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Sample records for fluoroscopic dose assessment

  1. Intraoperative fluoroscopic dose assessment in prostate brachytherapy patients.

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    Reed, Daniel R; Wallner, Kent E; Narayanan, Sreeram; Sutlief, Steve G; Ford, Eric C; Cho, Paul S

    2005-09-01

    To evaluate a fluoroscopy-based intraoperative dosimetry system to guide placement of additional sources to underdosed areas, and perform computed tomography (CT) verification. Twenty-six patients with prostate carcinoma treated with either I-125 or Pd-103 brachytherapy at the Puget Sound VA using intraoperative postimplant dosimetry were analyzed. Implants were performed by standard techniques. After completion of the initial planned brachytherapy procedure, the initial fluoroscopic intraoperative dose reconstruction analysis (I-FL) was performed with three fluoroscopic images acquired at 0 (AP), +15, and -15 degrees. Automatic seed identification was performed and the three-dimensional (3D) seed coordinates were computed and imported into VariSeed for dose visualization. Based on a 3D assessment of the isodose patterns additional seeds were implanted, and the final fluoroscopic intraoperative dose reconstruction was performed (FL). A postimplant computed tomography (CT) scan was obtained after the procedure and dosimetric parameters and isodose patterns were analyzed and compared. An average of 4.7 additional seeds were implanted after intraoperative analysis of the dose coverage (I-FL), and a median of 5 seeds. After implantation of additional seeds the mean V100 increased from 89% (I-FL) to 92% (FL) (p sources to supplement inadequately dosed areas within the prostate gland. Additionally, guided implantation of additional source, can significantly improve V100s and D90s, without significantly increasing rectal doses.

  2. Skin dose mapping for fluoroscopically guided interventions

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    Johnson, Perry B.; Borrego, David; Balter, Stephen; Johnson, Kevin; Siragusa, Daniel; Bolch, Wesley E. [Biomedical Engineering, University of Florida, Gainesville, Florida 32611 (United States); Radiology, Columbia University Medical Center, New York, New York 10032 (United States); Radiology, University of Florida, Jacksonville, Florida 32209 (United States); Radiology, Division of Vascular Interventional Radiology, University of Florida, Jacksonville, Florida 32209 (United States); Biomedical Engineering, University of Florida, Gainesville, Florida 32611 (United States)

    2011-10-15

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

  3. Patient Doses in Paediatric Fluoroscopic Examinations in Finland

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    Servomaa, A.; Komppa, T.; Heikkila, M.; Parviainen, T

    2000-07-01

    Dose-area products (DAP) in paediatric fluoroscopic examinations were measured at paediatric clinics in three university hospitals. The purpose was to provide supplementary data for development of reference doses, and for determination of relations between patient size and dose, in examinations involving both radiography and fluoroscopy for paediatric patients of various ages. The number of paediatric patients was 217. The most common fluoroscopic examinations were: micturating cystourethrography (MCU), 103 patients; barium enema (anography), 39 patients; barium meal and follow, 20 patients; and oesophagus, nine patients. Data on the patients and examination techniques, and the dose-area products are reported for various examinations and age groups. In the MCU examinations the mean DAP values were 560 mGy.cm{sup 2} for the age group of 0 years: 910 mGy.cm{sup 2} for the age group of 1-4 years; 880 mGy.cm{sup 2} for the age group of 5-9 years; and 4600 mGy.cm{sup 2} for the age group of 10-15 years. The radiation doses to which paediatric patients are exposed in fluoroscopic examinations vary over a large scale, even within narrow age bands, and comparisons between the doses are difficult because of wide ranges in patient size. This indicates the need for developing a method for taking account of the effects of patients size before deriving reference doses. (author)

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

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    Lubis, L. E.; Badawy, M. K.

    2016-03-01

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

  5. Dose reduction during fluoroscopic placement of feeding tubes

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    Rudin, S.; Bednarek, D.R.; Miller, J.A. (State Univ. of New York, Buffalo (USA))

    1991-03-01

    By both increasing the optical iris of the video camera and removing the grid in fluoroscopic procedures involved in placement of a Dubbhoff feeding tube, the radiation dose to patients and staff was reduced by five to seven times. An average expected dose to a patient of about 300 mGy per procedure was reduced by two to three times when the grid was removed and by an additional three times when an iris of increased diameter was used. Because Dobbhoff procedures do not involve obtaining a diagnosis, the image degradation was acceptable and did not affect the total exposure times or ability to conduct the procedure. With the grid out, the difference between the mean exposure times of 5.1 minutes in 96 patient studies done with a normal iris opening and 4.0 minutes in 52 studies done with an enlarged iris was not statistically significant. The importance of reducing patient dose is reinforced by the finding that one-third of the patients underwent repeated procedures, accounting for almost 60% of the total.

  6. Patient doses from fluoroscopically guided cardiac procedures in pediatrics

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

    2007-08-01

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

  7. Minimizing radiation dose to patient and staff during fluoroscopic, nasoenteral tube insertions

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    Rudin, S.; Bednarek, D.R. (New York Univ., NY (United States). School of Medicine)

    1992-02-01

    Since the fluoroscopic image during nasoenteral tube placements is used for guidance and not for diagnosis, a lower contrast image with increased quantum mottle can be easily tolerated. The three methods to reduce the radiation dose rate investigated consisted of removing camera from the image intensifier output phosphor, and setting the fluoroscopic mA to the minimum value so that the kVp could be maximized. Fluoroscopic frozen video frames of a clinical tube insertion comparing the images with and without the dose-saving techniques are presented. Measurements of the radiation dose rates using a Plexiglas phantom show that the dose for patient and staff during fluoroscopic-guided nasoenteral tube placements can be reduced by over a factor of 10 without significantly adversely affecting the actual placement procedure. (author).

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

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

    2015-06-15

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

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

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

    2015-11-01

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

  10. Radiation Dose Reduction Methods For Use With Fluoroscopic Imaging, Computers And Implications For Image Quality

    Science.gov (United States)

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

    1988-06-01

    The use of a beam splitting device for medical gastro-intestinal fluoroscopy has demonstrated that clinical images obtained with a 100mm photofluorographic camera, and a 1024 X 1024 digital matrix with pulsed progressive readout acquisition techniques, are identical. In addition, it has been found that clinical images can be obtained with digital systems at dose levels lower than those possible with film. The use of pulsed fluoroscopy with intermittent storage of the fluoroscopic image has also been demonstrated to reduce the fluoroscopy part of the examination to very low dose levels, particularly when low repetition rates of about 2 frames per second (fps) are used. The use of digital methods reduces the amount of radiation required and also the heat generated by the x-ray tube. Images can therefore be produced using a very small focal spot on the x-ray tube, which can produce further improvement in the resolution of the clinical images.

  11. Improved-resolution real-time skin-dose mapping for interventional fluoroscopic procedures

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    Rana, Vijay K.; Rudin, Stephen; Bednarek, Daniel R.

    2014-03-01

    We have developed a dose-tracking system (DTS) that provides a real-time display of the skin-dose distribution on a 3D patient graphic during fluoroscopic procedures. Radiation dose to individual points on the skin is calculated using exposure and geometry parameters from the digital bus on a Toshiba C-arm unit. To accurately define the distribution of dose, it is necessary to use a high-resolution patient graphic consisting of a large number of elements. In the original DTS version, the patient graphics were obtained from a library of population body scans which consisted of larger-sized triangular elements resulting in poor congruence between the graphic points and the x-ray beam boundary. To improve the resolution without impacting real-time performance, the number of calculations must be reduced and so we created software-designed human models and modified the DTS to read the graphic as a list of vertices of the triangular elements such that common vertices of adjacent triangles are listed once. Dose is calculated for each vertex point once instead of the number of times that a given vertex appears in multiple triangles. By reformatting the graphic file, we were able to subdivide the triangular elements by a factor of 64 times with an increase in the file size of only 1.3 times. This allows a much greater number of smaller triangular elements and improves resolution of the patient graphic without compromising the real-time performance of the DTS and also gives a smoother graphic display for better visualization of the dose distribution.

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

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

    2015-06-15

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

  13. Incorporating Corrections for the Head-Holder and Compensation Filter when Calculating Skin Dose during Fluoroscopically-Guided Interventions

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    Vijayan, Sarath; Rana, Vijay K.; Rudin, Stephen; Bednarek, Daniel R.

    2015-01-01

    The skin dose tracking system (DTS) that we developed provides a color-coded illustration of the cumulative skin dose distribution on a 3D graphic of the patient during fluoroscopic procedures for immediate feedback to the interventionist. To improve the accuracy of dose calculation, we now have incorporated two additional important corrections (1) for the holder used to immobilize the head in neuro-interventions and (2) for the built-in compensation filters used for beam equalization. Both devices have been modeled in the DTS software so that beam intensity corrections can be made. The head-holder is modeled as two concentric hemi-cylindrical surfaces such that the path length between those surfaces can be determined for rays to individual points on the skin surface. The head-holder on the imaging system we used was measured to attenuate the primary x-rays by 10 to 20% for normal incidence, and up to 40% at non-normal incidence. In addition, three compensation filters of different shape are built into the collimator apparatus and were measured to have attenuation factors ranging from 58% to 99%, depending on kVp and beam filtration. These filters can translate and rotate in the beam and their motion is tracked by the DTS using the digital signal from the imaging system. When it is determined that a ray to a given point on the skin passes through the compensation filter, the appropriate attenuation correction is applied. These corrections have been successfully incorporated in the DTS software to provide a more accurate determination of skin dose. PMID:26819488

  14. Incorporating corrections for the head-holder and compensation filter when calculating skin dose during fluoroscopically guided interventions

    Science.gov (United States)

    Vijayan, Sarath; Rana, Vijay K.; Rudin, Stephen; Bednarek, Daniel R.

    2015-03-01

    The skin dose tracking system (DTS) that we developed provides a color-coded illustration of the cumulative skin dose distribution on a 3D graphic of the patient during fluoroscopic procedures for immediate feedback to the interventionist. To improve the accuracy of dose calculation, we now have incorporated two additional important corrections (1) for the holder used to immobilize the head in neuro-interventions and (2) for the built-in compensation filters used for beam equalization. Both devices have been modeled in the DTS software so that beam intensity corrections can be made. The head-holder is modeled as two concentric hemi-cylindrical surfaces such that the path length between those surfaces can be determined for rays to individual points on the skin surface. The head-holder on the imaging system we used was measured to attenuate the primary x-rays by 10 to 20% for normal incidence, and up to 40% at non-normal incidence. In addition, three compensation filters of different shape are built into the collimator apparatus and were measured to have attenuation factors ranging from 58% to 99%, depending on kVp and beam filtration. These filters can translate and rotate in the beam and their motion is tracked by the DTS using the digital signal from the imaging system. When it is determined that a ray to a given point on the skin passes through the compensation filter, the appropriate attenuation correction is applied. These corrections have been successfully incorporated in the DTS software to provide a more accurate determination of skin dose.

  15. Incorporating Corrections for the Head-Holder and Compensation Filter when Calculating Skin Dose during Fluoroscopically-Guided Interventions.

    Science.gov (United States)

    Vijayan, Sarath; Rana, Vijay K; Rudin, Stephen; Bednarek, Daniel R

    2015-03-18

    The skin dose tracking system (DTS) that we developed provides a color-coded illustration of the cumulative skin dose distribution on a 3D graphic of the patient during fluoroscopic procedures for immediate feedback to the interventionist. To improve the accuracy of dose calculation, we now have incorporated two additional important corrections (1) for the holder used to immobilize the head in neuro-interventions and (2) for the built-in compensation filters used for beam equalization. Both devices have been modeled in the DTS software so that beam intensity corrections can be made. The head-holder is modeled as two concentric hemi-cylindrical surfaces such that the path length between those surfaces can be determined for rays to individual points on the skin surface. The head-holder on the imaging system we used was measured to attenuate the primary x-rays by 10 to 20% for normal incidence, and up to 40% at non-normal incidence. In addition, three compensation filters of different shape are built into the collimator apparatus and were measured to have attenuation factors ranging from 58% to 99%, depending on kVp and beam filtration. These filters can translate and rotate in the beam and their motion is tracked by the DTS using the digital signal from the imaging system. When it is determined that a ray to a given point on the skin passes through the compensation filter, the appropriate attenuation correction is applied. These corrections have been successfully incorporated in the DTS software to provide a more accurate determination of skin dose.

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

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

    2014-06-01

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

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

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

    2015-06-01

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

  18. Calculation of patient effective dose and scattered dose for dental mobile fluoroscopic equipment: application of the Monte Carlo simulation.

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    Lee, Boram; Lee, Jungseok; Kang, Sangwon; Cho, Hyelim; Shin, Gwisoon; Lee, Jeong-Woo; Choi, Jonghak

    2013-01-01

    The objective of this study was to evaluate the patient effective dose and scattered dose from recently developed dental mobile equipment in Korea. The MCNPX 2.6 (Los Alamos National Laboratory, USA) was used in a Monte Carlo simulation to calculate both the effective and scattered doses. The MCNPX code was constructed identically as in the general use of equipment and the effective dose and scattered dose were calculated using the KTMAN-2 digital phantom. The effective dose was calculated as 906 μSv. The equivalent doses per organ were calculated via the MCNPX code, and were 32 174 and 19 μSv in the salivary gland and oesophagus, respectively. The scattered dose of 22.5-32.6 μSv of the tube side at 25 cm from the centre in anterior and posterior planes was measured as 1.4-3 times higher than the detector side of 10.5-16.0 μSv.

  19. Assessing validation of dual fluoroscopic image matching method for measurement of in vivo spine kinematics

    Institute of Scientific and Technical Information of China (English)

    BAI Jian-qiang; HU Yong-cheng; DU Li-qing; HE Jing-liang; LIU Kai; LIU Zhong-jun; XIA Qun

    2011-01-01

    Background Accurate knowledge of the spinal structural functions is critical to understand the biomechanical factors that affect spinal pathology. Many studies have investigated the human vertebral motion both in vitro and in vivo.However, determination of in vivo motion of the vertebrae under physiologic loading conditions remains a challenge in biomedical engineering because of the limitations of current technology and the complicated anatomy of the spine.Methods For in vitro validation, a human lumbar specimen was imbedded with steel beads and moved to a known distance by an universal testing machine (UTM). The dual fluoroscopic system was used to capture the spine motion and reproduce the moving distance. For in vivo validation, a living subject moved the spine in various positions while bearing weight. The fluoroscopes were used to reproduce the in vivo spine positions 5 times. The standard deviations in translation and orientation of the five measurements were used to evaluate the repeatability of technique. The accuracy of vertebral outline matching with metallic marks matching technology was compared.Results The translation positions of the human lumbar specimen could be determined with a mean accuracy less than 0.35 mm and a mean repeatability 0.36 mm for the image matching technique. The repeatability of the method in reproducing in vivo human spine six degrees of freedom (6DOF) kinematics was less than 0.43 mm in translation and less than 0.65° in rotation. The accuracy of metallic marks and vertebral outline matching did not show significant difference.Conclusions Combining a dual fluoroscopic and computerized tomography imaging technique was accurate and reproduceable for noninvasive measurement of spine vertebral motion. The vertebral outline matching technique could be a useful technique for matching of vertebral positions and orientations which can evaluate and improve the efficacy of the various surgical treatments.

  20. Integration of kerma-area product and cumulative air kerma determination into a skin dose tracking system for fluoroscopic imaging procedures

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    Vijayan, Sarath; Shankar, Alok; Rudin, Stephen; Bednarek, Daniel R.

    2016-03-01

    The skin dose tracking system (DTS) that we developed provides a color-coded mapping of the cumulative skin dose distribution on a 3D graphic of the patient during fluoroscopic procedures in real time. The DTS has now been modified to also calculate the kerma area product (KAP) and cumulative air kerma (CAK) for fluoroscopic interventions using data obtained in real-time from the digital bus on a Toshiba Infinix system. KAP is the integral of air kerma over the beam area and is typically measured with a large-area transmission ionization chamber incorporated into the collimator assembly. In this software, KAP is automatically determined for each x-ray pulse as the product of the air kerma/ mAs from a calibration file for the given kVp and beam filtration times the mAs per pulse times the length and width of the beam times a field nonuniformity correction factor. Field nonuniformity is primarily the result of the heel effect and the correction factor was determined from the beam profile measured using radio-chromic film. Dividing the KAP by the beam area at the interventional reference point provides the area averaged CAK. The KAP and CAK per x-ray pulse are summed after each pulse to obtain the total procedure values in real-time. The calculated KAP and CAK were compared to the values displayed by the fluoroscopy machine with excellent agreement. The DTS now is able to automatically calculate both KAP and CAK without the need for measurement by an add-on transmission ionization chamber.

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

    Science.gov (United States)

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

    2012-05-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-03-15

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

  3. Assessment of internal doses

    CERN Document Server

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

    2002-01-01

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

  4. Dose reduction in fluoroscopic interventions using a combination of a region of interest (ROI) x-ray attenuator and spatially different, temporally variable temporal filtering

    Science.gov (United States)

    Swetadri Vasan, S. N.; Pope, Liza; Ionita, Ciprian N.; Titus, A. H.; Bednarek, D. R.; Rudin, S.

    2013-03-01

    A novel dose reduction technique for fluoroscopic interventions involving a combination of a material x-ray region of interest (ROI) attenuator and spatially different, temporally variable ROI temporal recursive filter, was used to guide the catheter to the ROI in three live animal studies, two involving rabbits and one involving a sheep. In the two rabbit studies presented , a catheter was guided to the entrance of the carotid artery. With the added ROI attenuator the image under the high attenuation region is very noisy. By using temporal filtering with a filter weight of 0.6 on previous frames, the noise is reduced. In the sheep study the catheter was guided to the descending aorta of the animal. The sheep offered a relatively higher attenuation to the incident x-rays and thus a higher temporal filter weight of 0.8 on previous frames was used during the procedure to reduce the noise to levels acceptable by the interventionalist. The image sequences from both studies show that significant dose reduction of 5-6 times can be achieved with acceptable image quality outside the ROI by using the above mentioned technique. Even though the temporal filter weighting outside the ROI is higher, the consequent lag does not prevent perception of catheter movement.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Deukwoo; Little, Mark P.; Miller, Donald L. [Radiation Epidemiology Branch, National Cancer Institute, Division of Cancer Epidemiology and Genetics, Bethesda, Maryland 20852-7238 (United States); Radiation Epidemiology Branch, National Cancer Institute, Division of Cancer Epidemiology and Genetics, Bethesda, Maryland 20852-7238 and Department of Radiology and Radiological Sciences, F. Edward Hebert School of Medicine, Uniformed Services University, Bethesda, Maryland 20814 (United States)

    2011-07-15

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

  6. Utirik Atoll Dose Assessment

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-10-06

    On March 1, 1954, radioactive fallout from the nuclear test at Bikini Atoll code-named BRAVO was deposited on Utirik Atoll which lies about 187 km (300 miles) east of Bikini Atoll. The residents of Utirik were evacuated three days after the fallout started and returned to their atoll in May 1954. In this report we provide a final dose assessment for current conditions at the atoll based on extensive data generated from samples collected in 1993 and 1994. The estimated population average maximum annual effective dose using a diet including imported foods is 0.037 mSv y{sup -1} (3.7 mrem y{sup -1}). The 95% confidence limits are within a factor of three of their population average value. The population average integrated effective dose over 30-, 50-, and 70-y is 0.84 mSv (84, mrem), 1.2 mSv (120 mrem), and 1.4 mSv (140 mrem), respectively. The 95% confidence limits on the population-average value post 1998, i.e., the 30-, 50-, and 70-y integral doses, are within a factor of two of the mean value and are independent of time, t, for t > 5 y. Cesium-137 ({sup 137}Cs) is the radionuclide that contributes most of this dose, mostly through the terrestrial food chain and secondarily from external gamma exposure. The dose from weapons-related radionuclides is very low and of no consequence to the health of the population. The annual background doses in the U. S. and Europe are 3.0 mSv (300 mrem), and 2.4 mSv (240 mrem), respectively. The annual background dose in the Marshall Islands is estimated to be 1.4 mSv (140 mrem). The total estimated combined Marshall Islands background dose plus the weapons-related dose is about 1.5 mSv y{sup -1} (150 mrem y{sup -1}) which can be directly compared to the annual background effective dose of 3.0 mSv y{sup -1} (300 mrem y{sup -1}) for the U. S. and 2.4 mSv y{sup -1} (240 mrem y{sup -1}) for Europe. Moreover, the doses listed in this report are based only on the radiological decay of {sup 137}Cs (30.1 y half-life) and other

  7. SU-E-I-22: Dependence On Calibration Phantom and Field Area of the Conversion Factor Used to Calculate Skin Dose During Neuro-Interventional Fluoroscopic Procedures

    Energy Technology Data Exchange (ETDEWEB)

    Rana, V K; Vijayan, S [Physiology and Biophysics, Toshiba Stroke and Vascular Research Center, University at Buffalo (State University of New York), Buffalo, NY (United States); Rudin, S R; Bednarek, D R [Department of Radiology, Physiology and Biophysics, Toshiba Stroke and Vascular Research Center, University at Buffalo (State University of New York), Buffalo, NY (United States)

    2014-06-01

    Purpose: To determine the appropriate calibration factor to use when calculating skin dose with our real-time dose-tracking system (DTS) during neuro-interventional fluoroscopic procedures by evaluating the difference in backscatter from different phantoms and as a function of entrance-skin field area. Methods: We developed a dose-tracking system to calculate and graphically display the cumulative skin-dose distribution in real time. To calibrate the DTS for neuro-interventional procedures, a phantom is needed that closely approximates the scattering properties of the head. We compared the x-ray backscatter from eight phantoms: 20-cm-thick solid water, 16-cm diameter water-filled container, 16-cm CTDI phantom, modified-ANSI head phantom, 20-cm-thick PMMA, Kyoto-Kagaku PBU- 50 head, Phantom-Labs SK-150 head, and RSD RS-240T head. The phantoms were placed on the patient table with the entrance surface at 15 cm tube-side from the isocenter of a Toshiba Infinix C-arm, and the entrance-skin exposure was measured with a calibrated 6-cc PTW ionization chamber. The measurement included primary radiation, backscatter from the phantom and forward scatter from the table and pad. The variation in entrance-skin exposure was also measured as a function of the skin-entrance area for a 30x30 cm by 20-cm-thick PMMA phantom and the SK-150 head phantom using four different added beam filters. Results: The entranceskin exposure values measured for eight different phantoms differed by up to 12%, while the ratio of entrance exposure of all phantoms relative to solid water showed less than 3% variation with kVp. The change in entrance-skin exposure with entrance-skin area was found to differ for the SK-150 head compared to the 20-cm PMMA phantom and the variation with field area was dependent on the added beam filtration. Conclusion: To accurately calculate skin dose for neuro-interventional procedures with the DTS, the phantom for calibration should be carefully chosen since different

  8. PILOT STUDY TO ASSESS MEAL PROGRESSION THROUGH THE GASTROINTESTINAL TRACT OF HABITUATED DOGS DETERMINED BY FLUOROSCOPIC IMAGING WITHOUT SEDATION OR PHYSICAL RESTRAINT.

    Science.gov (United States)

    Wrigglesworth, David J; Bailey, Michael Q; Colyer, Alison; Hughes, Kevin R

    2016-11-01

    A limiting factor of radiographic contrast studies is the requirement for restraint of the animal in order to reduce movement artifacts. To demonstrate that gastrointestinal transit can be analyzed by a barium meal in nonsedated and unrestrained dogs, a pilot study of six adult Labrador retriever dogs was undertaken. Study subjects were selected by convenience sampling from an available population of Labrador dogs and were trained to stand motionless during radiographic fluoroscopy. Following a meal containing 7% w/w powdered barium sulfate, radiographic images were generated using a digital fluoroscope C-arm, at intervals of 5, 15, and 30 min, and at 1, 2, 3, 4, 5, 6, 7, and 8 h. A qualitative assessment of fill density using a 5-point scale was made for the stomach, small intestine, and ascending, transverse, and descending regions of the colon at each timepoint. Gastric emptying half-time occurred between 1 and 2 h postmeal. Mean fill density of the small intestine increased from 15 min postmeal and reached a peak at 3 h postmeal. Mean fill density of the proximal large intestine mirrored that of the small intestine. The distal large intestine remained empty for the first 2 h postmeal, then increased between hours 2 and 5 postmeal, and was subsequently at maximum fill density from hour 6 postmeal onwards. Fluoroscopic observation of a barium contrast meal provided an effective indication of the amount and progression of ingested food through the various regions of the gastrointestinal tract in habituated, fully conscious dogs. © 2016 American College of Veterinary Radiology.

  9. Dose assessments for SFR 1

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-06-15

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

  10. Dose assessments for SFR 1

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-06-15

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

  11. Radiological dose assessment for vault storage concepts

    Energy Technology Data Exchange (ETDEWEB)

    Richard, R.F.

    1997-02-25

    This radiological dose assessment presents neutron and photon dose rates in support of project W-460. Dose rates are provided for a single 3013 container, the ``infloor`` storage vault concept, and the ``cubicle`` storage vault concept.

  12. Dosimetry with a fluoroscopic electronic portal imaging device

    NARCIS (Netherlands)

    K.L. Pasma (Kasper)

    1999-01-01

    textabstractechniques for dosimetric verification of radiotherapy treatments using a CCD camera based fluoroscopic electronic portal imaging device (EPID) are described. The dosimetric characteristics of the EPID were investigated and a method was developed to derive portal dose images (PDIs) from m

  13. Irrigation in dose assessments models

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-05-01

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

  14. Estimates of diagnostic reference levels for pediatric peripheral and abdominal fluoroscopically guided procedures.

    Science.gov (United States)

    Strauss, Keith J; Racadio, John M; Johnson, Neil; Patel, Manish; Nachabe, Rami A

    2015-06-01

    The objective of our study was to survey radiation dose indexes of pediatric peripheral and abdominal fluoroscopically guided procedures from which estimates of diagnostic reference levels (DRLs) can be proposed for both a standard fluoroscope and a novel fluoroscope with advanced image processing and lower radiation dose rates. Radiation dose structured reports were retrospectively collected for 408 clinical pediatric cases: Half of the procedures were performed with a standard imaging technology and half with a novel x-ray technology. Dose-area product (DAP), air Kerma (AK), fluoroscopy time, number of digital subtraction angiography images, and patient mass were collected to calculate and normalize radiation dose indexes for procedures completed with the standard and novel fluoroscopes. The study population was composed of 180 and 175 patients who underwent procedures with the standard and novel technology, respectively. The 21 different types of pediatric peripheral and abdominal interventional procedures produced 408 total studies. Median ages, mass and body mass index, fluoroscopy time per procedure, and total number of recorded images for the standard and novel technologies were not statistically different. The area of the x-ray beams was square at the level of the patient with a dimension of 10-13 cm. The dose reduction achieved with the novel fluoroscope ranged from 18% to 51% of the dose required with the standard fluoroscope. The median DAP and AK patient dose indexes were 0.38 Gy · cm(2) and 4.00 mGy, respectively, for the novel fluoroscope. Estimates of dose indexes of pediatric peripheral and abdominal fluoroscopically guided, clinical procedures should assist in the development of DRLs to foster management of radiation doses of pediatric patients.

  15. Use of a graphics processing unit (GPU) to facilitate real-time 3D graphic presentation of the patient skin-dose distribution during fluoroscopic interventional procedures.

    Science.gov (United States)

    Rana, Vijay; Rudin, Stephen; Bednarek, Daniel R

    2012-02-23

    We have developed a dose-tracking system (DTS) that calculates the radiation dose to the patient's skin in real-time by acquiring exposure parameters and imaging-system-geometry from the digital bus on a Toshiba Infinix C-arm unit. The cumulative dose values are then displayed as a color map on an OpenGL-based 3D graphic of the patient for immediate feedback to the interventionalist. Determination of those elements on the surface of the patient 3D-graphic that intersect the beam and calculation of the dose for these elements in real time demands fast computation. Reducing the size of the elements results in more computation load on the computer processor and therefore a tradeoff occurs between the resolution of the patient graphic and the real-time performance of the DTS. The speed of the DTS for calculating dose to the skin is limited by the central processing unit (CPU) and can be improved by using the parallel processing power of a graphics processing unit (GPU). Here, we compare the performance speed of GPU-based DTS software to that of the current CPU-based software as a function of the resolution of the patient graphics. Results show a tremendous improvement in speed using the GPU. While an increase in the spatial resolution of the patient graphics resulted in slowing down the computational speed of the DTS on the CPU, the speed of the GPU-based DTS was hardly affected. This GPU-based DTS can be a powerful tool for providing accurate, real-time feedback about patient skin-dose to physicians while performing interventional procedures.

  16. Use of a graphics processing unit (GPU) to facilitate real-time 3D graphic presentation of the patient skin-dose distribution during fluoroscopic interventional procedures

    Science.gov (United States)

    Rana, Vijay; Rudin, Stephen; Bednarek, Daniel R.

    2012-03-01

    We have developed a dose-tracking system (DTS) that calculates the radiation dose to the patient's skin in realtime by acquiring exposure parameters and imaging-system-geometry from the digital bus on a Toshiba Infinix C-arm unit. The cumulative dose values are then displayed as a color map on an OpenGL-based 3D graphic of the patient for immediate feedback to the interventionalist. Determination of those elements on the surface of the patient 3D-graphic that intersect the beam and calculation of the dose for these elements in real time demands fast computation. Reducing the size of the elements results in more computation load on the computer processor and therefore a tradeoff occurs between the resolution of the patient graphic and the real-time performance of the DTS. The speed of the DTS for calculating dose to the skin is limited by the central processing unit (CPU) and can be improved by using the parallel processing power of a graphics processing unit (GPU). Here, we compare the performance speed of GPU-based DTS software to that of the current CPU-based software as a function of the resolution of the patient graphics. Results show a tremendous improvement in speed using the GPU. While an increase in the spatial resolution of the patient graphics resulted in slowing down the computational speed of the DTS on the CPU, the speed of the GPU-based DTS was hardly affected. This GPU-based DTS can be a powerful tool for providing accurate, real-time feedback about patient skin-dose to physicians while performing interventional procedures.

  17. Significance of including field non-uniformities such as the heel effect and beam scatter in the determination of the skin dose distribution during interventional fluoroscopic procedures

    Science.gov (United States)

    Rana, Vijay; Gill, Kamaljit; Rudin, Stephen; Bednarek, Daniel R.

    2012-03-01

    The current version of the real-time skin-dose-tracking system (DTS) we have developed assumes the exposure is contained within the collimated beam and is uniform except for inverse-square variation. This study investigates the significance of factors that contribute to beam non-uniformity such as the heel effect and backscatter from the patient to areas of the skin inside and outside the collimated beam. Dose-calibrated Gafchromic film (XR-RV3, ISP) was placed in the beam in the plane of the patient table at a position 15 cm tube-side of isocenter on a Toshiba Infinix C-Arm system. Separate exposures were made with the film in contact with a block of 20-cm solid water providing backscatter and with the film suspended in air without backscatter, both with and without the table in the beam. The film was scanned to obtain dose profiles and comparison of the profiles for the various conditions allowed a determination of field non-uniformity and backscatter contribution. With the solid-water phantom and with the collimator opened completely for the 20-cm mode, the dose profile decreased by about 40% on the anode side of the field. Backscatter falloff at the beam edge was about 10% from the center and extra-beam backscatter decreased slowly with distance from the field, being about 3% of the beam maximum at 6 cm from the edge. Determination of the magnitude of these factors will allow them to be included in the skin-dose-distribution calculation and should provide a more accurate determination of peak-skin dose for the DTS.

  18. Dose reduction technique using a combination of a region of interest (ROI) material x-ray attenuator and spatially different temporal filtering for fluoroscopic interventions

    Science.gov (United States)

    Swetadri Vasan, S. N.; Panse, A.; Jain, A.; Sharma, P.; Ionita, Ciprian N.; Titus, A. H.; Cartwright, A. N.; Bednarek, D. R.; Rudin, S.

    2012-03-01

    We demonstrate a novel approach for achieving patient dose savings during image-guided neurovascular interventions, involving a combination of a material x-ray region of interest (ROI) attenuator and a spatially different ROI temporal filtering technique. The part of the image under the attenuator is reduced in dose but noisy and less bright due to fewer x-ray quanta reaching the detector, as compared to the non-attenuating (or less attenuating) region. First the brightness is equalized throughout the image by post processing and then a temporal filter with higher weights is applied to the high attenuating region to reduce the noise, at the cost of increased lag; however, in the regions where less attenuation is present, a lower temporal weight is needed and is applied to preserve temporal resolution. A simulation of the technique is first presented on an actual image sequence obtained from an endovascular image guided interventional (EIGI) procedure. Then the actual implementation of the technique with a physical ROI attenuator is presented. Quantitative analysis including noise analysis and integral dose calculations are presented to validate the proposed technique.

  19. 4D cone beam CT-based dose assessment for SBRT lung cancer treatment

    Science.gov (United States)

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

    2016-01-01

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

  20. 3D delivered dose assessment using a 4DCT-based motion model

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-06-15

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

  1. Calculational Tool for Skin Contamination Dose Assessment

    CERN Document Server

    Hill, R L

    2002-01-01

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

  2. An updated dose assessment for Rongelap Island

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-07-01

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

  3. Assessment of the skin dose for aircrew.

    Science.gov (United States)

    Meier, Matthias M; Matthiä, Daniel

    2017-03-02

    Epidemiological studies are a useful instrument for investigating the influence of environmental factors on human health. In this context, the determination and quantification of the corresponding exposure is a demanding challenge. With regard to the investigation of the potential health effects in aircrew due to cosmic radiation, their occupational exposure at aviation altitudes is usually assessed in terms of the radiation protection quantity effective dose, which is stored in and available from official dose registers in many countries. However, when biological effects on a particular organ are investigated, knowledge of the corresponding exposure of that particular organ is necessary. In this study, we investigate the differences between the skin dose and the effective dose for the exposure of aircrew to cosmic radiation using a mathematical model for the radiation field at aviation altitudes. Furthermore, we present a method to deduce skin dose values from the officially registered effective doses.

  4. Assessing dose rate distributions in VMAT plans

    Science.gov (United States)

    Mackeprang, P.-H.; Volken, W.; Terribilini, D.; Frauchiger, D.; Zaugg, K.; Aebersold, D. M.; Fix, M. K.; Manser, P.

    2016-04-01

    Dose rate is an essential factor in radiobiology. As modern radiotherapy delivery techniques such as volumetric modulated arc therapy (VMAT) introduce dynamic modulation of the dose rate, it is important to assess the changes in dose rate. Both the rate of monitor units per minute (MU rate) and collimation are varied over the course of a fraction, leading to different dose rates in every voxel of the calculation volume at any point in time during dose delivery. Given the radiotherapy plan and machine specific limitations, a VMAT treatment plan can be split into arc sectors between Digital Imaging and Communications in Medicine control points (CPs) of constant and known MU rate. By calculating dose distributions in each of these arc sectors independently and multiplying them with the MU rate, the dose rate in every single voxel at every time point during the fraction can be calculated. Independently calculated and then summed dose distributions per arc sector were compared to the whole arc dose calculation for validation. Dose measurements and video analysis were performed to validate the calculated datasets. A clinical head and neck, cranial and liver case were analyzed using the tool developed. Measurement validation of synthetic test cases showed linac agreement to precalculated arc sector times within  ±0.4 s and doses  ±0.1 MU (one standard deviation). Two methods for the visualization of dose rate datasets were developed: the first method plots a two-dimensional (2D) histogram of the number of voxels receiving a given dose rate over the course of the arc treatment delivery. In similarity to treatment planning system display of dose, the second method displays the dose rate as color wash on top of the corresponding computed tomography image, allowing the user to scroll through the variation over time. Examining clinical cases showed dose rates spread over a continuous spectrum, with mean dose rates hardly exceeding 100 cGy min-1 for conventional

  5. ESR dose assessment in irradiated chicken legs

    Energy Technology Data Exchange (ETDEWEB)

    Bordi, F. [II Universita, Rome (Italy). Dipartimento di Medicina Interna; Fattibene, P.; Onori, S.; Pantaloni, M. [Istituto Superiore di Santia, Rome (Italy)]|[Istituto Nazionale di Fisica Nucleare, Rome (Italy). Sezione Sanita

    1994-05-01

    The electron spin resonance technique has received a wide consensus for dose assessment in irradiated chicken bone. Nevertheless, some practical problems are still open like the most suitable mathematical expression to be used for dose evaluation with the re-irradiation method. In the present paper the linear and exponential approximations were analyzed using 40 bone chicken samples and a reproducible readout procedure. The results suggested the use of the exponential dose-effect relationship and gave some indications on the procedure to be practically adopted. (author).

  6. Automated quantification of lumbar vertebral kinematics from dynamic fluoroscopic sequences

    Science.gov (United States)

    Camp, Jon; Zhao, Kristin; Morel, Etienne; White, Dan; Magnuson, Dixon; Gay, Ralph; An, Kai-Nan; Robb, Richard

    2009-02-01

    We hypothesize that the vertebra-to-vertebra patterns of spinal flexion and extension motion of persons with lower back pain will differ from those of persons who are pain-free. Thus, it is our goal to measure the motion of individual lumbar vertebrae noninvasively from dynamic fluoroscopic sequences. Two-dimensional normalized mutual information-based image registration was used to track frame-to-frame motion. Software was developed that required the operator to identify each vertebra on the first frame of the sequence using a four-point "caliper" placed at the posterior and anterior edges of the inferior and superior end plates of the target vertebrae. The program then resolved the individual motions of each vertebra independently throughout the entire sequence. To validate the technique, 6 cadaveric lumbar spine specimens were potted in polymethylmethacrylate and instrumented with optoelectric sensors. The specimens were then placed in a custom dynamic spine simulator and moved through flexion-extension cycles while kinematic data and fluoroscopic sequences were simultaneously acquired. We found strong correlation between the absolute flexionextension range of motion of each vertebra as recorded by the optoelectric system and as determined from the fluoroscopic sequence via registration. We conclude that this method is a viable way of noninvasively assessing twodimensional vertebral motion.

  7. Dose assessment of aircrew using passive detectors

    Energy Technology Data Exchange (ETDEWEB)

    Hajek, M.; Berge, T.; Schoener, W.; Summerer, L.; Vana, N

    2002-07-01

    Radiation exposure of aircrew is a serious concern which has been given special emphasis in the European Council directive 96/29/Euratom. The cosmic ray induced neutron component can contribute more than 50% to the biologically relevant dose at aviation altitudes. Various computational approaches to route dose assessment, e.g. CARI, are in use nowadays and are compared with experimental data. Measurements of aircrew exposure usually involve extensive instrumentation in order to cover the whole particle spectrum and energy range present inside aircraft. Due to their small size and easy handling, thermoluminescence dosemeters represent an appropriate alternative. Previous measurements onboard aircraft applying the high-temperature ratio method with LiF:Mg,Ti dosemeters for the determination of an 'averaged' linear energy transfer of mixed radiation fields demonstrate the ability of this method to evaluate the dose equivalent, according to the Q(LET{sub (}) relationship proposed by the ICRP. Measurements with CaF{sub 2}:Tm dosemeters are currently in progress and are discussed here. (author)

  8. Preliminary dose assessment of the Chernobyl accident

    Energy Technology Data Exchange (ETDEWEB)

    Hull, A.P.

    1987-01-01

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

  9. Assessment of internal doses in emergency situations

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-04-15

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

  10. Assessment of internal doses in emergency situations

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-04-15

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

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

    Science.gov (United States)

    Tselos, G D

    1995-11-01

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

  12. A feasibility study of markerless fluoroscopic gating for lung cancer radiotherapy using 4DCT templates

    Energy Technology Data Exchange (ETDEWEB)

    Li Ruijiang; Lewis, John H; Cervino, Laura I; Jiang, Steve B [Department of Radiation Oncology, University of California San Diego, 3855 Health Sciences Dr, La Jolla, CA 92037-0843 (United States)], E-mail: sbjiang@ucsd.edu

    2009-10-21

    A major difficulty in conformal lung cancer radiotherapy is respiratory organ motion, which may cause clinically significant targeting errors. Respiratory-gated radiotherapy allows for more precise delivery of prescribed radiation dose to the tumor, while minimizing normal tissue complications. Gating based on external surrogates is limited by its lack of accuracy, while gating based on implanted fiducial markers is limited primarily by the risk of pneumothorax due to marker implantation. Techniques for fluoroscopic gating without implanted fiducial markers (markerless gating) have been developed. These techniques usually require a training fluoroscopic image dataset with marked tumor positions in the images, which limits their clinical implementation. To remove this requirement, this study presents a markerless fluoroscopic gating algorithm based on 4DCT templates. To generate gating signals, we explored the application of three similarity measures or scores between fluoroscopic images and the reference 4DCT template: un-normalized cross-correlation (CC), normalized cross-correlation (NCC) and normalized mutual information (NMI), as well as average intensity (AI) of the region of interest (ROI) in the fluoroscopic images. Performance was evaluated using fluoroscopic and 4DCT data from three lung cancer patients. On average, gating based on CC achieves the highest treatment accuracy given the same efficiency, with a high target coverage (average between 91.9% and 98.6%) for a wide range of nominal duty cycles (20-50%). AI works well for two patients out of three, but failed for the third patient due to interference from the heart. Gating based on NCC and NMI usually failed below 50% nominal duty cycle. Based on this preliminary study with three patients, we found that the proposed CC-based gating algorithm can generate accurate and robust gating signals when using 4DCT reference template. However, this observation is based on results obtained from a very limited

  13. CANISTER HANDLING FACILITY WORKER DOSE ASSESSMENT

    Energy Technology Data Exchange (ETDEWEB)

    D.T. Dexheimer

    2004-02-27

    The purpose of this calculation is to estimate radiation doses received by personnel working in the Canister Handling Facility (CHF) performing operations to receive transportation casks, transfer wastes, prepare waste packages, perform associated equipment maintenance. The specific scope of work contained in this calculation covers individual worker group doses on an annual basis, and includes the contributions due to external and internal radiation. The results of this calculation will be used to support the design of the CHF and provide occupational dose estimates for the License Application.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-03-15

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

  15. Long term safety of fluoroscopically guided selective salpingography and tubal catheterization.

    Science.gov (United States)

    Papaioannou, S; Afnan, M; Coomarasamy, A; Ola, B; Hammadieh, N; Temperton, D H; McHugo, J M; Sharif, K

    2002-02-01

    The irradiation of the ovaries of reproductive age women during fluoroscopically guided selective salpingography and tubal catheterization has raised concern about the safety of the procedure. In addition to the risk of cancer induction, which exists with the irradiation of all tissues, with the gonads, the induction of hereditary disorders is possible. The objective of this study was to estimate these risks and present them in a clinically meaningful way. Retrospective analysis was undertaken of 366 consecutive cases of selective salpingography and tubal catheterization performed at the Birmingham Women's Hospital, UK. The radiation doses of different types of procedure were compared with the background annual radiation dose. The risks of cancer and genetic disorders induction were calculated using conversion coefficients published by the International Commission on Radiological Protection. The radiation dose women were exposed to during selective salpingography and tubal catheterization under fluoroscopic guidance was a fraction of the background annual radiation dose. The excess lifetime risks of cancer and hereditary disorders were in the order of four to 13 and two to six per million procedures respectively. The long term risks of selective salpingography and tubal catheterization under fluoroscopic guidance are low.

  16. An Internal Dose Assessment Associated with Personal Food Intake

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-10-15

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

  17. Dose assessment in the criticality accident at Tokai-mura

    Energy Technology Data Exchange (ETDEWEB)

    Endo, Akira, E-mail: endo.akira3@jaea.go.j [Japan Atomic Energy Agency, Tokai-mura, Ibaraki, 319-1195 (Japan)

    2010-12-15

    The present paper reviews a dose assessment carried out after the criticality accident that occurred on September 30, 1999 at JCO in Tokai-mura, Japan. In the accident, almost all doses were caused by external exposure to neutrons and {gamma}-rays emitted upon the fission of uranium. By a joint effort of Japanese experts in radiation dosimetry, a dose assessment was performed for neighboring residents, JCO employees including 3 workers who were at the accident spot, and emergency response personnel. The dose assessment was carried out using records of dosimeters, radiation monitoring data in and around the site, analysis of biological specimens, and computer simulation techniques. It was concluded from the results of the dose assessment that deterministic effects are not expected, except for the 3 heavily exposed workers, and that the probability of stochastic effects is very small and will be undetectable.

  18. Metrics, Dose, and Dose Concept: The Need for a Proper Dose Concept in the Risk Assessment of Nanoparticles

    Directory of Open Access Journals (Sweden)

    Myrtill Simkó

    2014-04-01

    Full Text Available In order to calculate the dose for nanoparticles (NP, (i relevant information about the dose metrics and (ii a proper dose concept are crucial. Since the appropriate metrics for NP toxicity are yet to be elaborated, a general dose calculation model for nanomaterials is not available. Here we propose how to develop a dose assessment model for NP in analogy to the radiation protection dose calculation, introducing the so-called “deposited and the equivalent dose”. As a dose metric we propose the total deposited NP surface area (SA, which has been shown frequently to determine toxicological responses e.g. of lung tissue. The deposited NP dose is proportional to the total surface area of deposited NP per tissue mass, and takes into account primary and agglomerated NP. By using several weighting factors the equivalent dose additionally takes into account various physico-chemical properties of the NP which are influencing the biological responses. These weighting factors consider the specific surface area, the surface textures, the zeta-potential as a measure for surface charge, the particle morphology such as the shape and the length-to-diameter ratio (aspect ratio, the band gap energy levels of metal and metal oxide NP, and the particle dissolution rate. Furthermore, we discuss how these weighting factors influence the equivalent dose of the deposited NP.

  19. Fluoroscopic image-guided intervention system for transbronchial localization

    Science.gov (United States)

    Rai, Lav; Keast, Thomas M.; Wibowo, Henky; Yu, Kun-Chang; Draper, Jeffrey W.; Gibbs, Jason D.

    2012-02-01

    Reliable transbronchial access of peripheral lung lesions is desirable for the diagnosis and potential treatment of lung cancer. This procedure can be difficult, however, because accessory devices (e.g., needle or forceps) cannot be reliably localized while deployed. We present a fluoroscopic image-guided intervention (IGI) system for tracking such bronchoscopic accessories. Fluoroscopy, an imaging technology currently utilized by many bronchoscopists, has a fundamental shortcoming - many lung lesions are invisible in its images. Our IGI system aligns a digitally reconstructed radiograph (DRR) defined from a pre-operative computed tomography (CT) scan with live fluoroscopic images. Radiopaque accessory devices are readily apparent in fluoroscopic video, while lesions lacking a fluoroscopic signature but identifiable in the CT scan are superimposed in the scene. The IGI system processing steps consist of: (1) calibrating the fluoroscopic imaging system; (2) registering the CT anatomy with its depiction in the fluoroscopic scene; (3) optical tracking to continually update the DRR and target positions as the fluoroscope is moved about the patient. The end result is a continuous correlation of the DRR and projected targets with the anatomy depicted in the live fluoroscopic video feed. Because both targets and bronchoscopic devices are readily apparent in arbitrary fluoroscopic orientations, multiplane guidance is straightforward. The system tracks in real-time with no computational lag. We have measured a mean projected tracking accuracy of 1.0 mm in a phantom and present results from an in vivo animal study.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-08-01

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

  1. Video-fluoroscopic study of swallowing in children with neurodevelopmental disorders.

    Science.gov (United States)

    Fung, Cheuk-Wing; Khong, Pek-Lan; To, Raymond; Goh, Winnie; Wong, Virginia

    2004-02-01

    Children with neurodevelopmental disorders can have feeding problems. Malnutrition and recurrent aspiration pneumonia can increase the risk of morbidity and mortality. Video-fluoroscopic study of swallowing (VFSS) is essential in understanding the pathological mechanisms involved during swallowing. The aim of the present study was to assess the role of VFSS in assessment and management of four children with various neurodevelopmental disorders in a multidisciplinary feeding team. We describe the team approach, with the participation of child neurologist, radiologist with the rehabilitation team including the speech therapist, occupational therapist and dietician, in the assessment and plan of management. Video-fluoroscopic study of swallowing had been useful in assessing the type of swallowing problems with treatment goals targeted to the basic underlying pathophysiological mechanism. A child neurologist should be involved in the multidisciplinary oromotor rehabilitation program for neurologically impaired children with feeding problems.

  2. Pediatric Percutaneous Osteoid Osteoma Ablation: Cone-Beam CT with Fluoroscopic Overlay Versus Conventional CT Guidance.

    Science.gov (United States)

    Perry, Brandon C; Monroe, Eric J; McKay, Tyler; Kanal, Kalpana M; Shivaram, Giridhar

    2017-05-11

    To compare technical success, clinical success, complications, radiation dose, and total room utilization time for osteoid osteoma thermal (radiofrequency or microwave) ablation using cone-beam computed tomography (CBCT) with two-axis fluoroscopic navigational overlay versus conventional computed tomography (CT) guidance. A retrospective review was performed to identify all osteoid osteoma ablations performed over a 5.5-year period at a single tertiary care pediatric hospital. Twenty-five ablations (15 radiofrequency and 10 microwave) in 23 patients undergoing fluoroscopic CBCT-guided osteoid osteoma ablation were compared to 35 ablations (35 radiofrequency) in 32 patients undergoing ablation via conventional CT guidance. Dose area product and dose length product were recorded for CBCT and conventional CT, respectively, and converted to effective doses. Technical success, clinical success (cessation of pain and medication use 1 month after ablation), complications, radiation dose, and total room utilization time were compared. All procedures were technically successful. Twenty-two of 25 (88.0%) CBCT and 31 of 35 (88.6%) conventional CT-guided ablations achieved immediate clinical success. There were two minor complications in each group and no major complications. Mean effective radiation dose was significantly lower for CBCT compared to CT guidance (0.12 vs. 0.39 mSv, p = 0.02). Mean total room utilization time for CBCT was longer (133.5 vs. 97.5 min, p = 0.0001). Fluoroscopic CBCT guidance for percutaneous osteoid osteoma ablation yields similar technical and clinical success, reduced radiation dose, and increased total room utilization time compared to conventional CT guidance.

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

    DEFF Research Database (Denmark)

    Kjellström, Tord; Grandjean, Philippe

    2007-01-01

    of the Toxic Effects of Metals Aluminum Antimony Arsenic Barium Beryllium Bismuth Cadmium Chromium Cobalt Copper Gallium and Semiconductor Compounds Germanium Indium Iron Lead Manganese Mercury Molybdenum Nickel Palladium Platinum Selenium Silver Tellurium Thallium Tin Titanium Tungsten Uranium Vanadium Zinc...... and their compounds. An entirely new structure and illustrations represent the vast array of advancements made since the last edition. Special emphasis has been placed on the toxic effects in humans with chapters on the diagnosis, treatment and prevention of metal poisoning. This up-to-date reference provides easy...... Selected Molecular Mechanisms of Metal Toxicity and Carcinogenicity General Considerations of Dose-Effect and Dose-Response Relationships Interactions in Metal Toxicology Epidemiological Methods for Assessing Dose-Response and Dose-Effect Relationships Essential Metals: Assessing Risks from Deficiency...

  4. Estradiol valerate and alcohol intake: dose-response assessments

    Science.gov (United States)

    Quirarte, Gina L; Reid, Larry D; de la Teja, I Sofía Ledesma; Reid, Meta L; Sánchez, Marco A; Díaz-Trujillo, Arnulfo; Aguilar-Vazquez, Azucena; Prado-Alcalá, Roberto A

    2007-01-01

    Background An injection of estradiol valerate (EV) provides estradiol for a prolonged period. Recent research indicates that a single 2.0 mg injection of EV modifies a female rat's appetite for alcoholic beverages. This research extends the initial research by assessing 8 doses of EV (from .001 to 2.0 mg/female rat), as well assessing the effects of 2.0 mg EV in females with ovariectomies. Results With the administration of EV, there was a dose-related loss of bodyweight reaching the maximum loss, when it occurred, at about 4 days after injections. Subsequently, rats returned to gaining weight regularly. Of the doses tested, only the 2.0 mg dose produced a consistent increase in intake of ethanol during the time previous research indicated that the rats would show enhanced intakes. There was, however, a dose-related trend for smaller doses to enhance intakes. Rats with ovariectomies showed a similar pattern of effects, to intact rats, with the 2 mg dose. After extensive histories of intake of alcohol, both placebo and EV-treated females had estradiol levels below the average measured in females without a history of alcohol-intake. Conclusion The data support the conclusion that pharmacological doses of estradiol can produce enduring changes that are manifest as an enhanced appetite for alcoholic beverages. The effect can occur among females without ovaries. PMID:17335585

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

    Energy Technology Data Exchange (ETDEWEB)

    Maldonado, Delis [Oak Ridge Institute for Science and Education, Oak Ridge, TN (United States). Independent Environmental Assessment and Verification Program

    2012-06-01

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

  6. Assessment of the dose distribution inside a cardiac cath lab using TLD measurements and Monte Carlo simulations

    Science.gov (United States)

    Baptista, M.; Teles, P.; Cardoso, G.; Vaz, P.

    2014-11-01

    Over the last decade, there was a substantial increase in the number of interventional cardiology procedures worldwide, and the corresponding ionizing radiation doses for both the medical staff and patients became a subject of concern. Interventional procedures in cardiology are normally very complex, resulting in long exposure times. Also, these interventions require the operator to work near the patient and, consequently, close to the primary X-ray beam. Moreover, due to the scattered radiation from the patient and the equipment, the medical staff is also exposed to a non-uniform radiation field that can lead to a significant exposure of sensitive body organs and tissues, such as the eye lens, the thyroid and the extremities. In order to better understand the spatial variation of the dose and dose rate distributions during an interventional cardiology procedure, the dose distribution around a C-arm fluoroscopic system, in operation in a cardiac cath lab at Portuguese Hospital, was estimated using both Monte Carlo (MC) simulations and dosimetric measurements. To model and simulate the cardiac cath lab, including the fluoroscopic equipment used to execute interventional procedures, the state-of-the-art MC radiation transport code MCNPX 2.7.0 was used. Subsequently, Thermo-Luminescent Detector (TLD) measurements were performed, in order to validate and support the simulation results obtained for the cath lab model. The preliminary results presented in this study reveal that the cardiac cath lab model was successfully validated, taking into account the good agreement between MC calculations and TLD measurements. The simulated results for the isodose curves related to the C-arm fluoroscopic system are also consistent with the dosimetric information provided by the equipment manufacturer (Siemens). The adequacy of the implemented computational model used to simulate complex procedures and map dose distributions around the operator and the medical staff is discussed, in

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-07-01

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

  8. Assessment of dose measurement uncertainty using RisøScan

    DEFF Research Database (Denmark)

    Helt-Hansen, J.; Miller, A.

    2006-01-01

    The dose measurement uncertainty of the dosimeter system RisoScan, office scanner and Riso B3 dosimeters has been assessed by comparison with spectrophotometer measurements of the same dosimeters. The reproducibility and the combined uncertainty were found to be approximately 2% and 4%, respectiv...

  9. A spatio-temporal detective quantum efficiency and its application to fluoroscopic systems

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, S. N.; Cunningham, I. A. [Sackler School of Medicine, Faculty of Medicine, Tel Aviv University, Ramat Aviv 69978 (Israel); Imaging Research Laboratories, Robarts Research Institute and Lawson Health Research Institute, 100 Perth Drive, London, Ontario N6A 5K8 (Canada) and Department of Medical Biophysics, University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B8 (Canada)

    2010-11-15

    Purpose: Fluoroscopic x-ray imaging systems are used extensively in spatio-temporal detection tasks and require a spatio-temporal description of system performance. No accepted metric exists that describes spatio-temporal fluoroscopic performance. The detective quantum efficiency (DQE) is a metric widely used in radiography to quantify system performance and as a surrogate measure of patient ''dose efficiency.'' It has been applied previously to fluoroscopic systems with the introduction of a temporal correction factor. However, the use of a temporally-corrected DQE does not provide system temporal information and it is only valid under specific conditions, many of which are not likely to be satisfied by suboptimal systems. The authors propose a spatio-temporal DQE that describes performance in both space and time and is applicable to all spatio-temporal quantum-based imaging systems. Methods: The authors define a spatio-temporal DQE (two spatial-frequency axes and one temporal-frequency axis) in terms of a small-signal spatio-temporal modulation transfer function (MTF) and spatio-temporal noise power spectrum (NPS). Measurements were made on an x-ray image intensifier-based bench-top system using continuous fluoroscopy with an RQA-5 beam at 3.9 {mu}R/frame and hardened 50 kVp beam (0.8 mm Cu filtration added) at 1.9 {mu}R/frame. Results: A zero-frequency DQE value of 0.64 was measured under both conditions. Nonideal performance was noted at both larger spatial and temporal frequencies; DQE values decreased by {approx}50% at the cutoff temporal frequency of 15 Hz. Conclusions: The spatio-temporal DQE enables measurements of decreased temporal system performance at larger temporal frequencies analogous to previous measurements of decreased (spatial) performance. This marks the first time that system performance and dose efficiency in both space and time have been measured on a fluoroscopic system using DQE and is the first step toward the

  10. A spatio-temporal detective quantum efficiency and its application to fluoroscopic systems.

    Science.gov (United States)

    Friedman, S N; Cunningham, I A

    2010-11-01

    Fluoroscopic x-ray imaging systems are used extensively in spatio-temporal detection tasks and require a spatio-temporal description of system performance. No accepted metric exists that describes spatio-temporal fluoroscopic performance. The detective quantum efficiency (DQE) is a metric widely used in radiography to quantify system performance and as a surrogate measure of patient "dose efficiency". It has been applied previously to fluoroscopic systems with the introduction of a temporal correction factor. However, the use of a temporally-corrected DQE does not provide system temporal information and it is only valid under specific conditions, many of which are not likely to be satisfied by suboptimal systems. The authors propose a spatio-temporal DQE that describes performance in both space and time and is applicable to all spatio-temporal quantum-based imaging systems. The authors define a spatio-temporal DQE (two spatial-frequency axes and one temporal-frequency axis) in terms of a small-signal spatio-temporal modulation transfer function (MTF) and spatio-temporal noise power spectrum (NPS). Measurements were made on an x-ray image intensifier-based bench-top system using continuous fluoroscopy with an RQA-5 beam at 3.9 microR/frame and hardened 50 kVp beam (0.8 mm Cu filtration added) at 1.9 microR/frame. A zero-frequency DQE value of 0.64 was measured under both conditions. Nonideal performance was noted at both larger spatial and temporal frequencies; DQE values decreased by approximately 50% at the cutoff temporal frequency of 15 Hz. The spatio-temporal DQE enables measurements of decreased temporal system performance at larger temporal frequencies analogous to previous measurements of decreased (spatial) performance. This marks the first time that system performance and dose efficiency in both space and time have been measured on a fluoroscopic system using DQE and is the first step toward the generalized use of DQE on clinical fluoroscopic systems.

  11. Radiological assessment. A textbook on environmental dose analysis

    Energy Technology Data Exchange (ETDEWEB)

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

    1983-09-01

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

  12. Dose estimates for the solid waste performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    Rittman, P.D.

    1994-08-30

    The Solid Waste Performance Assessment calculations by PNL in 1990 were redone to incorporate changes in methods and parameters since then. The ten scenarios found in their report were reduced to three, the Post-Drilling Resident, the Post-Excavation Resident, and an All Pathways Irrigator. In addition, estimates of population dose to people along the Columbia River are also included. The attached report describes the methods and parameters used in the calculations, and derives dose factors for each scenario. In addition, waste concentrations, ground water concentrations, and river water concentrations needed to reach the performance objectives of 100 mrem/yr and 500 person-rem/yr are computed. Internal dose factors from DOE-0071 were applied when computing internal dose. External dose rate factors came from the GENII Version 1.485 software package. Dose calculations were carried out on a spreadsheet. The calculations are described in detail in the report for 63 nuclides, including 5 not presently in the GENII libraries. The spreadsheet calculations were checked by comparison with GENII, as described in Appendix D.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-10-14

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

  14. Improvement of the following accident dose assessment system

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-12-15

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

  15. ASSESSMENT OF COLLECTIVE DOSE FOR TRAVELLERS BY WATERS

    Institute of Scientific and Technical Information of China (English)

    岳清宇; 姜萍; 等

    1995-01-01

    People travelling by air will receive more exposure dose and by water will receive less one.According to statistic data from the Ministry of Communications in 1988,the turnover in that year was about 2×1010 man.km.The total number of fishermen for inshore fishing was nearly two million reported by Ministry of Agriculture,Animal Husbandry and Fishery.Based on measured data on 212 points in six typical shipping lines of inshore lines and inland rivers,and the total voyage is 5625km,the average natural radiation dose rate received by travellers was calculated.From that assessment of collective effective dose for passengers by water and fishermen was derived.The value is 32.7man.Sv for passengers and 265.3man.Sv for fishermen.

  16. Development of fluoroscopic registration in spinal neuronavigation

    Science.gov (United States)

    Abbasi, Hamid R.; Grzeszczuk, Robert; Chin, Shao; Holz, H.; Hariri, Sanaz; Badr, Rana; Kim, Daniel; Adler, John R.; Shahidi, Ramin

    2001-05-01

    We present a system involving a computer-instrumented fluoroscope for the purpose of 3D navigation and guidance using pre-operative diagnostic scans as a reference. The goal of the project is to devise a computer-assisted tool that will improve the accuracy, reduce risk, minimize the invasiveness, and shorten the time it takes to perform a variety of neurosurgical and orthopedic procedures of the spine. For this purpose we propose an apparatus that will track surgical tools and localize them with respect to the patient's 3D anatomy and pre-operative 3D diagnostic scans using intraoperative fluoroscopy for in situ registration and localization of embedded fiducials. Preliminary studies have found a fiducial registration error (FRE) of 1.41 mm and a Target Localization Error (TLE) of 0.48 mm. The resulting system leverages equipment already commonly available in the operating room (OR), providing an important new functionality that is free of many current limitations, such as the inadequacy of skin fiducials for spinal neuronavigation, while keeping costs contained.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-05-01

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

  18. Methods of assessing total doses integrated across pathways

    Energy Technology Data Exchange (ETDEWEB)

    Grzechnik, M.; Camplin, W.; Clyne, F. [Centre for Environment, Fisheries and Aquaculture Science, Lowestoft (United Kingdom); Allott, R. [Environment Agency, London (United Kingdom); Webbe-Wood, D. [Food Standards Agency, London (United Kingdom)

    2006-07-01

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

  19. Percutaneous drainage of psoas abscess under real-time computed tomography fluoroscopic guidance

    Energy Technology Data Exchange (ETDEWEB)

    Yamagami, Takuji; Terayama, Koshi; Yoshimatsu, Rika; Matsumoto, Tomohiro; Miura, Hiroshi; Nishimura, Tsunehiko [Kyoto Prefectural University of Medicine, Department of Radiology, Graduate School of Medical Science, Kyoto (Japan)

    2009-03-15

    The goal of our study was to determine the usefulness of percutaneous abscess drainage under guidance of computed tomography (CT) fluoroscopy. Our subjects were 21 patients (seven women, 14 men; mean age 64 years; age range 30-87 years) who had undergone percutaneous drainage of 26 psoas abscess lesions under CT fluoroscopic guidance between May 2001 and January 2008. Drainage methods involved a needle puncture, insertion of a guidewire, serial dilations, and the exchange of the needle with a drainage tube. The procedures were guided by use of a helical CT scanner that provided real-time fluoroscopic reconstruction. Percutaneous drainage under real-time CT fluoroscopic guidance was successfully performed in every procedure. Use of real-time CT fluoroscopy allowed rapid assessment of needle, guidewire, and catheter placement. No patient had serious complications related to the drainage procedure. The mean procedure time required to drain one lesion was 35.6 {+-} 13.6 min. Mean period after the drainage procedure until complete disappearance of the abscess as confirmed by CT was 12.4 {+-} 10.0 days (range 3-46 days). CT fluoroscopy is useful in achieving accurate and safe drainage of abnormal psoas fluid collections. (orig.)

