), women (referent, men), and adults aged 25 or older (referent, aged 18-24); odds were lower among residents of the South (referent, West) and lesbian, gay, bisexual, or transgender adults (referent, heterosexual or straight). Nearly 9 in 10 US adults have a favorable attitude toward tobacco-free school grounds, but attitudes vary across states and subpopulations. Opportunities exist to educate the public about the benefits of tobacco-free school grounds, which might help reduce tobacco use among youth.

Biochemical marker reference values across pediatric, adult, and geriatric ages: establishment of robust pediatric and adult reference intervals on the basis of the Canadian Health Measures Survey.

PubMed

Adeli, Khosrow; Higgins, Victoria; Nieuwesteeg, Michelle; Raizman, Joshua E; Chen, Yunqi; Wong, Suzy L; Blais, David

2015-08-01

Biological covariates such as age and sex can markedly influence biochemical marker reference values, but no comprehensive study has examined such changes across pediatric, adult, and geriatric ages. The Canadian Health Measures Survey (CHMS) collected comprehensive nationwide health information and blood samples from children and adults in the household population and, in collaboration with the Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER), examined biological changes in biochemical markers from pediatric to geriatric age, establishing a comprehensive reference interval database for routine disease biomarkers. The CHMS collected health information, physical measurements, and biosamples (blood and urine) from approximately 12 000 Canadians aged 3-79 years and measured 24 biochemical markers with the Ortho Vitros 5600 FS analyzer or a manual microplate. By use of CLSI C28-A3 guidelines, we determined age- and sex-specific reference intervals, including corresponding 90% CIs, on the basis of specific exclusion criteria. Biochemical marker reference values exhibited dynamic changes from pediatric to geriatric age. Most biochemical markers required some combination of age and/or sex partitioning. Two or more age partitions were required for all analytes except bicarbonate, which remained constant throughout life. Additional sex partitioning was required for most biomarkers, except bicarbonate, total cholesterol, total protein, urine iodine, and potassium. Understanding the fluctuations in biochemical markers over a wide age range provides important insight into biological processes and facilitates clinical application of biochemical markers to monitor manifestation of various disease states. The CHMS-CALIPER collaboration addresses this important evidence gap and allows the establishment of robust pediatric and adult reference intervals. © 2015 American Association for Clinical Chemistry.

Normative reference values for strength and flexibility of 1,000 children and adults.

PubMed

McKay, Marnee J; Baldwin, Jennifer N; Ferreira, Paulo; Simic, Milena; Vanicek, Natalie; Burns, Joshua

2017-01-03

To establish reference values for isometric strength of 12 muscle groups and flexibility of 13 joint movements in 1,000 children and adults and investigate the influence of demographic and anthropometric factors. A standardized reliable protocol of hand-held and fixed dynamometry for isometric strength of ankle, knee, hip, elbow, and shoulder musculature as well as goniometry for flexibility of the ankle, knee, hip, elbow, shoulder, and cervical spine was performed in an observational study investigating 1,000 healthy male and female participants aged 3-101 years. Correlation and multiple regression analyses were performed to identify factors independently associated with strength and flexibility of children, adolescents, adults, and older adults. Normative reference values of 25 strength and flexibility measures were generated. Strong linear correlations between age and strength were identified in the first 2 decades of life. Muscle strength significantly decreased with age in older adults. Regression modeling identified increasing height as the most significant predictor of strength in children, higher body mass in adolescents, and male sex in adults and older adults. Joint flexibility gradually decreased with age, with little sex difference. Waist circumference was a significant predictor of variability in joint flexibility in adolescents, adults, and older adults. Reference values and associated age- and sex-stratified z scores generated from this study can be used to determine the presence and extent of impairments associated with neuromuscular and other neurologic disorders, monitor disease progression over time in natural history studies, and evaluate the effect of new treatments in clinical trials. © 2016 American Academy of Neurology.

Abnormal glomerular filtration rate in children, adolescents and young adults starts below 75 mL/min/1.73 m(2).

PubMed

Pottel, Hans; Hoste, Liesbeth; Delanaye, Pierre

2015-05-01

The chronic kidney disease (CKD) classification system for children is similar to that for adults, with both mainly based on estimated glomerular filtration rate (eGFR) combined with fixed cut-off values. The main cut-off eGFR value used to define CKD is 60 mL/min/1.73 m(2), a value that is also applied for children older than 2 years of age, adolescents and young adults. Based on a literature search, we evaluated inclusion criteria for eGFR in clinical trials or research studies on CKD for children. We also collected information on direct measurements of GFR (mGFR) in children and adolescents, with the aim to estimate the normal reference range for GFR. Using serum creatinine (Scr) normal reference values and Scr-based eGFR-equations, we also evaluated the correspondence between Scr normal reference values and (e)GFR normal reference values. Based on our literature search, the inclusion of children in published CKD studies has been based on cut-off values for eGFR of >60 mL/min/1.73 m(2). The lower reference limits for mGFR far exceed this adult threshold. Using eGFR values calculated using Scr-based formulas, we found that abnormal Scr levels in children already correspond to eGFR values that are below a cut-off of 75 mL/min/1.73 m(2). Abnormal GFR in children, adolescents and young adults starts below 75 mL/min/1.73 m(2), and as abnormality is a sign of disease, we recommend referring children, adolescents and young adults with an (e)GFR of <75 mL/min/1.73 m(2) for further clinical assessment.

Reference Values for Cardiac and Aortic Magnetic Resonance Imaging in Healthy, Young Caucasian Adults.

PubMed

Eikendal, Anouk L M; Bots, Michiel L; Haaring, Cees; Saam, Tobias; van der Geest, Rob J; Westenberg, Jos J M; den Ruijter, Hester M; Hoefer, Imo E; Leiner, Tim

2016-01-01

Reference values for morphological and functional parameters of the cardiovascular system in early life are relevant since they may help to identify young adults who fall outside the physiological range of arterial and cardiac ageing. This study provides age and sex specific reference values for aortic wall characteristics, cardiac function parameters and aortic pulse wave velocity (PWV) in a population-based sample of healthy, young adults using magnetic resonance (MR) imaging. In 131 randomly selected healthy, young adults aged between 25 and 35 years (mean age 31.8 years, 63 men) of the general-population based Atherosclerosis-Monitoring-and-Biomarker-measurements-In-The-YOuNg (AMBITYON) study, descending thoracic aortic dimensions and wall thickness, thoracic aortic PWV and cardiac function parameters were measured using a 3.0T MR-system. Age and sex specific reference values were generated using dedicated software. Differences in reference values between two age groups (25-30 and 30-35 years) and both sexes were tested. Aortic diameters and areas were higher in the older age group (all p<0.007). Moreover, aortic dimensions, left ventricular mass, left and right ventricular volumes and cardiac output were lower in women than in men (all p<0.001). For mean and maximum aortic wall thickness, left and right ejection fraction and aortic PWV we did not observe a significant age or sex effect. This study provides age and sex specific reference values for cardiovascular MR parameters in healthy, young Caucasian adults. These may aid in MR guided pre-clinical identification of young adults who fall outside the physiological range of arterial and cardiac ageing.

Establishment of new complete blood count reference values for healthy Thai adults.

PubMed

Wongkrajang, P; Chinswangwatanakul, W; Mokkhamakkun, C; Chuangsuwanich, N; Wesarachkitti, B; Thaowto, B; Laiwejpithaya, S; Komkhum, O

2018-04-28

Laboratory reference ranges are essential for diagnostic orientation and treatment decision. As complete blood count parameters are influenced by various factors, including gender, geographic origin, and ethnic origin, it is important to establish specific hematologic reference values for specific populations. This study was conducted at the Department of Clinical Pathology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand. Blood samples were taken from healthy adults aged 18-60 years that attended a health check-up program at our hospital during February 2015 to July 2015. Hematologic and routine chemistry analysis were performed. Participants were determined to be healthy based on medical history and routine medical examinations. Serum vitamin B12, folate, ferritin, and hemoglobin typing were also analyzed to exclude the possible presence of anemia. A statistically significant difference was observed between males and females for Hb level, hematocrit level, red blood cell count, mean corpuscular hemoglobin concentration, percentage neutrophils, monocytes and eosinophils, and absolute neutrophil, lymphocyte, basophil, and platelet counts. Accordingly, gender-specific reference intervals were established for all complete blood count parameters in healthy Thai adult population. The reference value ranges established in this study reflect significant differences between genders. It is possible that these reference ranges may be generalizable to adults living in Thailand. The findings of this study emphasize the importance of establishing specific hematologic reference values for specific populations. © 2018 John Wiley & Sons Ltd.

Complex reference values for endocrine and special chemistry biomarkers across pediatric, adult, and geriatric ages: establishment of robust pediatric and adult reference intervals on the basis of the Canadian Health Measures Survey.

PubMed

Adeli, Khosrow; Higgins, Victoria; Nieuwesteeg, Michelle; Raizman, Joshua E; Chen, Yunqi; Wong, Suzy L; Blais, David

2015-08-01

Defining laboratory biomarker reference values in a healthy population and understanding the fluctuations in biomarker concentrations throughout life and between sexes are critical to clinical interpretation of laboratory test results in different disease states. The Canadian Health Measures Survey (CHMS) has collected blood samples and health information from the Canadian household population. In collaboration with the Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER), the data have been analyzed to determine reference value distributions and reference intervals for several endocrine and special chemistry biomarkers in pediatric, adult, and geriatric age groups. CHMS collected data and blood samples from thousands of community participants aged 3 to 79 years. We used serum samples to measure 13 immunoassay-based special chemistry and endocrine markers. We assessed reference value distributions and, after excluding outliers, calculated age- and sex-specific reference intervals, along with corresponding 90% CIs, according to CLSI C28-A3 guidelines. We observed fluctuations in biomarker reference values across the pediatric, adult, and geriatric age range, with stratification required on the basis of age for all analytes. Additional sex partitions were required for apolipoprotein AI, homocysteine, ferritin, and high sensitivity C-reactive protein. The unique collaboration between CALIPER and CHMS has enabled, for the first time, a detailed examination of the changes in various immunochemical markers that occur in healthy individuals of different ages. The robust age- and sex-specific reference intervals established in this study provide insight into the complex biological changes that take place throughout development and aging and will contribute to improved clinical test interpretation. © 2015 American Association for Clinical Chemistry.

A generic biokinetic model for noble gases with application to radon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leggett, Richard Wayne; Marsh, James; Gregoratto, Demetrio

The International Commission for Radiological Protection (ICRP) currently uses a dose conversion coefficient to calculate effective dose per unit exposure to radon and its progeny. The coefficient is derived by dividing the detriment associated with unit exposure to radon, as estimated from epidemiological studies, by the detriment per unit effective dose, as estimated mainly from atomic bomb survivor data and animal studies. In a recent statement the ICRP indicated that future guidance on exposure to radon and its progeny will be developed in the same way as guidance for any other radionuclide. That is, intake of radon and progeny willmore » be limited on the basis of effective dose coefficients derived from biokinetic and dosimetric models. This paper proposes a biokinetic model for systemic (absorbed) radon for use in the calculation of dose coefficients for inhaled or ingested radon. The model is based largely on physical laws governing transfer of a non-reactive and soluble gas between materials. Model predictions are shown to be consistent with results of controlled studies of the fate of internally deposited radon in human subjects.« less

Proposed biokinetic model for phosphorus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leggett, Richard Wayne

2014-06-04

This paper reviews data related to the biokinetics of phosphorus in the human body and proposes a biokinetic model for systemic phosphorus for use in updated International Commission on Radiological Protection (ICRP) guidance on occupational intake of radionuclides. Compared with the ICRP s current occupational model for phosphorus (Publication 68, 1994) the proposed model provides a more realistic description of the paths of movement of phosphorus in the body and improved consistency with experimental, medical, and environmental data on the time-dependent distribution and retention of phosphorus following uptake to blood. For acute uptake of 32P to blood, the proposed modelmore » yields roughly a 50% decrease in dose estimates for bone surface and red marrow and a 6-fold increase in estimates for liver and kidney compared with the biokinetic model of Publication 68 (applying Publication 68 dosimetric models in both sets of calculations). For acute uptake of 33P to blood, the proposed model yields roughly a 50% increase in dose estimates for bone surface and red marrow and a 7-fold increase in estimates for liver and kidney compared with the model of Publication 68.« less

EVALUATION OF EYE LENS DOSE TO WORKERS IN THE STEAM GENERATOR AT THE KOREAN OPTIMIZED POWER REACTOR 1000.

PubMed

Maeng, Sung Jun; Kim, Jinhwan; Cho, Gyuseong

2018-03-15

ICRP (2011) revised the dose limit to the eye lens to 20 mSv/y based on a recent epidemiological study of radiation-induced cataracts. Maintenance of steam generators at nuclear power plants is one of the highest radiation-associated tasks within a non-uniform radiation field. This study aims to evaluate eye lens doses in the steam generators of the Korean OPR1000 design. The source term was characterized based on the CRUD-specific activity, and both the eye lens dose and organ dose were simulated using MCNP6 combined with an ICRP voxel phantom and a mesh phantom, respectively. The eye lens dose was determined to be 5.39E-02-9.43E-02 Sv/h, with a negligible effect by beta particles. As the effective dose was found to be 0.81-1.21 times the lens equivalent dose depending on the phantom angles, the former can be used to estimate the lens dose in the SG of the OPR1000 for radiation monitoring purposes.

Cosmic radiation in aviation: radiological protection of Air France aircraft crew.

PubMed

Desmaris, G

2016-06-01

Cosmic radiation in aviation has been a concern since the 1960s, and measurements have been taken for several decades by Air France. Results show that aircraft crew generally receive 3-4 mSv y(-1) for 750 boarding hours. Compliance with the trigger level of 6 mSv y(-1) is achieved by route selection. Work schedules can be developed for pregnant pilots to enable the dose to the fetus to be kept below 1 mSv. Crew members are informed of their exposition and the potential health impact. The upcoming International Commission on Radiological Protection (ICRP) report on cosmic radiation in aviation will provide an updated guidance. A graded approach proportionate with the time of exposure is recommended to implement the optimisation principle. The objective is to keep exposures of the most exposed aircraft members to reasonable levels. ICRP also recommends that information about cosmic radiation be disseminated, and that awareness about cosmic radiation be raised in order to favour informed decision-making by all concerned stakeholders. © The International Society for Prosthetics and Orthotics.

Adaptation of the ICRP publication 66 respiratory tract model to data on plutonium biokinetics for Mayak workers.

PubMed

Khokhryakov, V F; Suslova, K G; Vostrotin, V V; Romanov, S A; Eckerman, K F; Krahenbuhl, M P; Miller, S C

2005-02-01

The biokinetics of inhaled plutonium were analyzed using compartment models representing their behavior within the respiratory tract, the gastrointestinal tract, and in systemic tissues. The processes of aerosol deposition, particle transport, absorption, and formation of a fixed deposit in the respiratory tract were formulated in the framework of the Human Respiratory Tract Model described in ICRP Publication 66. The values of parameters governing absorption and formation of the fixed deposit were established by fitting the model to the observations in 530 autopsy cases. The influence of smoking on mechanical clearance of deposited plutonium activity was considered. The dependence of absorption on the aerosol transportability, as estimated by in vitro methods (dialysis), was demonstrated. The results of this study were compared to those obtained from an earlier model of plutonium behavior in the respiratory tract, which was based on the same set of autopsy data. That model did not address the early phases of respiratory clearance and hence underestimated the committed lung dose by about 25% for plutonium oxides. Little difference in lung dose was found for nitrate forms.

NOTE: Monte Carlo evaluation of kerma in an HDR brachytherapy bunker

NASA Astrophysics Data System (ADS)

Pérez-Calatayud, J.; Granero, D.; Ballester, F.; Casal, E.; Crispin, V.; Puchades, V.; León, A.; Verdú, G.

2004-12-01

In recent years, the use of high dose rate (HDR) after-loader machines has greatly increased due to the shift from traditional Cs-137/Ir-192 low dose rate (LDR) to HDR brachytherapy. The method used to calculate the required concrete and, where appropriate, lead shielding in the door is based on analytical methods provided by documents published by the ICRP, the IAEA and the NCRP. The purpose of this study is to perform a more realistic kerma evaluation at the entrance maze door of an HDR bunker using the Monte Carlo code GEANT4. The Monte Carlo results were validated experimentally. The spectrum at the maze entrance door, obtained with Monte Carlo, has an average energy of about 110 keV, maintaining a similar value along the length of the maze. The comparison of results from the aforementioned values with the Monte Carlo ones shows that results obtained using the albedo coefficient from the ICRP document more closely match those given by the Monte Carlo method, although the maximum value given by MC calculations is 30% greater.

Development of the Updated Environmental Protection Agency Manual of Protective Action Guides (PAGS) and Protective Actions for Nuclear Incidents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carter, L.M.

2008-07-01

As a student intern with the United States Environmental Protection Agency (EPA) Headquarters, the author was trained in the National Response Plan (NRP) and assisted in the editing of the new (unpublished) EPA Protective Action Guides (PAGs) [1] which has been revised in light of the perceived post 9/11 potential for 'Dirty Bomb' and 'Improvised Nuclear Device' attacks on civilian areas. Technical aspects and the public policy aspects of developing the new guides are discussed. Early Phase initial responses discussed include: Notification of state and/or local authorities, immediate evacuation/sheltering prior to release information or measurements, monitoring of releases and exposuremore » rate measurements, estimation of dose consequences, implementation of protective actions in other areas. The new PAG clarifies the use of 1992 PAGs [2] for incidents other than nuclear power plant accidents, lowers projected thyroid dose for potassium iodine (KI), provides drinking water guidance, includes guidance for long-term site restoration, and updates dosimetry from ICRP 26 to ICRP 60. (authors)« less

Ethical foundations of the radiological protection system.

PubMed

Cho, K W

2016-06-01

The International Commission on Radiological Protection (ICRP) has established Task Group 94 under Committee 4 to develop a report on the ethical foundations of the system of radiological protection. The aim of this report is to consolidate the basis of ICRP recommendations, to improve understanding of the system, and to provide a basis for communication on radiation risk and its perception. Through a series of workshops organised by the Commission in cooperation with the International Radiation Protection Association and its associate societies involving radiological protection professionals and specialists of ethics around the world, Task Group 94 has identified the key ethical and social values underpinning the system of radiological protection. The purpose of eliciting the ethical principles and values of the radiological protection system is not only to clarify the rationale for recommendations made by the Commission, but also to assist in discussions related to its practical implementation. A clear understanding of the ethical principles will help resolve dilemmas caused by potential conflicts in actions that might be considered, or decisions that must be made. © The International Society for Prosthetics and Orthotics.

Reference ranges of lymphocyte subsets balanced for age and gender from a population of healthy adults in Chongqing District of China.

PubMed

Zhang, Kejun; Wang, Feng; Zhang, Mingxu; Cao, Xinglu; Yang, Shaojun; Jia, Shuangrong; Wang, Lixin; Luo, Jie; Deng, Shaoli; Chen, Ming

2016-11-01

The enumeration of lymphocyte subsets plays an essential role in the monitoring of immunological disorders. Immunophenotyping values have been found to be influenced by race, age, gender, and environmental conditions. Therefore, it is important to establish reference ranges for healthy adults from the local population for clinical decision-making. The current study aimed to establish a normal reference range for peripheral blood lymphocyte subsets in healthy adults from the Chongqing District of China by using single-platform flow cytometry. Age- and gender-specific reference ranges were established in 268 healthy adult males and females between 21 and 60 years of age. The CD8+ cell counts decreased with age, CD4+ cell percentages and counts increased with age, and total T cell percentages were higher in the female population. Our results are similar to those reported from other parts of China but different from some results reported from other countries; this further stresses the need to establish local reference ranges by region. Our results will help in the management of patients with human immunodeficiency virus and other immunological disorders in Chongqing District. © 2015 International Clinical Cytometry Society. © 2015 International Clinical Cytometry Society.

Asthma and Respiratory Foundation NZ adult asthma guidelines: a quick reference guide.

PubMed

Beasley, Richard; Hancox, Robert J; Harwood, Matire; Perrin, Kyle; Poot, Betty; Pilcher, Janine; Reid, Jim; Talemaitoga, Api; Thayabaran, Darmiga

2016-11-18

The purpose of the Asthma and Respiratory Foundation NZ Adult Asthma Guidelines is to provide simple, practical and evidence-based recommendations for the diagnosis, assessment and management of asthma in adults (aged 16 and over) in a quick reference format. The intended users are health professionals responsible for delivering asthma care in the community and hospital Emergency Department settings, and those responsible for the training of such health professionals.

A kinematic model to estimate effective dose of radioactive substances in a human body

NASA Astrophysics Data System (ADS)

Sasaki, S.; Yamada, T.

2013-05-01

The great earthquake occurred in the north-east area in Japan in March 11, 2011. Facility system to control Fukushima Daiichi nuclear power station was completely destroyed by the following giant tsunami. From the damaged reactor containment vessels, an amount of radioactive substances had leaked and diffused in the vicinity of this station. Radiological internal exposure became a serious social issue both in Japan and all over the world. The present study provides an easily understandable, kinematic-based model to estimate the effective dose of radioactive substances in a human body by simplifying the complicated mechanism of metabolism. International Commission on Radiological Protection (ICRP) has developed a sophisticated model, which is well-known as a standard method to calculate the effective dose for radiological protection. However, owing to that ICRP method is fine, it is rather difficult for non-professional people of radiology to gasp the whole images of the movement and the influences of radioactive substances in a human body. Therefore, in the present paper we propose a newly-derived and easily-understandable model to estimate the effective dose. The present method is very similar with the traditional and conventional tank model in hydrology. Ingestion flux of radioactive substances corresponds to rain intensity and the storage of radioactive substances to the water storage in a basin in runoff analysis. The key of the present method is to estimate the energy radiated in the radioactive nuclear disintegration of an atom by using classical theory of β decay and special relativity for various kinds of radioactive atoms. The parameters used in this model are only physical half-time and biological half-time, and there are no operational parameters or coefficients to adjust our theoretical runoff to ICRP. Figure shows the time-varying effective dose with ingestion duration, and we can confirm the validity of our model. The time-varying effective dose with ingestion duration

Strontium-90 Biokinetics from Simulated Wound Intakes in Non-human Primates Compared with Combined Model Predictions from National Council on Radiation Protection and Measurements Report 156 and International Commission on Radiological Protection Publication 67.

PubMed

Allen, Mark B; Brey, Richard R; Gesell, Thomas; Derryberry, Dewayne; Poudel, Deepesh

2016-01-01

This study had a goal to evaluate the predictive capabilities of the National Council on Radiation Protection and Measurements (NCRP) wound model coupled to the International Commission on Radiological Protection (ICRP) systemic model for 90Sr-contaminated wounds using non-human primate data. Studies were conducted on 13 macaque (Macaca mulatta) monkeys, each receiving one-time intramuscular injections of 90Sr solution. Urine and feces samples were collected up to 28 d post-injection and analyzed for 90Sr activity. Integrated Modules for Bioassay Analysis (IMBA) software was configured with default NCRP and ICRP model transfer coefficients to calculate predicted 90Sr intake via the wound based on the radioactivity measured in bioassay samples. The default parameters of the combined models produced adequate fits of the bioassay data, but maximum likelihood predictions of intake were overestimated by a factor of 1.0 to 2.9 when bioassay data were used as predictors. Skeletal retention was also over-predicted, suggesting an underestimation of the excretion fraction. Bayesian statistics and Monte Carlo sampling were applied using IMBA to vary the default parameters, producing updated transfer coefficients for individual monkeys that improved model fit and predicted intake and skeletal retention. The geometric means of the optimized transfer rates for the 11 cases were computed, and these optimized sample population parameters were tested on two independent monkey cases and on the 11 monkeys from which the optimized parameters were derived. The optimized model parameters did not improve the model fit in most cases, and the predicted skeletal activity produced improvements in three of the 11 cases. The optimized parameters improved the predicted intake in all cases but still over-predicted the intake by an average of 50%. The results suggest that the modified transfer rates were not always an improvement over the default NCRP and ICRP model values.

A physiologically based pharmacokinetic model for lactational transfer of Na-131I

NASA Astrophysics Data System (ADS)

Turner, Anita Loretta

The excretion of radionuclides in human breast milk after administration of radiopharmaceuticals is a concern as a radiation risk to nursing infants. It is not uncommon to administer radiopharmaceuticals to lactating patients due to emergency nuclear medicine investigations such as thyroid complications, kidney failure, and pulmonary embolism. There is a need to quantify the amount of radioactivity translocated into breast milk in cases of ingestion by a breast-fed infant. A physiologically based pharmacokinetic model (PBPK) and a modified International Commission on Radiological Protection (ICRP) model have been developed to predict iodine concentrations in breast milk after ingestion of radioiodine by the mother. In the PBPK model, all compartments are interconnected by blood flow and represent real anatomic tissue regions in the body. All parameters involved are measurable values with physiological or physiochemical meaning such as tissue masses, blood flow rates, partition coefficients and cardiac output. However, some of the parameters such as the partition coefficients and metabolic constants are not available for iodine and had to be inferred from other information. The structure of the PBPK model for the mother consists of the following tissue compartments: gastrointestinal tract, blood, kidney, thyroid, milk, and other tissues. With the exception of the milk compartment, the model for the nursing infant is structured similarly to the mother. The ICRP model describing iodine metabolism in a standard 70-kg man was modified to represent iodine metabolism in a lactating woman and nursing infant. The parameters involved in this model are transfer rates and biological half-lives which are based on experimental observations. The results of the PBPK model and the modified ICRP model describing the lactational transfer of iodine were compared. When administering 1 mCi of Na131I to the lactating mother, the concentration reaches a maximum of 0.1 mCi/liter in 24 hours and decreases with an effective half-life of 1.2 day.

Predicted body weight relationships for protective ventilation - unisex proposals from pre-term through to adult.

PubMed

Martin, Dion C; Richards, Glenn N

2017-05-23

The lung-protective ventilation bundle has been shown to reduce mortality in adult acute respiratory distress syndrome (ARDS). This concept has expanded to other areas of acute adult ventilation and is recommended for pediatric ventilation. A component of lung-protective ventilation relies on a prediction of lean body weight from height. The predicted body weight (PBW) relationship employed in the ARDS Network trial is considered valid only for adults, with a dedicated formula required for each sex. No agreed PBW formula applies to smaller body sizes. This analysis investigated whether it might be practical to derive a unisex PBW formula spanning all body sizes, while retaining relevance to established adult protective ventilation practice. Historic population-based growth charts were adopted as a reference for lean body weight, from pre-term infant through to adult median weight. The traditional ARDSNet PBW formulae acted as the reference for prevailing protective ventilation practice. Error limits for derived PBW models were relative to these references. The ARDSNet PBW formulae typically predict weights heavier than the population median, therefore no single relationship could satisfy both references. Four alternate piecewise-linear lean body-weight predictive formulae were presented for consideration, each with different balance between the objectives. The 'PBWuf + MBW' model is proposed as an appropriate compromise between prevailing practice and simplification, while also better representing lean adult body-weight. This model applies the ARDSNet 'female' formula to both adult sexes, while providing a tight fit to median body weight at smaller statures down to pre-term. The 'PBWmf + MBW' model retains consistency with current practice over the adult range, while adding prediction for small statures.

Estimation of ultrasound reference values for the lower limb peripheral nerves in adults: A cross-sectional study.

PubMed

Bedewi, Mohamed Abdelmohsen; Abodonya, Ahmed; Kotb, Mamdouh; Kamal, Sanaa; Mahmoud, Gehan; Aldossari, Khaled; Alqabbani, Abdullah; Swify, Sherine

2018-03-01

The objective of this study is to estimate the reference values for the lower limb peripheral nerves in adults.The demographics and physical characteristics of 69 adult healthy volunteers were evaluated and recorded. The estimated reference values and their correlations with the age, weight, height, body mass index (BMI) were evaluated.The cross sectional area reference values were obtained at 5 predetermined sites for 3 important lower limb peripheral nerves. Our CSA values correlated significantly with age, weight, and BMI. The normal reference values for each nerve were as follows: Tibial nerve at the popliteal fossa 19 mm ± 6.9, tibial nerve at the level of the medial malleolus 12.7 mm ± 4.5, common peroneal nerve at the popliteal fossa 9.5 mm ± 4, common peroneal nerve fibular head 8.9 mm ± 3.2, sural nerve 3.5 mm ± 1.4.The reference values for the lower limb peripheral nerves were identified. These values could be used for future management of peripheral nerve disorders.

Changes in radiation dose with variations in human anatomy: moderately and severely obese adults.

PubMed

Clark, Landon D; Stabin, Michael G; Fernald, Michael J; Brill, Aaron B

2010-06-01

The phantoms used in standardized dose assessment are based on a median (i.e., 50th percentile) individual of a large population, for example, adult males or females or children of a particular age. Here we describe phantoms that model instead the influence of obesity on specific absorbed fractions (SAFs) and dose factors in adults. The literature was reviewed to evaluate how individual organ sizes change with variations in body weight in mildly and severely obese adult men and women. On the basis of the literature evaluation, changes were made to our deformable reference adult male and female total-body models. Monte Carlo simulations of radiation transport were performed. SAFs for photons were generated for mildly and severely obese adults, and comparisons were made to the reference (50th) percentile SAF values. SAFs studied between the obese phantoms and the 50th percentile reference phantoms were not significantly different from the reference 50th percentile individual, with the exception of intestines irradiating some abdominal organs, because of an increase in separation between folds caused by an increase in mesenteric adipose deposits. Some low-energy values for certain organ pairs were different, possibly due only to the statistical variability of the data at these low energies. The effect of obesity on dose calculations for internal emitters is minor and may be neglected in the routine use of standardized dose estimates.

Determination of Age-Dependent Reference Ranges for Coagulation Tests Performed Using Destiny Plus.

PubMed

Arslan, Fatma Demet; Serdar, Muhittin; Merve Ari, Elif; Onur Oztan, Mustafa; Hikmet Kozcu, Sureyya; Tarhan, Huseyin; Cakmak, Ozgur; Zeytinli, Merve; Yasar Ellidag, Hamit

2016-06-01

In order to apply the right treatment for hemostatic disorders in pediatric patients, laboratory data should be interpreted with age-appropriate reference ranges. The purpose of this study was to determining age-dependent reference range values for prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen tests, and D-dimer tests. A total of 320 volunteers were included in the study with the following ages: 1 month - 1 year (n = 52), 2 - 5 years (n = 50), 6 - 10 years (n = 48), 11 - 17 years (n = 38), and 18 - 65 years (n = 132). Each volunteer completed a survey to exclude hemostatic system disorder. Using a nonparametric method, the lower and upper limits, including 95% distribution and 90% confidence intervals, were calculated. No statistically significant differences were found between PT and aPTT values in the groups consisting of children. Thus, the reference ranges were separated into child and adult age groups. PT and aPTT values were significantly higher in the children than in the adults. Fibrinogen values in the 6 - 10 age group and the adult age group were significantly higher than in the other groups. D-dimer levels were significantly lower in those aged 2 - 17; thus, a separate reference range was established. These results support other findings related to developmental hemostasis, confirming that adult and pediatric age groups should be evaluated using different reference ranges.

Word learning in adults with second-language experience: effects of phonological and referent familiarity.

