Radiation-absorbed doses and energy imparted from panoramic tomography, cephalometric radiography, and occlusal film radiography in children

International Nuclear Information System (INIS)

Bankvall, G.; Hakansson, H.A.

1982-01-01

The absorbed doses and energy imparted from radiographic examinations of children, using panoramic tomography (PTG), cephalometric radiography (CPR), and maxillary frontal occlusal overview (FOO), were examined. The absorbed dose at various sites of the head were measured with TL dosimeters in a phantom and in patients. The energy imparted was calculated from measurements of areal exposure using a planparallel ionization chamber. The maximum absorbed doses for panoramic tomography were located around the lateral rotation center, for cephalometric radiography in the left (tube side) parotid region, and for frontal occlusal radiography in the nose. The absorbed doses in the eyes, thyroid gland, and skin are discussed and compared with previous reports and, for the most part, are found to be in agreement. The mean energy imparted from all three examination methods is 5 mJ with about 57 percent from panoramic, 33 percent from cephalometric, and 10 percent from frontal occlusal examinations. The energy imparted from cephalometric radiography can be reduced to about 10 percent with the use of an improved examination technique, leaving panoramic tomography responsible for contributing about 80 percent of the total energy imparted

Radiation dose in hysterosalpingography: modern 100mm fluorography vs. full-scale radiography

International Nuclear Information System (INIS)

Seppaenen, S.; Lehtinen, E.; Holli, H.

1978-01-01

Radiation doses of modern 100 mm fluorography and full-scale radiography were compared experimentally and applied to hysterosalpingography. It was determined that 100 mm fluorography reduced the doses by 28 to 29 percent per exposure and 37 to 47 percent per examination compared with full-scale radiography performed with fast tungstate screens in identical conditions (70 to 80 kV, 400 mA). The dose during one minute of videofluoroscopy was equivalent to the doses produced by one exposure in full-scale filming and three to four exposures in 100 mm filming. Although electronic magnification in 100 mm fluorography increases the doses by two or threefold, these are still less than the doses in full-scale radiography

Studies on image quality and dose exposure in chest radiography in children

International Nuclear Information System (INIS)

Schumacher, R.

1985-01-01

Chest radiography accounts for almost 50% of all radiographies in radiological departments for children, thus clearly dominating X-ray performances. The indications for examination in children are frequent infections of the upper airways, congenital cardiac defects, and controls in oncological patients. By contrast, indications for radioscopy of the chest organs which figure greatly in adult age and are often required concurrently with every chest radiography, are rather rare in the patient group of a paediatric X-ray department with their rate of c. 0.5% related to chest radiography. Chest radiographs and phantom radiographs were produced using different techniques and were compared by means of subjective and objective image quality parameters. Concurrently, thermoluminescence dosimetry was used to perform dose measurements of the small gonadal dose occurring in patients in chest radiographies. The study aimed at finding a chest radiography technique appropriate for use in paediatric radiology while considering both image quality parameters and the radiation dose required for producing pictures. (orig./DG) [de

Dose-area product measurement for patients in diagnostic radiography

International Nuclear Information System (INIS)

Alkhawad, Safaa Ibrahim Awad Elkarim

2001-09-01

There is a wide spread of the utilization of medical diagnostic x-ray in Sudan upon the last years, in private clinics as well as in public hospitals. The aim of this study was to measure the doses to patients from x-ray in radiography departments in Khartoum State. Use was made of ionization chamber that measures the product of dose times the exposed area of the patient in units of Gy cm 2 . The work was performed in 7 hospitals over 250 patients. 71.2% of the patients were males and 28.8% females. From this work, it appears that the chest radiography represent 42% of the total exposure of human body organs to radiography, there was also a clear variation in doses resulting from this exposure for different x-ray machines. The results of this study were compared with similar from Germany, Finland, New Zealand and Norway; which are recently available studies. The comparison showed those investigation of abdomen, spine and pelvis result in higher radiation doses. No data for limb exposure were obtained from these countries, in Sudan exposure of the limb carry radiation doses compared to the rest of the human body.(Author)

Evaluation of radiation dose to patients in intraoral dental radiography using Monte Carlo Method

International Nuclear Information System (INIS)

Park, Il; Kim, Kyeong Ho; Oh, Seung Chul; Song, Ji Young

2016-01-01

The use of dental radiographic examinations is common although radiation dose resulting from the dental radiography is relatively small. Therefore, it is required to evaluate radiation dose from the dental radiography for radiation safety purpose. The objectives of the present study were to develop dosimetry method for intraoral dental radiography using a Monte Carlo method based radiation transport code and to calculate organ doses and effective doses of patients from different types of intraoral radiographies. Radiological properties of dental radiography equipment were characterized for the evaluation of patient radiation dose. The properties including x-ray energy spectrum were simulated using MCNP code. Organ doses and effective doses to patients were calculated by MCNP simulation with computational adult phantoms. At the typical equipment settings (60 kVp, 7 mA, and 0.12 sec), the entrance air kerma was 1.79 mGy and the measured half value layer was 1.82 mm. The half value layer calculated by MCNP simulation was well agreed with the measurement values. Effective doses from intraoral radiographies ranged from 1 μSv for maxilla premolar to 3 μSv for maxilla incisor. Oral cavity layer (23⁓82 μSv) and salivary glands (10⁓68 μSv) received relatively high radiation dose. Thyroid also received high radiation dose (3⁓47 μSv) for examinations. The developed dosimetry method and evaluated radiation doses in this study can be utilized for policy making, patient dose management, and development of low-dose equipment. In addition, this study can ultimately contribute to decrease radiation dose to patients for radiation safety

Evaluation of radiation dose to patients in intraoral dental radiography using Monte Carlo Method

Energy Technology Data Exchange (ETDEWEB)

Park, Il; Kim, Kyeong Ho; Oh, Seung Chul; Song, Ji Young [Dept. of Nuclear Engineering, Kyung Hee University, Yongin (Korea, Republic of)

2016-11-15

The use of dental radiographic examinations is common although radiation dose resulting from the dental radiography is relatively small. Therefore, it is required to evaluate radiation dose from the dental radiography for radiation safety purpose. The objectives of the present study were to develop dosimetry method for intraoral dental radiography using a Monte Carlo method based radiation transport code and to calculate organ doses and effective doses of patients from different types of intraoral radiographies. Radiological properties of dental radiography equipment were characterized for the evaluation of patient radiation dose. The properties including x-ray energy spectrum were simulated using MCNP code. Organ doses and effective doses to patients were calculated by MCNP simulation with computational adult phantoms. At the typical equipment settings (60 kVp, 7 mA, and 0.12 sec), the entrance air kerma was 1.79 mGy and the measured half value layer was 1.82 mm. The half value layer calculated by MCNP simulation was well agreed with the measurement values. Effective doses from intraoral radiographies ranged from 1 μSv for maxilla premolar to 3 μSv for maxilla incisor. Oral cavity layer (23⁓82 μSv) and salivary glands (10⁓68 μSv) received relatively high radiation dose. Thyroid also received high radiation dose (3⁓47 μSv) for examinations. The developed dosimetry method and evaluated radiation doses in this study can be utilized for policy making, patient dose management, and development of low-dose equipment. In addition, this study can ultimately contribute to decrease radiation dose to patients for radiation safety.

Low-dose ion-based transmission radiography and tomography for optimization of carbon ion-beam therapy

Energy Technology Data Exchange (ETDEWEB)

Magallanes Hernandez, Lorena

2017-02-21

In the last few decades, ion-beam radiotherapy has emerged as a highly effective tumor treatment modality. Its success relies on the capability to precisely confine the prescribed dose within the target volume, due to the inverted depth-dose profile and the finite range featured by charged particles. However, to fully exploit the physical and biological advantages of ion-beams, it is necessary to prioritize on innovative imaging techniques to monitor the ion-range inside the patient. Main range uncertainties result from X-ray-based calibration of the ion relative Water Equivalent Path Length (rWEPL) during the planning phase, and patient anatomical or positioning variation during the treatment. In this thesis, low-dose carbon-ion transmissionimaging performed with a Residual Range Detector (RRD) is proposed as imaging strategy for actively scanned beam delivery facilities. It enables the verification of the beam range and the patient positioning with ion-radiographies (iRAD), and ion computed tomographies (iCT) can directly provide the ion stopping-power of the traversed tissue for treatment planning purposes. First experimental investigations aiming to minimize the imaging dose to the object are presented. The performance of the integration-mode multi-channel array of 61 parallel-plate ionization chambers (PPICs), interleaved with 3 mm thickness PMMA slabs, was thoroughly investigated for low-fluence irradiation. This characterization has been pursued in terms of beam-monitoring performance at the Heidelberg Ion-beam Therapy Center (HIT, Heidelberg, Germany), RRD signal-to-noise ratio (SNR), RRD charge-collection efficiency and drift voltage applied to the PPICs. Pixel-wise metrics for signal quality evaluation based on specific channel-charge features have been developed to support the visual assessment of the acquired images. Phantoms of different complexity and tissue-equivalent composition were imaged with high (5000 primaries per raster-scanning point (RP

Low-dose ion-based transmission radiography and tomography for optimization of carbon ion-beam therapy

International Nuclear Information System (INIS)

Magallanes Hernandez, Lorena

2017-01-01

In the last few decades, ion-beam radiotherapy has emerged as a highly effective tumor treatment modality. Its success relies on the capability to precisely confine the prescribed dose within the target volume, due to the inverted depth-dose profile and the finite range featured by charged particles. However, to fully exploit the physical and biological advantages of ion-beams, it is necessary to prioritize on innovative imaging techniques to monitor the ion-range inside the patient. Main range uncertainties result from X-ray-based calibration of the ion relative Water Equivalent Path Length (rWEPL) during the planning phase, and patient anatomical or positioning variation during the treatment. In this thesis, low-dose carbon-ion transmissionimaging performed with a Residual Range Detector (RRD) is proposed as imaging strategy for actively scanned beam delivery facilities. It enables the verification of the beam range and the patient positioning with ion-radiographies (iRAD), and ion computed tomographies (iCT) can directly provide the ion stopping-power of the traversed tissue for treatment planning purposes. First experimental investigations aiming to minimize the imaging dose to the object are presented. The performance of the integration-mode multi-channel array of 61 parallel-plate ionization chambers (PPICs), interleaved with 3 mm thickness PMMA slabs, was thoroughly investigated for low-fluence irradiation. This characterization has been pursued in terms of beam-monitoring performance at the Heidelberg Ion-beam Therapy Center (HIT, Heidelberg, Germany), RRD signal-to-noise ratio (SNR), RRD charge-collection efficiency and drift voltage applied to the PPICs. Pixel-wise metrics for signal quality evaluation based on specific channel-charge features have been developed to support the visual assessment of the acquired images. Phantoms of different complexity and tissue-equivalent composition were imaged with high (5000 primaries per raster-scanning point (RP

Dose audit for patients undergoing two common radiography examinations with digital radiology systems.

Science.gov (United States)

İnal, Tolga; Ataç, Gökçe

2014-01-01

We aimed to determine the radiation doses delivered to patients undergoing general examinations using computed or digital radiography systems in Turkey. Radiographs of 20 patients undergoing posteroanterior chest X-ray and of 20 patients undergoing anteroposterior kidney-ureter-bladder radiography were evaluated in five X-ray rooms at four local hospitals in the Ankara region. Currently, almost all radiology departments in Turkey have switched from conventional radiography systems to computed radiography or digital radiography systems. Patient dose was measured for both systems. The results were compared with published diagnostic reference levels (DRLs) from the European Union and International Atomic Energy Agency. The average entrance surface doses (ESDs) for chest examinations exceeded established international DRLs at two of the X-ray rooms in a hospital with computed radiography. All of the other ESD measurements were approximately equal to or below the DRLs for both examinations in all of the remaining hospitals. Improper adjustment of the exposure parameters, uncalibrated automatic exposure control systems, and failure of the technologists to choose exposure parameters properly were problems we noticed during the study. This study is an initial attempt at establishing local DRL values for digital radiography systems, and will provide a benchmark so that the authorities can establish reference dose levels for diagnostic radiology in Turkey.

Dose in conventional radiography; Dosis en radiografia convencional

Energy Technology Data Exchange (ETDEWEB)

Acuna D, E.; Padilla R, Z. P.; Escareno J, E.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98000 Zacatecas (Mexico)

2011-10-15

It has been pointed out that medical exposures are the most significant sources of exposure to ionizing radiation for the general population. Inside the medical exposures the most important is the X-ray use for diagnosis, which is by far the largest contribution to the average dose received by the population. From all studies performed in radiology the chest radiography is the most abundant. In an X-ray machine, voltage and current are combined to obtain a good image and a reduce dose, however due to the workload in a radiology service individual dose is not monitored. In order to evaluate the dose due to chest radiography in this work a plate phantom was built according to the ISO recommendations using methylmethacrylate walls and water. The phantom was used in the Imaging department of the Zacatecas General Hospital as a radiology patient asking for a chest study; using thermoluminescent dosimeters, TLD 100 the kerma at the surface entrance was determined. (Author)

Dose-image quality study in digital chest radiography using Monte Carlo simulation

International Nuclear Information System (INIS)

Correa, S.C.A.; Souza, E.M.; Silva, A.X.; Lopes, R.T.; Yoriyaz, H.

2008-01-01

One of the main preoccupations of diagnostic radiology is to guarantee a good image-sparing dose to the patient. In the present study, Monte Carlo simulations, with MCNPX code, coupled with an adult voxel female model (FAX) were performed to investigate how image quality and dose in digital chest radiography vary with tube voltage (80-150 kV) using air-gap technique and a computed radiography system. Calculated quantities were normalized to a fixed value of entrance skin exposure (ESE) of 0.0136 R. The results of the present analysis show that the image quality for chest radiography with imaging plate is improved and the dose reduced at lower tube voltage

Dose audit for patients undergoing two common radiography examinations with digital radiology systems

Science.gov (United States)

İnal, Tolga; Ataç, Gökçe

2014-01-01

PURPOSE We aimed to determine the radiation doses delivered to patients undergoing general examinations using computed or digital radiography systems in Turkey. MATERIALS AND METHODS Radiographs of 20 patients undergoing posteroanterior chest X-ray and of 20 patients undergoing anteroposterior kidney-ureter-bladder radiography were evaluated in five X-ray rooms at four local hospitals in the Ankara region. Currently, almost all radiology departments in Turkey have switched from conventional radiography systems to computed radiography or digital radiography systems. Patient dose was measured for both systems. The results were compared with published diagnostic reference levels (DRLs) from the European Union and International Atomic Energy Agency. RESULTS The average entrance surface doses (ESDs) for chest examinations exceeded established international DRLs at two of the X-ray rooms in a hospital with computed radiography. All of the other ESD measurements were approximately equal to or below the DRLs for both examinations in all of the remaining hospitals. Improper adjustment of the exposure parameters, uncalibrated automatic exposure control systems, and failure of the technologists to choose exposure parameters properly were problems we noticed during the study. CONCLUSION This study is an initial attempt at establishing local DRL values for digital radiography systems, and will provide a benchmark so that the authorities can establish reference dose levels for diagnostic radiology in Turkey. PMID:24317331

Radiation dose and cancer risk to children undergoing skull radiography

International Nuclear Information System (INIS)

Mazonakis, Michael; Damilakis, John; Raissaki, Maria; Gourtsoyiannis, Nicholas

2004-01-01

Background: Limited data exist in the literature concerning the patient-effective dose from paediatric skull radiography. No information has been provided regarding organ doses, patient dose during PA skull projection, risk of cancer induction and dose to comforters, i.e. individuals supporting children during exposure. Objective: To estimate patient-effective dose, organ doses, lifetime cancer mortality risk to children and radiation dose to comforters associated with skull radiography. Materials and methods: Data were collected from 136 paediatric examinations, including AP, PA and lateral skull radiographs. Entrance-surface dose (ESD) and dose to comforters were measured using thermoluminescent dosimeters. Patients were divided into the following age groups: 0.5-2, 3-7, 8-12 and 13-18 years. The patient-effective dose and corresponding organ doses were calculated using data from the NRPB and Monte Carlo techniques. The risk for fatal cancer induction was assessed using appropriate risk coefficients. Results: For AP, PA and lateral skull radiography, effective dose ranges were 8.8-25.4, 8.2-27.3 and 8.4-22.7 μSv respectively, depending upon the age of the child. For each skull projection, the organs receiving doses above 10 μGy are presented. The number of fatal cancers was found to be less than or equal to 2 per 1 million children undergoing a skull radiograph. The mean radiation dose absorbed by the hands of comforters was 13.4 μGy. Conclusions: The current study provides detailed tabular and graphical data on ESD, effective dose, organ doses and lifetime cancer mortality risk to children associated with AP, PA and lateral skull projections at all patient ages. (orig.)

Multiple-beam equalization radiography in chest radiology

International Nuclear Information System (INIS)

Axelsson, B.; Forsberg, H.; Hansson, B.; Haverling, M.

1991-01-01

The large difference in transmission between the mediastinum and the part of the chest mainly containing lungs causes major problems in chest radiography. A system for advanced multiple beam equalization radiography has been evaluated. Evaluation of image quality has been performed both using standard phantoms and from clinical radiographs. Measurements of radiation dose burden to the patient have been made both in clinical examinations and using an anthropomorphic phantom. The image quality, in areas with low transmission, is substantially increased using the equalization system. In parts of the chest mainly containing lung tissue, conventional systems show an equal or slightly better image quality. The radiation dose burden to the patient is increased by 25 percent using the equation system, as compared to a low-dose air-gap system. In our opinion, the slight increase in radiation dose burden is well motivated by the high quality of the radiographs produced. (orig.)

Reducing radiation doses to the breast, thyroid and gonads during diagnostic radiography

International Nuclear Information System (INIS)

Weatherburn, G.C.

1983-01-01

The measurement of doses to the gonads during radiography of the pelvis is discussed. Phantom measurements to estimate doses to the ovaries in antero-posterior (AP) and postero-anterior (PA) projections of the pelvis showed that the dose is 15% of the skin entry dose in the AP projection and 9% in the PA projection. The air gap technique and its applications in reducing radiation doses to the gonads, breast and thyroid is described. A summary of dose reduction factors for these radiosensitive organs achieved by modified radiographic techniques in radiography of the chest, pelvis, spine and skull is given. (U.K.)

Digital chest radiography: collimation and dose reduction

DEFF Research Database (Denmark)

Debess, Jeanne; Johnsen, Karen Kirstine; Vejle-Sørensen, Jens Kristian

,3 mAs and SID SID of 180 centimetres using a phantom and lithium fluoride thermo luminescence dosimeter (TLD). Dose to risk organs mamma, thyroid and colon are measured at different collimations with one-centimetre steps. TLD results are used to estimate dose reduction for different collimations...... at the conference. Conclusion: Collimation improvement in basic chest radiography can reduce the radiation to female patients at chest x-ray examinations....