  20. Assessment of patient dose in medical processes by in-vivo dose measuring devices: A review

    Science.gov (United States)

    Tuncel, Nina

    2016-11-01

    In-vivo dosimetry (IVD) in medicine especially in radiation therapy is a well-established and recommended procedure for the estimation of the dose delivered to a patient during the radiation treatment. It became even more important with the emerging use of new and more complex radiotherapy techniques such as intensity-modulated or image-guided radiation therapy. While IVD has been used in brachytherapy for decades and the initial motivation for performing was mainly to assess doses to organs at risk by direct measurements, it is now possible to calculate 3D for detection of deviations or errors. In-vivo dosimeters can be divided into real-time and passive detectors that need some finite time following irradiation for their analysis. They require a calibration against a calibrated ionization chamber in a known radiation field. Most of these detectors have a response that is energy and/or dose rate dependent and consequently require adjustments of the response to account for changes in the actual radiation conditions compared to the calibration situation. Correction factors are therefore necessary to take. Today, the most common dosimeters for patients' dose verification through in-vivo measurements are semiconductor diodes, thermo-luminescent dosimeters, optically stimulated luminescence dosimeters, metal-oxide-semiconductor field-effect transistors and plastic scintillator detectors with small outer diameters.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-09-01

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

  2. Radiological environmental dose assessment methods and compliance dose results for 2015 operations at the savannah river site

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-09-01

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

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

    Science.gov (United States)

    Lofthag-Hansen, Sara

    2010-01-01

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

  4. Dose assessment associated with granite use in residential property

    Energy Technology Data Exchange (ETDEWEB)

    Leal, Andre Luiz do Carmo, E-mail: andre.leal@ifrj.edu.br [Instituto Federal do Rio de Janeiro (IFRJ), Sao Goncalo, RJ (Brazil); Lauria, Dejanira da Costa, E-mail: dejanira@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The radioactivity levels in materials used as building materials have been reported in many countries and relatively high levels of radioactivity have been identified in some materials build (Beretka and Mathew, 1985; Pavlidou et al., 2006; Tzortzis et al., 2003 ; Al-Selah and Al-Berzan, 2007; Kitto et al.,2009 ; Myatt et al., 2010 ). Although is reported in the literature some studies on the levels of radionuclides in granites and the associated doses (Salas, 2003; Ahmed et al., 2006; Bonotto et al, 2009 ; Turhan, 2012; Anjos et al., 2005, 2012), most of assessed dose are related with external exposure data (Anjos et al., 2011, Llope, 2011 ). From the radionuclide concentrations in 10 samples of granite rock, this study evaluated the dose by inhalation of radon from the use of national granites as floor covering, according to the refresh rate of air, porosity, and radon emanation rate of diffusion coefficient by sensitivity analyzes, using the RESRAD-BUILD 3.5 code. As a result, it was found that the higher dose by radon inhalation was 0.058 mSv / year and the Rn-220 isotope is the largest contributor to this route of exposure. (author)

  5. Improvement of the following accident dose assessment system (II)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Enn Han; Han, Moon Hee; Suh, Kyung Suk; Hwang, Won Tae; Choi, Young Gil [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2000-12-01

    The FADAS and its database have been updates for calculating the real-time wind fields continuously at the nuclear sites in Korea. The system has been constructed to compute the wind fields using its own process for the dummy meteorological data, and does not effect on the overall wind field module. If the radioactive materials are released into the atmosphere in real situation, the calculations of wind fields and exposure dose in the previous FADAS are performed in the case of the recognition of the above situation in the source term evaluation module. The current version of FADAS includes the program for evaluating the effect of the predicted accident and the assumed scenario together. The dose assessment module is separated into the real-time and the supposed accident respectively. 7 refs., 8 figs., 6 tabs. (Author)

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

    Science.gov (United States)

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

    2015-05-06

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-08-15

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

  8. A Study of Occupational Radiation Dosimetry During Fluoroscopically Guided Simulated Urological Surgery in the Lithotomy Position.

    Science.gov (United States)

    Horsburgh, Ben A; Higgins, Mike

    2016-12-01

    To quantify through environmental audit the radiation dose that urologists receive during surgery in the lithotomy position, and to quantify the dose reduction achieved by altering exposure techniques and personal protective equipment use. Simulated surgery in the lithotomy position using an anthropomorphic phantom as a patient and a SimMan(®) mannequin as the surgeon. Pulsed fluoroscopy, focus-to-skin distance (FSD), collimation, and addition of a lead shield at the table end were individually and collectively introduced after a control study. Scattered X-ray dose rates to the simulated surgeon's eye, thyroid, trunk, external genitalia, and leg were measured with each of the technique adjustments. The absorbed dose in air at the phantom skin was measured throughout. Results were compared to discover surgeon dose rates with technique alteration. Increasing FSD leads to a rise in surgeon eye dose, and table end lead protection increases the patient skin dose. Use of all the dose-reduction techniques together reduces the dose to the patient, and a surgeon's trunk dose is decreased by 95%, external genitalia dose by 99%, and leg dose by 97%. Sitting to perform fluoroscopically guided surgery in the lithotomy position increases surgeon dose by a median value of 17%, with the external genitalia dose increased by 78% compared with the standing position. This study describes effective methods of dose reduction that are easy to instigate. The resulting reduction in radiation dose during urology procedures meets the requirements of international guidelines and legislation. This change in practice improves patient care and reduces risk to urologists from occupational exposure to radiation. By combining all of the dose-reduction techniques, urologists should never reach the threshold for deterministic radiation effects to their eyes during their career, and they will have a significantly lower chance of stochastic risks such as cancer.

  9. Fluoroscopic studies of the upper gastrointestinal tract: techniques and indications.

    Science.gov (United States)

    Sánchez-Carpintero de la Vega, M; García Villar, C

    Fluoroscopic studies of the gastrointestinal tract are becoming increasing less common due to the introduction of other imaging techniques such as computed tomography and magnetic resonance imaging and to the increased availability of endoscopy. Nevertheless, fluoroscopic studies of the gastrointestinal tract continue to appear in clinical guidelines and some of their indications are still valid. These studies are dynamic, operator-dependent examinations that require training to obtain the maximum diagnostic performance. This review aims to describe the technique and bring the indications for this imaging modality up to date. Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  10. Heavy Metal Pad Shielding during Fluoroscopic Interventions

    OpenAIRE

    Dromi, Sergio; Wood, Bradford J.; Oberoi, Jay; Neeman, Ziv

    2006-01-01

    Significant direct and scatter radiation doses to patient and physician may result from routine interventional radiology practice. A lead-free disposable tungsten antimony shielding pad was tested in phantom patients during simulated diagnostic angiography procedures. Although the exact risk of low doses of ionizing radiation is unknown, dramatic dose reductions can be seen with routine use of this simple, sterile pad made from lightweighttungsten antimony material.

  11. Assessment of Patient Dose from CT Examinations in Khorasan, Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Taghi Bahreyni Toossi

    2013-03-01

    Full Text Available Introduction Computed Tomography scans are a very important tool for diagnosis and assessment of response to treatment in the practice of medicine. Ionizing radiation in medical imaging is undoubtedly one of the most powerful diagnostic tools in medicine. Yet, as with all medical interventions, there are potential risks in addition to the clear potential benefits. Materials and Methods Two reference dose quantities have been defined in order to promote the use of good technique in CT. These are weighted CT dose index (CTDIw in (mGy for a single slice in serial scanning or per rotation in helical scanning, and dose–length product (DLP per complete examination (mGy.cm, All measurements were performed using a pencil shaped ionization chamber introduced into polymethyl methacrylate cylindrical brain and body phantoms. This survey was performed on 7 CT scanners in Khorasan Province-Iran. Results DLP for brain, chest, abdomen and pelvic examinations had a range of 255 - 1026, 76-1277, 48-737, 69-854 mGy.cm, respectively. Conclusion The results obtained in this study show that the DLP values obtained in this province are lower than European Commission reference dose levels (EC RDL, in other words performance of all the scanners were satisfactory.

  12. Assessing medical students’ competence in calculating drug doses

    Directory of Open Access Journals (Sweden)

    Catherine Harries

    2013-09-01

    Full Text Available Evidence suggests that healthcare professionals are not optimally able to calculate medicine doses and various strategies have been employed to improve these skills. In this study, the performance of third and fourth year medical students was assessed and the success of various educational interventions investigated. Students were given four types of dosing calculations typical of those required in an emergency setting. Full competence (at the 100% level was defined as correctly answering all four categories of calculation at any one time. Three categories correct meant competence at the 75% level. Interventions comprised an assignment with a model answer for self-assessment in the third year and a small group tutorial in the fourth year. The small groups provided opportunities for peer-assisted learning. A subgroup of 23 students received individual tuition from the lecturer prior to the start of the fourth year. Amongst the 364 eligible students, full competence rose from 23% at the beginning of the third year to 66% by the end of the fourth year. More students succeeded during the fourth than the third year of study. Success of small group tuition was assessed in a sample of 200 students who had formal assessments both before and after the fourth year tuition. Competence at the 75% level improved by 10% in attendees and decreased by 3% in non-attendees, providing evidence of the value of students receiving assistance from more able same-language peers. Good results were achieved with one-on-one tuition where individualised assistance allowed even struggling students to improve.

  13. Multimodality calibration for simultaneous fluoroscopic and nuclear imaging

    NARCIS (Netherlands)

    Beijst, Casper; Elschot, Mattijs; van der Velden, Sanda; de Jong, Hugo W A M

    2016-01-01

    BACKGROUND: Simultaneous real-time fluoroscopic and nuclear imaging could benefit image-guided (oncological) procedures. To this end, a hybrid modality is currently being developed by our group, by combining a c-arm with a gamma camera and a four-pinhole collimator. Accurate determination of the sys

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1983-05-01

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

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

    Directory of Open Access Journals (Sweden)

    I. P. Stamat

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Davis, W.E.; Schmidt, J.W.; Gleckler, B.P. [Westinghouse Hanford Co., Richland, WA (United States); Rhoads, K. [Pacific Northwest Lab., Richland, WA (United States)

    1995-01-01

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

  17. Non-fluoroscopic navigation systems for radiofrequency catheter ablation for supraventricular tachycardia reduce ionising radiation exposure.

    Science.gov (United States)

    See, Jason; Amora, Jonah L; Lee, Sheldon; Lim, Paul; Teo, Wee Siong; Tan, Boon Yew; Ho, Kah Leng; Lee, Chee Wan; Ching, Chi-Keong

    2016-07-01

    The use of non-fluoroscopic systems (NFS) to guide radiofrequency catheter ablation (RFCA) for the treatment of supraventricular tachycardia (SVT) is associated with lower radiation exposure. This study aimed to determine if NFS reduces fluoroscopy time, radiation dose and procedure time. We prospectively enrolled patients undergoing RFCA for SVT. NFS included EnSiteTM NavXTM or CARTO® mapping. We compared procedure and fluoroscopy times, and radiation exposure between NFS and conventional fluoroscopy (CF) cohorts. Procedural success, complications and one-year success rates were reported. A total of 200 patients over 27 months were included and RFCA was guided by NFS for 79 patients; those with atrioventricular nodal reentrant tachycardia (AVNRT), left-sided atrioventricular reentrant tachycardia (AVRT) and right-sided AVRT were included (n = 101, 63 and 36, respectively). Fluoroscopy times were significantly lower with NFS than with CF (10.8 ± 11.1 minutes vs. 32.0 ± 27.5 minutes; p < 0.001). The mean fluoroscopic dose area product was also significantly reduced with NFS (NSF: 5,382 ± 5,768 mGy*cm2 vs. CF: 21,070 ± 23,311 mGy*cm2; p < 0.001); for all SVT subtypes. There was no significant reduction in procedure time, except for left-sided AVRT ablation (NFS: 79.2 minutes vs. CF: 116.4 minutes; p = 0.001). Procedural success rates were comparable (NFS: 97.5% vs. CF: 98.3%) and at one-year follow-up, there was no significant difference in the recurrence rates (NFS: 5.2% vs. CF: 4.2%). No clinically significant complications were observed in both groups. The use of NFS for RFCA for SVT is safe, with significantly reduced radiation dose and fluoroscopy time. Copyright © Singapore Medical Association.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-10-03

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

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

    Science.gov (United States)

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

    2010-05-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-12-01

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

  1. Ulcerated Radiodermatitis Induced after Fluoroscopically Guided Stent Implantation Angioplasty

    Science.gov (United States)

    Herz-Ruelas, Maira Elizabeth; Gómez-Flores, Minerva; Moxica-del Angel, Joaquín; Miranda-Maldonado, Ivett; Gutiérrez-Villarreal, Ilse Marilú; Villarreal-Rodríguez, Adriana Orelia

    2014-01-01

    Cases of radiation-induced skin injury after fluoroscopically guided procedures have been reported since 1996, though the majority of them have been published in Radiology and Cardiology literature, less frequently in Dermatology journals. Chronic radiation dermatitis induced by fluoroscopy can be difficult to diagnose; a high grade of suspicion is required. We report a case of an obese 46-year-old man with hypertension, dyslipidemia, and severe coronary artery disease. He developed a pruritic and painful atrophic ulcerated skin plaque over his left scapula, six months after fluoroscopically guided stent implantation angioplasty. The diagnosis of radiodermatitis was confirmed histologically. We report this case to emphasize the importance of recognizing fluoroscopy as a cause of radiation dermatitis. A good clinical follow-up at regular intervals is important after long and complicated procedures, since the most prevalent factor for injury is long exposure time. PMID:25276441

  2. Ulcerated Radiodermatitis Induced after Fluoroscopically Guided Stent Implantation Angioplasty

    Directory of Open Access Journals (Sweden)

    Maira Elizabeth Herz-Ruelas

    2014-01-01

    Full Text Available Cases of radiation-induced skin injury after fluoroscopically guided procedures have been reported since 1996, though the majority of them have been published in Radiology and Cardiology literature, less frequently in Dermatology journals. Chronic radiation dermatitis induced by fluoroscopy can be difficult to diagnose; a high grade of suspicion is required. We report a case of an obese 46-year-old man with hypertension, dyslipidemia, and severe coronary artery disease. He developed a pruritic and painful atrophic ulcerated skin plaque over his left scapula, six months after fluoroscopically guided stent implantation angioplasty. The diagnosis of radiodermatitis was confirmed histologically. We report this case to emphasize the importance of recognizing fluoroscopy as a cause of radiation dermatitis. A good clinical follow-up at regular intervals is important after long and complicated procedures, since the most prevalent factor for injury is long exposure time.

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

    Energy Technology Data Exchange (ETDEWEB)

    Rampado, Osvaldo, E-mail: orampado@cittadellasalute.to.it; Giglioli, Francesca Romana; Rossetti, Veronica; Ropolo, Roberto [Struttura Complessa Fisica Sanitaria, Azienda Ospedaliero Universitaria Città della Salute e della Scienza, Corso Bramante 88, Torino 10126 (Italy); Fiandra, Christian; Ragona, Riccardo [Radiation Oncology Department, University of Turin, Torino 10126 (Italy)

    2016-05-15

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

  4. Cyclic voiding cystouretrography without the use of fluoroscopic monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Kadioglu, Alev [ALKA Medical Imaging Center, Buyukdere Cad. Levent Apt. No: 36/16, 80200-Mecidiyekoy, Istanbul (Turkey)]. E-mail: alevkadioglu@yahoo.com; Mihmanli, Ismail [Istanbul University, Cerrahpasa Medical Faculty, Department of Radiology, 34300-Istanbul (Turkey); Kantarci, Fatih [Istanbul University, Cerrahpasa Medical Faculty, Department of Radiology, 34300-Istanbul (Turkey); Tekes, Aylin [ALKA Medical Imaging Center, Buyukdere Cad. Levent Apt. No: 36/16, 80200-Mecidiyekoy, Istanbul (Turkey); Uysal, Omer [Istanbul University, Cerrahpasa Medical Faculty, Department of Biostatistics, 34300-Istanbul (Turkey)

    2006-01-15

    Purpose: To determine whether cyclic voiding cystourethrography (VCUG) examinations can be performed without using real-time fluoroscopic monitoring. Materials and methods: VCUG examinations were performed in 209 children (133 girls and 76 boys). In each child, it was performed in a cyclic manner (three consecutive cycles) without using fluoroscopic monitoring and one radiograph was taken in each cycle of the examination. All patients were sedated by midazolam prior to examination. The degree of vesicoureteric reflux (VUR) was graded for each of the kidney ureter units (KUU) (total 418 KUU) separately. Statistical analysis included the comparison of the presence and absence of VUR and three ordinal-matched comparisons of each cycle. Results: VCUG was detected in 37.3% of the children (78/209) and 28.7% (120/418) of the KUU. The absence of or same degree of VUR in three consecutive cycles were obtained in 345 KUU and the agreement was calculated as 82.5%. The same degree and presence of reflux were found in 85 and 89 refluxing KUU, the same negative findings (absence of VUR) in 306 and 298 KUU, and discordant findings in 27 and 31 KUU (between the first and second and between first and third cycles), respectively. Therefore, the agreement was 93.5 and 92.5% between the first and second cycles (p = 0.70) and between the first and the third cycles (p = 0.15), respectively. Conclusion: Both the cyclic nature of this study and the results indicated that VCUG without real-time fluoroscopic monitoring could be used where adequate fluoroscopic examination is not possible for children in whom VUR detection is necessary and impacts treatment. However, the responsibility of pediatric radiologist always must also include the task to provide proper equipment for imaging children with suspected VUR.

  5. Vaginal dose assessment in image-guided brachytherapy for cervical cancer: Can we really rely on dose-point evaluation?

    Science.gov (United States)

    Limkin, Elaine Johanna; Dumas, Isabelle; Rivin Del Campo, Eleonor; Chargari, Cyrus; Maroun, Pierre; Annède, Pierre; Petit, Claire; Seisen, Thomas; Doyeux, Kaya; Tailleur, Anne; Martinetti, Florent; Lefkopoulos, Dimitri; Haie-Meder, Christine; Mazeron, Renaud

    2016-01-01

    Although dose-volume parameters in image-guided brachytherapy have become a standard, the use of posterior-inferior border of the pubic symphysis (PIBS) points has been recently proposed in the reporting of vaginal doses. The aim was to evaluate their pertinence. Nineteen patients who received image-guided brachytherapy after concurrent radiochemotherapy were included. Per treatment, CT scans were performed at Days 2 and 3, with reporting of the initial dwell positions and times. Doses delivered to the PIBS points were evaluated on each plan, considering that they were representative of one-third of the treatment. The movements of the applicator according to the PIBS point were analysed. Mean prescribed doses at PIBS -2, PIBS, PIBS +2 were, respectively, 2.23 ± 1.4, 6.39 ± 6.6, and 31.85 ± 36.06 Gy. Significant differences were observed between the 5 patients with vaginal involvement and the remaining 14 at the level of PIBS +2 and PIBS: +47.60 Gy and +7.46 Gy, respectively (p = 0.023 and 0.03). The variations between delivered and prescribed doses at PIBS points were not significant. However, at International commission on radiation units and measurements rectovaginal point, the delivered dose was decreased by 1.43 ± 2.49 Gy from the planned dose (p = 0.019). The delivered doses at the four points were strongly correlated with the prescribed doses with R(2) ranging from 0.93 to 0.95. The movements of the applicator in regard of the PIBS point assessed with the Digital Imaging and Communications in Medicine coordinates were insignificant. The doses evaluated at PIBS points are not impacted by intrafractional movements. PIBS and PIBS +2 dose points allow distinguishing the plans of patients with vaginal infiltration. Further studies are needed to correlate these parameters with vaginal morbidity. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    Vilarinho, Luisa Maria Auredine Lima

    2004-07-01

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

  7. Dose assessment intercomparisons within the RENEB network using G0-lymphocyte prematurely condensed chromosomes (PCC assay)

    OpenAIRE

    Terzoudi, Georgia I; Pantelias, Gabriel; Darroudi, Firouz; Barszczewska, Katarzyna; Buraczewska, Iwona; Depuydt, Julie; Georgieva, Dimka; Hadjidekova, Valeria; Hatzi, Vasiliki I.; Karachristou, Ioanna; Karakosta, Maria; Meschini, Roberta; M’kacher, Radhia; Montoro, Alegria; Palitti, Fabrizio

    2017-01-01

    Purpose: Dose assessment intercomparisons within the RENEB network were performed for triage biodosimetry analyzing G0-lymphocyte PCC for harmonization, standardization and optimization of the PCC assay. Materials and methods: Comparative analysis among different partners for dose assessment included shipment of PCC-slides and captured images to construct dose-response curves for up to 6 Gy c-rays. Accident simulation exercises were performed to assess the suitability of the PCC assay by d...

  8. KREAM: Korean Radiation Exposure Assessment Model for Aviation Route Dose

    Science.gov (United States)

    Hwang, J.; Dokgo, K.; Choi, E. J.; Kim, K. C.; Kim, H. P.; Cho, K. S. F.

    2014-12-01

    Since Korean Air has begun to use the polar route from Seoul/ICN airport to New York/JFK airport on August 2006, there are explosive needs for the estimation and prediction against cosmic radiation exposure for Korean aircrew and passengers in South Korea from public. To keep pace with those needs of public, Korean government made the law on safety standards and managements of cosmic radiation for the flight attendants and the pilots in 2013. And we have begun to develop our own Korean Radiation Exposure Assessment Model (KREAM) for aviation route dose since last year funded by Korea Meteorological Administration (KMA). GEANT4 model and NRLMSIS 00 model are used for calculation of the energetic particles' transport in the atmosphere and for obtaining the background atmospheric neutral densities depending on altitude. For prediction the radiation exposure in many routes depending on the various space weather effects, we constructed a database from pre-arranged simulations using all possible combinations of R, S, and G, which are the space weather effect scales provided by the National Oceanic and Atmospheric Administration (NOAA). To get the solar energetic particles' spectrum at the 100 km altitude which we set as a top of the atmospheric layers in the KREAM, we use ACE and GOES satellites' proton flux observations. We compare the results between KREAM and the other cosmic radiation estimation programs such as CARI-6M which is provided by the Federal Aviation Agency (FAA). We also validate KREAM's results by comparison with the measurement from Liulin-6K LET spectrometer onboard Korean commercial flights and Korean Air Force reconnaissance flights.

  9. Toxicity from repeated doses of acetaminophen in children: assessment of causality and dose in reported cases.

    Science.gov (United States)

    Heard, Kennon; Bui, Alison; Mlynarchek, Sara L; Green, Jody L; Bond, G Randall; Clark, Richard F; Kozer, Eran; Koff, Raymond S; Dart, Richard C

    2014-01-01

    Liver injury has been reported in children treated with repeated doses of acetaminophen. The objective of this study was to identify and validate reports of liver injury or death in children younger than 6 years who were administered repeated therapeutic doses of acetaminophen. We reviewed US Poison Center data, peer-reviewed literature, US Food and Drug Administration Adverse Event Reports, and US Manufacturer Safety Reports describing adverse effects after acetaminophen administration. Reports that described hepatic abnormalities (description of liver injury or abnormal laboratory testing) or death after acetaminophen administration to children younger than 6 years were included. The identified reports were double abstracted and then reviewed by an expert panel to determine if the hepatic injury was related to acetaminophen and whether the dose of acetaminophen was therapeutic (≤75 mg/kg) or supratherapeutic. Our search yielded 2531 reports of adverse events associated with acetaminophen use. From these cases, we identified 76 cases of hepatic injury and 26 deaths associated with repeated acetaminophen administration. There were 6 cases of hepatic abnormalities and no deaths associated with what our panel determined to be therapeutic doses. A large proportion of cases could not be fully evaluated due to incomplete case reporting. Although we identified numerous examples of liver injury and death after repeated doses of acetaminophen, all the deaths and all but 6 cases of hepatic abnormalities involved doses more than 75 mg/kg per day. This study suggests that the doses of less than 75 mg/kg per day of acetaminophen are safe for children younger than 6 years.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-12-01

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

  11. Radiation Dose-Response Relationships and Risk Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Strom, Daniel J.

    2005-07-05

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

  12. Radiation dose assessment of ACP hot cell in accident

    Energy Technology Data Exchange (ETDEWEB)

    Kook, D. H.; Jeong, W. M.; Koo, J. H.; Jeo, I. J.; Lee, E. P.; Ryu, K. S. [KAERI, Taejon (Korea, Republic of)

    2003-10-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-05-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1981-09-01

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

  15. Dose assessment of an accidental exposure at the IPNS

    Energy Technology Data Exchange (ETDEWEB)

    Campos Torres, M.M.

    1995-02-01

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

  16. Dose assessment of an accidental exposure at IPNS

    Energy Technology Data Exchange (ETDEWEB)

    Torres, M.M.C.

    1996-05-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

  18. Fetal and maternal dose assessment for diagnostic scans during pregnancy

    Science.gov (United States)

    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.

  19. Dose assessment in accordance with the measured position of size specific dose estimates

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Su [Dept. of Radio-technology, Health Welfare, Wonkwang Health Science University, Iksan (Korea, Republic of); Hong, Sung Wan [Dept. of Radiology, Inje University Ilsan Paik Hospital, Iksan (Korea, Republic of); Kim, Jung Min [Dept. of Radiological Science, Korea University, Seoul (Korea, Republic of)

    2015-12-15

    This study investigated the size specific dose estimates of difference localizer on pediatric CT image. Seventy one cases of pediatric abdomen-pelvic CT (M:F=36:35) were included in this study. Anterior-posterior and lateral diameters were measured in axial CT images. Conversion factors from American Association of Physicists in Medicine (AAPM) report 204 were obtained for effective diameter to determine size specific dose estimate (SSDE) from the CT dose index volume (CTDIvol) recorded from the dose reports. For the localizer of mid-slice SSDE was 107.63% higher than CTDIvol and that of xiphoid-process slices SSDE was higher than 92.91%. The maximum error of iliac crest slices, xiphoid process slices and femur head slices between mid-slices were 7.48%, 17.81% and 14.04%. In conclusion, despite the SSDE of difference localizer has large number of errors, SSDE should be regarded as the primary evaluation tool of the patient radiation in pediatric CT for evaluation.

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

    Science.gov (United States)

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

    2012-06-01

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

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

    Science.gov (United States)

    Hanlon, Justin Mitchell

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

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

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2017-05-01

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

  3. Assessment of patient and occupational dose in established and new applications of MDCT fluoroscopy.

    Science.gov (United States)

    Joemai, Raoul M S; Zweers, Dirk; Obermann, Wim R; Geleijns, Jacob

    2009-04-01

    This study aimed to assess patient dose and occupational dose in established and new applications of MDCT fluoroscopy. Electronic personal dosimeters were used to measure occupational dose equivalent. Effective patient dose was derived from the recorded dose-length product. Acquisition parameters that were observed during CT fluoroscopy (CTF) provided the basis for the estimation of an entrance skin dose profile. Two hundred ten CT-guided interventional procedures were included in the study. The median effective patient dose was 10 mSv (range, 0.1-235 mSv; 107 procedures). The median peak entrance skin dose was 0.4 Sv (0.1-2.1 Sv; 27 procedures). From 547 measurements of occupational dose equivalent, a median occupational effective dose of 3 muSv per procedure was derived for the interventional radiologists and 0.4 muSv per procedure for the assisting radiologists and radiology technologists. The estimated maximum occupational effective dose reached 0.4 mSv. The study revealed high effective patient doses, up to 235 mSv, mainly for relatively new applications such as CTF-guided radiofrequency ablations using MDCT, vertebroplasty, and percutaneous ethanol injections of tumors. Entrance doses were occasionally in the range of the warning level for deterministic skin effects but were always below the threshold for serious deterministic effects. The complexity of the procedure, expected benefits of the treatment, and general health state of the patient contribute to the justification of observed high effective patient doses.

  4. Intrapelvic obturator internus muscle injections: a novel fluoroscopic technique.

    Science.gov (United States)

    Valovska, Assia; Zaccagnino, Michael P; Weaver, Michael J; Valovski, Ivan; Kaye, Alan David; Urman, Richard D

    2015-01-01

    The obturator internus (OI) muscle is important in adult chronic noninfectious pelvic, perineal, gluteal, and retrotrochanteric pain syndromes. Evaluation and management of these patients' pain can be challenging because of the complex anatomy of this region, broad differential diagnosis, and lack of specific physical examination findings. Consequently, several clinicians have advocated the use of image guided injections to assist in the accurate diagnosis of OI-related symptoms and provide symptomatic relief to affected patients. We present 2 case series describing a novel fluoroscopically guided contrast controlled transpectineal approach to intrapelvic OI injections. Unlike prior fluoroscopically guided OI injection techniques, the approach described in the present 2 cases utilized multiple standard pelvic views, thus facilitating optimal needle positioning in three-dimensional space. This technique utilized standard fluoroscopic pelvic views to accurately measure needle depth within the pelvic cavity permitting the bulk of the OI to be injected in a controlled and safe fashion. The first patient underwent a left intrapelvic OI muscle injection with bupivacaine 0.25% and 40 mg methylprednisolone. The average pre- and postprocedural visual analog pain scale scores were 5 out of 10 and 2 out of 10, respectively, with a self-reported 75% pain reduction. The second patient underwent a right intrapelvic OI muscle injection with bupivacaine 0.25% and 40 mg methylprednisolone. The average pre- and postprocedural visual analog scale scores were 8 out of 10 and 1 out of 10, respectively, with a self-reported 90% pain reduction. Larger scale studies should be undertaken to evaluate the therapeutic efficacy and generalized accuracy of this technique.

  5. Multimodality calibration for simultaneous fluoroscopic and nuclear imaging

    OpenAIRE

    Beijst, Casper; Elschot, Mattijs; van der Velden, Sandra; de Jong, Hugo W A M

    2016-01-01

    Background Simultaneous real-time fluoroscopic and nuclear imaging could benefit image-guided (oncological) procedures. To this end, a hybrid modality is currently being developed by our group, by combining a c-arm with a gamma camera and a four-pinhole collimator. Accurate determination of the system parameters that describe the position of the x-ray tube, x-ray detector, gamma camera, and collimators is crucial to optimize image quality. The purpose of this study was to develop a calibratio...

  6. Dose-response modeling : Evaluation, application, and development of procedures for benchmark dose analysis in health risk assessment of chemical substances

    OpenAIRE

    Sand, Salomon

    2005-01-01

    In this thesis, dose-response modeling and procedures for benchmark dose (BMD) analysis in health risk assessment of chemical substances have been investigated. The BMD method has been proposed as an alternative to the NOAEL (no-observedadverse- effect-level) approach in health risk assessment of non-genotoxic agents. According to the BMD concept, a dose-response model is fitted to data and the BMD is defined as the dose causing a predetermined change in response. A lowe...

  7. Retrospective study on the dose assessment in Algeria over a period 1998-2002

    Energy Technology Data Exchange (ETDEWEB)

    Boudena, B.; Chalal, M.; Bellal, A.; Imatoukene, D. [Nuclear Research Center of Algiers (Algeria)

    2006-07-01

    Full text: In Algeria, the assessment of individual doses of workers occupationally exposed to external radiations is made by the national individual monitoring service at the Nuclear Research Center of Algiers (N.R.C.A.) with photographic dosimeter. In this paper, we have undertaken a retrospective study on dose assessment of workers exposed to external radiations involved in medical and industrial activities according to the new occupational dose limits over a period of five consecutive years (1998 2002). This survey has permitted to observe the impact that would have new dose limits once adopted by our legislation. (author)

  8. Radon dose assessment in underground mines in Brazil.

    Science.gov (United States)

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

    2014-07-01

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

  9. Assessment and interpretation of internal doses: uncertainty and variability.

    Science.gov (United States)

    Paquet, F; Bailey, M R; Leggett, R W; Harrison, J D

    2016-06-01

    Internal doses are calculated on the basis of knowledge of intakes and/or measurements of activity in bioassay samples, typically using reference biokinetic and dosimetric models recommended by the International Commission on Radiological Protection (ICRP). These models describe the behaviour of the radionuclides after ingestion, inhalation, and absorption to the blood, and the absorption of the energy resulting from their nuclear transformations. They are intended to be used mainly for the purpose of radiological protection: that is, optimisation and demonstration of compliance with dose limits. These models and parameter values are fixed by convention and are not subject to uncertainty. Over the past few years, ICRP has devoted a considerable amount of effort to the revision and improvement of models to make them more physiologically realistic. ICRP models are now sufficiently sophisticated for calculating organ and tissue absorbed doses for scientific purposes, and in many other areas, including toxicology, pharmacology and medicine. In these specific cases, uncertainties in parameters and variability between individuals need to be taken into account.

  10. Variability of a peripheral dose among various linac geometries for second cancer risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Joosten, A; Bochud, F; Baechler, S; Moeckli, R [University Institute for Radiation Physics, CHUV and University of Lausanne, Grand-Pre 1, CH-1007 Lausanne (Switzerland); Levi, F [Cancer Epidemiology Unit and Cancer Registries of Vaud and Neuchatel, Institute of Social and Preventive Medecine (IUMSP) and University of Lausanne, CHUV-Falaises 1, CH-1011 Lausanne (Switzerland); Mirimanoff, R-O, E-mail: raphael.moeckli@chuv.ch [Radio-Oncology Department, CHUV and University of Lausanne, Bugnon 21, CH-1011 Lausanne (Switzerland)

    2011-08-21

    Second cancer risk assessment for radiotherapy is controversial due to the large uncertainties of the dose-response relationship. This could be improved by a better assessment of the peripheral doses to healthy organs in future epidemiological studies. In this framework, we developed a simple Monte Carlo (MC) model of the Siemens Primus 6 MV linac for both open and wedged fields that we then validated with dose profiles measured in a water tank up to 30 cm from the central axis. The differences between the measured and calculated doses were comparable to other more complex MC models and never exceeded 50%. We then compared our simple MC model with the peripheral dose profiles of five different linacs with different collimation systems. We found that the peripheral dose between two linacs could differ up to a factor of 9 for small fields (5 x 5 cm{sup 2}) and up to a factor of 10 for wedged fields. Considering that an uncertainty of 50% in dose estimation could be acceptable in the context of risk assessment, the MC model can be used as a generic model for large open fields ({>=}10 x 10 cm{sup 2}) only. The uncertainties in peripheral doses should be considered in future epidemiological studies when designing the width of the dose bins to stratify the risk as a function of the dose.

  11. A prospective evaluation of complications of 10,000 fluoroscopically directed epidural injections.

    Science.gov (United States)

    Manchikanti, Laxmaiah; Malla, Yogesh; Wargo, Bradley W; Cash, Kimberly A; Pampati, Vidyasagar; Fellows, Bert

    2012-01-01

    Among the multiple modalities of treatments available in managing chronic spinal pain, including surgery and multiple interventional techniques, epidural injections by various routes, such as interlaminar epidural injections, caudal epidural injections, transforaminal epidural injections, and percutaneous adhesiolysis are common. Even though the complications of fluoroscopically directed epidural injections are fewer than blind epidural injections, and have better effectiveness, multiple complications have been reported in scattered case reports, with only minor complications in randomized or non-randomized studies and systematic reviews. Thus, prospective studies with large patient series are essential to determine the types and incidences of complications. A prospective, non-randomized study of patients undergoing interventional techniques from May 2008 to December 2009. A private interventional pain management practice, a specialty referral center in the United States. To assess the complication rate of fluoroscopically directed epidural injections. This study was carried out over a period of 20 months and included over 10,000 procedures: 39% caudal epidurals, 23% cervical interlaminar epidurals, 14% lumbar interlaminar epidurals, 13% lumbar transforaminal epidurals, 8% percutaneous adhesiolysis, and 3% thoracic interlaminar epidural procedures. All of the interventions were performed under fluoroscopic guidance in an ambulatory surgery center by one of 3 physicians. The complications encountered during the procedure and postoperatively were prospectively evaluated. Measurable outcomes employed were intravascular entry of the needle, profuse bleeding, local hematoma, bruising, dural puncture and headache, nerve root or spinal cord irritation with resultant injury, infectious complications, vasovagal reactions, and facial flushing. Intravascular entry was higher for adhesiolysis (11.6%) and lumbar transforaminal (7.9%) procedures compared to other epidurals which

  12. The fluoroscopic barium enema in colonic polyp detection.

    Science.gov (United States)

    Teefey, S A; Carlson, H C

    1983-12-01

    The results of 1,500 barium enema studies done by vigorous manual palpation under fluoroscopy were reviewed to determine the adequacy of this technique in detecting polyps above the proctoscopic level. Of the 1,500 patients examined, 103 (7%) were diagnosed radiographically as having a total of 149 polyps. Polyps were found at proctoscopy in about 10% of the 1,500 patients. Colonoscopy or surgery was performed on 35 of the 103 patients. Of the 52 polyps discovered during these procedures, only three were missed at fluoroscopic barium enema study, a false-negative rate of 6%. Fourteen patients whose barium enemas initially were reported as negative for polyps or neoplasia had colonoscopy. Two of the 14 patients had positive findings, for a true-negative rate of 86%. If the detection rate of 7% found at barium enema, taking into account an overlap of 10%, is combined with the rate of 7.5% found at proctoscopy, a frequency of about 14% emerges in detecting polyps in the rectum and in the colon. Thus, the fluoroscopic barium enema when combined with proctoscopy is a sensitive method in the detection of colorectal polyps. In addition, it has the advantage of rapid execution and relatively low cost.

  13. Digital breast tomosynthesis: Dose and image quality assessment.

    Science.gov (United States)

    Maldera, A; De Marco, P; Colombo, P E; Origgi, D; Torresin, A

    2017-01-01

    The aim of this work was to evaluate how different acquisition geometries and reconstruction parameters affect the performance of four digital breast tomosynthesis (DBT) systems (Senographe Essential - GE, Mammomat Inspiration - Siemens, Selenia Dimensions - Hologic and Amulet Innovality - Fujifilm) on the basis of a physical characterization. Average Glandular Dose (AGD) and image quality parameters such as in-plane/in-depth resolution, signal difference to noise ratio (SDNR) and artefact spread function (ASF) were examined. Measured AGD values resulted below EUREF limits for 2D imaging. A large variability was recorded among the investigated systems: the mean dose ratio DBT/2D ranged between 1.1 and 1.9. In-plane resolution was in the range: 2.2mm(-1)-3.8mm(-1) in chest wall-nipple direction. A worse resolution was found for all devices in tube travel direction. In-depth resolution improved with increasing scan angle but was also affected by the choice of reconstruction and post-processing algorithms. The highest z-resolution was provided by Siemens (50°, FWHM=2.3mm) followed by GE (25°, FWHM=2.8mm), while the Fujifilm HR showed the lowest one, despite its wide scan angle (40°, FWHM=4.1mm). The ASF was dependent on scan angle: smaller range systems showed wider ASF curves; however a clear relationship was not found between scan angle and ASF, due to the different post processing and reconstruction algorithms. SDNR analysis, performed on Fujifilm system, demonstrated that pixel binning improves detectability for a fixed dose/projection. In conclusion, we provide a performance comparison among four DBT systems under a clinical acquisition mode. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  14. TRANSPORTATION CASK RECEIPT AND RETURN FACILITY WORKER DOSE ASSESSMENT

    Energy Technology Data Exchange (ETDEWEB)

    V. Arakali

    2005-02-24

    The purpose of this design calculation is to estimate radiation doses received by personnel working in the Transportation Cask Receipt and Return Facility (TCRRF) of the repository including the personnel at the security gate and cask staging areas. This calculation is required to support the preclosure safety analysis (PCSA) to ensure that the predicted doses are within the regulatory limits prescribed by the U.S. Nuclear Regulatory Commission (NRC). The Cask Receipt and Return Facility receives NRC licensed transportation casks loaded with spent nuclear fuel (SNF) and high-level radioactive waste (HLW). The TCRRF operation starts with the receipt, inspection, and survey of the casks at the security gate and the staging areas, and proceeds to the process facilities. The transportation casks arrive at the site via rail cars or trucks under the guidance of the national transportation system. This calculation was developed by the Environmental and Nuclear Engineering organization and is intended solely for the use of Design and Engineering in work regarding facility design. Environmental and Nuclear Engineering personnel should be consulted before using this calculation for purposes other than those stated herein or for use by individuals other than authorized personnel in the Environmental and Nuclear Engineering organization.

  15. Assessment of effective dose to staff in brachytherapy.

    Science.gov (United States)

    Faulkner, K; James, H V; Chapple, C L; Rawlings, D J

    1996-11-01

    The aim of this paper is to investigate the problem of monitoring effective dose to hospital staff who are involved in the treatment of tumors using sealed sources placed inside the body (brachytherapy). In addition, the use of an unsealed source to treat the thyroid was also considered. Radiation distributions produced by both sealed sources commonly used in brachytherapy (192I, 137Cs, 226Ra) and an unsealed source used in the treatment of the thyroid (131I) were used to irradiate a Rando phantom. The brachytherapy treatments of esophageal and gynecological carcinoma were simulated. The Rando phantom was loaded with lithium fluoride thermoluminescent dosimeters at positions corresponding to a number of radiosensitive organs. Film badges and electronic personal dosimeters were attached to the Rando phantom at various anatomical sites. The Rando phantom was positioned adjacent to the patient at an angle of 90 degrees to the longitudinal axis of the patient. Irradiations were performed with and without a portable lead screen used on the radiotherapy wards. Effective dose was estimated for each simulated radiotherapy treatment and compared with the personal monitor readings. The data were used as a basis for the provision of advice on the wearing of the film badge dosimeters and the design of portable lead screens. The data also permitted a comparison between the two types of dosimeter when used for personal monitoring in brachytherapy.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-09-15

    The study examined the changes in the decreased facial exposure dose for radiological technologists depending on increased distance between the workers and the X-ray tube head during intraoral radiography. First, the facial phantom similar to the human tissues was manufactured. The shooting examination was configured to the maxillary molars for adults (60 kVp, 10 mA, 50 msec) and for children (60 kVp, 10 mA, 20 msec), and the chamber was fixed where the facial part of the radiation worker would be placed using the intraoral radiography equipment. The distances between the X-ray tube head and the phantom were set to 10 cm, 15 cm, 20 cm, 25 cm, 30 cm, 35 cm, and 40 cm. The phantom was radiated 20 times with each examination condition and the average scattered doses were examined. The rate at the distance of 40 cm decreased by about 92.6% to 7.43% based on the scattered rays radiated at the distance of 10 cm under the adult conditions. The rate at the distance of 40 cm decreased by about 97.6% to 2.58% based on the scattered rays radiated at the distance of 10 cm under the children conditions. Protection from the radiation exposure was required during the dental radiographic examination.

  17. EMP Attachment 3 DOE-SC PNNL Site Dose Assessment Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, Sandra F.

    2011-12-21

    This Dose Assessment Guidance (DAG) describes methods to use to determine the Maximally-Exposed Individual (MEI) location and to estimate dose impact to that individual under the U.S. Department of Energy Office of Science (DOE-SC) Pacific Northwest National Laboratory (PNNL) Site Environmental Monitoring Plan (EMP). This guidance applies to public dose from radioactive material releases to the air from PNNL Site operations. This document is an attachment to the Pacific Northwest National Laboratory (PNNL) Environmental Monitoring Plan (EMP) and describes dose assessment guidance for radiological air emissions. The impact of radiological air emissions from the U.S. Department of Energy Office of Science (DOE-SC) PNNL Site is indicated by dose estimates to a maximally exposed member of the public, referred to as the maximally exposed individual (MEI). Reporting requirements associated with dose to members of the public from radiological air emissions are in 40 CFR Part 61.94, WAC 246-247-080, and DOE Order 458.1. The DOE Order and state standards for dose from radioactive air emissions are consistent with U.S. Environmental Protection Agency (EPA) dose standards in 40 CFR 61.92 (i.e., 10 mrem/yr to a MEI). Despite the fact that the current Contract Requirements Document (CRD) for the DOE-SC PNNL Site operations does not include the requirement to meet DOE CRD 458.1, paragraph 2.b, public dose limits, the DOE dose limits would be met when EPA limits are met.

  18. Using the Monte Carlo method for assessing the tissue and organ doses of patients in dental radiography

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-07-24

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

  20. Assessment of PAtient Doses During mAmmogrAPhy PrActice At ...

    African Journals Online (AJOL)

    2011-11-11

    Nov 11, 2011 ... specific tests on the mammography x-ray unit, image quality assessment, consistency tests, and radiation dose ... The equipment has manual and AEC systems, Mo/Mo ..... inclusion of the denser pectoral muscle in the image.

  1. Slope of the dose-response curve: usefulness in assessing bronchial responses to inhaled histamine.

    OpenAIRE

    Cockcroft, D. W.; Berscheid, B A

    1983-01-01

    The value of determining the slope of the histamine dose-response curve, in addition to the histamine provocation concentration producing a 20% reduction in FEV1 (PC20-FEV1), was assessed by analysis of histamine dose-response curves in 40 patients selected as having a wide range of increased non-specific bronchial responsiveness to inhaled histamine. The histamine dose-response curves were found to be fit the linear curve (dose v response, mean r2 = 0.97) better than the logarithmic curve (l...

  2. Boron Diffused Thermoluminescent Surface Layer in LiF TLDs for Skin Dose Assessments

    DEFF Research Database (Denmark)

    Christensen, Poul; Majborn, Benny

    1980-01-01

    A new high-temperature glow peak produced in a thin surface layer of LiF TLDs by diffusion of boron into the LiF material has been studied for skin dose assessments in personnel dosimetry.......A new high-temperature glow peak produced in a thin surface layer of LiF TLDs by diffusion of boron into the LiF material has been studied for skin dose assessments in personnel dosimetry....

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

    Science.gov (United States)

    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

  4. Reduced-dose CT protocol for the assessment of cerebral vasospasm

    Energy Technology Data Exchange (ETDEWEB)

    Bricout, N.; Estrade, L.; Boustia, F.; Kalsoum, E.; Pruvo, J.P.; Leclerc, X. [Hopital Roger Salengro, CHRU de Lille, Department of Neuroradiology, Universite Lille Nord de France, Lille cedex (France)

    2015-12-15

    Despite the increased radiation dose, multimodal CT including noncontrast CT (NCT), CT angiography (CTA), and perfusion CT (PCT) remains a useful tool for the diagnosis of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH). The aim of this study was to assess the radiation dose and the image quality between a standard-dose and a reduced-dose multimodal CT protocol. The study group consisted of 26 aSAH patients with a suspicion of DCI on clinical examination and transcranial doppler. Two different CT protocols were used: a standard-dose protocol (NCT 120 kV, 350 mAs; CTA 100 kV, 250 mAs; PCT 80 kV, 200 mAs) from August 2011 to October 2013 (n = 13) and a reduced-dose protocol (NCT 100 kV, 400 mAs; CTA 100 kV, 220 mAs; PCT 80 kV, 180 mAs) from November 2013 to May 2014 (n = 13). Dose-length product (DLP), effective dose, volume CT dose index (CTDI), signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and overall image quality were determined for each examination. The overall image quality was judged as good or excellent in all cases. The reduced-dose protocol allowed a 15 % decrease in both the median total DLP (2438 vs 2898 mGy cm, p < 0.0001) and the effective dose as well as a significant decrease in median CTDI of 23, 31, and 10 % for NCT, CTA, and CTP, respectively. This dose reduction did not result in significant alteration of SNR (except for NCT) or CNR between groups. The present study showed that the reduced-dose multimodal CT protocol enabled a significant reduction of radiation dose without image quality impairment. (orig.)

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

    DEFF Research Database (Denmark)

    Kjellström, Tord; Grandjean, Philippe

    2007-01-01

    and their compounds. An entirely new structure and illustrations represent the vast array of advancements made since the last edition. Special emphasis has been placed on the toxic effects in humans with chapters on the diagnosis, treatment and prevention of metal poisoning. This up-to-date reference provides easy...... and Toxicity Carcinogenicity of Metal Compounds Immunotoxicology of Metals Reproductive and Developmental Toxicity of Metals Ecotoxicology of Metals - Sources, Transport, and Effects in the Ecosystem Risk Assessment Diagnosis and Treatment of Metal Poisoning - General Aspects Principles for Prevention...... of the Toxic Effects of Metals Aluminum Antimony Arsenic Barium Beryllium Bismuth Cadmium Chromium Cobalt Copper Gallium and Semiconductor Compounds Germanium Indium Iron Lead Manganese Mercury Molybdenum Nickel Palladium Platinum Selenium Silver Tellurium Thallium Tin Titanium Tungsten Uranium Vanadium Zinc...

  6. Dosimetry experiences and lessons learned for radiation dose assessment in Korean nuclear power plants.

    Science.gov (United States)

    Choi, Jong Rak; Kim, Hee Geun; Kong, Tae Young; Son, Jung Kwon

    2013-07-01

    Since the first Korean nuclear power plant (NPP), Kori 1, commenced operation in 1978, a total of 21 NPPs had been put into operation in Korea by the end of 2011. Radiation doses of NPP workers have been periodically evaluated and controlled within the prescribed dose limit. Radiation dose assessment is carried out monthly by reading personal dosemeters for external radiation exposure, which have traceability in compliance with strict technical guidelines. In the case of the internal radiation exposure, workers who have access to the possible area of polluted air are also evaluated for their internal dose after maintenance task. In this article, the overall situation and experience for the assessment and distribution of radiation doses in Korean NPPs is described.

  7. Establishment of a radiological dose assessment system for HANARO emergency preparedness

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-12-01

    A radiological dose assessment system has been established to calculate the three-dimensional wind field based on the observed data at meteorological towers, and to calculate the exposure dose in the radiological accidents or for emergency training. The wind fields program has been constructed to calculate the real-time wind field using the atmospheric stability and the diffusion parameters based on the meteorological data sets measured from two meteorological towers. The result is separated into the effective dose and thyroid dose with 4 age groups such as infant, children, teenage and adult. Dose rate and cumulated dose for above each termare calculated and repeated for the prediction and modification according to the elapsed time. The evaluated data sets are displayed on the map around KAERI site with social and environmental information which is made with GIS. (author)

  8. Auto-shape lossless compression of pharynx and esophagus fluoroscopic images.

    Science.gov (United States)

    Arif, Arif Sameh; Mansor, Sarina; Logeswaran, Rajasvaran; Karim, Hezerul Abdul

    2015-02-01

    The massive number of medical images produced by fluoroscopic and other conventional diagnostic imaging devices demand a considerable amount of space for data storage. This paper proposes an effective method for lossless compression of fluoroscopic images. The main contribution in this paper is the extraction of the regions of interest (ROI) in fluoroscopic images using appropriate shapes. The extracted ROI is then effectively compressed using customized correlation and the combination of Run Length and Huffman coding, to increase compression ratio. The experimental results achieved show that the proposed method is able to improve the compression ratio by 400 % as compared to that of traditional methods.

  9. Assessment of inhalation dose sensitivity by physicochemical properties of airborne particulates containing naturally occurring radioactive materials

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Si Young; Choi, Cheol Kyu; Kim, Yong Geon; Choi, Won Chul; Kim, Kwang Pyo [Kyung Hee University, Seoul (Korea, Republic of)

    2015-12-15

    Facilities processing raw materials containing naturally occurring radioactive materials (NORM) may give rise to enhanced radiation dose to workers due to chronic inhalation of airborne particulates. Internal radiation dose due to particulate inhalation varies depending on particulate properties, including size, shape, density, and absorption type. The objective of the present study was to assess inhalation dose sensitivity to physicochemical properties of airborne particulates. Committed effective doses to workers resulting from inhalation of airborne particulates were calculated based on International Commission on Radiological Protection 66 human respiratory tract model. Inhalation dose generally increased with decreasing particulate size. Committed effective doses due to inhalation of 0.01μm sized particulates were higher than doses due to 100μm sized particulates by factors of about 100 and 50 for {sup 238}U and {sup 230}Th, respectively. Inhalation dose increased with decreasing shape factor. Shape factors of 1 and 2 resulted in dose difference by about 18 %. Inhalation dose increased with particulate mass density. Particulate mass densities of 11 g·cm{sup -3} and 0.7 g·cm{sup -3} resulted in dose difference by about 60 %. For {sup 238}U, inhalation doses were higher for absorption type of S, M, and F in that sequence. Committed effective dose for absorption type S of {sup 238}U was about 9 times higher than dose for absorption F. For {sup 230}Th, inhalation doses were higher for absorption type of F, M, and S in that sequence. Committed effective dose for absorption type F of {sup 230}Th was about 16 times higher than dose for absorption S. Consequently, use of default values for particulate properties without consideration of site specific physiochemical properties may potentially skew radiation dose estimates to unrealistic values up to 1-2 orders of magnitude. For this reason, it is highly recommended to consider site specific working materials and

  10. Assessment of adequacy of hemodialysis dose at a Palestinian hospital

    Directory of Open Access Journals (Sweden)

    Heba Adas

    2014-01-01

    Full Text Available Adequacy of hemodialysis improves patient survival, quality of life and biochemical outcomes and minimizes disease complications and hospitalizations. This study was an observational cross-sectional study that was conducted in July 2012. Blood tests, weight and blood pressure were measured before and after hemodialysis. Single-pool Kt/V and urea reduction ratio (URR were calculated. The targets based on the National Kidney Foundation Disease Outcomes Quality Initiative (KDOQI Clinical Practice Guidelines were Kt/V ≥ 1.2 and URR ≥ 65%. Of the 64 patients, 41 (64.1% were males. The mean age of the patients was 58.13 ± 17.2 years. The mean body mass index (BMI was 25.04 ± 5.01 kg/m 2 . The mean Kt/V and URR were 1.06 ± 0.05 and 54.4 ± 19.3, respectively. There was no significant difference between men and women (1.06 ± 0.47 versus 1.04 ± 0.55, P = 0.863 and (54.7 ± 19.59 versus 53.81 ± 19.17, P = 0.296. Only 25 (39.1% patients achieved the Kt/V goal and only 22 (34.4% had target URR, and there was no significant association between hemodialysis adequacy and any of the variables such as sex, age, presence of chronic diseases or BMI. Serum potassium levels post-dialysis were significantly lower in patients who reached the target Kt/V (mean = 3.44 ± 0.48 versus 3.88 ± 0.48, P = 0.001. Most patients were inadequately dialyzed and a large percentage of the patients did not attain the targets. Attempts to achieve the desired goals are necessary. It is important to calculate Kt/V or URR and individualize the dialysis doses for each patient.

  11. ANDROS: A code for Assessment of Nuclide Doses and Risks with Option Selection

    Energy Technology Data Exchange (ETDEWEB)

    Begovich, C.L.; Sjoreen, A.L.; Ohr, S.Y.; Chester, R.O.

    1986-11-01

    ANDROS (Assessment of Nuclide Doses and Risks with Option Selection) is a computer code written to compute doses and health effects from atmospheric releases of radionuclides. ANDROS has been designed as an integral part of the CRRIS (Computerized Radiological Risk Investigation System). ANDROS reads air concentrations and environmental concentrations of radionuclides to produce tables of specified doses and health effects to selected organs via selected pathways (e.g., ingestion or air immersion). The calculation may be done for an individual at a specific location or for the population of the whole assessment grid. The user may request tables of specific effects for every assessment grid location. Along with the radionuclide concentrations, the code requires radionuclide decay data, dose and risk factors, and location-specific data, all of which are available within the CRRIS. This document is a user manual for ANDROS and presents the methodology used in this code.

  12. Development of environmental dose assessment system (EDAS) code of PC version

    CERN Document Server

    Taki, M; Kobayashi, H; Yamaguchi, T

    2003-01-01

    A computer code (EDAS) was developed to assess the public dose for the safety assessment to get the license of nuclear reactor operation. This code system is used for the safety analysis of public around the nuclear reactor in normal operation and severe accident. This code was revised and composed for personal computer user according to the Nuclear Safety Guidelines reflected the ICRP1990 recommendation. These guidelines are revised by Nuclear Safety Commission on March, 2001, which are 'Weather analysis guideline for the safety assessment of nuclear power reactor', 'Public dose around the facility assessment guideline corresponding to the objective value for nuclear power light water reactor' and 'Public dose assessment guideline for safety review of nuclear power light water reactor'. This code has been already opened for public user by JAERI, and English version code and user manual are also prepared. This English version code is helpful for international cooperation concerning the nuclear safety assessme...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-01-01

    Inspection and repair of tower structure and lift, instrument calibration have been done. Wireless data transmission to MIPS (Meteorological Information Processing System) has been done after collection in the DAS where environmental assessment can be done by the developed simulation programs in both cases of normal operation and emergency. Wind direction, wind speed, temperature, humidity at 67m, 27m, and 10m height and temperature, humidity, atmospheric pressure, solar radiation, precipitation, and visibility at surface have been measured analyzed with statistical methods. At the site, the prevailing wind directions were SW in spring and summer, NNW in winter season. (author). 6 refs., 9 tabs., 4 figs.

  14. Radiological dose assessments at the Kennedy Space Center

    Energy Technology Data Exchange (ETDEWEB)

    Firstenberg, H.; Jubach, R.; Bartram, B.; Vaughan, F.

    1989-01-01

    This paper discusses the application of an atmospheric transport and diffusion model for launch window and safety risk assessment studies in support of the Galileo (which is scheduled for the October/November 1989 period) and Ulysses (scheduled for {approximately}1 yr after Galileo) missions at the Kennedy Space Center (KSC). The model is resident in the EMERGE software system developed by NUS Corporation and modified for the U.S. Department of Energy (DOE) to provide real-time and safety analyses report support for the launches. The application is unique in that the model accommodates the varied amount of meteorological data at KSC and Cape Canaveral and includes a site-specific algorithm to account for local-scale circulations. This paper focuses on the Galileo mission application, including discussions of the use of the meteorological data available at KSC, integration of the EMERGE sea-breeze algorithm, and examples of real-time and safety analyses report assessments. The Galileo spacecraft is to be launched toward Jupiter using the space shuttle.

  15. Dose-response assessment using the benchmark dose approach of changes in hepatic EROD activity for individual polychlorinated biphenyl congeners

    Energy Technology Data Exchange (ETDEWEB)

    Fattore, E.; Fanelli, R. [' ' Mario Negri' ' Institute for Pharmacological Research, Milan (Italy); Chu, I. [Safe Environments Programme, Healthy Environments and Consumer Safety Branch, Tunney' s Pasture, Ottawa, ON (Canada); Sand, S.; Haakansson, H. [Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden); Falk-Filippson, A. [Swedish Chemicals Inspectorate, Sundbyberg (Sweden)

    2004-09-15

    The benchmark dose (BMD) approach was proposed as an alternative to the no-observedadverse- effect-level (NOAEL) or the lowest-observed-adverse-effect-level (LOAEL) as point of departure (POD) for extrapolation of data from animal studies to the low dose human exposure situation. In the risk assessment process using the NOAEL/LOAEL parameter, the reference dose (RfD) or the admissible daily intake (ADI) is obtained by dividing the NOAEL/LOAEL value by uncertainty factors. The uncertainty factors are incorporated in order to take into account variability in the sensitivity of different species, inter-individual differences in sensitivity within the human population, and variability in experimental data. In the BMD approach a dose-response curve is fitted to experimental data (Figure 1) and the BMD is calculated from the equation of the curve as the dose corresponding to a predetermined change in the response defined as the benchmark response (BMR). The 95% lower confidence bound of the BMD, usually referred to as BMDL, can be used as the POD in the extrapolation process to get a RfD or an ADI. The advantages of using the BMD approach are many. First, all the experimental data are utilized to construct the doseresponse curve; second, the variability and uncertainty are taken into account by incorporating standard deviations of means; and third, it represents a single methodology for cancer and noncancer endpoints. In this study the BMD methodology was applied to evaluate dose-response data of seven chlorinated biphenyl (CB) congeners (Table 1), some of which are dioxin-like while others are not. The data were obtained from subchronic dietary exposure studies in male and female Sprague Dawley rats. Elevation in ethoxyresorufin-O-deethylase (EROD) activity was selected as biological response because it is known to be an endpoint sensitive to the exposure of dioxin-like PCBs. Since this response is not an adverse effect per se, in this paper we will refer to the no

  16. 3D-printed applicators for high dose rate brachytherapy: Dosimetric assessment at different infill percentage.

    Science.gov (United States)

    Ricotti, Rosalinda; Vavassori, Andrea; Bazani, Alessia; Ciardo, Delia; Pansini, Floriana; Spoto, Ruggero; Sammarco, Vittorio; Cattani, Federica; Baroni, Guido; Orecchia, Roberto; Jereczek-Fossa, Barbara Alicja

    2016-12-01

    Dosimetric assessment of high dose rate (HDR) brachytherapy applicators, printed in 3D with acrylonitrile butadiene styrene (ABS) at different infill percentage. A low-cost, desktop, 3D printer (Hamlet 3DX100, Hamlet, Dublin, IE) was used for manufacturing simple HDR applicators, reproducing typical geometries in brachytherapy: cylindrical (common in vaginal treatment) and flat configurations (generally used to treat superficial lesions). Printer accuracy was investigated through physical measurements. The dosimetric consequences of varying the applicator's density by tuning the printing infill percentage were analysed experimentally by measuring depth dose profiles and superficial dose distribution with Gafchromic EBT3 films (International Specialty Products, Wayne, NJ). Dose distributions were compared to those obtained with a commercial superficial applicator. Measured printing accuracy was within 0.5mm. Dose attenuation was not sensitive to the density of the material. Surface dose distribution comparison of the 3D printed flat applicators with respect to the commercial superficial applicator showed an overall passing rate greater than 94% for gamma analysis with 3% dose difference criteria, 3mm distance-to-agreement criteria and 10% dose threshold. Low-cost 3D printers are a promising solution for the customization of the HDR brachytherapy applicators. However, further assessment of 3D printing techniques and regulatory materials approval are required for clinical application. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ould-Dada, Z. E-mail: zitouni.ould-dada@foodstandards.gsi.gov.uk; Tucker, S.; Webbe-Wood, D.; Mondon, K.; Hunt, J

    2002-07-01

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

  18. Fluoroscope Study of Lesser Snow Geese at Sabine National Wildlife Refuge, Louisiana

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This dataset contains the results of a fluoroscope study of Lesser Snow Geese wintering at Sabine National Wildlife Refuge in November of 1974.