PubMed

Kaushanskaya, Margarita; Yoo, Jeewon; Van Hecke, Stephanie

2013-04-01

The goal of this research was to examine whether phonological familiarity exerts different effects on novel word learning for familiar versus unfamiliar referents and whether successful word learning is associated with increased second-language experience. Eighty-one adult native English speakers with various levels of Spanish knowledge learned phonologically familiar novel words (constructed using English sounds) or phonologically unfamiliar novel words (constructed using non-English and non-Spanish sounds) in association with either familiar or unfamiliar referents. Retention was tested via a forced-choice recognition task. A median-split procedure identified high-ability and low-ability word learners in each condition, and the two groups were compared on measures of second-language experience. Findings suggest that the ability to accurately match newly learned novel names to their appropriate referents is facilitated by phonological familiarity only for familiar referents but not for unfamiliar referents. Moreover, more extensive second-language learning experience characterized superior learners primarily in one word-learning condition: in which phonologically unfamiliar novel words were paired with familiar referents. Together, these findings indicate that phonological familiarity facilitates novel word learning only for familiar referents and that experience with learning a second language may have a specific impact on novel vocabulary learning in adults.

Word learning in adults with second language experience: Effects of phonological and referent familiarity

PubMed Central

Kaushanskaya, Margarita; Yoo, Jeewon; Van Hecke, Stephanie

2014-01-01

Purpose The goal of this research was to examine whether phonological familiarity exerts different effects on novel word learning for familiar vs. unfamiliar referents, and whether successful word-learning is associated with increased second-language experience. Method Eighty-one adult native English speakers with various levels of Spanish knowledge learned phonologically-familiar novel words (constructed using English sounds) or phonologically-unfamiliar novel words (constructed using non-English and non-Spanish sounds) in association with either familiar or unfamiliar referents. Retention was tested via a forced-choice recognition-task. A median-split procedure identified high-ability and low-ability word-learners in each condition, and the two groups were compared on measures of second-language experience. Results Findings suggest that the ability to accurately match newly-learned novel names to their appropriate referents is facilitated by phonological familiarity only for familiar referents but not for unfamiliar referents. Moreover, more extensive second-language learning experience characterized superior learners primarily in one word-learning condition: Where phonologically-unfamiliar novel words were paired with familiar referents. Conclusions Together, these findings indicate that phonological familiarity facilitates novel word learning only for familiar referents, and that experience with learning a second language may have a specific impact on novel vocabulary learning in adults. PMID:22992709

Assessing risk with increasingly stringent public health goals: the case of water lead and blood lead in children.

PubMed

Triantafyllidou, Simoni; Gallagher, Daniel; Edwards, Marc

2014-03-01

Previous predictions of children's blood lead levels (BLLs) through biokinetic models conclude that lead in tap water is not a primary health risk for a typical child under scenarios representative of chronic exposure, when applying a 10 μg/dL BLL of concern. Use of the US Environmental Protection Agency Integrated Exposure Uptake Biokinetic (IEUBK) model and of the International Commission on Radiological Protection (ICRP) biokinetic model to simulate children's exposure to water lead at home and at school was re-examined by expanding the scope of previous modeling efforts to consider new public health goals and improved methodology. Specifically, explicit consideration of the more sensitive population groups (e.g., young children and, particularly, formula-fed infants), the variability in BLLs amongst exposed individuals within those groups (e.g., more sensitive children at the upper tail of the BLL distribution), more conservative BLL reference values (e.g., 5 and 2 μg/dL versus 10 μg/dL) and concerns of acute exposure revealed situations where relatively low water lead levels were predicted to pose a human health concern.

Problems with detection of intakes of very insoluble plutonium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bihl, D.E.; Lynch, T.P.; Carbaugh, E.H.

1988-08-01

Several human cases involving inhalation of plutonium oxide at Hanford have shown clearance half-times from the lung that are much longer than those recommended for class Y material in Publication 30 of the International Commission on Radiological Protection (ICRP 1979). Because the material is much more tenaciously retained in the lung than ''normal'' class Y material, the Hanford Internal Dosimetry Program has been referring to it as ''super'' class Y. This material poses some major challenges with regard to the design and operation of bioassay monitoring programs. Because of the relative completeness of their data, 10 cases that show lungmore » retention half-times in excess of 5000 days are of particular interest. However, the bioassay data for these cases span the past 30 years and involve various sampling methods and detection limits in vogue at the time. Furthermore, the data were collected for the purpose of determining compliance with regulations in place at the time, rather than for research or modeling of clearance pathways and rates. So from a modeling perspective, the data have gaps, but are sufficiently complete to be convincing. 3 refs., 2 figs., 2 tabs.« less

Long-term follow-up of HAN-1, an acute plutonium oxide inhalation case

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carbaugh, E.H.; Bihl, D.E.; Sula, M.J.

1990-06-01

The International Commission on Radiation Protection (ICRP) has recommended that plutonium oxide be designated an inhalation class Y material, indicating that a 500-day clearance half-time from the lung is adequate for radiation protection purposes. Based on extensive data obtained from one particular inhalation case (referred to here as HAN-1), and supported by somewhat less detailed data in nine other cases, an argument has been put forth that substantially longer clearance half-times may not be uncommon for Pu oxide. This has led to the tentative identification of a super class Y'' form of Pu which has been factored into worker monitoringmore » programs at the US Department of Energy's Hanford Site. In addition, the United States Transuranium Registry autopsy work has indicted evidence to support the super class Y case. The particular case described in this paper was the key case which caused the Hanford internal dosimetry staff to seriously consider super class Y material. This paper includes data from long-term follow up monitoring as well as early data for calculating intakes for comparisons with secondary limits. 13 refs, 2 figs., 1 tab.« less

Radiation transport calculations for cosmic radiation.

PubMed

Endo, A; Sato, T

2012-01-01

The radiation environment inside and near spacecraft consists of various components of primary radiation in space and secondary radiation produced by the interaction of the primary radiation with the walls and equipment of the spacecraft. Radiation fields inside astronauts are different from those outside them, because of the body's self-shielding as well as the nuclear fragmentation reactions occurring in the human body. Several computer codes have been developed to simulate the physical processes of the coupled transport of protons, high-charge and high-energy nuclei, and the secondary radiation produced in atomic and nuclear collision processes in matter. These computer codes have been used in various space radiation protection applications: shielding design for spacecraft and planetary habitats, simulation of instrument and detector responses, analysis of absorbed doses and quality factors in organs and tissues, and study of biological effects. This paper focuses on the methods and computer codes used for radiation transport calculations on cosmic radiation, and their application to the analysis of radiation fields inside spacecraft, evaluation of organ doses in the human body, and calculation of dose conversion coefficients using the reference phantoms defined in ICRP Publication 110. Copyright © 2012. Published by Elsevier Ltd.

76 FR 53847 - New International Commission on Radiological Protection; Recommendations on the Annual Dose Limit...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-30

... Radiological Protection; Recommendations on the Annual Dose Limit to the Lens of the Eye AGENCY: Nuclear... Protection (ICRP) recommendations for the limitation of annual dose to the lens of the eye. This significant... might be lower than previously considered. For the lens of the eye, the threshold in absorbed dose for...

75 FR 59160 - Radiation Protection Regulations and Guidance; Public Meetings and Request for Comments

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-27

..., which are based on a more diverse world population? Issue No. 2: Occupational Dose Limits The... between the ICRP values and the EPA values stems primarily from the use of a U.S. population cancer... worldwide population. In discussion with stakeholders to date, the majority have been generally in favor of...

Glossary of Adult Learning in Europe. A.E. Monographs.

ERIC Educational Resources Information Center

Federighi, Paolo, Ed.

This document presents detailed "definitions" of more than 150 key terms covering the lexicon currently being used in the field of adult learning in 20 European countries. The document begins with an introduction that discusses the glossary's theoretical and historical references and includes 14 references and a 16-item bibliography. The…

Untreated ADHD in Adults: Are There Sex Differences in Symptoms, Comorbidity, and Impairment?

ERIC Educational Resources Information Center

Rasmussen, Kirsten; Levander, Sten

2009-01-01

Objective: To analyze sex differences among adult, never-treated patients referred for central stimulant treatment of ADHD. Method: Data for 600 consecutive patients from northern Norway referred for evaluation by an expert team during 7 years were analyzed. General background information, diagnostic and social history, and symptom profiles were…

Word Learning in Adults with Second-Language Experience: Effects of Phonological and Referent Familiarity

ERIC Educational Resources Information Center

Kaushanskaya, Margarita; Yoo, Jeewon; Van Hecke, Stephanie

2013-01-01

Purpose: The goal of this research was to examine whether phonological familiarity exerts different effects on novel word learning for familiar versus unfamiliar referents and whether successful word learning is associated with increased second-language experience. Method: Eighty-one adult native English speakers with various levels of Spanish…

The Nature of Adult and Continuing Education in Nigeria with Special Reference to Sokoto.

ERIC Educational Resources Information Center

Mattimore-Knudson, Russell S.

There are three major kinds of adult education in Nigeria today--traditional adult education, formal adult education, and Islamic adult education. Because it is the form of adult education most promoted by the government, formal adult education is the most dominant approach found in Nigeria. A look at Nigeria's national policy on education…

Transfer of innovation on allergic rhinitis and asthma multimorbidity in the elderly (MACVIA-ARIA) - EIP on AHA Twinning Reference Site (GARD research demonstration project).

PubMed

Bousquet, J; Agache, I; Aliberti, M R; Angles, R; Annesi-Maesano, I; Anto, J M; Arnavielhe, S; Asayag, E; Bacci, E; Bedbrook, A; Bachert, C; Baroni, I; Barreto, B A; Bedolla-Barajas, M; Bergmann, K C; Bertorello, L; Bewick, M; Bieber, T; Birov, S; Bindslev-Jensen, C; Blua, A; Bochenska Marciniak, M; Bogus-Buczynska, I; Bosnic-Anticevich, S; Bosse, I; Bourret, R; Bucca, C; Buonaiuto, R; Burguete Cabanas, M T; Caillaud, D; Caimmi, D P; Caiazza, D; Camargos, P; Canfora, G; Cardona, V; Carriazo, A M; Cartier, C; Castellano, G; Chavannes, N H; Cecci, L; Ciaravolo, M M; Cingi, C; Ciceran, A; Colas, L; Colgan, E; Coll, J; Conforti, D; Correia de Sousa, J; Cortés-Grimaldo, R M; Corti, F; Costa, E; Courbis, A L; Cousein, E; Cruz, A A; Custovic, A; Cvetkovski, B; Dario, C; da Silva, J; Dauvilliers, Y; De Blay, F; Dedeu, T; De Feo, G; De Martino, B; Demoly, P; De Vries, G; Di Capua Ercolano, S; Di Carluccio, N; Doulapsi, M; Dray, G; Dubakiene, R; Eller, E; Emuzyte, R; Espinoza-Contreras, J G; Estrada-Cardona, A; Farrell, J; Farsi, A; Ferrero, J; Fokkens, W J; Fonseca, J; Fontaine, J F; Forti, S; Gálvez-Romero, J L; García-Cobas, C I; Garcia Cruz, M H; Gemicioğlu, B; Gerth van Wijk, R; Guidacci, M; Gómez-Vera, J; Guldemond, N A; Gutter, Z; Haahtela, T; Hajjam, J; Hellings, P W; Hernández-Velázquez, L; Illario, M; Ivancevich, J C; Jares, E; Joos, G; Just, J; Kalayci, O; Kalyoncu, A F; Karjalainen, J; Keil, T; Khaltaev, N; Klimek, L; Kritikos, V; Kull, I; Kuna, P; Kvedariene, V; Kolek, V; Krzych-Fałta, E; Kupczyk, M; Lacwik, P; La Grutta, S; Larenas-Linnemann, D; Laune, D; Lauri, D; Lavrut, J; Lessa, M; Levato, G; Lewis, L; Lieten, I; Lipiec, A; Louis, R; Luna-Pech, J A; Magnan, A; Malva, J; Maspero, J F; Matta-Campos, J J; Mayora, O; Medina-Ávalos, M A; Melén, E; Menditto, E; Millot-Keurinck, J; Moda, G; Morais-Almeida, M; Mösges, R; Mota-Pinto, A; Mullol, J; Muraro, A; Murray, R; Noguès, M; Nalin, M; Napoli, L; Neffen, H; O'Hehir, R E; Onorato, G L; Palkonen, S; Papadopoulos, N G; Passalacqua, G; Pépin, J L; Pereira, A M; Persico, M; Pfaar, O; Pozzi, A C; Prokopakis, E; Pugin, B; Raciborski, F; Rimmer, J; Rizzo, J A; Robalo-Cordeiro, C; Rodríguez-González, M; Rolla, G; Roller-Wirnsberger, R E; Romano, A; Romano, M; Romano, M R; Salimäki, J; Samolinski, B; Serpa, F S; Shamai, S; Sierra, M; Sova, M; Sorlini, M; Stellato, C; Stelmach, R; Strandberg, T; Stroetmann, V; Stukas, R; Szylling, A; Tan, R; Tibaldi, V; Todo-Bom, A; Toppila-Salmi, S; Tomazic, P; Trama, U; Triggiani, M; Valero, A; Valovirta, E; Valiulis, A; van Eerd, M; Vasankari, T; Vatrella, A; Ventura, M T; Verissimo, M T; Viart, F; Williams, S; Wagenmann, M; Wanscher, C; Westman, M; Wickman, M; Young, I; Yorgancioglu, A; Zernotti, E; Zuberbier, T; Zurkuhlen, A; De Oliviera, B; Senn, A

2018-01-01

The overarching goals of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) are to enable European citizens to lead healthy, active and independent lives whilst ageing. The EIP on AHA includes 74 Reference Sites. The aim of this study was to transfer innovation from an app developed by the MACVIA-France EIP on AHA reference site (Allergy Diary) to other reference sites. The phenotypic characteristics of rhinitis and asthma multimorbidity in adults and the elderly will be compared using validated information and communication technology (ICT) tools (i.e. the Allergy Diary and CARAT: Control of Allergic Rhinitis and Asthma Test) in 22 Reference Sites or regions across Europe. This will improve the understanding, assessment of burden, diagnosis and management of rhinitis in the elderly by comparison with an adult population. Specific objectives will be: (i) to assess the percentage of adults and elderly who are able to use the Allergy Diary, (ii) to study the phenotypic characteristics and treatment over a 1-year period of rhinitis and asthma multimorbidity at baseline (cross-sectional study) and (iii) to follow-up using visual analogue scale (VAS). This part of the study may provide some insight into the differences between the elderly and adults in terms of response to treatment and practice. Finally (iv) work productivity will be examined in adults. © 2017 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.

Evaluation of Method-Specific Extraction Variability for the Measurement of Fatty Acids in a Candidate Infant/Adult Nutritional Formula Reference Material.

PubMed

Place, Benjamin J

2017-05-01

To address community needs, the National Institute of Standards and Technology has developed a candidate Standard Reference Material (SRM) for infant/adult nutritional formula based on milk and whey protein concentrates with isolated soy protein called SRM 1869 Infant/Adult Nutritional Formula. One major component of this candidate SRM is the fatty acid content. In this study, multiple extraction techniques were evaluated to quantify the fatty acids in this new material. Extraction methods that were based on lipid extraction followed by transesterification resulted in lower mass fraction values for all fatty acids than the values measured by methods utilizing in situ transesterification followed by fatty acid methyl ester extraction (ISTE). An ISTE method, based on the identified optimal parameters, was used to determine the fatty acid content of the new infant/adult nutritional formula reference material.

Organ doses can be estimated from the computed tomography (CT) dose index for cone-beam CT on radiotherapy equipment.

PubMed

Martin, Colin J; Abuhaimed, Abdullah; Sankaralingam, Marimuthu; Metwaly, Mohamed; Gentle, David J

2016-06-01

Cone beam computed tomography (CBCT) systems are fitted to radiotherapy linear accelerators and used for patient positioning prior to treatment by image guided radiotherapy (IGRT). Radiotherapists' and radiographers' knowledge of doses to organs from CBCT imaging is limited. The weighted CT dose index for a reference beam of width 20 mm (CTDIw,ref) is displayed on Varian CBCT imaging equipment known as an On-Board Imager (OBI) linked to the Truebeam linear accelerator. This has the potential to provide an indication of organ doses. This knowledge would be helpful for guidance of radiotherapy clinicians preparing treatments. Monte Carlo simulations of imaging protocols for head, thorax and pelvic scans have been performed using EGSnrc/BEAMnrc, EGSnrc/DOSXYZnrc, and ICRP reference computational male and female phantoms to derive the mean absorbed doses to organs and tissues, which have been compared with values for the CTDIw,ref displayed on the CBCT scanner console. Substantial variations in dose were observed between male and female phantoms. Nevertheless, the CTDIw,ref gave doses within  ±21% for the stomach and liver in thorax scans and 2  ×  CTDIw,ref can be used as a measure of doses to breast, lung and oesophagus. The CTDIw,ref could provide indications of doses to the brain for head scans, and the colon for pelvic scans. It is proposed that knowledge of the link between CTDIw for CBCT should be promoted and included in the training of radiotherapy staff.

A comparison of simple and realistic eye models for calculation of fluence to dose conversion coefficients in a broad parallel beam incident of protons

NASA Astrophysics Data System (ADS)

Sakhaee, Mahmoud; Vejdani-Noghreiyan, Alireza; Ebrahimi-Khankook, Atiyeh

2015-01-01

Radiation induced cataract has been demonstrated among people who are exposed to ionizing radiation. To evaluate the deterministic effects of ionizing radiation on the eye lens, several papers dealing with the eye lens dose have been published. ICRP Publication 103 states that the lens of the eye may be more radiosensitive than previously considered. Detailed investigation of the response of the lens showed that there are strong differences in sensitivity to ionizing radiation exposure with respect to cataract induction among the tissues of the lens of the eye. This motivated several groups to look deeper into issue of the dose to a sensitive cell population within the lens, especially for radiations with low energy penetrability that have steep dose gradients inside the lens. Two sophisticated mathematical models of the eye including the inner structure have been designed for the accurate dose estimation in recent years. This study focuses on the calculations of the absorbed doses of different parts of the eye using the stylized models located in UF-ORNL phantom and comparison with the data calculated with the reference computational phantom in a broad parallel beam incident of protons with energies between 20 MeV and 10 GeV. The obtained results indicate that the total lens absorbed doses of reference phantom has good compliance with those of the more sensitive regions of stylized models. However, total eye absorbed dose of these models greatly differ with each other for lower energies.

Diagnostic reference levels in low- and middle-income countries: early "ALARAm" bells?

PubMed

Meyer, Steven; Groenewald, Willem A; Pitcher, Richard D

2017-04-01

Background In 1996 the International Commission on Radiological Protection (ICRP) introduced diagnostic reference levels (DRLs) as a quality assurance tool for radiation dose optimization. While many countries have published DRLs, available data are largely from high-income countries. There is arguably a greater need for DRLs in low- and middle-income-countries (LMICs), where imaging equipment may be older and trained imaging technicians are scarce. To date, there has been no critical analysis of the published work on DRLs in LMICs. Such work is important to evaluate data deficiencies and stimulate future quality assurance initiatives. Purpose To review the published work on DRLs in LMICs and to critically analyze the comprehensiveness of available data. Material and Methods Medline, Scopus, and Web of Science database searches were conducted for English-language articles published between 1996 and 2015 documenting DRLs for diagnostic imaging in LMICs. Retrieved articles were analyzed and classified by geographical region, country of origin, contributing author, year of publication, imaging modality, body part, and patient age. Results Fifty-three articles reported DRLs for 28 of 135 LMICs (21%), reflecting data from 26/104 (25%) middle-income countries and 2/31 (6%) low-income countries. General radiography (n = 26, 49%) and computerized tomography (n = 17, 32%) data were most commonly reported. Pediatric DRLs (n = 14, 26%) constituted approximately one-quarter of published work. Conclusion Published DRL data are deficient in the majority of LMICs, with the paucity most striking in low-income countries. DRL initiatives are required in LMICs to enhance dose optimization.

Computational hybrid anthropometric paediatric phantom library for internal radiation dosimetry

NASA Astrophysics Data System (ADS)

Xie, Tianwu; Kuster, Niels; Zaidi, Habib

2017-04-01

Hybrid computational phantoms combine voxel-based and simplified equation-based modelling approaches to provide unique advantages and more realism for the construction of anthropomorphic models. In this work, a methodology and C++ code are developed to generate hybrid computational phantoms covering statistical distributions of body morphometry in the paediatric population. The paediatric phantoms of the Virtual Population Series (IT’IS Foundation, Switzerland) were modified to match target anthropometric parameters, including body mass, body length, standing height and sitting height/stature ratio, determined from reference databases of the National Centre for Health Statistics and the National Health and Nutrition Examination Survey. The phantoms were selected as representative anchor phantoms for the newborn, 1, 2, 5, 10 and 15 years-old children, and were subsequently remodelled to create 1100 female and male phantoms with 10th, 25th, 50th, 75th and 90th body morphometries. Evaluation was performed qualitatively using 3D visualization and quantitatively by analysing internal organ masses. Overall, the newly generated phantoms appear very reasonable and representative of the main characteristics of the paediatric population at various ages and for different genders, body sizes and sitting stature ratios. The mass of internal organs increases with height and body mass. The comparison of organ masses of the heart, kidney, liver, lung and spleen with published autopsy and ICRP reference data for children demonstrated that they follow the same trend when correlated with age. The constructed hybrid computational phantom library opens up the prospect of comprehensive radiation dosimetry calculations and risk assessment for the paediatric population of different age groups and diverse anthropometric parameters.

Identification of Dynapenia in Older Adults Through the Use of Grip Strength T-Scores

PubMed Central

Bohannon, Richard W; Magasi, Susan

2014-01-01

Objective To generate reference values and t-scores (1.0 to 2.5 standard deviations below average) for grip strength for healthy young adults and to examine the utility of t-scores from this group for the identification of dynapenia in older adults. Design Secondary analysis of cross-sectional grip strength data from the NIH Toolbox norming sample. Setting Population-based general community sample. Participants Community dwelling adults, between the ages 20 and 40 years (n=558); and 60 to 85 years (n=390) Main Outcomes Measures Grip strength measured with a Jamar plus dynamometer. Results Maximum grip strengths were consistent over the 20–40 year age span. For men they were 108.0 lbs (S.D. 22.6). For women, they were 65.8 lbs (S.D. 14.6) Comparison of older participant grip strengths to those of the younger reference group revealed (depending on age strata) that 46.2–87.1% of older men and 50.0–82.4% of older women could be designated as dynapenic on the basis of t-scores. Conclusion The use of reference value t-scores from younger adults is a promising method for determining dynapenia in older adults. PMID:24729356

Identification of dynapenia in older adults through the use of grip strength t-scores.

PubMed

Bohannon, Richard W; Magasi, Susan

2015-01-01

The aim of this study was to generate reference values and t-scores (1.0-2.5 standard deviations below average) for grip strength for healthy young adults and to examine the utility of t-scores from this group for the identification of dynapenia in older adults. Our investigation was a population-based, general community secondary analysis of cross-sectional grip strength data utilizing the NIH Toolbox Assessment norming sample. Participants consisted of community-dwelling adults, with age ranges of 20-40 years (n = 558) and 60-85 years (n = 390). The main outcome measure was grip strength using a Jamar plus dynamometer. Maximum grip strengths were consistent over the 20-40-year age group [men 108.0 (SD 22.6) pounds, women 65.8 (SD 14.6) pounds]. Comparison of older group grip strengths to those of the younger reference group revealed (depending on age strata) that 46.2-87.1% of older men and 50.0-82.4% of older women could be designated as dynapenic on the basis of t-scores. The use of reference value t-scores from younger adults is a promising method for determining dynapenia in older adults. © 2014 Wiley Periodicals, Inc.

Applicability of the Old European Respiratory Society/European Community for Steel and Coal reference equations for spirometry interpretation in Tunisian adult population.

PubMed

El Attar, Mohamed Nour; Hadj Mabrouk, Khaoula; Ben Abdelaziz, Ahmed; Abdelghani, Ahmed; Bousarssar, Mohamed; Limam, Khélifa; Maatoug, Chiraz; Bouslah, Hmida; Charrada, Ameur; Rouatbi, Sonia; Ben Saad, Helmi

2014-01-01

Tunisian pulmonary functional laboratories accept the default settings for reference equations (European Respiratory Society/European Community for Steel and Coal (ERS/ECSC1983) offered by the manufacturer even though adult Tunisian reference equations (Tunisian1995) are available. To compare the spirometric profile of Tunisian subjects, according to the two reference equations. Spirometric data were recorded from 1192 consecutive spirometry procedures in adults aged 18-60 years. Reference values and lower limits of normality (LLN) were calculated using the two reference equations. Applied definitions: large airway obstructive ventilatory defect (LAOVD): ratio between the 1st second expiratory volume and forced vital capacity (FEV1/FVC) < LLN. Small AOVD (SAOVD): FEV1/FVC > LLN and FVC > LLN and maximal midexpiratory flow < LLN. Tendency through a restrictive ventilatory defect (TRVD): FEV1 and FVC < LLN. The spirometric profile, according the two reference equations, was determined. Using Tunisian1995 reference equations, 34%, 7%, 37% and 19% of spirometry records were interpreted as normal, and as having, LAOVD, SAOVD and TRVD, respectively. Using ERS/ECSC1983 reference equations, 85%, 3%, 9% and 2% of spirometry records were interpreted as normal, and as having, LAOVD, SAOVD and TRVD, respectively. Using the ERS/ECSC1983 reference equations, misclassification was worse for LAOVD, for SAOVD and for TRVD, respectively, 68%, 94% and 89%. Our results showed that the use of the old Caucasian reference equations resulted in misinterpretation of spirometry data in a significant proportion of subjects. This could result in inappropriate diagnosis and/or management.

Determination of Age-Dependent Reference Ranges for Coagulation Tests Performed Using Destiny Plus

PubMed Central

Arslan, Fatma Demet; Serdar, Muhittin; Merve Ari, Elif; Onur Oztan, Mustafa; Hikmet Kozcu, Sureyya; Tarhan, Huseyin; Cakmak, Ozgur; Zeytinli, Merve; Yasar Ellidag, Hamit

2016-01-01

Background In order to apply the right treatment for hemostatic disorders in pediatric patients, laboratory data should be interpreted with age-appropriate reference ranges. Objectives The purpose of this study was to determining age-dependent reference range values for prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen tests, and D-dimer tests. Materials and Methods A total of 320 volunteers were included in the study with the following ages: 1 month - 1 year (n = 52), 2 - 5 years (n = 50), 6 - 10 years (n = 48), 11 - 17 years (n = 38), and 18 - 65 years (n = 132). Each volunteer completed a survey to exclude hemostatic system disorder. Using a nonparametric method, the lower and upper limits, including 95% distribution and 90% confidence intervals, were calculated. Results No statistically significant differences were found between PT and aPTT values in the groups consisting of children. Thus, the reference ranges were separated into child and adult age groups. PT and aPTT values were significantly higher in the children than in the adults. Fibrinogen values in the 6 - 10 age group and the adult age group were significantly higher than in the other groups. D-dimer levels were significantly lower in those aged 2 - 17; thus, a separate reference range was established. Conclusions These results support other findings related to developmental hemostasis, confirming that adult and pediatric age groups should be evaluated using different reference ranges. PMID:27617078

Repeatability, variability and reference values of pulsed wave Doppler echocardiographic measurements in healthy Saanen goats

PubMed Central

2012-01-01

Background Pulsed wave (PW) Doppler echocardiography has become a routine non invasive cardiac diagnostic tool in most species. However, evaluation of intracardiac blood flow requires reference values, which are poorly documented in goats. The aim of this study was to test the repeatability, the variability, and to establish the reference values of PW measurements in healthy adult Saanen goats. Using a standardised PW Doppler echocardiographic protocol, 10 healthy adult unsedated female Saanen goats were investigated three times at one day intervals by the same observer. Mitral, tricuspid, aortic and pulmonary flows were measured from a right parasternal view, and mitral and aortic flows were also measured from a left parasternal view. The difference between left and right side measurements and the intra-observer inter-day repeatability were tested and then the reference values of PW Doppler echocardiographic parameters in healthy adult female Saanen goats were established. Results As documented in other species, all caprine PW Doppler parameters demonstrated a poor inter-day repeatability and a moderate variability. Tricuspid and pulmonary flows were best evaluated on the right side whereas mitral and aortic flows were best obtained on the left side, and reference values are reported for healthy adult Saanen goats. Conclusions PW Doppler echocardiography allows the measurement of intracardiac blood flow indices in goats. The reference values establishment will help interpreting these indices of cardiac function in clinical cardiac cases and developing animal models for human cardiology research. PMID:23067875

Dosimetry in Diagnostic Radiology: A Guide for Meeting JCAHO and ACR requirements and ICRP Recommendations

DTIC Science & Technology

1998-01-01

C-Arms and Digital Fluorscopy ....... ............................. 6 Image Intensifier III) Input Exposure Rates and Exposures...Setup for ESE Measurements in Conventional Radiography .................. 3 Figure 2: Setup tor IP ;R M easurem ents...exposure from dental procedures. An area of dental radiography which has not been well addressed is the dose received during panoramic or panalipse

Operational health physics training

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1992-06-01

The initial four sections treat basic information concerning atomic structure and other useful physical quantities, natural radioactivity, the properties of {alpha}, {beta}, {gamma}, x rays and neutrons, and the concepts and units of radiation dosimetry (including SI units). Section 5 deals with biological effects and the risks associated with radiation exposure. Background radiation and man-made sources are discussed next. The basic recommendations of the ICRP concerning dose limitations: justification, optimization (ALARA concepts and applications) and dose limits are covered in Section seven. Section eight is an expanded version of shielding, and the internal dosimetry discussion has been extensively revised tomore » reflect the concepts contained in the MIRD methodology and ICRP 30. The remaining sections discuss the operational health physics approach to monitoring radiation. Individual sections include radiation detection principles, instrument operation and counting statistics, health physics instruments and personnel monitoring devices. The last five sections deal with the nature of, operation principles of, health physics aspects of, and monitoring approaches to air sampling, reactors, nuclear safety, gloveboxes and hot cells, accelerators and x ray sources. Decontamination, waste disposal and transportation of radionuclides are added topics. Several appendices containing constants, symbols, selected mathematical topics, and the Chart of the Nuclides, and an index have been included.« less

Human biodistribution and radiation dosimetry of 82Rb.

PubMed

Senthamizhchelvan, Srinivasan; Bravo, Paco E; Esaias, Caroline; Lodge, Martin A; Merrill, Jennifer; Hobbs, Robert F; Sgouros, George; Bengel, Frank M

2010-10-01

Prior estimates of radiation-absorbed doses from (82)Rb, a frequently used PET perfusion tracer, yielded discrepant results. We reevaluated (82)Rb dosimetry using human in vivo biokinetic measurements. Ten healthy volunteers underwent dynamic PET/CT (6 contiguous table positions, each with separate (82)Rb infusion). Source organ volumes of interest were delineated on the CT images and transferred to the PET images to obtain time-integrated activity coefficients. Radiation doses were estimated using OLINDA/EXM 1.0. The highest mean absorbed organ doses (μGy/MBq) were observed for the kidneys (5.81), heart wall (3.86), and lungs (2.96). Mean effective doses were 1.11 ± 0.22 and 1.26 ± 0.20 μSv/MBq using the tissue-weighting factors of the International Commission on Radiological Protection (ICRP), publications 60 and 103, respectively. Our current (82)Rb dosimetry suggests reasonably low radiation exposure. On the basis of this study, a clinical (82)Rb injection of 2 × 1,480 MBq (80 mCi) would result in a mean effective dose of 3.7 mSv using the weighting factors of the ICRP 103-only slightly above the average annual natural background exposure in the United States (3.1 mSv).