Patient radiation dose in some dental radiography clinics in Khartoum, Sudan

International Nuclear Information System (INIS)

Mohamed, Aziza Hamed Abdelgadir

2016-01-01

Patient dose audit is an important tool for quality control and it is important for monitoring patient exposure. The DAP meter has proved to be an easy and accurate tool for patient dosimetry and for establishment of diagnostic reference levels in dental radiology. The objective of this study was measure patient dose in dental radiography in some dental radiography clinics in Khartoum. The study was performed in five dental clinics comprising six panoramic and six intraoral dental radiography devices in Khartoum state. The incident surface air kerma (k i ) and dose area product were measured for intraoral and panoramic dental examinations, respectively for digital and film imaging modalities. Incident surface air kerma (k i ) was measured using calibrated dose rate meter where dose area product were determined from dose width product (DWP) measured using 3 cc pencil type CT ionization chamber. For intraoral examinations, the maximum, average and minimum, (1.95, 1.48, and 1.24) mGy, (5.84, 4.54, and 3.6) mGy for digital and imaging, respectively. This result was lower in digital in traol and higher in film imaging. The result for panoramic examination calculated dose area product (DAP) mean value for adult and pediatric was (103, 70.42) mGy cm 2 , respectively, where the dose for digital imaging was highest in two centers, compared to previous study. Increased patient dose in intraoral dental radiography could partially be explained by the use of circular collimators. or intraoral x-ray equipment the downward trend in patient dose can only be continue, a through the adoption of digital imaging methods. Our results are relatively higher in digital panoramic dental examinations. It is important to point out that non of the dental units under study were covered by regular quality assurance programme.(Author)

Dose reduction using non lineal diffusion and smoothing filters in computed radiography

International Nuclear Information System (INIS)

Sánchez, M.G.; Juste, B.; Vidal, V.; Verdú, G.; Mayo, P.; Rodenas, F.

2014-01-01

The use of Computed Radiography (CR) into clinical practice has been followed by a high increase in the number of examinations performed and overdose cases in patients, especially children in pediatric applications. Computed radiographic images are corrupted by noise because either data acquisition or data transmission. The level of this inherent noise is related with the X-ray dose exposure: lower radiation exposure involves higher noise level. The main aim of this work is to reduce the noise present in a low radiation dose CR image in order to the get a CR image of the same quality as a higher radiation exposure image. In this work, we use a non lineal diffusion filtering method to reduce the noise level in a CR, this means that we are able to reduce the exposure, milliampere-second (mAs), and the dose absorbed by the patients. In order to get an optimal result, the diffusive filter is complemented with a smoothing filter with edge detection in order to preserve edges. Therefore, the proposed method consists in obtaining a good quality CR image for diagnostic purposes by selection of lower X-ray exposure jointly with a reduction of the noise. We conclude that a good solution to minimize the dose to patients, especially children in pediatric applications, in X-ray computed radiography consists in decreasing the mAs of the X-ray exposure and then processing the image with the proposed method. - Highlights: • We have investigated the techniques to obtain the image quality to make a confident diagnosis. • We have used diffusion and smoothing filter in order to reduce the exposure. • Reducing CR doses, especially in pediatric applications. • The new CR images allow medical researchers to analyze how low dose affects the patient diagnosis

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-12-15

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

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

International Nuclear Information System (INIS)

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

2009-01-01

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

The evaluation the magnitude radiation exposure dose rate in digital radiography room design

Science.gov (United States)

Dwiyanto, Agung; Setia Budi, Wahyu; Hardiman, Gagoek

2017-12-01

This study discusses the dose rate in digital radiography room, buit according to meet the provisions of KEMENKES No.1014 / Menkes / SK / XI / 2008 and Regulation of BAPETEN No. 8 / 2011. The provisions primary concern of radiation safety, not comfort, by considering the space design. There are five aspects to consider in designing the space: functionality, comfort, security, movement activities and aesthetics. However provisions only met three aspects of the design, which are a function, security and movement activity. Therefore, it is necessary to evaluate digital radiography room in terms of its ability to control external radiation exposure to be safe and comfortable The dose rate is measured by the range of primary and secondary radiation in the observation points by using Surveymeter. All data are obtained by the preliminary survey prior to the study. Furthermore, the review of digital radiography room is done based on architectural design theory. The dose rate for recommended improvement room is recalculated using the same method as the actual room with the help of computer modeling. The result of dose rate calculation at the inner and outer part of digital radiography observation room shows that in-room dose for a week at each measuring point exceeds the allowable dose limit both for staff and public. During a week of observation, the outdoor dose at some measuring points exceeds the dose limit set by the KEMENKES No.1014 / Menkes / SK / XI / 2008 and Regulation BEPETEN No 8/2011. Meanwhile, the result of dose rate calculation in the inner and outer part of the improved digital radiography room can meet the applicable regulations better.

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

International Nuclear Information System (INIS)

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

2004-01-01

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

Reference dose levels for dental periapical radiography in Chonnam Province

International Nuclear Information System (INIS)

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

2009-01-01

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

Reference dose levels for dental periapical radiography in Chonnam Province

Energy Technology Data Exchange (ETDEWEB)

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

2009-12-15

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

Radiographic examination protocol and patient dose in lateral cephalometric radiography in Korea

International Nuclear Information System (INIS)

Choi, Jin Woo

2010-01-01

To survey the radiographic examination protocol for lateral cephalometric radiographic examinations and to measure their patient doses in Korea and to compare the dose according to the size of hospital, the type of image receptor system, and the installation duration. The radiographic examination protocols (kVp, mA, and exposure time) for lateral cephalometric radiography were surveyed with 61 cephalometric radiographic equipments and their patient dose-area product (DAP) measured with a DAP meter (DIAMENTOR M4-KDK, PTW, Freiburg, Germany) for 51 cephalometric radiographic equipments. The radiographic examination protocols and patient doses were compared according to the size of hospital (university dental hospital, dental hospital, and dental clinic), the type of image receptor system (film-based, DR and CR type) and the installation duration, respectively. SPSS 12.0.1 for Windows (SPSS Inc., Chicago, USA) was used for independent t-test and ANOVA test. The average protocols were 77.0 kVp, 12.7 mA, 6.2 second for cephalometric radiography. The average patient dose (DAP) was 128.0 mGy cm2 and 3rd quartile dose (DAP) 161.1 mGy cm2 for cephalometric radiography for adult male. There was no statistically significant difference at average patient DAP according to the size of hospital, the type of image receptor system, and the installation duration, respectively. The average patient dose was 128.0 mGy cm2 and the third quartile patient dose 161.1 mGy cm2 for lateral cephalometric radiography for adult male in Korea.

Computed radiography versus mobile direct radiography for bedside chest radiographs: impact of dose on image quality and reader agreement

NARCIS (Netherlands)

de Boo, D. W.; Weber, M.; Deurloo, E. E.; Streekstra, G. J.; Freling, N. J.; Dongelmans, D. A.; Schaefer-Prokop, C. M.

2011-01-01

To asses the image quality and potential for dose reduction of mobile direct detector (DR) chest radiography as compared with computed radiography (CR) for intensive care unit (ICU) chest radiographs (CXR). Three groups of age-, weight- and disease-matched ICU patients (n=114 patients; 50 CXR per

Plain radiography procedures in Sudan: examination frequency and collective dose

International Nuclear Information System (INIS)

Musa, B. E. Y.

2010-12-01

According to the previous studies diagnostic examinations are the largest man-made source to collective dose (CED) in world. It was observed that, despite of the large number of medical x-ray installations in Sudan and in particular conventional x-ray procedures, studies aimed at estimating collective effective dose in diagnostic radiology were lacking. The purpose of this study was to estimate the annual frequency of plain radiography examinations and to estimate the annual collective effective dose to Sudanese population due to plain radiography examinations, selected by their high frequencies or their relatively high doses delivered to patient. To have an idea about the typical examinations frequencies, data were collected from a sample of ten hospitals in Khartoum. The collected data provided information about the x-ray machine manufacture, year of installation and frequency of some examinations per day. The annual collective doses from all medical examinations to the population are: 441, 166, 630, 544, 276, 525, 30, 9, 12 and 161 man Sv from abdomen AP, chest AP, pelvis, lumbar spine PA, lumbar spain PA, lumbar- sacral joints, Skull AP, Skull LAT, Skull PA and from others examination, respectively. The resulting annual collective effective dose was evaluated 2793 man Sv, with the largest contribution of pelvis and LS examinations and lowest contribution of skull examinations. Collective effective dose resulting from the use of plain radiography examinations in the Sudan is small compared with global results. But that dose not negate the need to conduct radiological surveys in frequent intervals to meet the increase of successive x-ray equipment to try to estimate and reduce the doses of patients and the public. (Author)

Evaluation of the Entrance Surface Dose (ESD and Radiation Dose to the Radiosensitive Organs in Pediatric Pelvic Radiography

Directory of Open Access Journals (Sweden)

Vahid Karami

2017-06-01

Full Text Available Background Patients' dosimetry is crucial in order to enhance radiation protection optimization and to deliver low radiation dose to the patients in a radiological procedure. The aim of this study was to assess the entrance surface dose (ESD and radiation dose to the radiosensitive organs in pediatric pelvic radiography. Materials and Methods The studied population included 98 pediatric patients of both genders referred to anteroposterior (AP projection of pelvic radiography. The radiation dose was directly measured using high radiosensitive cylindrical lithium fluoride thermo-luminescent dosimeters (TLD-GR200. Two TLDs were placed at the center point of the radiation field to measure the ESD of pelvis. Moreover for each patient, 2 TLDs were placed upon each eyelid, 2 TLDs upon each breast, 2 TLDs upon the surface anatomical position of the thyroid gland and finally 2 TLDs at the surface anatomical position of the gonads to measure the received dose. Results The ESD ± standard deviation for AP pelvic radiography was obtained 591.7±76 µGy. Statistically significant difference was obtained between organs located outside and inside of the radiation field with respect to dose received (P

Screen-film versus digital radiography of sacroiliac joints: Evaluation of image quality and dose to patients

International Nuclear Information System (INIS)

Jablanovic, D.; Ciraj-Bjelac, O.; Damjanov, N.; Seric, S.; Radak-Perovic, M.; Arandjic, D.; Maksimovic, R.

2013-01-01

The purpose of this paper is to evaluate the image quality and dose to patients in the radiography of sacroiliac joints and to perform a clinical comparative study of digital and conventional screen-film radiography. Routine radiography of sacroiliac joint was performed in 60 patients using digital and screen-film radiography. The visibility of five anatomical regions and the overall image quality were rated by experienced radiologists. Patient dose assessment in terms of entrance surface air kerma (ESAK) was performed. The digital system showed slightly improved visualisation of specific anatomical structures. Overall image quality was significantly better in the digital when compared with the screen-film imaging system. The average ESAK was 2.4 mGy in screen-film and 3.6 mGy in digital radiography. The digital radiography provided equal or better visibility of anatomical details and overall image quality, but on higher dose levels. Therefore, the practice on digital systems must be optimised. (authors)

Radiation dose to infants, children and adults in X-ray diagnostic radiology-in the case of plain radiography

International Nuclear Information System (INIS)

Aoyama, Takahiko; Koyama, Shuji; Yamauchi-Kawaura, Chiyo; Sugimoto, Naruto; Fujii, Keisuke; Kawasaki, Toshio

2012-01-01

The objective of this study was to evaluate radiation doses to infant, child and adult patients undergoing various types of plain radiography and to compare the doses among them. The doses were measured using newborn, 6-year-child and adult anthropomorphic phantoms, in which photodiode dosimeters were implanted at various tissue and organ positions. Measured doses were used to evaluate organ and effective doses. Organ doses obtained in various types of radiography were lower than 0.7 mGy for adults, 0.3 mGy for children and 0.2 mGy for infants, excepting lens dose of approximately 1 mGy in adult head radiography, where the doses for children and infants lowered to 1/2-1/3 of the doses for adults. Effective doses in various types of head radiography for adults, children and infants were in identical levels in a range of 5-30 μSv. In chest, abdomen and hip-joint radiography, effective doses of 0.02-0.11 mSv for children and 0.02-0.08 mSv for infants were identical to or in a fraction of the doses for adults of 0.06-0.15 mSv. In adult head and spinal radiography, effective doses by International Commission of Radiological Protection (ICRP) Publication 60 lowered respectively to 1/6-1/9 and 1/3-1/9 of the doses listed in United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) 2000. (author)

Radiation dose distribution monitoring at neutron radiography facility area, Nuclear Energy Unit, Malaysia

International Nuclear Information System (INIS)

Abdul Razak Daud

1995-01-01

One experiment was carried out to get the distribution of radiation doses at the neutron radiography facilities, Nuclear Energy Unit, Malaysia. The analysis was done to evaluate the safety level of the area. The analysis was used in neutron radiography work

Identifying high dose activities in industrial site radiography

International Nuclear Information System (INIS)

Heaton, B.

2000-01-01

Although the radiation doses received by industrial radiographers in the UK have progressively fallen over the last few years, with most now receiving less than 1 mSv/y, a few still receive, relative to the rest, much higher doses. As a percentage of all radiographers the number stays surprisingly constant from year to year. This paper describes a survey to identify the work causing these doses and suggest possible solutions. The UK Central Index of Dose Information was interrogated to identify the industrial radiography companies having staff (not necessarily the same person) with doses of greater than 5mSv/y in the last three years for which information was available. This was 15 in total. The people on the staff receiving these doses were identified and a questionnaire sent to the companies concerned requesting information about their work. A general questionnaire about the operation of the company was also included. With the agreement of the company these questionnaires were followed up by a visit to the company to interviews a number of the management and the radiographers if available. Both groups were generally very open about their problems and every discussion had a positive outcome. Several areas of work/reasons for the doses have been identified. These are: pipeline radiography, ultra sound radiographers working on nuclear reactors, complex plant work often with several teams in the area, inability to retreat from the wind out equipment due to height or access problems, site pressure to not follow the best practices and a lack of appreciation when a dose was being received or, alternatively, carelessness. Some o these problem areas are very difficult to resolve. However ways in which the Health and Safety can help influence the doses have been identified together with practical suggestions radiographers could adopt. These will be reported. (author)

Image quality and dose management in digital radiography: A new paradigm for optimisation

International Nuclear Information System (INIS)

Busch, H. P.; Faulkner, K.

2005-01-01

The advent of digital imaging in radiology, combined with the explosive growth of technology, has dramatically improved imaging techniques. This has led to the expansion of diagnostic capabilities, both in terms of the number of procedures and their scope. Throughout the world, film/ screen radiography systems are being rapidly replaced with digital systems. Many progressive medical institutions have acquired, or are considering the purchase of computed radiography systems with storage phosphor plates or direct digital radiography systems with flat panel detectors. However, unknown to some users, these devices offer a new paradigm of opportunity and challenges. Images can be obtained at a lower dose owing to the higher detective quantum efficiency (DQE). These fundamental differences in comparison to conventional film/screens necessitate the development of new strategies for dose and quality optimisations. A set of referral criteria based upon three dose levels is proposed. (authors)

Reference dose levels for dental panoramic radiography in Anyang City

International Nuclear Information System (INIS)

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

2009-01-01

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

Dose measurements in intraoral radiography using thermoluminescent dosimeters

Science.gov (United States)

Azorín, C.; Azorín, J.; Aguirre, F.; Rivera, T.

2015-01-01

The use of X-ray in medicine demands to expose the patient and the professional to the lowest radiation doses available in agreement with ALARA philosophy. The reference level for intraoral dental radiography is 7 mGy and, in Mexico, a number of examinations of this type are performed annually. It is considered that approximately 25% of all the X-rays examinations carried out in our country correspond to intraoral radiographies. In other hand, most of the intraoral X-ray equipment correspond to conventional radiological systems using film, which are developed as much manual as automatically. In this work the results of determining the doses received by the patients in intraoral radiological examinations made with different radiological systems using LiF:Mg,Cu,P+PTFE thermoluminescent dosimeters are presented. In some conventional radiological systems using film, when films are developed manual or automatically, incident kerma up to 10.61 ± 0.74 mGv were determined. These values exceed that reference level suggested by the IAEA and in the Mexican standards for intraoral examinations.

Dose measurements in intraoral radiography using thermoluminescent dosimeters

International Nuclear Information System (INIS)

Azorín, C; Rivera, T; Azorín, J; Aguirre, F

2015-01-01

The use of X-ray in medicine demands to expose the patient and the professional to the lowest radiation doses available in agreement with ALARA philosophy. The reference level for intraoral dental radiography is 7 mGy and, in Mexico, a number of examinations of this type are performed annually. It is considered that approximately 25% of all the X-rays examinations carried out in our country correspond to intraoral radiographies. In other hand, most of the intraoral X-ray equipment correspond to conventional radiological systems using film, which are developed as much manual as automatically. In this work the results of determining the doses received by the patients in intraoral radiological examinations made with different radiological systems using LiF:Mg,Cu,P+PTFE thermoluminescent dosimeters are presented. In some conventional radiological systems using film, when films are developed manual or automatically, incident kerma up to 10.61 ± 0.74 mGv were determined. These values exceed that reference level suggested by the IAEA and in the Mexican standards for intraoral examinations

Effect of Localizer Radiography Projection on Organ Dose at Chest CT with Automatic Tube Current Modulation.

Science.gov (United States)

Saltybaeva, Natalia; Krauss, Andreas; Alkadhi, Hatem

2017-03-01

Purpose To calculate the effect of localizer radiography projections to the total radiation dose, including both the dose from localizer radiography and that from subsequent chest computed tomography (CT) with tube current modulation (TCM). Materials and Methods An anthropomorphic phantom was scanned with 192-section CT without and with differently sized breast attachments. Chest CT with TCM was performed after one localizer radiographic examination with anteroposterior (AP) or posteroanterior (PA) projections. Dose distributions were obtained by means of Monte Carlo simulations based on acquired CT data. For Monte Carlo simulations of localizer radiography, the tube position was fixed at 0° and 180°; for chest CT, a spiral trajectory with TCM was used. The effect of tube start angles on dose distribution was investigated with Monte Carlo simulations by using TCM curves with fixed start angles (0°, 90°, and 180°). Total doses for lungs, heart, and breast were calculated as the sum of the dose from localizer radiography and CT. Image noise was defined as the standard deviation of attenuation measured in 14 circular regions of interest. The Wilcoxon signed rank test, paired t test, and Friedman analysis of variance were conducted to evaluate differences in noise, TCM curves, and organ doses, respectively. Results Organ doses from localizer radiography were lower when using a PA instead of an AP projection (P = .005). The use of a PA projection resulted in higher TCM values for chest CT (P chest CT. © RSNA, 2016 Online supplemental material is available for this article.

Computed radiography dose optimization in pediatric patients

International Nuclear Information System (INIS)

Juste, B.; Verdu, G.; Tortosa, R.; Villaescusa, J.I.

2008-01-01

Radiation dose reduction in pediatric X-ray imaging is especially important because of children radiation sensitivity. For any radiographic examination performed at a fixed radiographic tube potential, the patient absorbed dose is directly proportional to the value of milliampere-seconds (mAs) selected by the operator. Nevertheless, reducing X-ray exposure has the unavoidable disadvantage of increasing the quantum noise in the resultant image. The objective of this work is to identify the minimum tube current setting required for maintaining accurate examinations, to modify, if required, the daily protocols applied at La Fe de Valencia Universitary Hospital. To accomplish this goal, a noise addition software has been developed in order to study the diagnostic accuracy as a function of reducing dose by artificially increasing the image noise. The noise addition tool has been applied to several thorax images acquired from pediatric unit to simulate new lower dose radiographies and allow medical researchers to study how lower dose affects the patient pneumonia diagnosis. (author)

Occupational exposure in Greek industrial radiography laboratories (2004-2006) and comparison of doses with other industrial applications

International Nuclear Information System (INIS)

Tritakis, P.; Papadomarkaki, E.; Economides, S.; Carinou, E.; Hourdakis, C.; Kamenopoulou, V.; Dimitriou, P.