  19. The AAPM/RSNA physics tutorial for residents: general overview of fluoroscopic imaging.

    Science.gov (United States)

    Schueler, B A

    2000-01-01

    Fluoroscopy is used to visualize the motion of internal fluids, structures, and devices. During a fluoroscopic examination, the operator controls activation of the x-ray tube for real-time imaging of the patient. The article provides a general overview of fluoroscopic imaging from its initial development to modern use. Early fluoroscopes produced a dim image on a fluorescent screen that required dark adaptation of the physician's eyes to optimize viewing conditions. Image intensifiers were later developed to replace the fluorescent screen and increase image brightness. Modern fluoroscopy systems include an image intensifier with television image display and a choice of several different types of image recording devices. Fluoroscopic equipment is available in many different configurations for use in a wide variety of clinical applications.

  20. Assessment of the dose from radon and its decay products in the Bozkov dolomite cave.

    Science.gov (United States)

    Rovenská, K; Thinová, L; Zdímal, V

    2008-01-01

    The dose from radon and its progeny remains a frequently discussed problem. ICRP 65 provides a commonly used methodology to calculate the dose from radon. Our work focuses on a cave environment and on assessing the doses in public open caves. The differences in conditions (aerosol size distribution, humidity, radon and its progeny ratio, etc.) are described by the so-called cave factor j. The cave factor is used to correct the dose for workers which is calculated using the ICRP 65 recommendation. In this work, the authors have brought together measured data of aerosol size distribution, unattached and attached fraction activity, and have calculated the so-called cave factor for the Bozkov dolomite cave environment. The dose conversion factors based on measured data and used for evaluating the cave factor were calculated by LUDEP software, which implements HRTM ICRP66.

  1. X-ray characterization of CMOS imaging detector with high resolution for fluoroscopic imaging application

    Science.gov (United States)

    Cha, Bo Kyung; Kim, Cho Rong; Jeon, Seongchae; Kim, Ryun Kyung; Seo, Chang-Woo; Yang, Keedong; Heo, Duchang; Lee, Tae-Bum; Shin, Min-Seok; Kim, Jong-Boo; Kwon, Oh-Kyung

    2013-12-01

    This paper introduces complementary metal-oxide semiconductor (CMOS) active pixel sensor (APS)-based X-ray imaging detectors with high spatial resolution for medical imaging application. In this study, our proposed X-ray CMOS imaging sensor has been fabricated by using a 0.35 μm 1 Poly 4 Metal CMOS process. The pixel size is 100 μm×100 μm and the pixel array format is 24×96 pixels, which provide a field-of-view (FOV) of 9.6 mm×2.4 mm. The 14.3-bit extend counting analog-to digital converter (ADC) with built-in binning mode was used to reduce the area and simultaneously improve the image resolution. Both thallium-doped CsI (CsI:Tl) and Gd2O2S:Tb scintillator screens were used as converters for incident X-rays to visible light photons. The optical property and X-ray imaging characterization such as X-ray to light response as a function of incident X-ray exposure dose, spatial resolution and X-ray images of objects were measured under different X-ray energy conditions. The measured results suggest that our developed CMOS-based X-ray imaging detector has the potential for fluoroscopic imaging and cone-beam computed tomography (CBCT) imaging applications.

  2. Identification and dose assessment of irradiated cardamom and cloves by EPR spectrometry

    Science.gov (United States)

    Beshir, W. B.

    2014-03-01

    The use of electron paramagnetic resonance spectroscopy to accurately distinguish irradiated from unirradiated cardamom and cloves and assesses the absorbed dose to radiation processed cardamom and cloves are examined. The results were successful for identifying both irradiated and unirradiated cardamom and cloves. Additive reirradiation of cardamom and cloves produces reproducible dose-response functions, which can be used to assess the initial dose by back-extrapolation. Third degree polynomial function was used to fit the EPR signal/dose curves. It was found that this 3rd degree polynomial function provides satisfactory results without correction of decay for free radicals. The stability of the radiation induced EPR signal of irradiated cardamom and cloves were studied over a storage period of almost 8 months.

  3. Realistic retrospective dose assessments to members of the public around Spanish nuclear facilities

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, M.A., E-mail: majg@csn.es [Consejo de Seguridad Nuclear (CSN), Pedro Justo Dorado Dellmans 11, E-28040 Madrid (Spain); Martin-Valdepenas, J.M.; Garcia-Talavera, M.; Martin-Matarranz, J.L.; Salas, M.R.; Serrano, J.I.; Ramos, L.M. [Consejo de Seguridad Nuclear (CSN), Pedro Justo Dorado Dellmans 11, E-28040 Madrid (Spain)

    2011-11-15

    In the frame of an epidemiological study carried out in the influence areas around the Spanish nuclear facilities (ISCIII-CSN, 2009. Epidemiological Study of The Possible Effect of Ionizing Radiations Deriving from The Operation of Spanish Nuclear Fuel Cycle Facilities on The Health of The Population Living in Their Vicinity. Final report December 2009. Ministerio de Ciencia e Innovacion, Instituto de Salud Carlos III, Consejo de Seguridad Nuclear. Madrid. Available from: (http://www.csn.es/images/stories/actualidad{sub d}atos/especiales/epidemiologico/epidemiological{sub s}tudy.pdf)), annual effective doses to public have been assessed by the Spanish Nuclear Safety Council (CSN) for over 45 years using a retrospective realistic-dose methodology. These values are compared with data from natural radiation exposure. For the affected population, natural radiation effective doses are in average 2300 times higher than effective doses due to the operation of nuclear installations (nuclear power stations and fuel cycle facilities). When considering the impact on the whole Spanish population, effective doses attributable to nuclear facilities represent in average 3.5 x 10{sup -5} mSv/y, in contrast to 1.6 mSv/y from natural radiation or 1.3 mSv/y from medical exposures. - Highlights: > Most comprehensive dose assessment to public by nuclear facilities ever done in Spain. > Dose to public is dominated by liquid effluent pathways for the power stations. > Dose to public is dominated by Rn inhalation for milling and mining facilities. > Average annual doses to public in influence areas are negligible (10 {mu}Sv/y or less). > Doses from facilities average 3.5 x 10{sup -2} {mu}Sv/y per person onto whole Spanish population.

  4. Qualitative and quantitative approaches in the dose-response assessment of genotoxic carcinogens.

    Science.gov (United States)

    Fukushima, Shoji; Gi, Min; Kakehashi, Anna; Wanibuchi, Hideki; Matsumoto, Michiharu

    2016-05-01

    Qualitative and quantitative approaches are important issues in field of carcinogenic risk assessment of the genotoxic carcinogens. Herein, we provide quantitative data on low-dose hepatocarcinogenicity studies for three genotoxic hepatocarcinogens: 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) and N-nitrosodiethylamine (DEN). Hepatocarcinogenicity was examined by quantitative analysis of glutathione S-transferase placental form (GST-P) positive foci, which are the preneoplastic lesions in rat hepatocarcinogenesis and the endpoint carcinogenic marker in the rat liver medium-term carcinogenicity bioassay. We also examined DNA damage and gene mutations which occurred through the initiation stage of carcinogenesis. For the establishment of points of departure (PoD) from which the cancer-related risk can be estimated, we analyzed the above events by quantitative no-observed-effect level and benchmark dose approaches. MeIQx at low doses induced formation of DNA-MeIQx adducts; somewhat higher doses caused elevation of 8-hydroxy-2'-deoxyquanosine levels; at still higher doses gene mutations occurred; and the highest dose induced formation of GST-P positive foci. These data indicate that early genotoxic events in the pathway to carcinogenesis showed the expected trend of lower PoDs for earlier events in the carcinogenic process. Similarly, only the highest dose of IQ caused an increase in the number of GST-P positive foci in the liver, while IQ-DNA adduct formation was observed with low doses. Moreover, treatment with DEN at low doses had no effect on development of GST-P positive foci in the liver. These data on PoDs for the markers contribute to understand whether genotoxic carcinogens have a threshold for their carcinogenicity. The most appropriate approach to use in low dose-response assessment must be approved on the basis of scientific judgment.

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

    Energy Technology Data Exchange (ETDEWEB)

    Smith, K.P.; Blunt, D.L.; Williams, G.P. [Argonne National Lab., IL (United States). Environmental Assessment Div.; Tebes, C.L. [Univ. of Illinois, Urbana, IL (United States)

    1996-09-01

    A preliminary radiological dose assessment of equipment decontamination, subsurface disposal, landspreading, equipment smelting, and equipment burial was conducted to address concerns regarding the presence of naturally occurring radioactive materials (NORM) in production waste streams. The assessment estimated maximum individual dose equivalents for workers and the general public. Sensitivity analyses of certain input parameters also were conducted. On the basis of this assessment, it is concluded that (1) regulations requiring workers to wear respiratory protection during equipment cleaning operations are likely to result in lower worker doses, (2) underground injection and downhole encapsulation of NORM wastes present a negligible risk to the general public, and (3) potential doses to workers and the general public related to smelting NORM-contaminated equipment can be controlled by limiting the contamination level of the initial feed. It is recommended that (1) NORM wastes be further characterized to improve studies of potential radiological doses; (2) states be encouraged to permit subsurface disposal of NORM more readily, provided further assessments support this study; results; (3) further assessment of landspreading NORM wastes be conducted; and (4) the political, economic, sociological, and nonradiological issues related to smelting NORM-contaminated equipment be studied to fully examine the feasibility of this disposal option.

  6. Characteristics of the graded wildlife dose assessment code K-BIOTA and its application

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-12-15

    This paper describes the technical background for the Korean wildlife radiation dose assessment code, K-BIOTA, and the summary of its application. The K-BIOTA applies the graded approaches of 3 levels including the screening assessment (Level 1 and 2), and the detailed assessment based on the site specific data (Level 3). The screening level assessment is a preliminary step to determine whether the detailed assessment is needed, and calculates the dose rate for the grouped organisms, rather than an individual biota. In the Level 1 assessment, the risk quotient (RQ) is calculated by comparing the actual media concentration with the environmental media concentration limit (EMCL) derived from a bench-mark screening reference dose rate. If RQ for the Level 1 assessment is less than 1, it can be determined that the ecosystem would maintain its integrity, and the assessment is terminated. If the RQ is greater than 1, the Level 2 assessment, which calculates RQ using the average value of the concentration ratio (CR) and equilibrium distribution coefficient (Kd) for the grouped organisms, is carried out for the more realistic assessment. Thus, the Level 2 assessment is less conservative than the Level 1 assessment. If RQ for the Level 2 assessment is less than 1, it can be determined that the ecosystem would maintain its integrity, and the assessment is terminated. If the RQ is greater than 1, the Level 3 assessment is performed for the detailed assessment. In the Level 3 assessment, the radiation dose for the representative organism of a site is calculated by using the site specific data of occupancy factor, CR and Kd. In addition, the K-BIOTA allows the uncertainty analysis of the dose rate on CR, Kd and environmental medium concentration among input parameters optionally in the Level 3 assessment. The four probability density functions of normal, lognormal, uniform and exponential distribution can be applied. The applicability of the code was tested through the

  7. The debate on the use of linear no threshold for assessing the effects of low doses

    Energy Technology Data Exchange (ETDEWEB)

    Tubiana, M; Aurengo, A; Averbeck, D; Masse, R [Centre Antoine Beclere, 45 rue des Saints-Peres, 75006 Paris (France)

    2006-09-15

    From December 2004 to July 2005, three reports on the effects of low doses of ionising radiation were released: ICRP (2004), the joint report of the French Academies of Science and Medicine (Tubiana et al 2005), and a report from the American Academy of Sciences (BEIR VII 2005). These reports quote the same recent articles on the biological effects of low doses, yet their conclusions diverge. The French report concludes that recent biological data show that the efficacy of defense mechanisms is modulated by dose and dose rate and that linear no threshold (LNT) is no longer plausible. The ICRP and the BEIR VII reports recognise that there are biologic arguments against LNT but feel that there are not sufficient biological proofs against it to change risk assessment methodology and subsequent regulatory policy based on LNT. They point out the remaining uncertainties and the lack of mechanistic explanations of phenomena such as low dose hyperlethality or the adaptive response. In this context, a critical analysis of the available data is necessary. The epidemiological data and the experimental data challenge the validity of the LNT hypothesis for assessing the carcinogenic effect of low doses, but do not allow its exclusion. Therefore, the main criteria for selecting the most reliable dose-effect relationship from a scientific point of view should be based on biological data. Their analysis should help one to understand the current controversy. (opinion)

  8. The debate on the use of linear no threshold for assessing the effects of low doses.

    Science.gov (United States)

    Tubiana, M; Aurengo, A; Averbeck, D; Masse, R

    2006-09-01

    From December 2004 to July 2005, three reports on the effects of low doses of ionising radiation were released: ICRP (2004), the joint report of the French Academies of Science and Medicine (Tubiana et al 2005), and a report from the American Academy of Sciences (BEIR VII 2005). These reports quote the same recent articles on the biological effects of low doses, yet their conclusions diverge. The French report concludes that recent biological data show that the efficacy of defense mechanisms is modulated by dose and dose rate and that linear no threshold (LNT) is no longer plausible. The ICRP and the BEIR VII reports recognise that there are biologic arguments against LNT but feel that there are not sufficient biological proofs against it to change risk assessment methodology and subsequent regulatory policy based on LNT. They point out the remaining uncertainties and the lack of mechanistic explanations of phenomena such as low dose hyperlethality or the adaptive response. In this context, a critical analysis of the available data is necessary. The epidemiological data and the experimental data challenge the validity of the LNT hypothesis for assessing the carcinogenic effect of low doses, but do not allow its exclusion. Therefore, the main criteria for selecting the most reliable dose-effect relationship from a scientific point of view should be based on biological data. Their analysis should help one to understand the current controversy.

  9. Evaluation of the neutron spectrum and dose assessment around the venus reactor.

    Science.gov (United States)

    Coeck, Michèle; Vermeersch, Fernand; Vanhavere, Filip

    2005-01-01

    An assessment of the neutron field near the VENUS reactor is made in order to evaluate the neutron dose to the operators, particularly in an area near the reactor shielding and in the control room. Therefore, a full MCNPX model of the shielding geometry was developed. The source term used in the simulation is derived from a criticality calculation done beforehand. Calculations are compared to routine neutron dose rate measurements and show good agreement. The MCNPX model developed easily allows core adaptations in order to evaluate the effect of future core configuration on the neutron dose to the operators.

  10. Development of a real-time in-vivo dose guided radiotherapy system

    Energy Technology Data Exchange (ETDEWEB)

    Ushino, T.; Smith, M.; Perle, S. [Global Dosimetry Solutions, Irvine, CA (United States); Justus, B.; Huston, A.; Falkenstein, P. [U. S. Naval Research Lab., Optical Physics Branch, Washington, DC (United States); Miller, R.; Coleman, N. [National Cancer Institute, National Institutes of Health, Bethesda, MD (United States)

    2006-07-01

    Accurately assessing the dose to target organs and surrounding tissues in radiation therapy is paramount to achieving maximum treatment efficacy. The goal of radiation therapy is to deliver an optimum dose of ionizing radiation to the target area while at the same time, minimizing the dose to the surrounding tissues. Frequently the target tissue is spatially dynamic and is in close proximity to other tissues whose radiation dose should be minimized to avoid damage. A highly spatially resolved real-time patient dosimetry system will allow radiation therapists and physicians to verify, instantaneously, that the radiation dose is being delivered accurately to the intended target area. There also is a need to accurately assess skin dose in real-time during fluoroscopically-guided interventional procedures to minimize skin damage. A substantial increase in the number of fluoroscopically guided interventional procedures since the 1990 has resulted in an increase in the incidence of radiation-induced skin injuries. This has become a concern to the extent that F.D.A. proposed regulations for monitoring radiation doses delivered by fluoroscopy machines(1). The most likely cause of radiation induced skin injuries are due to particularly long procedures performed at normal dose rates. The availability of real-time radiation dose information will allow the operating physician to appropriately balance the clinical benefit of enhanced visualization versus radiation risks associated with long interventional procedures. Global Dosimetry Solutions (G.D.S.), Inc., a fully accredited world-wide provider of dosimetry services to a wide range of customers including hospitals, medical and dental offices, veterinary clinics, university and national laboratories, nuclear power plants, etc., has developed an in vivo, real-time radiation monitoring technologies for use in radiotherapy and fluoroscopically-guided procedures. The core technologies were developed by Drs. Brian Justus and Alan

  11. Development of internal dose assessment procedure for workers in industries using raw materials containing naturally occurring radioactive materials

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Cheol Kyu; KIm, Yong Geon; Ji, Seung Woo; Kim, Kwang Pyo [College of Engineering, Kyung Hee University, Yongin (Korea, Republic of); Koo, Bon Cheol; Chang, Byung Uck [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2016-09-15

    It is necessary to assess radiation dose to workers due to inhalation of airborne particulates containing naturally occurring radioactive materials (NORM) to ensure radiological safety required by the Natural Radiation Safety Management Act. The objective of this study is to develop an internal dose assessment procedure for workers at industries using raw materials containing natural radionuclides. The dose assessment procedure was developed based on harmonization, accuracy, and proportionality. The procedure includes determination of dose assessment necessity, preliminary dose estimation, airborne particulate sampling and characterization, and detailed assessment of radiation dose. The developed dose assessment procedure is as follows. Radioactivity concentration criteria to determine dose assessment necessity are 10 Bq·g-1 for 40K and 1 Bq·g-1 for the other natural radionuclides. The preliminary dose estimation is performed using annual limit on intake (ALI). The estimated doses are classified into 3 groups (<0.1 mSv, 0.1-0.3 mSv, and >0.3 mSv). Air sampling methods are determined based on the dose estimates. Detailed dose assessment is performed using air sampling and particulate characterization. The final dose results are classified into 4 different levels (<0.1 mSv, 0.1-0.3 mSv, 0.3-1 mSv, and >1 mSv). Proper radiation protection measures are suggested according to the dose level. The developed dose assessment procedure was applied for NORM industries in Korea, including coal combustion, phosphate processing, and monazite handing facilities. The developed procedure provides consistent dose assessment results and contributes to the establishment of optimization of radiological protection in NORM industries.

  12. Environmental dose rate assessment of ITER using the Monte Carlo method

    Directory of Open Access Journals (Sweden)

    Karimian Alireza

    2014-01-01

    Full Text Available Exposure to radiation is one of the main sources of risk to staff employed in reactor facilities. The staff of a tokamak is exposed to a wide range of neutrons and photons around the tokamak hall. The International Thermonuclear Experimental Reactor (ITER is a nuclear fusion engineering project and the most advanced experimental tokamak in the world. From the radiobiological point of view, ITER dose rates assessment is particularly important. The aim of this study is the assessment of the amount of radiation in ITER during its normal operation in a radial direction from the plasma chamber to the tokamak hall. To achieve this goal, the ITER system and its components were simulated by the Monte Carlo method using the MCNPX 2.6.0 code. Furthermore, the equivalent dose rates of some radiosensitive organs of the human body were calculated by using the medical internal radiation dose phantom. Our study is based on the deuterium-tritium plasma burning by 14.1 MeV neutron production and also photon radiation due to neutron activation. As our results show, the total equivalent dose rate on the outside of the bioshield wall of the tokamak hall is about 1 mSv per year, which is less than the annual occupational dose rate limit during the normal operation of ITER. Also, equivalent dose rates of radiosensitive organs have shown that the maximum dose rate belongs to the kidney. The data may help calculate how long the staff can stay in such an environment, before the equivalent dose rates reach the whole-body dose limits.

  13. Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico

    Science.gov (United States)

    Luevano-Gurrola, Sergio; Perez-Tapia, Angelica; Pinedo-Alvarez, Carmelo; Carrillo-Flores, Jorge; Montero-Cabrera, Maria Elena; Renteria-Villalobos, Marusia

    2015-01-01

    Determining ionizing radiation in a geographic area serves to assess its effects on a population’s health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h−1. At the same sites, 48 soil samples were taken to obtain the activity concentrations of 226Ra, 232Th and 40K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h−1. Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg−1, for 226Ra, 232Th and 40K, respectively. From the analysis, the spatial distribution of 232Th, 226Ra and 40K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize. PMID:26437425

  14. RADIATION HYGIENIC MONITORING AND ASSESSMENT OF POPULATION DOSES IN RADIOACTIVELY CONTAMINATED AREAS OF TULA REGION

    Directory of Open Access Journals (Sweden)

    T. M. Chichura

    2016-01-01

    Full Text Available The goal. The analyses of radiation hygienic monitoring conducted in Tula region territories affected by the Chernobyl NPP accident regarding cesium-137 and strontium- 90 in the local foodstuffs and the analyses of populational annual effective dose. The materials and methods. The survey was conducted in Tula Region since 1997 to 2015. Over that period, more than fifty thousand samples of the main foodstuffs from the post-Chernobyl contaminated area were analyzed. Simultaneously with that, the external gamma - radiation dose rate was measured in the fixed control points. The dynamics of cesium -137 and strontium-90 content in foodstuffs were assessed along with the maximum values of the mean annual effective doses to the population and the contribution of the collective dose from medical exposures into the structure of the annual effective collective dose to the population. The results. The amount of cesium-137 and strontium -90 in the local foodstuffs was identified. The external gamma- radiation dose rate values were found to be stable and not exceeding the natural fluctuations range typical for the middle latitudes of Russia’s European territory. The maximum mean annual effective dose to the population reflects the stable radiation situation and does not exceed the permissible value of 1 mSv. The contribution of the collective dose from medical exposures of the population has been continuously reducing as well as the average individual dose to the population per one medical treatment under the annual increase of the medical treatments quantities. The conclusion. There is no exceedance of the admissible levels of cesium-137 and strontium- 90 content in the local foodstuffs. The mean annual effective dose to the population has decreased which makes it possible to transfer the settlements affected by the Chernobyl NPP accident to normal life style. This is covered by the draft concept of the settlements’ transfer to normal life style.

  15. Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico.

    Science.gov (United States)

    Luevano-Gurrola, Sergio; Perez-Tapia, Angelica; Pinedo-Alvarez, Carmelo; Carrillo-Flores, Jorge; Montero-Cabrera, Maria Elena; Renteria-Villalobos, Marusia

    2015-09-30

    Determining ionizing radiation in a geographic area serves to assess its effects on a population's health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h(-1). At the same sites, 48 soil samples were taken to obtain the activity concentrations of (226)Ra, (232)Th and (40)K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h(-1). Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg(-1), for (226)Ra, (232)Th and (40)K, respectively. From the analysis, the spatial distribution of (232)Th, (226)Ra and (40)K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize.

  16. Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico

    Directory of Open Access Journals (Sweden)

    Sergio Luevano-Gurrola

    2015-09-01

    Full Text Available Determining ionizing radiation in a geographic area serves to assess its effects on a population’s health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h−1. At the same sites, 48 soil samples were taken to obtain the activity concentrations of 226Ra, 232Th and 40K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h−1. Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg−1, for 226Ra, 232Th and 40K, respectively. From the analysis, the spatial distribution of 232Th, 226Ra and 40K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize.

  17. Silent aspiration: results of 2,000 video fluoroscopic evaluations.

    Science.gov (United States)

    Garon, Bernard R; Sierzant, Tess; Ormiston, Charles

    2009-08-01

    The purpose of this retrospective study of aspiration and the lack of a protective cough reflex at the vocal folds (silent aspiration) was to increase the awareness of nursing staffs of the diagnostic pathology groups associated with silent aspiration. Of the 2,000 patients evaluated in this study, 51% aspirated on the video fluoroscopic evaluation. Of the patients who aspirated, 55% had no protective cough reflex (silent aspiration). The diagnostic pathology groups with the highest rates of silent aspiration were brain cancer, brainstem stroke, head-neck cancer, pneumonia, dementia/Alzheimer, chronic obstructive lung disease, seizures, myocardial infarcts, neurodegenerative pathologies, right hemisphere stroke, closed head injury, and left hemisphere stroke. It is of high concern that the diagnostic groups identified in this research as having the highest risk of silent aspiration be viewed as "red-flag" patients by the nursing staff caring for them. Early nursing dysphagia screens, with close attention to the clinical symptoms associated with silent aspiration, and early referral for formal dysphagia evaluation are stressed.

  18. Ultrasound and fluoroscopic images fusion by autonomous ultrasound probe detection.

    Science.gov (United States)

    Mountney, Peter; Ionasec, Razvan; Kaizer, Markus; Mamaghani, Sina; Wu, Wen; Chen, Terrence; John, Matthias; Boese, Jan; Comaniciu, Dorin

    2012-01-01

    New minimal-invasive interventions such as transcatheter valve procedures exploit multiple imaging modalities to guide tools (fluoroscopy) and visualize soft tissue (transesophageal echocardiography (TEE)). Currently, these complementary modalities are visualized in separate coordinate systems and on separate monitors creating a challenging clinical workflow. This paper proposes a novel framework for fusing TEE and fluoroscopy by detecting the pose of the TEE probe in the fluoroscopic image. Probe pose detection is challenging in fluoroscopy and conventional computer vision techniques are not well suited. Current research requires manual initialization or the addition of fiducials. The main contribution of this paper is autonomous six DoF pose detection by combining discriminative learning techniques with a fast binary template library. The pose estimation problem is reformulated to incrementally detect pose parameters by exploiting natural invariances in the image. The theoretical contribution of this paper is validated on synthetic, phantom and in vivo data. The practical application of this technique is supported by accurate results (< 5 mm in-plane error) and computation time of 0.5s.

  19. Percutaneous vertebroplasty: optimizing the procedure after treatment of 250 vertebral levels under fluoroscopic guidance.

    Science.gov (United States)

    Pedicelli, A; Rollo, M; Piano, M; Grattacaso, G; Colosimo, C; Bonomo, L

    2009-10-01

    Percutaneous vertebroplasty (PVP) is a minimally invasive treatment for symptomatic vertebral compression fractures (VCFs). The aim of this study was to assess the effectiveness, complications and progress of results of PVP optimized in terms of technique, costs, time and strategic protocol after 3 years of procedures performed under fluoroscopic guidance alone. We treated 250 VCFs in 120 consecutive patients after assessing clinical and radiological indications. The effectiveness of the procedure was determined by statistical analysis of numerical scores for pain, mobility and drug consumption before and after treatment. No major complications and only three minor complications occurred. Clinically relevant improved mobility and reduction of pain and analgesics were observed, with overall significant results (p<0.0001) in all patients at 24 h after PVP and in 83 available patients at 6 months. A total of five asymptomatic refractures of cemented vertebrae and 14 new symptomatic vertebral fractures at different levels were observed between 1 and 10 months after the procedure. PVP is a safe, rapid, effective and costeffective therapy for VCFs, requiring only brief hospital admission and with long-lasting clinical results, when performed under good-quality radiological guidance, when correct indications are respected and when it is associated with rehabilitation therapy in the follow-up. It is a valid alternative to conservative therapy, which is burdened by high healthcare costs and often requires long-term immobilisation of frail and elderly patients at risk of clinical complications.

  20. Effect of low-dose CT and iterative reconstruction on trabecular bone microstructure assessment

    Science.gov (United States)

    Kopp, Felix K.; Baum, Thomas; Nasirudin, Radin A.; Mei, Kai; Garcia, Eduardo G.; Burgkart, Rainer; Rummeny, Ernst J.; Bauer, Jan S.; Noël, Peter B.

    2016-03-01

    The trabecular bone microstructure is an important factor in the development of osteoporosis. It is well known that its deterioration is one effect when osteoporosis occurs. Previous research showed that the analysis of trabecular bone microstructure enables more precise diagnoses of osteoporosis compared to a sole measurement of the mineral density. Microstructure parameters are assessed on volumetric images of the bone acquired either with high-resolution magnetic resonance imaging, high-resolution peripheral quantitative computed tomography or high-resolution computed tomography (CT), with only CT being applicable to the spine, which is one of clinically most relevant fracture sites. However, due to the high radiation exposure for imaging the whole spine these measurements are not applicable in current clinical routine. In this work, twelve vertebrae from three different donors were scanned with standard and low radiation dose. Trabecular bone microstructure parameters were assessed for CT images reconstructed with statistical iterative reconstruction (SIR) and analytical filtered backprojection (FBP). The resulting structure parameters were correlated to the biomechanically determined fracture load of each vertebra. Microstructure parameters assessed for low-dose data reconstructed with SIR significantly correlated with fracture loads as well as parameters assessed for standard-dose data reconstructed with FBP. Ideal results were achieved with low to zero regularization strength yielding microstructure parameters not significantly different from those assessed for standard-dose FPB data. Moreover, in comparison to other approaches, superior noise-resolution trade-offs can be found with the proposed methods.

  1. CTDI versus new AAPM metrics to assess doses in CT: a case study

    Energy Technology Data Exchange (ETDEWEB)

    Campelo, M.C.S., E-mail: maria.macalidi@gmail.com [Pontificia Universidade Catolica de Sao Paulo (PUC-SP), SP (Brazil); Silva, M.C., E-mail: marciac.silvag@gmail.com [Hospital Israelita Albert Einstein (HIAE), Sao Paulo, SP (Brazil); Terini, R.A., E-mail: ricardoaterini@gmail.com [Universidade de Sao Paulo (LABEND/USP), SP (Brazil). Laboratorio de Ensaios Nao-Destrutivos

    2016-07-01

    In modern CT, CTDI100 measurements would underestimate accumulated dose at the gantry center. AAPM TG 111 report proposed improved metrics for CT dosimetry, mainly for helical and wide beam width scanning. In this study, a methodology to assess CT dose, inspired on TG 111, was applied. Dosimeters were firstly calibrated in lab in beams like those utilized clinically. Using a reference 0.6cc Farmer chamber, two CT “pencil” chambers were calibrated in P{sub KL} by substitution method. Results showed differences ≤ 2% in the calibration coefficients, for three collimation apertures. A small 0.6cc chamber was calibrated in air kerma with this setup, without any collimator. After this, in a private Brazilian hospital, the small chamber was applied in dosimetry tests of a CT scanner, according to TG 111, determining Dose profiles and Equilibrium dose free-in-air (D{sub eq,air}) for some protocols and pitch values. Results showed that D{sub eq,air} increased when reducing pitch and Equilibrium dose-pitch product free in air (p.D{sub eq,air}) remain constant. In measurements with a 450mm CT phantom, differences between Planar Average Equilibrium Dose (D{sub eq,p}) and CTDIvol ranged between 30-37%. This occurs because CTDI{sub vol} cannot include dose profile 'tail' contribution, caused by scattering in phantom, especially for wide beam widths. (author)

  2. Additional dose assessment from the activation of high-energy linear accelerators used in radiation therapy

    Directory of Open Access Journals (Sweden)

    Ateia Embarka

    2008-01-01

    Full Text Available It is well known that medical linear accelerators generate activation products when operated above certain electron (photon energies. The aim of the present work is to assess the activation behavior of a medium-energy radiotherapy linear accelerator by applying in situ gamma-ray spectrometry and dose measurements, and to estimate the additional dose to radiotherapy staff on the basis of these results. Spectral analysis was performed parallel to dose rate measurements in the isocenter of the linear accelerator, immediately after the termination of irradiation. The following radioisotopes were detected by spectral analysis: 28Al, 62Cu, 56Mn, 64Cu, 187W, and 57Ni. The short-lived isotopes such as 28Al and 62Cu are the most important factors of the clinical routine, while the contribution to the radiation dose of medium-lived isotopes such as 56Mn, 57Ni, 64Cu, and 187W increases during the working day. Measured dose rates at the isocenter ranged from 2.2 µSv/h to 10 µSv/h in various measuring points of interest for the members of the radiotherapy staff. Within the period of 10 minutes, the dose rate decreased to values of 0.8 µSv/h. According to actual workloads in radiotherapy departments, a realistic exposure scenario was set, resulting in a maximal additional annual whole body dose to the radiotherapy staff of about 3.5 mSv.

  3. Landscape dose conversion factors used in the safety assessment SR-Site

    Energy Technology Data Exchange (ETDEWEB)

    Avila, Rodolfo; Ekstroem, Per-Anders; Aastrand, Per-Gustav (Facilia AB (Sweden))

    2010-12-15

    In this report two types of Dose Conversion Factors have been derived: i) a Landscape Dose Conversion Factor (LDF) that is applicable to continuous long-term releases to the biosphere at a constant rate, and ii) a Landscape Dose Conversion Factor for pulse releases (LDF pulse) that is applicable to a radionuclide release that reaches the biosphere in a pulse within years to hundreds of years. In SR-Site these Dose Factors are multiplied with modelled release rates or pulse releases from the geosphere to obtain dose estimates used in assessment of compliance with the regulatory risk criterion. The LDFs were calculated for three different periods of the reference glacial cycle; a period of submerged conditions following the deglaciation, the temperate period, and a prolonged period of periglacial conditions. Additionally, LDFs were calculated for the global warming climate case. The LDF pulse was calculated only for temperate climate conditions. The LDF and LDF pulse can be considered as Best Estimate values, which can be used in calculations of Best Estimate values of doses to a representative individual of the most exposed group from potential releases from a future repository. A systematic analysis of the effects of system, model and parameter uncertainties on the LDFs has been carried out. This analysis has shown that the use of the derived LDF would lead to cautious or realistic dose estimates. The models and methods that were used for derivation of the LDFs and LDF pulse are also described in this report

  4. Preclinical assessment of HIV vaccines and microbicides by repeated low-dose virus challenges.

    Directory of Open Access Journals (Sweden)

    Roland R Regoes

    2005-08-01

    Full Text Available BACKGROUND: Trials in macaque models play an essential role in the evaluation of biomedical interventions that aim to prevent HIV infection, such as vaccines, microbicides, and systemic chemoprophylaxis. These trials are usually conducted with very high virus challenge doses that result in infection with certainty. However, these high challenge doses do not realistically reflect the low probability of HIV transmission in humans, and thus may rule out preventive interventions that could protect against "real life" exposures. The belief that experiments involving realistically low challenge doses require large numbers of animals has so far prevented the development of alternatives to using high challenge doses. METHODS AND FINDINGS: Using statistical power analysis, we investigate how many animals would be needed to conduct preclinical trials using low virus challenge doses. We show that experimental designs in which animals are repeatedly challenged with low doses do not require unfeasibly large numbers of animals to assess vaccine or microbicide success. CONCLUSION: Preclinical trials using repeated low-dose challenges represent a promising alternative approach to identify potential preventive interventions.

  5. The Thule accident: Assessment of radiation doses from terrestrial radioactive contamination

    Energy Technology Data Exchange (ETDEWEB)

    Ulbak, K. (National Institute of Radiation Protection, Herlev (Denmark))

    2011-12-15

    Risoe DTU has carried out research on the terrestrial contamination in the Thule area after the radioactive contents of four nuclear weapons were dispersed following the crash of an American B-52 bomber in 1968. The results of Risoe DTU's studies are described in the report Thule-2007 - Investigation of radioactive pollution on land, which covers all measurements that were carried out on land in Thule in the years 2003, 2006, 2007 and 2008. The present report uses Risoe DTU's report as a basis for assessing radiation doses and consequently the risk for individuals as a result of terrestrial radioactive contamination in the Thule area. The assessment of radiation doses involves a number of conservative assumptions, estimates, and measurements, all of which are subject to considerable uncertainty. In some cases, models have been used based on experiences from other contaminated areas elsewhere in the world, which are subject to climatic and other conditions that diverge from those in the Thule area. The calculated doses are thus associated with considerable uncertainty, which must be taken into account when the results are used for comparison and when the risks of staying in the Thule area are assessed. It has therefore been chosen to provide the assessed radiation doses in the form of indicative orders of magnitude, which are applicable to everyone who might stay in the area, across various age groups. If the estimated doses in this report are combined with the National Institute of Radiation Protection's recommended reference level for contamination as a result of the Thule Accident of 1 mSv/year, the assessed magnitudes of radiation doses for inhalation and ingestion as exposure pathways are many orders of magnitude below the reference level (10,000-10 million times smaller). The wound contamination exposure pathway has a magnitude of radiation dose that is smaller than the reference level by a factor of 10-1000, and it should be recalled that the

  6. A A field test for extremity dose assessment during outages at Korean nuclear power plants.

    Science.gov (United States)

    Kim, Hee Geun; Kong, Tae Young

    2013-05-01

    During maintenance on the water chamber of a steam generator, the pressuriser heater and the pressure tube feeder in nuclear power plants, workers are likely to receive high radiation doses due to the severe workplace conditions. In particular, it is expected that workers' hands would receive the highest radiation doses because of their contact with the radioactive materials. In this study, field tests for extremity dose assessments in radiation workers undertaking contact tasks with high radiation doses were conducted during outages at pressurised water reactors and pressurised heavy water reactors in Korea. In the test, the radiation workers were required to wear additional thermoluminescent dosemeters (TLDs) on their backs and wrists and an extremity dosemeter on the finger, as well as a main TLD on the chest while performing the maintenance tasks.

  7. SU-F-P-19: Fetal Dose Estimate for a High-Dose Fluoroscopy Guided Intervention Using Modern Data Tools

    Energy Technology Data Exchange (ETDEWEB)

    Moirano, J [University of Washington, Seattle, WA (United States)

    2016-06-15

    Purpose: An accurate dose estimate is necessary for effective patient management after a fetal exposure. In the case of a high-dose exposure, it is critical to use all resources available in order to make the most accurate assessment of the fetal dose. This work will demonstrate a methodology for accurate fetal dose estimation using tools that have recently become available in many clinics, and show examples of best practices for collecting data and performing the fetal dose calculation. Methods: A fetal dose estimate calculation was performed using modern data collection tools to determine parameters for the calculation. The reference point air kerma as displayed by the fluoroscopic system was checked for accuracy. A cumulative dose incidence map and DICOM header mining were used to determine the displayed reference point air kerma. Corrections for attenuation caused by the patient table and pad were measured and applied in order to determine the peak skin dose. The position and depth of the fetus was determined by ultrasound imaging and consultation with a radiologist. The data collected was used to determine a normalized uterus dose from Monte Carlo simulation data. Fetal dose values from this process were compared to other accepted calculation methods. Results: An accurate high-dose fetal dose estimate was made. Comparison to accepted legacy methods were were within 35% of estimated values. Conclusion: Modern data collection and reporting methods ease the process for estimation of fetal dose from interventional fluoroscopy exposures. Many aspects of the calculation can now be quantified rather than estimated, which should allow for a more accurate estimation of fetal dose.

  8. Assessment of patient doses and image quality in X-ray diagnostics in Norway

    Energy Technology Data Exchange (ETDEWEB)

    Olerud, H.M.

    1998-06-01

    Results from other industrialized countries indicate that the annual number of diagnostic procedures approaches one for every member of the population, and in many cases the individual radiation doses are higher than from any other human activity. Furthermore, the doses to patients for the same type of examination differ widely from place to place, suggesting that there is a considerable potential for dose reduction. This motivated an investigation of the diagnostic use of X-rays in Norway. The trends in the number of X-ray examinations performed annually have been studied. The patient doses (all diagnostics) and image quality (mammography and computed tomography) have been assessed for various radiological procedures. This form the basis for the assessment of total collective effective dose (CED) from X-rays in Norway, and further risk estimates. The radiological practice has then been evaluated according to the radiation protection principles of justification and optimisation. Based on the 1993 examination frequency, the total CED was assessed to 3400 manSv (0.78 mSv/inhabitant). It is estimated that this radiation burden may cause about 100 excess cancer deaths annually. The frequency of CT examination has doubled every fifth year, and did in 1993 represent 7% of the total number of examinations and 30% of the total CED. 129 refs.

  9. ACUTRI a computer code for assessing doses to the general public due to acute tritium releases

    CERN Document Server

    Yokoyama, S; Noguchi, H; Ryufuku, S; Sasaki, T

    2002-01-01

    Tritium, which is used as a fuel of a D-T burning fusion reactor, is the most important radionuclide for the safety assessment of a nuclear fusion experimental reactor such as ITER. Thus, a computer code, ACUTRI, which calculates the radiological impact of tritium released accidentally to the atmosphere, has been developed, aiming to be of use in a discussion of licensing of a fusion experimental reactor and an environmental safety evaluation method in Japan. ACUTRI calculates an individual tritium dose based on transfer models specific to tritium in the environment and ICRP dose models. In this calculation it is also possible to analyze statistically on meteorology in the same way as a conventional dose assessment method according to the meteorological guide of the Nuclear Safety Commission of Japan. A Gaussian plume model is used for calculating the atmospheric dispersion of tritium gas (HT) and/or tritiated water (HTO). The environmental pathway model in ACUTRI considers the following internal exposures: i...

  10. Benchmark dose profiles for joint-action continuous data in quantitative risk assessment.

    Science.gov (United States)

    Deutsch, Roland C; Piegorsch, Walter W

    2013-09-01

    Benchmark analysis is a widely used tool in biomedical and environmental risk assessment. Therein, estimation of minimum exposure levels, called benchmark doses (BMDs), that induce a prespecified benchmark response (BMR) is well understood for the case of an adverse response to a single stimulus. For cases where two agents are studied in tandem, however, the benchmark approach is far less developed. This paper demonstrates how the benchmark modeling paradigm can be expanded from the single-agent setting to joint-action, two-agent studies. Focus is on continuous response outcomes. Extending the single-exposure setting, representations of risk are based on a joint-action dose-response model involving both agents. Based on such a model, the concept of a benchmark profile-a two-dimensional analog of the single-dose BMD at which both agents achieve the specified BMR-is defined for use in quantitative risk characterization and assessment.

  11. Committed dose assessment based on background outdoor gamma exposure in Chihuahua City, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Luevano G, S.; Perez T, A.; Pinedo A, C.; Renteria V, M. [Universidad Autonoma de Chihuahua, Facultad de Zootecnia y Ecologia, Perif. Francisco R. Almada Km 1, 31415 Chihuahua, Chih. (Mexico); Carrillo F, J.; Montero C, M. E., E-mail: mrenteria@uach.mx [Centro de Investigacion en Materiales Avanzados, Miguel de Cervantes 120, 31136 Chihuahua, Chih. (Mexico)

    2015-10-15

    Full text: Determining ionizing radiation in a geographic area serves to assess its effects on populations health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the committed dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, annual effective dose, and the lifetime cancer risk, 48 sampling points were randomly selected along the Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Muller counter. At the same sites, 48 soil samples were taken to obtain the activity concentrations of {sup 226}Ra, {sup 232}Th, {sup 40}K and their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Outdoor gamma dose rates ranged from 56 to 193 n Gy h{sup -1}. Results indicated that lifetime effective dose to inhabitants of Chihuahua City is in average of 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of activity concentrations in soil were 51.8, 73.1, and 1096.5 Bq kg{sup -1}, of {sup 226}Ra, {sup 232}Th and {sup 40}K, respectively. From the analysis of the spatial distribution of {sup 232}Th, {sup 226}Ra, and {sup 40}K is to north, to north-center, and to south of city, respectively. In conclusion, natural background gamma dose received by inhabitants of Chihuahua City is high and mainly due to geological characteristics of the zone. (Author)

  12. Impact of acquired immunity and dose-dependent probability of illness on quantitative microbial risk assessment

    NARCIS (Netherlands)

    Havelaar, A. H.; Swart, A. N.

    2014-01-01

    Dose-response models in microbial risk assessment consider two steps in the process ultimately leading to illness: from exposure to (asymptomatic) infection, and from infection to (symptomatic) illness. Most data and theoretical approaches are available for the exposure-infection step; the infection

  13. Clinical evaluation of a dose monitoring software tool based on Monte Carlo Simulation in assessment of eye lens doses for cranial CT scans

    Energy Technology Data Exchange (ETDEWEB)

    Guberina, Nika; Suntharalingam, Saravanabavaan; Nassenstein, Kai; Forsting, Michael; Theysohn, Jens; Wetter, Axel; Ringelstein, Adrian [University Hospital Essen, Institute of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany)

    2016-10-15

    The aim of this study was to verify the results of a dose monitoring software tool based on Monte Carlo Simulation (MCS) in assessment of eye lens doses for cranial CT scans. In cooperation with the Federal Office for Radiation Protection (Neuherberg, Germany), phantom measurements were performed with thermoluminescence dosimeters (TLD LiF:Mg,Ti) using cranial CT protocols: (I) CT angiography; (II) unenhanced, cranial CT scans with gantry angulation at a single and (III) without gantry angulation at a dual source CT scanner. Eye lens doses calculated by the dose monitoring tool based on MCS and assessed with TLDs were compared. Eye lens doses are summarized as follows: (I) CT angiography (a) MCS 7 mSv, (b) TLD 5 mSv; (II) unenhanced, cranial CT scan with gantry angulation, (c) MCS 45 mSv, (d) TLD 5 mSv; (III) unenhanced, cranial CT scan without gantry angulation (e) MCS 38 mSv, (f) TLD 35 mSv. Intermodality comparison shows an inaccurate calculation of eye lens doses in unenhanced cranial CT protocols at the single source CT scanner due to the disregard of gantry angulation. On the contrary, the dose monitoring tool showed an accurate calculation of eye lens doses at the dual source CT scanner without gantry angulation and for CT angiography examinations. The dose monitoring software tool based on MCS gave accurate estimates of eye lens doses in cranial CT protocols. However, knowledge of protocol and software specific influences is crucial for correct assessment of eye lens doses in routine clinical use. (orig.)

  14. Development of environmental dose assessment system (EDAS) code of PC version

    Energy Technology Data Exchange (ETDEWEB)

    Taki, Mitsumasa; Kikuchi, Masamitsu; Kobayashi, Hideo; Yamaguchi, Takenori [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-05-01

    A computer code (EDAS) was developed to assess the public dose for the safety assessment to get the license of nuclear reactor operation. This code system is used for the safety analysis of public around the nuclear reactor in normal operation and severe accident. This code was revised and composed for personal computer user according to the Nuclear Safety Guidelines reflected the ICRP1990 recommendation. These guidelines are revised by Nuclear Safety Commission on March, 2001, which are 'Weather analysis guideline for the safety assessment of nuclear power reactor', 'Public dose around the facility assessment guideline corresponding to the objective value for nuclear power light water reactor' and 'Public dose assessment guideline for safety review of nuclear power light water reactor'. This code has been already opened for public user by JAERI, and English version code and user manual are also prepared. This English version code is helpful for international cooperation concerning the nuclear safety assessment with JAERI. (author)

  15. Radioactivity in food and the environment: calculations of UK radiation doses using integrated assessment methods

    Energy Technology Data Exchange (ETDEWEB)

    Camplin, W C; Brownless, G P; Round, G D; Winpenny, K; Hunt, G J [Centre for Environment, Fisheries and Aquaculture Science, CEFAS Laboratory, Lowestoft (United Kingdom)

    2002-12-01

    A new method for estimating radiation doses to UK critical groups is proposed for discussion. Amongst others, the Food Standards Agency (FSA) and the Scottish Environment Protection Agency (SEPA) undertake surveillance of UK food and the environment as a check on the effect of discharges of radioactive wastes. Discharges in gaseous and liquid form are made under authorisation by the Environment Agency and SEPA under powers in the Radioactive Substance Act. Results of surveillance by the FSA and SEPA are published in the Radioactivity in Food and the Environment (RIFE) report series. In these reports, doses to critical groups are normally estimated separately for gaseous and liquid discharge pathways. Simple summation of these doses would tend to overestimate doses actually received. Three different methods of combining the effects of both types of discharge in an integrated assessment are considered and ranked according to their ease of application, transparency, scientific rigour and presentational issues. A single integrated assessment method is then chosen for further study. Doses are calculated for surveillance data for the calendar year 2000 and compared with those from the existing RIFE method.

  16. Fluoroscopically-Guided Posterior Approach for Shoulder Magnetic Resonance Arthrography: Comparison with Conventional Anterior Approach

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Koun J.; Ha, Doo Hoe; Lee, Sang Min [Dept. of Radiology, CHA Budang Medical Center, CHA University College of Medicine, Seongnam (Korea, Republic of)

    2011-10-15

    To prospectively evaluate the usefulness of the fluoroscopically-guided posterior approach compared with the anterior approach for shoulder magnetic resonance(MR) arthrography. Institutional review board approval and informed consent were obtained. Among 60 shoulder MR arthrographies performed on 59 patients with symptomatic shoulders, an intra-articular injection was performed (30 cases using the anterior approach and 30 using the posterior approach). Procedure-related pain was assessed by using a 5 score visual analogue scale (VAS). Depth of the puncture and standardized depth of puncture by body mass index (BMI) were recorded. The contrast leakage along the course of the puncture was evaluated by reviewing the MR. The statistical analyses included the Mann-Whitney U and Kruskal-Wallis test. There was no significant difference in VAS scores between the anterior and posterior groups (1.77 {+-} 1.10 vs. 1.80 {+-} 0.96). Depth of puncture and standardized depth of puncture by BMI were significantly shorter in the posterior group than those in the anterior group (4.4 {+-} 0.8 cm and 1.8 {+-} 0.3 cm vs. 6.6 {+-} 0.9 cm and 2.8 {+-} 0.4 cm, p < 0.001), respectively. The incidence of contrast leakage was more frequent in the posterior group (p = 0.003). The posterior approach will be useful in shoulder MR arthrography with a suspected anterior pathology, a postoperative follow-up study or obese patient.

  17. Role Guided Intraperitoneal Port-A-Cath Insertion in The Managment of Cancer Ovary of Fluoroscopic

    Directory of Open Access Journals (Sweden)

    Ahmed H Soliman *, Saad Ali Abd-Rabou *, Maged Abou Seada *,

    2013-07-01

    Full Text Available Introduction : The use of intraperitoneal (IP chemotherapy as a treatment for ovarian cancer has been demonstrated to result in improved survival. Aim of the work: The aim of this work is to evaluate the applicability and efficacy of fluoroscopic placed intraperitoneal port-A-cath and to assess the response rate to intraperitoneal chemotherapy in cases of ovarian carcinoma .Methods: The studied group included ,22 female patients with malignant ovarian cancer whom referred from gynecological surgery and gynecological oncology units to the Vascular and Interventional Radiology Unit, Ain Shams University Hospitals, for peritoneal port-A-cath application. All the patients were known cases of either primary or recurrent ovarian cancer , underwent cytoreductive surgery and referred to us .Results: Intraperitoneal port-A-cath with the aid of fluoroscopy showed highest technical success ( 91.9% and lowest complication rate on the long run compared to other methods of peritoneal access . Patients with cancer ovary showed significant improvement of the disease process denoted by changes in the degree of ascites , peritoneal nodules and tumor marker level after receiving combined IV/ IP chemotherapy. Conclusion: Port catheters proved to be the most safe method of long term access to the peritoneal cavity with the lowest complication rate compared to other methods of access to the peritoneal cavity

  18. Fine needle aspiration of focal lung lesion under CT fluoroscopic guidance

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Hae Jeong; Shin, Hyun Joon; Choi, Young Chil; Park, Sang Woo; Yi, Jeong Geun; Park, Jeong Hee [College of Medicine, Konkuk University, Seoul (Korea, Republic of); Jin, Yong Hyun [Sung Ae Hospital, Seoul (Korea, Republic of)

    2006-07-15

    We wanted to assess the efficacy of using CT fluoroscopy during Fine Needle Aspiration (FNA) for focal lung lesion. We retrospectively reviewed 22 patients who had undergone FNA under CT fluoroscopic guidance. The final diagnosis of focal lung lesion was based on surgery, the results of biopsy taken from another site or the clinical diagnosis with imaging follow-up. We reviewed the imaging and recorded the location of the lesion, the lesion size and the depth from the puncture site. In 24 cases of 22 patients, 16 lesions were benign and 8 were malignant. The sensitivity and specificity for malignant lesions were 100%, and 75%, respectively. The mean size of the malignant lesions was 3.75 {+-} 1.68 cm, and that of the benign lesion was 3.05 {+-} 2.98 cm. The mean depth of the lesion divided by the size was 1.85 {+-} 1.09 for 20 lesions of the correct result group and 3.13 {+-} 1.73 for 4 lesions of the incorrect result group; the difference between the two groups was statistically different ({rho} = 0.030). The complications after FNA were pneumothoraces in three cases and parenchymal hemorrhage in one case, but no significant complication was noted after the procedures. We could perform the FNA accurately and safely under CT fluoroscopy guidance, so this technique can be used for FNA of focal lung lesion for obtaining a correct result with fewer complications.

  19. Assessment of radiation dose in nuclear cardiovascular imaging using realistic computational models

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Tianwu [Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva 4 CH-1211 (Switzerland); Lee, Choonsik [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institute of Health, Bethesda, Maryland 20852 (United States); Bolch, Wesley E. [Departments of Nuclear and Radiological and Biomedical Engineering, University of Florida, Gainesville, Florida 32611 (United States); Zaidi, Habib, E-mail: habib.zaidi@hcuge.ch [Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva 4 CH-1211 (Switzerland); Geneva Neuroscience Center, Geneva University, Geneva CH-1205 (Switzerland); Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen 9700 RB (Netherlands)

    2015-06-15

    Purpose: Nuclear cardiology plays an important role in clinical assessment and has enormous impact on the management of a variety of cardiovascular diseases. Pediatric patients at different age groups are exposed to a spectrum of radiation dose levels and associated cancer risks different from those of adults in diagnostic nuclear medicine procedures. Therefore, comprehensive radiation dosimetry evaluations for commonly used myocardial perfusion imaging (MPI) and viability radiotracers in target population (children and adults) at different age groups are highly desired. Methods: Using Monte Carlo calculations and biological effects of ionizing radiation VII model, we calculate the S-values for a number of radionuclides (Tl-201, Tc-99m, I-123, C-11, N-13, O-15, F-18, and Rb-82) and estimate the absorbed dose and effective dose for 12 MPI radiotracers in computational models including the newborn, 1-, 5-, 10-, 15-yr-old, and adult male and female computational phantoms. Results: For most organs, {sup 201}Tl produces the highest absorbed dose whereas {sup 82}Rb and {sup 15}O-water produce the lowest absorbed dose. For the newborn baby and adult patient, the effective dose of {sup 82}Rb is 48% and 77% lower than that of {sup 99m}Tc-tetrofosmin (rest), respectively. Conclusions: {sup 82}Rb results in lower effective dose in adults compared to {sup 99m}Tc-labeled tracers. However, this advantage is less apparent in children. The produced dosimetric databases for various radiotracers used in cardiovascular imaging, using new generation of computational models, can be used for risk-benefit assessment of a spectrum of patient population in clinical nuclear cardiology practice.

  20. Radiation dose assessment in a 320-detector-row CT scanner used in cardiac imaging

    Energy Technology Data Exchange (ETDEWEB)

    Goma, Carles; Ruiz, Agustin; Jornet, Nuria; Latorre, Artur; Pallerol, Rosa M.; Carrasco, Pablo; Eudaldo, Teresa; Ribas, Montserrat [Servei de Radiofisica i Radioproteccio, Hospital de la Santa Creu i Sant Pau, Sant Antoni Maria Claret 167, 08025 Barcelona (Spain)

    2011-03-15

    Purpose: In the present era of cone-beam CT scanners, the use of the standardized CTDI{sub 100} as a surrogate of the idealized CTDI is strongly discouraged and, consequently, so should be the use of the dose-length product (DLP) as an estimate of the total energy imparted to the patient. However, the DLP is still widely used as a reference quantity to normalize the effective dose for a given scan protocol mainly because the CTDI{sub 100} is an easy-to-measure quantity. The aim of this article is therefore to describe a method for radiation dose assessment in large cone-beam single axial scans, which leads to a straightforward estimation of the total energy imparted to the patient. The authors developed a method accessible to all medical physicists and easy to implement in clinical practice in an attempt to update the bridge between CT dosimetry and the estimation of the effective dose. Methods: The authors used commercially available material and a simple mathematical model. The method described herein is based on the dosimetry paradigm introduced by the AAPM Task Group 111. It consists of measuring the dose profiles at the center and the periphery of a long body phantom with a commercial solid-state detector. A weighted dose profile is then calculated from these measurements. To calculate the CT dosimetric quantities analytically, a Gaussian function was fitted to the dose profile data. Furthermore, the Gaussian model has the power to condense the z-axis information of the dose profile in two parameters: The single-scan central dose, f(0), and the width of the profile, {sigma}. To check the energy dependence of the solid-state detector, the authors compared the dose profiles to measurements made with a small volume ion chamber. To validate the overall method, the authors compared the CTDI{sub 100} calculated analytically to the measurement made with a 100 mm pencil ion chamber. Results: For the central and weighted dose profiles, the authors found a good

  1. Assessment of the occupational eye lens dose for clinical staff in interventional radiology, cardiology and neuroradiology.

    Science.gov (United States)

    Omar, Artur; Kadesjö, Nils; Palmgren, Charlotta; Marteinsdottir, Maria; Segerdahl, Tony; Fransson, Annette

    2017-03-20

    In accordance with recommendations by the International Commission on Radiological Protection, the current European Basic Safety Standards has adopted a reduced occupational eye lens dose limit of 20 mSv yr(-1). The radiation safety implications of this dose limit is of concern for clinical staff that work with relatively high dose x-ray angiography and interventional radiology. Presented in this work is a thorough assessment of the occupational eye lens dose based on clinical measurements with active personal dosimeters worn by staff during various types of procedures in interventional radiology, cardiology and neuroradiology. Results are presented in terms of the estimated equivalent eye lens dose for various medical professions. In order to compare the risk of exceeding the regulatory annual eye lens dose limit for the widely different clinical situations investigated in this work, the different medical professions were separated into categories based on their distinct work pattern: staff that work (a) regularly beside the patient, (b) in proximity to the patient and (c) typically at a distance from the patient. The results demonstrate that the risk of exceeding the annual eye lens dose limit is of concern for staff category (a), i.e. mainly the primary radiologist/cardiologist. However, the results also demonstrate that the risk can be greatly mitigated if radiation protection shields are used in the clinical routine. The results presented in this work cover a wide range of clinical situations, and can be used as a first indication of the risk of exceeding the annual eye lens dose limit for staff at other medical centres.

  2. [Dosimetric system for assessing doses received by people occupationally exposed to external sources of ionizing radiation].

    Science.gov (United States)

    Brodecki, Marcin; Domienik, Joanna U; Zmyślony, Marek

    2012-01-01

    The current system of dosimetric quantities has been defined by the International Commission on Radiological Protection (ICRP) and the International Commission on Radiation Units and Measurements (ICRU). Complexity of the system implies the physical nature of ionizing radiation, resulting from the presence of different types of radiation of different ionization capabilities, as well as the individual radiation sensitivity of biological material exposed. According to the latest recommendations, there are three types of dosimeter quantities relevant to radiation protection and radiological assessment of occupational exposure. These are the basic quantities, safety quantities and operational quantities. Dose limits for occupational exposure relate directly to the protection quantities, i.e. the equivalent dose and effective dose, while these quantities are practically unmeasurable in real measurement conditions. For this reason, in the system of dosimetric quantities directly measurable operating volumes were defined. They represent equivalents of the protection quantities that allow for a reliable assessment of equivalent and effective dose by conducting routine monitoring of occupational exposure. This paper presents the characteristics of these quantities, their relationships and importance in assessing individual effects of radiation. Also the methods for their implementation in personal and environmental dosimetry were showcased. The material contained in the article is a compendium of essential information about dosimetric quantities with reference to the contemporary requirements of the law, including the changed annual occupational exposure limit for the lens of the eye. The material is especially addressed to those responsible for dosimetry monitoring in the workplace, radiation protection inspectors and occupational health physicians.

  3. Internal dose assessment due to large area contamination: Main lessons drawn from the Chernobyl accident

    Energy Technology Data Exchange (ETDEWEB)

    Andrasi, A. [KFKI Atomic Energy Research Inst., Budapest (Hungary)

    1997-03-01

    The reactor accident at Chernobyl in 1986 beside its serious and tragic consequences provided also an excellent opportunity to check, test and validate all kind of environmental models and calculation tools which were available in the emergency preparedness systems of different countries. Assessment of internal and external doses due to the accident has been carried out for the population all over Europe using different methods. Dose predictions based on environmental model calculation considering various pathways have been compared with those obtained by more direct monitoring methods. One study from Hungary and one from the TAEA is presented shortly. (orig./DG)

  4. Beyond dose assessment: using risk with full disclosure of uncertainty in public and scientific communication.

    Science.gov (United States)

    Hoffman, F Owen; Kocher, David C; Apostoaei, A Iulian

    2011-11-01

    Evaluations of radiation exposures of workers and the public traditionally focus on assessments of radiation dose, especially annual dose, without explicitly evaluating the health risk associated with those exposures, principally the risk of radiation-induced cancer. When dose is the endpoint of an assessment, opportunities to communicate the significance of exposures are limited to comparisons with dose criteria in regulations, doses due to natural background or medical x-rays, and doses above which a statistically significant increase of disease has been observed in epidemiologic studies. Risk assessment generally addresses the chance (probability) that specific diseases might be induced by past, present, or future exposure. The risk of cancer per unit dose will vary depending on gender, age, exposure type (acute or chronic), and radiation type. It is not uncommon to find that two individuals with the same effective dose will have substantially different risks. Risk assessment has shown, for example, that: (a) medical exposures to computed tomography scans have become a leading source of future risk to the general population, and that the risk would be increased above recently published estimates if the incidence of skin cancer and the increased risk from exposure to x-rays compared with high-energy photons were taken into account; (b) indoor radon is a significant contributor to the baseline risk of lung cancer, particularly among people who have never smoked; and (c) members of the public who were exposed in childhood to I in fallout from atmospheric nuclear weapons tests and were diagnosed with thyroid cancer later in life would frequently meet criteria established for federal compensation of cancers experienced by energy workers and military participants at atmospheric weapons tests. Risk estimation also enables comparisons of impacts of exposures to radiation and chemical carcinogens and other hazards to life and health. Communication of risk with

  5. Assessing Leg length Discrepancy Using a Biplane Low Dose Imaging System. A Comparative Diagnostic Study

    DEFF Research Database (Denmark)

    Jensen, Janni; Mussmann, Bo Redder; Torfing, Trine

    study was to evaluate the diagnostic accuracy of leg length (LL) measurements performed on low dose pre-view images acquired using a new bi-planar imaging system. The administered radiation dose from the pre-view image is approximately 20,17μGycm2 vs. 2670μGycm2 when acquiring the diagnostic image......Purpose. The etiology of leg length discrepancy (LLD) is multiple and children with LLD often undergo repetitive radiographic assessment and monitoring, stressing the need for a reliable measuring tool whilst administering as little radiation to the child as possible. The aim of this retrospective...