Software Development for Estimating the Conversion Factor (K-Factor) at Suitable Scan Areas, Relating the Dose Length Product to the Effective Dose.

PubMed

Kobayashi, Masanao; Asada, Yasuki; Matsubara, Kosuke; Suzuki, Syouichi; Koshida, Kichiro; Matsunaga, Yuta; Kawaguchi, Ai; Haba, Tomonobu; Toyama, Hiroshi; Kato, Ryouichi

2017-05-01

We developed a k-factor-creator software (kFC) that provides the k-factor for CT examination in an arbitrary scan area. It provides the k-factor from the effective dose and dose-length product by Imaging Performance Assessment of CT scanners and CT-EXPO. To assess the reliability, we compared the kFC-evaluated k-factors with those of the International Commission on Radiological Protection (ICRP) publication 102. To confirm the utility, the effective dose determined by coronary computed tomographic angiography (CCTA) was evaluated by a phantom study and k-factor studies. In the CCTA, the effective doses were 5.28 mSv in the phantom study, 2.57 mSv (51%) in the k-factor of ICRP, and 5.26 mSv (1%) in the k-factor of the kFC. Effective doses can be determined from the kFC-evaluated k-factors in suitable scan areas. Therefore, we speculate that the flexible k-factor is useful in clinical practice, because CT examinations are performed in various scan regions. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Radiation protection issues on preparedness and response for a severe nuclear accident: experiences of the Fukushima accident.

PubMed

Homma, T; Takahara, S; Kimura, M; Kinase, S

2015-06-01

Radiation protection issues on preparedness and response for a severe nuclear accident are discussed in this paper based on the experiences following the accident at Fukushima Daiichi nuclear power plant. The criteria for use in nuclear emergencies in the Japanese emergency preparedness guide were based on the recommendations of International Commission of Radiological Protection (ICRP) Publications 60 and 63. Although the decision-making process for implementing protective actions relied heavily on computer-based predictive models prior to the accident, urgent protective actions, such as evacuation and sheltering, were implemented effectively based on the plant conditions. As there were no recommendations and criteria for long-term protective actions in the emergency preparedness guide, the recommendations of ICRP Publications 103, 109, and 111 were taken into consideration in determining the temporary relocation of inhabitants of heavily contaminated areas. These recommendations were very useful in deciding the emergency protective actions to take in the early stages of the Fukushima accident. However, some suggestions have been made for improving emergency preparedness and response in the early stages of a severe nuclear accident. © The Chartered Institution of Building Services Engineers 2014.

Recent international regulations: low dose-low rate radiation protection and the demise of reason.

PubMed

Okkalides, Demetrios

2008-01-01

The radiation protection measures suggested by the International Committee for Radiation Protection (ICRP), national regulating bodies and experts, have been becoming ever more strict despite the decrease of any information supporting the existence of the Linear no Threshold model (LNT) and of any adverse effects of Low Dose Low Rate (LDLR) irradiation. This tendency arises from the disproportionate response of human society to hazards that are currently in fashion and is unreasonable. The 1 mSv/year dose limit for the public suggested by the ICRP corresponds to a 1/18,181 detriment-adjusted cancer risk and is much lower than other hazards that are faced by modern societies such as e.g. driving and smoking which carry corresponding rate risks of 1/2,100 and 1/2,000. Even worldwide deadly work accidents rate is higher at 1/ 8,065. Such excessive safety measures against minimal risks from man made radiation sources divert resources from very real and much greater hazards. In addition they undermine research and development of radiation technology and tend to subjugate science and the quest for understanding nature to phobic practices.

The Effect of Ivermectin in Seven Strains of Aedes aegypti (Diptera: Culicidae) Including a Genetically Diverse Laboratory Strain and Three Permethrin Resistant Strains

PubMed Central

Deus, K. M.; Saavedra-rodriguez, K.; Butters, M. P.; Black, W. C.; Foy, B. D.

2014-01-01

Seven different strains of Aedes aegypti (L.), including a genetically diverse laboratory strain, three laboratory-selected permethrin-resistant strains, a standard reference strain, and two recently colonized strains were fed on human blood containing various concentrations of ivermectin. Ivermectin reduced adult survival, fecundity, and hatch rate of eggs laid by ivermectin-treated adults in all seven strains. The LC50 of ivermectin for adults and the concentration that prevented 50% of eggs from hatching was calculated for all strains. Considerable variation in adult survival after an ivermectin-bloodmeal occurred among strains, and all three permethrin-resistant strains were significantly less susceptible to ivermectin than the standard reference strain. The hatch rate after an ivermectin bloodmeal was less variable among strains, and only one of the permethrin-resistant strains differed significantly from the standard reference strain. Our studies suggest that ivermectin induces adult mortality and decreases the hatch rate of eggs through different mechanisms. A correlation analysis of log-transformed LC50 among strains suggests that permethrin and ivermectin cross-resistance may occur. PMID:22493855

Adults in the "New" Competence Regime--Acquiring "The Sense of the Game"

ERIC Educational Resources Information Center

Tønseth, Christin

2015-01-01

How can political intentions concerning adult learning be realized when adults seem to have intentions and outcomes that go in many directions? This paper highlights some tensions and discrepancies between adult education policy goals, referred to as promoters for lifelong learning, and adults' outcomes from participation in learning. While some…

Clueless: Adult Mysteries with Young Adult Appeal 2002.

ERIC Educational Resources Information Center

Charles, John; Morrison, Joanna

2002-01-01

This annotated bibliography includes adult mysteries that appeal to teen readers under the categories of Sherlock Holmes; reference sources; private investigators; amateur sleuths; historical sleuths; suspense and thrillers; police procedurals; mystery blends; and anthologies. (LRW)

Conversational Grounding in Younger and Older Adults: The Effect of Partner Visibility and Referent Abstractness in Task-Oriented Dialogue

ERIC Educational Resources Information Center

Lysander, Katya; Horton, William S.

2012-01-01

Many communicative situations present interlocutors with the opportunity to use multiple modalities to establish shared perspectives on conversational referents, a process known as grounding. In the current study, we use a card-matching task to examine how conversational grounding in younger and older adults is influenced both by direct visual…

La Verneda-Sant Martí Adult School: A Reference for Neighborhood Popular Education

ERIC Educational Resources Information Center

Aubert, Adrianna; Villarejo, Bea; Cabré, Joan; Santos, Tatiana

2016-01-01

Background/Context: The Adult School of La Verneda Sant Martí, located in Barcelona, Spain, is a reference at the international level because of its trajectory and its contributions to the transformative movement in democratic education. The school was created in 1978 to address the demands of the working-class residents of the La Verneda…

Illinois Community College Board. Adult Education and Family Literacy. Provider Manual. Fiscal Year 2007

ERIC Educational Resources Information Center

Illinois Community College Board, 2007

2007-01-01

The Illinois Community College Board has developed this Provider Manual as an easy reference to: (1) existing laws and regulations, both State and Federal; (2) best practices in the field of Adult Education; and to (3) act as a desk reference for both new and existing program administrators. The Manual describes: (1) the purpose of the Federal…

Repositioning Ideology Critique in a Critical Theory of Adult Learning.

ERIC Educational Resources Information Center

Brookfield, Stephen

2001-01-01

Reexamines critical theory as a response to Marxism and repositions ideology critique as a crucial adult learning process. Argues that a critical theory of adult learning should focus on how adults learn to recognize and challenge ideological domination and manipulation. (Contains 31 references.) (SK)

Individualized adjustments to reference phantom internal organ dosimetry—scaling factors given knowledge of patient internal anatomy

NASA Astrophysics Data System (ADS)

Wayson, Michael B.; Bolch, Wesley E.

2018-04-01

Various computational tools are currently available that facilitate patient organ dosimetry in diagnostic nuclear medicine, yet they are typically restricted to reporting organ doses to ICRP-defined reference phantoms. The present study, while remaining computational phantom based, provides straightforward tools to adjust reference phantom organ dose for both internal photon and electron sources. A wide variety of monoenergetic specific absorbed fractions were computed using radiation transport simulations for tissue spheres of varying size and separation distance. Scaling methods were then constructed for both photon and electron self-dose and cross-dose, with data validation provided from patient-specific voxel phantom simulations, as well as via comparison to the scaling methodology given in MIRD Pamphlet No. 11. Photon and electron self-dose was found to be dependent on both radiation energy and sphere size. Photon cross-dose was found to be mostly independent of sphere size. Electron cross-dose was found to be dependent on sphere size when the spheres were in close proximity, owing to differences in electron range. The validation studies showed that this dataset was more effective than the MIRD 11 method at predicting patient-specific photon doses for at both high and low energies, but gave similar results at photon energies between 100 keV and 1 MeV. The MIRD 11 method for electron self-dose scaling was accurate for lower energies but began to break down at higher energies. The photon cross-dose scaling methodology developed in this study showed gains in accuracy of up to 9% for actual patient studies, and the electron cross-dose scaling methodology showed gains in accuracy up to 9% as well when only the bremsstrahlung component of the cross-dose was scaled. These dose scaling methods are readily available for incorporation into internal dosimetry software for diagnostic phantom-based organ dosimetry.

Individualized adjustments to reference phantom internal organ dosimetry-scaling factors given knowledge of patient internal anatomy.

PubMed

Wayson, Michael B; Bolch, Wesley E

2018-04-13

Various computational tools are currently available that facilitate patient organ dosimetry in diagnostic nuclear medicine, yet they are typically restricted to reporting organ doses to ICRP-defined reference phantoms. The present study, while remaining computational phantom based, provides straightforward tools to adjust reference phantom organ dose for both internal photon and electron sources. A wide variety of monoenergetic specific absorbed fractions were computed using radiation transport simulations for tissue spheres of varying size and separation distance. Scaling methods were then constructed for both photon and electron self-dose and cross-dose, with data validation provided from patient-specific voxel phantom simulations, as well as via comparison to the scaling methodology given in MIRD Pamphlet No. 11. Photon and electron self-dose was found to be dependent on both radiation energy and sphere size. Photon cross-dose was found to be mostly independent of sphere size. Electron cross-dose was found to be dependent on sphere size when the spheres were in close proximity, owing to differences in electron range. The validation studies showed that this dataset was more effective than the MIRD 11 method at predicting patient-specific photon doses for at both high and low energies, but gave similar results at photon energies between 100 keV and 1 MeV. The MIRD 11 method for electron self-dose scaling was accurate for lower energies but began to break down at higher energies. The photon cross-dose scaling methodology developed in this study showed gains in accuracy of up to 9% for actual patient studies, and the electron cross-dose scaling methodology showed gains in accuracy up to 9% as well when only the bremsstrahlung component of the cross-dose was scaled. These dose scaling methods are readily available for incorporation into internal dosimetry software for diagnostic phantom-based organ dosimetry.

Development of a paediatric population-based model of the pharmacokinetics of rivaroxaban.

PubMed

Willmann, Stefan; Becker, Corina; Burghaus, Rolf; Coboeken, Katrin; Edginton, Andrea; Lippert, Jörg; Siegmund, Hans-Ulrich; Thelen, Kirstin; Mück, Wolfgang

2014-01-01

Venous thromboembolism has been increasingly recognised as a clinical problem in the paediatric population. Guideline recommendations for antithrombotic therapy in paediatric patients are based mainly on extrapolation from adult clinical trial data, owing to the limited number of clinical trials in paediatric populations. The oral, direct Factor Xa inhibitor rivaroxaban has been approved in adult patients for several thromboembolic disorders, and its well-defined pharmacokinetic and pharmacodynamic characteristics and efficacy and safety profiles in adults warrant further investigation of this agent in the paediatric population. The objective of this study was to develop and qualify a physiologically based pharmacokinetic (PBPK) model for rivaroxaban doses of 10 and 20 mg in adults and to scale this model to the paediatric population (0-18 years) to inform the dosing regimen for a clinical study of rivaroxaban in paediatric patients. Experimental data sets from phase I studies supported the development and qualification of an adult PBPK model. This adult PBPK model was then scaled to the paediatric population by including anthropometric and physiological information, age-dependent clearance and age-dependent protein binding. The pharmacokinetic properties of rivaroxaban in virtual populations of children were simulated for two body weight-related dosing regimens equivalent to 10 and 20 mg once daily in adults. The quality of the model was judged by means of a visual predictive check. Subsequently, paediatric simulations of the area under the plasma concentration-time curve (AUC), maximum (peak) plasma drug concentration (C max) and concentration in plasma after 24 h (C 24h) were compared with the adult reference simulations. Simulations for AUC, C max and C 24h throughout the investigated age range largely overlapped with values obtained for the corresponding dose in the adult reference simulation for both body weight-related dosing regimens. However, pharmacokinetic values in infants and preschool children (body weight <40 kg) were lower than the 90 % confidence interval threshold of the adult reference model and, therefore, indicated that doses in these groups may need to be increased to achieve the same plasma levels as in adults. For children with body weight between 40 and 70 kg, simulated plasma pharmacokinetic parameters (C max, C 24h and AUC) overlapped with the values obtained in the corresponding adult reference simulation, indicating that body weight-related exposure was similar between these children and adults. In adolescents of >70 kg body weight, the simulated 90 % prediction interval values of AUC and C 24h were much higher than the 90 % confidence interval of the adult reference population, owing to the weight-based simulation approach, but for these patients rivaroxaban would be administered at adult fixed doses of 10 and 20 mg. The paediatric PBPK model developed here allowed an exploratory analysis of the pharmacokinetics of rivaroxaban in children to inform the dosing regimen for a clinical study in paediatric patients.

Issues in Sexuality for Adolescents with Chronic Illnesses and Disabilities. CYDLINE Reviews.

ERIC Educational Resources Information Center

Minnesota Univ., Minneapolis. National Center for Youth with Disabilities.

This annotated bibliography focuses on sexuality issues regarding adolescents and young adults with disabilities and chronic illnesses. The resources are grouped into the following categories: psychosocial development (23 references); attitudes and knowledge (11 references); sex education (34 references); sexual abuse (four references);…

Attitudes toward Younger and Older Adults: The German Aging Semantic Differential

ERIC Educational Resources Information Center

Gluth, Sebastian; Ebner, Natalie C.; Schmiedek, Florian

2010-01-01

The present study used the German Aging Semantic Differential (ASD) to assess attitudes toward younger and older adults in a heterogeneous sample of n = 151 younger and n = 143 older adults. The questionnaire was administered in two versions, one referring to the evaluation of younger adults, the other to the evaluation of older adults.…

Grassroots Approaches to Combatting Poverty through Adult Education. Supplement to Adult Education and Development. No. 34.

ERIC Educational Resources Information Center

Duke, Chris; And Others

1990-01-01

This supplement to "Adult Education and Development," a journal for adult education in Africa, Asia, and Latin America, refers to and is intended as a companion volume to "Combatting Poverty through Adult Education: National Development Strategies" (Croom Helm 1985). In addition to an introductory chapter and a conclusion, this…

A Guide to Basic Taxonomic Literature for the Genera of North American Chironomidae (Diptera) - Adults, Pupae, and Larvae. Bulletin No. 447.

ERIC Educational Resources Information Center

Simpson, Karl W.

A generic list of North American Chironomidae (Diptera) is presented to help aquatic biologists quickly locate important taxonomic references for the adults, larvae, and pupae of each genus. The list (in chart format) includes literature published through 1981. When recent literature is available, older references are omitted, since the purpose of…

Influence of Verbal and Nonverbal References to Print on Preschoolers' Visual Attention to Print during Storybook Reading

ERIC Educational Resources Information Center

Justice, Laura M.; Pullen, Paige C.; Pence, Khara

2008-01-01

How much do preschool children look at print within storybooks when adults read to them? This study sought to answer this question as well as to examine the effects of adult verbal and nonverbal references to print on children's visual attention to print during storybook reading. Forty-four preschool-aged children participated in this study…

Inhalation dose assessment of indoor radon progeny using biokinetic and dosimetric modeling and its application to Jordanian population.

PubMed

Al-Jundi, J; Li, W B; Abusini, M; Tschiersch, J; Hoeschen, C; Oeh, U

2011-06-01

High indoor radon concentrations in Jordan result in internal exposures of the residents due to the inhalation of radon and its short-lived progeny. It is therefore important to quantify the annual effective dose and further the radiation risk to the radon exposure. This study describes the methodology and the biokinetic and dosimetric models used for calculation of the inhalation doses exposed to radon progeny. The regional depositions of aerosol particles in the human respiratory tract were firstly calculated. For the attached progeny, the activity median aerodynamic diameters of 50 nm, 230 nm and 2500 nm were chosen to represent the nucleation, accumulation and coarse modes of the aerosol particles, respectively. For the unattached progeny, the activity median thermodynamic diameter of 1 nm was chosen to represent the free progeny nuclide in the room air. The biokinetic models developed by the International Commission on Radiological Protection (ICRP) were used to calculate the nuclear transformations of radon progeny in the human body, and then the dosimetric model was applied to estimate the organ equivalent doses and the effective doses with the specific effective energies derived from the mathematical anthropomorphic phantoms. The dose conversion coefficient estimated in this study was 15 mSv WLM(-1) which was in the range of the values of 6-20 mSv WLM(-1) reported by other investigators. Implementing the average indoor radon concentration in Jordan, the annual effective doses were calculated to be 4.1 mSv y(-1) and 0.08 mSv y(-1) due to the inhalation of radon progeny and radon gas, respectively. The total annual effective dose estimated for Jordanian population was 4.2 mSv y(-1). This high annual effective dose calculated by the dosimetric approach using ICRP biokinetic and dosimetric models resulted in an increase of a factor of two in comparison to the value by epidemiological study. This phenomenon was presented by the ICRP in its new published statement on radon. Copyright © 2011 Elsevier Ltd. All rights reserved.

Quantifying annual internal effective 137Cesium dose utilizing direct body-burden measurement and ecological dose modeling.

PubMed

Jelin, Benjamin A; Sun, Wenjie; Kravets, Alexandra; Naboka, Maryna; Stepanova, Eugenia I; Vdovenko, Vitaliy Y; Karmaus, Wilfried J; Lichosherstov, Alex; Svendsen, Erik R

2016-11-01

The Chernobyl Nuclear Power Plant (CNPP) accident represents one of the most significant civilian releases of 137 Cesium ( 137 Cs, radiocesium) in human history. In the Chernobyl-affected region, radiocesium is considered to be the greatest on-going environmental hazard to human health by radiobiologists and public health scientists. The goal of this study was to characterize dosimetric patterns and predictive factors for whole-body count (WBC)-derived radiocesium internal dose estimations in a CNPP-affected children's cohort, and cross-validate these estimations with a soil-based ecological dose estimation model. WBC data were used to estimate the internal effective dose using the International Commission on Radiological Protection (ICRP) 67 dose conversion coefficient for 137 Cs and MONDAL Version 3.01 software. Geometric mean dose estimates from each model were compared utilizing paired t-tests and intra-class correlation coefficients. Additionally, we developed predictive models for WBC-derived dose estimation in order to determine the appropriateness of EMARC to estimate dose for this population. The two WBC-derived dose predictive models identified 137 Cs soil concentration (P<0.0001) as the strongest predictor of annual internal effective dose from radiocesium validating the use of the soil-based EMARC model. The geometric mean internal effective dose estimate of the EMARC model (0.183 mSv/y) was the highest followed by the ICRP 67 dose estimates (0.165 mSv/y) and the MONDAL model estimates (0.149 mSv/y). All three models yielded significantly different geometric mean dose (P<0.05) estimates for this cohort when stratified by sex, age at time of exam and season of exam, except for the mean MONDAL and EMARC estimates for 15- and 16-year olds and mean ICRP and MONDAL estimates for children examined in Winter. Further prospective and retrospective radio-epidemiological studies utilizing refined WBC measurements and ecological model dose estimations, in conjunction with findings from animal toxicological studies, should help elucidate possible deterministic radiogenic health effects associated with chronic low-dose internal exposure to 137 Cs.

Functional Neuroimaging of Self-Referential Encoding with Age

PubMed Central

Gutchess, Angela H.; Kensinger, Elizabeth A.; Schacter, Daniel L.

2009-01-01

Aging impacts memory formation and the engagement of frontal and medial temporal regions. However, much of the research to date has focused on the encoding of neutral verbal and visual information. The present fMRI study investigated age differences in a social encoding task while participants made judgments about the self or another person. Although previous studies identified an intact self-reference effect with age, subserved by robust engagement of medial prefrontal cortex (mPFC) by both young and older adults, we identified a number of age differences. In regions including superior mPFC, inferior prefrontal cortex, and anterior and posterior cingulate cortex, young and older adults exhibited reversals in the pattern of activity for self and other conditions. Whereas young primarily evidenced subsequent forgetting effects in the self-reference condition, older adults demonstrated subsequent memory effects in the other-reference condition. These results indicate fundamental differences across the age groups in the engagement of elaborative encoding processes. We suggest that older adults may encode information about the self in a more normative manner, whereas young adults focus on encoding the unique aspects of the self and distinguishing the self from others. PMID:19765600

Clinical-Functional Vulnerability Index-20 (IVCF-20): rapid recognition of frail older adults.

PubMed

Moraes, Edgar Nunes de; Carmo, Juliana Alves do; Moraes, Flávia Lanna de; Azevedo, Raquel Souza; Machado, Carla Jorge; Montilla, Dalia Elena Romero

2016-12-22

To evaluate the adequacy of the Clinical-Functional Vulnerability Index-20, a rapid triage instrument to test vulnerability in Brazilian older adults, for the use in primary health care. The study included convenience sample of 397 patients aged older than or equal to 60 years attended at Centro de Referência para o Idoso (Reference Center for Older Adults) and of 52 older adults the same age attended at the community. The results of the questionnaire, consisting of 20 questions, were compared with those of the Comprehensive Geriatric Assessment, considered a reference for identifying frail older adults. Spearman's correlation was evaluated in the Clinical-Functional Vulnerability Index-20 with the Comprehensive Geriatric Assessment; the validity was verified by the area under the ROC curve; reliability was estimated by the percentage of agreement among evaluators and by the kappa coefficient, both with quadratic weighted. The cut-off point was obtained based on the higher accuracy criterion. Cronbach's alpha, a measure of internal consistency, was estimated. The Spearman's correlation coefficient was high and positive for both groups (0.792 for older adults attended at the Reference Center and 0.305 for older adults from the community [p < 0.001]). The area under the ROC curve for older adults attended at the Reference Center was substantial (0.903). The cut-off point obtained was six, and older adults with scores in Clinical-Functional Vulnerability Index-20 above that value had strong possibility of being frail. For older adults from the community, the quadratic weighted agreement among evaluators was 99.5%, and the global quadratic weighted kappa coefficient was 0.94. Cronbach's alpha was high for older adults attended at the Reference Center (0.861) and those attended at the community (0.740). The Clinical-Functional Vulnerability Index-20 questionnaire, in the sample examined, turned out to be positively correlated with the Comprehensive Geriatric Assessment, in addition to the results indicating a high degree of validity and reliability. Thus, the Clinical-Functional Vulnerability Index-20 proves to be viable as a triage instrument in the primary health care that identifies frail older adults (older adults at risk of weakening and frail older adults). Avaliar a adequação do Índice de Vulnerabilidade Clínico-Funcional-20 , instrumento de triagem rápida de vulnerabilidade em idosos brasileiros, para utilização pela atenção básica. O estudo incluiu amostra de conveniência de 397 pacientes com idade maior ou igual a 60 anos atendidos em um Centro de Referência para o Idoso e de 52 idosos da mesma idade atendidos na comunidade. Os resultados do questionário, constituído por 20 perguntas, foram comparados com aqueles da Avaliação Geriátrica Ampla, considerada referência para identificação do idoso frágil. Foi avaliada a correlação de Spearman do Índice de Vulnerabilidade Clínico-Funcional-20 com a Avaliação Geriátrica Ampla; a validade foi verificada pela área sob a curva ROC; a confiabilidade foi estimada pelo percentual de concordância entre avaliadores e coeficiente kappa, ambos com ponderação quadrática. Obteve-se ponto de corte com base no critério de maior acurácia. O alfa de Cronbach, medida de consistência interna, foi calculado. O coeficiente de correlação de Spearman foi elevado e positivo em ambos os grupos (0,792 para idosos atendidos no Centro de Referência para o Idoso e 0,305 para idosos da comunidade [p < 0,001]). A área sob a curva ROC para idosos atendidos no Centro de Referência para o Idoso foi substancial (0,903). O ponto de corte obtido foi seis e idosos com pontuação no Índice de Vulnerabilidade Clínico-Funcional-20 acima desse valor tinham forte possibilidade de serem frágeis. Para idosos da comunidade, a concordância ponderada quadrática entre avaliadores foi 99,5% e o coeficiente kappa ponderado quadrático global, 0,94. O alfa de Cronbach foi elevado para idosos atendidos no Centro de Referência para o Idoso (0,861) e da comunidade (0,740). O questionário do Índice de Vulnerabilidade Clínico-Funcional-20, na amostra analisada, mostrou ser positivamente correlacionado com a Avaliação Geriátrica Ampla, além de os resultados indicarem alto grau de validade e confiabilidade. Assim, o Índice de Vulnerabilidade Clínico-Funcional-20 se mostra viável como instrumento de rastreio na atenção básica que identifica o idoso com fragilidade (idoso em risco de fragilização e idoso frágil).

Radon decay products in realistic living rooms and their activity distributions in human respiratory system.

PubMed

Mohery, M; Abdallah, A M; Baz, S S; Al-Amoudi, Z M

2014-12-01

In this study, the individual activity concentrations of attached short-lived radon decay products ((218)Po, (214)Pb and (214)Po) in aerosol particles were measured in ten poorly ventilated realistic living rooms. Using standard methodologies, the samples were collected using a filter holder technique connected with alpha-spectrometric. The mean value of air activity concentration of these radionuclides was found to be 5.3±0.8, 4.5±0.5 and 3.9±0.4 Bq m(-3), respectively. Based on the physical properties of the attached decay products and physiological parameters of light work activity for an adult human male recommended by ICRP 66 and considering the parameters of activity size distribution (AMD = 0.25 μm and σ(g) = 2.5) given by NRC, the total and regional deposition fractions in each airway generation could be evaluated. Moreover, the total and regional equivalent doses in the human respiratory tract could be estimated. In addition, the surface activity distribution per generation is calculated for the bronchial region (BB) and the bronchiolar region (bb) of the respiratory system. The maximum values of these activities were found in the upper bronchial airway generations. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Pediatric Phantom Dosimetry of Kodak 9000 Cone-beam Computed Tomography.

PubMed

Yepes, Juan F; Booe, Megan R; Sanders, Brian J; Jones, James E; Ehrlich, Ygal; Ludlow, John B; Johnson, Brandon

2017-05-15

The purpose of the study was to evaluate the radiation dose of the Kodak 9000 cone-beam computed tomography (CBCT) device for different anatomical areas using a pediatric phantom. Absorbed doses resulting from maxillary and mandibular region three by five cm CBCT volumes of an anthropomorphic 10-year-old child phantom were acquired using optical stimulated dosimetry. Equivalent doses were calculated for radiosensitive tissues in the head and neck area, and effective dose for maxillary and mandibular examinations were calculated following the 2007 recommendations of the International Commission on Radiological Protection (ICRP). Of the mandibular scans, the salivary glands had the highest equivalent dose (1,598 microsieverts [μSv]), followed by oral mucosa (1,263 μSv), extrathoracic airway (pharynx, larynx, and trachea; 859 μSv), and thyroid gland (578 μSv). For the maxilla, the salivary glands had the highest equivalent dose (1,847 μSv), followed closely by oral mucosa (1,673 μSv), followed by the extrathoracic airway (pharynx, larynx, and trachea; 1,011 μSv) and lens of the eye (202 μSv). Compared to previous research of the Kodak 9000, completed with the adult phantom, a child receives one to three times more radiation for mandibular scans and two to 10 times more radiation for maxillary scans.

First Definition of Reference Intervals of Liver Function Tests in China: A Large-Population-Based Multi-Center Study about Healthy Adults

PubMed Central

Zhang, Chuanbao; Guo, Wei; Huang, Hengjian; Ma, Yueyun; Zhuang, Junhua; Zhang, Jie

2013-01-01

Background Reference intervals of Liver function tests are very important for the screening, diagnosis, treatment, and monitoring of liver diseases. We aim to establish common reference intervals of liver function tests specifically for the Chinese adult population. Methods A total of 3210 individuals (20–79 years) were enrolled in six representative geographical regions in China. Analytes of ALT, AST, GGT, ALP, total protein, albumin and total bilirubin were measured using three analytical systems mainly used in China. The newly established reference intervals were based on the results of traceability or multiple systems, and then validated in 21 large hospitals located nationwide qualified by the National External Quality Assessment (EQA) of China. Results We had been established reference intervals of the seven liver function tests for the Chinese adult population and found there were apparent variances of reference values for the variables for partitioning analysis such as gender(ALT, GGT, total bilirubin), age(ALP, albumin) and region(total protein). More than 86% of the 21 laboratories passed the validation in all subgroup of reference intervals and overall about 95.3% to 98.8% of the 1220 validation results fell within the range of the new reference interval for all liver function tests. In comparison with the currently recommended reference intervals in China, the single side observed proportions of out of range of reference values from our study for most of the tests deviated significantly from the nominal 2.5% such as total bilirubin (15.2%), ALP (0.2%), albumin (0.0%). Most of reference intervals in our study were obviously different from that of other races. Conclusion These used reference intervals are no longer applicable for the current Chinese population. We have established common reference intervals of liver function tests that are defined specifically for Chinese population and can be universally used among EQA-approved laboratories located all over China. PMID:24058449

Sustained and Focused Attention Deficits in Adult ADHD

ERIC Educational Resources Information Center

Marchetta, Natalie D. J.; Hurks, Petra P. M.; De Sonneville, Leo M. J.; Krabbendam, Lydia; Jolles, Jelle

2008-01-01

Objective: To examine the specificity of deficits in focused attention and sustained attention in adults with ADHD and to evaluate the effect of comorbidity. Method: Twenty-eight adults with ADHD without comorbidity were compared with 28 ADHD outpatients with comorbidity. Two control groups were used: 68 adults referred for ADHD but with another…

Learning Resources Evaluations Manual.

ERIC Educational Resources Information Center

Nunes, Evelyn H., Ed.

This manual contains evaluations of 196 instructional products listed in Virginia's Adult Basic Education Curricula Resource Catalog. It is intended as a convenient reference manual for making informed decisions concerning materials for adult learners in adult basic education, English-as-a-Second-Language instruction, and general educational…

Does Executive Functioning (EF) Predict Depression in Clinic-Referred Adults?: EF Tests vs. Rating Scales

PubMed Central

Knouse, Laura E.; Barkley, Russell A.; Murphy, Kevin R.