2008-01-01

Full text: In this study the Mean Annual Dose (MAD) of all industrial radiography workers in Greece for the time period 2004-2006 is evaluated and correlated to the practice and type of equipment used. All data used in this study come from the National Dose Registry Information System of the Greek Atomic Energy Commission. The present study constitutes the follow up of two previous studies, where a Dose Constraint (DC) for industrial radiography in Greece, equal to 4.0mSv was introduced for the first time. The introduction and systematic use of a dynamic DC value aims to optimize common working practices through a continuous decrease of occupational doses. In the current work a further decrease in the industrial radiography personnel doses is observed and the factors leading to this result are analyzed. Finally, the estimated MAD value for exposed workers in industrial radiography is compared to the ones corresponding to workers in other industrial applications involving the use of ionizing radiation

Application of a simple phantom in assessing the effects of dose reduction on image quality in chest radiography

International Nuclear Information System (INIS)

Egbe, N.O.; Heaton, B.; Sharp, P.F.

2010-01-01

Purpose: Firstly, to evaluate a commercial chest phantom incorporating a quasi anthropomorphic insert by comparing exposure measurements on the phantom with those of actual patients and, secondly, to assess the value of the phantom for image quality and dose optimisation. Methods: In the first part of the study entrance surface doses (ESD), Beam transmission (BT), and optical density (OD) were obtained for 77 chest radiography patients and compared with measurements made from exposures of the phantom using the respective patient exposure factors from chest examination. Differences were assessed with a student t-test, while the Pearson's linear correlation coefficient was used to test for any linear relationship. The second part assessed the applicability of the phantom to image quality studies by investigating the effect, on the clarity and detectability of lung lesions made from gelatine, of reducing patient dose below current dose levels. Clarity of linear objects of different dimensions was also studied. Lesion detectability and clarity was assessed by four observers. The possibility of extending dose reduction below current dose levels (D ref ) was assessed from comparison of doses that produced statistically significant differences in image quality from D ref . Results: Results show that, with the exception of entrance doses and beam transmission through the diaphragm (P > 0.05), differences in OD and beam transmission between patients and phantom were statistically significant (P ref produced significant changes in both clarity and detectability. Conclusion: Within limits posed by the observed differences, the phantom can be applied to image quality studies in diagnostic radiology.

Computer radiography - indirect digital radiography

International Nuclear Information System (INIS)

Jezierski, G.

2008-01-01

Implementation of the new European standards for industrial radiography with the use of storage phosphor imaging plates will result in the arousing of interest among numerous laboratories in non-destructive testing with application of the new method of testing to replace conventional radiography used so far, i.e. film radiography. Computer radiography is quite commonly used for medical radiography, where the fundamental problem consists in reduction of the radiation dose during the examination of a patient. However, it must be kept in mind that industrial applications have a little bit different requirements when compared with medical radiography. The article describes only new method for radiographic testing. (author)

Analysis of the spatial rates dose rates during dental panoramic radiography

Energy Technology Data Exchange (ETDEWEB)

Ko, Jong Kyung [Dept. of Radiation Safety Management Commission, Daegu Health College, Daegu (Korea, Republic of); Park, Myeong Hwan [Dept. of Radiologic Technology, Daegu Health College, Daegu (Korea, Republic of); Kim, Yong Min [Dept. of Radiological Science, Catholic University of Daegu, Daegu (Korea, Republic of)

2016-12-15

A dental panoramic radiography which usually uses low level X-rays is subject to the Nuclear Safety Act when it is installed for the purpose of education. This paper measures radiation dose and spatial dose rate by usage and thereby aims to verify the effectiveness of radiation safety equipment and provide basic information for radiation safety of radiation workers and students. After glass dosimeter (GD-352M) is attached to direct exposure area, the teeth, and indirect exposure area, the eye lens and the thyroid, on the dental radiography head phantom, these exposure areas are measured. Then, after dividing the horizontal into a 45°, it is separated into seven directions which all includes 30, 60, 90, 120 cm distance. The paper shows that the spatial dose rate is the highest at 30 cm and declines as the distance increases. At 30 cm, the spatial dose rate around the starting area of rotation is 3,840 μSv/h, which is four times higher than the lowest level 778 μSv/h. Furthermore, the spatial dose rate was 408 μSv/h on average at the distance of 60 cm where radiation workers can be located. From a conservative point of view, It is possible to avoid needless exposure to radiation for the purpose of education. However, in case that an unintended exposure to radiation happens within a radiation controlled area, it is still necessary to educate radiation safety. But according to the current Medical Service Act, in medical institutions, even if they are not installed, the equipment such as interlock are obliged by the Nuclear Safety Law, considering that the spatial dose rate of the educational dental panoramic radiography room is low. It seems to be excessive regulation.

MO-G-18A-01: Radiation Dose Reducing Strategies in CT, Fluoroscopy and Radiography

International Nuclear Information System (INIS)

Mahesh, M; Gingold, E; Jones, A

2014-01-01

Advances in medical x-ray imaging have provided significant benefits to patient care. According to NCRP 160, there are more than 400 million x-ray procedures performed annually in the United States alone that contributes to nearly half of all the radiation exposure to the US population. Similar growth trends in medical x-ray imaging are observed worldwide. Apparent increase in number of medical x-ray imaging procedures, new protocols and the associated radiation dose and risk has drawn considerable attention. This has led to a number of technological innovations such as tube current modulation, iterative reconstruction algorithms, dose alerts, dose displays, flat panel digital detectors, high efficient digital detectors, storage phosphor radiography, variable filters, etc. that are enabling users to acquire medical x-ray images at a much lower radiation dose. Along with these, there are number of radiation dose optimization strategies that users can adapt to effectively lower radiation dose in medical x-ray procedures. The main objectives of this SAM course are to provide information and how to implement the various radiation dose optimization strategies in CT, Fluoroscopy and Radiography. Learning Objectives: To update impact of technological advances on dose optimization in medical imaging. To identify radiation optimization strategies in computed tomography. To describe strategies for configuring fluoroscopic equipment that yields optimal images at reasonable radiation dose. To assess ways to configure digital radiography systems and recommend ways to improve image quality at optimal dose

The measurement of gonadal and bone-marrow doses from dental radiography

International Nuclear Information System (INIS)

Solomon, S.B.; Morris, N.D.

1980-06-01

The method of calculation of the radiation doses to the gonads and to the active bone marrow arising from dental radiography is described. The bone-marrow doses have been calculated using a computer model of X-ray depth doses within the skull for typical dental radiographic examinations as performed in Australia. The ovarian and testicular doses, as a percentage of skin dose have been determined experimentally. The dependence of the gonadal doses on X-ray tube voltage, face to cone distance and direction of the X-ray beam relative to the face is detailed

Skin and gonadal dose reduction during hip radiography of the bull

International Nuclear Information System (INIS)

Wood, A.K.W.; Blockey, deB.; Reynolds, K.M.; Leith, I.S.; Burns, P.A.

1979-01-01

Radiology is being used to an increasing extent in the clinical diagnosis of hip lameness in bulls. Consequent gonadal doses may have important implications in later breeding programmes. Skin and gonadal doses were recorded during hip radiography of 18 bulls. An additional 0.13 mm copper filtration reduced skin dose by more than one third, but had no effect on gonadal dose. The average radiation dose to the gonads was approximately halved by completely surrounding the scrotum with lead sheeting 0.95 mm in thickness. (author)

Low material budget floating strip Micromegas for ion transmission radiography

Energy Technology Data Exchange (ETDEWEB)

Bortfeldt, J., E-mail: jonathan.bortfeldt@cern.ch [LMU Munich, LS Schaile, Am Coulombwall 1, D-85748 Garching (Germany); Biebel, O.; Flierl, B.; Hertenberger, R.; Klitzner, F.; Lösel, Ph. [LMU Munich, LS Schaile, Am Coulombwall 1, D-85748 Garching (Germany); Magallanes, L. [LMU Munich, LS Parodi, Am Coulombwall 1, D-85748 Garching (Germany); University Hospital Heidelberg, Im Neuenheimer Feld 672, D-69120 Heidelberg (Germany); Müller, R. [LMU Munich, LS Schaile, Am Coulombwall 1, D-85748 Garching (Germany); Parodi, K. [LMU Munich, LS Parodi, Am Coulombwall 1, D-85748 Garching (Germany); Heidelberg Ion-Beam Therapy Center, Im Neuenheimer Feld 450, D-69120 Heidelberg (Germany); Schlüter, T. [LMU Munich, Excellence Cluster Universe, Boltzmannstr. 2, D-85748 Garching (Germany); Voss, B. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, D-64291 Darmstadt (Germany); Zibell, A. [JMU Würzburg, Sanderring 2, D-97070 Würzburg (Germany)

2017-02-11

Floating strip Micromegas are high-accuracy and discharge insensitive gaseous detectors, able to track single particles at fluxes of 7 MHz/cm{sup 2} with 100 μm resolution. We developed low-material-budget detectors with one-dimensional strip readout, suitable for tracking at highest particle rates as encountered in medical ion transmission radiography or inner tracker applications. Recently we additionally developed Kapton-based floating strip Micromegas with two-dimensional strip readout, featuring an overall thickness of 0.011 X{sub 0}. These detectors were tested in high-rate proton and carbon-ion beams at the tandem accelerator in Garching and the Heidelberg Ion-Beam Therapy Center, operated with an optimized Ne:CF{sub 4} gas mixture. By coupling the Micromegas detectors to a new scintillator based range detector, ion transmission radiographies of PMMA and tissue-equivalent phantoms were acquired. The range detector with 18 layers is read out via wavelength shifting fibers, coupled to a multi-anode photomultiplier. We present the performance of the Micromegas detectors with respect to timing and single plane track reconstruction using the μTPC method. We discuss the range resolution of the scintillator range telescope and present the image reconstruction capabilities of the combined system.

A dose monitoring system for dental radiography

Energy Technology Data Exchange (ETDEWEB)

Lee, Chena; Lee, Sam Sun; Kim, Jo Eun; Huh, Kyung Hoe; Yi, Woo Jin; Heo, Min Suk; Choi, Soon Chul [Dept. of Oral and Maxillofacial Radiology and Dental Research Institute, School of Dentistry, Seoul National University, Seoul (Korea, Republic of); Symkhampha, Khanthaly [Dept. of Oral and Maxillofacial Radiology, Department of Basic Science, Faculty of Dentistry, University of Health Sciences, Vientiane (Lao People' s Democratic Republic); Lee, Woo Jin [Dept. of Interdisciplinary Program in Radiation, Applied Life Sciences Major, College of Medicine, BK21, and Dental Research Institute, Seoul National University, Seoul (Korea, Republic of); Yeom, Heon Young [School of Computer Science Engineering, Seoul National University, Seoul (Korea, Republic of)

2016-06-15

The current study investigates the feasibility of a platform for a nationwide dose monitoring system for dental radiography. The essential elements for an unerring system are also assessed. An intraoral radiographic machine with 14 X-ray generators and five sensors, 45 panoramic radiographic machines, and 23 cone-beam computed tomography (CBCT) models used in Korean dental clinics were surveyed to investigate the type of dose report. A main server for storing the dose data from each radiographic machine was prepared. The dose report transfer pathways from the radiographic machine to the main sever were constructed. An effective dose calculation method was created based on the machine specifications and the exposure parameters of three intraoral radiographic machines, five panoramic radiographic machines, and four CBCTs. A viewing system was developed for both dentists and patients to view the calculated effective dose. Each procedure and the main server were integrated into one system. The dose data from each type of radiographic machine was successfully transferred to the main server and converted into an effective dose. The effective dose stored in the main server is automatically connected to a viewing program for dentist and patient access. A patient radiation dose monitoring system is feasible for dental clinics. Future research in cooperation with clinicians, industry, and radiologists is needed to ensure format convertibility for an efficient dose monitoring system to monitor unexpected radiation dose.

A dose monitoring system for dental radiography

International Nuclear Information System (INIS)

Lee, Chena; Lee, Sam Sun; Kim, Jo Eun; Huh, Kyung Hoe; Yi, Woo Jin; Heo, Min Suk; Choi, Soon Chul; Symkhampha, Khanthaly; Lee, Woo Jin; Yeom, Heon Young

2016-01-01

The current study investigates the feasibility of a platform for a nationwide dose monitoring system for dental radiography. The essential elements for an unerring system are also assessed. An intraoral radiographic machine with 14 X-ray generators and five sensors, 45 panoramic radiographic machines, and 23 cone-beam computed tomography (CBCT) models used in Korean dental clinics were surveyed to investigate the type of dose report. A main server for storing the dose data from each radiographic machine was prepared. The dose report transfer pathways from the radiographic machine to the main sever were constructed. An effective dose calculation method was created based on the machine specifications and the exposure parameters of three intraoral radiographic machines, five panoramic radiographic machines, and four CBCTs. A viewing system was developed for both dentists and patients to view the calculated effective dose. Each procedure and the main server were integrated into one system. The dose data from each type of radiographic machine was successfully transferred to the main server and converted into an effective dose. The effective dose stored in the main server is automatically connected to a viewing program for dentist and patient access. A patient radiation dose monitoring system is feasible for dental clinics. Future research in cooperation with clinicians, industry, and radiologists is needed to ensure format convertibility for an efficient dose monitoring system to monitor unexpected radiation dose

Comparison of radiation dose, workflow, patient comfort and financial break-even of standard digital radiography and a novel biplanar low-dose X-ray system for upright full-length lower limb and whole spine radiography

International Nuclear Information System (INIS)

Dietrich, Tobias J.; Pfirrmann, Christian W.A.; Pankalla, Katja; Buck, Florian M.; Schwab, Alexander

2013-01-01

To compare the radiation dose, workflow, patient comfort, and financial break-even of a standard digital radiography and a biplanar low-dose X-ray system. A standard digital radiography system (Ysio, Siemens Healthcare, Erlangen, Germany) was compared with a biplanar X-ray unit (EOS, EOS imaging, Paris, France) consisting of two X-ray tubes and slot-scanning detectors, arranged at an angle of 90 allowing simultaneous vertical biplanar linear scanning in the upright patient position. We compared data of standing full-length lower limb radiographs and whole spine radiographs of both X-ray systems. Dose-area product was significantly lower for radiographs of the biplanar X-ray system than for the standard digital radiography system (e.g. whole spine radiographs; standard digital radiography system: 392.2 ± 231.7 cGy*cm 2 versus biplanar X-ray system: 158.4 ± 103.8 cGy*cm 2 ). The mean examination time was significantly shorter for biplanar radiographs compared with standard digital radiographs (e.g. whole spine radiographs: 449 s vs 248 s). Patients' comfort regarding noise was significantly higher for the standard digital radiography system. The financial break-even point was 2,602 radiographs/year for the standard digital radiography system compared with 4,077 radiographs/year for the biplanar X-ray unit. The biplanar X-ray unit reduces radiation exposure and increases subjective noise exposure to patients. The biplanar X-ray unit demands a higher number of examinations per year for the financial break-even point, despite the lower labour cost per examination due to the shorter examination time. (orig.)

Digital chest radiography: an update on modern technology, dose containment and control of image quality

NARCIS (Netherlands)

Schaefer-Prokop, Cornelia; Neitzel, Ulrich; Venema, Henk W.; Uffmann, Martin; Prokop, Mathias

2008-01-01

The introduction of digital radiography not only has revolutionized communication between radiologists and clinicians, but also has improved image quality and allowed for further reduction of patient exposure. However, digital radiography also poses risks, such as unnoticed increases in patient dose

Computed and conventional chest radiography: a comparison of image quality and radiation dose

International Nuclear Information System (INIS)

Ramli, K.; Abdullah, B.J.J.; Ng, K-H.; Hussain, A.F.; Mahmud, R.

2005-01-01

The aim of this study was to compare the image quality and entrance skin dose (ESD) for film-screen and computed chest radiography. Analysis of the image quality and dose on chest radiography was carried out on a conventional X-ray unit using film-screen, storage phosphor plates and selenium drum direct chest radiography. For each receptor, ESD was measured in 60 patients using thermoluminescent dosemeters. Images were printed on 35 x 43 cm films. Image quality was assessed subjectively by evaluation of anatomic features and estimation of the image quality, following the guidelines established by the protocols of the Commission of the European Communities. There was no statistically significant difference noted between the computed and conventional images (Wilcoxon rank sum test, P>0.05). Imaging of the mediastinum and peripheral lung structures were better visualized with the storage phosphor and selenium drum technique than with the film-screen combination. The patients' mean ESD for chest radiography using the storage phosphor, film-screen combination and selenium drum was 0.20, 0.20 and 0.25 mGy, respectively, with no statistically significant difference with P > 0.05 (χ 2 tests) Copyright (2005) Blackwell Publishing Asia Pty Ltd

Comparison of Diagnostic Accuracy of Radiation Dose-Equivalent Radiography, Multidetector Computed Tomography and Cone Beam Computed Tomography for Fractures of Adult Cadaveric Wrists.

Science.gov (United States)

Neubauer, Jakob; Benndorf, Matthias; Reidelbach, Carolin; Krauß, Tobias; Lampert, Florian; Zajonc, Horst; Kotter, Elmar; Langer, Mathias; Fiebich, Martin; Goerke, Sebastian M

2016-01-01

To compare the diagnostic accuracy of radiography, to radiography equivalent dose multidetector computed tomography (RED-MDCT) and to radiography equivalent dose cone beam computed tomography (RED-CBCT) for wrist fractures. As study subjects we obtained 10 cadaveric human hands from body donors. Distal radius, distal ulna and carpal bones (n = 100) were artificially fractured in random order in a controlled experimental setting. We performed radiation dose equivalent radiography (settings as in standard clinical care), RED-MDCT in a 320 row MDCT with single shot mode and RED-CBCT in a device dedicated to musculoskeletal imaging. Three raters independently evaluated the resulting images for fractures and the level of confidence for each finding. Gold standard was evaluated by consensus reading of a high-dose MDCT. Pooled sensitivity was higher in RED-MDCT with 0.89 and RED-MDCT with 0.81 compared to radiography with 0.54 (P = radiography (P radiography. Readers are more confident in their reporting with the cross sectional modalities. Dose equivalent cross sectional computed tomography of the wrist could replace plain radiography for fracture diagnosis in the long run.

Dose reduction by x-ray beam filtration in screen-film radiography

International Nuclear Information System (INIS)

Koedooder, C.

1986-01-01

This thesis describes experimental and theoretical aspects of dose reduction by x-ray beam filtration in screen-film radiography. The thesis deals mainly with dose reduction under the constraint of constant image quality; an analytical approach is chosen. Therefore, part of the thesis deals with the development of an algorithm to calculate patient dose and exposure for different filter materials and different tube load conditions, under the constraint of constant contrast and constant optical density. (Auth.)

Dose Estimates for Site Radiography outside the Border to the Premises

Energy Technology Data Exchange (ETDEWEB)

Tanzi, C. P.; Eleveld, H.