  6. Human Health Risk Assessment: A case study application of principles in dose response assessment

    Science.gov (United States)

    This case study application workshop will build on fundamental concepts and techniques in risk assessment presented and archived at previous TRAC meeting workshops. Practical examples from publicly available, peer reviewed risk assessments will be used as teaching aids. Course ...

  7. Dose assessment for ingestion of a 330 kilo-becquerel {sup 60}Co hot particle

    Energy Technology Data Exchange (ETDEWEB)

    Whillans, D.W.; Chase, W.J.; Wolodarsky, W.H. [Health Physics Department, Ontario Power Generation, Whitby, Ontario, L1 N 9E3 (Canada)

    2007-07-01

    On leaving the irradiated fuel bay at Pickering A nuclear power station, a worker triggered a whole body monitor alarm with activity in or on his head, and despite careful decontamination techniques he subsequently swallowed a hot particle. Over the next 3 d, the radioactivity was tracked through the body. It was then excreted in a single faecal sample and recovered for physical and radiochemical analysis. This analysis demonstrated that the particle contained 330 kBq of {sup 60}Co and only traces of other radioactivity. Its dimensions were {approx}50-130 {mu}m and its composition was consistent with that of Stellite 6. A dose assessment was carried out taking into account the residence time of the particle in the mouth and its transit through the body. The estimated committed effective dose was 1.4 mSv, and the equivalent dose to the maximally exposed 1 cm{sup 2} of skin, 81 mSv. (authors)

  8. Shutdown dose rate assessment with the Advanced D1S method: Development, applications and validation

    Energy Technology Data Exchange (ETDEWEB)

    Villari, R., E-mail: rosaria.villari@enea.it [Associazione EURATOM-ENEA sulla Fusione, Via Enrico Fermi 45, 00044 Frascati, Rome (Italy); Fischer, U. [Karlsruhe Institute of Technology KIT, Institute for Neutron Physics and Reactor Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Moro, F. [Associazione EURATOM-ENEA sulla Fusione, Via Enrico Fermi 45, 00044 Frascati, Rome (Italy); Pereslavtsev, P. [Karlsruhe Institute of Technology KIT, Institute for Neutron Physics and Reactor Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Petrizzi, L. [European Commission, DG Research and Innovation K5, CDMA 00/030, B-1049 Brussels (Belgium); Podda, S. [Associazione EURATOM-ENEA sulla Fusione, Via Enrico Fermi 45, 00044 Frascati, Rome (Italy); Serikov, A. [Karlsruhe Institute of Technology KIT, Institute for Neutron Physics and Reactor Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2014-10-15

    Highlights: Development of Advanced-D1S for shutdown dose rate calculations; Recent applications of the tool to tokamaks; Summary of the results of benchmarking with measurements and R2S calculations; Limitations and further development. Abstract: The present paper addresses the recent developments and applications of Advanced-D1S to the calculations of shutdown dose rate in tokamak devices. Results of benchmarking with measurements and Rigorous 2-Step (R2S) calculations are summarized and discussed as well as limitations and further developments. The outcomes confirm the essential role of the Advanced-D1S methodology and the evidence for its complementary use with the R2Smesh approach for the reliable assessment of shutdown dose rates and related statistical uncertainties in present and future fusion devices.

  9. Lack-of-fit tests for assessing mean structures for continuous dose-response data

    DEFF Research Database (Denmark)

    Martinussen, Torben

    2011-01-01

    We review a range of lack-of-fit tests suitable for assessing the appropriateness of the mean function in dose-response models. The review encompasses both well-known tests and new tests based on recent developments in statistics, which we have extended to the dose-response case. We argue...... that the classical methods are inadequate in certain situations, where the new tests may be applied. Power comparisons are carried out by means of extensive simulation studies, covering both designs with and without replicates at small and large sample sizes. Three datasets from dose-response applications illustrate...... differences and similarities between the tests. The results suggest that the new tests perform better and exhibit a wider applicability....

  10. A preliminary assessment of potential doses to man from radioactive waste dumped in the Arctic sea

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, S.P. [Risoe National Lab., Roskilde (Denmark); Iosjpe, M.; Strand, P. [Statens Straalevern, Oesteraas (Norway)

    1995-11-01

    This report describes a preliminary radiological assessment of collective doses to the world population from radioactive material dumped in the Kara and Barents Seas in the period 1961-1991. Information on the dumped waste and the rates of release of radionuclides have been available from Russian sources and from the International Atomic Energy Agency. A box model has been used to simulate the dispersion of radionuclides in the marine environment and to calculate the contamination of seafood and the subsequent radiation doses to man. Two release scenarios have been adopted. The worst-case release scenario, which ignores the presence of barriers between spent nuclear fuel and seawater, is estimated to give rise to about 10 mansievert calculated to 1000 years from the time of release. A more realistic release scenario is estimated to cause about 3 mansieverts. In both cases exposure from the radionuclide {sup 137}Cs is found to dominate the doses. 19 refs., 56 figs., 8 tabs.

  11. A preliminary assessment of potential doses to man from radioactive waste dumped in the Arctic Sea

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, S.P. [Forskningscente Risoe, Roskilde (Denmark); Iosjpe, M.; Strand, P. [Norwegian Radiation Protection Authority, Oesteraas (Norway)

    1995-09-01

    This report describes a preliminary radiological assessment of collective doses to the world population from radioactive material dumped in the Barents and Kara Seas in the period 1961-1991. Information on the dumped waste and the rates of release of radionuclides have been available from Russian sources and from the International Atomic Energy Agency. A box model has been used to simulate the dispersion of radionuclides in the marine environment and to calculate the contamination of seafood and the subsequent radiation doses to man. Two release scenarios have been adopted. The worst-case release scenario which ignores the presence of barriers between spent nuclear fuel and seawater is estimated to give rise to about 10 mansieverts calculated to 1000 years from the time of release. A more realistic release scenario is estimated to cause about 3 mansieverts. In both cases exposure from the radionuclide {sup 137}Cs is found to dominate the doses. (au) 8 tabs., 56 ills., 19 refs.

  12. Inferring 3D kinematics of carpal bones from single view fluoroscopic sequences.

    Science.gov (United States)

    Chen, Xin; Graham, Jim; Hutchinson, Charles; Muir, Lindsay

    2011-01-01

    We present a novel framework for inferring 3D carpal bone kinematics and bone shapes from a single view fluoroscopic sequence. A hybrid statistical model representing both the kinematics and shape variation of the carpal bones is built, based on a number of 3D CT data sets obtained from different subjects at different poses. Given a fluoroscopic sequence, the wrist pose, carpal bone kinematics and bone shapes are estimated iteratively by matching the statistical model with the 2D images. A specially designed cost function enables smoothed parameter estimation across frames. We have evaluated the proposed method on both simulated data and real fluoroscopic sequences. It was found that the relative positions between carpal bones can be accurately estimated, which is potentially useful for detection of conditions such as scapholunate dissociation.

  13. Thyroid, parathyroid, and salivary gland evaluations in patients exposed to multiple fluoroscopic examinations during tuberculosis therapy: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, M.M.; Boice, J.D. Jr.; Ames, D.B.; Rosenstein, M.

    1988-02-01

    The prevalence of thyroid, parathyroid, and salivary abnormalities was determined in 91 women who received an average of 112 fluoroscopic chest examinations during pneumothorax treatment for tuberculosis more than 40 yr previously and in 72 women treated for tuberculosis by other modalities. Thyroid abnormalities were determined by physical examination, scintiscans, and measurements of serum free T4 index, TSH, and thyroid microsomal antibodies. Thyroid nodules were diagnosed in 7.7% of the exposed and 4.2% of the comparison group (prevalence ratio, 1.8; 90% confidence interval 0.6-5.7). Autoimmune thyroid disease was diagnosed in 15.2% of the exposed and 6.9% of the comparison group (prevalence ratio, 2.2; 95% confidence interval, 0.8-6.2). No salivary tumors were detected. Two exposed women and 1 comparison woman had primary hyperparathyroidism. Although absorbed dose to the thyroid could not be precisely determined, approximately 60 rads would be expected to yield the observed excess of thyroid nodules. While the prevalence ratios were not significantly increased in the exposed group, the results suggest that susceptibility of the thyroid to nodules from cumulative radiation doses of this magnitude could be increased even when the doses are accumulated over years and that such x-ray exposure of the thyroid gland may predispose the patient to the development of autoimmune disease.

  14. Radiation therapy for stage IIA and IIB testicular seminoma: peripheral dose calculations and risk assessments

    Science.gov (United States)

    Mazonakis, Michalis; Berris, Theocharris; Lyraraki, Efrossyni; Damilakis, John

    2015-03-01

    This study was conducted to calculate the peripheral dose to critical structures and assess the radiation risks from modern radiotherapy for stage IIA/IIB testicular seminoma. A Monte Carlo code was used for treatment simulation on a computational phantom representing an average adult. The initial treatment phase involved anteroposterior and posteroanaterior modified dog-leg fields exposing para-aortic and ipsilateral iliac lymph nodes followed by a cone-down phase for nodal mass irradiation. Peripheral doses were calculated using different modified dog-leg field dimensions and an extended conventional dog-leg portal. The risk models of the BEIR-VII report and ICRP-103 were combined with dosimetric calculations to estimate the probability of developing stochastic effects. Radiotherapy for stage IIA seminoma with a target dose of 30 Gy resulted in a range of 23.0-603.7 mGy to non-targeted peripheral tissues and organs. The corresponding range for treatment of stage IIB disease to a cumulative dose of 36 Gy was 24.2-633.9 mGy. A dose variation of less than 13% was found by altering the field dimensions. Radiotherapy with the conventional instead of the modern modified dog-leg field increased the peripheral dose up to 8.2 times. The calculated heart doses of 589.0-632.9 mGy may increase the risk for developing cardiovascular diseases whereas the testicular dose of more than 231.9 mGy may lead to a temporary infertility. The probability of birth abnormalities in the offspring of cancer survivors was below 0.13% which is much lower than the spontaneous mutation rate. Abdominoplevic irradiation may increase the lifetime intrinsic risk for the induction of secondary malignancies by 0.6-3.9% depending upon the site of interest, patient’s age and tumor dose. Radiotherapy for stage IIA/IIB seminoma with restricted fields and low doses is associated with an increased morbidity. These data may allow the definition of a risk-adapted follow-up scheme for long

  15. Actual versus prescribed timing of lovastatin doses assessed by electronic compliance monitoring.

    Science.gov (United States)

    Kruse, W; Nikolaus, T; Rampmaier, J; Weber, E; Schlierf, G

    1993-01-01

    The objective of the study was to compare compliance with and the hypocholesterolaemic effect of lovastatin given once daily as a morning or an evening dose. Twenty-four out-patients with familial hypercholesterolaemia were randomly assigned to receive placebo first, then lovastatin 20 mg, to be taken once daily for 4 weeks, either with the breakfast or evening meal, in a single-blind fashion. Drug compliance was assessed by pill counts and continuous electronic monitoring. Two compliance parameters were evaluated, consumption, defined as percentage of prescribed doses taken, and time compliance, the percentage of total dosing events recorded within defined intervals (6.00-10.00 h, and 17.00-21.00 h), for the morning and evening regimes. Both regimes satisfactorily reduced the total and LDL-cholesterol concentrations, and there was no significant difference in the extent of the reductions. Pill counts overestimated compliance, as revealed by the monitoring method. The times of actual consumption of doses by the patients often differed from that prescribed, predominantly in patients who were told to take the evening dose. Partial time compliance may have confounded the efficacy of the drugs. Electronic compliance monitoring appears to be particularly useful in chronopharmacological studies.

  16. Internal dose assessment data management system for a large population of Pu workers

    Energy Technology Data Exchange (ETDEWEB)

    Bertelli, L.; Miller, G.; Little, T.; Guilmette, R.A. [Los Alamos National Laboratory, MS G761, RP-2, Los Alamos, NM 87545 (United States); Glasser, S.M. [LogiCreativity, Santa Fe, NM (United States)

    2007-07-01

    This paper describes the design and implementation of the Los Alamos National Laboratory (LANL) dose assessment (DA) data system. Dose calculations for the most important radionuclides at LANL, namely plutonium, americium, uranium and tritium, are performed through the Microsoft Access DA database. DA includes specially developed forms and macros that perform a variety of tasks, such as retrieving bioassay data, launching the FORTRAN internal dosimetry applications and displaying dose results in the form of text summaries and plots. The DA software involves the following major processes: (1) downloading of bioassay data from a remote data source, (2) editing local and remote databases, (3) setting up and carrying out internal dose calculations using the UF code or the ID code, (3) importing results of the dose calculations into local results databases, (4) producing a secondary database of 'official results' and (5) automatically creating and e-mailing reports. The software also provides summary status and reports of the pending DAs, which are useful for managing the cases in process. (authors)

  17. Realistic retrospective dose assessments to members of the public around Spanish nuclear facilities.

    Science.gov (United States)

    Jiménez, M A; Martín-Valdepeñas, J M; García-Talavera, M; Martín-Matarranz, J L; Salas, M R; Serrano, J I; Ramos, L M

    2011-11-01

    In the frame of an epidemiological study carried out in the influence areas around the Spanish nuclear facilities (ISCIII-CSN, 2009. Epidemiological Study of The Possible Effect of Ionizing Radiations Deriving from The Operation of Spanish Nuclear Fuel Cycle Facilities on The Health of The Population Living in Their Vicinity. Final report December 2009. Ministerio de Ciencia e Innovación, Instituto de Salud Carlos III, Consejo de Seguridad Nuclear. Madrid. Available from: http://www.csn.es/images/stories/actualidad_datos/especiales/epidemiologico/epidemiological_study.pdf), annual effective doses to public have been assessed by the Spanish Nuclear Safety Council (CSN) for over 45 years using a retrospective realistic-dose methodology. These values are compared with data from natural radiation exposure. For the affected population, natural radiation effective doses are in average 2300 times higher than effective doses due to the operation of nuclear installations (nuclear power stations and fuel cycle facilities). When considering the impact on the whole Spanish population, effective doses attributable to nuclear facilities represent in average 3.5×10(-5)mSv/y, in contrast to 1.6mSv/y from natural radiation or 1.3mSv/y from medical exposures.

  18. Benchmark dose profiles for joint-action quantal data in quantitative risk assessment.

    Science.gov (United States)

    Deutsch, Roland C; Piegorsch, Walter W

    2012-12-01

    Benchmark analysis is a widely used tool in public health risk analysis. Therein, estimation of minimum exposure levels, called Benchmark Doses (BMDs), that induce a prespecified Benchmark Response (BMR) is well understood for the case of an adverse response to a single stimulus. For cases where two agents are studied in tandem, however, the benchmark approach is far less developed. This article demonstrates how the benchmark modeling paradigm can be expanded from the single-dose setting to joint-action, two-agent studies. Focus is on response outcomes expressed as proportions. Extending the single-exposure setting, representations of risk are based on a joint-action dose-response model involving both agents. Based on such a model, the concept of a benchmark profile (BMP) - a two-dimensional analog of the single-dose BMD at which both agents achieve the specified BMR - is defined for use in quantitative risk characterization and assessment. The resulting, joint, low-dose guidelines can improve public health planning and risk regulation when dealing with low-level exposures to combinations of hazardous agents.

  19. Biosphere Modeling for the Dose Assessment of a HLW Repository: Development of ACBIO

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Youn Myoung; Hwang, Yong Soo; Kang, Chul Hyung

    2006-01-15

    For the purpose of evaluating a dose rate to an individual due to a long-term release of nuclides from a HLW repository, a biosphere assessment model and an implemented code, ACBIO, based on the BIOMASS methodology have been developed by utilizing AMBER, a general compartment modeling tool. To demonstrate its practicability and usability as well as to observe the sensitivity of the compartment scheme, the concentration, the activity in the compartments as well as the annual flux between the compartments at their peak values, were calculated and investigated. For each case when changing the structure of the compartments and GBIs as well as varying selected input Kd values, all of which seem very important among the others, the dose rate per nuclide release rate is calculated separately and analyzed. From the maximum dose rates, the flux to dose conversion factors for each nuclide were derived, which are used for converting the nuclide release rate appearing from the geosphere through various GBIs to dose rates (Sv/y) for an individual in a critical group. It has also been observed that the compartment scheme, the identification of a possible exposure group and the GBIs could all be highly sensitive to the final consequences in a biosphere modeling.

  20. Assessment of CpTi Surface Properties after Nitrogen Ion Implantation with Various Doses and Energies

    Science.gov (United States)

    Fulazzaky, Mohamad Ali; Ali, Nurdin; Samekto, Haryanti; Ghazali, Mohd Imran

    2012-11-01

    Nitrogen ion implantation is one of the surface modification techniques used for increasing corrosion resistance of commercially pure titanium (CpTi). The nitrogen ion implanted CpTi in various doses markedly changes the corrosion resistance. Still the effect of nitrogen ion implantation on the CpTi at different energies needs to be verified. This study uses different methods to assess the CpTi surface properties after nitrogen ion implantation in various doses and energy. Surface hardness of the CpTi increases with an increase of the dose and decreases with an increase of the energy. The precipitation of the TiN increases with an increase of the nitrogen dose, and no formation of the Ti2N phase clearly appears. Corrosion resistance of the CpTi specimens can be upgraded to some extent after their surfaces are modified, implanting nitrogen ions at 100 keV by increasing dose. The optimum surface properties of the implanted CpTi are analyzed to contribute to materials science technology.

  1. Hazard identification and characterisation, and dose response assessment of spore forming pathogens in cooked chilled food containing vegetables

    NARCIS (Netherlands)

    Leusden FM van; MGB

    2001-01-01

    A hazard identification and characterisation, including a preliminary dose response assessment, of sporeforming pathogens in cooked chilled food containing vegetables was performed according to the structure and principles for a quantitative microbiological risk assessment as described by the Codex

  2. Multiple Methods for Assessing the Dose to Skin Exposed to Radioactive Contamination.

    Science.gov (United States)

    Dubeau, J; Heinmiller, B E; Corrigan, M

    2017-04-28

    There is the possibility for a worker at a nuclear installation, such as a nuclear power reactor, a fuel production facility or a medical facility, to come in contact with radioactive contaminants. When such an event occurs, the first order of business is to care for the worker by promptly initiating a decontamination process. Usually, the radiation protection personnel performs a G-M pancake probe measurement of the contamination in situ and collects part or all of the radioactive contamination for further laboratory analysis. The health physicist on duty must then perform, using the available information, a skin dose assessment that will go into the worker's permanent dose record. The contamination situations are often complex and the dose assessment can be laborious. This article compares five dose assessment methods that involve analysis, new technologies and new software. The five methods are applied to 13 actual contamination incidents consisting of direct skin contact, contamination on clothing and contamination on clothing in the presence of an air gap between the clothing and the skin. This work shows that, for the cases studied, the methods provided dose estimates that were usually within 12% (1σ) of each other, for those cases where absolute activity information for every radionuclide was available. One method, which relies simply on a G-M pancake probe measurement, appeared to be particularly useful in situations where a contamination sample could not be recovered for laboratory analysis. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Cancer risk assessment: Optimizing human health through linear dose-response models.

    Science.gov (United States)

    Calabrese, Edward J; Shamoun, Dima Yazji; Hanekamp, Jaap C

    2015-07-01

    This paper proposes that generic cancer risk assessments be based on the integration of the Linear Non-Threshold (LNT) and hormetic dose-responses since optimal hormetic beneficial responses are estimated to occur at the dose associated with a 10(-4) risk level based on the use of a LNT model as applied to animal cancer studies. The adoption of the 10(-4) risk estimate provides a theoretical and practical integration of two competing risk assessment models whose predictions cannot be validated in human population studies or with standard chronic animal bioassay data. This model-integration reveals both substantial protection of the population from cancer effects (i.e. functional utility of the LNT model) while offering the possibility of significant reductions in cancer incidence should the hormetic dose-response model predictions be correct. The dose yielding the 10(-4) cancer risk therefore yields the optimized toxicologically based "regulatory sweet spot". Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Spinal cord injury from fluoroscopically guided intercostal blocks with phenol.

    Science.gov (United States)

    Kissoon, Narayan R; Graff-Radford, Jonathan; Watson, James C; Laughin, Ruple S

    2014-01-01

    Image guided intercostal blocks are commonly performed and considered relatively safe. Chemical denervation is commonly used in clinical practice for treatment of chronic non-cancer associated pain. To report a case of spinal cord injury resulting from fluoroscopically guided intercostal blocks with phenol. Case report. Inpatient hospital service. RESULTS/CASE REPORTS: A 53 year-old women was transferred from her local facility for acute onset of lower extremity paresis beginning shortly after right intercostal nerve injections of 2 mL of preservative-free phenol at the T7, 8, 9 levels. She had previous intercostal blocks for chronic right-sided mid thoracic/abdominal pain every 3 months for at least one year without sequelae. Within 20 minutes of the injection, she developed a sensation of right leg weakness and heaviness. Over several hours she developed worsening right leg weakness, and then left leg weakness, followed by urinary retention. Admission examination revealed severe right greater than left leg weakness, right lower extremity hyperesthesia to T10, absent lower extremity reflexes, and bilateral extensor plantar responses. Magnetic resonance imaging (MRI) of the entire spine demonstrated extensive T2/DWI hyperintensity in the central spinal cord from T1 to L1 with mild cord enlargement and enhancement at T7-9 (sites of injection). Extensive serum and cerebrospinal fluid (CSF) evaluation did not show any evidence of an infectious, inflammatory, or metabolic cause to her myelopathy. Repeat MRI of the entire spine demonstrated near complete resolution of the T2 signal abnormality. One month after presentation, despite radiographic improvement, the patient showed some clinical improvement, but remained walker dependent and with neurogenic bowel and bladder. This report describes a single case report. This case offers several lessons for a pain specialist including 1) the potential for a neurologic catastrophe (spinal cord injury) from aqueous neurolytic

  5. Dose assessment for inhalation intakes in complex, energetic environments: experience from the US Capstone study.

    Science.gov (United States)

    Guilmette, Raymond A; Parkhurst, Mary Ann

    2007-01-01

    Because of the lack of existing information needed to evaluate the risks from inhalation exposures to depleted uranium (DU) aerosols of US soldiers during the 1991 Persian Gulf War, the US Department of Defense funded an experimental study to measure the characteristics of DU aerosols created when Abrams tanks and Bradley fighting vehicles are struck with large-caliber DU penetrators, and a dose and risk assessment for individuals present in such vehicles. This paper describes some of the difficulties experienced in dose assessment modelling of the very complex DU aerosols created in the Capstone studies, e.g. high concentrations, heterogeneous aerosol properties, non-lognormal particle size distributions, triphasic in vitro dissolution and rapid time-varying functions of both DU air concentration and particle size. The approaches used to solve these problems along with example results are presented.

  6. RADCOM: a computerized translation device for use during fluoroscopic examination of non-English-speaking patients.

    Science.gov (United States)

    Cohn, M J; Cohen, A J

    1994-02-01

    We developed and have implemented RADCOM (RADiology COMmunicator), a computerized speech-based language translator for use during fluoroscopic examination of non-English-speaking patients. It is controlled completely by voice commands issued into a headset microphone. The system output is digital audio via a small speaker, in the native language of the patient. RADCOM currently supports more than 40 commands in more than a dozen languages. The language data base is easily expandable. We have performed more than 20 fluoroscopic examinations with the RADCOM system. The non-English-speaking patients respond well, following the selected instructions appropriately.

  7. Technique for Percutaneous Fluoroscopically Guided G-Tube Placement in a High-BMI Patient

    Directory of Open Access Journals (Sweden)

    Irwin M. Best

    2012-01-01

    Full Text Available Enteral feeding is still the preferred method of nutritional support even in patients with excessive body mass index. Often, this mass poses a hindrance in performing routine procedures. We present a case describing the technique used to safely place a fluoroscopically guided G-tube in a patient with a significant nutritional deficit after repair of a ruptured thoracic aneurysm. Her admission weight was in excess of 180 Kg. However, protracted respiratory insufficiency and mechanical ventilation prolonged her hospital course. The G-tube was successfully placed using a fluoroscopically guided technique. The advantages of such an approach are discussed.

  8. Technique for Percutaneous Fluoroscopically Guided G-Tube Placement in a High-BMI Patient.

    Science.gov (United States)

    Best, Irwin M

    2012-01-01

    Enteral feeding is still the preferred method of nutritional support even in patients with excessive body mass index. Often, this mass poses a hindrance in performing routine procedures. We present a case describing the technique used to safely place a fluoroscopically guided G-tube in a patient with a significant nutritional deficit after repair of a ruptured thoracic aneurysm. Her admission weight was in excess of 180 Kg. However, protracted respiratory insufficiency and mechanical ventilation prolonged her hospital course. The G-tube was successfully placed using a fluoroscopically guided technique. The advantages of such an approach are discussed.

  9. Assessment of The Dose-Response Relationship of Radiation-Induced Bystander Effect in Two Cell Lines Exposed to High Doses of Ionizing Radiation (6 and 8 Gy).

    Science.gov (United States)

    Bahreyni Toossi, Mohammad Taghi; Khademi, Sara; Azimian, Hosein; Mohebbi, Shokoufeh; Soleymanifard, Shokouhozaman

    2017-10-01

    The dose-response relationship of radiation-induced bystander effect (RIBE) is controversial at high dose levels. The aim of the present study is to assess RIBE at high dose levels by examination of different endpoints. This experimental study used the medium transfer technique to induce RIBE. The cells were divided into two main groups: QU-DB cells which received medium from autologous irradiated cells and MRC5 cells which received medium from irradiated QU-DB cells. Colony, MTT, and micronucleus assays were performed to quantify bystander responses. The medium was diluted and transferred to bystander cells to investigate whether medium dilution could revive the RIBE response that disappeared at a high dose. The RIBE level in QU-DB bystander cells increased in the dose range of 0.5 to 4 Gy, but decreased at 6 and 8 Gy. The Micronucleated cells per 1000 binucleated cells (MNBN) frequency of QU-DB bystander cells which received the most diluted medium from 6 and 8 Gy QU-DB irradiated cells reached the maximum level compared to the MNBN frequency of the cells that received complete medium (Pbystander cells. This finding confirmed that a negative feedback mechanism was responsible for the decrease in RIBE response at high doses. Decrease of RIBE at high doses might be used to predict that in radiosurgery, brachytherapy and grid therapy, in which high dose per fraction is applied, normal tissue damage owing to RIBE may decrease.

  10. Skin Dose Assessment Methodology for Military Personnel at McMurdo Station, Antarctica (1962-1979)

    Science.gov (United States)

    2014-06-01

    Regulatory Commission, Rockville, MD. May 20. WHO (World Health Organization), 2005. Health Effects of the Chernobyl Accident and Special Health Care...Programmes, Report of the UN Chernobyl Forum Expert Group “ Health ” (EGH), World Health Organization, Geneva. August 31. 18 This page intentionally...McMurdo Station Radiation Dose Assessment Integrated Project Team For: Assistant Secretary of Defense for Health Affairs and Deputy Assistant

  11. Fluoroscopic Analysis of Tibial Translation in Anterior Cruciate Ligament Injured Knees With and Without Bracing During Forward Lunge

    Directory of Open Access Journals (Sweden)

    Jalali

    2015-07-01

    Full Text Available Background Despite several studies with different methods, the effect of functional knee braces on knee joint kinematics is not clear. Direct visualization of joint components through medical imaging modalities may provide the clinicians with more useful information. Objectives In this study, for the first time in the literature, video fluoroscopy was used to investigate the effect of knee bracing on the sagittal plane kinematics of anterior cruciate ligament (ACL injured patients. Patients and Methods For twelve male unilateral ACL deficient subjects, the anterior tibial translation was measured during lunge exercise in non-braced and braced conditions. Fluoroscopic images were acquired from the subjects using a digital fluoroscopy system with a rate of 10 fps. The image of each frame was scaled using a calibration coin and analyzed in AutoCAD environment. The angle between the two lines, tangent to the posterior cortexes of the femoral and tibial shafts was measured as the flexion angle. For the fluoroscopic images associated with 0°, 15°, 30°, 45° and 60° knee flexion angles, the relative anterior-posterior configuration of the tibiofemoral joint was assessed by measuring the position of landmarks on the tibia and femur. Results Results indicated that the overall anterior translations of the tibia during the eccentric (down and concentric (up phases of lunge exercise were 10.4 ± 1.7 mm and 9.0 ± 2.2 mm for non-braced, and 10.1 ± 3.4 mm and 7.4 ± 2.5 mm, for braced conditions, respectively. The difference of the tibial anterior-posterior translation behaviors of the braced and non-braced knees was not statistically significant. Conclusion Fluoroscopic imaging provides an effective tool to measure the dynamic behavior of the knee joint in the sagittal plane and within the limitations of this study, the pure mechanical stabilizing effect of functional knee bracing is not sufficient to control the anterior tibial translation of the ACL

  12. Pilot website to support international collaboration for dose assessments in a radiation emergency

    Energy Technology Data Exchange (ETDEWEB)

    Livingston, G.K., E-mail: Gordon.Livingston@orise.orau.gov [Oak Ridge Associated Universities, REAC/TS, Radiation Emergency Medicine (REM), P.O. Box 117, Oak Ridge, TN 37831 (United States); Wilkins, R.C., E-mail: Ruth.Wilkins@hc-sc.gc.ca [Health Canada, Consumer and Clinical Radiation Protection Bureau, Ottawa, ON K1A 1C1 (Canada); Ainsbury, E.A., E-mail: liz.ainsbury@hpa.org.uk [Health Protection Agency, Radiation Protection Division, Chilton, Didcot, Oxfordshire OX11 0RQ (United Kingdom)

    2011-09-15

    Nuclear terrorism has emerged as a significant threat which could require timely medical interventions to reduce potential radiation casualties. Early dose assessments are critical since optimal care depends on knowing a victim's radiation dose. The dicentric chromosome aberration assay is considered the 'gold standard' to estimate the radiation dose because the yield of dicentrics correlates positively with the absorbed dose. Dicentrics have a low background frequency, are independent of age and gender and are relatively easy to identify. This diagnostic test for radiation exposure, however, is labor intensive and any single or small group of laboratories could easily be overwhelmed by a mass casualty event. One solution to this potential problem is to link the global WHO BioDoseNet members via the Internet so multiple laboratories could work cooperatively to screen specimens for dicentric chromosomes and generate timely dose estimates. Inter-laboratory comparison studies have shown that analysis of electronic chromosome images viewed on the computer monitor produces scoring accuracy equivalent to viewing live images in the microscope. This functional equivalence was demonstrated during a comparative study involving five laboratories constructing {sup 60}Co gamma ray calibration curves and was further confirmed when comparing results of blind dose estimates submitted by each laboratory. It has been further validated in two recent WHO BioDoseNet trial exercises where 20 metaphase images were shared by e-mail and 50 images were shared on a test website created for this purpose. The Internet-based exercise demonstrated a high level of concordance among 20 expert scorers who evaluated the same 50 metaphase spreads selected to exhibit no, low, moderate and severe radiation damage. Nineteen of 20 scorers produced dicentric equivalent counts within the 95% confidence limits of the mean. The Chi-squared test showed strong evidence of homogeneity in the data

  13. Dose assessment in environmental radiological protection: State of the art and perspectives.

    Science.gov (United States)

    Stark, Karolina; Goméz-Ros, José M; Vives I Batlle, Jordi; Lindbo Hansen, Elisabeth; Beaugelin-Seiller, Karine; Kapustka, Lawrence A; Wood, Michael D; Bradshaw, Clare; Real, Almudena; McGuire, Corynne; Hinton, Thomas G

    2017-09-01

    Exposure to radiation is a potential hazard to humans and the environment. The Fukushima accident reminded the world of the importance of a reliable risk management system that incorporates the dose received from radiation exposures. The dose to humans from exposure to radiation can be quantified using a well-defined system; its environmental equivalent, however, is still in a developmental state. Additionally, the results of several papers published over the last decade have been criticized because of poor dosimetry. Therefore, a workshop on environmental dosimetry was organized by the STAR (Strategy for Allied Radioecology) Network of Excellence to review the state of the art in environmental dosimetry and prioritize areas of methodological and guidance development. Herein, we report the key findings from that international workshop, summarise parameters that affect the dose animals and plants receive when exposed to radiation, and identify further research needs. Current dosimetry practices for determining environmental protection are based on simple screening dose assessments using knowledge of fundamental radiation physics, source-target geometry relationships, the influence of organism shape and size, and knowledge of how radionuclide distributions in the body and in the soil profile alter dose. In screening model calculations that estimate whole-body dose to biota the shapes of organisms are simply represented as ellipsoids, while recently developed complex voxel phantom models allow organ-specific dose estimates. We identified several research and guidance development priorities for dosimetry. For external exposures, the uncertainty in dose estimates due to spatially heterogeneous distributions of radionuclide contamination is currently being evaluated. Guidance is needed on the level of dosimetry that is required when screening benchmarks are exceeded and how to report exposure in dose-effect studies, including quantification of uncertainties. Further

  14. An assessment of bias and uncertainty in recorded dose from external sources of radiation for workers at the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Fix, J.J.; Gilbert, E.S.; Baumgartner, W.V.

    1994-08-01

    Worker dose estimates are used in epidemiologic studies of nuclear workers. A major objective of these studies is to provide a direct assessment of the carcinogenic risk of exposure to ionizing radiation at low doses and dose rates. If dose estimates used in analyses of worker data are biased, then risk estimates expressed per unit of dose will also be biased. In addition, random error in dose estimates may lead to underestimation of risk coefficients and can also distort dose-response analyses. Analyses of data from nuclear worker studies, including Hanford, have typically not been adjusted for biases and uncertainties in dose estimates in part because of the lack of adequate information on the nature and magnitude of these biases and uncertainties. This report describes an approach used to assess bias and uncertainty in radiation dose for Hanford dosimetry systems. The approach can be considered as an elaboration of work conducted by a technical committee appointed by the National Academy of Sciences (NAS) used to quantify the bias and uncertainty in estimated doses for personnel exposed to radiation as a result of atmospheric testing of nuclear weapons between 1945 and 1962. In addition, laboratory studies were conducted to measure bias for selected sources of photon radiation resulting from angular response characteristics of Hanford dosimeter systems. An overall assessment is presented of bias and uncertainty for photon radiation greater than 100 keV. This radiation is expected to have caused the vast majority of recorded dose for Hanford workers.

  15. A small-signal approach to temporal modulation transfer functions with exposure-rate dependence and its application to fluoroscopic detective quantum efficiency.

    Science.gov (United States)

    Friedman, S N; Cunningham, I A

    2009-08-01

    The detective quantum efficiency (DQE) is a metric widely used in radiography to quantify system performance and as a surrogate measure of patient "dose efficiency." It has been applied previously to fluoroscopic systems with the introduction of a temporal correction factor. Calculation of this correction factor relies on measurements of the temporal modulation transfer function (MTF). However, the temporal MTF is often exposure-rate dependent, violating a necessary Fourier linearity requirement. The authors show that a Fourier analysis is appropriate for fluoroscopic systems if a "small-signal" approach is used. Using a semitransparent edge, a lag-corrected DQE is described and measured for an x-ray image intensifier-based fluoroscopic system under continuous (non-pulsed) exposure conditions. It was found that results were equivalent for both rising and falling-edge profiles independent of edge attenuation when effective attenuation was in the range of 0.1-0.6. This suggests that this range is appropriate for measuring the small-signal temporal MTF. In general, lag was greatest at low exposure rates. It was also found that results obtained using a falling-edge profile with a radiopaque edge were equivalent to the small-signal results for the test system. If this result is found to be true generally, it removes the need for the small-signal approach. Lag-corrected DQE values were validated by comparison with radiographic DQE values obtained using very long exposures under the same conditions. Lag was observed to inflate DQE measurements by up to 50% when ignored.

  16. Probabilistic assessment of the influence of lake properties in long-term radiation doses to humans.

    Science.gov (United States)

    Pohjola, Jari; Turunen, Jari; Lipping, Tarmo; Ikonen, Ari T K

    2016-11-01

    The assessment processes concerning the safety of nuclear waste repositories include the modelling of radionuclide transport in biosphere and the evaluation of the doses to the most affected humans. In this paper, a scenario, in which a contaminated lake is the water source for drinking water, irrigation water and watering of livestock, is presented. The objective of the paper is to probabilistically study the influence of lake properties as parameters in the assessment scenario. The properties of the lake are a result of previously conducted probabilistic studies, where the land uplift of the terrain surrounding the repositories and the formation of water bodies were studied in a 10,000-year time span using Monte Carlo simulation. The lake is formed at 3000 years from present day and the changing properties of the lake have been used in the study. The studied radionuclides (36)Cl, (135)Cs, (129)I, (237)Np, (90)Sr, (99)Tc and (238)U enter the lake with a rate of 1 Bq/year. The transport process from the lake water to humans is described and the doses (dose conversion factors) to adult humans are evaluated based on a study on average food consumption. Sensitivity analysis is used for identifying the parameters having the most influence on the outcome of the dose. Based on the results from the sensitivity analysis, the volumetric outflow rate of the lake and the volume of the lake were taken into closer consideration. The results show the influence of probabilistically derived geomorphic lake input parameters on the dose. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. A novel approach to pharmacodynamic assessment of antimicrobial agents: new insights to dosing regimen design.

    Directory of Open Access Journals (Sweden)

    Vincent H Tam

    Full Text Available Pharmacodynamic modeling has been increasingly used as a decision support tool to guide dosing regimen selection, both in the drug development and clinical settings. Killing by antimicrobial agents has been traditionally classified categorically as concentration-dependent (which would favor less fractionating regimens or time-dependent (for which more frequent dosing is preferred. While intuitive and useful to explain empiric data, a more informative approach is necessary to provide a robust assessment of pharmacodynamic profiles in situations other than the extremes of the spectrum (e.g., agents which exhibit partial concentration-dependent killing. A quantitative approach to describe the interaction of an antimicrobial agent and a pathogen is proposed to fill this unmet need. A hypothetic antimicrobial agent with linear pharmacokinetics is used for illustrative purposes. A non-linear functional form (sigmoid Emax of killing consisted of 3 parameters is used. Using different parameter values in conjunction with the relative growth rate of the pathogen and antimicrobial agent concentration ranges, various conventional pharmacodynamic surrogate indices (e.g., AUC/MIC, Cmax/MIC, %T>MIC could be satisfactorily linked to outcomes. In addition, the dosing intensity represented by the average kill rate of a dosing regimen can be derived, which could be used for quantitative comparison. The relevance of our approach is further supported by experimental data from our previous investigations using a variety of gram-negative bacteria and antimicrobial agents (moxifloxacin, levofloxacin, gentamicin, amikacin and meropenem. The pharmacodynamic profiles of a wide range of antimicrobial agents can be assessed by a more flexible computational tool to support dosing selection.

  18. Patients exposure from fluoroscopic guided pacemaker implantation procedures

    Energy Technology Data Exchange (ETDEWEB)

    Alkhorayef, M.; Babikir, E. [King Saud University, College of Applied Sciences, Radiological Sciences Department, P. O. Box 10219, Riyadh 11433 (Saudi Arabia); Sulieman, A. [Prince Sattam bin Abdulaziz University, College of Applied Medical Sciences, Radiology and Medical Imaging Department, P. O. Box 422, Alkharj 11942 (Saudi Arabia); Daar, E. [University of Jordan, Faculty of Science, Department of Physics, Amman 11942 (Jordan); Alnaaimi, M.; Alduaij, M. [Kuwait Cancer Control Centre, Department of Nuclear Medicine, Shwiekh (Kuwait); Bradley, D., E-mail: malkhorayef@ksu.edu.sa [University of Surrey, Centre for Nuclear and Radiation Physics, Guildford, Surrey, GU2 7XH (United Kingdom)

    2016-10-15

    A pacemaker, which is used for heart re synchronization with electrical impulses, is used to manage many clinical conditions. Recently, the frequency of the pacemaker implantation procedures increased 50% worldwide. During this procedure, patients and staff can be exposed to excessive radiation exposure. Wide range of doses was reported in previous studies, suggesting that optimization of this procedure is not fulfilled yet. This study aims to evaluate the patient and staff radiation doses during cardiac pacemaker procedure and quantify the patient effective dose. A total of 145 procedures were performed for five pacemakers procedures (VVI, VVIR, VVD, VVDR and DDDR) two hospitals were evaluated. Patients doses were measured using the kerma-area product meter. Effective doses were estimated using software based on Monte Carlo simulation from National Radiological Protection Board. The effective dose values were used to estimate the cancer risk from pacemaker procedure. Patients demographic data, exposure parameters for both fluoroscopy and radiography were quantified. The mean patients doses (Gy. cm{sup 2}) for VVI, VVIR, VVD, VVDR and DDDR was 1.52±0.13 (1.43-1.61), 3.28±2.34 (0.29-8.73), 3.04±1.67 (1.57-4.86), 6.04±2.326 and 19.2±3.6 (5.43-30.2), respectively, per procedure. The overall patients effective dose is 1.1 mSv per procedure. (Author)

  19. Standardizing Benchmark Dose Calculations to Improve Science-Based Decisions in Human Health Assessments

    Science.gov (United States)

    Wignall, Jessica A.; Shapiro, Andrew J.; Wright, Fred A.; Woodruff, Tracey J.; Chiu, Weihsueh A.; Guyton, Kathryn Z.

    2014-01-01

    Background: Benchmark dose (BMD) modeling computes the dose associated with a prespecified response level. While offering advantages over traditional points of departure (PODs), such as no-observed-adverse-effect-levels (NOAELs), BMD methods have lacked consistency and transparency in application, interpretation, and reporting in human health assessments of chemicals. Objectives: We aimed to apply a standardized process for conducting BMD modeling to reduce inconsistencies in model fitting and selection. Methods: We evaluated 880 dose–response data sets for 352 environmental chemicals with existing human health assessments. We calculated benchmark doses and their lower limits [10% extra risk, or change in the mean equal to 1 SD (BMD/L10/1SD)] for each chemical in a standardized way with prespecified criteria for model fit acceptance. We identified study design features associated with acceptable model fits. Results: We derived values for 255 (72%) of the chemicals. Batch-calculated BMD/L10/1SD values were significantly and highly correlated (R2 of 0.95 and 0.83, respectively, n = 42) with PODs previously used in human health assessments, with values similar to reported NOAELs. Specifically, the median ratio of BMDs10/1SD:NOAELs was 1.96, and the median ratio of BMDLs10/1SD:NOAELs was 0.89. We also observed a significant trend of increasing model viability with increasing number of dose groups. Conclusions: BMD/L10/1SD values can be calculated in a standardized way for use in health assessments on a large number of chemicals and critical effects. This facilitates the exploration of health effects across multiple studies of a given chemical or, when chemicals need to be compared, providing greater transparency and efficiency than current approaches. Citation: Wignall JA, Shapiro AJ, Wright FA, Woodruff TJ, Chiu WA, Guyton KZ, Rusyn I. 2014. Standardizing benchmark dose calculations to improve science-based decisions in human health assessments. Environ Health

  20. The ecosystem models used for dose assessments in SR-Can

    Energy Technology Data Exchange (ETDEWEB)

    Avila, Rodolfo [Facilia AB, Bromma (Sweden)

    2006-11-15

    chronic contamination. From the simulations for the different release cases, activity concentrations in water and soil are obtained and then multiplied with the aggregated transfer factors to obtain concentrations in food products. For terrestrial ecosystems, the aggregated transfer factors in Becquerel per Kilogram of edible carbon in the food are used to calculate the activity intake and from this the effective dose rate per unit release to an adult individual. For aquatic ecosystems, only doses from the ingestion of water (for lakes) and food (for sea and lakes) are considered, as previous assessments have shown that in these types of ecosystems other exposure pathways give a very low contribution to the total doses. A sensitivity analysis of the ecosystem models is presented in the report, identifying which parameters have the largest effect on the simulation endpoints of interest. The endpoints considered are the fraction of the release that is retained in the ecosystem, the activity concentrations in soil, water and sediments, and the total dose rates from external exposure, inhalation, and ingestion of water and food. These endpoints are evaluated at different times within the simulation and a sensitivity analysis using the Morris method is carried out. For some of the scenarios considered in SR-Can, the LDF concept is not applicable. One of these scenarios comprises the contamination of ground caused by inadvertent drilling into the repository. Doses which would arise for a family using this contaminated ground for housing and food production are estimated. The other scenario which is assessed separately is the release of C-14 and Rn-222 from the repository in gaseous form, entering the biosphere via soil as a diffuse source. Pathways considered are doses from ingestion of C-14 and from inhalation of C-14 and Rn-222 outdoors as well as indoors. For these scenarios, specific dose calculations were carried out. The methods applied for these calculations and the

  1. Three years of seasonal dose assessment from outdoors gamma exposure in Sao Paulo city, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, Janete C.G.G.; Sanches, Matias P.; Betti, Flavio; Pecequilo, Brigitte R.S., E-mail: janetegc@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Measurements of external (outdoors) gamma exposure from natural background radiation have been used to estimate the average annual doses in Sao Paulo city. Twelve monitoring stations were placed in different regions of the town including both urban (where building materials are present) and outskirts areas. Seasonally surveys observing the four seasons from 2008 to 2010 have been carried out. The data were drawn from a 3-month sampling using the thermoluminescent dosimetry. The effective doses values are quite similar (slightly higher during the winter), so it can be considered that these results are not under significant influence (or variability) of seasonal environmental conditions like temperature, wind or rain. Dose values over the three years period, from Vila Carrao district, exclusively an urban location with mostly no green areas, present the highest values, while the lower values were always obtained for Tucuruvi district, near the biggest urban forest, Parque Estadual da Cantareira. Over the assessed period, the mean of the average annual effective doses was 1.3 {+-} 0.1 mSv.y{sup -1}. For the same period, the average annual background from nuclear and radioactive facility at IPEN was 0.75 {+-} 0.12 mSv.y{sup -1}. (author)

  2. Assessment of the exposure to and dose from radon decay products in normally occupied homes

    Energy Technology Data Exchange (ETDEWEB)

    Hopke, P.K.; Jensen, B.; Li, C.S.; Montassier, N.; Wasiolek, P. [Clarkson Univ., Potsdam, NY (United States); Cavallo, A.J.; Gatsby, K.; Socolow, R.H. [Princeton Univ., NJ (United States); James, A.C. [Pacific Northwest Lab., Richland, WA (United States)

    1995-05-01

    The exposure to radon decay products has been assessed in seven homes in the northeastern United States and southeastern Canada. In two of the houses, there was a single individual who smoked cigarettes. There were a variety of heating and cooking appliances among these homes. These studies have provide 565 measurements of the activity-weighted size distributions in these houses. The median value for the equilibrium factor was 0.408 as compared with the previously employed value of 0.50. Using the recently adopted ICRP lung deposition and dosimetry model, the hourly equivalent lung dose rate per unit, radon exposure was estimated for each measured size distribution. Differences between houses with smokers present and absent were noted in the exposure conditions, but the resulting dose rate per unit of radon gas concentration was essentially the same for the two groups. Expressed in terms of ICRP`s unit of effective dose for members of the public, the mean dose rate conversion coefficient with respect to radon gas concentration found in this study was 3.8 nSv h{sup -} Bq{sup -} m{sup -3}. 26 refs., 8 figs., 3 tabs.

  3. Assessing small-volume spinal cord dose for repeat spinal stereotactic body radiotherapy treatments

    Science.gov (United States)

    Ma, Lijun; Kirby, Neil; Korol, Renee; Larson, David A.; Sahgal, Arjun

    2012-12-01

    Spinal cord biologically effective dose (BED) limits are critical to safe spine stereotactic body radiotherapy (SBRT) delivery. In particular, when repeating SBRT to the same site, the problem of adding non-uniform BED distributions within small volumes of spinal cord has yet to be solved. We report a probability-based generalized BED (gBED) model to guide repeat spine SBRT treatment planning. The gBED was formulated by considering the sequential damaging probabilities of repeat spine SBRT treatments. Parameters from the standard linear-quadratic model, such as α/β = 2 Gy for the spinal cord, were applied. We tested the model based on SBRT specific spinal cord tolerance using a simulated and ten clinical repeat SBRT cases. The gBED provides a consistent solution for superimposing non-uniform dose distributions from different fractionation schemes, analogous to the BED for uniform dose distributions. Based on ten clinical cases, the gBED was observed to eliminate discrepancies in the cumulative BED of approximately 5% to 20% within small volumes (e.g. 0.1-2.0 cc) of spinal cord, as compared to a conventional calculation method. When assessing spinal cord tolerance for repeat spinal SBRT treatments, caution should be exercised when applying conventional BED calculations for small volumes of spinal cord irradiated, and the gBED potentially provides more conservative and consistently derived dose surrogates to guide safe treatment planning and treatment outcome modeling.

  4. Dose-to-dose variations with single packages of counterfeit medicines and adulterated dietary supplements as a potential source of false negatives and inaccurate health risk assessments.

    Science.gov (United States)

    Venhuis, B J; Zwaagstra, M E; Keizers, P H J; de Kaste, D

    2014-02-01

    In this report, we show three examples of how the variability in dose units in single packages of counterfeit medicines and adulterated dietary supplements may contribute to a false negative screening result and inaccurate health risk assessments. We describe a counterfeit Viagra 100mg blister pack and a box of an instant coffee both containing dose units with and without an active pharmaceutical ingredient (API). We also describe a purportedly herbal slimming product with capsules that mutually differed in API and impurities. The adulterated dietary supplements contained sibutramine, benzyl-sibutramine, N-desmethyl-sibutramine (DMS), N,N-didesmethyl-sibutramine (DDMS) and several other related impurities. Counterfeit medicines and adulterated dietary supplements are a health risk because their quality is unreliable. Health risks are even greater when such unreliability extends to fundamental differences between dose units in one package. Because dose-to-dose variability for these products is unpredictable, the confidence interval of a sample size is unknown. Consequently, the analyses of a selection of dose units may not be representative for the package. In the worst case, counterfeit or unauthorised medicines are not recognised as such or a health risk is not identified. In order to reduce erroneous results particular care should be taken when analysing a composite of dose units, when finding no API in a dietary supplement and when finding conformity in a suspect counterfeit medicine. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. ACUTRI: a computer code for assessing doses to the general public due to acute tritium releases

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Sumi; Noguchi, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Ryufuku, Susumu; Sasaki, Toshihisa; Kurosawa, Naohiro [Visible Information Center, Inc., Tokai, Ibaraki (Japan)

    2002-11-01

    Tritium, which is used as a fuel of a D-T burning fusion reactor, is the most important radionuclide for the safety assessment of a nuclear fusion experimental reactor such as ITER. Thus, a computer code, ACUTRI, which calculates the radiological impact of tritium released accidentally to the atmosphere, has been developed, aiming to be of use in a discussion of licensing of a fusion experimental reactor and an environmental safety evaluation method in Japan. ACUTRI calculates an individual tritium dose based on transfer models specific to tritium in the environment and ICRP dose models. In this calculation it is also possible to analyze statistically on meteorology in the same way as a conventional dose assessment method according to the meteorological guide of the Nuclear Safety Commission of Japan. A Gaussian plume model is used for calculating the atmospheric dispersion of tritium gas (HT) and/or tritiated water (HTO). The environmental pathway model in ACUTRI considers the following internal exposures: inhalation from a primary plume (HT and/or HTO) released from the facilities and inhalation from a secondary plume (HTO) reemitted from the ground following deposition of HT and HTO. This report describes an outline of the ACUTRI code, a user guide and the results of test calculation. (author)

  6. Evolving Adjustments to External (Gamma) Slope Factors for CERCLA Risk and Dose Assessments - 12290

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Stuart [U.S. Environmental Protection Agency (United States)

    2012-07-01

    To model the external exposure pathway in risk and dose assessments of radioactive contamination at Superfund sites, the U.S. Environmental Protection Agency (EPA) uses slope factors (SFs), also known as risk coefficients, and dose conversion factors (DCFs). Without any adjustment these external radiation exposure pathways effectively assumes that an individual is exposed to a source geometry that is effectively an infinite slab. The concept of an 'infinite slab' means that the thickness of the contaminated zone and its aerial extent are so large that it behaves as if it were infinite in its physical dimensions. EPA has been making increasingly complex adjustments to account for the extent of the contamination and its corresponding radiation field to provide more accurate risk and dose assessment modeling when using its calculators. In most instances, the more accurate modeling results derived from these gamma adjustments are less conservative. The notable exception are for some radionuclides in rooms with contaminated walls, ceiling, and floors, and the receptor is in location of the room with the highest amount of radiation exposure, usually the corner of small rooms and the center of large conference rooms. (authors)

  7. Aldrin and dieldrin: a reevaluation of the cancer and noncancer dose-response assessments.

    Science.gov (United States)

    Hooker, Eric P; Fulcher, Keri G; Gibb, Herman J

    2014-05-01

    The dose-response analyses of cancer and noncancer health effects of aldrin and dieldrin were evaluated using current methodology, including benchmark dose analysis and the current U.S. Environmental Protection Agency (U.S. EPA) guidance on body weight scaling and uncertainty factors. A literature review was performed to determine the most appropriate adverse effect endpoints. Using current methodology and information, the estimated reference dose values were 0.0001 and 0.00008 mg/kg-day for aldrin and dieldrin, respectively. The estimated cancer slope factors for aldrin and dieldrin were 3.4 and 7.0 (mg/kg-day)(-1), respectively (i.e., about 5- and 2.3-fold lower risk than the 1987 U.S. EPA assessments). Because aldrin and dieldrin are no longer used as pesticides in the United States, they are presumed to be a low priority for additional review by the U.S. EPA. However, because they are persistent and still detected in environmental samples, quantitative risk assessments based on the best available methods are required. Recent epidemiologic studies do not demonstrate a causal association between aldrin and dieldrin and human cancer risk. The proposed reevaluations suggest that these two compounds pose a lower human health risk than currently reported by the U.S. EPA. © 2013 Society for Risk Analysis.

  8. Evaluation of intracranial aneurysm coil embolization in phantoms and patients using a high resolution microangiographic fluoroscope (MAF)

    Science.gov (United States)

    Ionita, Ciprian N.; Jain, Amit; Loughran, Brendan; Swetadri Vasan, S. N.; Bednarek, Daniel R.; Levy, Elad; Siddiqui, Adnan H.; Snyder, Kenneth V.; Hopkins, L. N.; Rudin, Stephen

    2012-03-01

    Intracranial aneurysm (IA) embolization using Gugliemi Detachable Coils (GDC) under x-ray fluoroscopic guidance is one of the most important neuro-vascular interventions. Coil deposition accuracy is key and could benefit substantially from higher resolution imagers such as the micro-angiographic fluoroscope (MAF). The effect of MAF guidance improvement over the use of standard Flat Panels (FP) is challenging to assess for such a complex procedure. We propose and investigate a new metric, inter-frame cross-correlation sensitivity (CCS), to compare detector performance for such procedures. Pixel (P) and histogram (H) CCS's were calculated as one minus the cross-correlation coefficients between pixel values and histograms for the region of interest at successive procedure steps. IA treatment using GDC's was simulated using an anthropomorphic head phantom which includes an aneurysm. GDC's were deposited in steps of 3 cm and the procedure was imaged with a FP and the MAF. To measure sensitivity to detect progress of the procedure by change in images of successive steps, an ROI was selected over the aneurysm location and pixel-value and histogram changes were calculated after each step. For the FP, after 4 steps, the H and P CCSs between successive steps were practically zero, indicating that there were no significant changes in the observed images. For the MAF, H and P CCSs were greater than zero even after 10 steps (30 cm GDC), indicating observable changes. Further, the proposed quantification method was applied for evaluation of seven patients imaged using the MAF, yielding similar results (H and P CCSs greater than zero after the last GDC deposition). The proposed metric indicates that the MAF can offer better guidance during such procedures.

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

    Science.gov (United States)

    2005-06-01

    sample sources to be exfoliated cells, body fluids such as blood and saliva, and breath. Collection of tissues and other body fluids requiring risky...M.B., and Miller, A . C . , 2001. “Radiation exposure assessment using cytological and molecular biomarkers,” Radiat. Prot. Dosimetry 9 7, 17–23

  10. 28 CFR 552.13 - X-ray, major instrument, fluoroscope, or surgical intrusion.

    Science.gov (United States)

    2010-07-01

    ... INSTITUTIONAL MANAGEMENT CUSTODY Searches of Housing Units, Inmates, and Inmate Work Areas § 552.13 X-ray, major... 28 Judicial Administration 2 2010-07-01 2010-07-01 false X-ray, major instrument, fluoroscope, or... reasons only, with the inmate's consent. (b) The institution physician may authorize use of an X-ray...

  11. Combined CT and fluoroscopic guidance of balloon kyphoplasty versus fluoroscopy-only procedures

    Energy Technology Data Exchange (ETDEWEB)

    Amoretti, Nicolas; Marcy, Pierre-Yves; Lesbats-Jacquot, Virginie; Fonquerne, Marie-Eve; Hericord, Olivier; Maratos, Yvonne [Centre Hospitalier Universitaire de Nice, Service de Radiologie, Nice (France); Hovorka, Istvan [Centre Hospitalier Universitaire de Nice, Spine Surgery Department, Nice (France); Roux, Christian; Euller-Ziegler, Liana [Centre Hospitalier Universitaire de Nice, Rheumatology Department, Nice (France)

    2009-07-15

    To evaluate the performance of combined (computed tomography (CT) and fluoroscopic) guidance of balloon kyphoplasty in comparison to fluoroscopic guidance alone. Forty-one kyphoplasties were performed between January 2005 and March 2006 according to two different protocols. Study group 1 consisted of 20 consecutive patients with 20 balloon kyphoplasty procedures under dual guidance (CT scan and fluoroscopy) for osteoporotic or traumatic vertebral fractures. Study group 2 consisted of 21 consecutive patients in whom kyphoplasty was performed with fluoroscopy alone. Visualization of the pedicles, the final of the balloon position, and cement distribution were evaluated(1 - poor, 2 - intermediate, 3 - good). Combined use of CT and fluoroscopy (group 1) was superior in identifying the pedicles (100% versus 66.7%, p = 0.009) and balloon placement (100% versus 71.4%, p = 0.02) but not in monitoring of cement distribution within the vertebral body (100% versus 90.5%, p = 0.49). The difference between the two groups was more pronounced in the thoracic spine than in the lumbar spine. CT/fluoroscopic guidance of kyphoplasty combines safe CT-guided insertion of the osteointroducers and balloons as well as fluoroscopic real-time monitoring of polymethylmethacrylate injection. (orig.)

  12. Numerical system utilising a Monte Carlo calculation method for accurate dose assessment in radiation accidents.

    Science.gov (United States)

    Takahashi, F; Endo, A

    2007-01-01

    A system utilising radiation transport codes has been developed to derive accurate dose distributions in a human body for radiological accidents. A suitable model is quite essential for a numerical analysis. Therefore, two tools were developed to setup a 'problem-dependent' input file, defining a radiation source and an exposed person to simulate the radiation transport in an accident with the Monte Carlo calculation codes-MCNP and MCNPX. Necessary resources are defined by a dialogue method with a generally used personal computer for both the tools. The tools prepare human body and source models described in the input file format of the employed Monte Carlo codes. The tools were validated for dose assessment in comparison with a past criticality accident and a hypothesized exposure.

  13. RADON AND PROGENY SOURCED DOSE ASSESSMENT OF SPA EMPLOYEES IN BALNEOLOGICAL SITES.

    Science.gov (United States)

    Uzun, Sefa Kemal; Demiröz, Işık

    2016-09-01

    This study was conducted in the scope of IAEA project with the name 'Establishing a Systematic Radioactivity Survey and Total Effective Dose Assessment in Natural Balneological Sites' (TUR/9/018), at the Health Physics department of Sarayköy Nuclear Research and Training Center (SANAEM). The aim of this study is estimation of radon and progeny sourced effective dose for the people who are working at the spa facilities by measuring radon activity concentration (RAC) at the ambient air of indoor spa pools and dressing rooms. As it is known, the source of the radon gas is the radium content of the earth crust. Therefore, thermal waters coming from ground may contain dissolved radon and the radon can diffuse water to air. So the ambient air of spa pools can contain serious RAC that depends on a lot of parameters. In this regard, RAC measurements were executed at the 70 spa facilities in Turkey. The measurements were done with both active and passive methods at ambient air of spa pools and dressing rooms. Thus, active measurements were carried out by using the Alphaguard(®) with diffusion mode during half an hour, and passive measurements were carried out by using the humidity resistive CR-39 radon detectors during 2 months. Results show that RAC values at ambient air of spa pools varies between 13 Bq m(-3) and 10 kBq m(-3) Because long-term measurements are more reliable, if it is available, for dose calculations passive radon measurements (with CR-39 detectors) at ambient air of spa pools and dressing rooms were used, otherwise active measurement results were used. With the measurement by the conversion coefficients of ICRP 65 and occupational data of the employees has got from questionary forms, effective dose values were calculated. According to the calculations, spa employees are exposed to annual average dose between 0.05 and 29 mSv because of radon and progeny.

  14. Dose Assessment of Eye and Its Components in Proton Therapy by Monte Carlo Method

    Directory of Open Access Journals (Sweden)

    Marzieh Tavakol

    2014-04-01

    Full Text Available Introduction Proton therapy is used to treat malignant tumors such as melanoma inside the eye. Proton particles are adjusted according to various parameters such as tumor size and position and patient’s distance from the proton source. The purpose of this study was to assess absorbed doses in eyes and various tumors found in the area of sclera and choroid and the adjacent tissues in radiotherapy while changing most important proton therapy parameters such as moderators thickness (1.5-1.9 cm, exposure radius (0.5-0.8 cm, and proton energy beam (53.5-65 MeV. Materials and Methods A proton therapy system of Laboratori Nazionali del Sud-INFNwas simulated by Monte Carlo method. Moreover, the eye and its components were simulated using concentric spheres. To obtain a more accurate results, real density of eye components such as cornea and lens, were applied for simulation. Then, the absorbed dose of eye and eye tumor, in choroid and sclera areas, were calculated by Monte Carlo method. Results The absorbed dose in tumoral region of eye was calculated to be about 12.5 ±0.006Gy in one day with energy 62 MeV for a therapy session, which is suitable for treatment. However, normal eye cells received at most 11.01 Gy which is high. Conclusion The amount of absorbed dose in tumoral cells is noticeable. Therefore, accurate treatment planning, patient immobility and fine calibration of proton-therapy system and its simulator are very important to reduce the absorbed dose of healthy cells.