2012-01-01

Background Deficits in executive functioning (EF) are implicated in neurobiological and cognitive-processing theories of depression. EF deficits are also associated with Attention-deficit/hyperactivity disorder (ADHD) in adults, who are also at increased risk for depressive disorders. Given debate about the ecological validity of laboratory measures of EF, we investigated the relationship between depression diagnoses and symptoms and EF as measured by both rating scales and tests in a sample of adults referred for evaluation of adult ADHD. Method Data from two groups of adults recruited from an ADHD specialty clinic were analyzed together: Adults diagnosed with ADHD (N=146) and a clinical control group of adults referred for adult ADHD assessment but not diagnosed with the disorder ADHD (N=97). EF was assessed using a rating scale of EF deficits in daily life and a battery of tests tapping various EF constructs. Depression was assessed using current and lifetime SCID diagnoses (major depression, dysthymia) and self-report symptom ratings. Results EF as assessed via rating scale predicted depression across measures even when controlling for current anxiety and impairment. Self-Management to Time and Self-Organization and Problem-Solving showed the most robust relationships. EF tests were weakly and inconsistently related to depression measures. Limitations Prospective studies are needed to rigorously evaluate EF problems as true risk factors for depressive onset. Conclusions EF problems in everyday life were important predictors of depression. Researchers and clinicians should consistently assess for the ADHD-depression comorbidity. Clinicians should consider incorporating strategies to address EF deficits when treating people with depression. PMID:22858220

The biomedical piglet: establishing reference intervals for haematology and clinical chemistry parameters of two age groups with and without iron supplementation.

PubMed

Ventrella, Domenico; Dondi, Francesco; Barone, Francesca; Serafini, Federica; Elmi, Alberto; Giunti, Massimo; Romagnoli, Noemi; Forni, Monica; Bacci, Maria L

2017-01-17

The similarities between swine and humans in physiological and genomic patterns, and the great correlation in size and anatomy, make pigs extremely useful in preclinical studies. New-born piglets can represent a model for congenital and genetic diseases in new-born children. It is known that piglets may have significant differences in clinicopathological results compared to adult pigs. Therefore, adult laboratory reference intervals cannot be applied to piglets. The aim of this study was to compare haematological and chemical variables in piglets of two ages and determinate age-related reference intervals for commercial hybrid young pigs. Blood samples were collected under general anaesthesia from 130 animals divided into five- (P5) and 30- (P30) day-old piglets. Only P30 animals were treated with parenteral iron after birth. Samples were analysed using automated haematology (ADVIA 2120) and chemistry analysers, and age-related reference intervals were calculated. Significant higher values of RBC, Hb and HCT were observed in P30 animals when compared to P5, with an opposite trend for MCV. These results were associated with a reduction of the RBC regeneration process and the thrombopoietic response. The TSAT and TIBC were significantly higher in P30 compared to P5; however, piglets remained iron deficient compared to adult reference intervals reported previously. In conclusion, this paper emphasises the high variability occurring in clinicopathological variables between new-born and 30-day-old pigs, and between piglets and adult pigs. This study provides valuable reference data for piglets at precise ages and could be used in the future as historical control improving the Reduction in animal experiments, as suggested by the 3Rs principle.

Accuracy of burn size estimation in patients transferred to adult Burn Units in Sydney, Australia: an audit of 698 patients.

PubMed

Harish, Varun; Raymond, Andrew P; Issler, Andrea C; Lajevardi, Sepehr S; Chang, Ling-Yun; Maitz, Peter K M; Kennedy, Peter

2015-02-01

The purpose of this study was to compare burn size estimation between referring centres and Burn Units in adult patients transferred to Burn Units in Sydney, Australia. A review of all adults transferred to Burn Units in Sydney, Australia between January 2009 and August 2013 was performed. The TBSA estimated by the referring institution was compared with the TBSA measured at the Burns Unit. There were 698 adults transferred to a Burns Unit. Equivalent TBSA estimation between the referring hospital and Burns Unit occurred in 30% of patients. Overestimation occurred at a ratio exceeding 3:1 with respect to underestimation, with the difference between the referring institutions and Burns Unit estimation being statistically significant (P<0.001). Significant overestimation occurs in the early transfer of burn-injured patients as well as in patients transferred more than 48h after the burn (P<0.005). Underestimation occurs with less frequency but rises with increasing time after the burn (P<0.005) and with increasing TBSA. Throughout the temporal spectrum of transferred patients, severe burns (≥20% TBSA) were found to have more satisfactory burn size estimations compared with less severe injuries (<20% TBSA; P<0.005). There are significant inaccuracies in burn size assessment by referring centres. The systemic tendency for overestimation occurs throughout the entire TBSA spectrum, and persists with increasing time after the burn. Underestimation occurs less frequently but rises with increasing time after the burn and with increasing TBSA. Severe burns (≥20% TBSA) are more accurately estimated by the referring hospital. The inaccuracies in burn size assessment have the potential to result in suboptimal treatment and inappropriate referral to specialised Burn Units. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

Monitoring Cosmic Radiation Risk: Comparisons between Observations and Predictive Codes for Naval Aviation

DTIC Science & Technology

2009-01-01

proton PARMA PHITS -based Analytical Radiation Model in the Atmosphere PCAIRE Predictive Code for Aircrew Radiation Exposure PHITS Particle and...radiation transport code utilized is called PARMA ( PHITS based Analytical Radiation Model in the Atmosphere) [36]. The particle fluxes calculated from the...same dose equivalent coefficient regulations from the ICRP-60 regulations. As a result, the transport codes utilized by EXPACS ( PHITS ) and CARI-6

Monitoring Cosmic Radiation Risk: Comparisons Between Observations and Predictive Codes for Naval Aviation

DTIC Science & Technology

2009-07-05

proton PARMA PHITS -based Analytical Radiation Model in the Atmosphere PCAIRE Predictive Code for Aircrew Radiation Exposure PHITS Particle and Heavy...transport code utilized is called PARMA ( PHITS based Analytical Radiation Model in the Atmosphere) [36]. The particle fluxes calculated from the input...dose equivalent coefficient regulations from the ICRP-60 regulations. As a result, the transport codes utilized by EXPACS ( PHITS ) and CARI-6 (PARMA

Characterization and validation of the thorax phantom Lungman for dose assessment in chest radiography optimization studies.

PubMed

Rodríguez Pérez, Sunay; Marshall, Nicholas William; Struelens, Lara; Bosmans, Hilde

2018-01-01

This work concerns the validation of the Kyoto-Kagaku thorax anthropomorphic phantom Lungman for use in chest radiography optimization. The equivalence in terms of polymethyl methacrylate (PMMA) was established for the lung and mediastinum regions of the phantom. Patient chest examination data acquired under automatic exposure control were collated over a 2-year period for a standard x-ray room. Parameters surveyed included exposure index, air kerma area product, and exposure time, which were compared with Lungman values. Finally, a voxel model was developed by segmenting computed tomography images of the phantom and implemented in PENELOPE/penEasy Monte Carlo code to compare phantom tissue-equivalent materials with materials from ICRP Publication 89 in terms of organ dose. PMMA equivalence varied depending on tube voltage, from 9.5 to 10.0 cm and from 13.5 to 13.7 cm, for the lungs and mediastinum regions, respectively. For the survey, close agreement was found between the phantom and the patients' median values (deviations lay between 8% and 14%). Differences in lung doses, an important organ for optimization in chest radiography, were below 13% when comparing the use of phantom tissue-equivalent materials versus ICRP materials. The study confirms the value of the Lungman for chest optimization studies.

Age and gender specific biokinetic model for strontium in humans

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shagina, N. B.; Tolstykh, E. I.; Degteva, M. O.

A biokinetic model for strontium in humans is necessary for quantification of internal doses due to strontium radioisotopes. The ICRP-recommended biokinetic model for strontium has limitation for use in a population study, because it is not gender specific and does not cover all age ranges. The extensive Techa River data set on 90Sr in humans (tens of thousands of measurements) is a unique source of data on long-term strontium retention for men and women of all ages at intake. These, as well as published data, were used for evaluation of age- and gender-specific parameters for a new compartment biokinetic modelmore » for strontium (Sr-AGe model). The Sr-AGe model has similar structure as the ICRP model for the alkaline earth elements. The following parameters were mainly reevaluated: gastro-intestinal absorption and parameters related to the processes of bone formation and resorption defining calcium and strontium transfers in skeletal compartments. The Sr-AGe model satisfactorily describes available data sets on strontium retention for different kinds of intake (dietary and intravenous) at different ages (0–80 years old) and demonstrates good agreement with data sets for different ethnic groups. The Sr-AGe model can be used for dose assessment in epidemiological studies of general population exposed to ingested strontium radioisotopes.« less

Evaluation of lens absorbed dose with Cone Beam IGRT procedures.

PubMed

Palomo, R; Pujades, M C; Gimeno-Olmos, J; Carmona, V; Lliso, F; Candela-Juan, C; Vijande, J; Ballester, F; Perez-Calatayud, J

2015-12-01

The purpose of this work is to evaluate the absorbed dose to the eye lenses due to the cone beam computed tomography (CBCT) system used to accurately position the patient during head-and-neck image guided procedures. The on-board imaging (OBI) systems (v.1.5) of Clinac iX and TrueBeam (Varian) accelerators were used to evaluate the imparted dose to the eye lenses and some additional points of the head. All CBCT scans were acquired with the Standard-Dose Head protocol from Varian. Doses were measured using thermoluminescence dosimeters (TLDs) placed in an anthropomorphic phantom. TLDs were calibrated at the beam quality used to reduce their energy dependence. Average dose to the lens due to the OBI systems of the Clinac iX and the TrueBeam were 0.71  ±  0.07 mGy/CBCT and 0.70  ±  0.08 mGy/CBCT, respectively. The extra absorbed dose received by the eye lenses due to one CBCT acquisition with the studied protocol is far below the 500 mGy threshold established by ICRP for cataract formation (ICRP 2011 Statement on Tissue Reactions). However, the incremental effect of several CBCT acquisitions during the whole treatment should be taken into account.

Weighting factors for radiation quality: how to unite the two current concepts.

PubMed

Kellerer, Albrecht M

2004-01-01

The quality factor, Q(L), used to be the universal weighting factor to account for radiation quality, until--in its 1991 Recommendations--the ICRP established a dichotomy between 'computable' and 'measurable' quantities. The new concept of the radiation weighting factor, w(R), was introduced for use with the 'computable' quantities, such as the effective dose, E. At the same time, the application of Q(L) was restricted to 'measurable' quantities, such as the operational quantities ambient dose equivalent or personal dose equivalent. The result has been a dual system of incoherent dosimetric quantities. The most conspicuous inconsistency resulted for neutrons, for which the new concept of wR had been primarily designed. While its definition requires an accounting for the gamma rays produced by neutron capture in the human body, this effect is not adequately reflected in the numerical values of wR, which are now suitable for mice, but are--at energies of the incident neutrons below 1 MeV--conspicuously too large for man. A recent Report 92 to ICRP has developed a proposal to correct the current imbalance and to define a linkage between the concepts Q(L) and wR. The proposal is here considered within a broader assessment of the rationale that led to the current dual system of dosimetric quantities.

Nuclear decay data files of the Dosimetry Research Group

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eckerman, K.F.; Westfall, R.J.; Ryman, J.C.

1993-12-01

This report documents the nuclear decay data files used by the Dosimetry Research Group at Oak Ridge National Laboratory and the utility DEXRAX which provides access to the files. The files are accessed, by nuclide, to extract information on the intensities and energies of the radiations associated with spontaneous nuclear transformation of the radionuclides. In addition, beta spectral data are available for all beta-emitting nuclides. Two collections of nuclear decay data are discussed. The larger collection contains data for 838 radionuclides, which includes the 825 radionuclides assembled during the preparation of Publications 30 and 38 of the International Commission onmore » Radiological Protection (ICRP) and 13 additional nuclides evaluated in preparing a monograph for the Medical Internal Radiation Dose (MIRD) Committee of the Society of Nuclear Medicine. The second collection is composed of data from the MIRD monograph and contains information for 242 radionuclides. Abridged tabulations of these data have been published by the ICRP in Publication 38 and by the Society of Nuclear Medicine in a monograph entitled ``MIRD: Radionuclide Data and Decay Schemes.`` The beta spectral data reported here have not been published by either organization. Electronic copies of the files and the utility, along with this report, are available from the Radiation Shielding Information Center at Oak Ridge National Laboratory.« less

Hanford Technical Basis for Multiple Dosimetry Effective Dose Methodology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hill, Robin L.; Rathbone, Bruce A.

2010-08-01

The current method at Hanford for dealing with the results from multiple dosimeters worn during non-uniform irradiation is to use a compartmentalization method to calculate the effective dose (E). The method, as documented in the current version of Section 6.9.3 in the 'Hanford External Dosimetry Technical Basis Manual, PNL-MA-842,' is based on the compartmentalization method presented in the 1997 ANSI/HPS N13.41 standard, 'Criteria for Performing Multiple Dosimetry.' With the adoption of the ICRP 60 methodology in the 2007 revision to 10 CFR 835 came changes that have a direct affect on the compartmentalization method described in the 1997 ANSI/HPS N13.41more » standard, and, thus, to the method used at Hanford. The ANSI/HPS N13.41 standard committee is in the process of updating the standard, but the changes to the standard have not yet been approved. And, the drafts of the revision of the standard tend to align more with ICRP 60 than with the changes specified in the 2007 revision to 10 CFR 835. Therefore, a revised method for calculating effective dose from non-uniform external irradiation using a compartmental method was developed using the tissue weighting factors and remainder organs specified in 10 CFR 835 (2007).« less

A study of indoor radon, thoron and their exhalation rates in the environment of Fazilka district, Punjab, India

NASA Astrophysics Data System (ADS)

Narang, Saurabh; Kumar, Deepak; Sharma, Dinesh Kumar; Kumar, Ajay

2018-02-01

Over the last few decades, the study of radioactive radon gas has gained huge momentum due to its possible role in health related hazards. In the present work, pin-hole twin chamber single entrance dosimeters have been used for track measurements of radon and thoron. The annual average radon concentration varies from 50.3 to 204 Bq/m3 at all locations. Almost all the values are below the safe range provided by ICRP. Radon concentration is found to be higher in winter as compared to other seasons. Variation of radon with quality of dwellings is also discussed. The values of annual effective dose due to radon and thoron are also well within the range provided by ICRP and WHO. Radon and thoron exhalation rates are measured using SMART RnDuo monitor. The radon mass exhalation rates ranged from 11 to 71 mBq/kg/h while the thoron surface values ranged from 36 to 2048 Bq/m2/h. All the values are on the lower side. A weak correlation is found between radon and thoron concentrations and their exhalation rates. When compared with the values of other parts of northern India, the values of present investigation are on higher side.

External dose-rate conversion factors of radionuclides for air submersion, ground surface contamination and water immersion based on the new ICRP dosimetric setting.

PubMed

Yoo, Song Jae; Jang, Han-Ki; Lee, Jai-Ki; Noh, Siwan; Cho, Gyuseong

2013-01-01

For the assessment of external doses due to contaminated environment, the dose-rate conversion factors (DCFs) prescribed in Federal Guidance Report 12 (FGR 12) and FGR 13 have been widely used. Recently, there were significant changes in dosimetric models and parameters, which include the use of the Reference Male and Female Phantoms and the revised tissue weighting factors, as well as the updated decay data of radionuclides. In this study, the DCFs for effective and equivalent doses were calculated for three exposure settings: skyshine, groundshine and water immersion. Doses to the Reference Phantoms were calculated by Monte Carlo simulations with the MCNPX 2.7.0 radiation transport code for 26 mono-energy photons between 0.01 and 10 MeV. The transport calculations were performed for the source volume within the cut-off distances practically contributing to the dose rates, which were determined by a simplified calculation model. For small tissues for which the reduction of variances are difficult, the equivalent dose ratios to a larger tissue (with lower statistical errors) nearby were employed to make the calculation efficient. Empirical response functions relating photon energies, and the organ equivalent doses or the effective doses were then derived by the use of cubic-spline fitting of the resulting doses for 26 energy points. The DCFs for all radionuclides considered important were evaluated by combining the photon emission data of the radionuclide and the empirical response functions. Finally, contributions of accompanied beta particles to the skin equivalent doses and the effective doses were calculated separately and added to the DCFs. For radionuclides considered in this study, the new DCFs for the three exposure settings were within ±10 % when compared with DCFs in FGR 13.

External dose-rate conversion factors of radionuclides for air submersion, ground surface contamination and water immersion based on the new ICRP dosimetric setting

PubMed Central

Yoo, Song Jae; Jang, Han-Ki; Lee, Jai-Ki; Noh, Siwan; Cho, Gyuseong

2013-01-01

For the assessment of external doses due to contaminated environment, the dose-rate conversion factors (DCFs) prescribed in Federal Guidance Report 12 (FGR 12) and FGR 13 have been widely used. Recently, there were significant changes in dosimetric models and parameters, which include the use of the Reference Male and Female Phantoms and the revised tissue weighting factors, as well as the updated decay data of radionuclides. In this study, the DCFs for effective and equivalent doses were calculated for three exposure settings: skyshine, groundshine and water immersion. Doses to the Reference Phantoms were calculated by Monte Carlo simulations with the MCNPX 2.7.0 radiation transport code for 26 mono-energy photons between 0.01 and 10 MeV. The transport calculations were performed for the source volume within the cut-off distances practically contributing to the dose rates, which were determined by a simplified calculation model. For small tissues for which the reduction of variances are difficult, the equivalent dose ratios to a larger tissue (with lower statistical errors) nearby were employed to make the calculation efficient. Empirical response functions relating photon energies, and the organ equivalent doses or the effective doses were then derived by the use of cubic-spline fitting of the resulting doses for 26 energy points. The DCFs for all radionuclides considered important were evaluated by combining the photon emission data of the radionuclide and the empirical response functions. Finally, contributions of accompanied beta particles to the skin equivalent doses and the effective doses were calculated separately and added to the DCFs. For radionuclides considered in this study, the new DCFs for the three exposure settings were within ±10 % when compared with DCFs in FGR 13. PMID:23542764

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Choonsik; Kim, Kwang Pyo; Long, Daniel J.

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{sub vol} (mGy/100 mAs mGy) was established by coupling the CT scanner model with age-dependentmore » 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{sub 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{sub 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 several-fold when organs were partially included in the scan coverage. Second, selected organ doses from our calculations agreed to within 20% of values derived from empirical formulae based upon measured patient abdominal circumference. Third, the existing DLP-to-effective dose conversion coefficients tended to be smaller than values given in the present study for all examinations except head scans. Conclusions: A comprehensive organ/effective dose database was established to readily calculate doses for given patients undergoing different CT examinations. The comparisons of our results with the existing studies highlight that use of hybrid phantoms with realistic anatomy is important to improve the accuracy of CT organ dosimetry. The comprehensive pediatric dose data developed here are the first organ-specific pediatric CT scan database based on the realistic pediatric hybrid phantoms which are compliant with the reference data from the International Commission on Radiological Protection (ICRP). The organ dose database is being coupled with an adult organ dose database recently published as part of the development of a user-friendly computer program enabling rapid estimates of organ and effective dose doses for patients of any age, gender, examination types, and CT scanner model.« less

Development of a Radiation Dose Reporting Software for X-ray Computed Tomography (CT)

NASA Astrophysics Data System (ADS)

Ding, Aiping

X-ray computed tomography (CT) has experienced tremendous technological advances in recent years and has established itself as one of the most popular diagnostic imaging tools. While CT imaging clearly plays an invaluable role in modern medicine, its rapid adoption has resulted in a dramatic increase in the average medical radiation exposure to the worldwide and United States populations. Existing software tools for CT dose estimation and reporting are mostly based on patient phantoms that contain overly simplified anatomies insufficient in meeting the current and future needs. This dissertation describes the development of an easy-to-use software platform, “VirtualDose”, as a service to estimate and report the organ dose and effective dose values for patients undergoing the CT examinations. “VirtualDose” incorporates advanced models for the adult male and female, pregnant women, and children. To cover a large portion of the ignored obese patients that frequents the radiology clinics, a new set of obese male and female phantoms are also developed and applied to study the effects of the fat tissues on the CT radiation dose. Multi-detector CT scanners (MDCT) and clinical protocols, as well as the most recent effective dose algorithms from the International Commission on Radiological Protection (ICRP) Publication 103 are adopted in “VirtualDose” to keep pace with the MDCT development and regulatory requirements. A new MDCT scanner model with both body and head bowtie filter is developed to cover both the head and body scanning modes. This model was validated through the clinical measurements. A comprehensive slice-by-slice database is established by deriving the data from a larger number of single axial scans simulated on the patient phantoms using different CT bowtie filters, beam thicknesses, and different tube voltages in the Monte Carlo N-Particle Extended (MCNPX) code. When compared to the existing CT dose software packages, organ dose data in this software provides a better CT dose assessment by using anatomically realistic patient phantoms. All the related organ doses are incorporated into a standardized database compiled using Microsoft Structured Query Language (SQL) server 2008. Organ doses from contiguous axial or helical scans defined by a specific protocol can be rapidly obtained from the database. A next-generation software architecture and Active Server Pages (ASP) .NET framework are adopted to create a browser-hosted application to improve the user interactivity and reporting functionality including scanning parameter selection and organ dose reporting. “VirtualDose” has been developed as a web-based CT dose reporting platform to facilitate several important features including: (1) easy access via Internet; (2) no need for installation on the local computer; (3) a user-friendly, dynamic, browser-hosted graphical user interface; (4) use of advanced patient models for the adult male and female, pregnant women, children, and obese patient models; (5) adoption of modern CT scanners and protocols, as well as the most recent ICRP 103 effective dose algorithms; and (6) flexibility to manage and easily upgrade without impacting user’s usage.

Reference Values for Spirometry Derived Using Lambda, Mu, Sigma (LMS) Method in Korean Adults: in Comparison with Previous References.

PubMed

Jo, Bum Seak; Myong, Jun Pyo; Rhee, Chin Kook; Yoon, Hyoung Kyu; Koo, Jung Wan; Kim, Hyoung Ryoul

2018-01-15

The present study aimed to update the prediction equations for spirometry and their lower limits of normal (LLN) by using the lambda, mu, sigma (LMS) method and to compare the outcomes with the values of previous spirometric reference equations. Spirometric data of 10,249 healthy non-smokers (8,776 females) were extracted from the fourth and fifth versions of the Korea National Health and Nutrition Examination Survey (KNHANES IV, 2007-2009; V, 2010-2012). Reference equations were derived using the LMS method which allows modeling skewness (lambda [L]), mean (mu [M]), and coefficient of variation (sigma [S]). The outcome equations were compared with previous reference values. Prediction equations were presented in the following form: predicted value = e{a + b × ln(height) + c × ln(age) + M - spline}. The new predicted values for spirometry and their LLN derived using the LMS method were shown to more accurately reflect transitions in pulmonary function in young adults than previous prediction equations derived using conventional regression analysis in 2013. There were partial discrepancies between the new reference values and the reference values from the Global Lung Function Initiative in 2012. The results should be interpreted with caution for young adults and elderly males, particularly in terms of the LLN for forced expiratory volume in one second/forced vital capacity in elderly males. Serial spirometry follow-up, together with correlations with other clinical findings, should be emphasized in evaluating the pulmonary function of individuals. Future studies are needed to improve the accuracy of reference data and to develop continuous reference values for spirometry across all ages. © 2018 The Korean Academy of Medical Sciences.

Reference Services for the Adult Learner: Challenging Issues for the Traditional and Technological Era.

ERIC Educational Resources Information Center

Sarkodie-Mensah, Kwasi, Ed.

This book offers approaches for teaching adult patrons how and where to find information in libraries and through information services. It includes 34 papers, organized in seven sections, expressing the views of faculty, adult students, and administrators as well as librarians on theories of educational psychology that explain how adults learn.…

Semantic and self-referential processing of positive and negative trait adjectives in older adults

PubMed Central

Glisky, Elizabeth L.; Marquine, Maria J.

2008-01-01

The beneficial effects of self-referential processing on memory have been demonstrated in numerous experiments with younger adults but have rarely been studied in older individuals. In the present study we tested young people, younger-older adults, and older-older adults in a self-reference paradigm, and compared self-referential processing to general semantic processing. Findings indicated that older adults over the age of 75 and those with below average episodic memory function showed a decreased benefit from both semantic and self-referential processing relative to a structural baseline condition. However, these effects appeared to be confined to the shared semantic processes for the two conditions, leaving the added advantage for self-referential processing unaffected These results suggest that reference to the self engages qualitatively different processes compared to general semantic processing. These processes seem relatively impervious to age and to declining memory and executive function, suggesting that they might provide a particularly useful way for older adults to improve their memories. PMID:18608973

Hematologic and serum chemistry reference intervals for free-ranging lions (Panthera leo).

PubMed

Maas, Miriam; Keet, Dewald F; Nielen, Mirjam

2013-08-01

Hematologic and serum chemistry values are used by veterinarians and wildlife researchers to assess health status and to identify abnormally high or low levels of a particular blood parameter in a target species. For free-ranging lions (Panthera leo) information about these values is scarce. In this study 7 hematologic and 11 serum biochemistry values were evaluated from 485 lions from the Kruger National Park, South Africa. Significant differences between sexes and sub-adult (≤ 36 months) and adult (>36 months) lions were found for most of the blood parameters and separate reference intervals were made for those values. The obtained reference intervals include the means of the various blood parameter values measured in captive lions, except for alkaline phosphatase in the subadult group. These reference intervals can be utilized for free-ranging lions, and may likely also be used as reference intervals for captive lions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Referential choice across the lifespan: why children and elderly adults produce ambiguous pronouns

PubMed Central

Hendriks, Petra; Koster, Charlotte; Hoeks, John C.J.

2013-01-01

In this study, children, young adults and elderly adults were tested in production and comprehension tasks assessing referential choice. Our aims were (1) to determine whether speakers egocentrically base their referential choice on the preceding linguistic discourse or also take into account the perspective of a hypothetical listener and (2) whether the possible impact of perspective taking on referential choice changes with increasing age, with its associated changes in cognitive capacity. In the production task, participants described picture-based stories featuring two characters of the same gender, making it necessary to use unambiguous forms; in the comprehension task, participants interpreted potentially ambiguous pronouns at the end of similar orally presented stories. Young adults (aged 18–35) were highly sensitive to the informational needs of hypothetical conversational partners in their production and comprehension of referring expressions. In contrast, children (aged 4–7) did not take into account possible conversational partners and tended to use pronouns for all given referents, leading to the production of ambiguous pronouns that are unrecoverable for a listener. This was mirrored in the outcome of the comprehension task, where children were insensitive to the shift of discourse topic marked by the speaker. The elderly adults (aged 69–87) behaved differently from both young adults and children. They showed a clear sensitivity to the other person's perspective in both production and comprehension, but appeared to lack the necessary cognitive capacities to keep track of the prominence of discourse referents, producing more potentially ambiguous pronouns than young adults, though fewer than children. In conclusion then, referential choice seems to depend on perspective taking in language, which develops with increasing linguistic experience and cognitive capacity, but also on the ability to keep track of the prominence of discourse referents, which is gradually lost with older age. PMID:24771955

Online Reference Service--How to Begin: A Selected Bibliography.

ERIC Educational Resources Information Center

Shroder, Emelie J., Ed.

1982-01-01

Materials in this bibliography were selected and recommended by members of the Use of Machine-Assisted Reference in Public Libraries Committee, Reference and Adult Services Division, American Library Association. Topics include: financial aspects, equipment and communications considerations, comparing databases and database systems, advertising…

Understanding Adult Overweight and Obesity

MedlinePlus

... Step in the Right Direction Understanding Adult Overweight & Obesity View or Print All Sections Definition & Facts The terms “overweight” and “obesity” refer to body weight that is greater than ...

Age-specific MRI brain and head templates for healthy adults from 20 through 89 years of age

PubMed Central

Fillmore, Paul T.; Phillips-Meek, Michelle C.; Richards, John E.

2015-01-01

This study created and tested a database of adult, age-specific MRI brain and head templates. The participants included healthy adults from 20 through 89 years of age. The templates were done in five-year, 10-year, and multi-year intervals from 20 through 89 years, and consist of average T1W for the head and brain, and segmenting priors for gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF). It was found that age-appropriate templates provided less biased tissue classification estimates than age-inappropriate reference data and reference data based on young adult templates. This database is available for use by other investigators and clinicians for their MRI studies, as well as other types of neuroimaging and electrophysiological research.1 PMID:25904864

Assessment of a Professional Development Program on Adult Learning Theory

ERIC Educational Resources Information Center

Malik, Melinda

2016-01-01

Librarians at colleges and universities invested in graduate education must understand and incorporate adult learning theories in their reference and instruction interactions with graduate students to more effectively support the students' learning. After participating in a professional development program about adult learning theory, librarians…

Achieving Voice and Security in Colleges of Education.

ERIC Educational Resources Information Center

Day, Michael J.; Amstutz, Donna D.; Whitson, Donna L.

2001-01-01

Adult education graduate programs struggle to establish legitimacy in colleges of education. Tensions exist between K-12 teacher educators and adult educators over beliefs about knowledge, schools, learning, teaching, and resource allocation. Adult education faculty may choose to pursue idealism, isolation, or compromise. (Contains 18 references.)…

Screening for Learning Disabilities in Adult Basic Education Students

ERIC Educational Resources Information Center

Reynolds, Sharon L.; Johnson, Jerry D.; Salzman, James A.

2012-01-01

The extant literature offers little to describe the processes for screening students in adult basic education (ABE) programs for potential learning disabilities, referring adult students for diagnostic assessment, or barriers to obtaining diagnostic assessment for a learning disability. Without current documentation of a learning disability, ABE…

Health and Functional Status of Adults with Intellectual Disability Referred to the Specialist Health Care Setting: A Five-Year Experience

PubMed Central

Lee, L.; Rianto, J.; Raykar, V.; Creasey, H.; Waite, L.; Berry, A.; Xu, J.; Chenoweth, B.; Kavanagh, S.; Naganathan, V.

2011-01-01

Aims and Method. The Developmental Disability Database in the Department of Rehabilitation Medicine at a metropolitan hospital was audited for observations on adults with Intellectual Disability living in the local region (total population 180,000) who were seen in an identified multidisciplinary specialist clinic, during 2006–2010. Results. There were 162 people (representing half the known number of adults with Intellectual Disability living in the region): 77 females, 85 males, age range 16–86 years. The most common complex disabilities referred to the specialists in this clinic were epilepsy (52%), challenging or changing behavior (42%) and movement disorders (34%). Early onset dementia was a feature of the group (7%). The prevalence of prescription of medications for gastro-oesophageal reflux was high (36%) and similar to the numbers of people taking psychotropic medications. The rates of chronic cardiovascular disease (2%), chronic respiratory disease (10%) and generalised arthritis (11%) were low overall, but did rise with increasing age. Conclusions. Complex neurological disabilities are common, and chronic medical illnesses are uncommon in adults with Intellectual Disability referred to specialist clinicians in this region. A combined, coordinated, multidisciplinary clinic model addresses some of the barriers experienced by adults with Intellectual Disability in the secondary health system. PMID:22295183

The mental health of individuals referred for assessment of autism spectrum disorder in adulthood: A clinic report.