2004-07-01

Radiography with X-ray generators or sealed radioactive sources (e.g. cobalt-60 and iridium-192) is a well-established non-destructive technique for the detection of internal flaws in welds and castings. The quality of the weld during the fabrication of pressure vessels, pipelines, storage tanks and other engineering structures can thus be verified. Often radiography is performed in an adequately shielded enclosure, but it may be necessary to perform it on location (site radiography). Paradoxically, if measurements are performed with other employees present, the main beam might be directed away towards the border of the premises in order to minimise the exposure of the workers but thus increasing the potential exposure to the population. In all cases a clearly marked enclosure has to be defined, to which neither non-radiological workers nor members of the public can have access. During a testing period, the maximum allowed dose rate at this enclosure is 10 microSv in one hour (only in exceptional cases 40 microSv) in the Netherlands. In addition, the Decree on radiation protection (in Dutch: {sup B}esluit stralingsbescherming{sup e}stablishes a further limit per location of 100 microSv per year, and the duty of reporting when the number of 3300 recordings at any one site is reached. This number is based on the assumption of a multifunctional individual dose of 0.03 microSv per recording at the enclosure. This multifunctional individual dose is defined as the dose received of an individual who lives in the vicinity of the source or location; this is a conservative approach considering the fact that the area around an industrial site is usually not intended to be residential area. However, for radiography in the field, skyshine might be underestimated, good collimation of the beam might not be seen as a priority, and the required monitoring may be difficult to guarantee along all of the enclosure. Also, there is an increasing availability of commercial portable X

Dose Estimates for Site Radiography outside the Border to the Premises

International Nuclear Information System (INIS)

Tanzi, C. P.; Eleveld, H.

2004-01-01

Radiography with X-ray generators or sealed radioactive sources (e.g. cobalt-60 and iridium-192) is a well-established non-destructive technique for the detection of internal flaws in welds and castings. The quality of the weld during the fabrication of pressure vessels, pipelines, storage tanks and other engineering structures can thus be verified. Often radiography is performed in an adequately shielded enclosure, but it may be necessary to perform it on location (site radiography). Paradoxically, if measurements are performed with other employees present, the main beam might be directed away towards the border of the premises in order to minimise the exposure of the workers but thus increasing the potential exposure to the population. In all cases a clearly marked enclosure has to be defined, to which neither non-radiological workers nor members of the public can have access. During a testing period, the maximum allowed dose rate at this enclosure is 10 microSv in one hour (only in exceptional cases 40 microSv) in the Netherlands. In addition, the Decree on radiation protection (in Dutch: B esluit stralingsbescherming e stablishes a further limit per location of 100 microSv per year, and the duty of reporting when the number of 3300 recordings at any one site is reached. This number is based on the assumption of a multifunctional individual dose of 0.03 microSv per recording at the enclosure. This multifunctional individual dose is defined as the dose received of an individual who lives in the vicinity of the source or location; this is a conservative approach considering the fact that the area around an industrial site is usually not intended to be residential area. However, for radiography in the field, skyshine might be underestimated, good collimation of the beam might not be seen as a priority, and the required monitoring may be difficult to guarantee along all of the enclosure. Also, there is an increasing availability of commercial portable X-ray units

SU-E-I-15: Comparison of Radiation Dose for Radiography and EOS in Adolescent Scoliosis Patients

Energy Technology Data Exchange (ETDEWEB)

Schueler, B; Walz-Flannigan, A [Mayo Clinic, Rochester, MN (United States)

2014-06-01

Purpose: To estimate patient radiation dose for whole spine imaging using EOS, a new biplanar slot-scanning radiographic system and compare with standard scoliosis radiography. Methods: The EOS imaging system (EOS Imaging, Paris, France) consists of two orthogonal x-ray fan beams which simultaneously acquire frontal and lateral projection images of a standing patient. The patient entrance skin air kerma was measured for each projection image using manufacturer-recommended exposure parameters for spine imaging. Organ and effective doses were estimated using a commercially-available Monte Carlo simulation program (PCXMC, STUK, Radiation and Nuclear Safety Authority, Helsinki, Finland) for a 15 year old mathematical phantom model. These results were compared to organ and effective dose estimated for scoliosis radiography using computed radiography (CR) with standard exposure parameters obtained from a survey of pediatric radiographic projections. Results: The entrance skin air kerma for EOS was found to be 0.18 mGy and 0.33 mGy for posterior-anterior (PA) and lateral projections, respectively. This compares to 0.76 mGy and 1.4 mGy for CR, PA and lateral projections. Effective dose for EOS (PA and lateral projections combined) is 0.19 mSv compared to 0.51 mSv for CR. Conclusion: The EOS slot-scanning radiographic system allows for reduced patient radiation dose in scoliosis patients as compared to standard CR radiography.

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

Science.gov (United States)

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

2014-11-01

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

A Monte-Carlo simulation framework for joint optimisation of image quality and patient dose in digital paediatric radiography

International Nuclear Information System (INIS)

Menser, Bernd; Manke, Dirk; Mentrup, Detlef; Neitzel, Ulrich

2016-01-01

In paediatric radiography, according to the as low as reasonably achievable (ALARA) principle, the imaging task should be performed with the lowest possible radiation dose. This paper describes a Monte-Carlo simulation framework for dose optimisation of imaging parameters in digital paediatric radiography. Patient models with high spatial resolution and organ segmentation enable the simultaneous evaluation of image quality and patient dose on the same simulated radiographic examination. The accuracy of the image simulation is analysed by comparing simulated and acquired images of technical phantoms. As a first application example, the framework is applied to optimise tube voltage and pre-filtration in newborn chest radiography. At equal patient dose, the highest CNR is obtained with low-kV settings in combination with copper filtration. (authors)

The effect of increased body mass index on patient dose in paediatric radiography

Energy Technology Data Exchange (ETDEWEB)

Ladia, Arsenoi P., E-mail: arsenoh@gmail.com; Skiadopoulos, Spyros G., E-mail: skiado@upatras.gr; Karahaliou, Anna N., E-mail: akarahaliou@upatras.gr; Messaris, Gerasimos A.T., E-mail: messaris@upatras.gr; Delis, Harry B., E-mail: hdelis@gmail.com; Panayiotakis, George S., E-mail: panayiot@upatras.gr

2016-10-15

Radiation protection is of particular importance in paediatric radiology. In this study, the influence of increased body mass index (BMI) in radiation dose and associated risk was investigated for paediatric patients aged 5–6.5 years, undergoing chest (64 patients) or abdomen (64 patients) radiography. Patients were categorized into normal and overweight, according to the BMI classification scheme. Entrance surface dose (ESD), organ dose, effective dose (ED) and risk of exposure induced cancer death (REID) were calculated using the Monte Carlo based code PCXMC 2.0. Statistically significant increase in patient radiation dose and REID was obtained for overweight patients as compared to normal ones, in both chest and abdomen examinations (Wilcoxon singed-rank test for paired data, p < 0.001). The percentage increase in overweight as compared to normal patients of ESD, organ dose (maximum value), ED and REID was 13.6%, 24.4%, 18.9% and 20.6%, respectively, in case of chest radiographs. Corresponding values in case of abdomen radiographs were 15.0%, 24.7%, 21.8% and 19.8%, respectively. An increased BMI results in increased patient radiation dose in chest and abdomen paediatric radiography.

Patient's dose assessment during sinus X-rays radiography at 'Hopital du Point G'

International Nuclear Information System (INIS)

Sidibe, S.; Sacko, B.Y.; Doucoure, M.; Traore, B.; Traore, I.

2001-01-01

Objective: To evaluate the patient's X-rays dose during head radiography for sinusitis; To precise the influence of source-image distance on the patient's dose. Material and method: From May 1997 to January 1999, 83 patients with clinical suspicious sinusitis have been included in this study. Skull radiography in 3 positions (posterior, lateral and Blondeau view) have been achieved for each patient on 24x30 centimeters size films. These radiographies were realised on a Diagnost 7 Masio Philip X-rays machine. Three TLD dosimeters were pasted against every patient target organs (thyroid, right and left eyes). The source-image distance (SID) was 100 centimeters for the first group (35 patients) and 125 centimeters for the second group (48 patients). The selected parameters (high voltage and charge) were as follows: Skull postero-anterior view: 65 to 85 kV, 80 mAs; Skull lateral view: 60 to 75 kV, 80 mAs; Blondeau view (paranasal sinuses): 90 to 95 kV, 100 mAs. Results: All the radiographies were analysed by the same radiologist who didn't know the SID. All the films were of good quality. The patient's dose in millisievert for each target organ were: Group I (SID = 100 cm): Left eye 3,2 (+ ou - 0,66); Right eye 3, 0 (+ ou - 0,82); Thyroid 0,62 (+ ou - 0,09). Group II (SID = 125 cm): Left eye 1,9 (+ ou - 0,48); Right eye 1, 86 (+ ou - 0,50); Thyroid 0,39 (+ ou - 0,08). In conclusion, the increase of SID from 100 to 125 centimeters allows patient's dose reduction by a factor of 1.6 without the alteration of the films quality, hence the reliability of the diagnosis. (author)

Estimation of exposed radiation dose in radiography of the chest. Mainly on the dose at health examination on automobiles

International Nuclear Information System (INIS)

Suzuki, Shoichi; Oda, Akiko; Ohkura, Masaki

1998-01-01

The exposure doses in radiography and photofluorography of the chest at health examination on automobiles were estimated and compared with those using other hospital equipments. The tube voltage, effective energy and half value layer under ordinary conditions for radiography and fluorography were measured by KYOKKO model 100 X-ray analyzer and output pulse shape was confirmed by the fluorometer (TOREKEY-1001 C). The dose at the body surface was measured by the ionization chambers (VICTOREEN RADCON 500 and 30-330) which had been equipped in the WAC chest phantom (JIS Z 4915, Kyoto Kagaku). Nine automobiles of 3 facilities were used, of which X-ray generating apparatuses of either condenser or inverter type were manufactured by Hitachi (5 machines), Toshiba (1) and Shimadzu (3). The examined apparatuses not for the automobile were Toshiba-20 and Hitachi SIRIUS-100 portable ones and Hitachi DH-1520 TM high-voltage one. The effective energy was found dependent on the tube voltage (100-130 kV) and X-ray generating system (35.1-54.37 keV in the condenser type and 41.1-43.9 keV in the inverter type). Pulse shape analysis revealed that the pulse height and area under the pulse height-time curve were larger in the inverter system. The mean doses in photofluorography and radiography on automobiles were 0.525 and 0.297 mGy, respectively. The mean dose of 0.61 mGy in radiography at home with the portable apparatus was the highest even when compared with that of 0.525 mGy for fluorography on the automobile. Thus, the inverter system on the car can guarantee the level of 0.4 mGy defined by IAEA guideline (Safety series No. 115, 1996). (K.H.)

Dental radiography

International Nuclear Information System (INIS)

Shekhdar, J.

1993-01-01

Dental radiography must comply with the same regulations with which conventional radiography complies. Radiation doses to individual patients are low but, because of the large number of patients X-rayed, the collective dose to the population is not negligible. Care in siting and regular maintenance of the equipment will reduce doses to both staff and patients. To produce X-ray films with a good image quality using a low radiation dose requires attention to film processing; this is often a neglected area. (Author)

Diagnostic accuracy of low-dose CT compared with abdominal radiography in non-traumatic acute abdominal pain: prospective study and systematic review.

Science.gov (United States)

Alshamari, Muhammed; Norrman, Eva; Geijer, Mats; Jansson, Kjell; Geijer, Håkan

2016-06-01

Abdominal radiography is frequently used in acute abdominal non-traumatic pain despite the availability of more advanced diagnostic modalities. This study evaluates the diagnostic accuracy of low-dose CT compared with abdominal radiography, at similar radiation dose levels. Fifty-eight patients were imaged with both methods and were reviewed independently by three radiologists. The reference standard was obtained from the diagnosis in medical records. Sensitivity and specificity were calculated. A systematic review was performed after a literature search, finding a total of six relevant studies including the present. Overall sensitivity with 95 % CI for CT was 75 % (66-83 %) and 46 % (37-56 %) for radiography. Specificity was 87 % (77-94 %) for both methods. In the systematic review the overall sensitivity for CT varied between 75 and 96 % with specificity from 83 to 95 % while the overall sensitivity for abdominal radiography varied between 30 and 77 % with specificity 75 to 88 %. Based on the current study and available evidence, low-dose CT has higher diagnostic accuracy than abdominal radiography and it should, where logistically possible, replace abdominal radiography in the workup of adult patients with acute non-traumatic abdominal pain. • Low-dose CT has a higher diagnostic accuracy than radiography. • A systematic review shows that CT has better diagnostic accuracy than radiography. • Radiography has no place in the workup of acute non-traumatic abdominal pain.

Management of pediatric radiation dose using Fuji computed radiography

International Nuclear Information System (INIS)

MacCutcheon, D.W.

2004-01-01

This paper describes the technical details of Fuji Computed Radiography (FCR) and its use as it relates to managing pediatric dose for X-ray examinations. Since its introduction in 1983, Fuji (Fuji Photo Film Co., Ltd.) has developed an extensive set of menu selections with default processing algorithms and corresponding display processing parameters modified for all pediatric exam types. Continued development of imaging plate technology, FCR reader design and image processing have all contributed to improving image quality and creating the opportunity to lower the dose required for pediatric exams. Fuji continues to advance CR and electronic imaging technologies; some of these developments, that may enable lower dose examinations for pediatric imaging in the future, are also described in this paper. (orig.)

Evaluation of occupational exposure in intraoral radiography; Avaliacao da dose ocupacional em radiografia intraoral

Energy Technology Data Exchange (ETDEWEB)

Miguel, Cristiano; Barros, Frieda S.; Rocha, Anna S.P.S.; Godoi, Walmor C., E-mail: miguel_cristianoch@yahoo.com.br, E-mail: saicla@utfpr.edu.br, E-mail: annarocha@yahoo.com, E-mail: walmor.godoi@gmail.com [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Tilly Junior, Joao G., E-mail: joao.tilly@derax.com.br [Universidade Federal do Parana (HC/UFPR), Curitiba, PR (Brazil). Hospital das Clinicas

2014-07-01

The intraoral radiography is widely performed in the dental office due to low cost and agility. The doses in intraoral radiology are considered low, however it is known that doses below the threshold for deterministic radiation has the potential to induce stochastic effects. An intraoral radiography has a risk of inducing fatal cancer or serious in order of 1:10,000,000. Besides the patient, the dentist may also be being exposed to radiation during the work with the radiographics practices. The bibliographies demonstrates the lack of information on radiation protection of dentists, however, the occupational dose reduction was observed in radiology over the past 14 years. This work aims to evaluate the effective dose of radiation to which workers can be exposed dentists in dental offices to perform intraoral radiographs. In this context, a study was be conducted between June 2013 and May 2014 with 44 professionals in Curitiba city. For each dentist was given a personal dosimeter to be used for 30 days. During this period, the number of radiographies and the length of the cable triggers of the X-ray equipment was registered and, the dosimeter´s dose was read. It was observed that the cables triggers meet regulatory standards and allow dentists to get the mean minimum distance of two meters from the radiation source in 93% of cases. Through analysis of the doses, it was concluded that occupational exposures of these workers are within the recommended threshold by regulatory 453/1998 of the Ministry of Health from Brazil. (author)

Computed radiography versus mobile direct radiography for bedside chest radiographs: Impact of dose on image quality and reader agreement

International Nuclear Information System (INIS)

De Boo, D.W.; Weber, M.; Deurloo, E.E.; Streekstra, G.J.; Freling, N.J.; Dongelmans, D.A.; Schaefer-Prokop, C.M.

2011-01-01

Aim: To asses the image quality and potential for dose reduction of mobile direct detector (DR) chest radiography as compared with computed radiography (CR) for intensive care unit (ICU) chest radiographs (CXR). Methods and materials: Three groups of age-, weight- and disease-matched ICU patients (n = 114 patients; 50 CXR per acquisition technique) underwent clinically indicated bedside CXR obtained with either CR (single read-out powder plates) or mobile DR (GOS-TFT detectors) at identical or 50% reduced dose (DR 50% ). Delineation of anatomic structures and devices used for patient monitoring, overall image quality and disease were scored by four readers. In 12 patients pairs of follow-up CR and DR images were available, and in 15 patients pairs of CR and DR 50% images were available. In these pairs the overall image quality was also compared side-by-side. Results: Delineation of anatomy in the mediastinum was scored better with DR or DR 50% than with CR. Devices used for patient monitoring were seen best with DR, with DR 50% being superior to CR. In the side-by-side comparison, the overall image quality of DR and DR 50% was rated better than CR in 96% (46/48) and 87% (52/60), respectively. Inter-observer agreement for the assessment of pathology was fair for CR and DR 50% (κ = 0.33 and κ = 0.39, respectively) and moderate for DR (κ = 0.48). Conclusion: Mobile DR units offer better image quality than CR for bedside chest radiography and allow for 50% dose reduction. Inter-observer agreement increases with image quality and is superior with DR, while DR 50% and CR are comparable.

Radiation Effects in Paediatric radiography

International Nuclear Information System (INIS)

Mutwasi, O.

2006-01-01

Diagnostic imaging has evolved from single technique to a field which we have a choice from many modalities. Some without radiation. Radiation producing modalities include plain films (low dose), Fluoroscopy (mid range dose), Computed tomography (high dose). Radiography dose can significantly be influenced in plain radiography by varying speed of screens, cassette construction and type of radiography. E.g. digital or computed. In computed or digital radiography we are no longer able to tell h igh dose b y the quality of images. The final image is by great extend a product of post processing algorithms. It's for this reasons that the basic understanding of the sensitivity and specifying of various types of examinations and of specifically radiation effects is mandatory for a paediatric imager

Effective dose efficiency: an application-specific metric of quality and dose for digital radiography

Energy Technology Data Exchange (ETDEWEB)

Samei, Ehsan; Ranger, Nicole T; Dobbins, James T III; Ravin, Carl E, E-mail: samei@duke.edu [Carl E Ravin Advanced Imaging Laboratories, Department of Radiology (United States)

2011-08-21

The detective quantum efficiency (DQE) and the effective DQE (eDQE) are relevant metrics of image quality for digital radiography detectors and systems, respectively. The current study further extends the eDQE methodology to technique optimization using a new metric of the effective dose efficiency (eDE), reflecting both the image quality as well as the effective dose (ED) attributes of the imaging system. Using phantoms representing pediatric, adult and large adult body habitus, image quality measurements were made at 80, 100, 120 and 140 kVp using the standard eDQE protocol and exposures. ED was computed using Monte Carlo methods. The eDE was then computed as a ratio of image quality to ED for each of the phantom/spectral conditions. The eDQE and eDE results showed the same trends across tube potential with 80 kVp yielding the highest values and 120 kVp yielding the lowest. The eDE results for the pediatric phantom were markedly lower than the results for the adult phantom at spatial frequencies lower than 1.2-1.7 mm{sup -1}, primarily due to a correspondingly higher value of ED per entrance exposure. The relative performance for the adult and large adult phantoms was generally comparable but affected by kVps. The eDE results for the large adult configuration were lower than the eDE results for the adult phantom, across all spatial frequencies (120 and 140 kVp) and at spatial frequencies greater than 1.0 mm{sup -1} (80 and 100 kVp). Demonstrated for chest radiography, the eDE shows promise as an application-specific metric of imaging performance, reflective of body habitus and radiographic technique, with utility for radiography protocol assessment and optimization.

Evaluation of organ dose and estimation of risk due to the abdominal region radiography in Indian adults

International Nuclear Information System (INIS)

Kumaresan, M.; Chaubey, Ajay; Kantharia, Surita; Karira, V.; Kumar, Rajesh; Biju, K.; Rao, B.S.