  15. Screening level dose assessment of aquatic biota downstream of the Marcoule nuclear complex in southern France.

    Science.gov (United States)

    St-Pierre, S; Chambers, D B; Lowe, L M; Bontoux, J G

    1999-09-01

    Aquatic biota in the Rhone River downstream of the Marcoule nuclear complex in France are exposed to natural sources of radiation and to radioactivity released from the Marcoule complex. A simple conservative screening level model was used to estimate the range of concentrations in aquatic media (water, sediments, and aquatic organisms) of both artificial and natural radionuclides and the consequent absorbed (whole body) dose rates for aquatic organisms. Five categories of aquatic organisms were studied, namely, submerged aquatic plants (phanerogam), non-bottom-feeding fish, bottom-feeding fish, mollusca, and fish-eating birds. The analysis was based on the radionuclide concentrations reported in four consecutive annual radioecological monitoring reports published by French agencies with nuclear regulatory responsibilities. The results of this assessment were used to determine, qualitatively, the magnitude of any potential health impacts on each of the five categories of aquatic organisms studied. The range of dose rate estimates ranged over three orders of magnitude, with maximum dose rates estimated to be in the order of 1 to 10 microGy h(-1). These maximum dose rates are a factor 40 or more below the international guideline intended to ensure the protection of aquatic populations (about 400 microGy h(-1)), and a factor ten or more below the level which may trigger the need for a more detailed evaluation of potential ecological consequences to the exposed populations (about 100 microGy h(-1)). As a result, chronic levels of radioactivity, artificial and natural, measured in aquatic media downstream of Marcoule are unlikely to result in adverse health impacts on the categories and species of aquatic organisms studied. Thus, based on the screening level analysis discussed in this paper, a more detailed evaluation of the dose rates does not appear to be warranted.

  16. Performance assessment of the BEBIG MultiSource high dose rate brachytherapy treatment unit.

    Science.gov (United States)

    Palmer, Antony; Mzenda, Bongile

    2009-12-21

    A comprehensive system characterisation was performed of the Eckert & Ziegler BEBIG GmbH MultiSource High Dose Rate (HDR) brachytherapy treatment unit with an (192)Ir source. The unit is relatively new to the UK market, with the first installation in the country having been made in the summer of 2009. A detailed commissioning programme was devised and is reported including checks of the fundamental parameters of source positioning, dwell timing, transit doses and absolute dosimetry of the source. Well chamber measurements, autoradiography and video camera analysis techniques were all employed. The absolute dosimetry was verified by the National Physical Laboratory, UK, and compared to a measurement based on a calibration from PTB, Germany, and the supplied source certificate, as well as an independent assessment by a visiting UK centre. The use of the 'Krieger' dosimetry phantom has also been evaluated. Users of the BEBIG HDR system should take care to avoid any significant bend in the transfer tube, as this will lead to positioning errors of the source, of up to 1.0 mm for slight bends, 2.0 mm for moderate bends and 5.0 mm for extreme curvature (depending on applicators and transfer tube used) for the situations reported in this study. The reason for these errors and the potential clinical impact are discussed. Users should also note the methodology employed by the system for correction of transit doses, and that no correction is made for the initial and final transit doses. The results of this investigation found that the uncorrected transit doses lead to small errors in the delivered dose at the first dwell position, of up to 2.5 cGy at 2 cm (5.6 cGy at 1 cm) from a 10 Ci source, but the transit dose correction for other dwells was accurate within 0.2 cGy. The unit has been mechanically reliable, and source positioning accuracy and dwell timing have been reproducible, with overall performance similar to other existing HDR equipment. The unit is capable of high

  17. Assessment of the Technologies for Molecular Biodosimetry for Human Low-Dose Radiation Exposure Symposium

    Energy Technology Data Exchange (ETDEWEB)

    Matthew A. Coleman Ph.D.; Narayani Ramakrishnan, Ph.D.; Sally A. Amundson; James D. Tucker, Ph.D.; Stephen D. Dertinger, Ph.D.; Natalia I. Ossetrova, Ph.D.; Tao Chen

    2009-11-16

    Exposure to ionizing radiation produces few immediate outwardly-visible clinical signs, yet, depending on dose, can severely damage vital physiological functions within days to weeks and produce long-lasting health consequences among survivors. In the event of a radiological accident, the rapid evaluation of the individual absorbed dose is paramount to discriminate the worried but unharmed from those individuals who must receive medical attention. Physical, clinical and biological dosimetry are usually combined for the best dose assessment. However, because of the practical limits of physical and clinical dosimetry, many attempts have been made to develop a dosimetry system based on changes in biological parameters, including techniques for hematology, biochemistry, immunology, cytogenetics, etc. Lymphocyte counts and chromosome aberrations analyses are among the methods that have been routinely used for estimating radiation dose. However, these assays require several days to a week to be completed and therefore cannot be used to obtain a fast estimate of the dose during the first few days after exposure when the information would be most critical for identifying victims of radiation accidents who could benefit the most by medical intervention. The steadily increasing sophistication in our understanding of the early biochemical responses of irradiated cells and tissues provides the opportunity for developing mechanism-based biosignatures of exposure. Compelling breakthroughs have been made in the technologies for genome-scale analysis of cellular transcriptional and proteomic profiles. There have also been major strides in the mechanistic understanding of the early events in DNA damage and radiation damage products, as well as in the cellular pathways that lead to radiation injury. New research with genomic- and proteomic-wide tools is showing that within minutes to hours after exposure to ionizing radiation protein machines are modified and activated, and large

  18. "The Dose Makes the Poison": Informing Consumers About the Scientific Risk Assessment of Food Additives.

    Science.gov (United States)

    Bearth, Angela; Cousin, Marie-Eve; Siegrist, Michael

    2016-01-01

    Intensive risk assessment is required before the approval of food additives. During this process, based on the toxicological principle of "the dose makes the poison,ˮ maximum usage doses are assessed. However, most consumers are not aware of these efforts to ensure the safety of food additives and are therefore sceptical, even though food additives bring certain benefits to consumers. This study investigated the effect of a short video, which explains the scientific risk assessment and regulation of food additives, on consumers' perceptions and acceptance of food additives. The primary goal of this study was to inform consumers and enable them to construct their own risk-benefit assessment and make informed decisions about food additives. The secondary goal was to investigate whether people have different perceptions of food additives of artificial (i.e., aspartame) or natural origin (i.e., steviolglycoside). To attain these research goals, an online experiment was conducted on 185 Swiss consumers. Participants were randomly assigned to either the experimental group, which was shown a video about the scientific risk assessment of food additives, or the control group, which was shown a video about a topic irrelevant to the study. After watching the video, the respondents knew significantly more, expressed more positive thoughts and feelings, had less risk perception, and more acceptance than prior to watching the video. Thus, it appears that informing consumers about complex food safety topics, such as the scientific risk assessment of food additives, is possible, and using a carefully developed information video is a successful strategy for informing consumers.

  19. Equivalent dose, effective dose and risk assessment from panoramic radiography to the critical organs of head and neck region

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Bong Hae; Nah, Kyung Soo [Dept. of Dental Radiology, College of Dentistry, Pusan National University, Pusan (Korea, Republic of); Lee, Ae Ryeon [Dept. of Pediatric Dentistry, College of Dentistry, Pusan National University, Pusan (Korea, Republic of)

    1995-08-15

    The purpose of this study was to evaluate the equivalent and effective dose, and estimate radiation risk to the critical organs of head and neck region from the use of adult and child mode in panoramic radiography. The results were as follows. 1. The salivary glands showed the highest equivalent and effective dose in adult and child mode. The equivalent and effective dose in adult mode were 837 {mu}Sv and 20.93 {mu}Sv, those in child mode were 462 {mu}Sv and 11.54 {mu}Sv, respectively. 2. Total effective doses to the critical head and neck organs were estimated 34.2l {mu}Sv in adult mode, 20.14 {mu}Sv in child mode. From these data, the probabilities of stochastic effect from adult and child mode were 2.50xl0{sup -6} and 1.47x10{sup -6} 3. The other remainder showed the greatest risk of fatal cancer. The risk estimate were 4.5 and 2.7 fatal malignancies in adult and child mode from million examinations. The bone marrow and thyroid gland showed about 0.1 fatal cancer in adult. and child mode from these examinations.

  20. Development and Validation of a Questionnaire to Assess Carbohydrate and Insulin-Dosing Knowledge in Youth With Type 1 Diabetes

    OpenAIRE

    Koontz, Michaela B.; Cuttler, Leona; Palmert, Mark R; O'Riordan, MaryAnn; BORAWSKI, ELAINE A.; McConnell, Judy; Kern, Elizabeth O.

    2009-01-01

    OBJECTIVE The American Diabetes Association advocates insulin regimens for youth with type 1 diabetes that involve adjusting insulin dose based on carbohydrate intake and blood glucose level. Implementing these regimens requires knowledge about carbohydrate content of foods and subsequent calculations of insulin dose, skills that may be difficult to gauge in practice. Therefore, we sought to develop and validate a questionnaire, the PedCarbQuiz (PCQ), to assess carbohydrate and insulin-dosing...

  1. SU-E-T-616: Plan Quality Assessment of Both Treatment Planning System Dose and Measurement-Based 3D Reconstructed Dose in the Patient

    Energy Technology Data Exchange (ETDEWEB)

    Olch, A [University of Southern California, Los Angeles, CA (United States)

    2015-06-15

    Purpose: Systematic radiotherapy plan quality assessment promotes quality improvement. Software tools can perform this analysis by applying site-specific structure dose metrics. The next step is to similarly evaluate the quality of the dose delivery. This study defines metrics for acceptable doses to targets and normal organs for a particular treatment site and scores each plan accordingly. The input can be the TPS or the measurement-based 3D patient dose. From this analysis, one can determine whether the delivered dose distribution to the patient receives a score which is comparable to the TPS plan score, otherwise replanning may be indicated. Methods: Eleven neuroblastoma patient plans were exported from Eclipse to the Quality Reports program. A scoring algorithm defined a score for each normal and target structure based on dose-volume parameters. Each plan was scored by this algorithm and the percentage of total possible points was obtained. Each plan also underwent IMRT QA measurements with a Mapcheck2 or ArcCheck. These measurements were input into the 3DVH program to compute the patient 3D dose distribution which was analyzed using the same scoring algorithm as the TPS plan. Results: The mean quality score for the TPS plans was 75.37% (std dev=14.15%) compared to 71.95% (std dev=13.45%) for the 3DVH dose distribution. For 3/11 plans, the 3DVH-based quality score was higher than the TPS score, by between 0.5 to 8.4 percentage points. Eight/11 plans scores decreased based on IMRT QA measurements by 1.2 to 18.6 points. Conclusion: Software was used to determine the degree to which the plan quality score differed between the TPS and measurement-based dose. Although the delivery score was generally in good agreement with the planned dose score, there were some that improved while there was one plan whose delivered dose quality was significantly less than planned. This methodology helps evaluate both planned and delivered dose quality. Sun Nuclear Corporation has

  2. Biological shielding assessment and dose rate calculation for a neutron inspection portal

    Science.gov (United States)

    Donzella, A.; Bonomi, G.; Giroletti, E.; Zenoni, A.

    2012-04-01

    With reference to the prototype of neutron inspection portal built and successfully tested in the Rijeka seaport (Croatia) within the EURITRACK (EURopean Illicit Trafficking Countermeasures Kit) project, an assessment of the biological shielding in different set-up configurations of a future portal has been calculated with MCNP Monte Carlo code in the frame of the Eritr@C (European Riposte against Illicit TR@ffiCking) project. In the configurations analyzed the compliance with the dose limits for workers and the population stated by the European legislation is provided by appropriate shielding of the neutron sources and by the delimitation of a controlled area.

  3. Assessment of a low dose of IV midazolam used orally for conscious sedation in pediatric dentistry

    OpenAIRE

    M. Mortazavi; Pourhashemi SJ; Khosravi, M. B.; S Ashtari; F. Ghaderi

    2009-01-01

    Background and the purpose of the study: Midazolam is preferably used in pediatric dentistry for quick onset of action and recovery. The aim of this prospective, observer-blind and placebo-controlled study was to assess the efficacy of a low dose of oral midazolam in modification of  the behavior of young pediatric dental patients. Methods: Forty children aged 3 to 5 years who displayed ratings 1 or 2 on the Frankl Scale and  were healthy by the American Society of Anesthesi...

  4. A Review of Models for Dose Assessment Employed by SKB in the Renewed Safety Assessment for SFR 1

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, George [Imperial College of Science Technology and Medicine (United Kingdom)

    2002-09-01

    This document provides a critical review, on behalf of SSI, of the models employed by the Swedish Nuclear Fuel and Waste Management Co (SKB) for dose assessment in the renewed safety assessment for the final repository for radioactive operational waste (SFR 1) in Forsmark, Sweden. The main objective of the review is to examine the models used by SKB for radiological dose assessment in a series of evolving biotopes in the vicinity of the Forsmark repository within a time frame beginning in 3000 AD and extending beyond 7500 AD. Five biosphere models (for coasts, lakes, agriculture, mires and wells) are described in Report TR-01-04. The principal consideration of the review is to determine whether these models are fit for the purpose of dose evaluation over the time frames involved and in the evolving sequence of biotopes specified. As well as providing general observations and comments on the modelling approach taken, six specific questions are addressed, as follows. Are the assumptions underlying the models justifiable? Are all reasonably foreseeable environmental processes considered? Has parameter uncertainty been sufficiently and reasonably addressed? Have sufficient models been used to address all reasonably foreseeable biotopes? Are the transitions between biotopes modelled adequately (specifically, are initial conditions for developing biotopes adequately specified by calculations for subsiding biotopes)? Have all critical radionuclides been identified? It is concluded that, in general, the assumptions underlying most of the models are justifiable. The exceptions are a) the rather simplistic approach taken in the Coastal Model and b) the lack of consideration of wild foods and age-dependence when calculating exposures of humans to radionuclides via dietary pathways. Most foreseeable processes appear to have been accounted for within the constraints of the models used, although it is recommended that attention be paid to future climate states when considering

  5. Valdose program: methodologies for dose assessment in internal contamination, 1997 census; Programma valdose: metodologie di valutazione della dose da contaminazione interna, censimento 1997

    Energy Technology Data Exchange (ETDEWEB)

    Castellani, C.M.; Battisti, P.; Tarroni, G. [ENEA, Centro Ricerche `Ezio Clementel`, Bologna (Italy). Dip. Ambiente

    1998-12-31

    Dose assessment in internal dosimetry needs computational and interpretative tools that allow carrying out, as a first step, an evaluation of intake on the base of bioassay measurements or WBC measurements, and as a second step, dose evaluation on the base of estimated intake. In the frame of the MIDIA Co-ordination (WBC operating in Italy), in the first months of 1997 a census on methodologies for dose evaluation in internal contamination has been proposed. A technical form has been sent to all the WBC Centres allowing an accurate description of modalities used in each centre. 9 out of 17 centres sent the answers to the technical form in time. In this paper all the forms filled in are reported. A careful comparative evaluation of the answers has been made both for routine monitoring and for special monitoring. The various radionuclides present in the Italian reality, calculation methodologies both for intake and dose, hypotheses adopted for date, path and modalities of contaminations are also presented. Proposals for conforming to the methodology in Italy after the introduction of the models following ICRP 60 publication that are the base of the Euratom 96/29 Directive are also discussed. [Italiano] La valutazione di dose in contaminazione interna necessita di strumenti interpretativi che permettano di effettuare in una prima la valutazione dell`intake sulla base delle misure dei campioni biologici o del corpo intero (WBC), ed in una seconda fase la valutazione della dose sulla base dell`intake. All`interno del coordinamento MIDIA dei WBC operanti in Italia e` stato proposto, nel primo trimestre del 1997, un censimento sulle metodologie di valutazione di dose da contaminazione interna. Ai diversi centri e` stato inviato una scheda tecnica che, mediante un particolareggiato schema di domande, aiutava i diversi centri nella esposizione delle modalita` di valutazione di dose che ogni centro segue. 9 au 17 centri WBC operanti al momemnto in Italia hanno inviato la

  6. Dose assessment of SiC nanoparticle dispersions during in vitro assays

    Energy Technology Data Exchange (ETDEWEB)

    Mejia, Jorge, E-mail: jorge.mejiamendoza@unamur.be [University of Namur, Research Centre for the Physics of Matter and Radiation (LARN-PMR) NARILIS (Belgium); Piret, Jean-Pascal; Noeel, Florence [University of Namur, Research Unit in Cellular Biology (URBC) NARILIS (Belgium); Masereel, Bernard [University of Namur, Department of Pharmacy NAMEDIC, Namur Thrombosis and Homeostasis Center (NTHC) NARILIS (Belgium); Toussaint, Olivier [University of Namur, Research Unit in Cellular Biology (URBC) NARILIS (Belgium); Lucas, Stephane [University of Namur, Research Centre for the Physics of Matter and Radiation (LARN-PMR) NARILIS (Belgium)

    2013-08-15

    Here, we show that key physicochemical parameters of commercial Silicon Carbide nanoparticles, such as the primary particles of about 53 nm in size, the agglomerates size, and the surface composition, are considerably modified with respect to the pristine conditions, during in vitro assessment. The use of sample conditioning stages, such as the pre-dispersion in aqueous media and the subsequent dispersion in a culture medium specific to the in vitro assay, produce modifications as the absorption of N, C, and O, from the culture medium, in the nanoparticles surface. Our results show that the sedimented dose, fraction of sedimented NPs during incubation and consequently in contact with cells seeded at the bottom, of Silicon Carbide nanoparticles can be measured from the particle size distribution obtained using a centrifugal liquid sedimentation technique. It is underlined that the variations observed in the physicochemical properties are related to the in vitro assay conditions. Culture medium and incubation time are found to influence the most the sedimented dose and consequently the cells dose uptake.

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

    Energy Technology Data Exchange (ETDEWEB)

    Leggett, Richard Wayne [ORNL; Eckerman, Keith F [ORNL

    2010-03-01

    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. 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.

  8. Image quality and dose assessment in digital breast tomosynthesis: A Monte Carlo study

    Science.gov (United States)

    Baptista, M.; Di Maria, S.; Oliveira, N.; Matela, N.; Janeiro, L.; Almeida, P.; Vaz, P.

    2014-11-01

    Mammography is considered a standard technique for the early detection of breast cancer. However, its sensitivity is limited essentially due to the issue of the overlapping breast tissue. This limitation can be partially overcome, with a relatively new technique, called digital breast tomosynthesis (DBT). For this technique, optimization of acquisition parameters which maximize image quality, whilst complying with the ALARA principle, continues to be an area of considerable research. The aim of this work was to study the best quantum energies that optimize the image quality with the lowest achievable dose in DBT and compare these results with the digital mammography (DM) ones. Monte Carlo simulations were performed using the state-of-the-art computer program MCNPX 2.7.0 in order to generate several 2D cranio-caudal (CC) projections obtained during an acquisition of a standard DBT examination. Moreover, glandular absorbed doses and photon flux calculations, for each projection image, were performed. A homogeneous breast computational phantom with 50%/50% glandular/adipose tissue composition was used and two compressed breast thicknesses were evaluated: 4 cm and 8 cm. The simulated projection images were afterwards reconstructed with an algebraic reconstruction tool and the signal difference to noise ratio (SDNR) was calculated in order to evaluate the image quality in DBT and DM. Finally, a thorough comparison between the results obtained in terms of SDNR and dose assessment in DBT and DM was performed.

  9. Transcatheter Mitral Paravalvular Leak Closure Facilitated by Preprocedural Cardiac CT for Simulation of Fluoroscopic Anatomy and Paravalvular Defect Localization.

    Science.gov (United States)

    Korsholm, Kasper; Mortensen, Ulrik; Jensen, Jesper Møller; Piazza, Nicolo; Thériault-Lauzier, Pascal; Nielsen-Kudsk, Jens Erik

    2017-02-01

    Paravalvular leakage (PVL) occurs in 6%-15% of cases after surgical heart valve replacement. A percutaneous approach is increasingly used to close PVLs as an alternative to repeat surgery. Computed tomography (CT) can be used for simulation of fluoroscopic cardiac anatomy. This technique allows preprocedural definition of optimal C-arm angulations and PVL localization in reference to fluoroscopic views. It is very helpful for guidewire crossing of the PVL and positioning of the closure device. We report a case with the first use of dedicated software for fluoroscopic simulation (FluoroCT) in transcatheter mitral PVL closure.

  10. DOSE ASSESSMENT FOR INTAKE OF TRITIATED WATER IN HUMANS: ROLE OF TRITIUM INCORPORATION IN ORGANIC MATTER

    Directory of Open Access Journals (Sweden)

    M. I. Balonov

    2016-01-01

    for two-compartment modeling. The recurrent model with tritiated water excretion was more adjusted to human physiology. Contribution of organically bound tritium to effective dose can be somewhat higher than that to absorbed dose defined in this work. The presented dose assessment system can be used when specified individual absorbed dose reconstruction in tissues is necessary following accidental intake of large tritium activities.

  11. Dose assessment from chronic exposure to industrial NORM in iron ore processing.

    Science.gov (United States)

    Dal Molin, Franck; Fisher, Raymond; Frost, David; Anderson, David R; Read, David

    2017-09-05

    Radiological exposures due to naturally occurring radioactive material (NORM) can occur during a wide range of work-related activities in the mineral processing and chemical industries. However, evaluation of such exposures in industrial settings remains a difficult exercise owing inter alia to the large number of personnel, operations and plants affected; assumptions that often have to be made concerning the actual duration and frequency of exposures; the complex chemistry and radioactive disequilibria involved and typically, the paucity of historical data. In our study, the challenges associated with assessing chronic exposure to fugitive dust enriched in 210Pb and 210Po and the determination of the associated internal dose by inhalation and ingestion are described by reference to a case study undertaken at an iron ore sintering plant between June 2013 and July 2015. The applicability of default dose coefficients and biokinetic models provided by the International Commission for Radiological Protection (ICRP) was verified by combining air and dust monitoring with information on the characteristics of the aerosols and in-vitro solubility experiments. The disparity between particulate matter 100 microns or less in diameter (PM100), particulate matter 10 microns or less in diameter (PM10) and 210Pb/210Po activity concentrations observed over the different monitoring campaigns and sampling locations confirmed that use of positional short-term monitoring surveys to extrapolate intake over a year was not appropriate and could lead to unrealistic intake and dose figures. Personal air sampling is more appropriate for estimating the dose in such situations, though it is not always practical and may collect insufficient quantities of material for radiochemical analysis; this is an important constraint when dealing with low specific activity materials. © 2017 IOP Publishing Ltd.

  12. Development of low-dose protocols for thin-section CT assessment of cystic fibrosis in pediatric patients.

    LENUS (Irish Health Repository)

    O'Connor, Owen J

    2010-12-01

    To develop low-dose thin-section computed tomographic (CT) protocols for assessment of cystic fibrosis (CF) in pediatric patients and determine the clinical usefulness thereof compared with chest radiography.

  13. PECULIARITIES OF CURRENT DOSE ASSESSMENT FOR CHILDREN LIVING IN THE TERRITORIES RADIOACTIVELY CONTAMINATED DUE TO THE CHERNOBYL ACCIDENT

    Directory of Open Access Journals (Sweden)

    A. V. Gromov

    2011-01-01

    Full Text Available The article outlines peculiarities of current dose assessment for the children living in the territories radioactively contaminated due to the Chernobyl accident. The results of annual exposure dose assessment for the children of various age groups and adult population of three subject territories of the Russian Federation referred to the zones of radioactive contamination are presented. A comparison of obtained estimations is done.

  14. Bayesian Analysis for Food-Safety Risk Assessment: Evaluation of Dose-Response Functions within WinBUGS

    OpenAIRE

    Williams, Michael S.; Ebel, Eric D.; Jennifer A Hoeting

    2011-01-01

    Bayesian methods are becoming increasingly popular in the field of food-safety risk assessment. Risk assessment models often require the integration of a dose-response function over the distribution of all possible doses of a pathogen ingested with a specific food. This requires the evaluation of an integral for every sample for a Markov chain Monte Carlo analysis of a model. While many statistical software packages have functions that allow for the evaluation of the integral, this functional...

  15. CANCER RISKS ATTRIBUTABLE TO LOW DOSES OF IONIZING RADIATION - ASSESSING WHAT WE REALLY KNOW?

    Science.gov (United States)

    Cancer Risks Attributable to Low Doses of Ionizing Radiation - What Do We Really Know?AbstractHigh doses of ionizing radiation clearly produce deleterious consequences in humans including, but not exclusively, cancer induction. At very low radiation doses the situatio...

  16. EcoDoses. Improving radiological assessment of doses to man from terrestrial ecosystems: A status report for the NKS-B activity 2006

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, S.; Andersson, K.G. (Technical Univ. of Denmark, Risoe National Lab. for Sustainable Energy, Roskilde (Denmark)); Thoerring, H.; Liland, A. (Norwegian Radiation Protection Authority (Norway)); Joensen, H.P. (Frooskaparsetur Foeroya, Faroe Islands, Torshavn (Denmark)); Isaksson, M. (Goeteborg Univ. (Sweden)); Saxen, R.; Kostiainen, E. (Radiation and Nuclear Safety Authority (STUK) (Finland)); Suolanen, V. (VTT Technical Research Centre of Finland, Espoo (Finland)); Palsson, S.E. (Geislavarnir rikisins (Iceland))

    2009-03-15

    The overall aim of the NKS-B EcoDoses activity is to improve the prediction of doses to humans from consumption of radioactively contaminated food. For this purpose, various published and unpublished datasets have been compiled and applied in developing refined parameterisation for existing food dose models. The ECOSYS model developed in Germany after the Chernobyl accident has been applied as the basis for the investigations. This model can be operated both with discrete releases adequately representing a nuclear power plant accident, and with continuous or multiple releases, as observed in the nuclear weapons testing period. The modelling has revealed that it is essential to ensure that case-specific values are applied for a range of parameters, adequately reflecting the actual conditions with respect to geology, season, climate and demography. In connection with this year's work on the activity, sensitivity studies have been conducted with the ECOSYS model, in which the influence on ingestion dose estimates of a number of parameters has been evaluated in relation to Faroese conditions. The importance of applying location specific data to estimate dose is pinpointed, and it is also concluded that dose predictions for a small and distinct area like the Faroese, where not all of the many parameters required to run ECOSYS optimally have been adequately assessed in recent years, can be associated with considerable uncertainty. A Finnish study has been made in relation to modelling of radiocaesium behaviour in lakes. This study was carried out using a compartmental model that is included as a module in the DETRA dose assessment tool. A total of nine different input parameters (distribution coefficients, run-off from the catchment, erosion from the catchment, sedimentation rate in the lakes, lake water exchange rate, and biological half-lives in four fish species) were varied, and particularly distribution coefficients and lake water exchange rates were

  17. The Art of Making Assessment Anti-Venom: Injecting Assessment in Small Doses to Create a Faculty Culture of Assessment

    Science.gov (United States)

    Kramer, Philip I.

    2009-01-01

    Many college faculty react to student outcomes assessment the way most people react when they see a rattlesnake within striking distance. Common faculty reactions to the perceived threat of assessment include metaphorically running away and throwing rocks or sticks at it. Like a hiker in the desert doing her best to avoid being struck when she…

  18. Personnel dose assessment due to the normal operations with the artificial radiation sources according to the data from the unified system of individual dose control (USIDC

    Directory of Open Access Journals (Sweden)

    Yu. I. Stepkin

    2016-01-01

    Full Text Available The aim of the study was personnel dose assessment due to the normal operations with the artificial radiation sources. The article is based on the data from the Unified System of Individual Dose Control and Voronezh Region’s radiation-hygienic passport. The data from No.1-DOZ “Information on personnel exposure doses under normal operation of technogenic ionizing radiation sources” and over a period of 2006-2010 years were analyzed. In 2006-2015, the number of organizations, which submitted form No.1-DOZ “Information on personnel exposure doses under normal operation of technogenic ionizing radiation sources”, increased from 175 to 229. In amount of the radiation facilities, Novovoronezh Nuclear Power Plant is the first. Novovoronezh NPP has 1512 sources, which amounts to 51,9% from all sources in Voronezh Region (2915. Health care facilities have 869 radiation sources or 29,8%. X-ray machines are the main part of these sources (844 health care facilities or 97,1% of all medical sources. Industrial sources occupy third place with 305 facilities or 10,5% of all considered sources. In 2015, according to the data from Voronezh Region’s radiation-hygienic passport, the number of “A” group personnel were 4237, the number of “B” group personnel were 2341. The average individual dose for personnel was over the range from 0.66 to 2.02 mSv. Collective dose was from 4.16 to 11.79 man-sieverts per year. The increase of number of the radiation sources has attended with the decrease of individual and collective doses. The most likely it is related to using the modern facilities. In 2015, the maximum value of the average individual dose of “A” group personnel was registered in Voronezh regional hospital (6.17 mSv y–1. There are medical facilities with unsealed and sealed sources in this hospital. In 2006-2015, the average individual doses of personnel of all radiation facilities that use radiation sources in Voronezh

  19. Quantitative and qualitative comparison of standard-dose and low-dose pediatric head computed tomography: a retrospective study assessing the effect of adaptive statistical iterative reconstruction.

    Science.gov (United States)

    Kilic, Koray; Erbas, Gonca; Guryildirim, Melike; Konus, Oznur Leman; Arac, Mehmet; Ilgit, Erhan; Isik, Sedat

    2013-01-01

    Our aim was to assess the effect of adaptive statistical iterative reconstruction (ASIR) on pediatric head computed tomography (CT) examinations. We retrospectively reviewed 305 pediatric head CT examinations. The study population consisted of standard dose (STD, n = 152) examinations reconstructed with filtered back projection and low dose (LD, n = 153) examinations reconstructed with 30% (LD30) and 0% (LD0) ASIR. We compared groups by means of radiation dose, noise measures, and visual grading. Student t test, 1-way analysis of variance test, and Mann-Whitney U test were used for statistical analysis. The dose in the LD30 group was significantly lower (29%) than that in the STD group (P < 0.001). The noise in the white matter (P < 0.001), SNR (P < 0.001), and subjective image noise (P = 0.044) was significantly better in the STD group than those in the LD30 group. There was no significant difference between LD30 and STD groups in the sharpness (P = 0.141), diagnostic acceptability (P = 0.079), and artifacts (P = 0.750) and contrast-to-noise ratio (P = 0.718). In conclusion, we found that a blend of 30% ASIR in a 16-slice multidetector CT produces diagnostically acceptable pediatric head CT examinations with a 29% less dose.

  20. Assessment of low-dose cisplatin as a model of nausea and emesis in beagle dogs, potential for repeated administration.

    Science.gov (United States)

    Kenward, Hannah; Pelligand, Ludovic; Elliott, Jonathan

    2014-08-01

    Cisplatin is a highly emetogenic cancer chemotherapy agent, which is often used to induce nausea and emesis in animal models. The cytotoxic properties of cisplatin also cause adverse events that negatively impact on animal welfare preventing repeated administration of cisplatin. In this study, we assessed whether a low (subclinical) dose of cisplatin could be utilized as a model of nausea and emesis in the dog while decreasing the severity of adverse events to allow repeated administration. The emetic, nausea-like behavior and potential biomarker response to both the clinical dose (70 mg/m2) and low dose (15 mg/m2) of cisplatin was assessed. Plasma creatinine concentrations and granulocyte counts were used to assess adverse effects on the kidneys and bone marrow, respectively. Nausea-like behavior and emesis was induced by both doses of cisplatin, but the latency to onset was greater in the low-dose group. No significant change in plasma creatinine was detected for either dose groups. Granulocytes were significantly reduced compared with baseline (P = 0.000) following the clinical, but not the low-dose cisplatin group. Tolerability of repeated administration was assessed with 4 administrations of an 18 mg/m2 dose cisplatin. Plasma creatinine did not change significantly. Cumulative effects on the granulocytes occurred, they were significantly decreased (P = 0.03) from baseline at 3 weeks following cisplatin for the 4th administration only. Our results suggest that subclinical doses (15 and 18 mg/m2) of cisplatin induce nausea-like behavior and emesis but have reduced adverse effects compared with the clinical dose allowing for repeated administration in crossover studies.

  1. ASSESSMENT OF EFFECTIVE DOSE FROM CONE BEAM CT IMAGING IN SPECT/CT EXAMINATION IN COMPARISON WITH OTHER MODALITIES.

    Science.gov (United States)

    Tonkopi, Elena; Ross, Andrew A

    2016-12-01

    The aim of this study was to assess radiation dose from the cone beam computed tomography (CBCT) component of single photon emission tomography/computed tomography (SPECT/CT) examinations and to compare it with the radiopharmaceutical related dose as well as dose from multidetector computed tomography (MDCT). Effective dose (ED) from computed tomography (CT) was estimated using dose-length product values and anatomy-specific conversion factors. The contribution from the SPECT component was evaluated using ED per unit administered activity for the radiopharmaceuticals listed in the International Commission on Radiological Protection Publications 80 and 106. With the exception of cardiac studies (0.11 mSv), the CBCT dose (3.96-6.04 mSv) was similar to that from the radiopharmaceutical accounting for 29-56 % of the total ED from the examination. In comparison with MDCT examinations, the CBCT dose was 48 and 42 % lower for abdomen/pelvis and chest/abdomen/pelvis scans, respectively, while in the chest the CBCT scan resulted in higher dose (23 %). Radiation dose from the CT component should be taken into consideration when evaluating total SPECT/CT patient dose.

  2. Assessment of CT dose to the fetus and pregnant female patient using patient-specific computational models.

    Science.gov (United States)

    Xie, Tianwu; Poletti, Pierre-Alexandre; Platon, Alexandra; Becker, Christoph D; Zaidi, Habib

    2017-09-08

    This work provides detailed estimates of the foetal dose from diagnostic CT imaging of pregnant patients to enable the assessment of the diagnostic benefits considering the associated radiation risks. To produce realistic biological and physical representations of pregnant patients and the embedded foetus, we developed a methodology for construction of patient-specific voxel-based computational phantoms based on existing standardised hybrid computational pregnant female phantoms. We estimated the maternal absorbed dose and foetal organ dose for 30 pregnant patients referred to the emergency unit of Geneva University Hospital for abdominal CT scans. The effective dose to the mother varied from 1.1 mSv to 2.0 mSv with an average of 1.6 mSv, while commercial dose-tracking software reported an average effective dose of 1.9 mSv (range 1.7-2.3 mSv). The foetal dose normalised to CTDIvol varies between 0.85 and 1.63 with an average of 1.17. The methodology for construction of personalised computational models can be exploited to estimate the patient-specific radiation dose from CT imaging procedures. Likewise, the dosimetric data can be used for assessment of the radiation risks to pregnant patients and the foetus from various CT scanning protocols, thus guiding the decision-making process. • In CT examinations, the absorbed dose is non-uniformly distributed within foetal organs. • This work reports, for the first time, estimates of foetal organ-level dose. • The foetal brain and skeleton doses present significant correlation with gestational age. • The conceptus dose normalised to CTDI vol varies between 0.85 and 1.63. • The developed methodology is adequate for patient-specific CT radiation dosimetry.

  3. Potential radionuclide emissions from stacks on the Hanford site, Part 1: Dose assessment

    Energy Technology Data Exchange (ETDEWEB)

    Davis, W.E.; Barnett, J.M. [Westinghouse Hanford Company, Richland, WA (United States)

    1995-02-01

    On February 3, 1993, the U.S. Department of Energy, Richland Operations Office received a Compliance Order and Information Request from the Director of the Air and Toxics Division of the U.S. Environmental Protection Agency, Region 10. The Compliance Order requires RL to evaluate all radionuclide emission points at the Hanford Site to determine which are subject to continuous emission monitoring requirements in 40 CFR 61, Subpart H, and to continuously monitor radionuclide emissions in accordance with requirements in 40 CFR 61.93. The Information Request required RL to provide a written Compliance Plan to meet the requirements of the Compliance Order. A Compliance Plan was submitted to EPA, Region 10, on April 30, 1993. The Compliance Plan specified that a dose assessment would be performed for 84 Westinghouse Hanford Company stacks registered with the Washington State Department of Health on the Hanford Site. Stacks that have the potential emissions to cause an effective dose equivalent to a maximum exposed individual greater than 0.1 mrem/y must be monitored continuously for radionuclide emissions. Five methods were approved by EPA, Region 10 for performing the assessments: Release Fractions from Appendix D of 40 CFR 61, Back Calculations Using A HEPA Filtration Factor, Nondestructive Assay of HEPA Filters, A Spill Release Fraction, and Upstream of HEPA Filter Air Concentrations. The first two methods were extremely conservative for estimating releases. The third method, which used a state-of-the-art portable gamma spectrometer, yielded surprising results from the distribution of radionuclides on the HEPA filters. All five methods are described. Assessments using a HEPA Filtration Factor for back calculations identified 32 stacks that would have emissions that would cause an EDE to the MEI greater than 0.1 mrem y{sup {minus}1}. The number was reduced to 15 stacks when the other methods were applied. The paper discusses reasons for the overestimates.

  4. CT outperforms radiographs at a comparable radiation dose in the assessment for spondylolysis

    Energy Technology Data Exchange (ETDEWEB)

    Fadell, Michael F.; Stewart, Jaime R.; Harned, Roger K.; Ingram, James D.; Miller, Angie L.; Strain, John D.; Weinman, Jason P. [Children' s Hospital Colorado, Department of Radiology, Aurora, CO (United States); University of Colorado Hospital, Department of Radiology, Aurora, CO (United States); Gralla, Jane [University of Colorado Denver, Department of Pediatrics, Aurora, CO (United States); Bercha, Istiaq [Children' s Hospital Colorado, Department of Radiology, Aurora, CO (United States)

    2015-07-15

    Lumbar spondylolysis, a unilateral or bilateral fracture at pars interarticularis, is a common cause of low back pain in children. The initial imaging study in the diagnosis of lumbar spondylolysis has historically been lumbar spine radiographs; however, radiographs can be equivocal or false-negative. Definitive diagnosis can be achieved with computed tomography (CT), but its use has been limited due to the dose of ionizing radiation to the patient. By limiting the z-axis coverage to the relevant anatomy and optimizing the CT protocol, we are able to provide a definitive diagnosis of fractures of the pars interarticularis at comparable or lower radiation dose than commonly performed lumbar spine radiographs. As there is no gold standard for the diagnosis of spondylolysis besides surgery, we compared interobserver agreement and degree of confidence to determine which modality is preferable. Sixty-two patients with low back pain ages 5-18 years were assessed for the presence of spondylolysis. Forty-seven patients were evaluated by radiography and 15 patients were evaluated by limited field-of-view CT. Both radiographic and CT examinations were assessed anonymously in random order for the presence or absence of spondylolysis by six raters. Agreement was assessed among raters using a Fleiss Kappa statistic for multiple raters. CT provided a significantly higher level of agreement among raters than radiographs (P < 0.001). The overall Kappa for rater agreement with radiographs was 0.24, 0.34 and 0.40 for 2, 3 or 4 views, respectively, and 0.88 with CT. Interobserver agreement is significantly greater using limited z-axis coverage CT when compared with radiographs. Radiologist confidence improved significantly with CT compared to radiographs regardless of the number of views. (orig.)

  5. Assessment of potential doses to workers during postulated accident conditions at the Waste Isolation Pilot Plant

    Energy Technology Data Exchange (ETDEWEB)

    Hoover, M.D.; Farrell, R.F. [DOE, Carlsbad, NM (United States); Newton, G.J.

    1995-12-01

    The recent 1995 WIPP Safety Analysis Report (SAR) Update provided detailed analyses of potential radiation doses to members of the public at the site boundary during postulated accident scenarios at the U.S. Department of Energy`s Waste Isolation Pilot Plant (WIPP). The SAR Update addressed the complete spectrum of potential accidents associated with handling and emplacing transuranic waste at WIPP, including damage to waste drums from fires, punctures, drops, and other disruptions. The report focused on the adequacy of the multiple layers of safety practice ({open_quotes}defense-in-depth{close_quotes}) at WIPP, which are designed to (1) reduce the likelihood of accidents and (2) limit the consequences of those accidents. The safeguards which contribute to defense-in-depth at WIPP include a substantial array of inherent design features, engineered controls, and administrative procedures. The SAR Update confirmed that the defense-in-depth at WIPP is adequate to assure the protection of the public and environment. As a supplement to the 1995 SAR Update, we have conducted additional analyses to confirm that these controls will also provide adequate protection to workers at the WIPP. The approaches and results of the worker dose assessment are summarized here. In conformance with the guidance of DOE Standard 3009-94, we emphasize that use of these evaluation guidelines is not intended to imply that these numbers constitute acceptable limits for worker exposures under accident conditions. However, in conjunction with the extensive safety assessment in the 1995 SAR Update, these results indicate that the Carlsbad Area Office strategy for the assessment of hazards and accidents assures the protection of workers, members of the public, and the environment.

  6. Quality assessment of delineation and dose planning of early breast cancer patients included in the randomized Skagen Trial 1

    DEFF Research Database (Denmark)

    Francolini, Giulio; Thomsen, Mette S; Yates, Esben S

    2017-01-01

    Background and purpose: To report on a Quality assessment (QA) of Skagen Trial 1, exploring hypofractionation for breast cancer patients with indication for regional nodal radiotherapy. Material and methods: Deviations from protocol regarding target volume delineations and dose parameters (Dmin, ...... coverage in most patients. Inter-observer variability in contouring was low. Dose parameters were in harmony with protocol regardless original or GS segmentation.......Background and purpose: To report on a Quality assessment (QA) of Skagen Trial 1, exploring hypofractionation for breast cancer patients with indication for regional nodal radiotherapy. Material and methods: Deviations from protocol regarding target volume delineations and dose parameters (Dmin......, Dmax, D98%, D95% and D2%) from randomly selected dose plans were assessed. Target volume delineation according to ESTRO guidelines was obtained through atlas based automated segmentation and centrally approved as gold standard (GS). Dice similarity scores (DSC) with original delineations were measured...

  7. Assessment of Mini-dose Succinylcholine Effect on Facilitating Laryngeal Mask Airway Insertion

    Directory of Open Access Journals (Sweden)

    Aghamohammadi Dawood

    2013-03-01

    Full Text Available Introduction: Laryngeal Mask Airway (LMA has gained wide acceptance for routine airway management and with increasing emphasis on day care surgery it is widely used. The aim of this study was to assess the effects of mini dose succinylcholine (0.1mg/kg with semi-inflated cuff on facilitation of laryngeal mask airway insertion in order to achieve more satisfaction yet less complications . Methods: In a randomized double-blinded study, sixty ASA 1, 2 and 3 patients aged 20-60 years scheduled for urologic surgical procedures were included. Thirty patients received succinylcholine (Group S, and thirty received 0.9% sodium choride as a placebo (Group C. Results: Coughing occured in 33.3% of patients in the control group and there was no incidence in succ group (P=0.002. Head or limb movement occurred in 70% of the patients in the control group vs. 10% in succ group (P<0.001. Laryngospasm occurred in 36.6 % of the patients in the control group but there was no incidence in succ group (P=0.004. Additional propofol was required in 53% of the patients in control group vs. 10% for succ group (P=0.001. Ease of insertion and first successfull attempt of LMA were achieved in 93.3% and 90% of the patients respectively in group S (P<0.05. Myalgia and sore throat occurred in 66.7 % of patients in the group C in comparison with 33.3% in group S (P=0.06. Conclusion: The combination of propofol with mini dose succinylcholine, provided a significantly better method for LMA insertion, while reduced propofol doses were needed and number of attempts decreased.

  8. MR cone-beam CT fusion image overlay for fluoroscopically guided percutaneous biopsies in pediatric patients.

    Science.gov (United States)

    Thakor, Avnesh S; Patel, Premal A; Gu, Richard; Rea, Vanessa; Amaral, Joao; Connolly, Bairbre L

    2016-03-01

    Lesions only visible on magnetic resonance (MR) imaging cannot easily be targeted for image-guided biopsy using ultrasound or X-rays but instead require MR guidance with MR-compatible needles and long procedure times (acquisition of multiple MR sequences). We developed an alternative method for performing these difficult biopsies in a standard interventional suite, by fusing MR with cone-beam CT images. The MR cone-beam CT fusion image is then used as an overlay to guide a biopsy needle to the target area under live fluoroscopic guidance. Advantages of this technique include (i) the ability for it to be performed in a conventional interventional suite, (ii) three-dimensional planning of the needle trajectory using cross-sectional imaging, (iii) real-time fluoroscopic guidance for needle trajectory correction and (iv) targeting within heterogeneous lesions based on MR signal characteristics to maximize the potential biopsy yield.

  9. Aid to Percutaneous Renal Access by Virtual Projection of the Ultrasound Puncture Tract onto Fluoroscopic Images

    CERN Document Server

    Mozer, Pierre; Leroy, Antoine; Baumann, Michael; Payan, Yohan; Troccaz, Jocelyne; Chartier-Kastler, Emmanuel; Richard, François

    2007-01-01

    Background and Purpose: Percutaneous renal access in the context of percutaneous nephrolithotomy (PCNL) is a difficult technique, requiring rapid and precise access to a particular calix. We present a computerized system designed to improve percutaneous renal access by projecting the ultrasound puncture tract onto fluoroscopic images. Materials and Methods: The system consists of a computer and a localizer allowing spatial localization of the position of the various instruments. Without any human intervention, the ultrasound nephrostomy tract is superimposed in real time onto fluoroscopic images acquired in various views. Results: We tested our approach by laboratory experiments on a phantom. Also, after approval by our institution's Ethics Committee, we validated this technique in the operating room during PCNL in one patient. Conclusion: Our system is reliable, and the absence of image-processing procedures makes it robust. We have initiated a prospective study to validate this technique both for PCNL speci...

  10. Foreign body extraction from soft tissue by using CT and fluoroscopic guidance: a new technique

    Energy Technology Data Exchange (ETDEWEB)

    Amoretti, Nicolas; Marcy, Pierre-Yves; Lesbats-Jacquot, Virginie; Fonquerne, Marie-Eve; Maratos, Yvonne [Centre Hospitalier Universitaire de Nice, Radiology Department, Nice (France); Hauger, Olivier [Hopital Pellegrin, Unite d' Imagerie Osteo-articulaire, CHU de Bordeaux (France); Hovorka, Istvan; Boileau, Pascal [Centre Hopitalier Universitaire de Nice, Orthopaedic Department, Nice (France)

    2010-01-15

    We report on a new minimally invasive technique for the retrieval of a surgical pin fragment after accidental migration into the soft tissue of the shoulder in two patients. The technique is performed under local anaesthesia and uses combined CT and fluoroscopic guidance. The materials used were simple, combining a bone biopsy needle and an endoscopy clamp. Pin displacement was confirmed under fluoroscopic guidance and the clamp was used to withdraw the pin to the cutaneous entry point under CT (step-by-step) guidance. The CT slices provide perfect visualisation of the vascular or nervous structures as well as perfect positioning of the extremity of the trocar relative to the material to be removed. This intervention avoids a second surgical intervention with a longer incision and avoided repeated general anaesthesia. (orig.)

  11. Use of a fluoroscopic overlay to assist arthroscopic anterior cruciate ligament reconstruction.

    Science.gov (United States)

    Moloney, Gele; Araujo, Paulo; Rabuck, Stephen; Carey, Robert; Rincon, Gustavo; Zhang, Xudong; Harner, Christopher

    2013-08-01

    A growing body of evidence supports the importance of anatomic tunnel positioning in the success of anterior cruciate ligament (ACL) reconstruction, which stimulates the need for technologies to aid surgeons in achieving accurate anatomic tunnel placement. Intraoperative fluoroscopy is potentially one such technology, while its efficacy and usability have yet to be established. To investigate the performance of an intraoperative fluoroscopic overlay in guiding tunnel placement during ACL reconstruction. Controlled laboratory study. Twenty cadaveric knees underwent computed tomography (CT) scans and arthroscopic digitization of ACL insertion sites. The outlines of the digitized insertion sites were mapped to the corresponding CT-acquired bone models through a co-registration procedure. Twenty orthopaedic surgeons performed simulated ACL reconstructions, each on a randomly assigned cadaveric knee, first without and then with the aid of a fluoroscopic overlay system. The overlay system displayed on a lateral fluoroscopic image targets points representing the locations of the ACL insertion sites estimated from the literature data. Surgeons were allowed to adjust their tunnel positions under the guidance of the fluoroscopic image. Their initial, intermediate, and final positions were documented and compared with the target points as well as the native insertion sites. Surgeons demonstrated significant (P < .01) improvements in femoral and tibial tunnel placements relative to the target points from an average distance of 3.9 mm to 1.6 mm on the femur and 2.1 mm to 0.9 mm on the tibia. The improvements toward the knee-specific actual insertion sites were significant on the tibial side but not on the femoral side. Surgeons can be successfully guided with fluoroscopy to create more consistent femoral and tibial tunnels during ACL reconstruction. More research is warranted to develop better population representations of the locations of natural insertion sites

  12. R&D of the Fluoroscopes of 100 MeV Cyclotron Beam Lines

    Institute of Scientific and Technical Information of China (English)

    YIN; Meng; GUAN; Feng-ping; XIE; Huai-dong; ZHENG; Xia; XING; Jian-sheng; LV; Yin-long

    2013-01-01

    Beijing Radioactive Ion-beam Facility(BRIF)consists of a 100 MeV H-cyclotron CYCIAE-100and nine beam lines.All the beam lines provide the channels of the proton beam or the neutron beam to the terminal of physics experiment.There are many beam diagnosis monitors distributing along the beam lines,including,Faraday cups,beam position monitors,fluoroscopes,collimators,emittance measurement

  13. Correction of malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Ryong; Baek, Kyong Hee; Jung, Gyoo Sik; Huh, Jin Do; Joh, Young Duk; Rim, Hark [Kosin Medical College, Pusan (Korea, Republic of)

    1997-11-01

    To determine the efficacy of correction of a malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance. Between November 1994 and March 1997, we performed 15 manipulations in 12 patients in whom a dual-cuff, straight Tenckhoff peritoneal dialysis catheter had been implanted due to chronic renal failure. The causes of catheter malfunctioning were inadequate drainage of the dialysate(n=14) and painful dialysis(n=1). Under fluoroscopic guidance, adhesiolysis and repositioning of the malfunctioning catheter were performed with an Amplatz Super Stiff guidewire and the stiffener from a biliary drainage catheter. The results of procedures were categorized as either immediate or durable success, this latter being defined as adequate catheter function for at least one month after the procedure. Immediate success was achieved in 14 of 15 procedures (93%), and durable success in 7 of 15(47%). The mean duration of catheter function was 157 (range, 30 to 578) days. After manipulation, abdominal pain developed in eight patients and peritonitis in two, but with conservative treatment, these symptoms improved. The correction of a malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance is an effective means of restoring catheter function and may be an effective alternative to surgical reimplantation of the catheter, or hemodialysis.

  14. Percutaneous Drainage of Postoperative Pelvic Abscess: Fluoroscopic and US-Guided Transgluteal Approach

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Hyo Jin; Hong, Hyun Pyo; Lee, Hyung Geun; Choi, Yoon Jung; Lee, Young Rae; Lee, Ji Young; Park, Hae Won [Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, Sam Soo [Kangwon National University College of Medicine, Chuncheon (Korea, Republic of)

    2010-08-15

    To retrospectively review the effectiveness and safety of fluoroscopic and US-guided percutaneous transgluteal drainage of postoperative pelvic abscesses. From January 2002 to December 2007, 594 patients underwent surgery at our institution due to rectosigmoid cancer. A retrospective analysis revealed that percutaneous drainage of a postoperative pelvic abscess was performed in 19 out of the 594 patients (3.19%) that underwent surgery (13 male, 6 female; mean age, 57.9 years; age range, 40-82 years). The transgluteal and other methods were used for percutaneous drainage and the success rate, duration of therapy, and complication rate were evaluated. The transgluteal approach was performed with fluoroscopic and US-guidance in 10 patients (52.6%). A catheter was inserted through a preexisting surgical drain in 5 patients (26.3%). The transabdominal approach was performed under US-guidance in 4 patients (21.0%). Technical success was achieved in all patients. The catheter was removed after a mean of 14 days. In 2 patients, who were treated by the transgluteal approach, subsequent surgery was performed due to incomplete resolution of the abscess (10.5%). The mean duration of catheter drainage using the transgluteal approach (16.5 days) was longer than other methods (11.2 days). Furthermore, no procedure-related major complications or mortality was observed in all methods. The percutaneous transgluteal approach to a postoperative pelvic abscess with US and fluoroscopic guidance is relatively safe and effective.

  15. Transthoracic fine needle aspiration biopsy of subcarinal lesion: oblique approach using biplane fluoroscopic guidance

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Tae; Jeon, Seok Chol; Choi, Yo Won; Seo, Heung Suk; Hahm, Chang Kok [School of Medicine, Hanyang University, Seoul (Korea, Republic of)

    1995-09-15

    To evaluate effectiveness of oblique approach under biplane fluoroscopic guidance in transthoracic fine needle aspiration biopsy. Fourteen consecutive patients underwent transthoracic fine needle aspiration biopsy for subcarinal lesions. Subcarina was the only accessible biopsy site in 13 patients. Subcarinal biopsy was performed to determine the presence of metastasis in an enlarged subcarinal lymph node in the remaining one patient. Before biopsy, we evaluated the size and location of the lesion on preliminary plain chest X-ray film and CT scan. Under dual projection fluoroscopic guidance, biopsy was performed through right posterior intercostal space with the patient prone by using oblique approach. On 15 degree LAO projection the needle was directed to the area anterior to the spine and advanced to the line extending through the posterior wall of the main bronchus. Cytologic diagnosis was made in 12 out of 14 patients(accuracy 85.7%). The final diagnosis consisted of 5 squamous cell carcinoma, 5 small cell carcinoma, 1 adenocarcinoma and 1 adenosquamous carcinoma. Pneumothorax developed in 2 patients(14%) and was managed by chest tube drainage. Mild hemoptysis was observed in 2. Transthoracic fine needle aspiration biopsy using oblique approach under biplane fluoroscopic guidance is a relatively safe and sensitive method for the histologic diagnosis of subcarinal lesion.

  16. EcoDoses. Improving radiological assessment of doses to man from terrestrial ecosystems. A status report for the NKS-B project 2004

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Sven P.; Isaksson, M.; Nilsson, Elisabeth (and others)

    2005-07-01

    The NKS B-programme EcoDoses project started in 2003 as a collaboration between all the Nordic countries. The aim of the project is to improve the radiological assessments of doses to man from terrestrial ecosystems. The present report sums up the work performed in the second phase of the project. The main topics in 2004 have been: (i) A continuation of previous work with a better approach for estimating global fallout on a regional or national scale, based on a correlation between precipitation and deposition rates. (ii) Fur-ther extension of the EcoDoses milk database. Estimation of effective ecological half lives of {sup 137}Cs in cows milk focussing on suitable post-Chernobyl time-series. Modelling integrated transfer of {sup 13}7{sup C}s to cow's milk from Nordic countries. (iii) Determination of effective ecological half lives for fresh water fish from Nordic lakes. (iv) Investigate ra-dioecological sensitivity for Nordic populations. (v) Food-chain modelling using the Eco-sys-model, which is the underlying food- and dose-module in several computerised deci-sion-making systems. (au)

  17. EcoDoses improving radiological assessment of doses to man from terrestrial ecosystems. A status report for the NKS-B project 2003

    Energy Technology Data Exchange (ETDEWEB)

    Bergan, T. [Lavrans Skuterud, Haevard Thoerring (Norway); Liland, A. [Norwegian Radiation Protection Authority (NRPA) (Denmark)] (eds.)

    2004-05-01

    The NKS B-programme EcoDoses project started in 2003 as a collaboration between all the Nordic countries. The aim of the project is to improve the radiological assessments of doses to man from terrestrial ecosystems. The first part, conducted in 2003, has focussed on an extensive collation and review of both published and unpublished data from all the Nordic countries for the nuclear weapons fallout period and the post-Chemobyl period. This included data on radionuclides in air filters, precipitation, soil samples, milk and reindeer. Based on this, an improved model for estimating radioactive fallout based on precipitation data during the nuclear weapons fallout period has been developed. Effective ecological half- lives for 137Cs and 90Sr in milk have been calculated for the nuclear weapons fallout period. For reindeer the ecological half- lives for 137Cs have been calculated for both the nuclear weapons fallout period and the post-Chemobyl period. The data were also used to compare modelling results with observed concentrations. This was done at a workshop where the radioecological food-and-dose module in the ARGOS decision support system was used to predict transfer of deposited radionuclides to foodstuffs and subsequent radiation doses to man. The work conducted the first year is presented in this report and gives interesting, new results relevant for terrestrial radioecology. (au)

  18. Transcutaneous aortic valve replacement with the Edwards SAPIEN XT and Medtronic CoreValve prosthesis under fluoroscopic guidance and local anaesthesia only.

    Science.gov (United States)

    Greif, Martin; Lange, Philipp; Näbauer, Michael; Schwarz, Florian; Becker, Christoph; Schmitz, Christoph; Pohl, Tilmann; D'Anastasi, Melvin; Boekstegers, Peter; Massberg, Steffen; Kupatt, Christian

    2014-05-01

    To assess the feasibility of transcatheter aortic valve implantation (TAVI; Medtronic CoreValve and Edwards SAPIEN XT) under local anaesthesia with only mild analgesic medication and fluoroscopic guidance. 461 patients underwent TAVI under local anaesthesia with lidocaine. The procedure was performed successfully in 459 of the cases. All patients were also treated with piritramide, metoclopramide hydrochloride and 62 mg dimenhydrinate. Monitoring consisted of a six-electrode, virtual 12-lead ECG, pulse oximetry, and invasive arterial pressure measurement. There was no continuous surveillance by an anaesthesiologist. There was no need for conversion to general anaesthesia except in four patients who required cardiopulmonary resuscitation. Conscious sedation with intravenous administration of midazolam for agitation or inotropic medication for prolonged hypotension was necessary in only seven of the 461 patients. The combined safety end point according to the Valve Academic Research Consortium consensus document was reached in 12.6%. Our results show that TAVI performed under local anaesthesia with only mild analgesic medication and under fluoroscopic guidance is feasible, with good outcome comparable to published data.

  19. Detection of respiratory motion in fluoroscopic images for adaptive radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Moser, T; Nill, S; Remmert, G; Bendl, R [German Cancer Research Center, Heidelberg (Germany); Biederer, J [Department of Diagnostic Radiology, University Hospital Schleswig-Holstein, Kiel (Germany)], E-mail: T.Moser@dkfz-heidelberg.de

    2008-06-21

    Respiratory motion limits the potential of modern high-precision radiotherapy techniques such as IMRT and particle therapy. Due to the uncertainty of tumour localization, the ability of achieving dose conformation often cannot be exploited sufficiently, especially in the case of lung tumours. Various methods have been proposed to track the position of tumours using external signals, e.g. with the help of a respiratory belt or by observing external markers. Retrospectively gated time-resolved x-ray computed tomography (4D CT) studies prior to therapy can be used to register the external signals with the tumour motion. However, during treatment the actual motion of internal structures may be different. Direct control of tissue motion by online imaging during treatment promises more precise information. On the other hand, it is more complex, since a larger amount of data must be processed in order to determine the motion. Three major questions arise from this issue. Firstly, can the motion that has occurred be precisely determined in the images? Secondly, how large must, respectively how small can, the observed region be chosen to get a reliable signal? Finally, is it possible to predict the proximate tumour location within sufficiently short acquisition times to make this information available for gating irradiation? Based on multiple studies on a porcine lung phantom, we have tried to examine these questions carefully. We found a basic characteristic of the breathing cycle in images using the image similarity method normalized mutual information. Moreover, we examined the performance of the calculations and proposed an image-based gating technique. In this paper, we present the results and validation performed with a real patient data set. This allows for the conclusion that it is possible to build up a gating system based on image data, solely, or (at least in avoidance of an exceeding exposure dose) to verify gates proposed by the various external systems.

  20. Transverse morphology of the sacroiliac joint: effect of angulation and implications for fluoroscopically guided sacroiliac joint injection

    Energy Technology Data Exchange (ETDEWEB)

    Ling, B.C.; Lee, J.W.; Man, H.S.J.; Grace, M.G.A.; Lambert, R.G.W. [Department of Radiology and Diagnostic Imaging, University of Alberta Hospital, Edmonton (Canada); Jhangri, G.S. [Department of Public Health Sciences, University of Alberta Hospital, Edmonton (Canada)

    2006-11-15

    Effects of angulation of computed tomography (CT) reconstruction plane on sacroiliac (SI) joint morphology were studied, and factors influencing the approach to fluoroscopically guided SI joint injection were assessed. CT scans of pelvises were reformatted on 41 subjects, aged 51.7 ({+-}15.1) years. Transverse images were reconstructed at the caudal 3 cm of the SI joint tilting plane of reconstruction from -30 to +30 at 15 increments. Anteroposterior diameter of joint (depth), angle from sagittal plane (orientation angle), and distance from skin were measured. Joint contour was classified, and presence of bone blocking access to the joint was recorded. Comparison between angles were analysed by t-test. Relationships between variables were assessed by a Pearson correlation test. Depth was shorter with angulation in the inferior direction (P<0.01). Orientation angle increased with superior angulation (P<0.01). Distance from skin increased (P<0.01) with angulation in either direction. Joint contour was significantly different from baseline at each angle (P<0.001) but highly variable. Inferior angulation resulted in interposition of ilium between skin and SI joint, and superior angulation caused bone block due to the lower sacrum. None of these features was identified without tilting of the reconstruction plane, and effects were more pronounced with steeper angulation.

  1. Study of the radiation dose reduction capability of a CT reconstruction algorithm: LCD performance assessment using mathematical model observers

    Science.gov (United States)

    Fan, Jiahua; Tseng, Hsin-Wu; Kupinski, Matthew; Cao, Guangzhi; Sainath, Paavana; Hsieh, Jiang

    2013-03-01

    Radiation dose on patient has become a major concern today for Computed Tomography (CT) imaging in clinical practice. Various hardware and algorithm solutions have been designed to reduce dose. Among them, iterative reconstruction (IR) has been widely expected to be an effective dose reduction approach for CT. However, there is no clear understanding on the exact amount of dose saving an IR approach can offer for various clinical applications. We know that quantitative image quality assessment should be task-based. This work applied mathematical model observers to study detectability performance of CT scan data reconstructed using an advanced IR approach as well as the conventional filtered back-projection (FBP) approach. The purpose of this work is to establish a practical and robust approach for CT IR detectability image quality evaluation and to assess the dose saving capability of the IR method under study. Low contrast (LC) objects imbedded in head size and body size phantoms were imaged multiple times with different dose levels. Independent signal present and absent pairs were generated for model observer study training and testing. Receiver Operating Characteristic (ROC) curves for location known exact and location ROC (LROC) curves for location unknown as well as their corresponding the area under the curve (AUC) values were calculated. Results showed approximately 3 times dose reduction has been achieved using the IR method under study.