PubMed

Russell, Ailsa J; Murphy, Clodagh M; Wilson, Ellie; Gillan, Nicola; Brown, Cordelia; Robertson, Dene M; Craig, Michael C; Deeley, Quinton; Zinkstok, Janneke; Johnston, Kate; McAlonan, Grainne M; Spain, Deborah; Murphy, Declan Gm

2016-07-01

Growing awareness of autism spectrum disorders has increased the demand for diagnostic services in adulthood. High rates of mental health problems have been reported in young people and adults with autism spectrum disorder. However, sampling and methodological issues mean prevalence estimates and conclusions about specificity in psychiatric co-morbidity in autism spectrum disorder remain unclear. A retrospective case review of 859 adults referred for assessment of autism spectrum disorder compares International Classification of Diseases, Tenth Revision diagnoses in those that met criteria for autism spectrum disorder (n = 474) with those that did not (n = 385). Rates of psychiatric diagnosis (>57%) were equivalent across both groups and exceeded general population rates for a number of conditions. The prevalence of anxiety disorders, particularly obsessive compulsive disorder, was significantly higher in adults with autism spectrum disorder than adults without autism spectrum disorder. Limitations of this observational clinic study, which may impact generalisability of the findings, include the lack of standardised structured psychiatric diagnostic assessments by assessors blind to autism spectrum disorder diagnosis and inter-rater reliability. The implications of this study highlight the need for careful consideration of mental health needs in all adults referred for autism spectrum disorder diagnosis. © The Author(s) 2015.

Serum reference interval of ARCHITECT alpha-fetoprotein in healthy Chinese Han adults: Sub-analysis of a prospective multi-center study.

PubMed

Yan, Cunling; Yang, Jia; Wei, Lianhua; Hu, Jian; Song, Jiaqi; Wang, Xiaoqin; Han, Ruilin; Huang, Ying; Zhang, Wei; Soh, Andrew; Beshiri, Agim; Fan, Zhuping; Zheng, Yijie; Chen, Wei

2018-02-01

Alpha-fetoprotein (AFP) has been widely used in clinical practice for decades. However, large-scale survey of serum reference interval for ARCHITECT AFP is still absent in Chinese population. This study aimed to measure serum AFP levels in healthy Chinese Han subjects, which is a sub-analysis of an ongoing prospective, cross-sectional, multi-center study (ClinicalTrials.gov Identifier: NCT03047603). This analysis included a total of 530 participants (41.43±12.14years of age on average, 48.49% males), enrolled from 5 regional centers. Serum AFP level was measured by ARCHITECT immunoassay. Statistical analysis was performed using SAS 9.4 and R software. AFP distribution did not show significant correlation with age or sex. The overall median and interquartile range of AFP was 2.87 (2.09, 3.83) ng/mL. AFP level did not show a trend of increasing with age. The new reference interval was 2.0-7.07ng/mL (LOQ- 97.5th percentiles). The reference interval for ARCHITECT AFP is updated with the data of adequate number of healthy Han adults. This new reference interval is more practical and applicable in Chinese adults. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Professional Development in Adult Basic Education.

ERIC Educational Resources Information Center

Marceau, Georges

2003-01-01

Addresses the professional development needs of adult basic education instructors. Describes federal and state resources for professional development. Recommends field-based research, reflective practice, and learner-centered instruction. (Contains 15 references.) (SK)

Indicated prevention of adult obesity: reference data for weight normalization in overweight children

USDA-ARS?s Scientific Manuscript database

Background: Pediatric obesity is a major risk factor for adult obesity. Indicated prevention--that is, helping overweight or obese youth attain non-overweight status--has been suggested to prevent adult obesity. This study aimed to support the notion of indicated prevention by demonstrating that rel...

Interrupting Adult Learning through Online Pedagogy

ERIC Educational Resources Information Center

Stuart-Buttle, Ros

2014-01-01

This paper considers online pedagogy in relation to Christian adult learning and asks how this might be interpreted by theological educators. The online community of inquiry is proposed as one recognized pedagogical approach and illustrated by reference to a continuing professional development programme for online adult learners across the church…

Philosophical Issues in the Education of Adults.

ERIC Educational Resources Information Center

Lawson, K. H.

This book, which is intended primarily for students and others interested in the theory and practice of adult education, contains nine essays demonstrating how traditional adult education values that are derived from philosophies of "individualism" also imply a "public" dimension that is referred to as "mutuality" and manifested not only in the…

The Relationship of Parenting Styles to Commitment to the Church among Young Adults.

ERIC Educational Resources Information Center

Dudley, Roger L.; Wisbey, Randall L.

2000-01-01

Investigates the effects of parenting style experiences during childhood has on the religious commitment of young adults. Surveyed Seventh-day Adventist young adults (n=653) in United States and Canada. Reveals that the affectionate constraint parenting style produced the largest percentage of members. Includes references. (CMK)

Functional Impairment and Occupational Outcome in Adults with ADHD

ERIC Educational Resources Information Center

Gjervan, Bjorn; Torgersen, Terje; Nordahl, Hans M.; Rasmussen, Kirsten

2012-01-01

Objective: ADHD is associated with poor functional outcomes. The objectives were to investigate the prevalence of functional impairment and occupational status in a clinically referred sample of adults with ADHD and explore factors predicting occupational outcome. Method: A sample of 149 adults with a confirmed diagnosis of ADHD participated in…

FACTOR STRUCTURE OF DSM-IV SYMPTOMS IN ADULTS

EPA Science Inventory

Objective: In up to 50% of clinic-referred samples of children, ADHD symptoms persist into adulthood,1-3 with the prevalence of adult ADHD currently estimated at 4.4%4. Similar to the pervasive impairments experienced by children with ADHD, adults with ADHD are less likely to com...

Sex Education for Deaf-Blind Youths and Adults.

ERIC Educational Resources Information Center

Ingraham, Cynthia L.; Vernon, McCay; Clemente, Brenda; Olney, Linda

2000-01-01

This article describes a model sex education program developed for youths and adults who are deafblind by the Helen Keller National Center for Deaf-Blind Youths and Adults. In addition, it also discusses major related issues and presents general recommendations and a resource for further information. (Contains 11 references.) (Author/CR)

Clinical chemistry reference intervals of healthy adult populations in Gojjam Zones of Amhara National Regional State, Northwest Ethiopia.

PubMed

Mekonnen, Zewdie; Amuamuta, Asmare; Mulu, Wondemagegn; Yimer, Mulat; Zenebe, Yohannes; Adem, Yesuf; Abera, Bayeh; Gebeyehu, Wondemu; Gebregziabher, Yakob

2017-01-01

Reference interval is crucial for disease screening, diagnosis, monitoring, progression and treatment efficacy. Due to lack of locally derived reference values for the parameters, clinicians use reference intervals derived from western population. But, studies conducted in different African countries have indicated differences between locally and western derived reference values. Different studies also indicated considerable variation in clinical chemistry reference intervals by several variables such as age, sex, geographical location, environment, lifestyle and genetic variation. This study aimed to determine the reference intervals of common clinical chemistry parameters of the community of Gojjam Zones, Northwest Ethiopia. Population based cross-sectional study was conducted from November 2015 to December 2016 in healthy adult populations of Gojjam zone. Data such as, medical history, physical examination and socio-demographic data were collected. In addition, laboratory investigations were undertaken to screen the population. Clinical chemistry parameters were measured using Mindray BS 200 clinical chemistry autoanalyzer as per the manufacturer's instructions. Descriptive statistics was used to calculate mean, median and 95th percentiles. Independent sample T-test and one way ANOVA were used to see association between variables. After careful screening of a total of 799 apparently healthy adults who were consented for this study, complete data from 446 (224 females and 222 males) were included for the analysis. The mean age of both the study participants was 28.8 years. Males had high (P<0.05) mean and 2.5th-97.5th percentile ranges of ALT, AST, ALP, creatinine and direct bilirubin. The reference intervals of amylase, LDH, total protein and total bilirubin were not significantly different between the two sex groups (P>0.05). Mean, median, 95% percentile values of AST, ALP, amylase, LDH, creatinine, total protein, total bilirubin, and direct bilirubin across all age groups of participants were similar (P>0.05). But, there was a significant difference in the value of ALT (P<0.05). The reference intervals of ALT, total protein and creatinine were significantly (P<0.05) high in people having monthly income >1500 ETB compared to those with low monthly income. Significant (P<0.05) higher values of the ALT, ALP and total protein were observed in people living in high land compared to low land residences. The study showed that some of the common clinical chemistry parameters reference intervals of healthy adults in Gojjam zones were higher than the reference intervals generated from developed countries. Therefore, strict adherence to the reference values generated in developed countries could lead to inappropriate diagnosis and treatment of patients. There was also variation of reference interval values based on climate, gender, age, monthly income and geographical locations. Therefore, further study is required to establish reference intervals for Ethiopian population.

The Development of NP Selection in School-Age Children: Reference and Spanish Subject Pronouns

ERIC Educational Resources Information Center

Shin, Naomi Lapidus; Cairns, Helen Smith

2012-01-01

To investigate the development of the NP selection process, preferences for overt or null Spanish subject pronouns were elicited from 139 children (5;09 to 15;08) and 30 adults in Mexico. Participants were told stories in which consecutive grammatical subjects shared the same referent (same-reference), or did not (switch-reference). In the…

Modeling Cross-Situational Word-Referent Learning: Prior Questions

ERIC Educational Resources Information Center

Yu, Chen; Smith, Linda B.

2012-01-01

Both adults and young children possess powerful statistical computation capabilities--they can infer the referent of a word from highly ambiguous contexts involving many words and many referents by aggregating cross-situational statistical information across contexts. This ability has been explained by models of hypothesis testing and by models of…

The Stayhealthy bioelectrical impedance analyzer predicts body fat in children and adults.

PubMed

Erceg, David N; Dieli-Conwright, Christina M; Rossuello, Amerigo E; Jensky, Nicole E; Sun, Stephanie; Schroeder, E Todd

2010-05-01

Bioelectrical impedance analysis (BIA) is a time-efficient and cost-effective method for estimating body composition. We hypothesized that there would be no significant difference between the Stayhealthy BC1 BIA and the selected reference methods when determining body composition. Thus, the purpose of the present study was to determine the validity of estimating percent body fat (%BF) using the Stayhealthy BIA with its most recently updated algorithms compared to the reference methods of dual-energy x-ray absorptiometry for adults and hydrostatic weighing for children. We measured %BF in 245 adults aged 18 to 80 years and 115 children aged 10 to 17 years. Body fat by BIA was determined using a single 50 kHz frequency handheld impedance device and proprietary software. Agreement between BIA and reference methods was assessed by Bland and Altman plots. Bland and Altman analysis for men, women, and children revealed good agreement between the reference methods and BIA. There was no significant difference by t tests between mean %BF by BIA for men, women, or children when compared to the respective reference method. Significant correlation values between BIA, and reference methods for all men, women, and children were 0.85, 0.88, and 0.79, respectively. Reliability (test-retest) was assessed by intraclass correlation coefficient and coefficient of variation. Intraclass correlation coefficient values were greater than 0.99 (P < .001) for men, women, and children with coefficient of variation values 3.3%, 1.8%, and 1.7%, respectively. The Stayhealthy BIA device demonstrated good agreement between reference methods using Bland and Altman analyses. Copyright 2010 Elsevier Inc. All rights reserved.

A survey of adult referrals to specialist attention-deficit/hyperactivity disorder clinics in Canada

PubMed Central

Klassen, Larry J; Blackwood, C Matthew; Reaume, Christopher J; Schaffer, Samuel; Burns, James G

2018-01-01

Background Canadian guidelines encourage family physicians to diagnose/manage adults with uncomplicated attention-deficit/hyperactivity disorder (ADHD); specialist referral is recommended only for complex cases. This retrospective case review investigated adults referred to Canadian ADHD clinics. Methods Adult ADHD specialists reviewed referral letters/charts of patients (aged ≥18 years and no family history/known/expressed childhood ADHD) from family physicians/psychiatrists over 2 years. Results Data on 515 referrals (mean age 33 years, 60% males) were collected (December 2014 to September 2015); 472/515 (92%) were made by family physicians. No psychiatric comorbid symptoms were noted in 344/515 (67%) referrals. ADHD was confirmed by a specialist in 483/515 (94%) cases, whether comorbid symptoms were noted at referral (155/171 [91%]) or not (328/344 [95%]). ADHD was reported to impact “work” (251/317 [79%]), “school” (121/166 [73%]), “social/friends” (260/483 [54%]), and “spouse/family” (231/483 [48%]). Overall, 335/483 (69%) patients had more than or equal to one comorbid symptom (diagnosed by referring physician or specialist). Stimulant monotherapy was recommended for 383/483 (79%) patients, non-stimulant monotherapy for 41/483 (8%) patients, and stimulant plus non-stimulant monotherapy for 39/483 (8%) patients. Almost half of patients were returned for referring physician’s follow-up, either before treatment initiation (102/483 [21%]) or after treatment stabilization (99/483 [20%]). Follow-up was by a specialist for 282/483 (58%) patients. Conclusion ADHD diagnosis was specialist confirmed in most cases. Although most referrals (67%) noted no psychiatric comorbid symptoms, 69% of patients had ≥1 such symptom (diagnosed by a referring physician or specialist), so comorbid symptoms although not always noted at referral, may have contributed to the decision to refer. ADHD has a wide-ranging impact on patients’ daily lives. It is possible that greater confidence of family physicians to diagnose and treat adult ADHD could help to meet patients’ needs. PMID:29317844

In Defense of Offering Educational Programs for Older Adults.

ERIC Educational Resources Information Center

Mehrotra, Chandra M.

2003-01-01

Older adults participate in education to fulfil coping, expressive, contributive, influence, and transcendence needs. Learning can promote sustained mental functioning and increase self-efficacy and social support. (Contains 15 references.) (SK)

Serum TSH reference interval in healthy Finnish adults using the Abbott Architect 2000i Analyzer.

PubMed

Schalin-Jäntti, Camilla; Tanner, Pirjo; Välimäki, Matti J; Hämäläinen, Esa

2011-07-01

Current serum TSH reference intervals have been criticized as they were established from unselected background populations. A special concern is that the upper limit, which defines subclinical hypothyroidism, is too high. The objective was to redefine the TSH reference interval in the adult Finnish population. The current reference interval for the widely used Abbott Architect method in Finland is 0.4-4.0 mU/L. Serum TSH and free T4 concentrations were derived from 606 healthy, non-pregnant, 18-91-year-old Finns from the Nordic Reference Interval Project (NORIP) and the possible effects of age, sex and thyroid peroxidase antibody (TPOAb) status were evaluated. After excluding TPOAb-positive subjects and outliers, a reference population of 511 subjects was obtained. In the reference population, no statistically significant gender- or age-specific differences in mean TSH (1.55 ± 3.30 mU/L) or TSH reference intervals were observed. The new reference interval was 0.5-3.6 mU/L (2.5th-97.5th percentiles). The current upper TSH reference limit is 10% too high. A TSH > 3.6 mU/L, confirmed with a repeat TSH sampling, may indicate subclinical hypothyroidism. Differences in ethnicity, regional iodine-intake and analytical methods underline the need for redefining the TSH reference interval in central laboratories in different countries.

Can You Imagine? The Effect of Mental Practice on the Acquisition and Retention of a Motor Skill as a Function of Age.

ERIC Educational Resources Information Center

Jarus, Tal; Ratzon, Navah Z.

2000-01-01

A study investigated the effect of age on mental practice in 30 children, 30 adults, and 30 older adults randomly participating in physical and mental-physical practice. Mental practice benefitted children and older adults in coordination tasks. Older adults especially benefitted from mental practice in retention tasks. (Contains 58 references.)…

Adult Education Development and the NAEP. Report of the All India Adult Education Conference (32nd, Amritsar, India, October 7-9, 1979). Series No. 134.

ERIC Educational Resources Information Center

Indian Adult Education Association, New Delhi.

This publication contains the proceedings of a conference held to discuss adult education and the National Adult Education Programme (NAEP) in India. Four major addresses are included in the booklet, along with references to other speeches, group discussion reports, resolutions, and recommendations. Inaugurating the conference, Shri J.J. Kidwai…

Reference ranges of handgrip strength from 125,462 healthy adults in 21 countries: a prospective urban rural epidemiologic (PURE) study.

PubMed

Leong, Darryl P; Teo, Koon K; Rangarajan, Sumathy; Kutty, V Raman; Lanas, Fernando; Hui, Chen; Quanyong, Xiang; Zhenzhen, Qian; Jinhua, Tang; Noorhassim, Ismail; AlHabib, Khalid F; Moss, Sarah J; Rosengren, Annika; Akalin, Ayse Arzu; Rahman, Omar; Chifamba, Jephat; Orlandini, Andrés; Kumar, Rajesh; Yeates, Karen; Gupta, Rajeev; Yusufali, Afzalhussein; Dans, Antonio; Avezum, Álvaro; Lopez-Jaramillo, Patricio; Poirier, Paul; Heidari, Hosein; Zatonska, Katarzyna; Iqbal, Romaina; Khatib, Rasha; Yusuf, Salim

2016-12-01

The measurement of handgrip strength (HGS) has prognostic value with respect to all-cause mortality, cardiovascular mortality and cardiovascular disease, and is an important part of the evaluation of frailty. Published reference ranges for HGS are mostly derived from Caucasian populations in high-income countries. There is a paucity of information on normative HGS values in non-Caucasian populations from low- or middle-income countries. The objective of this study was to develop reference HGS ranges for healthy adults from a broad range of ethnicities and socioeconomically diverse geographic regions. HGS was measured using a Jamar dynamometer in 125,462 healthy adults aged 35-70 years from 21 countries in the Prospective Urban Rural Epidemiology (PURE) study. HGS values differed among individuals from different geographic regions. HGS values were highest among those from Europe/North America, lowest among those from South Asia, South East Asia and Africa, and intermediate among those from China, South America, and the Middle East. Reference ranges stratified by geographic region, age, and sex are presented. These ranges varied from a median (25 th -75 th percentile) 50 kg (43-56 kg) in men <40 years from Europe/North America to 18 kg (14-20 kg) in women >60 years from South East Asia. Reference ranges by ethnicity and body-mass index are also reported. Individual HGS measurements should be interpreted using region/ethnic-specific reference ranges.

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

PubMed

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

2014-01-01

The National Health and Nutrition Examination Survey (NHANES 1999-2004) includes adult and pediatric comparisons for total body bone and body composition results. Because dual-energy x-ray absorptiometry (DXA) measurements from different manufacturers are not standardized, NHANES reference values currently are applicable only to a single make and model of Hologic DXA system. The purpose of this study was to derive body composition reference curves for GE Healthcare Lunar DXA systems. Published values from the NHANES 1999-2004 survey were acquired from the Centers for Disease Control and Prevention website. Using previously reported cross-calibration equations between Hologic and GE-Lunar, we converted the total body and regional bone and soft-tissue measurements from NHANES 1999-2004 to GE-Lunar values. The LMS (LmsChartMaker Pro Version 3.5) curve fitting method was used to generate GE-Lunar reference curves. Separate curves were generated for each sex and ethnicity. The reference curves were also divided into pediatric (≤20 years old) and adult (>20 years old) groups. Adult reference curves were derived as a function of age. Additional relationships of pediatric DXA values were derived as a function of height, lean mass, and bone area. Robustness was tested between Hologic and GE-Lunar Z-score values. The NHANES 1999-2004 survey included a sample of 20,672 participants' (9630 female) DXA scans. A total of 8056 participants were younger than 20 yr and were included in the pediatric reference data set. Participants enrolled in the study who weighed more than 136 kg (over scanner table limit) were excluded. The average Z-scores comparing the new GE-Lunar reference curves are close to zero, and the standard deviation of the Z-scores are close to one for all variables. As expected, all measurements on the GE-Lunar reference curves for participants younger than 20 yr increase monotonically with age. In the adult population, most of the curves are constant at younger age and drop moderately as age increases. We have presented NHANES reference curves applicable to DXA whole-body scans acquired on GE Healthcare Lunar systems by age, sex and ethnicity. Users of GE Healthcare GE-Lunar DXA systems can now benefit from the large body composition reference data set collected in the NHANES 1999-2004 study. Copyright © 2014 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

Influence of verbal and nonverbal references to print on preschoolers' visual attention to print during storybook reading.

PubMed

Justice, Laura M; Pullen, Paige C; Pence, Khara

2008-05-01

How much do preschool children look at print within storybooks when adults read to them? This study sought to answer this question as well as to examine the effects of adult verbal and nonverbal references to print on children's visual attention to print during storybook reading. Forty-four preschool-aged children participated in this study designed to determine the amount of visual attention children paid to print in 4 planned variations of storybook reading. Children's visual attention to print was examined when adults commented and questioned about print (verbal print condition) or pointed to and tracked the print (nonverbal print condition), relative to 2 comparison conditions (verbatim reading and verbal picture conditions). Results showed that children rarely look at print, with about 5%-6% of their fixations allocated to print in verbatim and verbal picture reading conditions. However, preschoolers' visual attention to print increases significantly when adults verbally and nonverbally reference print; both reading styles exerted similar effects. The authors conclude that explicit referencing of print is 1 way to increase young children's contacts with print during shared storybook reading. (PsycINFO Database Record (c) 2008 APA, all rights reserved).

International Dictionary of Adult and Continuing Education. Revised Edition.

ERIC Educational Resources Information Center

Jarvis, Peter

This dictionary defines approximately 3,500 terms related to adult, continuing, higher, and lifelong learning. It provides detailed references to the main historical and contemporary figures, organizations, and concepts involved in adult and further education around the world with a distinct focus on the core issues in this rapidly changing field.…

Does Sex Influence the Diagnostic Evaluation of Autism Spectrum Disorder in Adults?

ERIC Educational Resources Information Center

Wilson, C. Ellie; Murphy, Clodagh M.; McAlonan, Grainne; Robertson, Dene M.; Spain, Debbie; Hayward, Hannah; Woodhouse, Emma; Deeley, P. Quinton; Gillan, Nicola; Ohlsen, J. Chris; Zinkstok, Janneke; Stoencheva, Vladimira; Faulkner, Jessica; Yildiran, Hatice; Bell, Vaughan; Hammond, Neil; Craig, Michael C.; Murphy, Declan G. M.

2016-01-01

It is unknown whether sex influences the diagnostic evaluation of autism spectrum disorder, or whether male and female adults within the spectrum have different symptom profiles. This study reports sex differences in clinical outcomes for 1,244 adults (935 males and 309 females) referred for autism spectrum disorder assessment. Significantly, more…

46 CFR 160.002-1 - Incorporation by reference.

Code of Federal Regulations, 2014 CFR

2014-10-01

.... General Purpose, Natural or in Colors. (2) Federal Specification: L-P-375—Plastic Film, Flexible, Vinyl...: (Sheet 1) Cutting Pattern and General Arrangement (adult). (Sheet 1A) Alternate stitching of tapes and webbing (adult and child). (Sheet 2) Pad Detail (adult). Dwg. No. F-49-6-5: (Sheet 1) Cutting Pattern and...

46 CFR 160.002-1 - Incorporation by reference.

Code of Federal Regulations, 2013 CFR

2013-10-01

.... General Purpose, Natural or in Colors. (2) Federal Specification: L-P-375—Plastic Film, Flexible, Vinyl...: (Sheet 1) Cutting Pattern and General Arrangement (adult). (Sheet 1A) Alternate stitching of tapes and webbing (adult and child). (Sheet 2) Pad Detail (adult). Dwg. No. F-49-6-5: (Sheet 1) Cutting Pattern and...

46 CFR 160.002-1 - Incorporation by reference.

Code of Federal Regulations, 2010 CFR

2010-10-01

.... General Purpose, Natural or in Colors. (2) Federal Specification: L-P-375—Plastic Film, Flexible, Vinyl...: (Sheet 1) Cutting Pattern and General Arrangement (adult). (Sheet 1A) Alternate stitching of tapes and webbing (adult and child). (Sheet 2) Pad Detail (adult). Dwg. No. F-49-6-5: (Sheet 1) Cutting Pattern and...

46 CFR 160.002-1 - Incorporation by reference.

Code of Federal Regulations, 2011 CFR

2011-10-01

.... General Purpose, Natural or in Colors. (2) Federal Specification: L-P-375—Plastic Film, Flexible, Vinyl...: (Sheet 1) Cutting Pattern and General Arrangement (adult). (Sheet 1A) Alternate stitching of tapes and webbing (adult and child). (Sheet 2) Pad Detail (adult). Dwg. No. F-49-6-5: (Sheet 1) Cutting Pattern and...

46 CFR 160.002-1 - Incorporation by reference.

Code of Federal Regulations, 2012 CFR

2012-10-01

.... General Purpose, Natural or in Colors. (2) Federal Specification: L-P-375—Plastic Film, Flexible, Vinyl...: (Sheet 1) Cutting Pattern and General Arrangement (adult). (Sheet 1A) Alternate stitching of tapes and webbing (adult and child). (Sheet 2) Pad Detail (adult). Dwg. No. F-49-6-5: (Sheet 1) Cutting Pattern and...

A Descriptive Investigation of Dysphagia in Adults with Intellectual Disabilities

ERIC Educational Resources Information Center

Chadwick, Darren D.; Jolliffe, J.

2009-01-01

Background: Dysphagia has rarely been investigated in adults with intellectual disabilities (ID) despite being a serious condition affecting health and quality of life. Method: This study collected information about 101 adults with ID, living in community settings, referred for an assessment of their eating and drinking. Ninety-nine people were…

The Making of Entrepreneurial Subjectivity in Adult Education

ERIC Educational Resources Information Center

Siivonen, Päivi; Brunila, Kristiina

2014-01-01

This article focuses on the idea of entrepreneurial subjectivity and the ways in which it is shaped by the entrepreneurial discourse in adult education. As a result, we argue that educational practices related to adults form a particular kind of ideal subjectivity that we refer to as entrepreneurial. In order to understand how this entrepreneurial…

Adult Continuing Education and Human Resource Development: Present Competitors, Potential Partners

ERIC Educational Resources Information Center

Smith, Douglas H.

2013-01-01

"Author's Note": In May 1989, this article was published in "Livelong Learning," the monthly practitioner journal of the American Association for Adult and Continuing Education (Vol. 12, No. 7, pp. 13-17). Now viewed as a period reference article, it presents the relationship of adult and continuing education (ACE) and…

Ties that Bind: Cultural Referent Groups and Coping Strategies of Adult Women as Learners

ERIC Educational Resources Information Center

Nanton, Carmela R.

2009-01-01

This chapter examines the cultural influences and applications of women's social capital networks on women's knowledge construction, community development, and autonomy within their cultures and the adult learning context.

Advisory Committee on Immunization Practices recommended immunization schedule for adults aged 19 years or older - United States, 2014.

PubMed

Bridges, Carolyn B; Coyne-Beasley, Tamera

2014-02-07

Vaccines are recommended for adults on the basis of their age, prior vaccinations, health conditions, lifestyle, occupation, and travel. Reasons for current low levels of vaccination coverage for adult vaccines are multifactorial and include limited awareness among the public about vaccines for adults and gaps in incorporation of regular assessments of vaccine needs and vaccination into routine medical care. Updated standards for immunization of adults were approved by the National Vaccine Advisory Committee (NVAC) in September 2013. These standards acknowledge the current low levels of vaccination coverage among adults and the role that all health-care providers, including those who do not offer all recommended adult vaccines in their practices, have in ensuring that their patients are up-to-date on recommended vaccines. NVAC recommends that providers assess vaccination needs for their patients at each visit, recommend needed vaccines, and then, ideally, offer the vaccine or, if the provider does not stock the needed vaccines, refer the patient to a provider who does vaccinate. Vaccinating providers should also ensure that patients and their referring health-care providers have documentation of the vaccination.

Self-reported knee pain and disability among healthy individuals: reference data and factors associated with the Knee injury and Osteoarthritis Outcome Score (KOOS) and KOOS-Child.

PubMed

Baldwin, J N; McKay, M J; Simic, M; Hiller, C E; Moloney, N; Nightingale, E J; Burns, J

2017-08-01

To develop normative reference data for the Knee injury and Osteoarthritis Outcome Score (KOOS) and KOOS-Child, as well as investigate socio-demographic, psychological and physical factors associated with knee pain and disability among healthy adults. The KOOS or KOOS-Child (each containing five subscales) was administered to participants aged 8-101 years within the 1000 Norms Project, an observational study of 1000 self-reported healthy individuals. Self-efficacy, physical activity, body mass index (BMI), lower limb alignment, knee frontal plane projection angle (FPPA), knee range of motion (ROM), knee and hip strength, six-minute walk, 30-second chair stand and timed up and down stairs tests were collected. KOOS data were dichotomised using established cut-off scores and logistic regression analyses were conducted for each subscale. Socio-demographic characteristics were similar to the Australian population. Normative reference data were generated for children (8-17 years) and adults (18-101 years). Female adults were up to twice as likely to report knee pain, symptoms and sport/recreation (Sport/Rec) limitations compared to males (P < .05). Older age, lower self-efficacy, greater BMI, varus lower limb alignment, lower knee flexion ROM and lower hip external rotation (ER) strength were independently associated with knee pain and disability among adults. Age- and gender-stratified reference data for the KOOS and KOOS-Child have been developed to guide interpretation of results in practice and research for individuals with knee disorders. Psychological and physical factors are linked with self-reported knee pain/disability among adults, and longitudinal studies to investigate causation are required. Copyright © 2017 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Young Children's Intonational Marking of New, Given and Contrastive Referents

ERIC Educational Resources Information Center

Grünloh, Thomas; Lieven, Elena; Tomasello, Michael

2015-01-01

In the current study we investigate whether 2- and 3-year-old German children use intonation productively to mark the informational status of referents. Using a story-telling task, we compared children's and adults' intonational realization via pitch accent (H*, L* and de-accentuation) of New, Given, and Contrastive referents. Both children and…

THE BACON not the bacon: How children and adults understand accented and unaccented noun phrases

PubMed Central

Arnold, Jennifer E.

2008-01-01

Two eye-tracking experiments examine whether adults and 4 and 5 year old children use the presence or absence of accenting to guide their interpretation of noun phrases (e.g., the bacon) with respect to the discourse context. Unaccented nouns tend to refer to contextually accessible referents, while accented variants tend to be used for less accessible entities. Experiment 1 confirms that accenting is informative for adults, who show a bias toward previously-mentioned objects beginning 300 msec after the onset of unaccented nouns and pronouns. But contrary to findings in the literature, accented words produced no observable bias. In Experiment 2, 4 and 5 year olds were also biased toward previously-mentioned objects with unaccented nouns and pronouns. This builds on findings of limits on children’s on-line reference comprehension (Arnold, Brown-Schmidt, & Trueswell, in press), showing that children’s interpretation of unaccented nouns and pronouns is constrained in contexts with one single highly accessible object. PMID:18358460

IQ, handedness, and pedophilia in adult male patients stratified by referral source.

PubMed

Blanchard, Ray; Kolla, Nathan J; Cantor, James M; Klassen, Philip E; Dickey, Robert; Kuban, Michael E; Blak, Thomas

2007-09-01

This study investigated whether the previously observed association of pedophilia with lower IQs is an artifact of heterogeneity in referral source. The subjects were 832 adult male patients referred to a specialty clinic for evaluation of their sexual behavior. The patients' erotic preferences for prepubescent, pubescent, or adult partners were assessed with phallometric testing. Full scale IQ was estimated using six subtests from the WAIS-R. The results showed that the relations between pedophilia and lower IQ, lesser education, and increased rates of non-right-handedness were the same in homogeneous groups referred by lawyers or parole and probation officers as they were in a heterogeneous group referred by a miscellany of other sources. Those results, along with secondary analyses in the study, supported the conclusion that the relation between pedophilia and cognitive function is genuine and not artifactual. The findings were interpreted as evidence for the hypothesis that neurodevelopmental perturbations increase the risk of pedophilia in males.

A developmental analysis of elementary school-aged children's concepts of pride and embarrassment.