2006-01-01

Organ dose, risk of carcinogenesis and genetic effect due to the abdominal region radiography in Indian adult with the help of Monte-Carlo MCNP code by measuring the entrance skin dose by LiF: Mg, Cu, P TL phosphor and the risk coefficients provided by ICRP 60 were estimated. The entrance skin dose for abdominal region radiography was ranges from 2.75 mSv to 18.88 mSv while average entrance skin dose was 8.3 mSv. The bladder, testes and ovary are the important organ those are getting higher dose. The maximum dose for testes, ovary and bladder is 5.37 mSv, 1.45 mSv and 4.74 mSv respectively. The frequency of occurrence of fatal cancers and serious genetic disorders as a consequence of abdominal region radiography ranges from 0.1 to 38.8 risk/10 6 of fatal cancer. Although the estimated risks are small but cannot be neglected. It is important to avoid unnecessary repetitions and also to carry out proper quality assurance tests on the equipment and in the long run it will help reduce the risks and maximize the benefits of radiodiagnosis. These studies may lead to setting up of national reference levels for the diagnostic procedures India. (author)

Evaluation of surface radiation dose to the thyroid gland and the gonads during routine full-mouth intraoral periapical and maxillary occlusal radiography

Directory of Open Access Journals (Sweden)

Soheyl Sheikh

2010-01-01

Full Text Available Aim: The quantitative aspects of radiation doses to critical organs can help the dental professionals to take the necessary radiation protective measures as deemed necessary and can help the general public to allay radiation exposure fear in dental radiography, if any. Our study determines the surface radiation dose to thyroid and gonads in full-mouth intraoral periapical (IOPA and maxillary occlusal radiography.Materials and Methods: A total number of 120 subjects participated in the study. The surface radiation dose was estimated to the thyroid gland and the gonads in full-mouth IOPA radiography using 10 IOPA (E speed films and in maxillary occlusal radiography. The measurements were calculated using a digital pocket dosimeter (PD-4507.Results: The average dose at the thyroid gland level during full-mouth intraoral and maxillary occlusal radiography was estimated to be 10.93 mRads (1.093 Χ 10 -2 mGy and 0.4 mRads (4.0 Χ 10 -2 mGy, respectively. The average surface radiation dose at the gonadal region during a full mouth intraoral and maxillary occlusal radiography was estimated to be 1.5 mRads (1.5 Χ 10 -2 mGy and 0.15 mRads (1.5 Χ 10 -3 mGy, respectively. Conclusion: Our results suggest that although the radiation exposure doses to critical organs namely thyroid and gonads is within the safe limits still precautionary measures for these organs are advocated.

Bone X-Ray (Radiography)

Medline Plus

Full Text Available ... Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small dose ... limitations of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is ...

Industrial radiography

International Nuclear Information System (INIS)

1994-01-01

This Health and Safety Executive Information Sheet on industrial radiography aims to inform directors and managers of industrial radiography companies on the safety precautions necessary to ensure that their personnel do not exceed dose guidelines for exposure to ionizing radiation. The Ionising Radiations Regulations 1985 (IRR85) require that exposure doses for radiographers are kept as low reasonably practicable. Equipment maintenance, and the employment of proper emergency procedures will help to ensure personnel safety. (UK)

An overview of digital radiography

International Nuclear Information System (INIS)

Aweligiba, S. A.

2013-04-01

The medical application of radiography has gained wider study since diagnostic radiology plays a very important role in modern medicine for fast diagnosis and therapy. Digital radiography is a relatively new technology that promises greater accuracy, lesser dose and better manipulation of patient radiology images in hospitals. In this study, a general discussion on digital radiography has been presented. The presentation focuses on the optimisation of doses to patients in the medical application of digital radiography, quality control and quality assurance. A brief presentation on performance indicators in digital radiography has also been presented. The advantages of digital radiography over the conventional film/screen system have been elaborated and its limitations are also outlined. (author)

Diagnostic accuracy of low-dose CT compared with abdominal radiography in non-traumatic acute abdominal pain: prospective study and systematic review

International Nuclear Information System (INIS)

Alshamari, Muhammed; Geijer, Haakan; Norrman, Eva; Geijer, Mats; Jansson, Kjell

2016-01-01

Abdominal radiography is frequently used in acute abdominal non-traumatic pain despite the availability of more advanced diagnostic modalities. This study evaluates the diagnostic accuracy of low-dose CT compared with abdominal radiography, at similar radiation dose levels. Fifty-eight patients were imaged with both methods and were reviewed independently by three radiologists. The reference standard was obtained from the diagnosis in medical records. Sensitivity and specificity were calculated. A systematic review was performed after a literature search, finding a total of six relevant studies including the present. Overall sensitivity with 95 % CI for CT was 75 % (66-83 %) and 46 % (37-56 %) for radiography. Specificity was 87 % (77-94 %) for both methods. In the systematic review the overall sensitivity for CT varied between 75 and 96 % with specificity from 83 to 95 % while the overall sensitivity for abdominal radiography varied between 30 and 77 % with specificity 75 to 88 %. Based on the current study and available evidence, low-dose CT has higher diagnostic accuracy than abdominal radiography and it should, where logistically possible, replace abdominal radiography in the workup of adult patients with acute non-traumatic abdominal pain. (orig.)

Diagnostic accuracy of low-dose CT compared with abdominal radiography in non-traumatic acute abdominal pain: prospective study and systematic review

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Alshamari, Muhammed; Geijer, Haakan [Oerebro University, Department of Radiology, Faculty of Medicine and Health, Oerebro (Sweden); Norrman, Eva [Oerebro University, Department of Medical Physics, Faculty of Medicine and Health, Oerebro (Sweden); Geijer, Mats [Lund University and Skaane University Hospital, Department of Medical Imaging and Physiology, Lund (Sweden); Jansson, Kjell [Oerebro University, Department of Surgery, Faculty of Medicine and Health, Oerebro (Sweden)

2016-06-15

Abdominal radiography is frequently used in acute abdominal non-traumatic pain despite the availability of more advanced diagnostic modalities. This study evaluates the diagnostic accuracy of low-dose CT compared with abdominal radiography, at similar radiation dose levels. Fifty-eight patients were imaged with both methods and were reviewed independently by three radiologists. The reference standard was obtained from the diagnosis in medical records. Sensitivity and specificity were calculated. A systematic review was performed after a literature search, finding a total of six relevant studies including the present. Overall sensitivity with 95 % CI for CT was 75 % (66-83 %) and 46 % (37-56 %) for radiography. Specificity was 87 % (77-94 %) for both methods. In the systematic review the overall sensitivity for CT varied between 75 and 96 % with specificity from 83 to 95 % while the overall sensitivity for abdominal radiography varied between 30 and 77 % with specificity 75 to 88 %. Based on the current study and available evidence, low-dose CT has higher diagnostic accuracy than abdominal radiography and it should, where logistically possible, replace abdominal radiography in the workup of adult patients with acute non-traumatic abdominal pain. (orig.)

Improvement of the clinical use of computed radiography for mobile chest imaging: Image quality and patient dose

Science.gov (United States)

Rill, Lynn Neitzey

Chest radiography is technically difficult because of the wide variation of tissue attenuations in the chest and limitations of screen-film systems. Mobile chest radiography, performed bedside on hospital inpatients, presents additional difficulties due to geometrical and equipment limitations inherent to mobile x-ray procedures and the severity of illness in patients. Computed radiography (CR) offers a new approach for mobile chest radiography by utilizing a photostimulable phosphor. Photostimulable phosphors are more efficient in absorbing lower-energy x-rays than standard intensifying screens and overcome some image quality limitations of mobile chest imaging, particularly because of the inherent latitude. This study evaluated changes in imaging parameters for CR to take advantage of differences between CR and screen-film radiography. Two chest phantoms, made of acrylic and aluminum, simulated x-ray attenuation for average-sized and large- sized adult chests. The phantoms contained regions representing the lungs, heart and subdiaphragm. Acrylic and aluminum disks (1.9 cm diameter) were positioned in the chest regions to make signal-to-noise ratio (SNR) measurements for different combinations of imaging parameters. Disk thicknesses (contrast) were determined from disk visibility. Effective dose to the phantom was also measured for technique combinations. The results indicated that using an anti-scatter grid and lowering x- ray tube potential improved the SNR significantly; however, the dose to the phantom also increased. An evaluation was performed to examine the clinical applicability of the observed improvements in SNR. Parameter adjustments that improved phantom SNRs by more than 50% resulted in perceived image quality improvements in the lung region of clinical mobile chest radiographs. Parameters that produced smaller improvements in SNR had no apparent effect on clinical image quality. Based on this study, it is recommended that a 3:1 grid be used for

Evaluation on organ dose and image quality of lumber spine radiography using glass dosimeter

International Nuclear Information System (INIS)

Kim, Jae Kyeom; Kim, Jeong Koo

2016-01-01

The purpose of this study was to provide resources for medical exposure reduction through evaluation of organ dose and image resolution for lumbar spine around according to the size of the collimator in DR system. The size of the collimator were varied from 8″×17″ to 14″×17″ by 1″ in AP and lateral projection for the lumbar spine radiography with RANDO phantom. The organ dose measured for liver, stomach, pancreas, kidney and gonad by the glass dosimeter. The image resolution was analyzed using the Image J program. The organ dose of around lumbar spine were reduced as the size of the collimator is decreased in AP projection. There were no significant changes decreasing rate whenever the size of the collimator were reduced 1″ in the gonad. The organ dose showed higher on liver and kidney near the surface in lateral projection. There were decreasing rate of less than 5% in liver and kidney, but decreasing rate was 24.34% in the gonad whenever the size of the collimator were reduced 1″. Organ dose difference for internal and external of collimator measured 549.8 μGy in the liver and 264.6 μGy in the stomach. There were no significant changes organ dose difference that measured 1,135.1 μG in the gonad. Image Quality made no difference because SNR and PSNR were over than 30 dB when the collimator size is less than 9″×17″ on AP projection and 10″×17″ on lateral projection. Therefore, we are considered that the recommendations criterion for control of collimator were suggested in order to reduce unnecessary X-ray exposure and to obtain good image quality because lumbar spine radiography contains a lot of peripheral organs rather than other area radiography

Options for radiation dose optimisation in pelvic digital radiography: A phantom study

International Nuclear Information System (INIS)

Manning-Stanley, Anthony S.; Ward, Anthony J.; England, Andrew

2012-01-01

Purpose: To investigate the effects of phantom orientation and AEC chamber selection on radiation dose and image quality (IQ) for digital radiography (DR) examinations of the pelvis. Methods: A phantom study was conducted using a DR detector, utilising all AEC chamber combinations. Current recommended orientation (Cr-AEC) was with the outer AEC chambers cranially orientated. mAs (given), source-to-skin distance and kV p data facilitated entrance surface dose and effective dose calculations. Six anatomical areas were blindly graded by two observers (3-point scale) for IQ. Statistical differences in radiation dose were determined using the paired Student’s t-test. IQ data was analysed for inter-observer variability (ICC) and statistical differences (Wilcoxon test). Results: Switching phantom orientation (caudally orientated outer AEC chambers: Ca-AEC) reduced mean radiation dose by 36.8%, (p < 0.001). A minor reduction in median IQ (15.5 vs. 15) was seen (p < 0.001). One Ca-AEC orientated image (1.6%) had all anatomical areas graded ‘inadequate’ by at least one observer; all other images were considered ‘adequate’ for all areas. In the Ca-AEC orientation, at least a 44% dose reduction was achievable (p < 0.001) when only the outer AEC chambers were used. In the Cr-AEC orientation, at least 11% dose reduction was achieved (p < 0.001); here the central chamber was used alone, or in combination. IQ scores fell, but remained ‘adequate’. Conclusion: Switching pelvic orientation relative to AEC chamber position can optimise radiation dose during pelvic radiography. AEC chamber position should be clearly marked on equipment to facilitate this. AEC selection should be an active process.

Skin entrance dose with and without lead apron in digital panoramic radiography for selected sensitive body regions.

Science.gov (United States)

Schulze, Ralf Kurt Willy; Cremers, Catrin; Karle, Heiko; de Las Heras Gala, Hugo

2017-05-01

The aim of this study was to compare the dose at skin level at five significant anatomical regions for panoramic radiography devices with and without lead apron by means of a highly sensitive dosimeter. A female RANDO-phantom was exposed in five different digital panoramic radiography systems, and the dose at skin level was assessed tenfold for each measurement region by means of a highly sensitive solid-state-dosimeter. The five measurement regions selected were the thyroid, both female breasts, the gonads, and a central region in the back of the phantom. For each panoramic machine, the measurements were performed in two modes: with and without a commercial lead apron specifically designed for panoramic radiography. Reproducibility of the measurements was expressed by absolute differences and the coefficient of variation. Values between shielded and unshielded doses were pooled for each region and compared by means of the paired Wilcoxon tests (p ≤ 0.05). Reproducibility as represented by the mean CV was 22 ± 52 % (median 2.3 %) with larger variations for small dose values. Doses at skin level ranged between 0.00 μGy at the gonads and 85.39 μGy at the unshielded thyroid (mean ± SD 15 ± 24 μGy). Except for the gonads, the dose in all the other regions was significantly lower (p < 0.001) when a lead apron was applied. Unshielded doses were between 1.02-fold (thyroid) and 112-fold (at the right breast) higher than those with lead apron shielding (mean: 14-fold ± 18-fold). Although the doses were entirely very low, we observed a significant increase in dose in the radiation-sensitive female breast region when no lead apron was used. Future discussions on shielding requirements for panoramic radiography should focus on these differences in the light of the linear non-threshold (LNT) theory which is generally adopted in medical imaging.

Facial exposure dose assessment during intraoral radiography by radiological technologists

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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.

Measurements and applications of dose indices in radiography

International Nuclear Information System (INIS)

Chen, T.R.; Tyan, Y.S.; Yang, J.J.; Shao, C.H.; Lin, J.Y.; Tung, C.J.

2011-01-01

Assessments of radiation dose and image quality are required in diagnostic radiography for quality assurance and optimization studies. In work currently being undertaken, dose indices were measured and image quality evaluated for a chest PA procedure. Thermoluminescent dosimeters of the GR-200 type were attached to the entrance and exit surfaces and placed at various depths of the PMMA phantom to measure the entrance surface dose, the exit surface dose, and the organ dose index. The effective dose was estimated from the entrance surface dose using PCXMC software. Two contrast-detail image plates, one with air holes for the low contrast objects and the other with gypsum holes for the high contrast objects, were used to obtain radiographic images. This image plate was placed at different depths from the entrance surface of the phantom to simulate objects at different positions in the body. Each image was evaluated by three independent radiologists to determine image quality. Analyses of radiation dose versus image quality were performed to determine the optimal technical factors such as, filtration and tube potential. It was found that an 11-cm thick PMMA phantom best simulated the patients. The fractional dose backscattered from this phantom was between 22% and 27% for kVp’s between 66 and 133. Optimization analyses showed that no extra filter was required. For low contrast objects, an optimal choice of tube potential was 120 kVp. For high contrast objects, a kVp as low as 77 kVp could be used, depending on the image quality requirement.

Quality-controlled dose reduction of full-leg radiography in patients with knee malalignment

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Kloth, Jost Karsten; Neumann, Regina; Stiller, Wolfram; Kauczor, Hans-Ulrich; Weber, Marc-Andre [University Hospital Heidelberg, Department of Diagnostic and Interventional Radiology, Heidelberg (Germany); Stillfried, Eva von; Ewerbeck, Volker [University Hospital Heidelberg, Department of Orthopedic and Trauma Surgery, Heidelberg (Germany)

2014-12-05

Digital plain radiographs of the full leg are frequently performed examinations of children and young adults. Thus, the objective of this work was to reduce the radiation exposure dependent on specific indications, and to determine objective quality-control criteria to ensure accurate assessment. Institutional review board approval and informed consent of all participants were obtained. In this prospective, randomized controlled, blinded, two-armed single-center study, 288 evaluable patients underwent plain radiography of the full leg with standard and reduced doses. The evaluation of the plain radiographs was conducted using the following criteria: mechanical axis, leg length, and maturation of the epiphyseal plate. Two blinded radiologists evaluated these criteria using a score ranging from 1 (definitely assessable) to 4 (not assessable). If a single criterion had been evaluated with a score of 3 or more points or all criteria with 2 points, the radiograph was scored as ''not assessable''. The study was designed as a non-inferiority trial. Eleven (3.8 %) examined X-rays were scored as not assessable. The rate of non-assessable radiographs with 33 % reduced dose was significantly not inferior to the rate of non-assessable radiographs with standard dose. The evaluation of the quality criteria was dose independent. Full-leg plain radiography in patients with knee malalignment can be performed at 33 % reduced dose without loss of relevant diagnostic information. (orig.)

Study of the equivalent dose distribution in organs and tissues using periapical odontological radiography

International Nuclear Information System (INIS)

Santos, H.F.S.; Cipeli, J.F.; Fortes, M.A.B.; Federico, C.A.

2017-01-01

In this article presents a study of the doses obtained in periapical odontological radiography in main tissues of the head, using thermoluminescent dosemeters of type TLD-700H applied to a anthropomorphic simulator. The results indicate that the skin and salivary glands received the highest doses and the risk of calculated injury was 1.44 x 10 -6 Sv -1 per radiograph

Dose and perceived image quality in chest radiography

International Nuclear Information System (INIS)

Veldkamp, Wouter J.H.; Kroft, Lucia J.M.; Geleijns, Jacob

2009-01-01

Chest radiography is the most commonly performed diagnostic X-ray examination. The radiation dose to the patient for this examination is relatively low but because of its frequent use, the contribution to the collective dose is considerable. Consequently, optimization of dose and image quality offers a challenging area of research. In this article studies on dose reduction, different detector technologies, optimization of image acquisition and new technical developments in image acquisition and post processing will be reviewed. Studies indicate that dose reduction in PA chest images to at least 50% of commonly applied dose levels does not affect diagnosis in the lung fields; however, dose reduction in the mediastinum, upper abdomen and retrocardiac areas appears to directly deteriorate diagnosis. In addition to patient dose, also the design of the various digital detectors seems to have an effect on image quality. With respect to image acquisition, studies showed that using a lower tube voltage improves visibility of anatomical structures and lesions in digital chest radiographs but also increases the disturbing appearance of ribs. New techniques that are currently being evaluated are dual energy, tomosynthesis, temporal subtraction and rib suppression. These technologies may improve diagnostic chest X-ray further. They may for example reduce the negative influence of over projection of ribs, referred to as anatomic noise. In chest X-ray this type of noise may be the dominating factor in the detection of nodules. In conclusion, optimization and new developments will enlarge the value of chest X-ray as a mainstay in the diagnosis of chest diseases.