  2. Assessment of the absorbed dose to organs from bone mineral density scan by using TLDS and the Monte Carlo method

    Directory of Open Access Journals (Sweden)

    Karimian Alireza

    2014-01-01

    Full Text Available Nowadays, dual energy X-ray absorptiometry is used in bone mineral density systems to assess the amount of osteoporosis. The purpose of this research is to evaluate patient organ doses from dual X-ray absorptiometry by thermoluminescence dosimeters chips and Monte Carlo method. To achieve this goal, in the first step, the surface dose of the cervix, kidney, abdomen region, and thyroid were measured by using TLD-GR 200 at various organ locations. Then, to evaluate the absorbed dose by simulation, the BMD system, patient's body, X-ray source and radiosensitive tissues were simulated by the Monte Carlo method. The results showed, for the spine (left femur bone mineral density scan by using thermoluminescence dosimeters, the absorbed doses of the cervix and kidney were 4.5 (5.64 and 162.17 (3.99(mGy, respectively. For spine (left femur bone mineral density scan in simulation, the absorbed doses of the cervix and kidney were 4.19 (5.88 and 175 (3.68(mGy, respectively. The data obtained showed that the absorbed dose of the kidney in the spine scan is noticeable. Furthermore, because of the small relative difference between the simulation and experimental results, the radiation absorbed dose may be assessed by simulation and software, especially for internal organs, and at different depths of otherwise inaccessible organs which is not possible in experiments.

  3. Comparison of fluoro and cine coronary angiography: balancing acceptable outcomes with a reduction in radiation dose.

    Science.gov (United States)

    Olcay, Ayhan; Guler, Ekrem; Karaca, Ibrahim Oguz; Omaygenc, Mehmet Onur; Kizilirmak, Filiz; Olgun, Erkam; Yenipinar, Esra; Cakmak, Huseyin Altug; Duman, Dursun

    2015-04-01

    Use of last fluoro hold (LFH) mode in fluoroscopy, which enables the last live image to be saved and displayed, could reduce radiation during percutaneous coronary intervention when compared with cine mode. No previous study compared coronary angiography radiation doses and image quality between LFH and conventional cine mode techniques. We compared cumulative dose-area product (DAP), cumulative air kerma, fluoroscopy time, contrast use, interobserver variability of visual assessment between LFH angiography, and conventional cine angiography techniques. Forty-six patients were prospectively enrolled into the LFH group and 82 patients into the cine angiography group according to operator decision. Mean cumulative DAP was higher in the cine group vs the LFH group (50058.98 ± 53542.71 mGy•cm² vs 11349.2 ± 8796.46 mGy•cm²; Pcine group vs the LFH group (3.87 ± 5.08 minutes vs 1.66 ± 1.51 minutes; Pcine group vs the LFH group (112.07 ± 43.79 cc vs 88.15 ± 23.84 cc; Pcine and LFH angiography groups (0.66680 ± 0.19309 vs 0.54193 ± 0.31046; P=.20). Radiation doses, contrast use, and fluoroscopy times are lower in fluoroscopic LFH angiography vs cine angiography. Interclass variability of visual stenosis estimation between three operators was not different between cine and LFH groups. Fluoroscopic LFH images conventionally have inferior diagnostic quality when compared with cine coronary angiography, but with new angiographic systems with improved LFH image quality, these images may be adequate for diagnostic coronary angiography.

  4. Assessment of fetal radiation dose to patients and staff in diagnostic radiology

    Energy Technology Data Exchange (ETDEWEB)

    Osei, E.K

    2000-07-01

    A major source of uncertainty in the estimation of fetal absorbed radiation dose is the influence of fetal size and position as these change with gestational age. Consequently, dose to the fetus is related to gestational age. Most studies of fetal dose estimation during pregnancy assume that the uterus dose is equal to fetal dose. These dose estimates do not take account of gestational age and individual fetal depth, factors which are significant when calculating dose. To establish both positional and size data for estimation of fetal absorbed dose from radiological examinations, the depths from the mother's anterior surface to the mid-line of the fetal head and abdomen were measured from ultrasound scans in 215 pregnant women. Depths were measured along a ray path projected in the anterior-posterior direction from the mother's abdomen. The fetal size was estimated from measurements of the fetal abdominal and head circumference, femur length and the biparietal diameter. The effects of fetal presentation, maternal bladder volume, placenta location, gestational age and maternal AP thickness on fetal depth and size were analysed. A Monte Carlo (MC) model was developed, and used to derive factors for converting dose-area product and free-in-air entrance surface dose from medical exposure of a pregnant patient to absorbed dose to the uterus/embryo, and for converting uterus dose to fetal dose in the later stages of pregnancy. Also presented are factors for converting thermoluminescence dosimeter reading from occupational exposure of a pregnant worker to equivalent dose to the fetus. The MC model was verified experimentally by direct measurement of uterus depth dose in a female Rando phantom, and also by comparison with other experimental work and MC results in the literature. The application of the various conversion factors is demonstrated by a review of the dose estimation process in 50 cases of fetal irradiation from medical exposures. (author)

  5. Assessment of low-dose radiotoxicity in microorganisms and higher organisms

    Energy Technology Data Exchange (ETDEWEB)

    Obeid, Muhammad Hassan

    2016-01-11

    This work was dedicated to quantify and distinguish the radio- and chemitoxic effects of environmentally relevant low doses of uranium on the metabolism of microorganisms and multicellular organisms by a modern and highly sensitive microcalorimetry. In such low-dose regime, lethality is low or absent. Therefore, quantitative assays based on survival curves cannot be employed, particularly for multicellular organisms. Even in the case of microbial growth, where individual cells may be killed by particle radiation, classical toxicity assessments based on colony counting are not only extremely time-consuming but also highly error-prone. Therefore, measuring the metabolic activity of the organism under such kinds of conditions would give an extremely valuable quantitative measure of viability that is based on life cell monitoring, rather than determining lethality at higher doses and extrapolating it to the low dose regime. The basic concept is simple as it relies on the metabolic heat produced by an organism during development, growth or replication as an inevitable byproduct of all biochemical processes. A metabolic effect in this concept is defined as a change in heat production over time in the presence of a stressor, such as a heavy metal. This approach appeared to be particular versatile for the low dose regime. Thus, the thesis attempted in this case to measure the enthalpy production of a bacterial population as a whole to derive novel toxicity concepts. In the following chapters, an introduction about the properties of ionizing radiation will be briefly presented, in addition to a review about the isothermal calorimetry and its application in studying the bacterial growth. Later in chapter 2, the effect of uranium on the metabolic activity of three different bacterial strains isolated form a uranium mining waste pile together with a reference strain that is genetically related to them will be investigated. Due to the lack of published dedicated calibration

  6. Assessment of a low dose of IV midazolam used orally for conscious sedation in pediatric dentistry

    Directory of Open Access Journals (Sweden)

    M Mortazavi

    2009-08-01

    Full Text Available Background and the purpose of the study: Midazolam is preferably used in pediatric dentistry for quick onset of action and recovery. The aim of this prospective, observer-blind and placebo-controlled study was to assess the efficacy of a low dose of oral midazolam in modification of  the behavior of young pediatric dental patients. Methods: Forty children aged 3 to 5 years who displayed ratings 1 or 2 on the Frankl Scale and  were healthy by the American Society of Anesthesiologists-I status were randomly divided into two experimental and control groups of 20 each. All children required pulpotomy and restoration of D and E teeth and received either 0.25mg/kg of a 15mg/3ml IV midazolam mixed in black cherry syrup or the syrup alone. Subjects were continuously observed and monitored with pulse oximetry. Houpt's Behavioral Ratings was used to determine the overall behavior, the degree of crying and movement during treatment. Mann-Whitney U test was used for statistical analysis. Results and major conclusion: Patients who received 0.25mg/kg of the prepared oral midazolam significantly behaved better during treatment than the placebo controls (P<0.05. In comparison with the placebo group, reduced movement and crying were observed in the midazolam group (P<0.05. No adverse effects were observed and treatments were completed successfully. A low dose of 0.25mg/kg of a 15mg/3ml IV midazolam mixed in black cherry syrup was found to be effective in conscious sedation of young pediatric dental patients.

  7. Web-based training course for evaluating radiological dose assessment in NRC's license termination process.

    Science.gov (United States)

    Lepoire, D; Richmond, P; Cheng, J-J; Kamboj, S; Arnish, J; Chen, S Y; Barr, C; McKenney, C

    2008-08-01

    As part of the requirement for terminating the licenses of nuclear power plants or other nuclear facilities, license termination plans or decommissioning plans are submitted by the licensee to the U.S. Nuclear Regulatory Commission (NRC) for review and approval. Decommissioning plans generally refer to the decommissioning of nonreactor facilities, while license termination plans specifically refer to the decommissioning of nuclear reactor facilities. To provide a uniform and consistent review of dose modeling aspects of these plans and to address NRC-wide knowledge management issues, the NRC, in 2006, commissioned Argonne National Laboratory to develop a Web-based training course on reviewing radiological dose assessments for license termination. The course, which had first been developed in 2005 to target specific aspects of the review processes for license termination plans and decommissioning plans, evolved from a live classroom course into a Web-based training course in 2006. The objective of the Web-based training course is to train NRC staff members (who have various relevant job functions and are located at headquarters, regional offices, and site locations) to conduct an effective review of dose modeling in accordance with the latest NRC guidance, including NUREG-1757, Volumes 1 and 2. The exact size of the staff population who will receive the training has not yet been accurately determined but will depend on various factors such as the decommissioning activities at the NRC. This Web-based training course is designed to give NRC staff members modern, flexible access to training. To this end, the course is divided into 16 modules: 9 core modules that deal with basic topics, and 7 advanced modules that deal with complex issues or job-specific topics. The core and advanced modules are tailored to various NRC staff members with different job functions. The Web-based system uses the commercially available software Articulate, which incorporates audio, video

  8. Revised series of stylized anthropometric phantoms for internal and external radiation dose assessment

    Science.gov (United States)

    Han, Eunyoung

    At present, the dosimetry systems of both the International Commission on Radiological Protection, and the Society of Nuclear Medicine's Medical Internal Radiation Dose Committee utilize a series of stylized or mathematical anthropometric models of patient anatomy developed in 1987 at the Oak Ridge National Laboratory (ORNL). In this study, substantial revisions to the ORNL phantom series are reported with tissue compositions, tissue densities, and organ masses adjusted to match their most recent values in the literature. In addition, both the ICRP and MIRD systems of internal dosimetry implicitly consider that electron and beta-particle energy emitted within the source organs of the patient are fully deposited within these organs. With the development of the revised ORNL phantom series, three additional applications were explored as part of this dissertation research. First, the phantoms were used in combination to assess external radiation exposures to family members caring or interacting with patients released from the hospital following radionuclide therapy with I-131. Values of family member effective dose are then compared to values obtained using NRC guidance and based on a simple point-source methodology which ignores the effects of photon attenuation and scatter within both the source individual (patient) and the target individual (family member). Second, the anatomical structures of the extrathoracic airways and thoracic airways (exclusive of the lungs themselves) have been included in the entire revised ORNL phantom series of pediatric individuals. Values of cross-region photon dose are explored for use in radioactive aerosol inhalation exposures to members of the general public, and comparisons are made to values given by the ICRP in which surrogate organ assignments were made in the absence of explicit models of these airways. Finally, the revised ORNL phantoms of the adult male and adult female are used to determine internal photon exposures to

  9. Development and validation of a questionnaire to assess carbohydrate and insulin-dosing knowledge in youth with type 1 diabetes.

    Science.gov (United States)

    Koontz, Michaela B; Cuttler, Leona; Palmert, Mark R; O'Riordan, Maryann; Borawski, Elaine A; McConnell, Judy; Kern, Elizabeth O

    2010-03-01

    OBJECTIVE The American Diabetes Association advocates insulin regimens for youth with type 1 diabetes that involve adjusting insulin dose based on carbohydrate intake and blood glucose level. Implementing these regimens requires knowledge about carbohydrate content of foods and subsequent calculations of insulin dose, skills that may be difficult to gauge in practice. Therefore, we sought to develop and validate a questionnaire, the PedCarbQuiz (PCQ), to assess carbohydrate and insulin-dosing knowledge in youth with type 1 diabetes. RESEARCH DESIGN AND METHODS After development by an expert panel, the PCQ was administered to 75 youth with type 1 diabetes or their parents. Reliability was assessed by Cronbach alpha and split-half testing. To assess validity, scores were correlated with A1C, expert assessments, parent educational level, and complexity of insulin regimen. RESULTS PCQ mean score was 87 +/- 9.7% (range 42-98%). Cronbach alpha was 0.88, and correlation of split halves was 0.59 (P PCQ scores correlated significantly with lower A1C (r = -0.29, P = 0.01) and expert assessments (r = 0.56, P PCQ is a novel, easily administered instrument to assess knowledge about carbohydrates and insulin dosing calculations. Initial analyses support the reliability and validity of the PCQ.

  10. A method for independent modelling in support of regulatory review of dose assessments.

    Science.gov (United States)

    Dverstorp, Björn; Xu, Shulan

    2017-03-22

    Several countries consider geological disposal facilities as the preferred option for spent nuclear fuel due to their potential to provide isolation from the surface environment on very long timescales. In 2011 the Swedish Nuclear Fuel & Waste Management Co. (SKB) submitted a license application for construction of a spent nuclear fuel repository. The disposal method involves disposing spent fuel in copper canisters with a cast iron insert at about 500 m depth in crystalline basement rock, and each canister is surrounded by a buffer of swelling bentonite clay. SKB's license application is supported by a post-closure safety assessment, SR-Site. SR-Site has been reviewed by the Swedish Radiation Safety Authority (SSM) for five years. The main method for review of SKB's license application is document review, which is carried out by SSM's staff and supported by SSM's external experts. The review has proven a challenging task due to its broad scope, complexity and multidisciplinary nature. SSM and its predecessors have, for several decades, been developing independent models to support regulatory reviews of post-closure safety assessments for geological repositories. For the review of SR-Site, SSM has developed a modelling approach with a structured application of independent modelling activities, including replication modelling, use of alternative conceptual models and bounding calculations, to complement the traditional document review. This paper describes this scheme and its application to biosphere and dose assessment modelling. SSM's independent modelling has provided important insights regarding quality and reasonableness of SKB's rather complex biosphere modelling and has helped quantifying conservatisms and highlighting conceptual uncertainty. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Scoping assessment of radiological doses to aquatic organisms and wildlife -- N Springs

    Energy Technology Data Exchange (ETDEWEB)

    Poston, T.M.; Soldat, J.K.

    1992-10-01

    Estimated does rates were determined for endemic biota inhabiting the N Springs area based primarily on spring water data collected from the first 6 months of 1991. Radiological dose estimates were computed from measured values of specific radionuclides and modeled levels of radionuclides using established computer codes. The highest doses were predicted in hypothetical populations of clams, fish-eating ducks, and rabbits. The calculated dose estimates did not exceed 1 rad/d, an administrative dose rate established by the US Department of Energy for the protection of native aquatic biota. An administrative dose rate has not been established for terrestrial wildlife.

  12. Scoping assessment of radiological doses to aquatic organisms and wildlife -- N Springs. [N Springs

    Energy Technology Data Exchange (ETDEWEB)

    Poston, T.M.; Soldat, J.K.

    1992-10-01

    Estimated does rates were determined for endemic biota inhabiting the N Springs area based primarily on spring water data collected from the first 6 months of 1991. Radiological dose estimates were computed from measured values of specific radionuclides and modeled levels of radionuclides using established computer codes. The highest doses were predicted in hypothetical populations of clams, fish-eating ducks, and rabbits. The calculated dose estimates did not exceed 1 rad/d, an administrative dose rate established by the US Department of Energy for the protection of native aquatic biota. An administrative dose rate has not been established for terrestrial wildlife.

  13. Assessing doses to terrestrial wildlife at a radioactive waste disposal site: Inter-comparison of modelling approaches

    Energy Technology Data Exchange (ETDEWEB)

    Johansen, M.P., E-mail: mathew.johansen@ansto.gov.au [Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232 (Australia); Barnett, C.L., E-mail: clb@ceh.ac.uk [Centre for Ecology and Hydrology, Lancaster (United Kingdom); Beresford, N.A., E-mail: nab@ceh.ac.uk [Centre for Ecology and Hydrology, Lancaster (United Kingdom); Brown, J.E., E-mail: justin.brown@nrpa.no [Norwegian Radiation Protection Authority, Oesteraas (Norway); Cerne, M., E-mail: marko.cerne@ijs.si [Jozef Stefan Institute, Ljubljana (Slovenia); Howard, B.J., E-mail: bjho@ceh.ac.uk [Centre for Ecology and Hydrology, Lancaster (United Kingdom); Kamboj, S., E-mail: skamboj@anl.gov [Argonne National Laboratory, IL (United States); Keum, D.-K., E-mail: dkkeum@kaeri.re.kr [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Smodis, B. [Jozef Stefan Institute, Ljubljana (Slovenia); Twining, J.R., E-mail: jrt@ansto.gov.au [Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232 (Australia); Vandenhove, H., E-mail: hvandenh@sckcen.be [Belgian Nuclear Research Centre, Mol (Belgium); Vives i Batlle, J., E-mail: jvbatll@sckcen.be [Belgian Nuclear Research Centre, Mol (Belgium); Wood, M.D., E-mail: m.d.wood@salford.ac.uk [University of Salford, Manchester (United Kingdom); Yu, C., E-mail: cyu@anl.gov [Argonne National Laboratory, IL (United States)

    2012-06-15

    Radiological doses to terrestrial wildlife were examined in this model inter-comparison study that emphasised factors causing variability in dose estimation. The study participants used varying modelling approaches and information sources to estimate dose rates and tissue concentrations for a range of biota types exposed to soil contamination at a shallow radionuclide waste burial site in Australia. Results indicated that the dominant factor causing variation in dose rate estimates (up to three orders of magnitude on mean total dose rates) was the soil-to-organism transfer of radionuclides that included variation in transfer parameter values as well as transfer calculation methods. Additional variation was associated with other modelling factors including: how participants conceptualised and modelled the exposure configurations (two orders of magnitude); which progeny to include with the parent radionuclide (typically less than one order of magnitude); and dose calculation parameters, including radiation weighting factors and dose conversion coefficients (typically less than one order of magnitude). Probabilistic approaches to model parameterisation were used to encompass and describe variable model parameters and outcomes. The study confirms the need for continued evaluation of the underlying mechanisms governing soil-to-organism transfer of radionuclides to improve estimation of dose rates to terrestrial wildlife. The exposure pathways and configurations available in most current codes are limited when considering instances where organisms access subsurface contamination through rooting, burrowing, or using different localised waste areas as part of their habitual routines. - Highlights: Black-Right-Pointing-Pointer Assessment of modelled dose rates to terrestrial biota from radionuclides. Black-Right-Pointing-Pointer The substantial variation among current approaches is quantifiable. Black-Right-Pointing-Pointer The dominant variable was soil

  14. EXPOSURE DOSES ASSESSMENT OF POPULATION AT LONG-TERM PERIOD AFTER THE CHERNOBYL ACCIDENT: INTERNATIONAL COLLABORATION EXPERIENCE

    Directory of Open Access Journals (Sweden)

    N. G. Vlasova

    2013-01-01

    Full Text Available The study which had been conducted in the period from 1990 to 2000’s in the settlements ofGomelregion showed that the average internal exposure doses of population living in the settlements situated on territories with equal levels of contamination density were considerably different. The reasons for the difference have been revealed. It was shown that not only radiation contamination of territory but also a range of factors of non-radiation origin have influence on formation of internal exposure dose. The hypothesis has been approved that internal exposure dose of each individual and also of each family has its certain place, constant in time at a dose distribution curve. This appropriateness had been used as a methodological basis for reconstruction of subjects’ individual doses for any time period. Method for estimating the average annual effective exposure doses of inhabitants living in contaminated settlements of theBelarusRepublichad been developed. The results of the Whole Body Counter measurements had been used for direct assessment of internal exposure dose and as the basis for developing a model. Model for the dose estimation is based on the classification of settlements according to regional characteristics of soil, which cause 137Cs in taking with locally produced foodstuff. The model is also based on regression of daily 137Cs intake on the density contamination of the soil for each region. The effect of the indirect factors on the dose forming had been taken into account: the number of inhabitants and the area of forest around the settlement. According to the developed method, there had been created a Catalog of Average Annual Effective Doses of Residents of the Belarus Republic.

  15. Biosphere modelling for dose assessments of radioactive waste repositories. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Klos, R. [Paul Scherrer Inst., Wuerenlingen (Switzerland)] [and others

    1996-09-01

    The aims of the Complementary Studies Working Group were: to investigate and explain differences which exist between contemporary models with respect to how, for a given test case, they represent the modelled Features, Events and Processes (FEPs) and how the nature of these representations affects the calculational end-points; to determine the most appropriate ways of representing key FEPs; to identify where knowledge needs to be improved to give better representations of these key FEPs in the future and where simplifications of existing formulations might be possible; to show that the modelling undertaken is suitable for purpose, in that it is robust and that it is unlikely that the radiological consequences calculated by the models would be underestimated (so that any conservative bias in the models is justified); to build confidence in the available modelling tools; to extend the work undertaken in the first phase of BIOMOVS to include consideration of radiological dose. Ten modelling groups from Western Europe and Canada have participated, revealing a variety of representations of radionuclide transport processes and techniques for calculating dose. The exercise has focused on the ways in which key FEPs are represented with the intention of determining the robustness or otherwise of existing representations. This has been achieved by applying a well defined dataset representative of a Central European inland valley. Human habits and lifestyle are chosen to be representative of a subsistence agricultural community. Climatic conditions are those of the present day. Many of the conclusions have relevance beyond the immediate concerns of the Central European biospheres and, although care should be exercised when terms of reference differ greatly from the system detailed here, much has been learned which has wider applicability. The exercise has successfully compared not only the behaviour of biosphere models for waste disposal assessments, but has also provided the

  16. Dose assessment for sheep exposed to fallout from nuclear test Nancy

    Energy Technology Data Exchange (ETDEWEB)

    Sasser, L.B.; Soldat, J.K.; Kennedy, W.E. Jr.; Murphy, D.W.

    1982-10-01

    Radiation doses were estimated for sheep wintering on Nevada ranges during the testing at the Nevada Test Site of the nuclear weapon Nancy on March 24, 1953. Exposure pathways considered were inhalation of radionuclides from both cloud passage and resuspension, external exposure of the total body and skin, and ingestion of contaminated forage and soil. Physiological, metabolic, and dosimetric data needed for these calculations were obtained from data appropriate for the sheep. Dose rate and radionuclide deposition values for shot Nancy were used. Radionuclide deposition and retention on the desert vegetation were obtained from data collected during several nuclear tests at the Nevada Test Site. Existing dosimetric computer programs, whose libraries were modified to include the sheep data, and specially developed models were used to estimate the dose commitment for the sheep. The total-body dose for reference sheep located within the 40-mR/hr (H+12) isopleth from all modes of exposure was estimated to be 2.6 rad. Ingestion of fallout on edible vegetation contributed the majority of the dose, whereas inhalation of radionuclides and consumption of contaminated soil from the ground contributed little to the internal doses. The dose to the thyroid of ewes from radioiodine and other radionuclides reaching the thyroid was approximately 400 rad. The calculated uniform dose to the reticulo-rumen was 4 rad; however, if fallout particles were assumed to concentrate in the ventral rumen, a localized dose of 200 rad could have been received by the rumen wall. Estimated dose to the bare skin of ewes was 120 rad. The dose to the fetal thyroid from radioiodine ingested by a pregnant ewe grazing at a location where the dose rate was 40 mR/hr (H+12) was estimated to be 700 rad, or approximately twice the dose to the maternal thyroid.

  17. Closed reduction and fluoroscopic-assisted percutaneous pinning of 42 physeal fractures in 37 dogs and 4 cats.

    Science.gov (United States)

    Boekhout-Ta, Christina L; Kim, Stanley E; Cross, Alan R; Evans, Richard; Pozzi, Antonio

    2017-01-01

    To report complications and clinical outcome of dogs and cats that underwent fluoroscopic-assisted percutaneous pinning (FAPP) of physeal fractures. Retrospective study. Client-owned dogs (n = 37) and cats (n = 4). Records (August 2007-August 2014) of physeal fractures treated with FAPP in 3 hospitals were evaluated. Data collected included signalment, fracture characteristics (etiology, location, duration, Salter-Harris classification, preoperative and postoperative displacement), surgical information (implant size, surgical duration), and outcome assessment information (functional outcome, radiographic outcome, and complications). The majority of animals (92%) were classified as full functional outcome. No significant predictors of functional outcome were identified. The overall complication rate was 15% (n = 6). Elective pin removal rate was 41% (n = 17). Goniometry and limb circumference measurements of the affected and contralateral limbs were not significantly different in dogs for which measurements were obtained. Seventeen of 18 animals (16 dogs, 2 cats) measured had bone length changes on follow-up radiographs. FAPP is associated with an excellent functional outcome in a narrow selection of fracture configurations, specifically those with minimal displacement and for which anatomical alignment can be achieved with closed reduction. © 2016 The American College of Veterinary Surgeons.

  18. Dose Assessment and Considerations When a Radioactive Seed is Unrecoverable in a Breast Surgical Patient.

    Science.gov (United States)

    Harvey, Richard P

    2016-11-01

    Excision of non-palpable breast tumors in cancer patients has been routinely performed using surgical clips and wires placed under mammographic or ultrasound guidance. An alternative method exists for performing these surgeries without surgical wires and this approach has become more widely used at Oncology Centers in the United States. Roswell Park Cancer Institute (RPCI) performs many of their breast surgeries with radioactive seeds and has enjoyed favorable outcomes along with an enhanced patient experience. There are some inherent difficulties with using radioactive seeds, and seed tracking can be a problem during surgical procedures. When a seed is misplaced, an extensive search is conducted in an effort to locate the misplaced seed. Every attempt to recover these radioactive seeds should be made unless patient safety is jeopardized. If the seed is unrecoverable, then a dose assessment must be performed and corrective action determined. It is important to have adequate policies and procedures in place to prevent these rare occurrences. They should be treated as a radioactive medical event.

  19. Radioactivity concentration variation with depth and assessment of workers' doses in selected mining sites

    Directory of Open Access Journals (Sweden)

    C.U. Nwankwo

    2015-04-01

    Full Text Available Mining workers are exposed to radiation in the process of extracting minerals from the earth crust. In this research, activity concentration of the radionuclides in samples collected at different depths in Komu (0–220 ft and Olode (0–30 ft mining sites, Oyo State, Nigeria and the associated workers' radiological risks were assessed. Gemstones from these sites are mined for local and international markets. The radionuclide contents of the samples were determined using Gamma spectroscopy technique. At Komu, 238U and 232Th concentrations, with few exceptions, increased with depth while that of 40K had no defined pattern. At Olode site, 238U and 232Th concentrations decreased with depth while that of 40K was almost constant. Internal hazard indices at Komu in some cases indicated an unacceptable level of risk to workers. Workers' doses would have been underestimated by between 12 and 55% if the activity concentrations of samples in the pit were not included in the calculation.

  20. Post-Remediation Radiological Dose Assessment, Linde Site, Tonawanda, New York

    Energy Technology Data Exchange (ETDEWEB)

    Kamboj, Sunita [Argonne National Lab. (ANL), Argonne, IL (United States); Durham, Lisa A. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2014-06-01

    A post-remediation radiological dose assessment was conducted for the Formerly Utilized Sites Remedial Action Program (FUSRAP) Linde Site by using the measured residual concentrations of the radionuclides of concern following the completion of the soils remedial action. The site’s FUSRAP-related contaminants of concern (COCs) are radionuclides associated with uranium processing activities conducted by the Manhattan Engineer District (MED) in support of the Nation’s early atomic energy and weapons program and include radium-226 (Ra-226), thorium-230 (Th-230), and total uranium (Utotal). Remedial actions to address Linde Site soils and structures were conducted in accordance with the Record of Decision for the Linde Site, Tonawanda, New York (ROD) (USACE 2000a). In the ROD, the U.S. Army Corps of Engineers (USACE) determined that the cleanup standards found in Title 40, Part 192 of the Code of Federal Regulations (40 CFR Part 192), the standards for cleanup of uranium mill sites designated under the Uranium Mill Tailings Radiation Control Act (UMTRCA), and the Nuclear Regulatory Commission (NRC) standards for decommissioning of licensed uranium and thorium mills, found in 10 CFR Part 40, Appendix A, Criterion 6(6), are Applicable or Relevant and Appropriate Requirements (ARARs) for cleanup of MED-related contamination at the Linde Site. The major elements of this remedy will involve excavation of the soils with COCs above soil cleanup levels and placement of clean materials to meet the other criteria of 40 CFR Part 192.

  1. Assessment of safe bioactive doses of Foeniculum vulgare Mill. essential oil from Portugal.

    Science.gov (United States)

    Cabral, C; Miranda, M; Gonçalves, M J; Cavaleiro, C; Cruz, M T; Salgueiro, L

    2017-03-02

    This study was designed to evaluate the antifungal activity of Foeniculum vulgare essential oil; concomitantly, the safety of bioactive doses was also unveiled, for the first time, in several mammalian cells. The chemical characterisation was made by GC and GC-MS. Antifungal activity was evaluated against yeasts, dermatophytes and Aspergillus strains and germ tube inhibition assay was evaluated using Candida albicans. Cell viability was assessed by the MTT assay. The main constituents of the oil are E-anetol (47%), α-phellandrene (11%), α-pinene (10.1%) and fenchone (10.8%). The oil was more active against Cryptococcus neoformans and C. albicans (MICs 0.32-0.64 μL/mL) and the filamentation of C. albicans was totally inhibited with 0.08 μL/mL. The oil is safe for keratinocytes, hepatocytes and fibroblasts in concentrations up to 1.25 μL/mL, and to macrophages up to 0.64 μL/mL. These findings highlight safe bioactive concentrations that should be deeper investigated for further application in pharmaceutical industry.

  2. Proton Dose Assessment to the Human Eye Using Monte Carlo N-Particle Transport Code (MCNPX)

    Science.gov (United States)

    2006-08-01

    objective of this project was to develop a simple MCNPX model of the human eye to approximate dose delivered from proton therapy. The calculated dose...computer code MCNPX that approximates dose delivered during proton therapy. The calculations considered proton interactions and secondary interactions...Volume Calculation The MCNPX code has limited ability to compute the volumes of defined cells. The dosimetric volumes in the outer wall of the eye are

  3. {sup 226} Ra committed effective dose assessment for osteoporosis treatment with `Gran-White` dolomite

    Energy Technology Data Exchange (ETDEWEB)

    Pecequilo, Brigitte R.S.; Campos, Marcia P. de [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    1997-12-01

    A total of 6 dolomite samples were prepared for activity concentration measurement by using high resolution gamma-ray spectrometry. The calculated average specific activity of {sup 226} Ra was 4.34 Bq/kg. The committed effective dose due to the Ra-226 specific activity in dolomite was performed following the ICRP 30 and ICRP 61 procedures and dose conversion factors. Values of 1.95 x 10{sup -6} Sv were obtained for committed effective dose and 5.93 x 10{sup -5} Sv for committed dose equivalent in the bone surface. (author). 9 refs., 2 tabs.

  4. Measurements of radioactivity and dose assessments in some building materials in Bitlis, Turkey.

    Science.gov (United States)

    Kayakökü, Halime; Karatepe, Şule; Doğru, Mahmut

    2016-09-01

    In this study, samples of perlite, pumice and Ahlat stones (Ignimbrite) extracted from mines in Bitlis and samples of other building materials produced in facilities in Bitlis were collected and analyzed. Activity concentrations of (226)Ra, (232)Th and (40)K in samples of building materials were measured using NaI detector (NaI(Tl)) with an efficiency of 24%. The radon measurements of building material samples were determined using CR-39 nuclear track detectors. (226)Ra, (232)Th and (40)K radioactivity concentrations ranged from (29.6±5.9 to 228.2±38.1Bq/kg), (10.8±5.4 to 95.5±26.1Bq/kg) and (249.3±124.7 to 2580.1±266.9Bq/kg), respectively. Radon concentration, radium equivalent activities, absorbed dose rate, excess lifetime cancer risk and the values of hazard indices were calculated for the measured samples to assess the radiation hazards arising from using those materials in the construction of dwellings. Radon concentration ranged between 89.2±12.0Bq/m(3) and 1141.0±225.0Bq/m(3). It was determined that Raeq values of samples conformed to world standards except for perlite and single samples of brick and Ahlat stone. Calculated values of absorbed dose rate ranged from 81.3±20.5 to 420.6±42.8nGy/h. ELCR values ranged from (1.8±0.3)×10(-3) to (9.0±1.0)×10(-3). All samples had ELCR values higher than the world average. The values of Hin and Hex varied from 0.35±0.11 to 1.78±0.18 and from 0.37±0.09 to 1.17±0.13, respectively. The results were compared with standard radioactivity values determined by international organizations and with similar studies. There would be a radiation risk for people living in buildings made of perlite, Ahlat-1 and Brick-3.

  5. Solid-state fluoroscopic imager for high-resolution angiography: parallel-cascaded linear systems analysis.

    Science.gov (United States)

    Vedantham, Srinivasan; Karellas, Andrew; Suryanarayanan, Sankararaman

    2004-05-01

    Cascaded linear systems based modeling techniques have been used in the past to predict important system parameters that have a direct impact on image quality. Such models are also useful in optimizing system parameters to improve image quality. In this work, detailed analysis of a solid-state fluoroscopic imaging system intended for high-resolution angiography is presented with the use of such a model. The imaging system analyzed through this model uses four 8 x 8 cm three-side buttable interlined charge-coupled devices (CCDs) specifically designed for high-resolution angiography and tiled in a seamless fashion to achieve a field of view (FOV) of 16 x 16 cm. Larger FOVs can be achieved by tiling more CCDs in a similar manner. The system employs a CsI:Tl scintillator coupled to the CCDs by straight (nontapering) fiberoptics and can potentially be operated in 78, 156, or 234 microm pixel pitch modes. The system parameters analyzed through this model include presampling modulation transfer function, noise power spectrum, and detective quantum efficiency (DQE). The results of the simulations performed indicate that DQE(0) in excess of 0.6 is achievable, with the imager operating at 156 microm pixel pitch, 30 frames/s, and employing a 450-microm-thick CsI:Tl scintillator, even at a low fluoroscopic exposure rate of 1 microR/frame. Further, at a nominal fluoroscopic exposure rate of 2.5 microR/frame there was no noticeable degradation of the DQE even at the 78 microm pixel pitch mode suggesting that it is feasible to perform high-resolution angiography hitherto unattainable in clinical practice.

  6. Quality specifications for glucose meters: assessment by simulation modeling of errors in insulin dose.

    Science.gov (United States)

    Boyd, J C; Bruns, D E

    2001-02-01

    Proposed quality specifications for glucose meters allow results to be in error by 5-10% or more of the "true" concentration. Because meters are used as aids in the adjustment of insulin doses, we aimed to characterize the quantitative effect of meter error on the ability to identify the insulin dose appropriate for the true glucose concentration. Using Monte Carlo simulation, we generated random "true" glucose values within defined intervals. These values were converted to "measured" glucose values using mathematical models of glucose meters having defined imprecision (CV) and bias. For each combination of bias and imprecision, 10,000-20,000 true and measured glucose concentrations were matched with the corresponding insulin doses specified by selected insulin-dosing regimens. Discrepancies in prescribed doses were counted and their frequencies plotted in relation to bias and imprecision. For meters with a total analytical error of 5%, dosage errors occurred in approximately 8-23% of insulin doses. At 10% total error, 16-45% of doses were in error. Large errors of insulin dose (two-step or greater) occurred >5% of the time when the CV and/or bias exceeded 10-15%. Total dosage error rates were affected only slightly by choices of sliding scale among insulin dosage rules or by the range of blood glucose. To provide the intended insulin dosage 95% of the time required that both the bias and the CV of the glucose meter be <1% or <2%, depending on mean glucose concentrations and the rules for insulin dosing. Glucose meters that meet current quality specifications allow a large fraction of administered insulin doses to differ from the intended doses. The effects of such dosage errors on blood glucose and on patient outcomes require study.

  7. Nonmonotonic Dose Responses as They Apply to Estrogen, Androgen, and Thyroid Pathways and EPA Testing and Assessment Procedures

    Science.gov (United States)

    A state of the science document providing a judgment on the degree to which nonmonotonic dose-responses are evidenced in the scientific literature and to evaluate the extent to which they may impact U.S. EPA’s chemical testing and risk assessment.

  8. Assessment of CT dose to the fetus and pregnant female patient using patient-specific computational models

    DEFF Research Database (Denmark)

    Xie, Tianwu; Poletti, Pierre-Alexandre; Platon, Alexandra

    2017-01-01

    PURPOSE: This work provides detailed estimates of the foetal dose from diagnostic CT imaging of pregnant patients to enable the assessment of the diagnostic benefits considering the associated radiation risks. MATERIALS AND METHODS: To produce realistic biological and physical representations of ...

  9. Progress in Assessing Air Pollutant Risks from In Vitro Exposures: Matching Ozone Dose and Effect in Human Air Way Cells

    Science.gov (United States)

    In vitro exposures to air pollutants could, in theory, facilitate a rapid and detailed assessment of molecular mechanisms of toxicity. However, it is difficult to ensure that the dose of a gaseous pollutant to cells in tissue culture is similar to that of the same cells during in...

  10. Avoiding Pitfalls in the Use of the Benchmark Dose Approach to Chemical Risk Assessments; Some Illustrative Case Studies (Presentation)

    Science.gov (United States)

    The USEPA's benchmark dose software (BMDS) version 1.2 has been available over the Internet since April, 2000 (epa.gov/ncea/bmds.htm), and has already been used in risk assessments of some significant environmental pollutants (e.g., diesel exhaust, dichloropropene, hexachlorocycl...

  11. Benchmark Dose Analysis from Multiple Datasets: The Cumulative Risk Assessment for the N-Methyl Carbamate Pesticides

    Science.gov (United States)

    The US EPA’s N-Methyl Carbamate (NMC) Cumulative Risk assessment was based on the effect on acetylcholine esterase (AChE) activity of exposure to 10 NMC pesticides through dietary, drinking water, and residential exposures, assuming the effects of joint exposure to NMCs is dose-...

  12. Technical and imaging report: fluoroscopic guidance for diagnosis and treatment of lumbar synovial cyst.

    Science.gov (United States)

    Rauchwerger, Jacob J; Candido, Kenneth D; Zoarski, Gregg H

    2011-01-01

    Lumbar synovial cysts can be a source of low back pain with or without radiculopathy depending upon the size and location of the mass. Options for treatment range from analgesics to surgery, depending upon the degree of nerve root or spinal cord impingement. Attempts at minimally invasive treatment such as computed tomography-assisted aspiration and cyst rupture are documented in the radiology literature with varying degrees of reported success. This case report is the first to document the fluoroscopically-guided management of a lumbar synovial cyst in the pain medicine literature and highlights the knowledge and technical skills required when treating such cases. © 2010 World Institute of Pain.

  13. Transrectal Drainage of Deep Pelvic Abscesses Using a Combined Transrectal Sonographic and Fluoroscopic Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Kyung Soon; Lee, Eun Jung; Ko, Ji Ho; Joh, Young Duk [Gospel Hospital, Kosin University College of Medicine, Busan (Korea, Republic of); Jung, Gyoo Sik [Ulsan Hospital, Ulsan (Korea, Republic of)

    2005-09-15

    To evaluate the feasibility and clinical efficacy of transrectal drainage of a deep pelvic abscess using combined transrectal sonographic and fluoroscopic guidance. From March 1995 and August 2004, 17 patients (9 men; 8 women; mean age, 39 years) suffering from pelvic pain, fever and leukocytosis were enrolled in this retrospective study. Ultrasound (US) or computed tomography (CT), which was obtained prior to the procedure, showed pelvic fluid collections that were deemed unapproachable by the percutaneous trans abdominal routes. Transrectal drainage of the pelvic abscess was performed under combined transrectal sonographic and fluoroscopic guidance. The causes of the deep pelvic abscess were postoperative complications (n=7), complications associated with radiation (n=3) and chemotherapy (n=1) as well as unknown causes (n=6). A 7.5-MHz end-firing transrectal US probe with a needle biopsy guide attachment was advanced into the rectum. Once the abscess was identified, a needle was advanced via the biopsy guide and the abscess was punctured. Under US guidance, either a 0.018'or 0.035' guide wire was passed through the needle in the abscess. Under fluoroscopic guidance, the tract was dilated to the appropriate diameter with sequential fascial dilators, and a catheter was placed over the guide wire within the abscess. Clinical success of drainage was determined by a combination closure of the cavity on the follow up images and diminished leukocytosis. The technical and clinical success rate, complications, and patient's discomfort were analyzed. Drainage was technically successful in all patients and there were no serious complications. Surgery was eventually performed in two cases due to fistular formation with the rectum and leakage of the anastomosis site. The procedure was well tolerated in all but one patient who complained of discomfort while the catheter was inserted . The catheter did not interfere with defecation and there was no incidence of

  14. Fluoroscopically-guided micropuncture femoral artery access for large-caliber sheath insertion.

    Science.gov (United States)

    Cilingiroglu, Mehmet; Feldman, Ted; Salinger, Michael H; Levisay, Justin; Turi, Zoltan G

    2011-04-01

    Over the last decade, significant developments have been made in the treatment of structural heart disease. Some of these techniques require placement of large arterial sheaths for device delivery. Optimal vascular access is essential for successful large-vessel sheath insertion as well as to avoid vascular complications. The critical step for ideal percutaneous vessel entry is single anterior wall-only puncture of the common femoral artery in a location above the femoral bifurcation and below the inguinal ligament. We describe a fluoroscopically-guided micropuncture technique for accurate placement of large-caliber arterial sheaths.

  15. A Technical Approach to Expedited Processing of NTPR Radiation Dose Assessments

    Science.gov (United States)

    2011-10-01

    Dose Cohort .............................................................................. 87 B-2 Treatment of Exclusions...magnitude given the same scenario of exposure. • Uniformity in the treatment of upper-bound doses is maintained. • Approved NTPR standard methods...Pharynx (140-149) TONSILS TONSILS Tonsils ET Region+ Surrogate Oral Cavity and Pharynx (140-149) TRACHEA TRACHEA Trachea Lung Surrogate Lung (162

  16. Premature chromosome condensation (PCC) assay for dose assessment in mass casualty accidents.

    Science.gov (United States)

    Lindholm, Carita; Stricklin, Daniela; Jaworska, Alicja; Koivistoinen, Armi; Paile, Wendla; Arvidsson, Eva; Deperas-Standylo, Joanna; Wojcik, Andrzej

    2010-01-01

    The study was undertaken to establish a dose calibration curve for a practical PCC ring assay and to apply it in a simulated mass casualty accident. The PCC assay was validated against the conventional dicentric assay. A linear relationship was established for PCC rings after (60)Co gamma irradiation with doses up to 20 Gy. In the simulated accident experiment, 62 blood samples were analyzed with both the PCC ring assay and the conventional dicentric assay, applying a triage approach. Samples received various uniform and non-uniform (10-40% partial-body) irradiations up to doses of 13 Gy. The results indicated that both assays yielded good dose estimates for the whole-body exposure scenario, although in the lower-dose range (0-6 Gy) dicentric scoring resulted in more accurate whole-body estimates, whereas PCC rings were better in the high-dose range (>6 Gy). Neither assay was successful in identifying partial-body exposures, most likely due to the low numbers of cells scored in the triage mode. In conclusion, the study confirmed that the PCC ring assay is suitable for use as a biodosimeter after whole-body exposure to high doses of radiation. However, there are limitations for its use in the triage of people exposed to high, partial-body doses.

  17. Verification of Caregraph (trademark) Peak Skin Dose Data Using Radiochromic Film

    Science.gov (United States)

    2005-06-15

    during the experimental exposures. The phantom is 155 cm (5 ft. 1 in.) tall and weighs 55 kg (110 lb).34 It is transected horizontally into 2.5 cm...Techniques to estimate radiation dose to skin during fluoroscopically guided procedures, Phelps, B. (ed), AAPM Summer School Proceedings, Madison

  18. Short-term outcome of fluoroscopic-guided steroid injection therapy of lumber facet cyst-induced radicular pain

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Mi Ri; Kwon, Jong Won; Lee, Jong Seo; Kim, Eu Sang [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2015-04-15

    To determine the short-term effect of fluoroscopic-guided steroid injection therapy of lumbar facet cyst-induced radicular pain. Seventeen patients with radiculopathy due to lumbar synovial cysts, who were treated with fluoroscopically guided injection, were retrospectively evaluated. All plain radiographic images and MR images before the therapy were reviewed. Five patients underwent only the facet joint injection, whereas twelve patients underwent the facet joint injection with perineural injection therapy. The clinical course of pain was evaluated on the first follow-up after therapy. Effective pain relief was achieved in 11 (64.7%) of the 17 patients. Among 12 patients who underwent facet joint injection with perineural injection, 9 patients (75%) had an effective pain relief. Of 5 patients, 2 (40%) patients only took the facet joint injection and had an effective pain relief. Fluoroscopic-guided steroid injection therapy shows a good short-term effect in patients with symptomatic lumbar facet joint synovial cysts.

  19. T-Fastener Gastropexy and Percutaneous Gastrostomy Under CT-Fluoroscopic Guidance in a Patient with Partial Gastrectomy

    Directory of Open Access Journals (Sweden)

    Siu-Cheung Chan

    2006-01-01

    Full Text Available The real-time images of computed tomography (CT-fluoroscopy provide an excellent means of guidance for percutaneous interventions. We describe the performance of T-fastener gastropexy and percutaneous gastrostomy under CT-fluoroscopic guidance in a 59-year-old woman who had received total pharyngolaryngectomy for hypopharyngeal cancer and partial gastrectomy with Billroth II anastomosis for bleeding gastric ulcer 10 years before this operation. The previous gastric operation altered the gastrointestinal anatomy and made conventional fluoroscopic-guided percutaneous gastrostomy extremely difficult and risky. The T-fastener gastropexy and percutaneous gastrostomy were accomplished smoothly in a single session using CT-fluoroscopic guidance. This modified method of percutaneous gastrostomy may be useful in patients with anatomic distortion due to previous gastric surgery.

  20. Fluoroscopic bone fragment tracking for surgical navigation in femur fracture reduction by incorporating optical tracking of hip joint rotation center.

    Science.gov (United States)

    Nakajima, Yoshikazu; Tashiro, Takahito; Sugano, Nobuhiko; Yonenobu, Kazuo; Koyama, Tsuyoshi; Maeda, Yuki; Tamura, Yuichi; Saito, Masanobu; Tamura, Shin'ichi; Mitsuishi, Mamoru; Sugita, Naohiko; Sakuma, Ichiro; Ochi, Takahiro; Matsumoto, Yoichiro

    2007-09-01

    A new method for fluoroscopic tracking of a proximal bone fragment in femoral fracture reduction is presented. The proposed method combines 2-D and 3-D image registration from single-view fluoroscopy with tracking of the head center position of the proximal femoral fragment to improve the accuracy of fluoroscopic registration without the need for repeated manual adjustment of the C-arm as required in stereo-view registrations. Kinematic knowledge of the hip joint, which has a positional correspondence with the femoral head center and the pelvis acetabular center, allows the position of the femoral fragment to be determined from pelvis tracking. The stability of the proposed method with respect to fluoroscopic image noise and the desired continuity of the fracture reduction operation is demonstrated, and the accuracy of tracking is shown to be superior to that achievable by single-view image registration, particularly in depth translation.

  1. Biosphere modelling for dose assessments of radioactive waste repositories. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Klos, R. [Paul Scherrer Inst., Wuerenlingen (Switzerland)] [and others

    1996-09-01

    The aims of the Complementary Studies Working Group were: to investigate and explain differences which exist between contemporary models with respect to how, for a given test case, they represent the modelled Features, Events and Processes (FEPs) and how the nature of these representations affects the calculational end-points; to determine the most appropriate ways of representing key FEPs; to identify where knowledge needs to be improved to give better representations of these key FEPs in the future and where simplifications of existing formulations might be possible; to show that the modelling undertaken is suitable for purpose, in that it is robust and that it is unlikely that the radiological consequences calculated by the models would be underestimated (so that any conservative bias in the models is justified); to build confidence in the available modelling tools; to extend the work undertaken in the first phase of BIOMOVS to include consideration of radiological dose. Ten modelling groups from Western Europe and Canada have participated, revealing a variety of representations of radionuclide transport processes and techniques for calculating dose. The exercise has focused on the ways in which key FEPs are represented with the intention of determining the robustness or otherwise of existing representations. This has been achieved by applying a well defined dataset representative of a Central European inland valley. Human habits and lifestyle are chosen to be representative of a subsistence agricultural community. Climatic conditions are those of the present day. Many of the conclusions have relevance beyond the immediate concerns of the Central European biospheres and, although care should be exercised when terms of reference differ greatly from the system detailed here, much has been learned which has wider applicability. The exercise has successfully compared not only the behaviour of biosphere models for waste disposal assessments, but has also provided the

  2. Evaluation of low-dose dual energy computed tomography for in vivo assessment of renal/ureteric calculus composition.

    Science.gov (United States)

    Mahalingam, Harshavardhan; Lal, Anupam; Mandal, Arup K; Singh, Shrawan Kumar; Bhattacharyya, Shalmoli; Khandelwal, Niranjan

    2015-08-01

    This study aimed to assess the accuracy of low-dose dual-energy computed tomography (DECT) in predicting the composition of urinary calculi. A total of 52 patients with urinary calculi were scanned with a 128-slice dual-source DECT scanner by use of a low-dose protocol. Dual-energy (DE) ratio, weighted average Hounsfield unit (HU) of calculi, radiation dose, and image noise levels were recorded. Two radiologists independently rated study quality. Stone composition was assessed after extraction by Fourier transform infrared spectroscopy (FTIRS). Analysis of variance was used to determine if the differences in HU values and DE ratios between the various calculus groups were significant. Threshold cutoff values to classify the calculi into separate groups were identified by receiver operating characteristic curve analysis. A total of 137 calculi were detected. FTIRS analysis differentiated the calculi into five groups: uric acid (n=17), struvite (n=3), calcium oxalate monohydrate and dihydrate (COM-COD, n=84), calcium oxalate monohydrate (COM, n=28), and carbonate apatite (n=5). The HU value could differentiate only uric acid calculi from calcified calculi (p80% sensitivity and specificity to differentiate them. The DE ratio could not differentiate COM from COM-COD calculi. No study was rated poor in quality by either of the observers. The mean radiation dose was 1.8 mSv. Low-dose DECT accurately predicts urinary calculus composition in vivo while simultaneously reducing radiation exposure without compromising study quality.

  3. An assessment of the secondary neutron dose in the passive scattering proton beam facility of the national cancer center

    Energy Technology Data Exchange (ETDEWEB)

    Han, Sang Eun [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Cho, Gyuseong [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Lee, Se Byeong [Proton Therapy Center, National Cancer Center, Goyang (Korea, Republic of)

    2017-06-15

    The purpose of this study is to assess the additional neutron effective dose during passive scattering proton therapy. Monte Carlo code (Monte Carlo N-Particle 6) simulation was conducted based on a precise modeling of the National Cancer Center's proton therapy facility. A three-dimensional neutron effective dose profile of the interior of the treatment room was acquired via a computer simulation of the 217.8-MeV proton beam. Measurements were taken with a 3He neutron detector to support the simulation results, which were lower than the simulation results by 16% on average. The secondary photon dose was about 0.8% of the neutron dose. The dominant neutron source was deduced based on flux calculation. The secondary neutron effective dose per proton absorbed dose ranged from 4.942 ± 0.031 mSv/Gy at the end of the field to 0.324 ± 0.006 mSv/Gy at 150 cm in axial distance.

  4. Biomarkers of internal dose for the assessment of environmental exposure to benzene.

    Science.gov (United States)

    Lovreglio, Piero; D'Errico, Maria Nicolà; Fustinoni, Silvia; Drago, Ignazio; Barbieri, Anna; Sabatini, Laura; Carrieri, Mariella; Apostoli, Pietro; Soleo, Leonardo

    2011-10-01

    The urinary excretion of t,t-muconic acid (t,t-MA), S-phenylmercapturic acid (SPMA) and urinary benzene and the influence of a smoking habit and of exposure to urban traffic on the urinary excretion of these biomarkers were investigated in 137 male adults from the general population. All subjects were not occupationally exposed to benzene and resident in two cities in Puglia (Southern-Italy). Environmental exposure to benzene was measured using passive personal samplers. The biomarkers t,t-MA, SPMA and urinary benzene were determined in urine samples collected from each subject at the end of the environmental sampling. The percentage of cases above the limit of detection was higher for SPMA and urinary benzene in smokers than in non-smokers, and for airborne benzene and urinary benzene in subjects exposed to urban traffic. Airborne benzene was correlated with the time spent in urban traffic during the environmental sampling. Among the biomarkers, urinary benzene was found to be correlated with airborne benzene only in non-smokers, and with the time spent in urban traffic, both in smokers and non-smokers considered together, and in non-smokers only. Finally, multiple regression analysis showed that the urinary excretion of all the biomarkers was dependent on the number of cigarettes smoked per day and, for urinary benzene, also on the time spent in urban traffic. In conclusion, urinary benzene seems to be a more valid biomarker than t,t-MA and SPMA to assess environmental exposure to extremely low concentrations of benzene. Cigarette smoking prevailed over traffic exhaust fumes in determining the internal dose of benzene.

  5. Assessment of a twice dosing regimen both before and after partial hepatectomy in the rat liver micronucleus test.

    Science.gov (United States)

    Itoh, Satoru; Igarashi, Miyuki; Nagata, Mayumi; Hattori, Chiharu

    2015-04-01

    The liver micronucleus test is an important method to detect in vivo genotoxicants, especially those that require metabolic activation for their genotoxicity. We have already reported that structural or numerical chromosome aberration inducers have to be given before or after partial hepatectomy, respectively, to detect their genotoxicity in the liver of rats. In the present study, we assessed a twice dosing regimen, in which the genotoxicant is dosed both before and after partial hepatectomy, using the four chromosome aberration inducers used in the previous study. Two structural chromosome aberration inducers (diethylnitrosamine and 1,2-dimethylhydrazine) and two numerical chromosome aberration inducers (colchicine and carbendazim) were used. The genotoxicant was administered to 8-week old male F344 rats one day before and again one day after the partial hepatectomy and hepatocytes were isolated 3 days after second dosing (4 days after the partial hepatectomy). As a result, all genotoxicants (structural or numerical chromosome aberration inducers) caused a dose-dependent statistically significant increase in the incidence of micronucleated hepatocytes when given both before and after partial hepatectomy. No marked difference was observed in general toxicity, relative liver weight and cell classification between single dosing regimens and twice dosing regimen of the genotoxicants. These results confirm that the twice dosing regimen, in which the test compound is dosed both before and after partial hepatectomy, can detect in vivo induction of micronucleated hepatocytes by structural or numerical chromosome aberration inducers qualitatively similar to their appropriate regimen in which the test compound is administered either before or after partial hepatectomy.

  6. Assessment of Environmental Gamma Radiation Dose Rate in Ardabil and Sarein in 2009

    Directory of Open Access Journals (Sweden)

    M Alighadri

    2011-10-01

    Full Text Available Background and Objectives: Gamma rays, the most energetic photons within the any other wave in the electromagnetic spectrum, pose enough energy to form charged particles and adversely affect human health. Provided that the external exposure of human beings to natural environmental gamma radiation normally exceeds that from all man-made sources combined, environmental gamma dose rate and corresponding annual effective dose were determined in the cities of Ardabil and Sar Ein.Materials and Methods: Outdoor environmental gamma dose rates were measured using an Ion Chamber Survey Meter in 48 selected locations (one in city center and the remaining in cardinal and ordinal directions in Ardabil and Sar Ein. Ten more locations were monitored along the hot springs effluent in Sar Ein. Measurements of gamma radiation dose rate were performed at 20 and 100 cm above the ground for a period of one hour.Results: Average outdoor environmental gamma dose rate were determined as 265, 219, and 208  for Ardabil, Sar Ein, and along the hot spring effluent, respectively. The annual affective dose for Ardabil and Sar Ein residents were estimated to be 1.45 and 1.39 mSv, respectively.Conclusion: Calculated annual effective dose of 1.49 and 1.35 are appreciably higher than the population weighted average exposure to environmental gamma radiation worldwide and that analysis of soil content to different radionuclide is suggested.

  7. Dose Assessment in Computed Tomography Examination and Establishment of Local Diagnostic Reference Levels in Mazandaran, Iran

    Directory of Open Access Journals (Sweden)

    Janbabanezhad Toori A.

    2015-12-01

    Full Text Available Background: Medical X-rays are the largest man-made source of public exposure to ionizing radiation. While the benefits of Computed Tomography (CT are well known in accurate diagnosis, those benefits are not risk-free. CT is a device with higher patient dose in comparison with other conventional radiation procedures. Objective: This study is aimed at evaluating radiation dose to patients from Computed Tomography (CT examination in Mazandaran hospitals and defining diagnostic reference level (DRL. Methods: Patient-related data on CT protocol for four common CT examinations including brain, sinus, chest and abdomen & pelvic were collected. In each center, Computed Tomography Dose Index (CTDI measurements were performed using pencil ionization chamber and CT dosimetry phantom according to AAPM report No. 96 for those techniques. Then, Weighted Computed Tomography Dose Index (CTDIW, Volume Computed Tomography Dose Index (CTDI vol and Dose Length Product (DLP were calculated. Results: The CTDIw for brain, sinus, chest and abdomen & pelvic ranged (15.6- 73, (3.8-25. 8, (4.5-16.3 and (7-16.3, respectively. Values of DLP had a range of (197.4-981, (41.8-184, (131-342.3 and (283.6-486 for brain, sinus, chest and abdomen & pelvic, respectively. The 3rd quartile of CTDIW, derived from dose distribution for each examination is the proposed quantity for DRL. The DRLs of brain, sinus, chest and abdomen & pelvic are measured 59.5, 17, 7.8 and 11 mGy, respectively. Conclusion: Results of this study demonstrated large scales of dose for the same examination among different centers. For all examinations, our values were lower than international reference doses.

  8. Effect of Total Dose of Lidocaine on Duration of Adductor Canal Block, Assessed by Different Test Methods

    DEFF Research Database (Denmark)

    Jæger, Pia; Koscielniak-Nielsen, Zbigniew J; Hilsted, Karen Lisa

    2016-01-01

    BACKGROUND: The binary aims of this study were to investigate the effect of total dose of lidocaine on duration of an adductor canal block (ACB) and to validate different methods used to assess nerve blocks. METHODS: We performed 2 blinded, randomized, controlled crossover trials, including healthy......, young men. In study 1, 14 subjects received 4 ACBs with saline and 40, 80, and 160 mg lidocaine. In study 2, 14 new subjects received 2 ACBs with 100 and 300 mg lidocaine. We kept volume constant at 20 mL for all blocks, only altering concentration. ACB duration was assessed every hour postblock using......: In study 1, block duration assessed by mechanical discrimination differed significantly when comparing the 40-mg dose with the 80-mg dose (mean difference, 1.15 hours; 99% confidence interval [CI], 0.38–2.09 hours) and with the 160-mg dose (mean difference, 0.92 ours; 99% CI, 0.17–1.62). However...

  9. A biosphere modeling methodology for dose assessments of the potential Yucca Mountain deep geological high level radioactive waste repository.

    Science.gov (United States)

    Watkins, B M; Smith, G M; Little, R H; Kessler, J

    1999-04-01

    Recent developments in performance standards for proposed high level radioactive waste disposal at Yucca Mountain suggest that health risk or dose rate limits will likely be part of future standards. Approaches to the development of biosphere modeling and dose assessments for Yucca Mountain have been relatively lacking in previous performance assessments due to the absence of such a requirement. This paper describes a practical methodology used to develop a biosphere model appropriate for calculating doses from use of well water by hypothetical individuals due to discharges of contaminated groundwater into a deep well. The biosphere model methodology, developed in parallel with the BIOMOVS II international study, allows a transparent recording of the decisions at each step, from the specification of the biosphere assessment context through to model development and analysis of results. A list of features, events, and processes relevant to Yucca Mountain was recorded and an interaction matrix developed to help identify relationships between them. Special consideration was given to critical/potential exposure group issues and approaches. The conceptual model of the biosphere system was then developed, based on the interaction matrix, to show how radionuclides migrate and accumulate in the biosphere media and result in potential exposure pathways. A mathematical dose assessment model was specified using the flexible AMBER software application, which allows users to construct their own compartment models. The starting point for the biosphere calculations was a unit flux of each radionuclide from the groundwater in the geosphere into the drinking water in the well. For each of the 26 radionuclides considered, the most significant exposure pathways for hypothetical individuals were identified. For 14 of the radionuclides, the primary exposure pathways were identified as consumption of various crops and animal products following assumed agricultural use of the contaminated

  10. DOSES ASSESSMENT OF POPULATION AT LONG-TERM PERIOD AFTER THE CHERNOBYL ACCIDENT

    Directory of Open Access Journals (Sweden)

    N. G. Vlasova

    2014-01-01

    Full Text Available Republiccontaminated settlements had been developed. The results of the Whole Body measurements had been used as the basis for the model developing. The model for dose estimation is based on the classification of the settlements according to regional characteristics of soils, which cause 137Cs intake with locally produced foodstuff. The model is also based on regression of internal exposure dose on the soil surface activity for each region. The influence of the indirect factors on the dose forming had been taken into account: the number of inhabitants and the area of forest around the settlement. According  to  the  developed  method,  Catalog  of  Average  Annual  Effective  Doses  for  Residents  of  the Belarus Republic had been created.

  11. Personal radiation monitoring and assessment of doses received by radiation workers (1996)

    Energy Technology Data Exchange (ETDEWEB)

    Morris, N.D.

    1996-12-01

    Since late 1986, all persons monitored by the Australian Radiation Laboratory have been registered on a data base which maintains records of the doses received by each individual wearer. At present, the Service regularly monitors approximately 30,000 persons, which is roughly 90 percent of those monitored in Australia, and maintains dose histories of over 75,000 people. The skin dose for occupationally exposed workers can be measured by using one of the five types of monitor issued by the Service: Thermoluminescent Dosemeter (TLD monitor), Finger TLD 3, Neutron Monitor, Special TLD and Environmental monitor. The technical description of the monitors is provided along with the method for calculating the radiation dose. 5 refs., 7 tabs., 5 figs.

  12. Exposure Scenarios and Unit Dose Factors for the Hanford Immobilized Low Activity Tank Waste Performance Assessment

    Energy Technology Data Exchange (ETDEWEB)

    RITTMANN, P.D.