PubMed

Seidner, L B; Stipek, D J; Feshbach, N D

1988-04-01

Developmental changes in conditions engendering pride and embarrassment were explored. Subjects included 41 adults and 189 5-, 7-, 9-, and 11-year-old children from diverse ethnic backgrounds. Subjects were asked to report events that had made them feel proud, embarrassed, happy, and sad. Content analyses of responses concerning pride and embarrassment indicated that references to noncontingent, uncontrollable events decreased with age, but most 5-year-olds understood that feelings of pride and, to a lesser extent, embarrassment result primarily from outcomes controlled by and contingent on one's own behavior or characteristics. Responses of children in all 4 age groups and adults suggest that an audience is important for both pride and embarrassment, but particularly for embarrassment. An audience and external reinforcement were more important in children's than in adults' reports of pride. Developmental change was found in the standards used to evaluate emotional experiences; references to social comparison increased with age and references to mastery decreased.

Ageing and the group-reference effect in memory.

PubMed

Lee, Hyeon-Nyeon; Rosa, Nicole M; Gutchess, Angela H

2016-07-01

The present study examines age differences in the memory benefits from group-referncing. While prior work establishes that the memory performance of younger and older adults similarly benefits from relating information to the self, this study assessed whether those benefits extend to referencing a meaningful group membership. Young and older adult participants encoded trait words by judging whether each word describes themselves, describes their group membership (selected for each age group), or is familiar. After a retention interval, participants completed a surprise recognition memory test. The results indicate that group-referencing increased recognition memory performance compared to the familiarity judgements for both young and older groups. However, the group-reference benefit is limited, emerging as smaller than the benefit from self-referencing. These results challenge previous findings of equivalent benefits for group-referencing and self-referencing, suggesting that such effects may not prevail under all conditions, including for older adults. The findings also highlight the need to examine the mechanisms of group-referencing that can lead to variability in the group-reference effect.

Transfer of aged Pu to cattle grazing on a contaminated environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gilbert, R.O.; Engel, D.W.; Smith, D.D.

1988-03-01

Estimates are obtained of the fraction of ingested or inhaled 239+240Pu transferred to blood and tissues of a reproducing herd of beef cattle, individuals of which grazed within fenced enclosures for up to 1064 d under natural conditions with no supplemental feeding at an arid site contaminated 16 y previously with Pu oxide. The estimated (geometric mean (GM)) fraction of Pu transferred from the gastrointestinal tract to blood serum was about 5 x 10(-6) (geometric standard error (GSE) = 1.4) with an approximate upper bound of about 2 x 10(-5). These results are in reasonable agreement with the value ofmore » 1 x 10(-5) recommended for human radiation protection purposes by the International Commission on Radiological Protection (ICRP) for insoluble Pu oxides that are free of very small particles. Also, results from a laboratory study by Stanley (St75), in which large doses of /sup 238/Pu were orally administered daily to dairy cattle for 19 consecutive days, suggest that aged 239+240Pu at this arid grazing site may not be more biologically available to blood serum than fresh 239+240Pu oxide. The estimated fractions of 239+240Pu transferred from blood serum to tissues of adult grazing cattle were: femur (3.2 X 10(-2), 1.8; GM, GSE), vertebra (1.4 X 10(-1), 1.6), liver (2.3 X 10(-1), 2.0), muscle (1.3 X 10(-1), 1.9), female gonads (7.9 X 10(-5), 1.5), and kidney (1.4 X 10(-3), 1.7). The blood-to-tissue fractional transfers for cattle initially exposed in utero were greater than those exposed only as adults by a factor of about 4 for femur (statistically significant) and of about 2 for other tissues (not significant). The estimated (GM) fraction of inhaled Pu initially deposited in the pulmonary lung was 0.34 (GSE = 1.3) for adults and 0.15 (GSE = 1.3) for cattle initially exposed in utero (a statistically significant difference).« less

Water and tissue equivalence properties of biological materials for photons, electrons, protons and alpha particles in the energy region 10 keV-1 GeV: a comparative study.

PubMed

Kurudirek, Murat

2016-09-01

To compare some biological materials in respect to the water and tissue equivalence properties for photon, electron, proton and alpha particle interactions as means of the effective atomic number (Zeff) and electron density (Ne). A Z-wise interpolation procedure has been adopted for calculation of Zeff using the mass attenuation coefficients for photons and the mass stopping powers for charged particles. At relatively low energies (100 keV-3 MeV), Zeff and Ne for photons and electrons were found to be constant while they vary much more for protons and alpha particles. In contrast, Zeff and Ne for protons and alpha particles were found to be constant after 3 MeV whereas for photons and electrons they were found to increase with the increasing energy. Also, muscle eq. liquid (with sucrose) have Zeff and Ne values close to the Muscle Skeletal (ICRP) and Muscle Striated (ICRU) within low relative differences below 9%. Muscle eq. liquid (without sucrose) have Zeff and Ne values close to the Muscle Skeletal (ICRP) and Muscle Striated (ICRU) with difference below 10%. The reported data should be useful in determining best water as well as tissue equivalent materials for photon, electron, proton and alpha particle interactions.

The effective dose result of 18F-FDG PET-CT paediatric patients

NASA Astrophysics Data System (ADS)

Hussin, D.; Said, M. A.; Ali, N. S.; Tajuddin, A. A.; Zainon, R.

2017-05-01

Paediatric patient received high exposure from both CT and PET examination. Automatic Exposure Control (AEC) is important in CT dose reduction. This study aimed to compare the effective dose obtained from PET-CT scanner with and without the use of AEC function. In this study, 68 patients underwent PET-CT examination without the use of AEC function, while 25 patients used the AEC function during the examination. Patients involved in this study were between 2 to 15 years old with varies of malignancies and epilepsy diseases. The effective dose obtained from PET and CT examinations was calculated based on recommendation from International Commission on Radiological Protection (ICRP) Publication 106 and ICRP publication 102. The outcome of this study shows that the radiation dose was reduced up to 20% with the use of AEC function. The mean average of effective dose result obtained from PET and CT examinations without the use of AEC and AEC function were found to be as 6.67 mSv, 6.77 mSv, 6.03mSv and 4.96 mSv respectively. Where total effective dose result of PET-CT with non-AEC and AEC were found to be 13.44 mSv and 10.99 mSv respectively. Conclusion of this study is, the installation of AEC function in PET-CT machine does play important role in CT dose reduction especially for paediatric patient.

Measurement of dose equivalent distribution on-board commercial jet aircraft.

PubMed

Kubančák, J; Ambrožová, I; Ploc, O; Pachnerová Brabcová, K; Štěpán, V; Uchihori, Y

2014-12-01

The annual effective doses of aircrew members often exceed the limit of 1 mSv for the public due to the increased level of cosmic radiation at the flight altitudes, and thus, it is recommended to monitor them [International Commission on Radiation Protection. 1990 Recommendations of the International Commission on Radiological Protection. ICRP Publication 60. Ann. ICRP 21: (1-3), (1991)]. According to the Monte Carlo simulations [Battistoni, G., Ferrari, A., Pelliccioni, M. and Villari, R. Evaluation of the doses to aircrew members taking into consideration the aircraft structures. Adv. Space Res. 36: , 1645-1652 (2005) and Ferrari, A., Pelliccioni, M. and Villari, R. Evaluation of the influence of aircraft shielding on the aircrew exposure through an aircraft mathematical model. Radiat. Prot. Dosim. 108: (2), 91-105 (2004)], the ambient dose equivalent rate Ḣ*(10) depends on the location in the aircraft. The aim of this article is to experimentally evaluate Ḣ*(10) on-board selected types of aircraft. The authors found that Ḣ*(10) values are higher in the front and the back of the cabin and lesser in the middle of the cabin. Moreover, total dosimetry characteristics obtained in this way are in a reasonable agreement with other data, in particular with the above-mentioned simulations. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The threshold vs LNT showdown: Dose rate findings exposed flaws in the LNT model part 1. The Russell-Muller debate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calabrese, Edward J., E-mail: edwardc@schoolph.uma

This paper assesses the discovery of the dose-rate effect in radiation genetics and how it challenged fundamental tenets of the linear non-threshold (LNT) dose response model, including the assumptions that all mutational damage is cumulative and irreversible and that the dose-response is linear at low doses. Newly uncovered historical information also describes how a key 1964 report by the International Commission for Radiological Protection (ICRP) addressed the effects of dose rate in the assessment of genetic risk. This unique story involves assessments by two leading radiation geneticists, Hermann J. Muller and William L. Russell, who independently argued that the report'smore » Genetic Summary Section on dose rate was incorrect while simultaneously offering vastly different views as to what the report's summary should have contained. This paper reveals occurrences of scientific disagreements, how conflicts were resolved, which view(s) prevailed and why. During this process the Nobel Laureate, Muller, provided incorrect information to the ICRP in what appears to have been an attempt to manipulate the decision-making process and to prevent the dose-rate concept from being adopted into risk assessment practices. - Highlights: • The discovery of radiation dose rate challenged the scientific basis of LNT. • Radiation dose rate occurred in males and females. • The dose rate concept supported a threshold dose-response for radiation.« less

Transfer of environmental plutonium and americium across the human gut.

PubMed

Hunt, G J; Leonard, D R; Lovett, M B

1986-08-01

Data on gut transfer factors for environmental forms of radionuclides are essential for estimates of public radiation exposures following ingestion, and thus in decisions on controlling waste discharges. Dose estimates for transuranic nuclides are particularly sensitive to uncertainties stemming from gut transfer data being related to non-environmental forms and/or derived from animal experiments. We have measured human gut transfer factors for plutonium and americium in two experiments using marine foods obtained near Sellafield, Cumbria. Firstly, the urine of volunteer members of the critical group of shellfish consumers was analysed for transuranics and the results related to their consumption rates. Secondly, remotely-based volunteers ate single quantities of shellfish obtained near Sellafield, and their urine was analysed. An overall result for the gut transfer factor for environmental plutonium of 0.8 X 10(-4) indicates no need to increase the value of 1 X 10(-4), currently used by the International Commission on Radiological Protection (ICRP) for soluble forms. Results for americium show that the ICRP value of 5 X 10(-4) is maximising, and that a value of 1 X 10(-4) would be supportable. The results from the study of critical group members provide confidence in our habits survey techniques and reassurance that there are no significant pathways for intake of transuranics by these people that have not been recognised.

Electrocardiogram reference intervals for clinically normal wild-born chimpanzees (Pan troglodytes).

PubMed

Atencia, Rebeca; Revuelta, Luis; Somauroo, John D; Shave, Robert E

2015-08-01

To generate reference intervals for ECG variables in clinically normal chimpanzees (Pan troglodytes). 100 clinically normal (51 young [< 10 years old] and 49 adult [≥ 10 years old]) wild-born chimpanzees. Electrocardiograms collected between 2009 and 2013 at the Tchimpounga Chimpanzee Rehabilitation Centre were assessed to determine heart rate, PR interval, QRS duration, QT interval, QRS axis, P axis, and T axis. Electrocardiographic characteristics for left ventricular hypertrophy (LVH) and morphology of the ST segment, T wave, and QRS complex were identified. Reference intervals for young and old animals were calculated as mean ± 1.96•SD for normally distributed data and as 5th to 95th percentiles for data not normally distributed. Differences between age groups were assessed by use of unpaired Student t tests. RESULTS Reference intervals were generated for young and adult wild-born chimpanzees. Most animals had sinus rhythm with small or normal P wave morphology; 24 of 51 (47%) young chimpanzees and 30 of 49 (61%) adult chimpanzees had evidence of LVH as determined on the basis of criteria for humans. Cardiac disease has been implicated as the major cause of death in captive chimpanzees. Species-specific ECG reference intervals for chimpanzees may aid in the diagnosis and treatment of animals with, or at risk of developing, heart disease. Chimpanzees with ECG characteristics outside of these intervals should be considered for follow-up assessment and regular cardiac monitoring.

Reference Values for Human Posture Measurements Based on Computerized Photogrammetry: A Systematic Review.

PubMed

Macedo Ribeiro, Ana Freire; Bergmann, Anke; Lemos, Thiago; Pacheco, Antônio Guilherme; Mello Russo, Maitê; Santos de Oliveira, Laura Alice; de Carvalho Rodrigues, Erika

The main objective of this study was to review the literature to identify reference values for angles and distances of body segments related to upright posture in healthy adult women with the Postural Assessment Software (PAS/SAPO). Electronic databases (BVS, PubMed, SciELO and Scopus) were assessed using the following descriptors: evaluation, posture, photogrammetry, physical therapy, postural alignment, postural assessment, and physiotherapy. Studies that performed postural evaluation in healthy adult women with PAS/SAPO and were published in English, Portuguese and Spanish, between the years 2005 and 2014 were included. Four studies met the inclusion criteria. Data from the included studies were grouped to establish the statistical descriptors (mean, variance, and standard deviation) of the body angles and distances. A total of 29 variables were assessed (10 in the anterior views, 16 in the lateral right and left views, and 3 in the posterior views), and its respective mean and standard deviation were calculated. Reference values for the anterior and posterior views showed no symmetry between the right and left sides of the body in the frontal plane. There were also small differences in the calculated reference values for the lateral view. The proposed reference values for quantitative evaluation of the upright posture in healthy adult women estimated in the present study using PAS/SAPO could guide future studies and help clinical practice. Copyright © 2017. Published by Elsevier Inc.

Hematology and serum clinical chemistry reference intervals for free-ranging Scandinavian gray wolves (Canis lupus).

PubMed

Thoresen, Stein I; Arnemo, Jon M; Liberg, Olof

2009-06-01

Scandinavian free-ranging wolves (Canis lupus) are endangered, such that laboratory data to assess their health status is increasingly important. Although wolves have been studied for decades, most biological information comes from captive animals. The objective of the present study was to establish reference intervals for 30 clinical chemical and 8 hematologic analytes in Scandinavian free-ranging wolves. All wolves were tracked and chemically immobilized from a helicopter before examination and blood sampling in the winter of 7 consecutive years (1998-2004). Seventy-nine blood samples were collected from 57 gray wolves, including 24 juveniles (24 samples), 17 adult females (25 samples), and 16 adult males (30 samples). Whole blood and serum samples were stored at refrigeration temperature for 1-3 days before hematologic analyses and for 1-5 days before serum biochemical analyses. Reference intervals were calculated as 95% confidence intervals except for juveniles where the minimum and maximum values were used. Significant differences were observed between adult and juvenile wolves for RBC parameters, alkaline phosphatase and amylase activities, and total protein, albumin, gamma-globulins, cholesterol, creatinine, calcium, chloride, magnesium, phosphate, and sodium concentrations. Compared with published reference values for captive wolves, reference intervals for free-ranging wolves reflected exercise activity associated with capture (higher creatine kinase activity, higher glucose concentration), and differences in nutritional status (higher urea concentration).

National Survey of Adult and Pediatric Reference Intervals in Clinical Laboratories across Canada: A Report of the CSCC Working Group on Reference Interval Harmonization.

PubMed

Adeli, Khosrow; Higgins, Victoria; Seccombe, David; Collier, Christine P; Balion, Cynthia M; Cembrowski, George; Venner, Allison A; Shaw, Julie

2017-11-01

Reference intervals are widely used decision-making tools in laboratory medicine, serving as health-associated standards to interpret laboratory test results. Numerous studies have shown wide variation in reference intervals, even between laboratories using assays from the same manufacturer. Lack of consistency in either sample measurement or reference intervals across laboratories challenges the expectation of standardized patient care regardless of testing location. Here, we present data from a national survey conducted by the Canadian Society of Clinical Chemists (CSCC) Reference Interval Harmonization (hRI) Working Group that examines variation in laboratory reference sample measurements, as well as pediatric and adult reference intervals currently used in clinical practice across Canada. Data on reference intervals currently used by 37 laboratories were collected through a national survey to examine the variation in reference intervals for seven common laboratory tests. Additionally, 40 clinical laboratories participated in a baseline assessment by measuring six analytes in a reference sample. Of the seven analytes examined, alanine aminotransferase (ALT), alkaline phosphatase (ALP), and creatinine reference intervals were most variable. As expected, reference interval variation was more substantial in the pediatric population and varied between laboratories using the same instrumentation. Reference sample results differed between laboratories, particularly for ALT and free thyroxine (FT4). Reference interval variation was greater than test result variation for the majority of analytes. It is evident that there is a critical lack of harmonization in laboratory reference intervals, particularly for the pediatric population. Furthermore, the observed variation in reference intervals across instruments cannot be explained by the bias between the results obtained on instruments by different manufacturers. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Genetics Home Reference: adult polyglucosan body disease

MedlinePlus

... This Page Klein CJ, Boes CJ, Chapin JE, Lynch CD, Campeau NG, Dyck PJ, Dyck PJ. Adult polyglucosan body disease: case description of an expanding genetic and clinical syndrome. Muscle Nerve. 2004 Feb;29(2):323-8. ...

49 CFR 572.131 - General description.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Female Test Dummy, Alpha Version § 572.131 General description. (a) The Hybrid III fifth percentile adult... Small Adult Female Crash Test Dummy (HIII-5F, Alpha Version) (June 2002) (refer to § 572.130(a)(1)(ix...

49 CFR 572.131 - General description.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Female Test Dummy, Alpha Version § 572.131 General description. (a) The Hybrid III fifth percentile adult... Small Adult Female Crash Test Dummy (HIII-5F, Alpha Version) (June 2002) (refer to § 572.130(a)(1)(ix...

49 CFR 572.131 - General description.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Female Test Dummy, Alpha Version § 572.131 General description. (a) The Hybrid III fifth percentile adult... Small Adult Female Crash Test Dummy (HIII-5F, Alpha Version) (June 2002) (refer to § 572.130(a)(1)(ix...

Falls among Older Adults: Public Health Impact and Prevention Strategies.

ERIC Educational Resources Information Center

Stevens, Judy A.

2003-01-01

Provides an overview of the epidemiology of falls among older adults, describes current prevention strategies, and highlights key areas that need to be addressed, including risk assessments, exercise, and environmental changes. (Contains 50 references.) (JOW)

Activity Levels in Healthy Older Adults: Implications for Joint Arthroplasty

PubMed Central

Thorp, Laura E.; Orozco, Diego; Block, Joel A.; Sumner, Dale R.; Wimmer, Markus A.

2012-01-01

This work evaluated activity levels in a group of healthy older adults to establish a target activity level for adults of similar age after total joint arthroplasty (TJA). With the decreasing age of TJA patients, it is essential to have a reference for activity level in younger patients as activity level affects quality of life and implant design. 54 asymptomatic, healthy older adults with no clinical evidence of lower extremity OA participated. The main outcome measure, average daily step count, was measured using an accelerometer-based activity monitor. On average the group took 8813 ± 3611 steps per day, approximately 4000 more steps per day than has been previously reported in patients following total joint arthroplasty. The present work provides a reference for activity after joint arthroplasty which is relevant given the projected number of people under the age of 65 who will undergo joint arthroplasty in the coming years. PMID:23577274

Selection of Reliable Reference Genes for Gene Expression Studies of a Promising Oilseed Crop, Plukenetia volubilis, by Real-Time Quantitative PCR.

PubMed

Niu, Longjian; Tao, Yan-Bin; Chen, Mao-Sheng; Fu, Qiantang; Li, Chaoqiong; Dong, Yuling; Wang, Xiulan; He, Huiying; Xu, Zeng-Fu

2015-06-03

Real-time quantitative PCR (RT-qPCR) is a reliable and widely used method for gene expression analysis. The accuracy of the determination of a target gene expression level by RT-qPCR demands the use of appropriate reference genes to normalize the mRNA levels among different samples. However, suitable reference genes for RT-qPCR have not been identified in Sacha inchi (Plukenetia volubilis), a promising oilseed crop known for its polyunsaturated fatty acid (PUFA)-rich seeds. In this study, using RT-qPCR, twelve candidate reference genes were examined in seedlings and adult plants, during flower and seed development and for the entire growth cycle of Sacha inchi. Four statistical algorithms (delta cycle threshold (ΔCt), BestKeeper, geNorm, and NormFinder) were used to assess the expression stabilities of the candidate genes. The results showed that ubiquitin-conjugating enzyme (UCE), actin (ACT) and phospholipase A22 (PLA) were the most stable genes in Sacha inchi seedlings. For roots, stems, leaves, flowers, and seeds from adult plants, 30S ribosomal protein S13 (RPS13), cyclophilin (CYC) and elongation factor-1alpha (EF1α) were recommended as reference genes for RT-qPCR. During the development of reproductive organs, PLA, ACT and UCE were the optimal reference genes for flower development, whereas UCE, RPS13 and RNA polymerase II subunit (RPII) were optimal for seed development. Considering the entire growth cycle of Sacha inchi, UCE, ACT and EF1α were sufficient for the purpose of normalization. Our results provide useful guidelines for the selection of reliable reference genes for the normalization of RT-qPCR data for seedlings and adult plants, for reproductive organs, and for the entire growth cycle of Sacha inchi.

Construction of Chinese adult male phantom library and its application in the virtual calibration of in vivo measurement.

PubMed

Chen, Yizheng; Qiu, Rui; Li, Chunyan; Wu, Zhen; Li, Junli

2016-03-07

In vivo measurement is a main method of internal contamination evaluation, particularly for large numbers of people after a nuclear accident. Before the practical application, it is necessary to obtain the counting efficiency of the detector by calibration. The virtual calibration based on Monte Carlo simulation usually uses the reference human computational phantom, and the morphological difference between the monitored personnel with the calibrated phantom may lead to the deviation of the counting efficiency. Therefore, a phantom library containing a wide range of heights and total body masses is needed. In this study, a Chinese reference adult male polygon surface (CRAM_S) phantom was constructed based on the CRAM voxel phantom, with the organ models adjusted to match the Chinese reference data. CRAM_S phantom was then transformed to sitting posture for convenience in practical monitoring. Referring to the mass and height distribution of the Chinese adult male, a phantom library containing 84 phantoms was constructed by deforming the reference surface phantom. Phantoms in the library have 7 different heights ranging from 155 cm to 185 cm, and there are 12 phantoms with different total body masses in each height. As an example of application, organ specific and total counting efficiencies of Ba-133 were calculated using the MCNPX code, with two series of phantoms selected from the library. The influence of morphological variation on the counting efficiency was analyzed. The results show only using the reference phantom in virtual calibration may lead to an error of 68.9% for total counting efficiency. Thus the influence of morphological difference on virtual calibration can be greatly reduced using the phantom library with a wide range of masses and heights instead of a single reference phantom.

A content analysis of the quantity and accuracy of dietary supplement information found in magazines with high adolescent readership.

PubMed

Shaw, Patricia; Zhang, Vivien; Metallinos-Katsaras, Elizabeth

2009-02-01

The objective of this study was to examine the quantity and accuracy of dietary supplement (DS) information through magazines with high adolescent readership. Eight (8) magazines (3 teen and 5 adult with high teen readership) were selected. A content analysis for DS was conducted on advertisements and editorials (i.e., articles, advice columns, and bulletins). Noted claims/cautions regarding DS were evaluated for accuracy using Medlineplus.gov and Naturaldatabase.com. Claims for dietary supplements with three or more types of ingredients and those in advertisements were not evaluated. Advertisements were evaluated with respect to size, referenced research, testimonials, and Dietary Supplement Health and Education Act of 1994 (DSHEA) warning visibility. Eighty-eight (88) issues from eight magazines yielded 238 DS references. Fifty (50) issues from five magazines contained no DS reference. Among teen magazines, seven DS references were found: five in the editorials and two in advertisements. In adult magazines, 231 DS references were found: 139 in editorials and 92 in advertisements. Of the 88 claims evaluated, 15% were accurate, 23% were inconclusive, 3% were inaccurate, 5% were partially accurate, and 55% were unsubstantiated (i.e., not listed in reference databases). Of the 94 DS evaluated in advertisements, 43% were full page or more, 79% did not have a DSHEA warning visible, 46% referred to research, and 32% used testimonials. Teen magazines contain few references to DS, none accurate. Adult magazines that have a high teen readership contain a substantial amount of DS information with questionable accuracy, raising concerns that this information may increase the chances of inappropriate DS use by adolescents, thereby increasing the potential for unexpected effects or possible harm.

Construction of Chinese adult male phantom library and its application in the virtual calibration of in vivo measurement

NASA Astrophysics Data System (ADS)

Chen, Yizheng; Qiu, Rui; Li, Chunyan; Wu, Zhen; Li, Junli

2016-03-01

In vivo measurement is a main method of internal contamination evaluation, particularly for large numbers of people after a nuclear accident. Before the practical application, it is necessary to obtain the counting efficiency of the detector by calibration. The virtual calibration based on Monte Carlo simulation usually uses the reference human computational phantom, and the morphological difference between the monitored personnel with the calibrated phantom may lead to the deviation of the counting efficiency. Therefore, a phantom library containing a wide range of heights and total body masses is needed. In this study, a Chinese reference adult male polygon surface (CRAM_S) phantom was constructed based on the CRAM voxel phantom, with the organ models adjusted to match the Chinese reference data. CRAMS phantom was then transformed to sitting posture for convenience in practical monitoring. Referring to the mass and height distribution of the Chinese adult male, a phantom library containing 84 phantoms was constructed by deforming the reference surface phantom. Phantoms in the library have 7 different heights ranging from 155 cm to 185 cm, and there are 12 phantoms with different total body masses in each height. As an example of application, organ specific and total counting efficiencies of Ba-133 were calculated using the MCNPX code, with two series of phantoms selected from the library. The influence of morphological variation on the counting efficiency was analyzed. The results show only using the reference phantom in virtual calibration may lead to an error of 68.9% for total counting efficiency. Thus the influence of morphological difference on virtual calibration can be greatly reduced using the phantom library with a wide range of masses and heights instead of a single reference phantom.

Health effects models for nuclear power plant accident consequence analysis. Part 1, Introduction, integration, and summary: Revision 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Evans, J.S.; Abrahmson, S.; Bender, M.A.

1993-10-01

This report is a revision of NUREG/CR-4214, Rev. 1, Part 1 (1990), Health Effects Models for Nuclear Power Plant Accident Consequence Analysis. This revision has been made to incorporate changes to the Health Effects Models recommended in two addenda to the NUREG/CR-4214, Rev. 1, Part 11, 1989 report. The first of these addenda provided recommended changes to the health effects models for low-LET radiations based on recent reports from UNSCEAR, ICRP and NAS/NRC (BEIR V). The second addendum presented changes needed to incorporate alpha-emitting radionuclides into the accident exposure source term. As in the earlier version of this report, modelsmore » are provided for early and continuing effects, cancers and thyroid nodules, and genetic effects. Weibull dose-response functions are recommended for evaluating the risks of early and continuing health effects. Three potentially lethal early effects -- the hematopoietic, pulmonary, and gastrointestinal syndromes are considered. Linear and linear-quadratic models are recommended for estimating the risks of seven types of cancer in adults - leukemia, bone, lung, breast, gastrointestinal, thyroid, and ``other``. For most cancers, both incidence and mortality are addressed. Five classes of genetic diseases -- dominant, x-linked, aneuploidy, unbalanced translocations, and multifactorial diseases are also considered. Data are provided that should enable analysts to consider the timing and severity of each type of health risk.« less

The company objects keep: Linking referents together during cross-situational word learning.

PubMed

Zettersten, Martin; Wojcik, Erica; Benitez, Viridiana L; Saffran, Jenny

2018-04-01

Learning the meanings of words involves not only linking individual words to referents but also building a network of connections among entities in the world, concepts, and words. Previous studies reveal that infants and adults track the statistical co-occurrence of labels and objects across multiple ambiguous training instances to learn words. However, it is less clear whether, given distributional or attentional cues, learners also encode associations amongst the novel objects. We investigated the consequences of two types of cues that highlighted object-object links in a cross-situational word learning task: distributional structure - how frequently the referents of novel words occurred together - and visual context - whether the referents were seen on matching backgrounds. Across three experiments, we found that in addition to learning novel words, adults formed connections between frequently co-occurring objects. These findings indicate that learners exploit statistical regularities to form multiple types of associations during word learning.

Reference values for pulmonary diffusing capacity for adult native Finns.

PubMed

Kainu, Annette; Toikka, Jyri; Vanninen, Esko; Timonen, Kirsi L

2017-04-01

Measurement standards for pulmonary diffusing capacity were updated in 2005 by the ATS/ERS Task Force. However, in Finland reference values published in 1982 by Viljanen et al. have been used to date. The main aim of this study was to produce updated reference models for single-breath diffusing capacity for carbon monoxide for Finnish adults. Single-breath diffusing capacity for carbon monoxide was measured in 631 healthy non-smoking volunteers (41.5% male). Reference values for diffusing capacity (DLCO), alveolar volume (VA), diffusing capacity per unit of lung volume (DLCO/VA), and lung volumes were calculated using a linear regression model. Previously used Finnish reference values were found to produce too low predicted values, with mean predicted DLCO 111.0 and 104.4%, and DLCO/VA of 103.5 and 102.7% in males and females, respectively. With the European Coalition for Steel and Coal (ECSC) reference values there was a significant sex difference in DLCO/VA with mean predicted 105.4% in males and 92.8% in females (p < .001). New reference values for DLCO, DLCO/VA, VA, vital capacity (VC), inspiratory vital capacity (IVC), and inspiratory capacity (IC) are suggested for clinical use to replace technically outdated reference values for clinical applications.

Clinical chemistry reference intervals of healthy adult populations in Gojjam Zones of Amhara National Regional State, Northwest Ethiopia

PubMed Central

Amuamuta, Asmare; Mulu, Wondemagegn; Yimer, Mulat; Zenebe, Yohannes; Adem, Yesuf; Abera, Bayeh; Gebeyehu, Wondemu; Gebregziabher, Yakob

2017-01-01

Background Reference interval is crucial for disease screening, diagnosis, monitoring, progression and treatment efficacy. Due to lack of locally derived reference values for the parameters, clinicians use reference intervals derived from western population. But, studies conducted in different African countries have indicated differences between locally and western derived reference values. Different studies also indicated considerable variation in clinical chemistry reference intervals by several variables such as age, sex, geographical location, environment, lifestyle and genetic variation. Objective This study aimed to determine the reference intervals of common clinical chemistry parameters of the community of Gojjam Zones, Northwest Ethiopia. Method Population based cross-sectional study was conducted from November 2015 to December 2016 in healthy adult populations of Gojjam zone. Data such as, medical history, physical examination and socio-demographic data were collected. In addition, laboratory investigations were undertaken to screen the population. Clinical chemistry parameters were measured using Mindray BS 200 clinical chemistry autoanalyzer as per the manufacturer’s instructions. Descriptive statistics was used to calculate mean, median and 95th percentiles. Independent sample T-test and one way ANOVA were used to see association between variables. Results After careful screening of a total of 799 apparently healthy adults who were consented for this study, complete data from 446 (224 females and 222 males) were included for the analysis. The mean age of both the study participants was 28.8 years. Males had high (P<0.05) mean and 2.5th-97.5th percentile ranges of ALT, AST, ALP, creatinine and direct bilirubin. The reference intervals of amylase, LDH, total protein and total bilirubin were not significantly different between the two sex groups (P>0.05). Mean, median, 95% percentile values of AST, ALP, amylase, LDH, creatinine, total protein, total bilirubin, and direct bilirubin across all age groups of participants were similar (P>0.05). But, there was a significant difference in the value of ALT (P<0.05). The reference intervals of ALT, total protein and creatinine were significantly (P<0.05) high in people having monthly income >1500 ETB compared to those with low monthly income. Significant (P<0.05) higher values of the ALT, ALP and total protein were observed in people living in high land compared to low land residences. Conclusion The study showed that some of the common clinical chemistry parameters reference intervals of healthy adults in Gojjam zones were higher than the reference intervals generated from developed countries. Therefore, strict adherence to the reference values generated in developed countries could lead to inappropriate diagnosis and treatment of patients. There was also variation of reference interval values based on climate, gender, age, monthly income and geographical locations. Therefore, further study is required to establish reference intervals for Ethiopian population. PMID:28886191

A Survey of Community Employment Placements: Where Are Youth and Adults with Disabilities Working?.