Evaluation of the anode heel effect on the testes dose during pelvic radiography

Directory of Open Access Journals (Sweden)

Vahid Karami

2017-05-01

Full Text Available Background: Anode heel effect refers to reduction of radiation intensity in the anode side of X-ray tube. This variation in radiation intensity across the anode-cathode of X-ray tube can be benefited for decrease radiation exposure in some radiological examinations. The aim of this study was to evaluate the effect of anode heel orientation on the radiation dose received by the testes in male patients undergoing pelvic radiography. Methods: This is a cross-sectional study, conducted at one of the teaching hospitals of Ahvaz, Jundishapur University of Medical Science Ahvaz, Iran, from September 2015 to March 2016. In order to measure the profile of radiation intensity variation, 13 paired sets of high radiosensitive cylindrical lithium fluoride thermo-luminescent dosimeters (TLD aligned on the cathode-anode central axis upon the table and then irradiated using routine exposure parameters. The anode of X-ray tube was positioned toward the feet for 40 patients and toward the head for 39 patients undergoing pelvic radiography. For measure the entrance skin dose (ESD, 8 TLD chips were located on the central point of the radiation field and 5 TLDs were located on the testes position to measure the dose received. Results: Radiation intensity profile showed that radiation intensity decrease from the cathode to the anode side. Discrepancy of radiation intensity on central axis of cathode-anode was calculated about 35%. The radiation dose received by the testes was 26.74% lower for patients the anode directed toward the feet, compared to the patients in which the anode directed toward the head (FTC: 1.260±0.296 mGy, FTA: 0.923±0.167 mGy, P<0.05. There was no meaningful difference for the measured ESD of pelvis between two groups of patients (FTC: 1.256±0.315 mGy, FTA: 1.195±0.205 mGy, P=0.788. Conclusion: In pelvic radiography, positioning of testes directed to the anode of X-ray tube can decrease the receive dose.

Chest X-Ray (Chest Radiography)

Science.gov (United States)

... Resources Professions Site Index A-Z X-ray (Radiography) - Chest Chest x-ray uses a very small dose ... Radiography? What is a Chest X-ray (Chest Radiography)? The chest x-ray is the most commonly performed diagnostic ...

SU-D-209-06: Study On the Dose Conversion Coefficients in Pediatric Radiography with the Development of Children Voxel Phantoms

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Liu, Q [Institute of Radiation Medicine Fudan University, Shanghai (China); Shanghai General Hospital, Shanghai, Shanghai (China); Zhuo, W; Liu, H [Institute of Radiation Medicine Fudan University, Shanghai (China); Liu, Y; Chen, T [Shanghai General Hospital, Shanghai, Shanghai (China)

2016-06-15

Purpose: Conversion coefficients of organ dose normalized to entrance skin dose (ESD) are widely used to evaluate the organ doses directly using ESD without time-consuming dose measurement, this work aims to investigate the dose conversion coefficients in pediatric chest and abdomen radiography with the development of 5 years and 10 years old children voxel phantoms. Methods: After segmentation of organs and tissues from CT slice images of ATOM tissue-equivalent phantoms, a 5-year-old and a 10-year-old children computational voxel phantoms were developed for Monte Carlo simulation. The organ doses and the entrance skin dose for pediatric chest postero-anterior projection and abdominal antero-posterior projection were simulated at the same time, and then the organ dose conversion coefficients were calculated.To verify the simulated results, dose measurement was carried out with ATOM tissue-equivalent phantoms for 5 year chest radiography. Results: Simulated results and experimental results matched very well with each other, the result differences of all the organs covered in radiation field were below 16% for 5-year-old child in chest projection. I showed that the conversion coefficients of organs covered in the radiation field were much larger than organs out of the field for all the study cases, for example, the conversion coefficients of stomach, liver intestines, and pancreas are larger for abdomen radiography while conversion coefficients of lungs are larger for chest radiography. Conclusion: The voxel children phantoms were helpful to evaluate the radiation doses more accurately and efficiently. Radiation field was the essential factor that affects the organ dose, use reasonably small field should be encouraged for radiation protection. This work was supported by the National Natural Science Foundation of China(11475047)

SU-D-209-06: Study On the Dose Conversion Coefficients in Pediatric Radiography with the Development of Children Voxel Phantoms

International Nuclear Information System (INIS)

Liu, Q; Zhuo, W; Liu, H; Liu, Y; Chen, T

2016-01-01

Purpose: Conversion coefficients of organ dose normalized to entrance skin dose (ESD) are widely used to evaluate the organ doses directly using ESD without time-consuming dose measurement, this work aims to investigate the dose conversion coefficients in pediatric chest and abdomen radiography with the development of 5 years and 10 years old children voxel phantoms. Methods: After segmentation of organs and tissues from CT slice images of ATOM tissue-equivalent phantoms, a 5-year-old and a 10-year-old children computational voxel phantoms were developed for Monte Carlo simulation. The organ doses and the entrance skin dose for pediatric chest postero-anterior projection and abdominal antero-posterior projection were simulated at the same time, and then the organ dose conversion coefficients were calculated.To verify the simulated results, dose measurement was carried out with ATOM tissue-equivalent phantoms for 5 year chest radiography. Results: Simulated results and experimental results matched very well with each other, the result differences of all the organs covered in radiation field were below 16% for 5-year-old child in chest projection. I showed that the conversion coefficients of organs covered in the radiation field were much larger than organs out of the field for all the study cases, for example, the conversion coefficients of stomach, liver intestines, and pancreas are larger for abdomen radiography while conversion coefficients of lungs are larger for chest radiography. Conclusion: The voxel children phantoms were helpful to evaluate the radiation doses more accurately and efficiently. Radiation field was the essential factor that affects the organ dose, use reasonably small field should be encouraged for radiation protection. This work was supported by the National Natural Science Foundation of China(11475047)

Investigation on radiation doses to patients in digital radiography

International Nuclear Information System (INIS)

Qiu Zhengshuai; Deng Daping; Li Quantai; Song Gang; Su Xu

2014-01-01

Objective: To investigate the patients' radiation dose received in digital radiography(DR) and provide basic data for developing diagnostic reference levels. Methods: The patient's ESD was estimated using the TLDs and DAP was measured by the dose-area product meter. The E values were then calculated by the DAP using Monte Carlo data and RefDose software. Measurements were made for twelve types of examination: skull PA, skull LAT, chest PA, chest LAT, abdomen AP, pelvis AP, cervix spine PA, cervix spine LAT, thoracic spine PA, thoracic spine LAT, lumber spine PA and lumber spine LAT. Results: Both kV and mAs varied in the same type of examination for ESD, DAP and E(F = 33.47, 24.68, 43.19, P < 0.05). The dose each time for lumber spine LAT was the highest, reached 4.62 mGy in ESD and 2.26 Gy·cm 2 in DAP, respectively. The E of abdomen AP averaged as 0.59 mSv, higher than that of lumber spine LAT. Even for the same type of examination, the dose from each equipment was different. Conclusions: DR has the potential to reduce the patients' radiation doses. The guidance levels suitable for Chinese population should be established as soon as possible. (authors)

Digital radiography of the skeleton using a large-area detector based on amorphous silicon technology: Image quality and potential for dose reduction in comparison with screen-film radiography

International Nuclear Information System (INIS)

Volk, M.; Strotzer, M.; Holzkneckt, N.; Manke, C.; Lenhart, M.; Gmeinwieser, J.; Link, J.; Reiser, M.; Feuerback, S.

2000-01-01

AIM: The purpose of this study was to evaluate a large-area, flat-panel X-ray detector (FD), based on caesium-iodide (CsI) and amorphous silicon (a-Si) with respect to skeletal radiography. Conventional images were compared with digital radiographs using identical and reduced radiation doses. MATERIALS AND METHODS: Thirty consecutive patients were studied prospectively using conventional screen-film radiography (SFR; detector dose 2.5 μGy). Digital images were taken from the same patients with detector doses of 2.5, 1.25 and 0.625 μGy, respectively. The active-matrix detector had a panel size of 43 x 43 cm, a matrix of 3 x 3K, and a pixel size of 143 μm. All hard copies were presented in a random order to eight independent observers, who rated image quality according to subjective quality criteria. Results were assessed for significance using the Student's t -test (confidence level 95%). RESULTS: A statistically significant preference for digital over conventional images was revealed for all quality criteria, except for over-exposure (detector dose 2.5 μGy). Digital images with a 50% dose showed a small, statistically not significant, inferiority compared with SFR. The FD-technique was significantly inferior to SFR at 75% dose reduction regarding bone cortex and trabecula, contrast and overall impression. No statistically significant differences were found with regard to over- and under-exposure and soft tissue presentation. CONCLUSION: Amorphous silicon-based digital radiography yields good image quality. The potential for dose reduction depends on the clinical query. Volk, M. (2000)

Digital chest radiography: an update on modern technology, dose containment and control of image quality

International Nuclear Information System (INIS)

Schaefer-Prokop, Cornelia; Venema, Henk W.; Neitzel, Ulrich; Uffmann, Martin; Prokop, Mathias

2008-01-01

The introduction of digital radiography not only has revolutionized communication between radiologists and clinicians, but also has improved image quality and allowed for further reduction of patient exposure. However, digital radiography also poses risks, such as unnoticed increases in patient dose and suboptimum image processing that may lead to suppression of diagnostic information. Advanced processing techniques, such as temporal subtraction, dual-energy subtraction and computer-aided detection (CAD) will play an increasing role in the future and are all targeted to decrease the influence of distracting anatomic background structures and to ease the detection of focal and subtle lesions. This review summarizes the most recent technical developments with regard to new detector techniques, options for dose reduction and optimized image processing. It explains the meaning of the exposure indicator or the dose reference level as tools for the radiologist to control the dose. It also provides an overview over the multitude of studies conducted in recent years to evaluate the options of these new developments to realize the principle of ALARA. The focus of the review is hereby on adult applications, the relationship between dose and image quality and the differences between the various detector systems. (orig.)

Computed radiography in paediatrics

International Nuclear Information System (INIS)

Kelly, C.

1996-01-01

Computed radiography has also been called storage phosphor technology, digital luminescence radiography and scintillation phosphor technology, since it relies on phosphor imaging plate as an alternative to screen-film. One of the major advantages in the use of computed radiography (CR) is the consistent image quality independence of the radiographer and exposure used. And secondly a marked reduction in the need for repeat films was achieved and thus a decrease in dose to the patient. In some cases, dose was able to be reduced further due to the fact that the plates respond to lower doses and still provide adequate image quality. Digitalising the Cr image allows it to be transmitted to an imaging console. The images can then be stored on optical disc. 7 refs

A Study on the Exposure Parameter and the Patient Dose for Digital Radiography System in Daegoo

International Nuclear Information System (INIS)

Jo, Gwang Ho; Kang, Yeopng Han; Kim, Bu Sun

2008-01-01

Digital imaging for general radiography has many advantages over the film/screen systems, including a wider dynamic range and the ability to manipulate the images produced. The wider range means that acceptable images may by acquired at a range of dose levels, and therefore repeat exposures can be reduced. Digital imaging can result in the over use of radiation, however, because there is a tendency can be reduced. Digital imaging can result in the over use of radiation, however, because there is a tendency for images to be acquired at too high a dose. We investigated the actual exposure dose conditions on general radiography and a questionnaire survey was conducted with radiotechnologiest at medical institutions using digital radiology system. As a results, the dose of exposure was not controlled with patient's figure and dose optimization but was controlled by worker's convenience and image quality. Radio-technologiests often set up the exposure dose regardless of patient figure and body part to be examined. Many organizations, such as the International Commission on Radiological Protection, recommend to keep the dose as low as possible. In addition, they strongly recommend to keep the optimal but minimal dosage by proper training programs and constant quality control, including frequent patient dose evaluations and education.

Routine oblique radiography of the pediatric lumbar spine: is it necessary. [Oblique radiography entails more than double the gonadal radiation dose of frontal-lateral projections

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Roberts, F.F.; Kishore, P.R.S.; Cunningham, M.E.

1978-08-01

A series of 86 pediatric lumbar spine abnormalities was evaluated to determine the diagnostic benefit of radiography in oblique projection as compared to frontal-lateral projections alone. In only four patients was an abnormality apparent on the oblique view which had not already been demonstrated by the frontal-lateral series; each of these represented an isolated spondylolysis. Because the diagnostic yield was low at a patient cost of more than double the gonadal radiation dose, it is recommended that oblique views be eliminated in the routine radiography of the pediatric lumbar spine.

Digital chest radiography

DEFF Research Database (Denmark)

Debess, Jeanne Elisabeth; Johnsen, Karen Kirstine; Thomsen, Henrik

on collimation and dose reduction in digital chest radiography Methods and Materials A retrospective study of digital chest radiography is performed to evaluate the primary x-ray tube collimation of the PA and lateral radiographs. Data from one hundred fifty self-reliant female patients between 15 and 55 years...

Dose estimation in the crystalline lens of industrial radiography personnel using Monte Carlo Method

International Nuclear Information System (INIS)

Lima, Alexandre Roza de

2014-01-01

The International Commission on Radiological Protection, ICRP, in its publication 103, reviewed recent epidemiological evidence and indicated that, for the eye lens, the absorbed dose threshold for induction of late detriment is around 0.5 Gy. On this basis, on April 21, 2011, the ICRP recommended changes to the occupational dose limit in planned exposure situations, reducing the eye lens equivalent dose limit from 150 mSv to 20 mSv per year, on average, during the period of 5 years, with exposure not to exceed 50 mSv in a single year. This paper presents the dose estimation to eye lens, H p (10), effective dose and doses to important organs in the body, received by industrial gamma radiography workers, during planned or accidental exposure situations. The computer program Visual Monte Carlo was used and two relevant scenarios were postulated. The first is a planned exposure situation scenario where the operator is directly exposed to radiation during the operation. 12 radiographic exposures per day for 250 days per year, which leads to an exposure of 36,000 seconds or 10 hours per year were considered. The simulation was carried out using the following parameters: a 192 Ir source with 1.0 TBq of activity, the source/operator distance varying from 5 m to 10 m at three different heights of 0.2 m, 1.0 m and 2.0 m. The eyes lens doses were estimated as being between 16.9 mSv/year and 66.9 mSv/year and for H p (10) the doses were between 17.7 mSv/year and 74.2 mSv/year. For the accidental exposure situation scenario, the same radionuclide and activity were used, but in this case the doses were calculated with and without a collimator. The heights above ground considered were 1.0 m, 1.5 m e 2.0 m, the source/operator distance was 40 cm and, the exposure time 74 seconds. The eyes lens doses, for 1.5 m, were 12.3 mGy and 0.28 mGy without and with a collimator, respectively. Three conclusions resulted from this work. The first was that the estimated doses show that the new

The study on the image quality and patient exposure dose of chest radiography in Korea

International Nuclear Information System (INIS)

Lee, Sun Sook; Huh, Joon

1995-01-01

Recently, general radiography became to variety because of the continuous development of Inverter type generator and ortho chromatic system. Therefore, we must re-evaluate about patient exposure dose and image quality. I studied about chest radiography which has frequency among general radiography being used during FEB. to AUG., 1994 over 151 medical facilities from medical facilities that are located in Seoul area. The result obtained were as follows; 1) The rectification method of the generator were employing mainly single phase full wave in 82.8 %, three phase full wave in 11.26 % and Inverter type in 4.64 % and condenser type is 1.32 %. 2) Exposure kV was used below 80 kV in most medical facilities and 21.8 % of the medical facilities was using high tube voltage higher than 120 kV. 3) The exposure time was used below the 0.05 sec in 28.4 %, in 29.8 % of the medical facilities used above 0.1 sec. 4) The usage frequency of the added filter is 15.3 %, and among them compound filter was used only 4 %. 5) Rare earth screen was used in 37.7 %. 6) The average skin entrance dose was 0.25 mSv, the range of dose is 0.05∼0.79 mSv in each medical facilities. 7) The average density of the lung field is 1.76, 0.49 in lung side, 0.30 in mediastinum and 0.37 in heart shadow. Therefore it is required to improve all of these for increasing image quality and reducing patient exposure dose as soon as possible

Transmission dose estimation algorithm for in vivo dosimetry

International Nuclear Information System (INIS)

Yun, Hyong Geun; Shin, Kyo Chul; Huh, Soon Nyung; Woo, Hong Gyun; Ha, Sung Whan; Lee, Hyoung Koo

2002-01-01

Measurement of transmission dose is useful for in vivo dosimetry of QA purpose. The objective of this study is to develope an algorithm for estimation of tumor dose using measured transmission dose for open radiation field. Transmission dose was measured with various field size (FS), phantom thickness (Tp), and phantom chamber distance (PCD) with an acrylic phantom for 6 MV and 10 MV X-ray. Source to chamber distance (SCD) was set to 150 cm. Measurement was conducted with a 0.6 cc Farmer type ion chamber. Using measured data and regression analysis, an algorithm was developed for estimation of expected reading of transmission dose. Accuracy of the algorithm was tested with flat solid phantom with various settings. The algorithm consisted of quadratic function of log(A/P) (where A/P is area-perimeter ratio) and tertiary function of PCD. The algorithm could estimate dose with very high accuracy for open square field, with errors within ±0.5%. For elongated radiation field, the errors were limited to ±1.0%. The developed algorithm can accurately estimate the transmission dose in open radiation fields with various treatment settings

Transmission dose estimation algorithm for in vivo dosimetry

Energy Technology Data Exchange (ETDEWEB)

Yun, Hyong Geun; Shin, Kyo Chul [Dankook Univ., Seoul (Korea, Republic of); Huh, Soon Nyung; Woo, Hong Gyun; Ha, Sung Whan [Seoul National Univ., Seoul (Korea, Republic of); Lee, Hyoung Koo [Catholic Univ., Seoul (Korea, Republic of)

2002-07-01

Measurement of transmission dose is useful for in vivo dosimetry of QA purpose. The objective of this study is to develope an algorithm for estimation of tumor dose using measured transmission dose for open radiation field. Transmission dose was measured with various field size (FS), phantom thickness (Tp), and phantom chamber distance (PCD) with an acrylic phantom for 6 MV and 10 MV X-ray. Source to chamber distance (SCD) was set to 150 cm. Measurement was conducted with a 0.6 cc Farmer type ion chamber. Using measured data and regression analysis, an algorithm was developed for estimation of expected reading of transmission dose. Accuracy of the algorithm was tested with flat solid phantom with various settings. The algorithm consisted of quadratic function of log(A/P) (where A/P is area-perimeter ratio) and tertiary function of PCD. The algorithm could estimate dose with very high accuracy for open square field, with errors within {+-}0.5%. For elongated radiation field, the errors were limited to {+-}1.0%. The developed algorithm can accurately estimate the transmission dose in open radiation fields with various treatment settings.