    1999-12-29

    Exposure scenarios are defined to identify potential pathways and combinations of pathways that could lead to radiation exposure from immobilized tank waste. Appropriate data and models are selected to permit calculation of dose factors for each exposure

  13. Percutaneous radiofrequency ablation for lung tumors beneath the rib under CT fluoroscopic guidance with gantry tilt

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Takanobu; Yamagami, Takuji; Tanaka, Osamu; Yoshimatsu, Rika; Miura, Hiroshi; Nishimura, Tsunehiko (Dept. of Radiology, Graduate School of Medical Science, Kyoto Prefectural Univ. of Medicine, Kamigyo, Kyoto (Japan)), e-mail: yamagami@koto.kpu-m.ac.jp

    2010-05-15

    Background: Radiofrequency (RF) ablation of lung tumors has become a treatment of choice, especially for unresectable cases. However, RF ablation of small lung lesions located just beneath the rib is difficult. Purpose: To evaluate the efficacy and safety of gantry tilting for the performance of RF ablation of peripheral lesions located beneath the rib. Material and Methods: Our study was based on 18 of 293 lesions in the lung for which RF ablation was performed under CT scan fluoroscopic guidance at our institution between October 2004 and March 2009. For these 18 lesions, RF ablation was performed with gantry tilting because a rib blocked visualization of the RF ablation route even after other attempts had been made to change the relationship between the target and the rib. Results: All RF needles, with only one exception, were successfully advanced to hit the tumor. The commonest complication was a pneumothorax, which occurred in seven procedures. No serious complications occurred. The progression-free rates were 82.4% at 6 months, 62.5% at 12 months, and 30% at 24 months. Mean local progression-free duration was 17.6+-11.6 months (range 4-36 months). Conclusion: RF ablation under CT scan fluoroscopic guidance with gantry tilt is a useful and safe technique for RF ablation of lung nodules located beneath the rib

  14. A C-arm calibration method with application to fluoroscopic image-guided procedures

    Science.gov (United States)

    Rai, Lav; Gibbs, Jason D.; Wibowo, Henky

    2012-02-01

    C-arm fluoroscopy units provide continuously updating X-ray video images during surgical procedure. The modality is widely adopted for its low cost, real-time imaging capabilities, and its ability to display radio-opaque tools in the anatomy. It is, however, important to correct for fluoroscopic image distortion and estimate camera parameters, such as focal length and camera center, for registration with 3D CT scans in fluoroscopic imageguided procedures. This paper describes a method for C-arm calibration and evaluates its accuracy in multiple C-arm units and in different viewing orientations. The proposed calibration method employs a commerciallyavailable unit to track the C-arm and a calibration plate. The method estimates both the internal calibration parameters and the transformation between the coordinate systems of tracker and C-arm. The method was successfully tested on two C-arm units (GE OEC 9800 and GE OEC 9800 Plus) of different image intensifier sizes and verified with a rigid airway phantom model. The mean distortion-model error was found to be 0.14 mm and 0.17 mm for the respective C-arms. The mean overall system reprojection error (which measures the accuracy of predicting an image using tracker coordinates) was found to be 0.63 mm for the GE OEC 9800.

  15. An Assessment of Spinal Cord Dose Following Radiotherapy of Nasopharyngeal Cancer by TLD and Rando Phantom

    Directory of Open Access Journals (Sweden)

    Mohammad Taghi Bahreyni Toossi

    2009-12-01

    Full Text Available Introduction: Nasopharyngeal carcinoma is one of the most common malignancies in the head and neck region and radiotherapy is its treatment of choice. In spite of the fact that it is widely used, due to the presence of many sensitive organs or tissues in this region, patients may suffer from a wide range of side effects. One such sensitive tissue is the spinal cord. If the absorbed dose to spinal cord is greater than its tolerance dose, then myelopathy and Lhermitte’s sign are not avoidable. Material and Methods: Thehead and neck of a Rando phantom (reference man was employed as a hypothetical patient suffering from nasopharyngeal carcinoma. The full course of treatment consisted of three phases. At the beginning of every phase, an oncologist used a simulator to delineate the surface of the Rando Phantom for treatment. TLD chips (TLD-100 were employed for dose measurement. TLD chips were inserted in the previously made holes on the surface of selected slices adjacent to second cervical to fourth thoracic vertebra. Absorbed dose by TLDs were read by a Harshaw 3500 TLD reader. Results: Total measured dose (in Gy of various parts of spinal cord adjacent to second cervical to fourth thoracic vertebra varied widely and were as follows respectively: 15.24±1.31, 50.31±1.06, 49.15±2.77, 47.48±1.42, 54.56±2.6, 48.92±0.6, 45.1±0.45. In other words, the range of doses received by different segments of the spinal cord could be as wide as 15.24 to 54.56 Gy. Conclusion: Although the spinal cord was excluded at the end of the first phase, a significant change in the absorbed dose at the end of the first and second phases was not observed. In phase three, the anterior neck field was replaced by a lateral field and the spinal cord absorbed dose was reduced considerably. According to our results, absorbed doses of the spinal cord segments corresponding to the region confined between the third cervical to third thoracic vertebra were more than the 47 Gy

  16. Preliminary assessment of radiological doses in alternative waste management systems without an MRS facility

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, K.J.; Pelto, P.J.; Daling, P.M.; Lavender, J.C.; Fecht, B.A.

    1986-06-01

    This report presents generic analyses of radiological dose impacts of nine hypothetical changes in the operation of a waste management system without a monitored retrievable storage (MRS) facility. The waste management activities examined in this study include those for handling commercial spent fuel at nuclear power reactors and at the surface facilities of a deep geologic repository, and the transportation of spent fuel by rail and truck between the reactors and the repository. In the reference study system, the radiological doses to the public and to the occupational workers are low, about 170 person-rem/1000 metric ton of uranium (MTU) handled with 70% of the fuel transported by rail and 30% by truck. The radiological doses to the public are almost entirely from transportation, whereas the doses to the occupational workers are highest at the reactors and the repository. Operating alternatives examined included using larger transportation casks, marshaling rail cars into multicar dedicated trains, consolidating spent fuel at the reactors, and wet or dry transfer options of spent fuel from dry storage casks. The largest contribution to radiological doses per unit of spent fuel for both the public and occupational workers would result from use of truck transportation casks, which are smaller than rail casks. Thus, reducing the number of shipments by increasing cask sizes and capacities (which also would reduce the number of casks to be handled at the terminals) would reduce the radiological doses in all cases. Consolidating spent fuel at the reactors would reduce the radiological doses to the public but would increase the doses to the occupational workers at the reactors.

  17. Radiation Dose Assessments for Shore-Based Individuals in Operation Tomodachi

    Science.gov (United States)

    2012-09-30

    Misawa AB Kyoto Kyoto Iwate Morioka City of Ofunato* Osaka Osaka Miyagi Sendai Camp Sendai* Hyogo Kobe Akita Akita Nara Nara Yamagata Yamagata... economy one day per week for the first month (a total of 4 days), the highest doses would have been calculated for a 1-year old child yielding values...Radiation dose estimates to people who were living solely on the local economy near U.S. military installations should be comparable to the values in

  18. Dynamic dose assessment by Large Eddy Simulation of the near-range atmospheric dispersion.

    Science.gov (United States)

    Vervecken, Lieven; Camps, Johan; Meyers, Johan

    2015-03-01

    In order to improve the simulation of the near-range atmospheric dispersion of radionuclides, computational fluid dynamics is becoming increasingly popular. In the current study, Large-Eddy Simulation is used to examine the time-evolution of the turbulent dispersion of radioactive gases in the atmospheric boundary layer, and it is coupled to a gamma dose rate model that is based on the point-kernel method with buildup factors. In this way, the variability of radiological dose rate from cloud shine due to instantaneous turbulent mixing processes can be evaluated. The steady release in an open field of (41)Ar and (133)Xe for 4 different release heights is studied, thus covering radionuclides that decay with a high-energy gamma and a low-energy gamma, respectively. Based on these simulations, the variability of dose rates at ground level for different averaging times in the dose measurements is analyzed. It is observed that turbulent variability in the wind field can lead to dose estimates that are underestimated by up to a factor of four when conventional long-term measurements are used to estimate the dose from short-term exposures.

  19. Assessment of patient dose and radiogenic risks during endoscopic retrograde cholangiopancreatography

    Energy Technology Data Exchange (ETDEWEB)

    Sulieman, A.; Elzaki, M. [Sudan University of Science and Technology, College of Medical Radiologic Science, P. O. Box 1908, Khartoum 11111 (Sudan); Alkhorayef, M.; Babikir, E. [King Saud University, College of Applied Sciences, Radiological Sciences Department, P. O. Box 10219, Riyadh 11433 (Saudi Arabia); Abuzaid, M. [University of Sharjah, College of Health Sciences, Medical Diagnostic Imaging Department, Sharjah (United Arab Emirates); Dalton, A.; Bradley, D., E-mail: Abdelmoneim_a@yahoo.com [University of Surrey, Centre for Nuclear and Radiation Physics, Department of Physics, GU2-7XH, Guildford, Surrey (United Kingdom)

    2015-10-15

    Endoscopic retrograde cholangiopancreatography (ERCP) is an invasive technique that has been used for over 30 years in the diagnosis and management of pancreaticobiliary disorders. The objectives of this study were to evaluate the patient entrance surface air kerma doses (ESAK) and estimate the organ and effective doses during ERCP in three hospitals in Khartoum. A total of 55 patients were examined in three hospitals in Khartoum state, Sudan. Calibrated thermoluminescence dosimeters (TLD)-Gr-200-A)) were used to measure patients ESAK. The overall mean of ESAK for all ERCP procedures was 42.4 mGy. The mean patient ESAK in Fedail, Soba and Ibn sena centers were 26.7 mGy, 26.0 mGy, 72.4 mGy, respectively. The effective doses in three centers were 1.6, 1.56 and 2.67 mSv in that order and the overall mean effective dose was 2.01 mSv. Patient radiation doses vary widely among the different hospitals. Patient ESAK is low compared to previous studies in the light of the current practice. Patient dose was decreased significantly in the last two decades. (Author)

  20. Dual-resolution dose assessments for proton beamlet using MCNPX 2.6.0

    Science.gov (United States)

    Chao, T. C.; Wei, S. C.; Wu, S. W.; Tung, C. J.; Tu, S. J.; Cheng, H. W.; Lee, C. C.

    2015-11-01

    The purpose of this study is to access proton dose distribution in dual resolution phantoms using MCNPX 2.6.0. The dual resolution phantom uses higher resolution in Bragg peak, area near large dose gradient, or heterogeneous interface and lower resolution in the rest. MCNPX 2.6.0 was installed in Ubuntu 10.04 with MPI for parallel computing. FMesh1 tallies were utilized to record the energy deposition which is a special designed tally for voxel phantoms that converts dose deposition from fluence. 60 and 120 MeV narrow proton beam were incident into Coarse, Dual and Fine resolution phantoms with pure water, water-bone-water and water-air-water setups. The doses in coarse resolution phantoms are underestimated owing to partial volume effect. The dose distributions in dual or high resolution phantoms agreed well with each other and dual resolution phantoms were at least 10 times more efficient than fine resolution one. Because the secondary particle range is much longer in air than in water, the dose of low density region may be under-estimated if the resolution or calculation grid is not small enough.

  1. ASSESSMENT OF UNCERTAINTY IN THE RADIATION DOSES FOR THE TECHA RIVER DOSIMETRY SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Napier, Bruce A.; Degteva, M. O.; Anspaugh, L. R.; Shagina, N. B.

    2009-10-23

    In order to provide more accurate and precise estimates of individual dose (and thus more precise estimates of radiation risk) for the members of the ETRC, a new dosimetric calculation system, the Techa River Dosimetry System-2009 (TRDS-2009) has been prepared. The deterministic version of the improved dosimetry system TRDS-2009D was basically completed in April 2009. Recent developments in evaluation of dose-response models in light of uncertain dose have highlighted the importance of different types of uncertainties in the development of individual dose estimates. These include uncertain parameters that may be either shared or unshared within the dosimetric cohort, and also the nature of the type of uncertainty as aleatory or epistemic and either classical or Berkson. This report identifies the nature of the various input parameters and calculational methods incorporated in the Techa River Dosimetry System (based on the TRDS-2009D implementation), with the intention of preparing a stochastic version to estimate the uncertainties in the dose estimates. This report reviews the equations, databases, and input parameters, and then identifies the author’s interpretations of their general nature. It presents the approach selected so that the stochastic, Monte-Carlo, implementation of the dosimetry System - TRDS-2009MC - will provide useful information regarding the uncertainties of the doses.

  2. Summary of the JCO criticality accident in Tokai-mura and a dose assessment.

    Science.gov (United States)

    Tanaka, S I

    2001-09-01

    A criticality accident occurred on September 30, 1999, in a conversion test facility at the JCO Tokai site. The accident was triggered by pouring an 18.8% enriched uranyl nitrate solution into a precipitation vessel beyond the critical mass. The accident continued for about 19 hours before the criticality could be stopped. during which time neutrons and gamma-rays were emitted continuously due to fission reactions. The total number of fission reactions was 2.5 x 10(18), which was estimated by an activity analysis of the fission products in the solution of the precipitation vessel. The accident gave serious radiation dose to 3 employees and fatal dose to 2 of them. Neutrons and gamma-rays emitted by the accident caused meaningful doses to the residents of the surrounding area of JCO. The dominant dose to the residents and JCO employees was brought by neutrons and gamma-rays from the precipitation vessel, while the contribution of radioactive plume was negligible. The individual dose was estimated for 234 resident, 169 JCO employees and 260 emergency personnel. The maximum doses were 21 mSv for the residents, 48mSv for the JCO employees, and 9.4mSv for the emergency personnel, respectively. No deterministic effect, however, has been observed, except for the 3 workers.

  3. DOSE ASSESSMENT OF THE FINAL INVENTORIES IN CENTER SLIT TRENCHES ONE THROUGH FIVE

    Energy Technology Data Exchange (ETDEWEB)

    Collard, L.; Hamm, L.; Smith, F.

    2011-05-02

    In response to a request from Solid Waste Management (SWM), this study evaluates the performance of waste disposed in Slit Trenches 1-5 by calculating exposure doses and concentrations. As of 8/19/2010, Slit Trenches 1-5 have been filled and are closed to future waste disposal in support of an ARRA-funded interim operational cover project. Slit Trenches 6 and 7 are currently in operation and are not addressed within this analysis. Their current inventory limits are based on the 2008 SA and are not being impacted by this study. This analysis considers the location and the timing of waste disposal in Slit Trenches 1-5 throughout their operational life. In addition, the following improvements to the modeling approach have been incorporated into this analysis: (1) Final waste inventories from WITS are used for the base case analysis where variance in the reported final disposal inventories is addressed through a sensitivity analysis; (2) Updated K{sub d} values are used; (3) Area percentages of non-crushable containers are used in the analysis to determine expected infiltration flows for cases that consider collapse of these containers; (4) An updated representation of ETF carbon column vessels disposed in SLIT3-Unit F is used. Preliminary analyses indicated a problem meeting the groundwater beta-gamma dose limit because of high H-3 and I-129 release from the ETF vessels. The updated model uses results from a recent structural analysis of the ETF vessels indicating that water does not penetrate the vessels for about 130 years and that the vessels remain structurally intact throughout the 1130-year period of assessment; and (5) Operational covers are included with revised installation dates and sets of Slit Trenches that have a common cover. With the exception of the modeling enhancements noted above, the analysis follows the same methodology used in the 2008 PA (WSRC, 2008) and the 2008 SA (Collard and Hamm, 2008). Infiltration flows through the vadose zone are

  4. Accurate dose assessment system for an exposed person utilising radiation transport calculation codes in emergency response to a radiological accident.

    Science.gov (United States)

    Takahashi, F; Shigemori, Y; Seki, A

    2009-01-01

    A system has been developed to assess radiation dose distribution inside the body of exposed persons in a radiological accident by utilising radiation transport calculation codes-MCNP and MCNPX. The system consists mainly of two parts, pre-processor and post-processor of the radiation transport calculation. Programs for the pre-processor are used to set up a 'problem-dependent' input file, which defines the accident condition and dosimetric quantities to be estimated. The program developed for the post-processor part can effectively indicate dose information based upon the output file of the code. All of the programs in the dosimetry system can be executed with a generally used personal computer and accurately give the dose profile to an exposed person in a radiological accident without complicated procedures. An experiment using a physical phantom was carried out to verify the availability of the dosimetry system with the developed programs in a gamma ray irradiation field.

  5. SU-E-I-26: Estimation of Micro-Angiographic Fluoroscope (MAF) Gain Settings for Digital Subtraction Angiography (DSA) Based on the Fluoroscopic Exposure.

    Science.gov (United States)

    Ionita, C; Loughran, B; Nagesh, S Setlur; Jain, A; Bednarek, D; Rudin, S

    2012-06-01

    The MAF is a new high-resolution detector which is being clinically evaluated in neuro-vascular procedures. The detector contains a large-dynamic-range, high-sensitivity light image intensifier with variable gain. Since the MAF is a research prototype only partially integrated with the clinical system, x-ray technique parameters must be set manually. To improve workflow we developed an automatic method to estimate and set the proper LII voltage (MAF gain) for DSA acquisition based on the fluoroscopic parameters. The detector entrance exposure (XD) can be written as the x-ray tube output exposure (Xo) times an object attenuation factor and an inverse-square correction. If the object attenuation, scatter and distances are unchanged and the effect of x-ray kVp changes are neglected, then the DSA XD can be expressed as the ratio of Xo(DSA)/Xo(Fluoroscopy) multiplied with XD(fluoroscopy). We measured Xo for fluoroscopy and DSA for mAs and kVp ranges appropriate to neuro- vascular interventions and fit the data with a 2D function. To estimate the XD(Fluoroscopy) we derived a curve of XD versus LII-voltage for a mid- dynamic-range average pixel gray-level. Since the MAF system during clinical fluoroscopy automatically adjusts the LII voltage until the desired gray-level value is achieved, by reading that voltage we can estimate the XD(Fluoroscopy). Using the 2D-fit function, Xo(DSA) is automatically calculated for the kVp and mA values set and XD(DSA) can be estimated using the relation above. Using the inverse LII calibration curve, the proper LII-voltage can be determined for the desired average gray-level. The algorithm was implemented and evaluated in thirty-two in-vivo DSA runs on rabbits. The proper LII voltage was selected in all cases with no failures. Using the fluoroscopic LII gain setting to determine the appropriate DSA setting can greatly improve the workflow in clinical evaluations of the MAF. NIH Grants R01-EB008425, R01-EB002873 and an equipment grant from

  6. Assessment of infant dose through milk in a lactating woman taking amisulpride and desvenlafaxine for treatment-resistant depression.

    Science.gov (United States)

    Ilett, Kenneth F; Watt, Felice; Hackett, L Peter; Kohan, Rolland; Teoh, Stephanie

    2010-12-01

    This study presents the case of a 35-year-old breastfeeding mother who delivered her fourth child 5 months previously and was prescribed 100 mg amisulpride twice daily and 250 mg desvenlafaxine in the morning for treatment-resistant depression. Arriving at this regimen took approximately 2 months postbirth. Because she was keen to continue breastfeeding her infant, and published data on the use of amisulpride and desvenlafaxine were very limited, the clinical team sought assistance from the therapeutic drug monitoring laboratory to quantify infant dose-exposure to guide consideration of continuing breastfeeding. A sampling schedule for milk and plasma from mother and plasma from her infant was agreed and drug concentrations were measured by high-performance liquid chromatography. Absolute (theoretic) infant dose (μg/kg/d) was calculated as the product of the average concentration in milk and an assumed milk intake of 0.15 L/kg/day (294 mg/kg/day for desvenlafaxine and 183 mg/kg/day for amisulpride), and relative infant dose was estimated as absolute infant dose expressed as a percentage of the maternal dose in μg/kg/day (7.8% for desvenlafaxine and 6.1% for amisulpride). Consistent with the infant being partially breastfed, the ratio of drug in the infant's plasma to that in mother's plasma was lower at 1.7% for desvenlafaxine and 3.9% for amisulpride. A pediatric assessment of the infant found achievement of expected developmental progress for age and no detectable drug-related adverse effects. Assessing the safety of breastfeeding was difficult because it involved simultaneous use of two drugs for which there was limited previous experience. However, after discussion of the infant dose-exposure data and lack of adverse effects, the mother elected to continue partial breastfeeding for the next few months. The clinical team plans a reassessment of the infant's progress in 3 months.

  7. A Probabilistic Approach to Assess External Doses to the Public Considering Spatial Variability of Radioactive Contamination and Interpopulation Differences in Behavior Pattern.

    Science.gov (United States)

    Takahara, Shogo; Iijima, Masashi; Yoneda, Minoru; Shimada, Yoko

    2017-09-08

    Dose assessment is an important issue from the viewpoints of protecting people from radiation exposure and managing postaccident situations adequately. However, the radiation doses received by people cannot be determined with complete accuracy because of the uncertainties and the variability associated with any process of defining individual characteristics and in the dose assessment process itself. In this study, a dose assessment model was developed based on measurements and surveys of individual doses and relevant contributors (i.e., ambient dose rates and behavior patterns) in Fukushima City for four population groups: Fukushima City Office staff, Senior Citizens' Club, Contractors' Association, and Agricultural Cooperative. In addition, probabilistic assessments were performed for these population groups by considering the spatial variability of contamination and interpopulation differences resulting from behavior patterns. As a result of comparison with the actual measurements, the assessment results for participants from the Fukushima City Office agreed with the measured values, thereby validating the model and the approach. Although the assessment results obtained for the Senior Citizens' Club and the Agricultural Cooperative differ partly from the measured values, by addressing further considerations in terms of dose reduction effects due to decontamination and the impact of additional exposure sources in agricultural fields, these results can be improved. By contrast, the measurements obtained for the participants from the Contractors' Association were not reproduced well in the present study. To assess the doses to this group, further investigations of association members' work activities and the related dose reduction effects are needed. © 2017 Society for Risk Analysis.

  8. Assessing patient dose in interventional fluoroscopy using patient-dependent hybrid phantoms

    Science.gov (United States)

    Johnson, Perry Barnett

    Interventional fluoroscopy uses ionizing radiation to guide small instruments through blood vessels or other body pathways to sites of clinical interest. The technique represents a tremendous advantage over invasive surgical procedures, as it requires only a small incision, thus reducing the risk of infection and providing for shorter recovery times. The growing use and increasing complexity of interventional procedures, however, has resulted in public health concerns regarding radiation exposures, particularly with respect to localized skin dose. Tracking and documenting patient-specific skin and internal organ dose has been specifically identified for interventional fluoroscopy where extended irradiation times, multiple projections, and repeat procedures can lead to some of the largest doses encountered in radiology. Furthermore, inprocedure knowledge of localized skin doses can be of significant clinical importance to managing patient risk and in training radiology residents. In this dissertation, a framework is presented for monitoring the radiation dose delivered to patients undergoing interventional procedures. The framework is built around two key points, developing better anthropomorphic models, and designing clinically relevant software systems for dose estimation. To begin, a library of 50 hybrid patient-dependent computational phantoms was developed based on the UF hybrid male and female reference phantoms. These phantoms represent a different type of anthropomorphic model whereby anthropometric parameters from an individual patient are used during phantom selection. The patient-dependent library was first validated and then used in two patient-phantom matching studies focused on cumulative organ and local skin dose. In terms of organ dose, patient-phantom matching was shown most beneficial for estimating the dose to large patients where error associated with soft tissue attenuation differences could be minimized. For small patients, inherent difference

  9. Assessment of the radiological impact of gamma and radon dose rates at former U mining sites in Tajikistan.

    Science.gov (United States)

    Lespukh, E; Stegnar, P; Yunusov, M; Tilloboev, H; Zyazev, G; Kayukov, P; Hosseini, A; Strømman, G; Salbu, B

    2013-12-01

    An assessment of the radiological situation due to exposure to gamma radiation, radon ((222)Rn) and thoron ((220)Rn) was carried out at former uranium (U) mining and processing sites in Taboshar and at Digmai in Tajikistan. Gamma dose rate measurements were made using various field instruments. (222)Rn/(220)Rn measurements were carried out with field instruments for instantaneous measurements and then discriminative (222)Rn/(220)Rn solid state nuclear track detectors (SSNTD) were used for longer representative measurements. The detectors were exposed for an extended period of time in different outdoor and indoor public and residential environments at the selected U legacy sites. The results showed that gamma, (222)Rn and (220)Rn doses were in general low, which consequently implies a low to relatively low radiological risk. The radiation doses deriving from external radiation (gamma dose rate), indoor (222)Rn and (220)Rn with their short-lived progenies did not exceed national or international standards. At none of the sites investigated did the average individual annual effective doses exceed 10 mSv, the recommended threshold value for the general public. A radiation hazard could be associated with exceptional situations, such as elevated exposures to ionizing radiation at the Digmai tailings site and/or in industrial facilities, where gamma and (222)Rn/(220)Rn dose rates could reach values of several 10 mSv/a. Current doses of ionizing radiation do not represent a hazard to the health of the resident public, with the exception of some specific situations. These issues should be adequately addressed to further reduce needless exposure of the resident public to ionizing radiation.

  10. Assessment of target volume doses in radiotherapy based on the standard and measured calibration curves

    Directory of Open Access Journals (Sweden)

    Gholamreza Fallah Mohammadi

    2015-01-01

    Full Text Available Context: In radiation treatments, estimation of the dose distribution in the target volume is one of the main components of the treatment planning procedure. To estimate the dose distribution, the information of electron densities is necessary. The standard curves determined by computed tomography (CT scanner that may be different from that of other oncology centers. In this study, the changes of dose calculation due to the different calibration curves (HU-ρel were investigated. Materials and Methods: Dose values were calculated based on the standard calibration curve that was predefined for the treatment planning system (TPS. The calibration curve was also extracted from the CT images of the phantom, and dose values were calculated based on this curve. The percentage errors of the calculated values were determined. Statistical Analysis Used: The statistical analyses of the mean differences were performed using the Wilcoxon rank-sum test for both of the calibration curves. Results and Discussion: The results show no significant difference for both of the measured and standard calibration curves (HU-ρel in 6, 15, and 18 MeV energies. In Wilcoxon ranked sum nonparametric test for independent samples with P < 0.05, the equality of monitor units for both of the curves to transfer 200 cGy doses to reference points was resulted. The percentage errors of the calculated values were lower than 2% and 1.5% in 6 and 15 MeV, respectively. Conclusion: From the results, it could be concluded that the standard calibration curve could be used in TPS dose calculation accurately.

  11. Assessment of ocular beta radiation dose distribution due to 106Ru/106Rh brachytherapy applicators using MCNPX Monte Carlo code

    Directory of Open Access Journals (Sweden)

    Nilseia Aparecida Barbosa

    2014-08-01

    heterogeneous eye model, indicating that the homogeneous water eye model is a reasonable one. The determined isodose curves give a good visualization of dose distributions inside the eye structures, pointing out their most exposed volume....................................................Cite this article as:Barbosa NA, da Rosa LAR, de Menezes AF, Reis JP, Facure A, Braz D. Assessment of ocular beta radiation dose distribution due to 106Ru/106Rh brachytherapy applicators using MCNPX Monte Carlo code. Int J Cancer Ther Oncol 2014; 2(3:02038. DOI: 10.14319/ijcto.0203.8

  12. Generation of dose-response relationships to assess the effects of acidity in precipitation on growth and productivity of vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Evans, L.S.

    1981-01-01

    Experiments were performed with several plant species in natural environments as well in a greenhouse and/or tissue culture facilities to establish dose-response functions of plant responses to simulated acidic rain in order to determine environmental risk assessments to ambient levels of acidic rain. Response functions of foliar injury, biomass of leaves and seed of soybean and pinto beans, root yields of radishes and garden beets, and reproduction of bracken fern are considered. The dose-response function of soybean seed yields with the hydrogen ion concentration of simulated acidic rainfalls was expressed by the equation y = 21.06-1.01 log x where y = seed yield in grams per plant and x = the hydrogen concentration if ..mu..eq l/sup -1/. The correlation coefficient of this relationship was -0.90. A similar dose-response function was generated for percent fertilization of ferns in a forest understory. When percent fertilization is plotted on logarithmic scale with hydrogen ion concentration of the simulated rain solution, the Y intercept is 51.18, slope -0.041 with a correlation coefficient of -0.98. Other dose-response functions were generated that assist in a general knowledge as to which plant species and which physiological processes are most impacted by acidic precipitation. Some responses did not produce convenient dose-response relationships. In such cases the responses may be altered by other environmental factors or there may be no differences among treatment means.

  13. Flattening filter free beams in SBRT and IMRT. Dosimetric assessment of peripheral doses

    Energy Technology Data Exchange (ETDEWEB)

    Kragl, Gabriele; Baier, Franziska; Albrich, David; Kroupa, Bernhard; Georg, Dietmar [Medical Univ. of Vienna/AKH Vienna (Austria). Dept. of Radiotherapy; Lutz, Steffen; Wiezorek, Tilo [University Hospital Jena (Germany). Dept. of Radiotherapy; Dalaryd, Maarten; Knoeoes, Tommy [Lund Univ. (Sweden). Radiation Physics; Skaane Univ. Hospital (Sweden). Radiation Physics

    2011-07-01

    Purpose: Recently, there has been a growing interest in operating medical linear accelerators without a flattening filter. Due to reduced scatter, leaf transmission and radiation head leakage a reduction of out-of-field dose is expected for flattening filter free beams. The aim of the present study was to determine the impact of unflattened beams on peripheral dose for advanced treatment techniques with a large number of MUs. Material and methods: An Elekta Precise linac was modified to provide 6 and 10 MV photon beams without a flattening filter. Basic beam data were collected and implemented into the TPS Oncentra Masterplan (Nucletron). Leakage radiation, which predominantly contributes to peripheral dose at larger distances from the field edge, was measured using a Farmer type ionisation chamber. SBRT (lung) and IMRT (prostate, head and neck) treatment plans were generated for 6 and 10 MV for both flattened and unflattened beams. All treatment plans were delivered to the relevant anatomic region of an anthropomorphic phantom which was extended by a solid water slab phantom. Dosimetric measurements were performed with TLD-700 rods, radiochromic films and a Farmer type ionisation chamber. The detectors were placed within the slab phantom and positioned along the isocentric longitudinal axis. Results: Using unflattened beams results in a reduction of treatment head leakage by 52% for 6 and 65% for 10 MV. Thus, peripheral doses were in general smaller for treatment plans calculated with unflattened beams. At about 20 cm distance from the field edge the dose was on average reduced by 23 and 31% for the 6 and 10 MV SBRT plans. For the IMRT plans (10 MV) the average reduction was 16% for the prostate and 18% for the head and neck case, respectively. For all examined cases, the relative deviation between peripheral doses of flattened and unflattened beams was found to increase with increasing distance from the field. Conclusions: Removing the flattening filter lead to

  14. Assessing pharmacokinetics of different doses of fosfomycin in laboratory rats enables adequate exposure for pharmacodynamic models.

    Science.gov (United States)

    Poeppl, Wolfgang; Lingscheid, Tilman; Bernitzky, Dominik; Donath, Oliver; Reznicek, Gottfried; Zeitlinger, Markus; Burgmann, Heinz

    2014-01-01

    Fosfomycin has been the subject of numerous pharmacodynamic in vivo models in recent years. The present study set out to determine fosfomycin pharmacokinetics in laboratory rats to enable adequate dosing regimens in future rodent models. Fosfomycin was given intraperitoneally as single doses of 75, 200 and 500 mg/kg bodyweight to 4 Sprague-Dawley rats per dose group. Blood samples were collected over 8 h and fosfomycin concentrations were determined by HPLC-mass spectrometry. Fosfomycin showed a dose-proportional pharmacokinetic profile indicated by a correlation of 0.99 for maximum concentration and area under the concentration-time curve (AUC). The mean AUC0-8 after intraperitoneal administration of 75, 200 or 500 mg/kg bodyweight fosfomycin were 109.4, 387.0 and 829.1 µg·h/ml, respectively. In conclusion, a dosing regimen of 200-500 mg/kg 3 times daily is appropriate to obtain serum concentrations in laboratory rats, closely mimicking human serum concentrations over time.

  15. Assessment of dose in thyroid and salivary glands in dental radiology using thermoluminescent dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Mantuano, Natalia de O.; Silva, Ademir X. da [Instituto Alberto Luiz Coimbra de Pos-Graduacao e Pesquisa em Engenharia (PEN/COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Nuclear; Canevaro, Luca V.; Mauricio, Claudia Lucia P. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ) Rio de Janeiro, RJ (Brazil); Correa, Samanda C.A., E-mail: scorrea@cnen.gov.b [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    Radiobiological and epidemiological studies have provided evidence of risk of salivary and thyroid glands tumors incidence associated with oral radiology. Based on these studies, the tissue weighting factors were reviewed by the International Commission on Radiological Protection (ICRP) in 2007. The main objective of the present work is to estimate the absorbed dose on thyroid and salivary glands (parotid, submandibular and sublingual), during a complete periapical examination. The complete periapical examination was simulated using a Spectro 70X Seletronic X-ray dental equipment on an Alderson Rando phantom with Harshaw LiF:Mg,Ti thermoluminescent dosemeters (TLD100). A PTW DIADOS dosimetric system was used for calibration. The TLD100 were inserted into the phantom slices corresponding to the organs of interest. During a complete periapical examination, the highest evaluated mean absorbed dose was 4.9 mGy in the right submandibular gland and the lowest one of 1.5 mGy in the left thyroid lobe. Entrance surface doses ranged from 2.1 to 2.6 mGy, measured, respectively, for the techniques of upper left molar and lower right molar. When compared with the diagnostic reference levels (DRL), the entrance surface doses values were lower than the DRLs recommended in Brazilian current legislation. However, the dosimetric results show the need of optimization for complete periapical examination to minimize patient exposure. Measurements were performed without the use of thyroid protectors. The use of this device is certainly an easy and simple method of dose reduction. (author)

  16. Safety assessments of subcutaneous doses of aragonite calcium carbonate nanocrystals in rats

    Science.gov (United States)

    Jaji, Alhaji Zubair; Zakaria, Zuki Abu Bakar; Mahmud, Rozi; Loqman, Mohamad Yusof; Hezmee, Mohamad Noor Mohamad; Abba, Yusuf; Isa, Tijani; Mahmood, Saffanah Khuder

    2017-05-01

    Calcium carbonate nanoparticles have shown promising potentials in the delivery of drugs and metabolites. There is however, a paucity of information on the safety of their intentional or accidental over exposures to biological systems and general health safety. To this end, this study aims at documenting information on the safety of subcutaneous doses of biogenic nanocrystals of aragonite polymorph of calcium carbonate derived from cockle shells (ANC) in Sprague-Dawley (SD) rats. ANC was synthesized using the top-down method, characterized using the transmission electron microscopy and field emission scanning electron microscope and its acute and repeated dose 28-day trial toxicities were evaluated in SD rats. The results showed that the homogenous 30 ± 5 nm-sized spherical pure aragonite nanocrystals were not associated with mortality in the rats. Severe clinical signs and gross and histopathological lesions, indicating organ toxicities, were recorded in the acute toxicity (29,500 mg/m2) group and the high dose (5900 mg/m2) group of the repeated dose 28-day trial. However, the medium- (590 mg/m2 body weight) and low (59 mg/m2)-dose groups showed moderate to mild lesions. The relatively mild lesions observed in the low toxicity dosage group marked the safety margin of ANC in SD rats. It was concluded from this study that the toxicity of CaCO3 was dependent on the particulate size (30 ± 5 nm) and concentration and the route of administration used.

  17. Biodosimetry for dose assessment of partial-body exposure: a methodological improvement

    Directory of Open Access Journals (Sweden)

    Thiago Salazar Fernandes

    2008-12-01

    Full Text Available This study has explored the possibility of combining culture times with extending the duration for which Colcemid is present in cell culture in order to obtain better dose estimations following partial-body exposures. Irradiated and unirradiated blood was mixed to simulate a partial-exposure. Dicentric frequencies and resultant dose estimations were compared from 48 and 72 h cultures with Colcemid added at the beginning, after 24 h or for the final 3 h. The frequencies of dicentrics in first division cells increased with the cell culture time, providing better dose estimations. Unwanted excessive contraction of chromosomes caused by prolonged contact with Colcemid was measured and ways to avoid this are discussed. It is suggested that the combination of a lower than usual concentration of this drug combined with its earlier addition and longer culture time may provide metaphases better suited for interpreting partial-body exposures.Este trabalho avaliou a estimativa da dose de radiação simulando uma exposição parcial do corpo através da irradiação in vitro de amostras de sangue misturadas com amostras não irradiadas. Foi observado que o prolongamento do tempo de cultura permite que a real fração de linfócitos em M1 contendo aberrações cromossômicas seja detectada, propiciando melhores estimativas de dose, sem a necessidade de correções matemáticas.

  18. Dose Assessment using Chromosome Aberration Analyses in Human Peripheral Blood Lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Tae Ho; Kim, Jin-Hong; Kim, Jin Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The healthy five donors were recruited to establish the dose-response calibration curve for chromosomal aberrations by ionizing radiation exposure. Our cytogenetic results revealed that the mean frequency of chromosome aberration increased with increasing radiation dose. In this study, dicentric assay and CBMN assay were compared considering the sensitivity and accuracy of dose estimation. Therefore, these chromosome aberration analyses will be the foundation for biological dosimetric analysis with additional research methods such as translocation and PCC assay. The conventional analysis of dicentric chromosomes in HPBL was suggested by Bender and Gooch in 1962. This assay has been for many years, the golden standard and the most specific method for ionizing radiation damage. The dicentric assay technique in HPBL has been shown as the most sensitive biological method and reliable bio-indicator of quantifying the radiation dose. In contrast, the micronucleus assay has advantages over the dicentric assay since it is rapid and requires less specialized expertise, and accordingly it can be applied to monitor a big population. The cytokinesis-block micronucleus (CBMN) assay is a suitable method for micronuceli measurement in cultured human as well as mammalian cells. The aim of our study was to establish the dose response curve of radiation-induced chromosome aberrations in HPBL by analyzing the frequency of dicentrics and micronuclei.

  19. Discrepancy between fluoroscopic arthrography and magnetic resonance arthrography in patients with arthroscopically confirmed supraspinatus tendon tears: The additional benefit of cine fluoroscopic arthrography images

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, Seok; Lee, Young Han; Suh, Jin Suck [Dept. Radiology, Research Institute of Radiological Science, Medical Convergence Research Institute, and Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2016-12-15

    To determine the additional diagnostic benefits of fluoroscopic arthrography (FA) in patients with full-thickness supraspinatus tendon (SST) tears by comparing FA images with magnetic resonance arthrography (MRA) images. This study included FA and MRA images of 53 patients who were confirmed to have full-thickness SST tears by arthroscopy. In the FA analysis, the presence of contrast leakage into the subacromial-subdeltoid bursa was recorded. In the MRA analysis, contrast leakage, retraction of a torn tendon, width and length of the tear, and supraspinatus atrophy were evaluated. Patients were divided into the concordant group or the discordant group based on the presence of contrast leakage to compare the characteristics of SST tears. We used Fisher's exact test and two-sample t-test for the comparison. Of the 53 patients, 34 were included in the concordant group and 19 were included in the discordant group. In the concordant group, the grades of retraction were higher than those in the discordant group; the width and length of the tears were larger. Muscle atrophy was more severe in the concordant group. A full-thickness SST tear did not always exhibit contrast leakage on FA, particularly small SST tears or tears with low-grade retraction. FA can provide diagnostic information regarding the severity of full-thickness SST tears by itself.

  20. Radiological-dose assessments of atolls in the northern Marshall Islands

    Energy Technology Data Exchange (ETDEWEB)

    Robison, W.L.

    1983-04-01

    The Marshall Islands in the Equatorial Pacific, specifically Enewetak and Bikini Atolls, were the site of US nuclear testing from 1946 through 1958. In 1978, the Northern Marshall Islands Radiological Survey was conducted to evaluate the radiological conditions of two islands and ten atolls downwind of the proving grounds. The survey included aerial external gamma measurements and collection of soil, terrestrial, and marine samples for radionuclide analysis to determine the radiological dose from all exposure pathways. The methods and models used to estimate doses to a population in an environment where natural processes have acted on the source-term radionuclides for nearly 30 y, data bases developed for the models, and results of the radiological dose analyses are described.

  1. Assessment of potential radiation dose rates to marine organisms around the Korean Peninsula

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Myung [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Lee, Jun Ho [University of Science and Technology, Daejeon (Korea, Republic of)

    2016-05-15

    It is very difficult to set a regulatory guidance or criteria for the protection of non-human species from the ionizing radiation, because there are no generally or internationally accepted methods for demonstrating the compliance with such criteria. It is needed that Korea develop the primary dose rate standards for the protection of both aquatic and terrestrial biota in the near future. The potential dose rates due to both external and internal radiation exposures to marine organisms such as plaice/flounder, gray mullet, and brown seaweed collected within territorial seas around the Korean Peninsula were estimated. The total dose rates to plaice/flounder, gray mullet and brown seaweed due to {sup 40}K, a primordial radionuclide in marine environment, were found to be 0.2%, 0.08% and 0.3% of approximately the values of the Derived Consideration Reference Levels (DCRLs, i.e. 1-10 mGy d{sup -1}), respectively, as suggested by the International Commission on Radiological Protection (ICRP) publication 124. The total dose rates to marine fishes and brown seaweed due to anthropogenic radionuclides such as {sup 90}Sr, {sup 137}Cs and {sup 239+240}Pu were considered to be negligible compared to the total dose rate due to {sup 40}K. The external exposure to benthic fish due to all radionuclides was much higher than that of pelagic fish. From this study, it is recommended that the further study is required to develop a national regulatory guidance for the evaluation of doses to non-human species.

  2. Routine Use of Fluoroscopic-Guided Femoral Arterial Puncture to Minimise Vascular Complication Rates in CTO Intervention: Multi-centre UK Experience.

    Science.gov (United States)

    Fairley, Sarah L; Lucking, Andrew J; McEntegart, Margaret; Shaukat, Aadil; Smith, David; Chase, Alexander; Hanratty, Colm G; Spratt, James C; Walsh, Simon J

    2016-12-01

    Chronic total occlusion (CTO) revascularisation has a crucial role in contemporary percutaneous coronary intervention (PCI). Procedural success is influenced by disease complexity, calcific burden and patient characteristics but has substantially improved with the implementation of novel hybrid strategies. However, vascular-access related complications remain a cause of morbidity and mortality. This study aimed to assess the effectiveness of fluoroscopic-guided femoral arterial puncture to minimise this risk during CTO PCI. Standardised data were retrospectively collected from four high-volume UK CTO centres between September 2011 and November 2013. Demographic, clinical and procedural data (vascular access site, sheath size, anticoagulation use) was collated. The anatomical location of the femoral puncture in relation to the femoral bifurcation, femoral head position and inferior epigastric artery were recorded. Adverse events related to vascular access were documented. A total of 528 patients were included (676 femoral punctures) with the majority being male (n=432, 81.8%). Large sheaths (8F) were used in 81.2% of cases. Fluoroscopy-enabled punctures were made in the 'safe zone' in over > 93% of cases. Vascular closure devices (VCD) were used in 88.3% of cases. The adverse event rate per puncture was 0.89%. This study demonstrates an extremely low incidence of vascular-access complications in CTO PCI when fluoroscopic guidance is used to obtain femoral arterial access by default radial operators. Copyright © 2016 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  3. Dose assessment from domestic building materials used in housing sector in Serbia.

    Science.gov (United States)

    Petrović, M; Vučić, D; Karamarković, J

    2014-11-01

    The results of mass activity measuring in many domestic building materials used in a housing sector are presented. Natural radionuclides (40)K, (226)Ra, (232)Th, (235)U and (238)U as well as artificial radionuclide (137)Cs were detected using a gamma spectrometry. Based on measured mass activity values, the absorbed dose rate from examined building materials was calculated following EC standards. According to the UNSCEAR procedure, the annual effective dose was also calculated. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. Image-guided transapical aortic valve implantation: sensorless tracking of stenotic valve landmarks in live fluoroscopic images.

    Science.gov (United States)

    Merk, Denis R; Karar, Mohamed Esmail; Chalopin, Claire; Holzhey, David; Falk, Volkmar; Mohr, Friedrich W; Burgert, Oliver

    2011-07-01

    Aortic valve stenosis is one of the most frequently acquired valvular heart diseases, accounting for almost 70% of valvular cardiac surgery. Transapical transcatheter aortic valve implantation has recently become a suitable minimally invasive technique for high-risk and elderly patients with severe aortic stenosis. In this article, we aim to automatically define a target area of valve implantation, namely, the area between the coronary ostia and the lowest points of two aortic valve cusps. Therefore, we present a new image-based tracking method of these aortic landmarks to assist in the placement of aortic valve prosthesis under live 2D fluoroscopy guidance. We propose a rigid intensity-based image registration technique for tracking valve landmarks in 2D fluoroscopic image sequences, based on a real-time alignment of a contrast image including the initialized manual valve landmarks to each image of sequence. The contrast image is automatically detected to visualize aortic valve features when the aortic root is filled with a contrast agent. Our registration-based tracking method has been retrospectively applied to 10 fluoroscopic image sequences from routine transapical aortic valve implantation procedures. Most of all tested fluoroscopic images showed a successful tracking of valve landmarks, especially for the images without contrast agent injections. A new intraoperative image-based method has been developed for tracking aortic valve landmarks in live 2D fluoroscopic images to assist transapical aortic valve implantations and to increase the overall safety of surgery as well.

  5. Fluoroscopic-guided covered metallic stent placement for gastric outlet obstruction and post-operative gastroenterostomy anastomotic stricture

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Min; Han, Young Min; Kim, Chong Soo; Lee, Sang Young; Lee, Soo Teik; Yang, Doo Hyun

    2001-07-01

    AIM: To evaluate the feasibility and safety of fluoroscopic-guided covered metallic stent placements in providing palliative care for patients with inoperable malignant gastric outlet obstruction. MATERIALS AND METHODS: Under fluoroscopic guidance, placement of self-expandable, covered stents was attempted in 20 patients with inoperable or recurrent gastric cancer (age range 36-79 years). All patients had inoperable gastric outlet obstruction, 13 with native anatomy and seven with post-operative anatomy (gastrointestinal anastomotic sites). All patients had intolerance to oral alimentation and/or vomiting after ingestion. Success was defined both technically and clinically. RESULTS: The placement of the stent was technically successful in 18 patients and failed in two patients (technical success: 90%). The cause of the technical failures was an inability to negotiate the guide wire through the obstruction sites in spite of the use of both fluoroscopic and endoscopic guidance. After stent placement, 15 patients were able to ingest at least liquids and had a markedly decreased incidence of vomiting (clinical success: 75%). During the mean follow-up of 6 weeks, there have been no stent reocclusion and no life-threatening complications except migration of two stents in one patient. CONCLUSION: Fluoroscopically guided covered metallic stent placement appears to be valuable for the palliative treatment of malignant obstruction of gastric outlet and post-operative gastrointestinal anastomoses. Lee, J.M. et al. (2001)

  6. Assessing the risk of birth defects associated with exposure to fixed-dose combined antituberculous agents during pregnancy in rats.

    Science.gov (United States)

    Awodele, O; Patrick, E B; Oluwatoyin Agbaje, Esther; Oremosu, A A; Gbotolorun, S C

    2012-01-01

    Due to the risks of disease progression and transmission to the newborn, treatment of tuberculosis is often pursued during pregnancy and fixed-dose combined antituberculous agents have been found to be beneficial. Unfortunately, there is paucity of data on the safety of the fixed-dose combined antituberculous drugs during pregnancy. This study intends to assess the teratogenic effect of fixed-dose combined antituberculous drugs on the organogenesis stage of fetal development and also investigate the possible roles of vitamin C in modulating the teratogenic effects of these agents on the fetus using animal model. Pregnant rats were divided into 3 groups with 12 animals per group: group 1 received distilled water (10 mL/kg) orally; group 2 received 51.4 mg/kg/day of fixed-dose combined antituberculous agents orally; group 3 received 51.4 mg/kg/day of fixed-dose combined antituberculous agents plus vitamin C (10 mg/kg/day) orally. Six rats in each group were randomly selected and sacrificed on day 20 by cervical dislocation prior to day 21 of gestation, and the foetuses were harvested through abdominal incision for physical examination. Blood samples were collected from the 1st filial rats of the remaining six animals for biochemical and hematological examination. The liver, kidney, heart, and brain of all the sacrificed animals were used for histopathological examination. There were significant (P ≤ 0.05) low birth weights of the foetuses of the animals that were treated with fixed-dose combined antituberculous agents. The haematological parameters also revealed a reduction in the platelets counts and neutrophiles at the first filial generation. Significant (P ≤ 0.05) elevations in the levels of aspartate aminotransferase (AST) and alkaline phosphatase (ALP) in the foetuses of the animals treated with fixed-dose combined antituberculous agents were also observed. However, the combination of vitamin C with fixed-dose combined antituberculous agents significantly

  7. Assessing the Risk of Birth Defects Associated with Exposure to Fixed-Dose Combined Antituberculous Agents during Pregnancy in Rats

    Directory of Open Access Journals (Sweden)

    O. Awodele

    2012-01-01

    Full Text Available Due to the risks of disease progression and transmission to the newborn, treatment of tuberculosis is often pursued during pregnancy and fixed-dose combined antituberculous agents have been found to be beneficial. Unfortunately, there is paucity of data on the safety of the fixed-dose combined antituberculous drugs during pregnancy. This study intends to assess the teratogenic effect of fixed-dose combined antituberculous drugs on the organogenesis stage of fetal development and also investigate the possible roles of vitamin C in modulating the teratogenic effects of these agents on the fetus using animal model. Pregnant rats were divided into 3 groups with 12 animals per group: group 1 received distilled water (10 mL/kg orally; group 2 received 51.4 mg/kg/day of fixed-dose combined antituberculous agents orally; group 3 received 51.4 mg/kg/day of fixed-dose combined antituberculous agents plus vitamin C (10 mg/kg/day orally. Six rats in each group were randomly selected and sacrificed on day 20 by cervical dislocation prior to day 21 of gestation, and the foetuses were harvested through abdominal incision for physical examination. Blood samples were collected from the 1st filial rats of the remaining six animals for biochemical and hematological examination. The liver, kidney, heart, and brain of all the sacrificed animals were used for histopathological examination. There were significant (≤0.05 low birth weights of the foetuses of the animals that were treated with fixed-dose combined antituberculous agents. The haematological parameters also revealed a reduction in the platelets counts and neutrophiles at the first filial generation. Significant (≤0.05 elevations in the levels of aspartate aminotransferase (AST and alkaline phosphatase (ALP in the foetuses of the animals treated with fixed-dose combined antituberculous agents were also observed. However, the combination of vitamin C with fixed-dose combined antituberculous agents

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

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Tianwu [Geneva University Hospital, Division of Nuclear Medicine and Molecular Imaging, Geneva (Switzerland); Zaidi, Habib [Geneva University Hospital, Division of Nuclear Medicine and Molecular Imaging, Geneva (Switzerland); Geneva University, Geneva Neuroscience Center, Geneva (Switzerland); University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); University of Southern Denmark, Department of Nuclear Medicine, Odense (Denmark)

    2016-12-15

    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 {sup 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. (orig.)

  9. Influence of radiation dose and reconstruction algorithm in MDCT assessment of airway wall thickness: A phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Cardona, Daniel [Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Nagle, Scott K. [Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Avenue, Madison, Wisconsin 53792 (United States); Department of Pediatrics, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Avenue, Madison, Wisconsin 53792 (United States); Li, Ke; Chen, Guang-Hong, E-mail: gchen7@wisc.edu [Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Avenue, Madison, Wisconsin 53792 (United States); Robinson, Terry E. [Department of Pediatrics, Stanford School of Medicine, 770 Welch Road, Palo Alto, California 94304 (United States)

    2015-10-15

    Purpose: Wall thickness (WT) is an airway feature of great interest for the assessment of morphological changes in the lung parenchyma. Multidetector computed tomography (MDCT) has recently been used to evaluate airway WT, but the potential risk of radiation-induced carcinogenesis—particularly in younger patients—might limit a wider use of this imaging method in clinical practice. The recent commercial implementation of the statistical model-based iterative reconstruction (MBIR) algorithm, instead of the conventional filtered back projection (FBP) algorithm, has enabled considerable radiation dose reduction in many other clinical applications of MDCT. The purpose of this work was to study the impact of radiation dose and MBIR in the MDCT assessment of airway WT. Methods: An airway phantom was scanned using a clinical MDCT system (Discovery CT750 HD, GE Healthcare) at 4 kV levels and 5 mAs levels. Both FBP and a commercial implementation of MBIR (Veo{sup TM}, GE Healthcare) were used to reconstruct CT images of the airways. For each kV–mAs combination and each reconstruction algorithm, the contrast-to-noise ratio (CNR) of the airways was measured, and the WT of each airway was measured and compared with the nominal value; the relative bias and the angular standard deviation in the measured WT were calculated. For each airway and reconstruction algorithm, the overall performance of WT quantification across all of the 20 kV–mAs combinations was quantified by the sum of squares (SSQs) of the difference between the measured and nominal WT values. Finally, the particular kV–mAs combination and reconstruction algorithm that minimized radiation dose while still achieving a reference WT quantification accuracy level was chosen as the optimal acquisition and reconstruction settings. Results: The wall thicknesses of seven airways of different sizes were analyzed in the study. Compared with FBP, MBIR improved the CNR of the airways, particularly at low radiation dose

  10. Fluoroscopically Guided Three-Tube Insertion for the Treatment of Postoperative Gastroesophageal Anastomotic Leakage

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Guowen; Xu, Qingyu; Chen, Shixi; Bai, Xiangjun; Jiang, Feng; Zhang, Qin; Xu, Lin; Xu, Weidong [Cancer Hospital of Jiangsu Province, Nanjing (Korea, Republic of)

    2012-03-15

    To retrospectively evaluate the feasibility and effectiveness of three-tube insertion for the treatment of postoperative gastroesophageal anastomotic leakage (GEAL). From January 2007 to January 2011, 28 cases of postoperative GEAL after an esophagectomy with intrathoracic esophagogastric anastomotic procedures for esophageal and cardiac carcinoma were treated by the insertion of three tubes under fluoroscopic guidance. The three tubes consisted of a drainage tube through the leak, a nasogastric decompression tube, and a nasojejunum feeding tube. The study population consisted of 28 patients (18 males, 10 females) ranging in their ages from 36 to 72 years (mean: 59 years). We evaluated the feasibility of three-tube insertion to facilitate leakage site closure, and the patients' nutritional benefit by checking their serum albumin levels between pre- and post-enteral feeding via the feeding tube. The three tubes were successfully placed under fluoroscopic guidance in all twenty-eight patients (100%). The procedure times for the three tube insertion ranged from 30 to 70 minutes (mean time: 45 minutes). In 27 of 28 patients (96%), leakage site closure after three-tube insertion was achieved, while it was not attained in one patient who received stent implantation as a substitute. All patients showed good tolerance of the three-tube insertion in the nasal cavity. The mean time needed for leakage treatment was 21 {+-} 3.5 days. The serum albumin level change was significant, increasing from pre-enteral feeding (2.5 {+-} 0.40 g/dL) to post-enteral feeding (3.7 {+-} 0.51 g/dL) via the feeding tube (p < 0.001). The duration of follow-up ranged from 7 to 60 months (mean: 28 months). Based on the results of this study, the insertion of three tubes under fluoroscopic guidance is safe, and also provides effective relief from postesophagectomy GEAL. Moreover, our findings suggest that three-tube insertion may be used as the primary procedure to treat postoperative GEAL.

  11. Diagnostic assessment to estimate and minimize neutron dose rates received by occupationally exposed individuals at cyclotron facilities

    Energy Technology Data Exchange (ETDEWEB)

    Reina, L.C. [Instituto de Engenharia Nuclear, Comissao Nacional de Energia Nuclear, Caixa Postal 68550, Cidade Universitaria, CEP: 21941-906 Rio de Janeiro (Brazil)], E-mail: reina@ien.gov.br; Silva, A.X. [PEN/COPPE-DNC/Escola Politecnica, Universidade Federal do Rio de Janeiro, Cidade Universitaria, CEP: 21945-970 Rio de Janeiro (Brazil); Suita, J.C.; Souza, M.I.S. [Instituto de Engenharia Nuclear, Comissao Nacional de Energia Nuclear, Caixa Postal 68550, Cidade Universitaria, CEP: 21941-906 Rio de Janeiro (Brazil); Facure, A. [Comissao Nacional de Energia Nuclear Rua General Severiano, 90-Botafogo, CEP: 22290-901 Rio de Janeiro (Brazil); Silva, J.C.P.; Furlanetto, J.A.D. [Instituto de Engenharia Nuclear, Comissao Nacional de Energia Nuclear, Caixa Postal 68550, Cidade Universitaria, CEP: 21941-906 Rio de Janeiro (Brazil); Rebello, W. [Instituto Militar de Engenharia, Ministerio da Defesa Praca General Tiburcio, 80-Praia Vermelha, CEP: 22290-270 Rio de Janeiro (Brazil)

    2010-03-15

    Since 2003, radiopharmaceuticals for medical diagnostic purposes have been produced at the Instituto de Engenharia Nuclear, in Brazil, using two cyclotron accelerators - CV-28 and RDS111. As a result of the ever increasing production, a diagnostic assessment to reduce neutron dose rates received by occupationally exposed individuals during irradiation processes has been developed. The purpose of this work is to present this assessment, which is currently being applied to both the Fluorine and Iodine targets of CV-28 and RDS111 cyclotron accelerators.

  12. Determination of 210Po concentration in commercially available infant formulae and assessment of daily ingestion dose

    Directory of Open Access Journals (Sweden)

    Ravi K. Prabhath

    2015-07-01

    Full Text Available A study has been conducted to estimate the concentration of natural radioactive polonium in commercially available packaged infant food formulae available in Mumbai, India and the corresponding daily dose normalized based on its shelf life. Eleven most popular international brands of infant formulae were sourced from market and three aliquots from each sample were analysed for concordant results. Autodeposition method onto a silver planchet from hot dilute acid solution followed by alpha spectrometry was performed for estimation of polonium. Radiochemical recovery was ascertained by the addition of 209Po tracer. Radiochemical recovery of 209Po tracer was ranged from 14.7 to 98.1 %. The 210Po concentration in the samples was in the range of 0.08–0.23 Bq kg−1 on measured date and the corresponding daily dose, calculated on normalized date which is at mid-point of the shelf life of the sample, was ranged from 0.04 to 0.89 μSv d−1 as per the recommended daily consumption. The annual committed effective dose estimated based on the average of daily dose was found to be 150 μSv.

  13. Assessment of brain dose distribution for ARC and conformal radiation therapy (CRT: A comparison study

    Directory of Open Access Journals (Sweden)

    Tamer Dawod

    2015-01-01

    Conclusion: The tangential beam ARCRT planning demonstrated a significantly better homogeneity index for the GTV, CTV, and PTV of the brain cancer patients with a significant reduction in the mean doses of the both eyes, optic nerves, optic chiasm and brain stem.

  14. Dose assessment to inhalation exposure of indoor 222Rn daughters in Korea.

    Science.gov (United States)

    Ha, C W; Chang, S Y; Lee, B H

    1992-10-01

    Long-term, average indoor 222Rn concentrations were measured in 12 residential areas by passive CR-39 radon cups. Corresponding equilibrium-equivalent concentration of radon daughters were derived. The resulting effective dose equivalent for the Korean population due to inhalation exposure of this equilibrium-equivalent concentration of radon daughters was then evaluated.

  15. Shielding design and dose assessment for accelerator based neutron capture therapy.

    Science.gov (United States)

    Howard, W B; Yanch, J C

    1995-05-01

    Preparations are ongoing to test the viability and usefulness of an accelerator source of epithermal neutrons for ultimate use in a clinical environment. This feasibility study is to be conducted in a shielded room located on the Massachusetts Institute of Technology campus and will not involve patient irradiations. The accelerator production of neutrons is based on the 7Li(p, n)7Be reaction, and a maximum proton beam current of 4 mA at an energy of 2.5 MeV is anticipated. The resultant 3.58 x 10(12) neutrons s-1 have a maximum energy of 800 keV and will be substantially moderated. This paper describes the Monte Carlo methods used to estimate the neutron and photon dose rates in a variety of locations in the vicinity of the accelerator, as well as the shielding configuration required when the device is run at maximum current. Results indicate that the highest absorbed dose rate to which any individual will be exposed is 3 microSv h-1 (0.3 mrem h-1). The highest possible yearly dose is 0.2 microSv (2 x 10(-2) mrem) to the general public or 0.9 mSv (90 mrem) to a radiation worker in close proximity to the accelerator facility. The shielding necessary to achieve these dose levels is also discussed.

  16. A Probabilistic Approach to Uncertainty Analysis in NTPR Radiation Dose Assessments

    Science.gov (United States)

    2009-11-01

    Headquarters (HQ) Detachment, Enewetak Atoll .............................................. 115 5.1.1 Case Description and Cohort Participation Scenario...Administrative and Operations Detachments, Enewetak Atoll .......................... 122 5.2.1 Case Description and Cohort Participation Scenario...Figure 33. Comparison of the Dose Distribution from Probabilistic Analysis with Unbiased Film Badge Readings for the 7126th AU at Enewetak Atoll

  17. DOSE ASSESSMENTS FROM THE DISPOSAL OF LOW-ACTIVITY WASTES IN RCRA-C DISPOSAL CELLS

    Science.gov (United States)

    Modeling the long-term performance of the RCRA-C disposal cell and potential doses to off-site receptors is used to derive maximum radionuclide specific concentrations in the wastes that would enable these wastes to be disposed of safely using the RCRA-C disposal cell technology....

  18. Assessment of {sup 226}Ra age-dependent dose from water intake

    Energy Technology Data Exchange (ETDEWEB)

    Porntepkasemsan, Boonsom [Research and Development Group, Thailand Institute of Nuclear Technology, Vibhavadi Rangsit Road, Bangkok 10900 (Thailand)], E-mail: boonsom@oaep.go.th; Srisuksawad, Kanitha [Research and Development Group, Thailand Institute of Nuclear Technology, Vibhavadi Rangsit Road, Bangkok 10900 (Thailand)

    2008-11-15

    The radioactivity in canal and ground waters collected in a 2-year long observation from the vicinity of the Rare Earth Research and Development Center (RRDC), Phathumthani Province, Thailand, was measured in order to determine the concentration of {sup 226}Ra and to estimate the age-dependent effective dose to humans due to consumption. {sup 226}Ra activities in both canal and ground waters were well below the WHO guidance level for drinking water quality of 1 Bq L{sup -1}. The highest {sup 226}Ra effective doses per year were found for infants and teens. However, the observed levels of calculated {sup 226}Ra effective doses for all age groups in both canal and ground waters show satisfactory low values (less than 15 {mu}Sv yr{sup -1}). These values are acceptable in accordance with the WHO recommended reference dose level of 100 {mu}Sv yr{sup -1} from water intake of 2 L day{sup -1}.