ERIC Educational Resources Information Center

Morgan, Robert L.; Ellerd, David A.; Jensen, Kari; Taylor, Matthew J.

2000-01-01

A survey of 109 high school transition programs and 55 adult supported employment programs found that of 7,553 job placements for youth and adults with disabilities, the most frequent category was in food and beverage preparation services. Emerging markets for job placements included tourism and casino jobs. (Contains references.) (Author/CR)

Screening and Diagnostic Procedure for Identification of Adult Learning Problems. 309 Demonstration Project.

ERIC Educational Resources Information Center

International Labour Office, Islamabad (Pakistan). Asian and Pacific Skill Development Programme.

This screening and diagnostic procedure is intended to identify Level 1 adults with specific learning problems. The adults not meeting criteria on the assessments for visual and auditory functions should be referred to proper medical services for full evaluations. A prescriptive teaching program should be specifically designed to meet needs of…

Adults' Social Cues Facilitate Young Children's Use of Signs and Symbols

ERIC Educational Resources Information Center

Leekam, Susan R.; Solomon, Tracy L.; Teoh, Yee-San

2010-01-01

Three experiments investigated the effect of an adult's social cues on 2- and 3-year-old children's ability to use a sign or symbol to locate a hidden object. Results showed that an adult's positive, engaging facial expression facilitated children's ability to identify the correct referent, particularly for 3-year-olds. A neutral facial expression…

Impairment in Instrumental Activities of Daily Living and the Geriatric Syndrome of Self-Neglect

ERIC Educational Resources Information Center

Naik, Aanand D.; Burnett, Jason; Pickens-Pace, Sabrina; Dyer, Carmel B.

2008-01-01

Purpose: We sought to characterize self-neglect definitively as a geriatric syndrome by identifying an association with functional impairment. Design and Methods: We performed a cross-sectional home evaluation of 100 community-living older adults referred by Adult Protective Services for geriatric self-neglect and 100 matched adults from a…

The Processing Behaviours of Adult Second Language Learners and Their Relationship to Second Language Proficiency.

ERIC Educational Resources Information Center

Mangubhai, Francis

1991-01-01

Investigated the behaviors for processing language input demonstrated by five adults beginning to learn Hindi as a second language through the Total Physical Response method. The study suggests that, when adult learners are provided with comprehensive input, they engage in a variety of behaviors to extract meaning from it. (73 references) (GLR)

Adult Learners: Why They Are Important to the 21st Century College or University.

ERIC Educational Resources Information Center

Bash, Lee

2003-01-01

College-based adult learning programs are beset by low status, lack of institutional support, cash-cow syndrome, lack of faculty investment, and the dichotomy of traditional/adult students. The academy should embrace an entrepreneurial mission in order to adapt to the challenges of the 21st century. (Contains 15 references.) (SK)

Technical Evaluation of the NASA Model for Cancer Risk to Astronauts Due to Space Radiation

NASA Technical Reports Server (NTRS)

2012-01-01

At the request of NASA, the National Research Council's (NRC's) Committee for Evaluation of Space Radiation Cancer Risk Model reviewed a number of changes that NASA proposes to make to its model for estimating the risk of radiation-induced cancer in astronauts. The NASA model in current use was last updated in 2005, and the proposed model would incorporate recent research directed at improving the quantification and understanding of the health risks posed by the space radiation environment. NASA's proposed model is defined by the 2011 NASA report Space Radiation Cancer Risk Projections and Uncertainties 2010 (Cucinotta et al., 2011). The committee's evaluation is based primarily on this source, which is referred to hereafter as the 2011 NASA report, with mention of specific sections or tables cited more formally as Cucinotta et al. (2011). The overall process for estimating cancer risks due to low linear energy transfer (LET) radiation exposure has been fully described in reports by a number of organizations. They include, more recently: (1) The "BEIR VII Phase 2" report from the NRC's Committee on Biological Effects of Ionizing Radiation (BEIR) (NRC, 2006); (2) Studies of Radiation and Cancer from the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR, 2006), (3) The 2007 Recommendations of the International Commission on Radiological Protection (ICRP), ICRP Publication 103 (ICRP, 2007); and (4) The Environmental Protection Agency s (EPA s) report EPA Radiogenic Cancer Risk Models and Projections for the U.S. Population (EPA, 2011). The approaches described in the reports from all of these expert groups are quite similar. NASA's proposed space radiation cancer risk assessment model calculates, as its main output, age- and gender-specific risk of exposure-induced death (REID) for use in the estimation of mission and astronaut-specific cancer risk. The model also calculates the associated uncertainties in REID. The general approach for estimating risk and uncertainty in the proposed model is broadly similar to that used for the current (2005) NASA model and is based on recommendations by the National Council on Radiation Protection and Measurements (NCRP, 2000, 2006). However, NASA's proposed model has significant changes with respect to the following: the integration of new findings and methods into its components by taking into account newer epidemiological data and analyses, new radiobiological data indicating that quality factors differ for leukemia and solid cancers, an improved method for specifying quality factors in terms of radiation track structure concepts as opposed to the previous approach based on linear energy transfer, the development of a new solar particle event (SPE) model, and the updates to galactic cosmic ray (GCR) and shielding transport models. The newer epidemiological information includes updates to the cancer incidence rates from the life span study (LSS) of the Japanese atomic bomb survivors (Preston et al., 2007), transferred to the U.S. population and converted to cancer mortality rates from U.S. population statistics. In addition, the proposed model provides an alternative analysis applicable to lifetime never-smokers (NSs). Details of the uncertainty analysis in the model have also been updated and revised. NASA's proposed model and associated uncertainties are complex in their formulation and as such require a very clear and precise set of descriptions. The committee found the 2011 NASA report challenging to review largely because of the lack of clarity in the model descriptions and derivation of the various parameters used. The committee requested some clarifications from NASA throughout its review and was able to resolve many, but not all, of the ambiguities in the written description.

Hybrid computational phantoms of the male and female newborn patient: NURBS-based whole-body models

NASA Astrophysics Data System (ADS)

Lee, Choonsik; Lodwick, Daniel; Hasenauer, Deanna; Williams, Jonathan L.; Lee, Choonik; Bolch, Wesley E.

2007-07-01

Anthropomorphic computational phantoms are computer models of the human body for use in the evaluation of dose distributions resulting from either internal or external radiation sources. Currently, two classes of computational phantoms have been developed and widely utilized for organ dose assessment: (1) stylized phantoms and (2) voxel phantoms which describe the human anatomy via mathematical surface equations or 3D voxel matrices, respectively. Although stylized phantoms based on mathematical equations can be very flexible in regard to making changes in organ position and geometrical shape, they are limited in their ability to fully capture the anatomic complexities of human internal anatomy. In turn, voxel phantoms have been developed through image-based segmentation and correspondingly provide much better anatomical realism in comparison to simpler stylized phantoms. However, they themselves are limited in defining organs presented in low contrast within either magnetic resonance or computed tomography images—the two major sources in voxel phantom construction. By definition, voxel phantoms are typically constructed via segmentation of transaxial images, and thus while fine anatomic features are seen in this viewing plane, slice-to-slice discontinuities become apparent in viewing the anatomy of voxel phantoms in the sagittal or coronal planes. This study introduces the concept of a hybrid computational newborn phantom that takes full advantage of the best features of both its stylized and voxel counterparts: flexibility in phantom alterations and anatomic realism. Non-uniform rational B-spline (NURBS) surfaces, a mathematical modeling tool traditionally applied to graphical animation studies, was adopted to replace the limited mathematical surface equations of stylized phantoms. A previously developed whole-body voxel phantom of the newborn female was utilized as a realistic anatomical framework for hybrid phantom construction. The construction of a hybrid phantom is performed in three steps: polygonization of the voxel phantom, organ modeling via NURBS surfaces and phantom voxelization. Two 3D graphic tools, 3D-DOCTOR™ and Rhinoceros™, were utilized to polygonize the newborn voxel phantom and generate NURBS surfaces, while an in-house MATLAB™ code was used to voxelize the resulting NURBS model into a final computational phantom ready for use in Monte Carlo radiation transport calculations. A total of 126 anatomical organ and tissue models, including 38 skeletal sites and 31 cartilage sites, were described within the hybrid phantom using either NURBS or polygon surfaces. A male hybrid newborn phantom was constructed following the development of the female phantom through the replacement of female-specific organs with male-specific organs. The outer body contour and internal anatomy of the NURBS-based phantoms were adjusted to match anthropometric and reference newborn data reported by the International Commission on Radiological Protection in their Publication 89. The voxelization process was designed to accurately convert NURBS models to a voxel phantom with minimum volumetric change. A sensitivity study was additionally performed to better understand how the meshing tolerance and voxel resolution would affect volumetric changes between the hybrid-NURBS and hybrid-voxel phantoms. The male and female hybrid-NURBS phantoms were constructed in a manner so that all internal organs approached their ICRP reference masses to within 1%, with the exception of the skin (-6.5% relative error) and brain (-15.4% relative error). Both hybrid-voxel phantoms were constructed with an isotropic voxel resolution of 0.663 mm—equivalent to the ICRP 89 reference thickness of the newborn skin (dermis and epidermis). Hybrid-NURBS phantoms used to create their voxel counterpart retain the non-uniform scalability of stylized phantoms, while maintaining the anatomic realism of segmented voxel phantoms with respect to organ shape, depth and inter-organ positioning. This work was supported by the National Cancer Institute.

Two-Year-Olds Use Pragmatic Cues to Differentiate Reference to Objects and Actions.

ERIC Educational Resources Information Center

Tomasello, Michael; Akhtar, Nameera

1995-01-01

Attempts to determine whether children can use social-pragmatic cues to determine "what kind" of referent, object, or action an adult intends to indicate with a novel word. Doubts that children assume that a novel word refers to whatever nameless object is present. Suggests that lexical acquisition rests fundamentally on children's…

Young Children Follow Pointing over Words in Interpreting Acts of Reference

ERIC Educational Resources Information Center

Grassmann, Susanne; Tomasello, Michael

2010-01-01

Adults refer young children's attention to things in two basic ways: through the use of pointing (and other deictic gestures) and words (and other linguistic conventions). In the current studies, we referred young children (2- and 4-year-olds) to things in conflicting ways, that is, by pointing to one object while indicating linguistically (in…

Content Knowledge of the Internet Among Public Reference Librarians at the Cleveland Heights Public Library.

ERIC Educational Resources Information Center

Augustine, Matthew J.

The Internet is becoming an increasingly important medium of electronic information dissemination, and thus an increasingly important library reference tool. This study examines the Internet skills of a sample group of 15 public reference librarians in the Adult Services Department at the Cleveland Heights Public Library. The Internet skills that…

Toward Developing a Universal Code of Ethics for Adult Educators.

ERIC Educational Resources Information Center

Siegel, Irwin H.

2000-01-01

Presents conflicting viewpoints on a universal code of ethics for adult educators. Suggests objectives of a code (guidance for practice, policymaking direction, common reference point, shared values). Outlines content and methods for implementing a code. (SK)

Genetics Home Reference: adult-onset leukoencephalopathy with axonal spheroids and pigmented glia

MedlinePlus

... it causes a severe decline in thinking and reasoning abilities (dementia). Over time, motor skills are affected, ... Schmahmann JD. Adult onset leukodystrophy with neuroaxonal spheroids: clinical, neuroimaging and neuropathologic observations. Brain Pathol. 2009 Jan; ...

A Critical Look at Health Literacy.

ERIC Educational Resources Information Center

Greenberg, Daphne

2001-01-01

Discusses health literacy studies in medical journals, definitions of health literacy, ways to recognize patients with low literacy skills, and implications for adult literacy education. Urges more discussion and collaboration between adult literacy and health professionals. (Contains 37 references.) (SK)

Vaccines provided by family physicians.

PubMed

Campos-Outcalt, Doug; Jeffcott-Pera, Michelle; Carter-Smith, Pamela; Schoof, Bellinda K; Young, Herbert F

2010-01-01

This study was conducted to document current immunization practices by family physicians. In 2008 the American Academy of Family Physicians (AAFP) conducted a survey among a random sample of 2,000 of its members who reported spending 80% or more of their time in direct patient care. The survey consisted of questions regarding the demographics of the practice, vaccines that are provided at the physicians' clinical site, whether the practice refers patients elsewhere for vaccines, and participation in the Vaccines for Children (VFC) program. The response rate was 38.5%, 31.8% after non-office-based respondents were deleted. A high proportion of respondents (80% or more) reported providing most routinely recommended child, adolescent, and adult vaccines at their practice sites. The exceptions were rotavirus vaccine for children and herpes zoster vaccine for adults., A significant proportion, however, reported referring elsewhere for some vaccines (44.1% for children and adolescent vaccines and 53.5% for adult vaccines), with the most frequent referral location being a public health department. A higher proportion of solo and 2-physician practices than larger practices reported referring patients. A lack of adequate payment was listed as the reason for referring patients elsewhere for vaccines by one-half of those who refer patients. One-half of responders do not participate in the VFC program. Provision of recommended vaccines by most family physicians remains an important service. Smaller practices have more difficulty offering a full array of vaccine products, and lack of adequate payment contributes to referring patients outside the medical home. The reasons behind the lack of participation in the VFC program deserve further study.

Genetics Home Reference: lactose intolerance

MedlinePlus

... or Free article on PubMed Central Järvelä IE. Molecular genetics of adult-type hypolactasia. Ann Med. 2005;37( ... Citation on PubMed Robayo-Torres CC, Nichols BL. Molecular differentiation of congenital lactase ... Bulletins Genetics Home Reference Celebrates Its ...

Using the Monte Carlo method for assessing the tissue and organ doses of patients in dental radiography

NASA Astrophysics Data System (ADS)

Makarevich, K. O.; Minenko, V. F.; Verenich, K. A.; Kuten, S. A.

2016-05-01

This work is dedicated to modeling dental radiographic examinations to assess the absorbed doses of patients and effective doses. For simulating X-ray spectra, the TASMIP empirical model is used. Doses are assessed on the basis of the Monte Carlo method by using MCNP code for voxel phantoms of ICRP. The results of the assessment of doses to individual organs and effective doses for different types of dental examinations and features of X-ray tube are presented.

Estimation of eye lens doses received by pediatric interventional cardiologists.

PubMed

Alejo, L; Koren, C; Ferrer, C; Corredoira, E; Serrada, A

2015-09-01

Maximum Hp(0.07) dose to the eye lens received in a year by the pediatric interventional cardiologists has been estimated. Optically stimulated luminescence dosimeters were placed on the eyes of an anthropomorphic phantom, whose position in the room simulates the most common irradiation conditions. Maximum workload was considered with data collected from procedures performed in the Hospital. None of the maximum values obtained exceed the dose limit of 20 mSv recommended by ICRP. Copyright © 2015 Elsevier Ltd. All rights reserved.

OSLD energy response performance and dose accuracy at 24 - 1250 keV: Comparison with TLD-100H and TLD-100

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kadir, A. B. A.; Priharti, W.; Samat, S. B.

OSLD was evaluated in terms of energy response and accuracy of the measured dose in comparison with TLD-100H and TLD-100. The OSLD showed a better energy response performance for H{sub p}(10) whereas for H{sub p}(0.07), TLD-100H is superior than the others. The OSLD dose accuracy is comparable with the other two dosimeters since it fulfilled the requirement of the ICRP trumpet graph analysis.

Freeware for reporting radiation dosimetry following the administration of radiopharmaceuticals.

PubMed

Gómez Perales, Jesús Luis; García Mendoza, Antonio

2015-09-01

This work describes the development of a software application for reporting patient radiation dosimetry following radiopharmaceutical administration. The resulting report may be included within the patient's medical records. The application was developed in the Visual Basic programming language. The dosimetric calculations are based on the values given by the International Commission on Radiological Protection (ICRP). The software is available in both Spanish and English and can be downloaded at no cost from www.radiopharmacy.net. Copyright © 2015 Elsevier Ltd. All rights reserved.

Thermoluminescent dosimetry in veterinary diagnostic radiology.

PubMed

Hernández-Ruiz, L; Jimenez-Flores, Y; Rivera-Montalvo, T; Arias-Cisneros, L; Méndez-Aguilar, R E; Uribe-Izquierdo, P

2012-12-01

This paper presents the results of Environmental and Personnel Dosimetry made in a radiology area of a veterinary hospital. Dosimetry was realized using thermoluminescent (TL) materials. Environmental Dosimetry results show that areas closer to the X-ray equipment are safe. Personnel Dosimetry shows important measurements of daily workday in some persons near to the limit established by ICRP. TL results of radiation measurement suggest TLDs are good candidates as a dosimeter to radiation dosimetry in veterinary radiology. Copyright © 2012 Elsevier Ltd. All rights reserved.

Adult Basic Education for Psychiatric Survivors: Survival Skills.

ERIC Educational Resources Information Center

Burstow, Bonnie

2002-01-01

Argues that adult basic educators should assist psychiatric clients in protecting themselves from unwanted intrusion. Identifies skills to be developed through social literacy training: coping with emotional distress, expressing oneself, interpreting social cues, and exercising legal rights. (Contains 12 references.) (SK)

Effects of Aging and Noise on Real-Time Spoken Word Recognition: Evidence from Eye Movements

ERIC Educational Resources Information Center

Ben-David, Boaz M.; Chambers, Craig G.; Daneman, Meredyth; Pichora-Fuller, M. Kathleen; Reingold, Eyal M.; Schneider, Bruce A.

2011-01-01

Purpose: To use eye tracking to investigate age differences in real-time lexical processing in quiet and in noise in light of the fact that older adults find it more difficult than younger adults to understand conversations in noisy situations. Method: Twenty-four younger and 24 older adults followed spoken instructions referring to depicted…

Learning as Transformation: Critical Perspectives on a Theory in Progress. The Jossey-Bass Higher and Adult Education Series.

ERIC Educational Resources Information Center

Mezirow, Jack, Ed.

Stemming from a 1998 Columbia University conference on transformative learning, this 3-part book contains 12 articles that examine the concept of how adults learn to change ("transform") their frames of reference. The following are included in Part One: Developing Concepts of Transformative Learning: "Learning To Think Like an Adult: Core Concepts…

Londrina Activities of Daily Living Protocol: Reproducibility, Validity, and Reference Values in Physically Independent Adults Age 50 Years and Older.

PubMed

Paes, Thaís; Belo, Letícia Fernandes; da Silva, Diego Rodrigues; Morita, Andrea Akemi; Donária, Leila; Furlanetto, Karina Couto; Sant'Anna, Thaís; Pitta, Fabio; Hernandes, Nidia Aparecida

2017-03-01

It is important to assess activities of daily living (ADL) in older adults due to impairment of independence and quality of life. However, there is no objective and standardized protocol available to assess this outcome. Thus, the aim of this study was to verify the reproducibility and validity of a new protocol for ADL assessment applied in physically independent adults age ≥50 y, the Londrina ADL protocol, and to establish an equation to predict reference values of the Londrina ADL protocol. Ninety-three physically independent adults age ≥50 y had their performance in ADL evaluated by registering the time spent to conclude the protocol. The protocol was performed twice. The 6-min walk test, which assesses functional exercise capacity, was used as a validation criterion. A multiple linear regression model was applied, including anthropometric and demographic variables that correlated with the protocol, to establish an equation to predict the protocol's reference values. In general, the protocol was reproducible (intraclass correlation coefficient 0.91). The average difference between the first and second protocol was 5.3%. The new protocol was valid to assess ADL performance in the studied subjects, presenting a moderate correlation with the 6-min walk test (r = -0.53). The time spent to perform the protocol correlated significantly with age (r = 0.45) but neither with weight (r = -0.17) nor with height (r = -0.17). A model of stepwise multiple regression including sex and age showed that age was the only determinant factor to the Londrina ADL protocol, explaining 21% ( P < .001) of its variability. The derived reference equation was: Londrina ADL protocol pred (s) = 135.618 + (3.102 × age [y]). The Londrina ADL protocol was reproducible and valid in physically independent adults age ≥50 y. A reference equation for the protocol was established including only age as an independent variable (r 2 = 0.21), allowing a better interpretation of the protocol's results in clinical practice. Copyright © 2017 by Daedalus Enterprises.

Color, Reference, and Expertise in Language Acquisition

ERIC Educational Resources Information Center

Clark, Eve V.

2006-01-01

In learning the meaning of a new term, children need to fix its reference, learn its conventional meaning, and discover the meanings with which it contrasts. To do this, children must attend to adult speakers--the experts--and to their patterns of use. In the domain of color, children need to identify color terms as such, fix the reference of each…

Real-time processing of gender-marked articles by native and non-native Spanish speakers

PubMed Central

Lew-Williams, Casey; Fernald, Anne

2010-01-01

Three experiments using online processing measures explored whether native and non-native Spanish-speaking adults use gender-marked articles to identify referents of target nouns more rapidly, as shown previously with 3-year-old children learning Spanish as L1 (Lew-Williams & Fernald, 2007). In Experiment 1, participants viewed familiar objects with names of either the same or different grammatical gender while listening to Spanish sentences referring to one object. L1 adults, like L1 children, oriented to the target more rapidly on different-gender trials, when the article was informative about noun identity; however, L2 adults did not. Experiments 2 and 3 controlled for frequency of exposure to article-noun pairs by using novel nouns. L2 adults could not exploit gender information when different article-noun pairs were used in teaching and testing. Experience-related factors may influence how L1 adults and children and L2 adults—who learned Spanish at different ages and in different settings—use grammatical gender in realtime processing. PMID:21076648

Medial prefrontal cortex supports source memory for self-referenced materials in young and older adults

PubMed Central

Leshikar, Eric D.; Duarte, Audrey

2013-01-01

Behavioral evidence suggests that young and older adults show a benefit in source memory accuracy when processing materials in reference to the self. In the young, activity within the medial prefrontal cortex supports this source memory benefit at study. This investigation examined whether the same neural regions support this memory benefit in both age groups. Using fMRI, participants were scanned while studying and retrieving pictures of objects paired with one of three scenes (source) under self-reference and other-reference conditions. At the time of study, half of the items were presented once and half twice, allowing us to match behavioral performance between groups. Both groups showed equivalent source accuracy benefit for objects encoded self-referentially. Activity in the left dorsal medial prefrontal cortex supported subsequent source memory in both age groups for the self-referenced relative to the other-referenced items. At the time of test, source accuracy for both self- and other-referenced items was supported by a network of regions including the precuneus in both age groups. At both study and test, little in the way of age-differences emerged, suggesting that when matched on behavioral performance young and older adults engage similar regions in support of source memory when processing materials in reference to the self; however, when performance was not matched, age differences in functional recruitment were prevalent. These results suggest that by capitalizing on preserved processes (self-referential encoding), older adults can show improvement in memory for source details which typically are not well remembered relative to the young. PMID:23904335

Hematology of the Red-capped parrot (Pionopsitta pileata) and Vinaceous Amazon parrot (Amazona vinacea) in captivity.

PubMed

Schmidt, Elizabeth Moreira dos Santos; Lange, Rogério Ribas; Ribas, Janaciara Moreira; Daciuk, Bárbara Maria; Montiani-Ferreira, Fabiano; Paulillo, Antonio Carlos

2009-03-01

Preliminary reference intervals for hematologic and total plasma protein profiles were determined for nine adult Red-capped parrots (Pionopsitta pileata) (six males and three females) and six Vinaceous Amazon parrots (Amazona vinacea) (two adult males, two adult females, one juvenile, and one nonsexed) from the Curitiba Zoo, Paraná, Brazil. For both Red-capped parrots and Vinaceous Amazon parrots, adult males had higher red blood cell counts than adult females. Regarding white blood cell distribution, differences due to gender were also found for both species of parrots.

Auditory evoked potential P300 in adults: reference values

PubMed Central

Didoné, Dayane Domeneghini; Garcia, Michele Vargas; Oppitz, Sheila Jacques; da Silva, Thalisson Francisco Finamôr; dos Santos, Sinéia Neujahr; Bruno, Rúbia Soares; Filha, Valdete Alves Valentins dos Santos; Cóser, Pedro Luis

2016-01-01

ABSTRACT Objective To establish reference intervals for cognitive potential P300 latency using tone burst stimuli. Methods This study involved 28 participants aged between 18 and 59 years. P300 recordings were performed using a two-channel device (Masbe, Contronic). Electrode placement was as follows: Fpz (ground electrode), Cz (active electrode), M1 and M2 (reference electrodes). Intensity corresponded to 80 dB HL and frequent and rare stimulus frequencies to 1,000Hz and 2,000Hz, respectively. Stimuli were delivered binaurally. Results Mean age of participants was 35 years. Average P300 latency was 305ms. Conclusion Maximum acceptable P300 latency values of 362.5ms (305 + 2SD 28.75) were determined for adults aged 18 to 59 years using the protocol described. PMID:27462895

76 FR 32969 - National Technical Assistance and Dissemination Center for Children Who Are Deaf-Blind; Proposed...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-07

... ``individuals who are deaf-blind'' refers to infants, toddlers, children, youth and young adults through age 21... grants funded under the Projects for Children and Young Adults who are Deaf-Blind program (CFDA Number 84...

Adult Literacy Perspectives.

ERIC Educational Resources Information Center

Taylor, Maurice C., Ed.; Draper, James A., Ed.

This book, intended to serve as a professional reference work, proposes to define the field of Adult Basic Education in its evolution, its contribution to professional education, and the principal problems and issues. The volume contains the following treatises: "Definitions and Evolution of the Concepts" (Thomas); "Selected…

The self-reference effect on episodic memory recollection in young and older adults and Alzheimer's disease.

PubMed

Lalanne, Jennifer; Rozenberg, Johanna; Grolleau, Pauline; Piolino, Pascale

2013-12-01

The Self-reference effect (SRE) on long-term episodic memory and autonoetic consciousness has been investigated in young adults, scarcely in older adults, but never in Alzheimer's patients. Is the functional influence of Selfreference still present when the individual's memory and identity are impaired? We investigated this issue in 60 young subjects, 41 elderly subjects, and 28 patients with Alzheimer's disease, by using 1) an incidental learning task of personality traits in three encoding conditions, inducing variable degrees of depth of processing and personal involvement, 2) a 2- minute retention interval free recall task, and 3) a 20-minute delayed recognition task, combined with a remember-know paradigm. Each recorded score was corrected for errors (intrusions in free recall, false alarms in recognition, and false source memory in remember responses). Compared with alternative encodings, the Self-reference significantly enhanced performance on the free recall task in the young group, and on the recognition task both in the young and older groups but not in the Alzheimer group. The most important finding in the Alzheimer group is that the Self-reference led the most often to a subjective sense of remembering (especially for the positive words) with the retrieval of the correct encoding source. This Self-reference recollection effect in patients was related to independent subjective measures of a positive and definite sense of Self (measured by the Tennessee Self Concept Scale), and to memory complaints in daily life. In conclusion, these results demonstrated the power and robustness of the Self-reference effect on recollection in long-term episodic memory in Alzheimer's disease, albeit the retrieval is considerably reduced. These results should open new perspectives for the development of rehabilitation programs for memory deficits.

Reference values of inspiratory spirometry for Finnish adults.

PubMed

Kainu, Annette; Timonen, Kirsi L; Vanninen, Esko; Sovijärvi, Anssi R

2018-03-07

Inspiratory spirometry is used in evaluation of upper airway disorders e.g. fixed or variable obstruction. There are, however, very few published data on normal values for inspiratory spirometry. The main aim of this study was to produce reference values for inspiratory spirometry for healthy Finnish adults. Inspiratory spirometry was preplanned to a sample of the Finnish spirometry reference values sample. Data was successfully retrieved from 368 healthy nonsmoking adults (132 males) between 19 and 83 years of age. Reference equations were produced for forced inspiratory vital capacity (FIVC), forced inspiratory volume in one second (FIV1), FIV1/FIVC, peak inspiratory flow (PIF) and the ratios of FIV1/forced expiratory volume in one second and PIF/peak expiratory flow. The present values were compared to PIF values from previously used Finnish study of Viljanen et al. (1982) reference values and Norwegian values for FIV1, FIVC and FIV1/FIVC presented by Gulsvik et al. (2001). The predicted values from the Gulsvik et al. (2001), provided a good fit for FIVC, but smaller values for FIV1 with mean 108.3 and 109.1% of predicted values for males and females, respectively. PIF values were 87.4 and 91.2% of Viljanen et al. (1982) predicted values in males and females, respectively. Differences in measurement methods and selection of results may contribute to the observed differences. Inspiratory spirometry is technically more demanding and needs repeatability criteria to improve validity. New reference values are suggested to clinical use in Finland when assessing inspiratory spirometry. Utility of inspiratory to expiratory values indices in assessment of airway collapse need further study.

The Provision of Economics Education for Adults in the U.K. with Special Reference to the London Area. Research Papers in Economics Education.

ERIC Educational Resources Information Center

Freedman, L. T.

The nature of adult economics education provided in the United Kingdom is outlined, and a framework within which it might be investigated is suggested. Androgogical learning principles are critically appraised and are compared and contrasted to pedagogical principles. An adult economics course model is developed, against which actual courses may…

A New Social Capital Paradigm for Adult Literacy: Partnerships, Policy and Pedagogy. An Adult Literacy National Project Report

ERIC Educational Resources Information Center

Balatti, Jo; Black, Stephen; Falk, Ian

2009-01-01

The primary purpose of this project is to produce a set of guidelines on how to deliver adult literacy and numeracy education and training using a social capital approach. Social capital in this project refers to the networks that operate during resourcing, course design, recruitment, teaching and evaluation. The study focused on three specific…

What's Missing When Empowerment Is a Purpose for Adult Literacies Education? Bourdieu, Gee and the Problem of Accounting for Power

ERIC Educational Resources Information Center

Galloway, Sarah

2015-01-01

This writing critiques the idea that literacies education can and should empower adult learners. The ideas of Pierre Bourdieu and James Paul Gee are analysed with reference to how power and empowerment are understood and what this means for the concrete practice of adult literacies education by educators and students. My concern is that their…

Extending Transition to Address Guardianship Alternatives: An Issue Concerning Students Who Have Intellectual Disability

ERIC Educational Resources Information Center

Millar, Dorothy Squatrito

2014-01-01

As students who have intellectual disability reach or have reached the age of majority, concerns regarding their competence to make informed decisions are often raised, as is the issue of adult guardianship. Guardianship refers to when a judge appoints an adult to be the guardian of another adult (ward) who has been determined to be unable to care…

Clinical and genetic characterization of the autoinflammatory diseases diagnosed in an adult reference center.