The effect of dose reduction on image quality in digital radiography using a flat-panel detector: experimental study in rabbits

International Nuclear Information System (INIS)

Jung, Sung Il; Goo, Jin Mo; Lee, Hyun Ju; Moon, Woo Kyung; Lim, Kun Young; Cho, Gyung Goo; Kim, Ji Hoon; Im, Jung Gi; Choi, Jang Yong; Nam, Sang Hee

2005-01-01

To evaluate the effect of dose reduction on image quality in digital radiography using a flat-panel detector. Digital radiographs of 30 rabbits were obtained at two different dose levels (33.23 μGY for the standard dose group and 20.09 μGY for the reduced dose group). The amorphous selenium-based flat-panel detector system had a panel size of 7 x 8.5 inches, a matrix of 1280 x 1536 (pixels?), and a pixel pitch of 138 μm. Four observers evaluated the soft-copy images on a high-resolution video monitor (2560 x 2048 x 8 bits) in random order. The observers rated the visibility of 13 different anatomic structures on a 5-point scale, viz, the retrocardiac lung, subdiaphragmatic lung, heart border, diaphragmatic border, proximal airway, unobscured lung, liver border, kidney border, bowel gas, flank stripe, ribs, and vertebrae in the mediastinal and abdominal regions. Statistical significance was determined using Wilcoxon's signed rank test. There was no statistically significant difference in the visibility of the anatomic structures on digital radiography between the standard and reduced dose groups. Digital radiography using an amorphous selenium-based flat-panel detector can preserve the image quality, though the dose is reduced to 40% of the standard level

The effect of dose reduction on image quality in digital radiography using a flat-panel detector: experimental study in rabbits

Energy Technology Data Exchange (ETDEWEB)

Jung, Sung Il; Goo, Jin Mo; Lee, Hyun Ju; Moon, Woo Kyung; Lim, Kun Young; Cho, Gyung Goo; Kim, Ji Hoon; Im, Jung Gi [Seoul National College of Medicine, Seoul (Korea, Republic of); Choi, Jang Yong; Nam, Sang Hee [Inje University, Seoul (Korea, Republic of)

2005-07-15

To evaluate the effect of dose reduction on image quality in digital radiography using a flat-panel detector. Digital radiographs of 30 rabbits were obtained at two different dose levels (33.23 {mu}GY for the standard dose group and 20.09 {mu}GY for the reduced dose group). The amorphous selenium-based flat-panel detector system had a panel size of 7 x 8.5 inches, a matrix of 1280 x 1536 (pixels?), and a pixel pitch of 138 {mu}m. Four observers evaluated the soft-copy images on a high-resolution video monitor (2560 x 2048 x 8 bits) in random order. The observers rated the visibility of 13 different anatomic structures on a 5-point scale, viz, the retrocardiac lung, subdiaphragmatic lung, heart border, diaphragmatic border, proximal airway, unobscured lung, liver border, kidney border, bowel gas, flank stripe, ribs, and vertebrae in the mediastinal and abdominal regions. Statistical significance was determined using Wilcoxon's signed rank test. There was no statistically significant difference in the visibility of the anatomic structures on digital radiography between the standard and reduced dose groups. Digital radiography using an amorphous selenium-based flat-panel detector can preserve the image quality, though the dose is reduced to 40% of the standard level.

Estimation of dose to patients undergoing computed radiography x-ray examinations in some Khartoum hospitals

International Nuclear Information System (INIS)

Badri, Fatima Abulgasiem Abdulrhman

2015-12-01

This study was designed to evaluate the entrance surface air kerma to the patient during x-ray examination to (chest PA, lumbar spine AP and Lat, pelvis AP) by using computed radiography (CR) in different three hospitals in Khartoum. Three x-ray machines were covered. A total of 135 patients were evaluated. The entrance surface air kerma was calculated for each patient from the exposure parameters using cal dose software version 3.5. The obtained results showed that, the entrance surface air kerma range founded to be (0.28-1.59) for chest PA, (1.98-2.62) for lumbar spine and (0.438-2.47) for pelvis AP. The higher entrance surface air kerma for all projections were observed in Center 1, except for pelvis it is higher in center 2. And the lower entrance surface air kerma were observed in center 3. This study recommends that CR operator must to be used to achieve optimize the patient dose by use the best strategies available for reducing radiation dose, computed radiography must be used with high level of training for medical staff to reduce the dose, each radiology department should implement a patient dose measurement quality assurance programme, doses to the patients should be regularly monitored and the proposed national DRLs should be taken as guidance for optimization.(Author)

The level of knowledge and radiation safety practice amongst cardiovascular technology, medical assistant, nursing and diagnostic radiography students and dose monitoring in radiography laboratory of Kolej Islam Sains dan Teknologi, Kelantan

International Nuclear Information System (INIS)

Ainul Fadhlin Othman; Amran Abdul Majid

2013-01-01

Full-text: This study investigated the knowledge level and practices regarding radiation safety among the cardiovascular technology, medical assistant nursing and radiography diagnostic students of Kolej Islam Sains dan Teknologi (KIST). The objectives of this study are to monitor the dose rate at radiography lab and to propose the guideline on radiation safety topics to improve the syllabus. 274 respondents including 30 psychology students acting as the control group were asked to answer questions from the questionnaires which cover the topics of basic knowledge of radiation and radiation safety practice. There was a significant difference (p < 0.05) between the correct answers and courses for 18 questions except for the question 4. There was a significant different (p < 0.05) between the correct answers and year of study for the questions 4, 5, 7, 12 to 15 and 18 to 20. There was a significance different (p < 0.05) between the correct answers and gender for questions 7, 11 and 19. For area dose monitoring in the radiography diagnostic lab, the assessment report on film batches of 4 walls in the lab were recorded and Victoreen451-RYR survey meter was used to monitor the dose rate for 7 selected areas with the exposure factors set for the chest, abdomen, upper extremity, lower extremity and skull radiography examinations. The dose rates at area 1 to 4, area 5 during the examination of chest, abdomen and skull, area 6 during the examination of abdomen and area 7 during the examination of abdomen, had exceeded the dose limit for radiation worker. The dose rate at the area 1 and 4 are slightly higher than the other areas. The contributing factors are the distance, tube potential, collimation and X-ray tube angulation. This study had shown that the cardiovascular technology and diagnostic radiography students have better knowledge and radiation safety practice level than the medical assistant and nursing students. In general, the level of knowledge and radiation safety

First experience with digital radiography

International Nuclear Information System (INIS)

Buchmann, F.

1987-01-01

The digital radiogram is explained, its advantages being the various possibilities of image processing, loss-free transmission, recording and storage capabilities, and in special cases, prompt availability of processed images. Digital subtraction angiography (DSA) and the high-resolution method of digital, luminescent radiography, which replaced the conventional film-foil radiography, are explained as the first developments for the introduction of digital radiography, which today already is an applicable technique. (orig./MG) [de

Digital radiography of the chest

International Nuclear Information System (INIS)

Sakurai, Kenji; Hachiya, Junichi; Korenaga, Tateo; Nitatori, Toshiaki; Miyasaka, Yasuo; Furuya, Yoshiro

1984-01-01

Initial clinical experience in digital chest radiography utilizing photostimulable phosphor and scanning laser stimulated luminescence was reported. Image quality of conventional film/screen radiography and digital radiography was compared in 30 normal cases. Reflecting wide dynamic range of the system, improved image quality was confirmed in all 30 cases, particularly in visibility of various mediastinal structures and pulmonary vessels. High sensor sensitivity of the system enabled digital radiography to reduce radiation dose requirement significantly. Diagnostically acceptable chest images were obtained with approximately 1/5 of routine dose for conventional radiography without significant image quality degradation. Some artifact created by digital processing were mostly overcome by a routine use of simultaneous display of two different types of image processing and therefore was not an actual drawback from diagnostic standpoint. Further technical advancement of the system to be seen for digital storage, retrieval and tranceference of images. (author)

Central axis dose verification in patients treated with total body irradiation of photons using a Computed Radiography system

International Nuclear Information System (INIS)

Rubio Rivero, A.; Caballero Pinelo, R.; Gonzalez Perez, Y.

2015-01-01

To propose and evaluate a method for the central axis dose verification in patients treated with total body irradiation (TBI) of photons using images obtained through a Computed Radiography (CR) system. It was used the Computed Radiography (Fuji) portal imaging cassette readings and correlate with measured of absorbed dose in water using 10 x 10 irradiation fields with ionization chamber in the 60 Co equipment. The analytical and graphic expression is obtained through software 'Origin8', the TBI patient portal verification images were processed using software ImageJ, to obtain the patient dose. To validate the results, the absorbed dose in RW3 models was measured with ionization chamber with different thickness, simulating TBI real conditions. Finally it was performed a retrospective study over the last 4 years obtaining the patients absorbed dose based on the reading in the image and comparing with the planned dose. The analytical equation obtained permits estimate the absorbed dose using image pixel value and the dose measured with ionization chamber and correlated with patient clinical records. Those results are compared with reported evidence obtaining a difference less than 02%, the 3 methods were compared and the results are within 10%. (Author)

Digital radiography of scoliosis with a scanning method: radiation dose optimization

Energy Technology Data Exchange (ETDEWEB)

Geijer, Haakan; Andersson, Torbjoern [Department of Radiology, Oerebro University Hospital, 701 85 Oerebro (Sweden); Verdonck, Bert [Philips Medical Systems, P.O. Box 10,000, 5680 Best (Netherlands); Beckman, Karl-Wilhelm; Persliden, Jan [Department of Medical Physics, Oerebro University Hospital, 701 85 Oerebro (Sweden)

2003-03-01

The aim of this study was optimization of the radiation dose-image quality relationship for a digital scanning method of scoliosis radiography. The examination is performed as a digital multi-image translation scan that is reconstructed to a single image in a workstation. Entrance dose was recorded with thermoluminescent dosimeters placed dorsally on an Alderson phantom. At the same time, kerma area product (KAP) values were recorded. A Monte Carlo calculation of effective dose was also made. Image quality was evaluated with a contrast-detail phantom and Visual Grading. The radiation dose was reduced by lowering the image intensifier entrance dose request, adjusting pulse frequency and scan speed, and by raising tube voltage. The calculated effective dose was reduced from 0.15 to 0.05 mSv with reduction of KAP from 1.07 to 0.25 Gy cm{sup 2} and entrance dose from 0.90 to 0.21 mGy. The image quality was reduced with the Image Quality Figure going from 52 to 62 and a corresponding reduction in image quality as assessed with Visual Grading. The optimization resulted in a dose reduction to 31% of the original effective dose with an acceptable reduction in image quality considering the intended use of the images for angle measurements. (orig.)

Proton nuclear scattering radiography

International Nuclear Information System (INIS)

Duchazeaubeneix, J.C.; Faivre, J.C.; Garreta, D.

1982-10-01

Nuclear scattering of protons allows to radiograph objects with specific properties: direct 3- dimensional radiography, different information as compared to X-ray technique, hydrogen radiography. Furthermore, it is a well adapted method to gating techniques allowing the radiography of fast periodic moving systems. Results obtained on different objects (light and heavy materials) are shown and discussed. The dose delivery is compatible with clinical use, but at the moment, the irradiation time is too long between 1 and 4 hours. Perspectives to make the radiography faster and to get a practical method are discussed

Need for New Optimisation Strategies in CR and Direct Digital Radiography

International Nuclear Information System (INIS)

Busch, H.P.

2000-01-01

Digital imaging techniques such as Digital Image Intensifier Radiography and Digital Storage Phosphor (Selenium) Radiography are replacing conventional film-screen radiography more and more. The aim of this development is the extension of diagnostic capabilities and the reduction of side effects such as radiation dose. Conventional film-screen radiography and digital radiography are very different ways of imaging. For digital radiography specific post-processing is the link between imaging conditions and film documentation. Optimisation of the images includes new possibilities of post-processing and a broad range for variation of the dose. Especially in fluoroscopy, dose can be reduced significantly by new technical features like pulsed fluoroscopy. For digital radiography the European guidelines on quality criteria have to be applied to projection radiography, digital subtraction radiography and to fluoroscopy. Further work should lead to a definition of reference values for the dose and the image quality. This has to be done first for single exposures and fluoroscopic mode and secondly for diagnostic and interventional procedures. (author)

SU-E-J-158: Experimental Investigation of Proton Radiography Based On Time-Resolved Dose Measurements

Energy Technology Data Exchange (ETDEWEB)

Testa, M; Paganetti, H; Lu, H-M [Massachusetts General Hospital ' Harvard Medical School, Boston, MA (United States); Doolan, P [University College London (United Kingdom); H, Bentefour E [IBA, Warrenville, IL (United States)

2014-06-01

Purpose: To use proton radiography for i) in-vivo range verification of the brain fields of medulloblastoma patients in order to reduce the exit dose to the cranial skin and thus the risk of permanent alopecia; ii) for performing patient specific optimization of the calibration from CT-Hounsfield units to proton relative stopping power in order to minimize uncertainties of proton rang Methods: We developed and tested a prototype proton radiography system based on a single-plane scintillation screen coupled with a fast CCD camera (1ms sampling rate, 0.29x0.29 mm{sup 2} pixel size, 30×30 cm{sup 2} field of view). The method is based on the principle that, for passively scattered beams, the radiological depth of any point in the plateau of a spread-out Bragg-Peak (SOBP) can be inferred from the time-pattern of the dose rate measurements. We performed detector characterization measurements using complex-shape homogeneous phantoms and an Alderson phanto Results: Detector characterization tests confirmed the robustness of the technique. The results of the phantom measurements are encouraging in terms of achievable accuracy of the water equivalent thickness. A technique to minimize the degradation of spatial resolution due to multiple Coulomb scattering is discussed. Our novel radiographic technique is rapid (100 ms) and simultaneous over the whole field. The dose required to produce one radiograph, with the current settings, is ∼3 cG Conclusion: The results obtained with this simple and innovative radiography method are promising and motivate further development of technique. The system requires only a single-plane 2D dosimeter and it uses the clinical beam for a fraction of second with low dose to the patient.

Comparison of patient specific dose metrics between chest radiography, tomosynthesis, and CT for adult patients of wide ranging body habitus

International Nuclear Information System (INIS)

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

2014-01-01

Purpose: Given the radiation concerns inherent to the x-ray modalities, accurately estimating the radiation doses that patients receive during different imaging modalities is crucial. This study estimated organ doses, effective doses, and risk indices for the three clinical chest x-ray imaging techniques (chest radiography, tomosynthesis, and CT) using 59 anatomically variable voxelized phantoms and Monte Carlo simulation methods. Methods: A total of 59 computational anthropomorphic male and female extended cardiac-torso (XCAT) adult phantoms were used in this study. Organ doses and effective doses were estimated for a clinical radiography system with the capability of conducting chest radiography and tomosynthesis (Definium 8000, VolumeRAD, GE Healthcare) and a clinical CT system (LightSpeed VCT, GE Healthcare). A Monte Carlo dose simulation program (PENELOPE, version 2006, Universitat de Barcelona, Spain) was used to mimic these two clinical systems. The Duke University (Durham, NC) technique charts were used to determine the clinical techniques for the radiographic modalities. An exponential relationship between CTDI vol and patient diameter was used to determine the absolute dose values for CT. The simulations of the two clinical systems compute organ and tissue doses, which were then used to calculate effective dose and risk index. The calculation of the two dose metrics used the tissue weighting factors from ICRP Publication 103 and BEIR VII report. Results: The average effective dose of the chest posteroanterior examination was found to be 0.04 mSv, which was 1.3% that of the chest CT examination. The average effective dose of the chest tomosynthesis examination was found to be about ten times that of the chest posteroanterior examination and about 12% that of the chest CT examination. With increasing patient average chest diameter, both the effective dose and risk index for CT increased considerably in an exponential fashion, while these two dose metrics

Comparison of patient specific dose metrics between chest radiography, tomosynthesis, and CT for adult patients of wide ranging body habitus

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yakun [Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Li, Xiang [Medical Physics Graduate Program, Department of Physics, Cleveland State University, Cleveland, Ohio 44115 (United States); Segars, W. Paul [Medical Physics Graduate Program, Carl E. Ravin Advanced Imaging Laboratories, and Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Samei, Ehsan, E-mail: samei@duke.edu [Medical Physics Graduate Program, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Departments of Physics, Biomedical Engineering, and Electrical and Computer Engineering, Duke University Medical Center, Durham, North Carolina 27705 (United States)

2014-02-15

Purpose: Given the radiation concerns inherent to the x-ray modalities, accurately estimating the radiation doses that patients receive during different imaging modalities is crucial. This study estimated organ doses, effective doses, and risk indices for the three clinical chest x-ray imaging techniques (chest radiography, tomosynthesis, and CT) using 59 anatomically variable voxelized phantoms and Monte Carlo simulation methods. Methods: A total of 59 computational anthropomorphic male and female extended cardiac-torso (XCAT) adult phantoms were used in this study. Organ doses and effective doses were estimated for a clinical radiography system with the capability of conducting chest radiography and tomosynthesis (Definium 8000, VolumeRAD, GE Healthcare) and a clinical CT system (LightSpeed VCT, GE Healthcare). A Monte Carlo dose simulation program (PENELOPE, version 2006, Universitat de Barcelona, Spain) was used to mimic these two clinical systems. The Duke University (Durham, NC) technique charts were used to determine the clinical techniques for the radiographic modalities. An exponential relationship between CTDI{sub vol} and patient diameter was used to determine the absolute dose values for CT. The simulations of the two clinical systems compute organ and tissue doses, which were then used to calculate effective dose and risk index. The calculation of the two dose metrics used the tissue weighting factors from ICRP Publication 103 and BEIR VII report. Results: The average effective dose of the chest posteroanterior examination was found to be 0.04 mSv, which was 1.3% that of the chest CT examination. The average effective dose of the chest tomosynthesis examination was found to be about ten times that of the chest posteroanterior examination and about 12% that of the chest CT examination. With increasing patient average chest diameter, both the effective dose and risk index for CT increased considerably in an exponential fashion, while these two dose

A study on reducing radiation dose in dental radiography for children, 2

International Nuclear Information System (INIS)

Shikone, Mitsuru; Tsuchida, Atsushi; Tateno, Hidemi; Uchimura, Noboru; Higaki, Morio; Kanno, Masanori; Higashi, Tomomitsu

1987-01-01

Although it is well understood that diagnostic dental radiographic examination is an indispensible procedure of the dental examination, it always carries the danger of radiation harm especially to the pedodontic patients who are more radiosensitive than the adult group. At the time of exposure, in specific, certain undeveloped tissues such as the thyroid (reverting postmitotic cells), the optic lens, and the reproductive cells (gonads) must be shielded from any unnecessary radiation. In this study, using the pedodontic intraoral radiographic examination method, four various cervical shields of four separate manufacturers were investigated. With the aid of the Thermo Luminescent Dosimeter (TLD), the specific exposure doses to the thyroid gland region were analyzed. At the same time, individual cervical shield's adaptation to the neck was examined. The results were as follows: (1) Even with the use of the cervical shield, maximum dose of 98.64 ± 11.13 mR (lower molar periapical radiography method), and minimum of 34.27 ± 6.69 mR (lower anterior periapical radiography method) were obtained at the thyroid gland region. (2) It was discovered that poor adaptation of the cervical shield to the neck and also poor adaptation of the long cones (position indicating devices, PID) occured upon patient opening his/her mouth. (author)

Reduction of radiation dose by using digital luminescence radiography compared to conventional screen film system with grid cassette

International Nuclear Information System (INIS)

Heyne, J.P.; Merbold, H.; Neumann, R.; Freesmeyer, M.; Jonetz-Mentzel, L.; Kaiser, W.A.; Sehner, J.

1999-01-01

Purpose: How much can the radiation dose be reduced for skull radiography by using digital luminescence radiography (DLR) compared to a conventional screen film system with a grid cassette? Methods and Materials: A skull phantom (3M) was X-rayed in anterior-posterior orientation using both a conventional screen film system with grid cassette and DLR (ADC-70, Agfa). The tube current time product (mAs) was diminished gradually while keeping the voltage constant. The surface entrance dose was measured by a sensor of Dosimax (Wellhoefer). Five investigators evaluated the images by characteristic and critical features, spatial resolution and contrast. Results: The surface entrance dose at 73 kV/22 mAs was 0,432 mGy in conventional screen film system and 0,435 mGy in DLR. The images could be evaluated very well down to an average dose of 71% (0,308 mGy; SD 0,050); sufficient images were obtained down to an average dose of 31% (0,136 mGy; SD 0,065). The resolution of the line pairs were reduced down to a 2 levels depending on the investigator. Contrast was assessed as being very good to sufficient. The acceptance of the postprocessed images (MUSICA-software) was individually different and resultde in an improvement of the assessment of bone structures an contrast in higher dose ranges only. Conclusion: For the sufficient assessment of a possible fracture/of paranasal sinuses/of measurement the skull the dose can be reduced to at least 56% (31%; SD 14,9%)/40% (27%; SD 9,3%)/18% (14%; SD 4,4%). Digital radiography allows question-referred exposure parameters with clearly reduced dose, so e.g. for fracture exclusion 73 kV/12,5 mAs and to skull measurement 73 kV/4 mAs. (orig.) [de

Reducing radiation doses to the breast, thyroid and gonads during diagnostic radiography

International Nuclear Information System (INIS)

Weatherburn, G.C.