  19. Development of Internal Dose Assessment Program for Nuclear Power Plant Employees

    Energy Technology Data Exchange (ETDEWEB)

    Song, Myung Jae; Kang, Duck Won; Maeng, Sung Jun; Kim, Hee Geun; Son, Soon Whan; Lim, Young Kee; Son, Joong Kwon; Park, Keyoung Rock [Korea Electric Power Research Institute, Taejon (Korea, Republic of); Jang, See Young; Ha, Jong Woo; Suh, Keyoung Won [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Oh, Oak Doo; Lee, Joong Woo; Yoon, Sung Sik [Yonsei University, Seoul (Korea, Republic of)

    1996-12-31

    Internal exposure monitoring based on new concept of radiation protection. Analysis and Performance test of the in vivo systems being operated in nuclear power plants in Korea. Design and fabrication of humanoid phantom for calibration of in vivo system. Development of internal dose evaluation code based on the ICRP 30 dosimetric model. (author). 44 refs., figs.

  20. How to assess success of treatment when using multiple doses: the case of misoprostol for medical abortion.

    Science.gov (United States)

    Seuc, Armando H; Shah, Iqbal H; Ali, Moazzam; Diaz-Olavarrieta, Claudia; Temmerman, Marleen

    2015-11-07

    The assessment of treatment success in clinical trials when multiple (repeated) doses (courses) are involved is quite common, for example, in the case of infertility treatment with assisted reproductive technology (ART), and medical abortion using misoprostol alone or in combination with mifepristone. Under these or similar circumstances, most researchers assess success using binomial proportions after a certain number of consecutive doses, and some have used survival analysis. In this paper we discuss the main problems in using binomial proportions to summarize (the overall) efficacy after two or more consecutive doses of the relevant treatment, particularly for the case of misoprostol in medical abortion studies. We later discuss why the survival analysis is best suited under these circumstances, and illustrate this by using simulated data. The formulas required for the binomial proportion and survival analysis (without and with competing risks) approaches are summarized and analytically compared. Additionally, numerical results are computed and compared between the two approaches, for several theoretical scenarios. The main conceptual limitations of the binomial proportion approach are identified and discussed, caused mainly by the presence of censoring and competing risks, and it is demonstrated how survival analysis can solve these problems. In general, the binomial proportion approach tends to underestimate the "real" success rate, and tends to overestimate the corresponding standard error. Depending on the rates of censored observations or competing events between repeated doses of the treatment, the bias of the binomial proportion approach as compared to the survival analysis approaches varies; however, the use of the binomial approach is unjustified as the survival analysis options are well known and available in multiple statistical packages. Our conclusions also apply to other situations where success is estimated after multiple (repeated) doses (courses

  1. Bone mineral density assessment using the EOS low-dose X-ray device: a feasibility study.

    Science.gov (United States)

    Sapin, E; Briot, K; Kolta, S; Gravel, P; Skalli, W; Roux, C; Mitton, D

    2008-11-01

    To predict bone strength in the case of osteoporosis, it could be a real benefit to assess the three-dimensional (3D) geometry and the bone mineral density (BMD) with a single low-dose X-ray device, such as the EOS system (Biospace Med, Paris, France). EOS 3D reconstructions of the spine have already been validated. Thus, this study aims at evaluating the accuracy of this low-dose system as a densitometer first ex vivo. The European Spine Phantom (ESP) (number 129) was scanned ten times using both the EOS and a Hologic device (Hologic, Inc., Massachusetts, USA). Accuracy was given by the sum of the systematic error (difference between BMDs assessed and true values given by the phantom manufacturer) and the random error (coefficient of variation). EOS BMDs and Hologic BMDs of 41 ex-vivo vertebrae were calculated and compared. The reproducibility of the method evaluating the EOS BMD was assessed giving the coefficient of variation of three measurements of the 41 vertebrae. The accuracy of the EOS system is below 5.2 per cent, versus 7.2 per cent for the Hologic system in the same conditions. EOS BMDs are significantly higher than Hologic BMDs, but they are strongly correlated. The reproducibility of the method of assessment is equal to 0.95 per cent. The EOS system is accurate for ex-vivo BMD assessments, which is promising regarding the use of this new system to predict vertebral strength.

  2. Assessment of doses caused by electrons in thin layers of tissue-equivalent materials, using MCNP.

    Science.gov (United States)

    Heide, Bernd

    2013-10-01

    Absorbed doses caused by electron irradiation were calculated with Monte Carlo N-Particle transport code (MCNP) for thin layers of tissue-equivalent materials. The layers were so thin that the calculation of energy deposition was on the border of the scope of MCNP. Therefore, in this article application of three different methods of calculation of energy deposition is discussed. This was done by means of two scenarios: in the first one, electrons were emitted from the centre of a sphere of water and also recorded in that sphere; and in the second, an irradiation with the PTB Secondary Standard BSS2 was modelled, where electrons were emitted from an (90)Sr/(90)Y area source and recorded inside a cuboid phantom made of tissue-equivalent material. The speed and accuracy of the different methods were of interest. While a significant difference in accuracy was visible for one method in the first scenario, the difference in accuracy of the three methods was insignificant for the second one. Considerable differences in speed were found for both scenarios. In order to demonstrate the need for calculating the dose in thin small zones, a third scenario was constructed and simulated as well. The third scenario was nearly equal to the second one, but a pike of lead was assumed to be inside the phantom in addition. A dose enhancement (caused by the pike of lead) of ∼113 % was recorded for a thin hollow cylinder at a depth of 0.007 cm, which the basal-skin layer is referred to in particular. Dose enhancements between 68 and 88 % were found for a slab with a radius of 0.09 cm for all depths. All dose enhancements were hardly noticeable for a slab with a cross-sectional area of 1 cm(2), which is usually applied to operational radiation protection.

  3. Assessment of indoor radon doses received by the students in the Azad Kashmir schools, Pakistan.

    Science.gov (United States)

    Rafique, Muhammad; Rahman, S U; Rahman, Said; Matiullah; Shahzad, M Ikram; Ahmed, Navid; Iqbal, Javid; Ahmed, Basharat; Ahmed, Tanveer; Akhtar, Nadeem

    2010-12-01

    Several epidemiological studies conducted on thousands of underground miners suggest that long- term exposure to high radon concentration can increase the risk of lung cancer. Keeping in view the importance of the subject, numerous studies throughout the world have been carried out to measure indoor radon concentration and its resulting doses at occupational and non-occupational sites. The purpose of the current study was to measure indoor radon concentration and its resulting doses received by the students of Azad Kashmir government schools. For this purpose, CR-39 radon detectors were installed in 80 carefully selected schools. The detectors were placed at a height of 3-5 ft. (depending upon average height of students in particular class) from the ground. After exposure of 90 d detectors were etched for 9 h in 6 M NaOH at 70°C and the observed track densities were related to radon concentrations. The measured indoor radon concentration ranged from 22 ± 9 to 228 ± 3 Bq m(-3) with a mean value of 78 ± 5 Bq m(-3). Based on the measured indoor radon data, the annual effective doses were found to vary from 0.55 ± 0.04 to 0.71 ± 0.03 mSv y(-1). The overall mean effective dose for the studied area was found to be 0.63 ± 0.04 mSv y(-1). Reported values for radon concentrations and corresponding doses are lower than ICRP recommended limits for workplaces.

  4. Low-dose phase-based X-ray imaging techniques for in situ soft tissue engineering assessments.

    Science.gov (United States)

    Izadifar, Zohreh; Honaramooz, Ali; Wiebe, Sheldon; Belev, George; Chen, Xiongbiao; Chapman, Dean

    2016-03-01

    In tissue engineering, non-invasive imaging of biomaterial scaffolds and tissues in living systems is essential to longitudinal animal studies for assessments without interrupting the repair process. Conventional X-ray imaging is inadequate for use in soft tissue engineering due to the limited absorption difference between the soft tissue and biomaterial scaffolds. X-ray phase-based imaging techniques that derive contrast from refraction or phase effects rather than absorption can provide the necessary contrast to see low-density biomaterial scaffolds and tissues in large living systems. This paper explores and compares three synchrotron phase-based X-ray imaging techniques-computed tomography (CT)-diffraction enhanced imaging (DEI), -analyzer based imaging (ABI), and -phase contrast imaging (PCI)-for visualization and characterization of low-density biomaterial scaffolds and tissues in situ for non-invasive soft tissue engineering assessments. Intact pig joints implanted with polycaprolactone scaffolds were used as the model to assess and compare the imaging techniques in terms of different qualitative and quantitative criteria. For long-term in vivo live animal imaging, different strategies for reducing the imaging radiation dose and scan time-reduced number of CT projections, region of interest, and low resolution imaging-were examined with the presented phase-based imaging techniques. The results demonstrated promising capabilities of the phase-based techniques for visualization of biomaterial scaffolds and soft tissues in situ. The low-dose imaging strategies were illustrated effective for reducing the radiation dose to levels appropriate for live animal imaging. The comparison among the imaging techniques suggested that CT-DEI has the highest efficiency in retaining image contrast at considerably low radiation doses.

  5. Emergency assessment of patients with acute abdominal pain using low-dose CT with iterative reconstruction: a comparative study.

    Science.gov (United States)

    Poletti, Pierre-Alexandre; Becker, Minerva; Becker, Christoph D; Halfon Poletti, Alice; Rutschmann, Olivier T; Zaidi, Habib; Perneger, Thomas; Platon, Alexandra

    2017-08-01

    To determine if radiation dose delivered by contrast-enhanced CT (CECT) for acute abdominal pain can be reduced to the dose administered in abdominal radiography (<2.5 mSv) using low-dose CT (LDCT) with iterative reconstruction algorithms. One hundred and fifty-one consecutive patients requiring CECT for acute abdominal pain were included, and their body mass index (BMI) was calculated. CECT was immediately followed by LDCT. LDCT series was processed using 1) 40% iterative reconstruction algorithm blended with filtered back projection (LDCT-IR-FBP) and 2) model-based iterative reconstruction algorithm (LDCT-MBIR). LDCT-IR-FBP and LDCT-MBIR images were reviewed independently by two board-certified radiologists (Raters 1 and 2). Abdominal pathology was revealed on CECT in 120 (79%) patients. In those with BMI <30, accuracies for correct diagnosis by Rater 1 with LDCT-IR-FBP and LDCT-MBIR, when compared to CECT, were 95.4% (104/109) and 99% (108/109), respectively, and 92.7% (101/109) and 100% (109/109) for Rater 2. In patients with BMI ≥30, accuracies with LDCT-IR-FBP and LDCT-MBIR were 88.1% (37/42) and 90.5% (38/42) for Rater 1 and 78.6% (33/42) and 92.9% (39/42) for Rater 2. The radiation dose delivered by CT to non-obese patients with acute abdominal pain can be safely reduced to levels close to standard radiography using LDCT-MBIR. • LDCT-MBIR (<2.5 mSv) can be used to assess acute abdominal pain. • LDCT-MBIR (<2.5 mSv) cannot safely assess acute abdominal pain in obese patients. • LDCT-IR-FBP (<2.5 mSv) cannot safely assess patients with acute abdominal pain.

  6. Impact of patient positioning on radiotherapy dose distribution: An assessment in parotid tumor

    Directory of Open Access Journals (Sweden)

    Seema Sharma

    2016-03-01

    Full Text Available Purpose: We intended to study the impact of patient positioning on the dose distribution within target volume and organs at risk in patients with parotid malignancies treated with 3D conformal radiotherapy (3D-CRT with photon wedge pair (WP or intensity modulated radiotherapy (IMRT.Methods: Three patients with a non-Hodgkin’s lymphoma of the right parotid gland were consecutively immobilized using thermoplastic cast in 2 positions: supine with head in neutral position (HN and with head turned 90° to the left side (HT. Images for treatment planning purpose were acquired in both positions. For both positions, photon WP plans and 5 field IMRT plans were generated, after contouring clinical target volume (CTV, planning target volume (PTV= CTV + 5 mm margin and organs at risk (OAR. All plans were evaluated for target coverage and dose to OARs.Results: Both CTV and PTV were apparently larger in HN compared with HT (31.76±8.89 cc, 30.31±7.83 cc and 62.49±19.01 cc, 58.89±15.33 cc respectively. The CI value for PTV was slightly better for HT compared to HN position in both the WP and IMRT plans. The homogeneity was comparable in both the head positions in case of WP plan. The mean HI of PTV was increased in case of IMRT plan at HT versus HN position (1.108 vs. 1.097. A change in head position from HN to HT with wedge pair plan resulted in a reduction of brainstem Dmax and Dmean. Lesser dose was observed in HN position for contralateral parotid. A difference of 0.9 Gy in the average Dmax to spinal cord was seen. The values of Dmean to mandible, oral cavity, ipsilateral and contralateral cochlea were higher in the HT position. A change in head position from HN to HT with IMRT plan resulted in a dose reduction in average Dmax to brainstem. The spinal cord Dmax increased at the HT position by 1.2 Gy. The dose to contralateral parotid and cochlea was comparable in both the positions. However, the Dmean to oral cavity was reduced at HT position. Whereas

  7. Assessment of equivalent dose on the lens in cone beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, M. V. L.; Campos, P. S. F. [Federal University of Bahia, Department of Health Sciences, Salvador (Brazil); Andrade, M. E. A. [Federal University of Pernambuco, Department of Nuclear Energy, Recife (Brazil); Soares, M. R. [Federal University of Sergipe, Department of Physics, Sao Cristovao (Brazil); Batista, W. O., E-mail: marcusradiology@gmail.com [Federal Institute of Bahia, Department of Applied Sciences, 40.301-015 Salvador (Brazil)

    2014-08-15

    The Cone Beam Computed Tomography (CBCT) is presented as a useful test method for the evaluation of craniofacial structures. Among them stands the temporomandibular joint (T MJ) imaging as complementary to clinical evaluation. It must be considered that there is no reference levels established for diagnosis of this imaging modality. In this same context, recently the limit for crystalline lens was reviewed by ICRP which set new values to the equivalent dose. The aim of this study was to evaluate the kerma at the surface of the crystalline lens in T MJ CBCT and derive the equivalent dose. It was used an anthropomorphic phantom of the head and neck (manufactured by: Radiation Support Devices, model; Rs-230) containing equivalent tissue with dimensions of a typical patient. The dosimetric measurements were obtained by using seven pairs of thermoluminescent dosimetry (TLD) dosimeters (LiF: Mg, Ti) positioned on the surface of the crystalline lens, divided into two pairs (one pair for each eye) per scanner evaluated. The tomographic images were obtained in three CBCT equipment s (Kodak 9000, Gendex GXCB 500 and i-Cat). Values of equivalent dose obtained were: 5.82 mSv (Kodak 9000); 5.38 mSv (Gendex GXCB 500) and 7.98 mSv (i-Cat). These results demonstrate that for this type of procedure the doses are below the annual limit but may vary in accordance with the scanner and the exposure factors used in the image acquisition. The Gendex GXCB500 uses larger Fov and higher kV. It results in levels close to those obtained on Kodak 9000. Larger doses are associated with the i-Cat. Another factor that rises is the repetition of examinations due to positioning errors and / or patient movement, which may exceed the annual limit established by ICRP. Although the ICRP limits are not applied to medical exposures, it is advisable to consider the sensitivity of the organ. For this reason, it is concluded that doses per T MJ procedure on CBCT are below the annual limit and may vary

  8. Assessment of annual average effective dose status in the cohort of medical staff in Lithuania during 1991-2013.

    Science.gov (United States)

    Samerdokiene, Vitalija; Mastauskas, Albinas; Atkocius, Vydmantas

    2015-12-01

    The use of radiation sources for various medical purposes is closely related to irradiation of the medical staff, which causes harmful effects to health and an increased risk of cancer. In total, 1463 medical staff who have been occupationally exposed to sources of ionising radiation (IR) had been monitored. Records with annual dose measurements (N = 19 157) were collected and regularly analysed for a 23-y period: from 01 January 1991 to 31 December 2013. The collected annual average effective dose (AAED) data have been analysed according to different socio-demographic parameters and will be used in future investigation in order to assess cancer risk among medical staff occupationally exposed to sources of IR. A thorough analysis of data extracted from medical staff's dose records allows one to conclude that the average annual effective dose of Lithuanian medical staff occupationally exposed to sources of IR was consistently decreased from 1991 (1.75 mSv) to 2013 (0.27 mSv) (p < 0.0001).

  9. Natural radioactivities in iron and nickel ores imported into Japan and the dose assessment for workers handling them.

    Science.gov (United States)

    Iwaoka, Kazuki; Tagami, Keiko; Yonehara, Hidenori

    2010-09-01

    Japan imports Fe and Ni ores from abroad for use as industrial raw materials in the manufacture of industrial products like stainless steel. Some of these ores might contain high levels of radioactivity, and then workers handling them would be exposed to radiation without being aware of it. Activity concentrations in these ores should be measured to evaluate the radiation exposure of workers. In this study, Fe and Ni ores used as industrial raw materials were collected from iron and steel companies, and the activity concentrations of the (238)U series, the (232)Th series and (40)K in these ores were determined using inductively coupled plasma mass spectrometry (ICP-MS) and gamma ray spectrometry. The activity concentrations of the (238)U series, the (232)Th series and (40)K in these ores samples were lower than the International Atomic Energy Agency (IAEA) values. The doses to workers handling these ores were estimated using methods for dose assessment given in a report by the European Commission. In each scenario, a maximum value of the annual effective dose to workers was estimated to be about 6.8 × 10(-6) Sv, which was lower than intervention exemption levels (annual dose 1.0 × 10(-3) Sv) given in International Commission on Radiological Protection (ICRP) Publication 82.

  10. Natural radioactivities in iron and nickel ores imported into Japan and the dose assessment for workers handling them

    Energy Technology Data Exchange (ETDEWEB)

    Iwaoka, Kazuki; Tagami, Keiko; Yonehara, Hidenori, E-mail: iwaoka@nirs.go.j [Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan)

    2010-09-15

    Japan imports Fe and Ni ores from abroad for use as industrial raw materials in the manufacture of industrial products like stainless steel. Some of these ores might contain high levels of radioactivity, and then workers handling them would be exposed to radiation without being aware of it. Activity concentrations in these ores should be measured to evaluate the radiation exposure of workers. In this study, Fe and Ni ores used as industrial raw materials were collected from iron and steel companies, and the activity concentrations of the {sup 238}U series, the {sup 232}Th series and {sup 40}K in these ores were determined using inductively coupled plasma mass spectrometry (ICP-MS) and gamma ray spectrometry. The activity concentrations of the {sup 238}U series, the {sup 232}Th series and {sup 40}K in these ores samples were lower than the International Atomic Energy Agency (IAEA) values. The doses to workers handling these ores were estimated using methods for dose assessment given in a report by the European Commission. In each scenario, a maximum value of the annual effective dose to workers was estimated to be about 6.8 x 10{sup -6} Sv, which was lower than intervention exemption levels (annual dose 1.0 x 10{sup -3} Sv) given in International Commission on Radiological Protection (ICRP) Publication 82. (note)

  11. The use of ESR spectroscopy for the identification and dose assessment of irradiated pink shrimp (Parapenaeus longirostris) from Turkey

    Science.gov (United States)

    Aydaş, Canan; Tepe Çam, Semra; Engin, Birol; Aydın, Talat; Polat, Mustafa

    2013-03-01

    Turkish pink shrimp (Parapenaeus longirostris) samples were studied by electron spin resonance (ESR) spectroscopy for identification and dose assessment purposes. In this work, the calcified shells of shrimps were used as a sample material. Before irradiation, all shrimp shell samples exhibit one weak ESR singlet with a g-factor of 2.0047. After irradiation, all samples exhibit two asymmetric ESR signal components centered at g-values of 2.0013 and 1.9959. The dose-response curves of the samples exposed to gamma radiations were found to be described well by a single saturation exponential function. Variation of ESR signal intensity of irradiated samples at room and-20 °C temperatures with time in a long-term showed that free radicals responsible from the ESR spectrum of shrimp shells were not stable but still detectable after 87 days. Also, the kinetic behavior of signal at g=2.0013 was studied and the additive dose method was used to evaluate the dose in the product.

  12. ASSESSMENT OF THE AVERAGE ANNUAL EFFECTIVE DOSES FOR THE INHABITANTS OF THE SETTLEMENTS LOCATED IN THE TERRITORIES CONTAMINATED DUE TO THE CHERNOBYL ACCIDENT

    Directory of Open Access Journals (Sweden)

    N. G. Vlasova

    2012-01-01

    Full Text Available Catalogue of the average annual effective exposure doses of the inhabitants of the territories contaminated due to the Chernobul accident had been developed according to the method of the assessment of the average annual effective exposure doses of the settlements inhabitants. The cost-efficacy of the use of the average annual effective dose assessment method was 250 000 USD for the current 5 years. Average annual effective dose exceeded 1 mSv/year for 191 Belarus settlements from 2613. About 50 000 persons are living in these settlements.

  13. Use of a fluoroscopic overlay to guide femoral tunnel placement during posterior cruciate ligament reconstruction.

    Science.gov (United States)

    Araujo, Paulo H; Moloney, Gele; Rincon, Gustavo; Carey, Robert; Zhang, Xudong; Harner, Christopher

    2014-11-01

    Intraoperative recognition of the local anatomy of the posterior cruciate ligament (PCL) is difficult for many surgeons, and correct positioning of the graft can be challenging. To investigate the efficacy of an overlay system based on fluoroscopic landmarks in guiding femoral tunnel placement during PCL reconstruction. Controlled laboratory study. Twenty cadaveric knees were arthroscopically prepared, and their PCL femoral insertion sites were digitized. The digitized images were co-registered to computed tomography-acquired 3-dimensional bone models. Twenty surgeons with diverse backgrounds performed simulated arthroscopic reconstruction of the anterolateral (AL) and posteromedial (PM) bundles of the PCL, first without and then with the aid of a lateral fluoroscopic image on which the position of a target insertion site based on literature data was displayed as an overlay. The surgeons were allowed to adjust tunnel placement in accordance with the displayed target position. A 3-way comparison was made of the tunnel positions placed by the surgeons, the native insertion site positions, and the literature-based positions. The overlay system was effective in helping surgeons to improve femoral tunnel placement toward the target and toward the anatomic insertion site (P 5 mm from the native insertion site. With the use of the overlay, 70% of the surgeons were overlay to guide intraoperative placement of the femoral tunnel(s) during PCL reconstruction can result in more anatomic reconstructions and therefore assist in re-creating native knee kinematics after PCL reconstruction. Intraoperative fluoroscopy is an effective, easy, and safe method for improving femoral tunnel positioning during PCL reconstruction. © 2014 The Author(s).

  14. Accurate 3D kinematic measurement of temporomandibular joint using X-ray fluoroscopic images

    Science.gov (United States)

    Yamazaki, Takaharu; Matsumoto, Akiko; Sugamoto, Kazuomi; Matsumoto, Ken; Kakimoto, Naoya; Yura, Yoshiaki

    2014-04-01

    Accurate measurement and analysis of 3D kinematics of temporomandibular joint (TMJ) is very important for assisting clinical diagnosis and treatment of prosthodontics and orthodontics, and oral surgery. This study presents a new 3D kinematic measurement technique of the TMJ using X-ray fluoroscopic images, which can easily obtain the TMJ kinematic data in natural motion. In vivo kinematics of the TMJ (maxilla and mandibular bone) is determined using a feature-based 2D/3D registration, which uses beads silhouette on fluoroscopic images and 3D surface bone models with beads. The 3D surface models of maxilla and mandibular bone with beads were created from CT scans data of the subject using the mouthpiece with the seven strategically placed beads. In order to validate the accuracy of pose estimation for the maxilla and mandibular bone, computer simulation test was performed using five patterns of synthetic tantalum beads silhouette images. In the clinical applications, dynamic movement during jaw opening and closing was conducted, and the relative pose of the mandibular bone with respect to the maxilla bone was determined. The results of computer simulation test showed that the root mean square errors were sufficiently smaller than 1.0 mm and 1.0 degree. In the results of clinical application, during jaw opening from 0.0 to 36.8 degree of rotation, mandibular condyle exhibited 19.8 mm of anterior sliding relative to maxillary articular fossa, and these measurement values were clinically similar to the previous reports. Consequently, present technique was thought to be suitable for the 3D TMJ kinematic analysis.

  15. Efficient segmentation of 3D fluoroscopic datasets from mobile C-arm

    Science.gov (United States)

    Styner, Martin A.; Talib, Haydar; Singh, Digvijay; Nolte, Lutz-Peter

    2004-05-01

    The emerging mobile fluoroscopic 3D technology linked with a navigation system combines the advantages of CT-based and C-arm-based navigation. The intra-operative, automatic segmentation of 3D fluoroscopy datasets enables the combined visualization of surgical instruments and anatomical structures for enhanced planning, surgical eye-navigation and landmark digitization. We performed a thorough evaluation of several segmentation algorithms using a large set of data from different anatomical regions and man-made phantom objects. The analyzed segmentation methods include automatic thresholding, morphological operations, an adapted region growing method and an implicit 3D geodesic snake method. In regard to computational efficiency, all methods performed within acceptable limits on a standard Desktop PC (30sec-5min). In general, the best results were obtained with datasets from long bones, followed by extremities. The segmentations of spine, pelvis and shoulder datasets were generally of poorer quality. As expected, the threshold-based methods produced the worst results. The combined thresholding and morphological operations methods were considered appropriate for a smaller set of clean images. The region growing method performed generally much better in regard to computational efficiency and segmentation correctness, especially for datasets of joints, and lumbar and cervical spine regions. The less efficient implicit snake method was able to additionally remove wrongly segmented skin tissue regions. This study presents a step towards efficient intra-operative segmentation of 3D fluoroscopy datasets, but there is room for improvement. Next, we plan to study model-based approaches for datasets from the knee and hip joint region, which would be thenceforth applied to all anatomical regions in our continuing development of an ideal segmentation procedure for 3D fluoroscopic images.

  16. Absorbed dose assessment in particle-beam irradiated metal-oxide and metal-nonmetal memristors

    Directory of Open Access Journals (Sweden)

    Knežević Ivan D.

    2012-01-01

    Full Text Available Absorbed dose was estimated after Monte Carlo simulation of proton and ion beam irradiation on metal-oxide and metal-nonmetal memristors. A memristive device comprises two electrodes, each of a nanoscale width, and a double-layer active region disposed between and in electrical contact with electrodes. Following materials were considered for the active region: titanium dioxide, zirconium dioxide, hafnium dioxide, strontium titanium trioxide and galium nitride. Obtained results show that significant amount of oxygen ion - oxygen and nonmetal ion - nonmetal vacancy pairs is to be generated. The loss of such vacancies from the device is believed to deteriorate the device performance over time. Estimated absorbed dose values in the memristor for different constituting materials are of the same order of magnitude because of the close values of treshold displacement energies for the investigated materials.

  17. A collimated detection system for assessing leakage dose from medical linear accelerators at the patient plane.

    Science.gov (United States)

    Lonski, P; Taylor, M L; Franich, R D; Kron, T

    2014-03-01

    Leakage radiation from linear accelerators can make a significant contribution to healthy tissue dose in patients undergoing radiotherapy. In this work thermoluminescent dosimeters (LiF:Mg,Cu,P TLD chips) were used in a focused lead cone loaded with TLD chips for the purpose of evaluating leakage dose at the patient plane. By placing the TLDs at one end of a stereotactic cone, a focused measurement device is created; this was tested both in and out of the primary beam of a Varian 21-iX linac using 6 MV photons. Acrylic build up material of 1.2 cm thickness was used inside the cone and measurements made with either one or three TLD chips at a given distance from the target. Comparing the readings of three dosimeters in one plane inside the cone offered information regarding the orientation of the cone relative to a radiation source. Measurements in the patient plane with the linac gantry at various angles demonstrated that leakage dose was approximately 0.01% of the primary beam out of field when the cone was pointed directly towards the target and 0.0025% elsewhere (due to scatter within the gantry). No specific 'hot spots' (e.g., insufficient shielding or gaps at abutments) were observed. Focused cone measurements facilitate leakage dose measurements from the linac head directly at the patient plane and allow one to infer the fraction of leakage due to 'direct' photons (along the ray-path from the bremsstrahlung target) and that due to scattered photons.

  18. Radiation Dose Assessments for Fleet-Based Individuals in Operation Tomodachi, Revision 1

    Science.gov (United States)

    2014-04-01

    ships were not included in this report. In other cases, some ships were included despite being located outside the 200 nautical-mile (nmi) radius ...was included although it was well outside the 200 nmi radius from FDNPS during the two-month time period. The Seventh Fleet comprises 60–70 ships...the cosmic 37 radiation dose. Although these detection systems respond to the combined influence of all sources listed above, from the plots some

  19. Radiation Dose Assessments for Fleet-Based Individuals in Operation Tomodachi

    Science.gov (United States)

    2013-09-01

    report. In other cases, some ships were included despite being located outside the 200 nautical-mile (nmi) radius from the FDNPS because the OTR...well outside the 200 nmi radius from FDNPS during the two-month time period. The Seventh Fleet comprises 60–70 ships, 200–300 aircraft, and 40,000 Navy...surfaces. As discussed in the shore-based report, the MEXT systems did not quantify most of the cosmic radiation dose. Although these detection

  20. Assessment of Concentration and the Annual Effective Dose of Radon Gas in Imam Hospital Indoor Air

    Directory of Open Access Journals (Sweden)

    Kobra Verijkazemi

    2016-09-01

    Full Text Available Introduction and purpose: Exposure to natural sources of radiation, especially radon and its short-term products, is an important issue around the world. Radon exposure causes lung cancer in humans. Therefore, the aim of this study was to measure the concentration of radon gas and its annual effective dose in Imam Hospital of Tehran, Iran and to compare its concentrations with the recommended standards. Methods: Radon levels and meteorological parameters (temperature, pressure, and moisture were measured in different levels and in four seasons, using Radstar and Lutron Electronic devices, respectively, during June 2014-June 2015. The collected data were analyzed through SPSS 18. Annual effective dose was calculated, using the equation for annual effective dose introduced by Scientific Committee of the United Nations. Results: The highest concentration of radon and annual effective dose were observed in the winter, which were 82/15 Bq/m3 and0/48 ms/y, respectively. Furthermore, concerning the various levels, the highest concentration was observed in the lowest level (56/1 Bq/m3.Conclusion: The results of the current study demonstrated that radon concentration was lower than the standards set by Environmental Protection Agency and World Health Organization. Regarding this, there are not concerns about the possible dangers of radon gas activities for the personnel and patients of the hospital. 

  1. Radiation Dose Assessments for the Embryo, Fetus, and Nursing Infant during Operation Tomodachi

    Science.gov (United States)

    2013-08-01

    of breastfeeding by artificially choosing an effective intake time before or after the actual intake time (ICRP, 2004). However, because the total...milk; (3) used the DCs for the three month old infant for the entire nursing period; and, (4) assumed six months of breastfeeding starting at zero...weaning. The ICRP DCs, despite being based on a six-month duration of breastfeeding , can be used for estimating the doses from longer or shorter periods

  2. Radiation Dose Assessments for Shore-Based Individuals in Operation Tomodachi, Revision 1

    Science.gov (United States)

    2012-12-31

    Prefecture City Shore Location Hokkaido Sapporo Shiga Otsu Aomori Aomori Misawa AB Kyoto Kyoto Iwate Morioka City of Ofunato* Osaka Osaka Miyagi Sendai...unlikely to have consumed food and water from non-DOD sources (i.e., by eating on the local economy near their assigned locations in Japan...purposes, eating on the local economy one day per week for the first month (a total of 4 days), the highest doses would have been calculated for a 1

  3. Radiometric modeling through the combined use of the EDR gamma scanner and the VISIPLAN dose assessment tool

    Energy Technology Data Exchange (ETDEWEB)

    Perez, J.M. [Laboratoria General de Electronica y Automatica, CIEMAT, Edificio 22, Avenida Complutense 22, E-28040 Madrid (Spain)]. E-mail: jm.perez@ciemat.es; Vermeersch, F. [SCK-CEN, Boeretang 200, 2400 Mol (Belgium); Vela, O. [Laboratoria General de Electronica y Automatica, CIEMAT, Edificio 22, Avenida Complutense 22, E-28040 Madrid (Spain); Burgos, E. de [Laboratoria General de Electronica y Automatica, CIEMAT, Edificio 22, Avenida Complutense 22, E-28040 Madrid (Spain)

    2004-11-11

    In this paper, we present the work performed on the integration of a new gamma scanner prototype, known as EDR, with a 3D-dose assessment software tool called VISIPLAN. It is one of the first approaches to merge gamma imaging instrumentation and a 3D-dose assessment program into a combined operative hardware-software solution for the characterization of a site in the field of radiation protection. The main features of the scanner design are presented here, together with a representative part of the tests performed during its characterization. The EDR directional sensitivity is determined for two gamma radiation fields originating from {sup 137}Cs and {sup 60}Co sources and forms the basis for the interpretation of the gamma scans using VISIPLAN. The combination of a 3D-source model and the detailed instrument response function can determine the source activities from the gamma scans, and also enables in a second step, the simulation of the dose-rate field on the site. The integration of the two tools was tested in a laboratory and validated in an industrial facility.

  4. Assessment of knowledge and awareness among radiology personnel regarding current computed tomography technology and radiation dose

    Science.gov (United States)

    Karim, M. K. A.; Hashim, S.; Bradley, D. A.; Bahruddin, N. A.; Ang, W. C.; Salehhon, N.

    2016-03-01

    In this paper, we evaluate the level of knowledge and awareness among 120 radiology personnel working in 7 public hospitals in Johor, Malaysia, concerning Computed Tomography (CT) technology and radiation doses based on a set of questionnaires. Subjects were divided into two groups (Medical profession (Med, n=32) and Allied health profession (AH, n=88). The questionnaires are addressed: (1) demographic data (2) relative radiation dose and (3) knowledge of current CT technology. One-third of respondents from both groups were able to estimate relative radiation dose for routine CT examinations. 68% of the allied health profession personnel knew of the Malaysia regulations entitled ‘Basic Safety Standard (BSS) 2010’, although notably 80% of them had previously attended a radiation protection course. No significant difference (p < 0.05) in mean scores of CT technology knowledge detected between the two groups, with the medical professions producing a mean score of (26.7 ± 2.7) and the allied health professions a mean score of (25.2 ± 4.3). This study points to considerable variation among the respondents concerning their understanding of knowledge and awareness of risks of radiation and CT optimization techniques.

  5. Assessment of Annual Effective Dose for Natural Radioactivity of Gamma Emitters in Biscuit Samples in Iraq.

    Science.gov (United States)

    Abojassim, Ali Abid; Al-Alasadi, Lubna A; Shitake, Ahmed R; Al-Tememie, Faeq A; Husain, Afnan A

    2015-09-01

    Biscuits are an important type of food, widely consumed by babies in Iraq and other countries. This work uses gamma spectroscopy to measure the natural radioactivity due to long-lived gamma emitters in children's biscuits; it also estimates radiation hazard indices, that is, the radium equivalent activity, the representative of gamma level index, the internal hazard index, and the annual effective dose in children. Ten samples were collected from the Iraqi market from different countries of origin. The average specific activities for (226)Ra, (232)Th, and (40)K were 9.390, 3.1213, and 214.969 Bq/kg, respectively, but the average of the radium equivalent activity and the internal hazard index were 33.101 Bq/kg and 0.107, respectively. The total average annual effective dose from consumption by adults, children, and infants is estimated to be 0.655, 1.009, and 0.875 mSv, respectively. The values found for specific activity, radiation hazard indices, and annual effective dose in all samples in this study were lower than worldwide median values for all groups; therefore, these values are found to be safe.

  6. Postremediation dose assessment for the Elza Gate site, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Nimmagadda, M.; Yu, C.

    1993-03-01

    Potential maximum radiation dose rates were calculated for the Elza Gate site in Oak Ridge, Tennessee. The RESRAD computer code, which implements the methodology described in the US Department of Energy's manual for implementing residual radioactive material guidelines, was used in this evaluation. Currently, the site is not being used. Four potential future use scenarios were considered for the Elza Gate site; the scenarios vary with regard to time spent at the site, sources of water used, and sources of food consumed. In Scenario A (the expected scenario), industrial use of the site is assumed; in Scenario B (a plausible scenario), recreational use of the site is assumed. Both Scenarios C and D (possible but unlikely scenarios) assume the presence of a resident farmer in the immediate vicinity of the site. The difference between Scenarios C and D is the source of water used. For Scenario C, an adjacent pond provides 100% of the water for drinking, irrigation, and raising livestock; for Scenario D, groundwater drawn from a well located at the downgradient edge of the contaminated zone is the only source of water for drinking, investigation, and raising livestock. The results of the evaluation indicate that the US Department of Energy dose limit of 100 mrem/yr would not be exceeded for any scenario. The potential maximum dose rates for Scenarios A, B, C, and D are 1.5, 0.66, 12, and 42 mrem/yr, respectively.

  7. Postremediation dose assessment for the Elza Gate site, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Nimmagadda, M.; Yu, C.

    1993-03-01

    Potential maximum radiation dose rates were calculated for the Elza Gate site in Oak Ridge, Tennessee. The RESRAD computer code, which implements the methodology described in the US Department of Energy`s manual for implementing residual radioactive material guidelines, was used in this evaluation. Currently, the site is not being used. Four potential future use scenarios were considered for the Elza Gate site; the scenarios vary with regard to time spent at the site, sources of water used, and sources of food consumed. In Scenario A (the expected scenario), industrial use of the site is assumed; in Scenario B (a plausible scenario), recreational use of the site is assumed. Both Scenarios C and D (possible but unlikely scenarios) assume the presence of a resident farmer in the immediate vicinity of the site. The difference between Scenarios C and D is the source of water used. For Scenario C, an adjacent pond provides 100% of the water for drinking, irrigation, and raising livestock; for Scenario D, groundwater drawn from a well located at the downgradient edge of the contaminated zone is the only source of water for drinking, investigation, and raising livestock. The results of the evaluation indicate that the US Department of Energy dose limit of 100 mrem/yr would not be exceeded for any scenario. The potential maximum dose rates for Scenarios A, B, C, and D are 1.5, 0.66, 12, and 42 mrem/yr, respectively.

  8. Natural radioactivity, dose assessment and uranium uptake by agricultural crops at Khan Al-Zabeeb, Jordan

    Energy Technology Data Exchange (ETDEWEB)

    Al-Kharouf, Samer J. [Royal Scientific Society, Amman 11941 (Jordan); Al-Hamarneh, Ibrahim F. [Prince Abdullah Bin Ghazi Faculty of Science and IT, Al-Balqa Applied University (BAU), Salt 19117 (Jordan)], E-mail: hamarnehibrahim@yahoo.com; Dababneh, Munir [Prince Abdullah Bin Ghazi Faculty of Science and IT, Al-Balqa Applied University (BAU), Salt 19117 (Jordan)

    2008-07-15

    Khan Al-Zabeeb, an irrigated cultivated area lies above a superficial uranium deposits, is regularly used to produce vegetables and fruits consumed by the public. Both soil and plant samples collected from the study area were investigated for their natural radioactivity to determine the uranium uptake by crops and hence to estimate the effective dose equivalent to human consumption. Concentrations of {sup 238}U, {sup 235}U, {sup 232}Th, {sup 226}Ra, {sup 222}Rn, {sup 137}Cs and {sup 40}K in nine soil profiles were measured by gamma-ray spectrometry whereas watermelon and zucchini crops were analyzed for their uranium content by means of alpha spectrometry after radiochemical separation. Correlations between measured radionuclides were made and their activity ratios were determined to evaluate their geochemical behavior in the soil profiles. Calculated soil-plant transfer factors indicate that the green parts (leaves, stems and roots) of the studied crops tend to accumulate uranium about two orders of magnitude higher than the fruits. The maximum dose from ingestion of 1 kg of watermelon pulp was estimated to be 3.1 and 4.7 nSv y{sup -1} for {sup 238}U and {sup 234}U, respectively. Estimations of the annual effective dose equivalent due to external exposure showed extremely low values. Radium equivalent activity and external hazard index were seen to exceed the permissible limits of 370 Bq kg{sup -1} and 1, respectively.

  9. {sup 137}Cs and {sup 210}Po dose assessment from marine food in Cienfuegos Bay (Cuba)

    Energy Technology Data Exchange (ETDEWEB)

    Alonso-Hernandez, C. E-mail: carlos@ceac.perla.inf.cu; Diaz-Asencio, M.; Munos-Caravaca, A.; Suarez-Morell, E.; Avila-Moreno, R

    2002-07-01

    One part of Radiological Monitoring Programme in central Cuba (1991-1995) was dedicated to study the background levels of natural and anthropogenic radioactivity in Cienfuegos Bay in the vicinity of the first Cuban nuclear power station under construction. {sup 210}Po and {sup 137}Cs concentrations in fish, molluscs and crustaceans collected in Cienfuegos Bay were determined and the committed effective doses (CED) were calculated for two population groups inhabiting this region. The highest values of {sup 210}Po concentrations were found in crustaceans, but significant accumulation was also observed in fish and molluscs. The mean {sup 137}Cs concentrations in organisms are several times lower with respect to {sup 210}Po, a situation that characterises the regions affected by the global fallout only. Values of CED from the consumption of crustaceans and molluscs are very low both from{sup 210}Po and {sup 137}Cs. The mean individual dose from {sup 210}Po in the seafood consumed varies from 39 {mu}Sv for general populations to 2802 {mu}Sv for the 'critical group' consuming 320 kg of fish per year. The dose from {sup 137}Cs is negligible.

  10. Information on Hydrologic Conceptual Models, Parameters, Uncertainty Analysis, and Data Sources for Dose Assessments at Decommissioning Sites

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Philip D.; Gee, Glendon W.; Nicholson, Thomas J.

    2000-02-28

    This report addresses issues related to the analysis of uncertainty in dose assessments conducted as part of decommissioning analyses. The analysis is limited to the hydrologic aspects of the exposure pathway involving infiltration of water at the ground surface, leaching of contaminants, and transport of contaminants through the groundwater to a point of exposure. The basic conceptual models and mathematical implementations of three dose assessment codes are outlined along with the site-specific conditions under which the codes may provide inaccurate, potentially nonconservative results. In addition, the hydrologic parameters of the codes are identified and compared. A methodology for parameter uncertainty assessment is outlined that considers the potential data limitations and modeling needs of decommissioning analyses. This methodology uses generic parameter distributions based on national or regional databases, sensitivity analysis, probabilistic modeling, and Bayesian updating to incorporate site-specific information. Data sources for best-estimate parameter values and parameter uncertainty information are also reviewed. A follow-on report will illustrate the uncertainty assessment methodology using decommissioning test cases.

  11. MODARIA WG5: Towards a practical guidance for including uncertainties in the results of dose assessment of routine releases

    Energy Technology Data Exchange (ETDEWEB)

    Mora, Juan C. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas - CIEMAT (Spain); Telleria, Diego [International Atomic Energy Agency - IAEA (Austria); Al Neaimi, Ahmed [Emirates Nuclear Energy Corporation - ENEC (United Arab Emirates); Blixt Buhr, Anna Ma [Vattenfall AB (Sweden); Bonchuk, Iurii [Radiation Protection Institute - RPI (Ukraine); Chouhan, Sohan [Atomic Energy of Canada Limited - AECL (Canada); Chyly, Pavol [SE-VYZ (Slovakia); Curti, Adriana R. [Autoridad Regulatoria Nuclear - ARN (Argentina); Da Costa, Dejanira [Instituto de Radioprotecao e Dosimetria - IRD (Brazil); Duran, Juraj [VUJE Inc (Slovakia); Galeriu, Dan [Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN-HH (Romania); Haegg, Ann- Christin; Lager, Charlotte [Swedish Radiation Safety Authority - SSM (Sweden); Heling, Rudie [Nuclear Research and Consultancy Group - NRG (Netherlands); Ivanis, Goran; Shen, Jige [Ecometrix Incorporated (Canada); Iosjpe, Mikhail [Norwegian Radiation Protection Authority - NRPA (Norway); Krajewski, Pawel M. [Central Laboratory for Radiological Protection - CLOR (Poland); Marang, Laura; Vermorel, Fabien [Electricite de France - EdF (France); Mourlon, Christophe [Institut de Radioprotection et de Surete Nucleaire - IRSN (France); Perez, Fabricio F. [Belgian Nuclear Research Centre - SCK (Belgium); Woodruffe, Andrew [Federal Authority for Nuclear Regulation - FANR (United Arab Emirates); Zorko, Benjamin [Jozef Stefan Institute (Slovenia)

    2014-07-01

    MODARIA (Modelling and Data for Radiological Impact Assessments) project was launched in 2012 with the aim of improving the capabilities in radiation dose assessment by means of acquisition of improved data for model testing, model testing and comparison, reaching consensus on modelling philosophies, approaches and parameter values, development of improved methods and exchange of information. The project focuses on areas where uncertainties remain in the predictive capability of environmental models, emphasizing in reducing associated uncertainties or developing new approaches to strengthen the evaluation of the radiological impact. Within MODARIA, four main areas were defined, one of them devoted to Uncertainty and Variability. In this area four working groups were included, Working Group 5 dealing with the 'uncertainty and variability analysis for assessments of radiological impacts arising from routine discharges of radionuclides'. Whether doses are estimated by using measurement data, by applying models, or through a combination of measurements and calculations, the variability and uncertainty contribute to a distribution of possible values. The degree of variability and uncertainty is represented by the shape and extent of that distribution. The main objective of WG5 is to explore how to consider uncertainties and variabilities in the results of assessment of doses in planned situations for controlling the impact of routine releases from radioactive and nuclear installations to the environment. The final aim is to produce guidance for the calculation of uncertainties in these exposure situations and for the presentation of such results to the different stakeholders. To achieve that objective the main tasks identified were: to find tools and methods for uncertainty and variability analysis applicable to dose assessments in routine radioactive discharges, to define scenarios where information on uncertainty and variability of parameters is available

  12. Dosimetric characterization and organ dose assessment in digital breast tomosynthesis: Measurements and Monte Carlo simulations using voxel phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Baptista, Mariana, E-mail: marianabaptista@ctn.ist.utl.pt; Di Maria, Salvatore; Barros, Sílvia; Vaz, Pedro [Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, km 139,7, Bobadela LRS 2695-066 (Portugal); Figueira, Catarina [Centre for Plasma Physics, School of Mathematics and Physics, Queen’s University, Belfast BT7 1NN (United Kingdom); Sarmento, Marta; Orvalho, Lurdes [Serviço de Imagiologia, Hospital da Luz, Avenida Lusíada, 100, Lisboa 1500-650 (Portugal)

    2015-07-15

    Purpose: Due to its capability to more accurately detect deep lesions inside the breast by removing the effect of overlying anatomy, digital breast tomosynthesis (DBT) has the potential to replace the standard mammography technique in clinical screening exams. However, the European Guidelines for DBT dosimetry are still a work in progress and there are little data available on organ doses other than to the breast. It is, therefore, of great importance to assess the dosimetric performance of DBT with respect to the one obtained with standard digital mammography (DM) systems. The aim of this work is twofold: (i) to study the dosimetric properties of a combined DBT/DM system (MAMMOMAT Inspiration Siemens{sup ®}) for a tungsten/rhodium (W/Rh) anode/filter combination and (ii) to evaluate organs doses during a DBT examination. Methods: For the first task, measurements were performed in manual and automatic exposure control (AEC) modes, using two homogeneous breast phantoms: a PMMA slab phantom and a 4 cm thick breast-shaped rigid phantom, with 50% of glandular tissue in its composition. Monte Carlo (MC) simulations were performed using Monte Carlo N-Particle eXtended v.2.7.0. A MC model was implemented to mimic DM and DBT acquisitions for a wide range of x-ray spectra (24 –34 kV). This was used to calculate mean glandular dose (MGD) and to compute series of backscatter factors (BSFs) that could be inserted into the DBT dosimetric formalism proposed by Dance et al. Regarding the second aim of the study, the implemented MC model of the clinical equipment, together with a female voxel phantom (“Laura”), was used to calculate organ doses considering a typical DBT acquisition. Results were compared with a standard two-view mammography craniocaudal (CC) acquisition. Results: Considering the AEC mode, the acquisition of a single CC view results in a MGD ranging from 0.53 ± 0.07 mGy to 2.41 ± 0.31 mGy in DM mode and from 0.77 ± 0.11 mGy to 2.28 ± 0.32 mGy in DBT mode

  13. Evaluation of the Comet Assay for Assessing the Dose-Response Relationship of DNA Damage Induced by Ionizing Radiation

    Directory of Open Access Journals (Sweden)

    Qiang Liu

    2013-11-01

    Full Text Available Dose- and time-response curves were combined to assess the potential of the comet assay in radiation biodosimetry. The neutral comet assay was used to detect DNA double-strand breaks in lymphocytes caused by γ-ray irradiation. A clear dose-response relationship with DNA double-strand breaks using the comet assay was found at different times after irradiation (p < 0.001. A time-response relationship was also found within 72 h after irradiation (p < 0.001. The curves for DNA double-strand breaks and DNA repair in vitro of human lymphocytes presented a nice model, and a smooth, three-dimensional plane model was obtained when the two curves were combined.

  14. Objective Assessment of Sunburn and Minimal Erythema Doses: Comparison of Noninvasive In Vivo Measuring Techniques after UVB Irradiation

    Directory of Open Access Journals (Sweden)

    Lo Pei-Yu

    2010-01-01

    Full Text Available Military personnel movement is exposed to solar radiation and sunburn is a major problem which can cause lost workdays and lead to disciplinary action. This study was designed to identify correlation parameters in evaluating in vivo doses and epidermis changes following sunburn inflammation. Several noninvasive bioengineering techniques have made objective evaluations possible. The volar forearms of healthy volunteers ( , 2 areas, 20 mm in diameter, were irradiated with UVB 100 mj/ and 200 mj/ , respectively. The skin changes were recorded by several monitored techniques before and 24 hours after UV exposures. Our results showed that chromameter value provides more reliable information and can be adopted with mathematical model in predicting the minimal erythema dose (MED which showed lower than visual assessment by 10 mj/ (Pearson correlation coefficient . A more objective measure for evaluation of MED was established for photosensitive subjects' prediction and sunburn risks prevention.

  15. Development and operation of the network system for nuclear safety - Improvement of the following accident dose assessment system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Enn Han; Han, Moon Hee; Suh, Kyung Suk; Hwang, Won Tae [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-12-01

    The FADAS has been updates for calculating the real-time wind fields continuously at the nuclear sites in Korea. The system has been constructed to compute the wind fields using its own process for the dummy meteorological data, and does not effect on the overall wind field module. If the radioactive materials are released into the atmosphere in real situation, the calculations of wind fields and exposure dose in the previous FADAS are performed in the case of the recognition of the above situation in the source term evaluation module. The current version of FADAS includes the program for evaluating the effect of the predicted accident and the assumed scenario together. The dose assessment module is separated into the real-time and the supposed accident respectively. 8 refs., 17 figs., 10 tabs. (Author)

  16. Assessment of shoulder position variation and its impact on IMRT and VMAT doses for head and neck cancer

    Directory of Open Access Journals (Sweden)

    Neubauer Emily

    2012-02-01

    Full Text Available Abstract Background For radiotherapy of the head and neck, 5-point mask immobilization is used to stabilize the shoulders. Still, the daily position of the shoulders during treatment may be different from the position in the treatment plan despite correct isocenter setup. The purpose of this study was to determine the interfractional displacement of the shoulders relative to isocenter over the course of treatment and the associated dosimetric effect of this displacement. Methods The extent of shoulder displacements relative to isocenter was assessed for 10 patients in 5-point thermoplastic masks using image registration and daily CT-on-rails scans. Dosimetric effects on IMRT and VMAT plans were evaluated in Pinnacle based on simulation CTs modified to represent shoulder shifts between 3 and 15 mm in the superior-inferior, anterior-posterior, and right-left directions. The impact of clinically observed shoulder shifts on the low-neck dose distributions was examined. Results Shoulder motion was 2-5 mm in each direction on average but reached 20 mm. Superior shifts resulted in coverage loss, whereas inferior shifts increased the dose to the brachial plexus. These findings were generally consistent for both IMRT and VMAT plans. Over a course of observed shifts, the dose to 99% of the CTV decreased by up to 101 cGy, and the brachial plexus dose increased by up to 72 cGy. Conclusions he position of the shoulder affects target coverage and critical structure dose, and may therefore be a concern during the setup of head and neck patients, particularly those with low neck primary disease.

  17. Naturally occurring radioactivity in some Swedish concretes and their constituents - Assessment by using I-index and dose-model.

    Science.gov (United States)

    Döse, M; Silfwerbrand, J; Jelinek, C; Trägårdh, J; Isaksson, M

    2016-05-01

    The reference level for effective dose due to gamma radiation from building materials and construction products used for dwellings is set to 1 mSv per year (EC, 1996, 1999), (CE, 2014). Given the specific conditions presented by the EC in report 112 (1999) considering building and construction materials, an I-index of 1 may generate an effective dose of 1 mSv per year. This paper presents a comparison of the activity concentrations of (4)(0)K, (226)Ra and (232)Th of aggregates and when these aggregates constitute a part of concrete. The activity concentration assessment tool for building and construction materials, the I-index, introduced by the EC in 1996, is used in the comparison. A comparison of the I-indices values are also made with a recently presented dose model by Hoffman (2014), where density variations of the construction material and thickness of the construction walls within the building are considered. There was a ∼16-19% lower activity index in concretes than in the corresponding aggregates. The model by Hoffman further implies that the differences between the I-indices of aggregates and the concretes' final effective doses are even larger. The difference is due, mainly to a dilution effect of the added cement with low levels of natural radioisotopes, but also to a different and slightly higher subtracted background value (terrestrial value) used in the modeled calculation of the revised I-index by Hoffman (2014). Only very minimal contributions to the annual dose could be related to the water and additives used, due to their very low content of radionuclides reported.

  18. Assessment of shoulder position variation and its impact on IMRT and VMAT doses for head and neck cancer

    Science.gov (United States)

    2012-01-01

    Background For radiotherapy of the head and neck, 5-point mask immobilization is used to stabilize the shoulders. Still, the daily position of the shoulders during treatment may be different from the position in the treatment plan despite correct isocenter setup. The purpose of this study was to determine the interfractional displacement of the shoulders relative to isocenter over the course of treatment and the associated dosimetric effect of this displacement. Methods The extent of shoulder displacements relative to isocenter was assessed for 10 patients in 5-point thermoplastic masks using image registration and daily CT-on-rails scans. Dosimetric effects on IMRT and VMAT plans were evaluated in Pinnacle based on simulation CTs modified to represent shoulder shifts between 3 and 15 mm in the superior-inferior, anterior-posterior, and right-left directions. The impact of clinically observed shoulder shifts on the low-neck dose distributions was examined. Results Shoulder motion was 2-5 mm in each direction on average but reached 20 mm. Superior shifts resulted in coverage loss, whereas inferior shifts increased the dose to the brachial plexus. These findings were generally consistent for both IMRT and VMAT plans. Over a course of observed shifts, the dose to 99% of the CTV decreased by up to 101 cGy, and the brachial plexus dose increased by up to 72 cGy. Conclusions he position of the shoulder affects target coverage and critical structure dose, and may therefore be a concern during the setup of head and neck patients, particularly those with low neck primary disease. PMID:22316381

  19. Dose Assessment of Cefquinome by Pharmacokinetic/Pharmacodynamic Modeling in Mouse Model of Staphylococcus aureus Mastitis

    Science.gov (United States)

    Yu, Yang; Zhou, Yu-Feng; Li, Xiao; Chen, Mei-Ren; Qiao, Gui-Lin; Sun, Jian; Liao, Xiao-Ping; Liu, Ya-Hong

    2016-01-01

    This work aimed to characterize the mammary gland pharmacokinetics of cefquinome after an intramammary administration and integrate pharmacokinetic/pharmacodynamic model. The pharmacokinetic profiles of cefquinome in gland tissue were measured using high performance liquid chromatograph. Therapeutic regimens covered various dosages ranging from 25 to 800 μg/gland and multiple dosing intervals of 8, 12, and 24 h. The in vivo bacterial killing activity elevated when dosage increased or when dosing intervals were shortened. The best antibacterial effect was demonstrated by a mean 1.5 log10CFU/gland visible count reduction. On the other hand, the results showed that the percentage of time duration of drug concentration exceeding the MIC during a dose interval (%T > MIC) was generally 100% because of the influence of drug distribution caused by the blood-milk barrier. Therefore, pharmacokinetic/pharmacodynamic parameter of the ratio of area under the concentration-time curve over 24 h to the MIC (AUC0-24/MIC) was used to describe the efficacy of cefquinome instead of %T > MIC. When the magnitude of AUC0-24/MIC exceeding 16571.55 h⋅mL/g, considerable activity of about 1.5 log10CFU/g gland bacterial count reduction was observed in vivo. Based on the Monte Carlo simulation, the clinical recommended regimen of three infusions of 75 mg per quarter every 12 h can achieve a 76.67% cure rate in clinical treatment of bovine mastitis caused by Staphylococcus aureus infection. PMID:27774090

  20. Assessment of dose due to exposure to indoor radon and thoron progeny

    Directory of Open Access Journals (Sweden)

    Prasad Ganesh

    2010-01-01

    Full Text Available The components of the effective dose through inhalation from radon and its progeny are important for human health since they contribute to more than 50% of the total radiation dose from natural sources. As a consequence, radon has been identified as the second leading cause of lung cancer after smoking. Radon and its short lived decay products (218Po, 214Pb, 214Bi, 214Po present in dwellings are a radiation hazard, particularly if such sources are concentrated in the enclosed areas like poorly ventilated houses and underground mines. The indoor radon, thoron, and progeny concentrations were measured in a small hilly town of Budhakedar and the surrounding area of Tehri Garhwal, India, by using LR-115 Type II plastic track detector in a twin cup radon dosimeter. The concentrations of radon progeny were measured as the highest in winter and the lowest in summer while the thoron progeny concentration was found maximum in rainy season and minimum in autumn. The annual exposure to the potential alpha energy of radon and thoron were found to vary from 0.04 WLM to 0.69 WLM with an average value of 0.29 WLM, and 0.03 WLM to 0.37 WLM with an aver- age value of 0.16 WLM, respectively. The annual effective dose due to the exposure to indoor radon and progeny in Budhakedar homes was found to vary from 0.16 mSv to 2.72 mSv with an average value of 1.14 mSv and the effective dose due to the exposure to thoron and progeny was found to vary from 0.18 mSv to 2.49 mSv with an average value of 1.05 mSv. The results of systematic study have been obtained by considering the room as a space in which the radon and thoron levels are directly related to the dynamic and static parameters.

  1. Measurement of naturally occurring radionuclides in geothermal samples and assessment of radiological risks and radiation doses.

    Science.gov (United States)

    Parmaksiz, A

    2013-12-01

    The analysis of (226)Ra, (232)Th and (40)K radionuclides has been carried out in geothermal water and residue samples collected from six wells of geothermal power plant and disposal site, using gamma-spectrometry system equipped with a high-purity germanium detector. The activity concentrations of nine geothermal water samples were found to be lower than minimum detectable activity (MDA) values. The activity concentration of the residue samples ranged from 40 ± 4 to 2694 ± 85 Bq kg(-1) for (226)Ra, 33 ± 4 to 2388 ± 85 Bq kg(-1) for (232)Th, and MDA value to 967 ± 30 Bq kg(-1) for (40)K. In the study, some radiological indexes were examined and found to be higher than the reference values for majority of the residue samples. The annual effective doses arising from some residue samples were calculated to be higher than the permitted dose rate for the public, i.e. 1 mSv y(-1).

  2. Indoor radon concentrations and assessment of doses in four districts of the Punjab Province - Pakistan.

    Science.gov (United States)

    Ur-Rahman, Saeed; Rafique, Muhammad; Matiullah; Anwar, Javaid

    2009-11-01

    Seasonal indoor radon measurement studies have been carried out in four districts, namely, Jhelum, Chakwal, Rawalpindi and Attock of the Punjab Province. In this regard, CR-39 based detectors were installed in bedrooms, drawing rooms and kitchens of 40 randomly selected houses in each district. After exposing to radon in each season, CR-39 detectors were etched in 6M NaOH at 80 degrees C and counted under an optical microscope. Indoor radon activity concentrations in the houses surveyed ranged from 15 +/- 4 to 176 +/- 7 Bq m(-3) with an overall average value of 55 +/- 31 Bq m(-3). The observed annual average values are greater than the world average of 40 Bq m(-3). Maximum indoor radon concentration levels were observed in winter season whereas minimum levels were observed in summer season. None of the measured radon concentration value exceeded the action level of 200-400 Bq m(-3). The season/annual ratios for different type of dwellings varied from 0.87 +/- 0.93 to 1.14 +/- 1.10. The mean annual estimated effective dose received by the residents of the studied area was found to be 1.39 +/- 0.78 mSv. The annual estimated effective dose is less than the recommended action level (3-10 mSv).

  3. Evaluation of a low-dose CT protocol with oral contrast for assessment of acute appendicitis

    Energy Technology Data Exchange (ETDEWEB)

    Platon, Alexandra; Jlassi, Helmi; Becker, Christoph D.; Poletti, Pierre-Alexandre [University Hospital of Geneva, Department of Radiology, Geneva 14 (Switzerland); Rutschmann, Olivier T. [University Hospital of Geneva, Emergency Center, Geneva (Switzerland); Verdun, Francis R. [University Institute for Radiation Physics, Lausanne (Switzerland); Gervaz, Pascal [University Hospital of Geneva, Clinic of Digestive Surgery, Geneva (Switzerland)

    2009-02-15

    The aim of this study was to evaluate a low-dose CT with oral contrast medium (LDCT) for the diagnosis of acute appendicitis and compare its performance with standard-dose i.v. contrast-enhanced CT (standard CT) according to patients' BMIs. Eighty-six consecutive patients admitted with suspicion of acute appendicitis underwent LDCT (30 mAs), followed by standard CT (180 mAs). Both examinations were reviewed by two experienced radiologists for direct and indirect signs of appendicitis. Clinical and surgical follow-up was considered as the reference standard. Appendicitis was confirmed by surgery in 37 (43%) of the 86 patients. Twenty-nine (34%) patients eventually had an alternative discharge diagnosis to explain their abdominal pain. Clinical and biological follow-up was uneventful in 20 (23%) patients. LDCT and standard CT had the same sensitivity (100%, 33/33) and specificity (98%, 45/46) to diagnose appendic