PubMed

Hernández-Rodríguez, José; Ruíz-Ortiz, Estíbaliz; Tomé, Adrià; Espinosa, Gerard; González-Roca, Eva; Mensa-Vilaró, Anna; Prieto-González, Sergio; Espígol-Frigolé, Georgina; Mensa, Josep; Cardellach, Francesc; Grau, Josep M; Cid, Maria C; Yagüe, Jordi; Aróstegui, Juan I; Cervera, Ricard

2016-01-01

Autoinflammatory diseases (AID) are usually diagnosed during the pediatric age. However, adult-onset disease or diagnosis during adulthood has been occasionally described. To assess the clinical and genetic characteristics of adult patients diagnosed with an AID in an adult referral center for AID. We retrospectively evaluated clinical and genetic features of adult patients (≥16 years) diagnosed with an AID or referred after AID diagnosis to the Clinical Unit of AID, at the Department of Autoimmune Diseases, Hospital Clínic of Barcelona, from 2008 to 2014. During the study period, a genetic study for suspected AID was requested to 90 patients at the Department of Autoimmune Diseases. A final diagnosis of monogenic AID was achieved in 17 patients (19% of patients tested). Five additional cases were diagnosed with periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome and 10 patients with AID were referred from other adult departments. Finally, a total of 32 patients with AID were finally diagnosed or monitored in our Clinical Unit. These included 12 (37.5%) familial Mediterranean fever, 6 (18.8%) tumour necrosis factor-receptor associated periodic syndrome, 8 (25%) cryopirin-associated periodic syndromes (Muckle-Wells syndrome [MWS] or overlap familial cold-associated periodic syndrome/MWS), 1 (3.1%) mevalonate kinase deficiency, and 5 (15.6%) PFAPA. Clinical evidence of disease-onset during childhood and adulthood was observed in 15 (47%) and 17 (53%) patients, respectively. Overall, the final diagnosis was obtained after a delay of a mean of 12 years (range 0-47 years). Compared to children, adult patients with AID in our series presented more frequently with non-severe manifestations and none of them developed amyloidosis during follow-up. Adult patients also carried higher proportion of low-penetrance mutations or polymorphisms and all genetic variants were presented in heterozygosis or as heterozygous compounds. Adult disease-onset or delayed diagnosis of AID during adulthood is associated with milder disease phenotypes, and seem to be driven by mild genotypes, with predominant presence of low-penetrance mutations or polymorphisms. Copyright © 2015 Elsevier B.V. All rights reserved.

GATE based Monte Carlo simulation of planar scintigraphy to estimate the nodular dose in radioiodine therapy for autonomous thyroid adenoma.

PubMed

Hammes, Jochen; Pietrzyk, Uwe; Schmidt, Matthias; Schicha, Harald; Eschner, Wolfgang

2011-12-01

The recommended target dose in radioiodine therapy of solitary hyperfunctioning thyroid nodules is 300-400Gy and therefore higher than in other radiotherapies. This is due to the fact that an unknown, yet significant portion of the activity is stored in extranodular areas but is neglected in the calculatory dosimetry. We investigate the feasibility of determining the ratio of nodular and extranodular activity concentrations (uptakes) from post-therapeutically acquired planar scintigrams with Monte Carlo simulations in GATE. The geometry of a gamma camera with a high energy collimator was emulated in GATE (Version 5). A geometrical thyroid-neck phantom (GP) and the ICRP reference voxel phantoms "Adult Female" (AF, 16ml thyroid) and "Adult Male" (AM, 19ml thyroid) were used as source regions. Nodules of 1ml and 3ml volume were placed in the phantoms. For each phantom and each nodule 200 scintigraphic acquisitions were simulated. Uptake ratios of nodule and rest of thyroid ranging from 1 to 20 could be created by summation. Quantitative image analysis was performed by investigating the number of simulated counts in regions of interest (ROIs). ROIs were created by perpendicular projection of the phantom onto the camera plane to avoid a user dependant bias. The ratio of count densities in ROIs over the nodule and over the contralateral lobe, which should be least affected by nodular activity, was taken to be the best available measure for the uptake ratios. However, the predefined uptake ratios are underestimated by these count density ratios: For an uptake ratio of 20 the count ratios range from 4.5 (AF, 1ml nodule) to 15.3 (AM, 3ml nodule). Furthermore, the contralateral ROI is more strongly affected by nodular activity than expected: For an uptake ratio of 20 between nodule and rest of thyroid up to 29% of total counts in the ROI over the contralateral lobe are caused by decays in the nodule (AF 3 ml). In the case of the 1ml nodules this effect is smaller: 9-11% (AF) respectively 7-8% (AM). For each phantom, the dependency of count density ratios upon uptake ratios can be modeled well by both linear and quadratic regression (quadratic: r(2)>0.99), yielding sets of parameters which in reverse allow the computation of uptake ratios (and thus dose) from count density ratios. A single regression model obtained by fitting the data of all simulations simultaneously did not provide satisfactory results except for GP, while underestimating the true uptake ratios in AF and overestimating them in AM. The scintigraphic count density ratios depend upon the uptake ratios between nodule and rest of thyroid, upon their volumes, and their respective position in a non-trivial way. Further investigations are required to derive a comprehensive rule to calculate the uptake or dose ratios based on post-therapeutic scintigraphy. Copyright © 2011. Published by Elsevier GmbH.

A TEACHER'S GUIDE FOR ADULT BASIC EDUCATION.

ERIC Educational Resources Information Center

BROWN, ANTRONETTE

COMPILED AS AN IDEA AND INFORMATION GUIDE FOR TEACHERS OF ADULT BASIC EDUCATION, THIS DOCUMENT INCLUDES DETAILED TEACHING OBJECTIVES, METHODS, AND MATERIALS (FILMS, FILMSTRIPS, BOOKS, TRANSPARENCIES). THE COURSE INCLUDES (1) READING AND COMMUNICATION SKILLS--PHONICS, VOCABULARY, REFERENCE, AND SO ON, (2) SOCIAL STUDIES--GOVERNMENT, GEOGRAPHY,…

An Annotated Bibliography of Research on Reading and Adults Learning English as a Second Language.

ERIC Educational Resources Information Center

Burt, Miriam, Comp.; Florez, MaryAnn, Comp.; Terrill, Lynda, Comp.; Van Duzer, Carol, Comp.

This annotated bibliography contains 27 references regarding research on reading and adults learning English as a Second Language (ESL). None of the resources are more than 10 years old. (Adjunct ERIC Clearinghouse for ESL Literacy Education) (KFT)

Age Differences in Self-Referencing: Evidence for Common and Distinct Encoding Strategies

PubMed Central

Gutchess, Angela H.; Sokal, Rebecca; Coleman, Jennifer A.; Gotthilf, Gina; Grewal, Lauren; Rosa, Nicole

2014-01-01

Although engagement of medial prefrontal cortex (MPFC) underlies self-referencing of information for younger and older adults, the region has not consistently been implicated across age groups for the encoding of self-referenced information. We sought to determine whether making judgments about others as well as the self influenced findings in the previous study. During an fMRI session, younger and older adults encoded adjectives using only a self-reference task. For items later remembered compared to those later forgotten, both age groups robustly recruited medial prefrontal cortex, indicating common neural regions support encoding across younger and older adults when participants make only self-reference judgments. Focal age differences emerged in regions related to emotional processing and cognitive control, though these differences are more limited than in tasks in which judgments also are made about others. We conclude that making judgments about another person differently affects the ways that younger and older adults make judgments about the self, with results of a follow-up behavioral study supporting this interpretation. PMID:25223905

Paleodemographic age-at-death distributions of two Mexican skeletal collections: a comparison of transition analysis and traditional aging methods.

PubMed

Bullock, Meggan; Márquez, Lourdes; Hernández, Patricia; Ruíz, Fernando

2013-09-01

Traditional methods of aging adult skeletons suffer from the problem of age mimicry of the reference collection, as described by Bocquet-Appel and Masset (1982). Transition analysis (Boldsen et al., 2002) is a method of aging adult skeletons that addresses the problem of age mimicry of the reference collection by allowing users to select an appropriate prior probability. In order to evaluate whether transition analysis results in significantly different age estimates for adults, the method was applied to skeletal collections from Postclassic Cholula and Contact-Period Xochimilco. The resulting age-at-death distributions were then compared with age-at-death distributions for the two populations constructed using traditional aging methods. Although the traditional aging methods result in age-at-death distributions with high young adult mortality and few individuals living past the age of 50, the age-at-death distributions constructed using transition analysis indicate that most individuals who lived into adulthood lived past the age of 50. Copyright © 2013 Wiley Periodicals, Inc.

Risk of eye lens radiation exposure for members of the public.

PubMed

Chevallier, M-A; Rannou, A; Villagrasa, C; Clairand, I

2016-01-01

In 2011, the International Commission on Radiological Protection (ICRP) reviewed its recommendation concerning the equivalent dose limit for the eye lens, lowering it to 20 mSv in a year, for occupational exposure in planned exposure situations. The ICRP's statement does not contain any explicit recommendations regarding the organ dose limit for the eye lens for public exposure. For the moment, no change is proposed. But, to be coherent in the overall approach, the current equivalent limit for the public might be lowered. A similar yardstick than in the former recommendation may be used, that is to say a reduction of 10 times lower than that for occupational exposure. In this context, additional data on potential scenarios for public exposure of the eye lens are necessary. This paper, mainly based on a literature study, aims to provide, as far as possible, an exhaustive list of the situations in which members of the public can be exposed at the level of the eye lens. Once these situations have been defined, some calculations, made to assess the associated doses to the eye lens, are presented. This literature study did not reveal any current situations where members of the public would receive significant radiation doses to the eye lens. Indeed, the situations in which the dose to the eye lens might reach around 1 mSv per year for the public are extremely rare. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Regulating exposure of the lens of the eye to ionising radiations.

PubMed

Thorne, M C

2012-06-01

The International Commission on Radiological Protection (ICRP) has reviewed recent epidemiological evidence suggesting that, for the lens of the eye, the threshold in absorbed dose for the induction of deleterious health effects is about 0.5 Gy. On this basis, the Commission recommends that for occupational exposure in planned exposure situations, the equivalent dose limit for the lens of the eye should be 20 mSv in a year, averaged over defined periods of 5 yr, with exposure not exceeding 50 mSv in any single year. This paper summarises the data that have been taken into account by the ICRP and critically examines whether the proposed downward revision of the dose limit is justified. Overall, it is concluded that the accumulating radiobiological and epidemiological evidence makes it more appropriate to treat cataract induction as a stochastic rather than a deterministic effect. Within this framework, it is illogical to have the same dose limit for the lens of the eye as for the whole body irradiated uniformly. This could be addressed either by removing the special dose limit for the lens of the eye, assigning it an appropriate tissue weighting factor and including it in the computation of the effective dose, or through a composite approach involving the use of a tissue weighting factor for effective dose computations together with a special limit on the equivalent dose to the lens of the eye to ensure that no individual was subject to an unacceptably high risk of induction of clinically significant cataracts.

Alimentary Tract Absorption (f1 Values) for Radionuclides in Local and Regional Fallout from Nuclear Tests

PubMed Central

Ibrahim, Shawki; Simon, Steven L; Bouville, André; Melo, Dunstana; Beck, Harold

2009-01-01

This paper presents gastrointestinal absorption fractions (f1 values) for estimating internal doses from local and regional fallout radionuclides due to nuclear tests. The choice of f1 values are based on specific circumstances of weapons test conditions and a review of reported f1 values for elements in different physical and chemical states. Special attention is given to fallout from nuclear tests conducted at the Marshall Islands. We make a distinction between the f1 values for intakes of radioactive materials immediately after deposition (acute intakes) and intakes that occur in the course of months and years after deposition, following incorporation into terrestrial and aquatic foodstuffs (chronic intakes). Multiple f1 values for different circumstances where persons are exposed to radioactive fallout (e.g. local vs. regional fallout and coral vs. continental tests) are presented when supportive information is available. In some cases, our selected f1 values are similar to those adopted by the ICRP (e.g. iodine and most actinides). However, f1 values for cesium and strontium derived from urine bioassay data of the Marshallese population are notably lower than the generic f1 values recommended by ICRP, particularly for acute intakes from local fallout (0.4 and 0.05 for Cs and Sr, respectively. The f1 values presented here form the first complete set of values relevant to realistic dose assessments for exposure to local or regional radioactive fallout. PMID:20622554

Radiographic progression of silicosis among Japanese tunnel workers in Kochi.

PubMed

Dumavibhat, Narongpon; Matsui, Tomomi; Hoshino, Eri; Rattanasiri, Sasivimol; Muntham, Dittapol; Hirota, Ryoji; Eitoku, Masamitsu; Imanaka, Momo; Muzembo, Basilua Andre; Ngatu, Nlandu Roger; Kondo, Shinichi; Hamada, Norihiko; Suganuma, Narufumi

2013-01-01

The aim of our study was to investigate the natural course of silicosis in terms of radiographic progression among Japanese tunnel workers. Tunnel workers with silicosis were included in our study between January 2008 and June 2011. We retrospectively assessed workers' radiographs from their first through last visits to see whether there was progression. All films were interpreted by two physicians, who had been specially trained in using the ILO (2000) International Classification of Radiographs of Pneumoconioses (ILO/ICRP). We classified the radiographic findings according to the ILO/ICRP. Survival analysis was performed and then presented as time to progression. Subgroup analysis among the progressed group was performed to demonstrate duration of progression. A total of 65 patients, who were no longer exposed to silica for the duration of the study, were included. The mean age at the first visit was 58.60 ± 7.10 years. The incidence rate of progression was 42 per 1,000 person-years with a median time to progression of 17 years. Progression was demonstrated among 33 cases (51%). The mean durations of progression from category 1 to category 4 and category 2 to category 4 were 14.55 and 10.65 years, respectively. Most patients (86%) had radiographic change from category 1 or 2 directly to category 4. Silicosis progressed at a relatively high rate among tunnel workers without further silica exposure. The high probability of progression directly from category 1 to category 4 may lead to further investigation for the improvement of disease prevention.

Alimentary tract absorption (f1 values) for radionuclides in local and regional fallout from nuclear tests.

PubMed

Ibrahim, Shawki A; Simon, Steven L; Bouville, André; Melo, Dunstana; Beck, Harold L

2010-08-01

This paper presents gastrointestinal absorption fractions (f1 values) for estimating internal doses from local and regional fallout radionuclides due to nuclear tests. The choice of f1 values are based on specific circumstances of weapons test conditions and a review of reported f1 values for elements in different physical and chemical states. Special attention is given to fallout from nuclear tests conducted at the Marshall Islands. We make a distinction between the f1 values for intakes of radioactive materials immediately after deposition (acute intakes) and intakes that occur in the course of months and years after deposition, following incorporation into terrestrial and aquatic foodstuffs (chronic intakes). Multiple f1 values for different circumstances where persons are exposed to radioactive fallout (e.g., local vs. regional fallout and coral vs. continental tests) are presented when supportive information is available. In some cases, our selected f1 values are similar to those adopted by the International Commission on Radiological Protection (ICRP) (e.g., iodine and most actinides). However, f1 values for cesium and strontium derived from urine bioassay data of the Marshallese population are notably lower than the generic f1 values recommended by ICRP, particularly for acute intakes from local fallout (0.4 and 0.05 for Cs and Sr, respectively). The f1 values presented here form the first complete set of values relevant to realistic dose assessments for exposure to local or regional radioactive fallout.

Estimation of annual effective dose due to ingestion of natural radionuclides in foodstuffs and water at a proposed uranium mining site in India.

PubMed

Giri, Soma; Jha, V N; Singh, Gurdeep; Tripathi, R M

2013-12-01

To study the distribution of (210)Po, (226)Ra, (230)Th and U(nat) (naturally occurring radioisotopes of uranium [(234)U, (235)U and (238)U]) in food and water around the Bagjata uranium mining area in India. Radionuclides were analyzed in food samples of plant and animal origin after acid digestion. Intake and ingestion dose of the radionuclides were estimated. (210)Po, (226)Ra, (230)Th and U(nat) in all the dietary components ranged widely from < 0.2-36, < 0.02-1.58, < 0.01-2.8 and < 0.017-0.39 Bqkg(-1), respectively. The range of (226)Ra and U(nat) in water was < 3.5-206 and < 12.6-693 mBql(-1), respectively. The intake of radionuclides considering food and water was calculated to be 760 BqY(-1) while the ingestion dose was 601 μSvY(-1). The estimated doses reflect the natural background dose via route of ingestion, which is below the 1 mSvY(-1) limit set by the International Commission on Radiological Protection (ICRP). However, the doses are more than the dose constraint of 300 μSvY(-1) as suggested by the ICRP for members of the public for planned disposal of long-lived radioactive waste. The study confirms that current levels of radionuclides do not pose significant radiological risk to the local inhabitants, but they need close investigation in the near future.

Depth-dose equivalent relationship for cosmic rays at various solar minima

NASA Technical Reports Server (NTRS)

Badhwar, G. D.; Cucinotta, F. A.; O'Neill, P. M.

1993-01-01

Galactic cosmic rays (GCR) pose a serious radiation hazard for long-duration missions. In designing a lunar habitat or a Mars transfer vehicle, the radiation exposure determines the GCR shielding thickness, and hence the weight of spacecraft. Using the spherically symmetric diffusion theory of the solar modulation of GCR, and data on the differential energy spectra of H, He, O, and Fe, from 1965 to 1989, it has been shown that (1) the flux is determined by the diffusion parameter which is a function of the time in the solar cycle, and (2) the fluxes in the 1954 and 1976-1977 solar minima were similar and higher than those in 1965. In this paper, we have extended the spherical solar modulation theory back to 1954. The 1954-1955 GCR flux was nearly the same as that from 1976 to 1977; the 1965 flux values were nearly the same as those in 1986. Using this theory we have obtained the GCR spectra for all the nuclei, and calculated the depth dose as a function of Al thickness. It is shown that the shielding required to stay below 0.5 Sv is 17.5 -3/+8 g/sq cm of Al, and 9 -1.5/+5 g/sq cm to stay below 0.6 Sv. The calculated dose equivalent using the ICRP 60 values for quality factors is about 15 percent higher than that calculated using the ICRP 26 value.

MIRD Pamphlet No. 21: A Generalized Schema for Radiopharmaceutical Dosimetry-Standardization of Nomenclature

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bolch, W E; Eckerman, Keith F; Sgouros, George

2009-03-01

The internal dosimetry schema of the Medical Internal Radiation Dose (MIRD) Committee of the Society of Nuclear Medicine has provided a broad framework for assessment of the absorbed dose to whole organs, tissue subregions, voxelized tissue structures, and individual cellular compartments for use in both diagnostic and therapeutic nuclear medicine. The schema was originally published in 1968, revised in 1976, and republished in didactic form with comprehensive examples as the MIRD primer in 1988 and 1991. The International Commission on Radiological Protection (ICRP) is an organization that also supplies dosimetric models and technical data, for use in providing recommendations formore » limits on ionizing radiation exposure to workers and members of the general public. The ICRP has developed a dosimetry schema similar to that of the MIRD Committee but has used different terminology and symbols for fundamental quantities such as the absorbed fraction, specific absorbed fraction, and various dose coefficients. The MIRD Committee objectives for this pamphlet are 3-fold: to restate its schema for assessment of absorbed dose in a manner consistent with the needs of both the nuclear medicine and the radiation protection communities, with the goal of standardizing nomenclature; to formally adopt the dosimetry quantities equivalent dose and effective dose for use in comparative evaluations of potential risks of radiation-induced stochastic effects to patients after nuclear medicine procedures; and to discuss the need to identify dosimetry quantities based on absorbed dose that address deterministic effects relevant to targeted radionuclide therapy.« less

Preliminary radiological safety assessment for decommissioning of thoria dissolver of the ²³³U pilot plant, Trombay.

PubMed

Priya, S; Srinivasan, P; Gopalakrishnan, R K

2012-01-01

The thoria dissolver, used for separation of (233)U from reactor-irradiated thorium metal and thorium oxide rods, is no longer operational. It was decided to carry out assessment of the radiological status of the dissolver cell for planning of the future decommissioning/dismantling operations. The dissolver interiors are expected to be contaminated with the dissolution remains of irradiated thorium oxide rods in addition to some of the partially dissolved thoria pellets. Hence, (220)Rn, a daughter product of (228)Th is of major radiological concern. Airborne activity of thoron daughters (212)Pb (Th-B) and (212)Bi (Th-C) was estimated by air sampling followed by high-resolution gamma spectrometry of filter papers. By measuring the full-energy peaks counts in the energy windows of (212)Pb, (212)Bi and (208)Tl, concentrations of thoron progeny in the sampled air were estimated by applying the respective intrinsic peak efficiency factors and suitable correction factors for the equilibration effects of (212)Pb and (212)Bi in the filter paper during the delay between sampling and counting. Then the thoron working level (TWL) was evaluated using the International Commission on Radiological Protection (ICRP) methodology. Finally, the potential effective dose to the workers, due to inhalation of thoron and its progeny during dismantling operations was assessed by using dose conversion factors recommended by ICRP. Analysis of filter papers showed a maximum airborne thoron progeny concentration of 30 TWLs inside the dissolver.

Comparison of conversion coefficients for equivalent dose in terms of air kerma for photons using a male adult voxel simulator in sitting and standing posture with geometry of irradiation antero-posterior

NASA Astrophysics Data System (ADS)

Galeano, D. C.; Cavalcante, F. R.; Carvalho, A. B.; Hunt, J.

2014-02-01

The dose conversion coefficient (DCC) is important to quantify and assess effective doses associated with medical, professional and public exposures. The calculation of DCCs using anthropomorphic simulators and radiation transport codes is justified since in-vivo measurement of effective dose is extremely difficult and not practical for occupational dosimetry. DCCs have been published by the ICRP using simulators in a standing posture, which is not always applicable to all exposure scenarios, providing an inaccurate dose estimation. The aim of this work was to calculate DCCs for equivalent dose in terms of air kerma (H/Kair) using the Visual Monte Carlo (VMC) code and the VOXTISS8 adult male voxel simulator in sitting and standing postures. In both postures, the simulator was irradiated by a plane source of monoenergetic photons in antero-posterior (AP) geometry. The photon energy ranged from 15 keV to 2 MeV. The DCCs for both postures were compared and the DCCs for the standing simulator were higher. For certain organs, the difference of DCCs were more significant, as in gonads (48% higher), bladder (16% higher) and colon (11% higher). As these organs are positioned in the abdominal region, the posture of the anthropomorphic simulator modifies the form in which the radiation is transported and how the energy is deposited. It was also noted that the average percentage difference of conversion coefficients was 33% for the bone marrow, 11% for the skin, 13% for the bone surface and 31% for the muscle. For other organs, the percentage difference of the DCCs for both postures was not relevant (less than 5%) due to no anatomical changes in the organs of the head, chest and upper abdomen. We can conclude that is important to obtain DCCs using different postures from those present in the scientific literature.

Overview of the atmospheric ionizing radiation environment monitoring by Bulgarian build instruments

NASA Astrophysics Data System (ADS)

Dachev, Tsvetan; Tomov, Borislav; Matviichuk, Yury; Dimitrov, Plamen; Spurny, Frantisek; Ploc, Ondrej; Uchihori, Yukio; Flueckiger, Erwin; Kudela, Karel; Benton, Eric

2012-10-01

Humans are exposed to ionizing radiation all the time, and it is known that it can induce a variety of harmful biological effects. Consequently, it is necessary to quantitatively assess the level of exposure to this radiation as the basis for estimating risks for their health. Spacecraft and aircraft crews are exposed to elevated levels of cosmic radiation of galactic and solar origin and to secondary radiation produced in the atmosphere, the vehicle structure and its contents. The aircraft crew monitoring is required by the following recommendations of the International Commission on Radiological Protection (ICRP) (ICRP 1990), the European Union (EU) introduced a revised Basic Safety Standards Directive (EC 1997) which, inter alia, included the exposure to cosmic radiation. This approach has been also adopted in other official documents (NCRP 2002). In this overview we present the results of ground based, mountain peaks, aircraft, balloon and rocket radiation environment monitoring by means of a Si-diode energy deposition spectrometer Liulin type developed first in Bulgarian Academy of Sciences (BAS) for the purposes of the space radiation monitoring at MIR and International Space Station (ISS). These spectrometers-dosemeters are further developed, calibrated and used by scientific groups in different countries. Calibration procedures of them are performed at different accelerators including runs in the CERN high-energy reference field, simulating the radiation field at 10 km altitude in the atmosphere and with heavy ions in Chiba, Japan HIMAC accelerator were performed also. The long term aircraft data base were accumulated using specially developed battery operated instrument in 2001-2009 years onboard of A310-300 aircrafts of Czech Air Lines, during 24 about 2 months runs with more than 2000 flights and 13500 flight hours on routes over the Atlantic Ocean mainly. The obtained experimental data are compared with computational models like CARI and EPCARD. The mountain peak measurements are performed with Liulin-6S, Liulin-6MB and Liulin-6M internet based instruments. They use internet module to generate WEB page, which is posted online. The obtained deposited energy spectra, dose and flux data are transmitted via LAN interface by HTTP and FTP protocols. They work online for different periods between 2005 and 2011 at Jungfrau (3453 meters Above Mean Sea Level (AMSL) http://130.92.231.184/); at Lomnicky stit (2633 meters AMSL http://147.213.218.13/) and Moussala (2925 meters AMSL http://beo-db.inrne.bas.bg/moussala/) peaks in Switzerland, Slovakia and Bulgaria. 4 small size battery operated instruments were flown on balloon over south France in June 2000 and NASA balloon over New Mexico, USA on 11th of June 2005. 1 instrument was used in rocket experiment January 2008.

Global nuclear industry views: challenges arising from the evolution of the optimisation principle in radiological protection.

PubMed

Saint-Pierre, S

2012-01-01

Over the last few decades, the steady progress achieved in reducing planned exposures of both workers and the public has been admirable in the nuclear sector. However, the disproportionate focus on tiny public exposures and radioactive discharges associated with normal operations came at a high price, and the quasi-denial of a risk of major accident and related weaknesses in emergency preparedness and response came at an even higher price. Fukushima has unfortunately taught us that radiological protection (RP) for emergency and post-emergency situations can be much more than a simple evacuation that lasts 24-48 h, with people returning safely to their homes soon afterwards. On optimisation of emergency and post-emergency exposures, the only 'show in town' in terms of international RP policy improvements has been the issuance of the 2007 Recommendations of the International Commission on Radiological Protection (ICRP). However, no matter how genuine these improvements are, they have not been 'road tested' on the practical reality of severe accidents. Post-Fukushima, there is a compelling case to review the practical adequacy of key RP notions such as optimisation, evacuation, sheltering, and reference levels for workers and the public, and to amend these notions with a view to making the international RP system more useful in the event of a severe accident. On optimisation of planned exposures, the reality is that, nowadays, margins for further reductions of public doses in the nuclear sector are very small, and the smaller the dose, the greater the extra effort needed to reduce the dose further. If sufficient caution is not exercised in the use of RP notions such as dose constraints, there is a real risk of challenging nuclear power technologies beyond safety reasons. For nuclear new build, it is the optimisation of key operational parameters of nuclear power technologies (not RP) that is of paramount importance to improve their overall efficiency. In pursuing further improvements in the international RP system, it should be clearly borne in mind that the system is generally based on protection against the risk of cancer and hereditary diseases. The system also protects against deterministic non-cancer effects on tissues and organs. In seeking refinements of such protective notions, ICRP is invited to pay increased attention to the fact that a continued balance must be struck between beneficial activities that cause exposures and protection. The global nuclear industry is committed to help overcome these key RP issues as part of the RP community's upcoming international deliberations towards a more efficient international RP system. Copyright © 2012. Published by Elsevier Ltd.

Organ doses for reference adult male and female undergoing computed tomography estimated by Monte Carlo simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Choonsik; Kim, Kwang Pyo; Long, Daniel

2011-03-15

Purpose: To develop a computed tomography (CT) organ dose estimation method designed to readily provide organ doses in a reference adult male and female for different scan ranges to investigate the degree to which existing commercial programs can reasonably match organ doses defined in these more anatomically realistic adult hybrid phantomsMethods: The x-ray fan beam in the SOMATOM Sensation 16 multidetector CT scanner was simulated within the Monte Carlo radiation transport code MCNPX2.6. The simulated CT scanner model was validated through comparison with experimentally measured lateral free-in-air dose profiles and computed tomography dose index (CTDI) values. The reference adult malemore » and female hybrid phantoms were coupled with the established CT scanner model following arm removal to simulate clinical head and other body region scans. A set of organ dose matrices were calculated for a series of consecutive axial scans ranging from the top of the head to the bottom of the phantoms with a beam thickness of 10 mm and the tube potentials of 80, 100, and 120 kVp. The organ doses for head, chest, and abdomen/pelvis examinations were calculated based on the organ dose matrices and compared to those obtained from two commercial programs, CT-EXPO and CTDOSIMETRY. Organ dose calculations were repeated for an adult stylized phantom by using the same simulation method used for the adult hybrid phantom. Results: Comparisons of both lateral free-in-air dose profiles and CTDI values through experimental measurement with the Monte Carlo simulations showed good agreement to within 9%. Organ doses for head, chest, and abdomen/pelvis scans reported in the commercial programs exceeded those from the Monte Carlo calculations in both the hybrid and stylized phantoms in this study, sometimes by orders of magnitude. Conclusions: The organ dose estimation method and dose matrices established in this study readily provides organ doses for a reference adult male and female for different CT scan ranges and technical parameters. Organ doses from existing commercial programs do not reasonably match organ doses calculated for the hybrid phantoms due to differences in phantom anatomy, as well as differences in organ dose scaling parameters. The organ dose matrices developed in this study will be extended to cover different technical parameters, CT scanner models, and various age groups.« less

Tutor Reference Manual. Second Edition.

ERIC Educational Resources Information Center

Clark, John T., Ed.; Williams, Ron, Jr., Ed.

This manual, intended for use by tutors working with adults learning to read, offers a consolidated resource of specific instructional techniques and provides additional suggestions not covered in basic tutoring workshops. The manual summarizes a variety of approaches commonly used to instruct adults and provides background for three modes of…

Prescribing an Exercise Program and Motivating Older Adults To Comply.

ERIC Educational Resources Information Center

Resnick, Barbara

2001-01-01

To help motivate older adults to initiate and adhere to an exercise program, a seven-step approach was developed: education about benefits, screening, goal setting, exposure to exercise, exposure to role models, verbal encouragement from credible sources, and reinforcement and rewards. (Contains 65 references.) (SK)

Informativeness of Self-Reports of ADHD Symptoms in Monitoring Response to Stimulant Treatment in Clinically Referred Adults With ADHD.

PubMed

Biederman, Joseph; Fitzgerald, Maura; Spencer, Thomas J; Adler, Lenard A; Abrams, Jessica; Biederman, Itai; Faraone, Stephen V

2018-05-01

To investigate the informativeness of self-reports of ADHD symptoms in adults with ADHD in the clinical setting. Subjects were clinically referred adults aged 19 years to 67 years of age of both sexes ( N = 54). All subjects were on stable doses of stimulant and were considered responders to treatment. ADHD symptoms were assessed using the ADHD Investigator Symptom Rating Scale (AISRS) and the ADHD Self-Report Scale (ASRS). Spearman's rank correlations were used to assess the correlations between clinician-assessed ADHD and patients' self-reports. Spearman's rank correlation analysis found evidence of a strong, positive association between total scores on the AISRS and the ASRS ( rs = .65, df = 52, p< .001). Results have important implications for the management and monitoring of treatment response in the clinical setting through patients' self-report.