1983-01-01

The skin entry and exit doses on patients undergoing routine radiographic examinations of areas in which the breast, thyroid and gonads are included in the primary beam were measured using thermoluminescent dosimeters. To obtain further information about patient doses, measurements were also made on a phantom at similar skin positions and at the positions of these organs. Comparisons of the doses to these radiosensitive organs were made for the antero-posterior and postero-anterior projections. In cases where it was found that the doses were reduced by the use of non-conventional relationship between the relative positions of the patient and the film, suggestions are made for the adaptations which would have to be made to X-ray equipment to enable these projections to be taken routinely. Other techniques, such as air gap techniques and thyroid shielding, whereby patient doses can be reduced during routine radiography are also examined. Finally the implications of these results for radiation protection of patients are considered. (author)

[Radiation exposure of children in pediatric radiology. Part 5: organ doses in chest radiography].

Science.gov (United States)

Seidenbusch, M C; Schneider, K

2009-05-01

Reconstruction of organ doses of selected organs and tissues from radiographic settings and exposure data collected during chest X-ray examinations of children of various age groups performed in Dr. von Hauner's Kinderspital (children's hospital of the University of Munich, DvHK) between 1976 and 2007. The dosimetric data of all X-ray examinations performed since 1976 at DvHK were stored electronically in a database. After 30 years of data collection, the database now includes 305 107 radiological examinations (radiographs and fluoroscopies), especially 119 150 chest radiographs of all age groups. Reconstruction of organ doses in 40 organs and tissues in X-ray examinations of the chest was performed based on the conversion factor concept. The radiation exposure of organs in projection radiography is determined by the exact site of the organs relative to the edges of the X-ray field and the beam direction of X-rays. Optimal collimation in chest radiography can reduce the exposure of organs located at the periphery of the X-ray field, e. g. thyroid gland, stomach and partially the liver, by a factor of 2 to 3, while organs located in the center of the X-ray-field, e. g. thymus, breasts, lungs, esophagus and red bone marrow, are not affected by exact collimation. The high frequency of the roentgen examination of the chest in early age groups increases the collective radiation burden to radiosensitive organs. Therefore, radiation protection of the patient during chest radiographies remains of great importance.

Algorithm for optimisation of paediatric chest radiography

International Nuclear Information System (INIS)

Kostova-Lefterova, D.

2016-01-01

The purpose of this work is to assess the current practice and patient doses in paediatric chest radiography in a large university hospital. The X-ray unit is used in the paediatric department for respiratory diseases. Another purpose was to recommend and apply optimized protocols to reduce patient dose while maintaining diagnostic image quality for the x-ray images. The practice of two different radiographers was studied. The results were compared with the existing practice in paediatric chest radiography and the opportunities for optimization were identified in order to reduce patient doses. A methodology was developed for optimization of the x-ray examinations by grouping children in age groups or according to other appropriate indication and creating an algorithm for proper selection of the exposure parameters for each group. The algorithm for the optimisation of paediatric chest radiography reduced patient doses (PKA, organ dose, effective dose) between 1.5 and 6 times for the different age groups, the average glandular dose up to 10 times and the dose for the lung between 2 and 5 times. The resulting X-ray images were of good diagnostic quality. The subjectivity in the choice of exposure parameters was reduced and standardization has been achieved in the work of the radiographers. The role of the radiologist, the medical physicist and radiographer in the process of optimization was shown. It was proven the effect of teamwork in reducing patient doses at keeping adequate image quality. Key words: Chest Radiography. Paediatric Radiography. Optimization. Radiation Exposure. Radiation Protection

Proton nuclear scattering radiography

International Nuclear Information System (INIS)

Saudinos, J.

1982-04-01

Nuclear scattering of protons allows to radiograph objects with specific properties: 3-dimensional radiography, different information as compared to X-ray technique, hydrogen radiography. Furthermore the nuclear scattering radiography (NSR) is a well adapted method to gating techniques allowing the radiography of fast periodic moving objects. Results obtained on phantoms, formalin fixed head and moving object are shown and discussed. The dose delivery is compatible with clinical use, but at the moment, the irradiation time is too long between 1 and 4 hours. Perspectives to make the radiograph faster and to get a practical method are discussed

Influence of lead apron shielding on absorbed doses from panoramic radiography.

Science.gov (United States)

Rottke, D; Grossekettler, L; Sawada, K; Poxleitner, P; Schulze, D

2013-01-01

This study investigated the absorbed doses in a full anthropomorphic body phantom from two different panoramic radiography devices, performing protocols with and without applying a lead apron. A RANDO(®) full body phantom (Alderson Research Laboratories Inc., Stamford, CT) was equipped with 110 thermoluminescent dosemeters at 55 different sites and set up in two different panoramic radiography devices [SCANORA(®) three-dimensional (3D) (SOREDEX, Tuusula, Finland) and ProMax(®) 3D (Planmeca, Helsinki, Finland)] and exposed. Two different protocols were performed in the two devices. The first protocol was performed without any lead shielding, whereas the phantom was equipped with a standard adult lead apron for the second protocol. A two-tailed paired samples t-test for the SCANORA 3D revealed that there is no difference between the protocol using lead apron shielding (m = 87.99, s = 102.98) and the protocol without shielding (m = 87.34, s = 107.49), t(54) = -0.313, p > 0.05. The same test for the ProMax 3D showed that there is also no difference between the protocol using shielding (m = 106.48, s = 117.38) and the protocol without shielding (m = 107.75, s = 114,36), t(54) = 0.938, p > 0.05. In conclusion, the results of this study showed no statistically significant differences between a panoramic radiography with or without the use of lead apron shielding.

Effective radiation dose from semicoronal CT of the sacroiliac joints in comparison with axial CT and conventional radiography

Energy Technology Data Exchange (ETDEWEB)

Jurik, Anne Grethe; Boecker Puhakka, Katriina [Department of Radiology R, Aarhus University Hospital, Aarhus Kommunehospital, Noerrebrogade 44, 8000 Aarhus C (Denmark); Hansen, Jolanta [Department of Medical Physics, Aarhus University Hospital, Aarhus Kommunehospital, Noerrebrogade 44, 8000 Aarhus C (Denmark)

2002-11-01

The aim of this study was to evaluate the radiation dose given by semicoronal CT of the sacroiliac joints (SIJs) in comparison with axial CT and conventional radiography. The total effective radiation doses given by serial contiguous semicoronal and axial CT, using 5-mm slices, 120 kV and 330 mAs, were determined by measurement of organ doses using an anthropomorphic Rando Alderson phantom paced with thermoluminescence dosimeters. The doses given by conventional antero-posterior (AP) and oblique projections of the SIJs were determined similarly. In a female the total effective dose by semicoronal CT was found to be more than six times lower than by axial CT and 2.5 times lower than the dose use to obtain a conventional AP radiograph, the values being 102, 678, and 255 {mu}Sv, respectively. The effective dose by semicoronal CT was only a little higher than the dose given to obtain two oblique radiographs. In a male with lead protection of the gonads the dose by semicoronal CT was four times lower than by axial CT, but higher than by conventional radiography. In conclusion, the effective dose by semicoronal CT of the SIJs is lower than by axial CT, and in females a semicoronal CT implies a lower effective radiation dose that used to obtain an AP radiograph. (orig.)

Computed Radiography Exposure Indices in Mammography | Koen ...

African Journals Online (AJOL)

Computed Radiography Exposure Indices in Mammography. L Koen, C Herbst, W Rae. Abstract. Background. Studies indicate that computed radiography (CR) can lead to increased radiation dose to patients. It is therefore important to relate the exposure indicators provided by CR manufacturers to the radiation dose ...

Relative dose efficiencies of antiscatter grids and air gaps in pediatric radiography

International Nuclear Information System (INIS)

McDaniel, D.L.; Cohen, G.; Wagner, L.K.; Robinson, L.H.

1984-01-01

The relative dose efficiencies (RDE) of various antiscatter grids and air gaps were determined for conditions simulating those found in pediatric radiography, using phantoms representing a newborn child, a 5-yr-old and a 10-yr-old child. Our data indicate than an air gap is best for the newborn, due to the low levels of scatter. The 8:1 fiber grid or 15.2-cm air gap without a grid can improve dose efficiency (DE) for the 5-yr-old child by 20%--25% relative to the 3.3-cm air gap and no-grid technique, while for the 10-yr-old child, DE can be improved by 40% with an 8:1 fiber grid

Fractures of the thoracic spine in patients with minor trauma: Comparison of diagnostic accuracy and dose of biplane radiography and MDCT

Energy Technology Data Exchange (ETDEWEB)

Karul, M., E-mail: m.karul@uke.de [Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg (Germany); Bannas, P.; Schoennagel, B.P.; Hoffmann, A.; Wedegaertner, U.; Adam, G.; Yamamura, J. [Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg (Germany)

2013-08-15

Objectives: To investigate the accuracy of biplane radiography in the detection of fractures of the thoracic spine in patients with minor trauma using multidetector computed tomography (MDCT) as the reference and to compare the dose of both techniques. Methods: 107 consecutive trauma patients with suspected fractures of the thoracic spine on physical examination were included. All had undergone biplane radiography first, followed by a MDCT scan between October 2008 and October 2012. A fourfold table was used for the classification of the screening test results. Both the Chi-square test (χ{sup 2}) and the mean dose-length product (DLP) were used to compare the diagnostic methods. Results: MDCT revealed 77 fractures in 65/107 patients (60.7%). Biplane radiography was true positive in 32/107 patients (29.9%), false positive in 19/107 patients (17.8%), true negative in 23/107 (21.5%) and false negative in 33/107 patients (30.8%), showing a sensitivity of 49.2%, a specificity of 54.7%, a positive predictive value (PPV) of 62.7%, a negative predictive value (NPV) of 41.1%, and an accuracy of 51.4%. The presence of a fracture on biplane radiography was highly statistical significant, if this was simultaneously proven by MDCT (χ{sup 2} = 7.6; p = 0.01). None of the fractures missed on biplane radiography was unstable. The mean DLP on biplane radiography was 14.5 mGy cm (range 1.9–97.8) and on MDCT 374.6 mGy cm (range 80.2–871). Conclusions: The sensitivity and the specificity of biplane radiography in the diagnosis of fractures of the thoracic spine in patients with minor trauma are low. Considering the wide availability of MDCT that is usually necessary for taking significant therapeutic steps, the indication for biplane radiography should be very restrictive.

Optimizing image quality and dose for digital radiography of distal pediatric extremities using the contrast-to-noise ratio

International Nuclear Information System (INIS)

Hess, R.; Neitzel, U.

2012-01-01

Purpose: To investigate the influence of X-ray tube voltage and filtration on image quality in terms of contrast-to-noise ratio (CNR) and dose for digital radiography of distal pediatric extremities and to determine conditions that give the best balance of CNR and patient dose. Materials and Methods: In a phantom study simulating the absorption properties of distal extremities, the CNR and the related patient dose were determined as a function of tube voltage in the range 40 - 66 kV, both with and without additional filtration of 0.1 mm Cu/1 mm Al. The measured CNR was used as an indicator of image quality, while the mean absorbed dose (MAD) - determined by a combination of measurement and simulation - was used as an indicator of the patient dose. Results: The most favorable relation of CNR and dose was found for the lowest tube voltage investigated (40 kV) without additional filtration. Compared to a situation with 50 kV or 60 kV, the mean absorbed dose could be lowered by 24 % and 50 %, respectively, while keeping the image quality (CNR) at the same level. Conclusion: For digital radiography of distal pediatric extremities, further CNR and dose optimization appears to be possible using lower tube voltages. Further clinical investigation of the suggested parameters is necessary. (orig.)

Spectroscopic neutron radiography for a cargo scanning system

Energy Technology Data Exchange (ETDEWEB)

Rahon, Jill [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 (United States); Danagoulian, Areg, E-mail: aregjan@mit.edu [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 (United States); MacDonald, Thomas D. [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 (United States); Hartwig, Zachary S. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 (United States); Lanza, Richard C. [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 (United States)

2016-06-01

Detection of cross-border smuggling of illicit materials and contraband is a challenge that requires rapid, low-dose, and efficient radiographic technology. The work we describe here is derived from a technique which uses monoenergetic gamma rays from low energy nuclear reactions, such as {sup 11}B(d,nγ){sup 12}C, to perform radiographic analysis of shipping containers. Transmission ratios of multiple monoenergetic gamma lines resulting from several gamma producing nuclear reactions can be employed to detect materials of high atomic number (Z), the details of which will be described in a separate paper. Inherent in this particular nuclear reaction is the production of fast neutrons which could enable neutron radiography and further characterization of the effective-Z of the cargo, especially within the range of lower Z. Previous research efforts focused on the use of total neutron counts in combination with X-ray radiography to characterize the hydrogenous content of the cargo. We present a technique of performing transmitted neutron spectral analysis to reconstruct the effective Z and potentially the density of the cargo. This is made possible by the large differences in the energy dependence of neutron scattering cross-sections between hydrogenous materials and those of higher Z. These dependencies result in harder transmission spectra for hydrogenous cargoes than those of non-hydrogenous cargoes. Such observed differences can then be used to classify the cargo based on its hydrogenous content. The studies presented in this paper demonstrate that such techniques are feasible and can provide a contribution to cargo security, especially when used in concert with gamma radiography.

Radiation exposure to the patient during X-ray fluoroscopy and radiography

International Nuclear Information System (INIS)

Dimov, A.; Vassileva, J.

2006-01-01

Full text: The aim of this study is to assess the patient doses received during conventional and digital X-ray radiography, conventional fluoroscopy of the lungs, and one of the highest dose X-ray procedures - contrast examination of the large intestine (Barium enema examination). The measured quantity is Kerma area product (KAP), registered with a clinical dosimeter DRK-1 (Doza, Russia). A total number of 89 patients are included in the study. The Organ doses and Effective doses were assessed using Monte Carlo calculation code (PCXMC 1.4 (Finland). The measurements took place at the following X-ray units: a CGR (Koch and Sterzel) with two working posts - for radiography and fluoroscopy, a Philips Telediagnost (for barium enema) and an Oldelft N800HF Digidelca (for digital radiography of the chest). The typical KAP per procedure at digital radiography, conventional X-ray radiography and fluoroscopy and Barium enema examination are: 17; 95; 928 and 3630 cGy.cm 2 respectively; the average effective doses are: 0.022; 0.053; 0.728 and 8.0 mSv respectively. Doses to the lungs at digital radiography, conventional radiography and fluoroscopy are: 0.066; 0.136 and 2.412 mSv respectively and the dose to the upper and lower large intestine are: 11.7 and 8.6 mSv respectively. Conclusion: The approach used is applicable for assessment of radiation exposure to the patient during X-ray radiography and fluoroscopy. It needs registration of KAP meter readings when this device is installed on the stationary X-ray units

Patient doses during intra-oral radiography in dental offices

International Nuclear Information System (INIS)

Sakaino, Rie; Harata, Yasuo; Okano, Tomohiro; Sato, Kenji; Yosue, Takashi; Nishikawa, Keiichi; Sano, Tsukasa; Kobayashi, Ikuo

2011-01-01

Measurement of patient entrance dose (PED) and dose area product (DAP) at various dental offices in the Tokyo bay area and comparison of PEDs with the existing diagnostic reference levels recommended in the United Kingdom (UK). The survey included 28 dental clinics categorized by the type of intra-oral radiography used. PED was measured by placing an optically stimulated luminescence dosimeter (OSLD) at the tip of the cone. Exposure parameters were those used for the adult mandibular molar region in the respective clinics. The OSLD readings were calibrated using an ionizing chamber manufactured according to standards of the Japan Quality Assurance Organization. The area (A), of the X-ray beam, was calculated by exposing an X-ray film placed at the tip of the cone and measuring the exposed area. Then the DAP was calculated as the product of PED times A. The PED estimated at various dental clinics differed by a factor of 120. The mean, minimum, maximum, median and third quartile values of PEDs were 4.99, 0.18, 21.7, 3.60 and 5.76 mGy, respectively. At 60-70 kV, PEDs observed in clinics using digital imaging systems were below 2.1 mGy which was lower than that of clinics using films that were E-speed or faster. It was also observed that PEDs were directly proportional to the tube current and exposure time. The mean, minimum, maximum, median and third quartile of DAPs were 13.0, 0.45, 61.4, 9.34 and 13.4 cGy cm 2 , respectively. The DAP values showed a linear correlation coefficient of 0.99 with PED values. Measurement of PED and DAP using OSLD and X-ray film can play a useful role in optimization of radiation protection for patients during intra-oral radiography. This method can be conveniently applied to set up diagnostic reference levels by carrying out mass surveys in Japan. (author)

Absorbed and effective dose from periapical radiography by portable intraoral x-ray machine

International Nuclear Information System (INIS)

Cho, Jeong Yeon; Han, Won Jeong; Kim, Eun Kyung

2007-01-01

The purpose of this study was to measure the absorbed dose and to calculate the effective dose for periapical radiography done by portable intraoral x-ray machines. 14 full mouth, upper posterior and lower posterior periapical radiographs were taken by wall-type 1 and portable type 3 intraoral x-ray machines. Thermoluminescent dosemeters were placed at 23 sites at the layers of the tissue-equivalent ART woman phantom for dosimetry. Average tissue absorbed dose and radiation weighted dose were calculated for each major anatomical site. Effective dose was calculated using 2005 ICRP tissue weighted factors. On 14 full mouth periapical radiographs, the effective dose for wall-type x-ray machine was 30 Sv; for portable x-ray machines were 30 Sv, 22 Sv, 36 Sv. On upper posterior radiograph, the effective dose for wall-type x-ray machine was 4 Sv; for portable x-ray machines doses were 4 Sv, 3 Sv, 5 Sv. On lower posterior radiograph, the effective dose for wall type x-ray machine was 5 Sv; for portable x-ray machines doses were 4 Sv, 4 Sv, 5 Sv. Effective doses for periapical radiographs performed by portable intraoral x-ray machines were similar to doses for periapical radiographs taken by wall type intraoral x-ray machines

Heavy-ion radiography

International Nuclear Information System (INIS)

Fabrikant, J.I.; Tobias, C.A.; Holley, W.R.; Benton, E.V.

1981-01-01

Heavy-particle radiography has clinical potential as a newly developed noninvasive low-dose imaging procedure that provides increased resolution of minute density differences in soft tissues of the body. The method utilizes accelerated high-energy ions, primarily carbon and neon, at the Bevalac accelerator at the Lawrence Berkeley Laboratory. The research program for medicine utilizes heavy-ion radiography for low-dose mammography, for treatment planning for cancer patients, and for imaging and accurate densitometry of skeletal structures, brain and spinal neoplasms, and the heart. The potential of heavy-ion imaging, and particularly reconstruction tomography, is now proving to be an adjunct to existing diagnostic imaging procedures in medicine, both for applications to the diagnosis, management and treatment of clinical cancer in man, and for the early detection of small soft-tissue tumors at low radiation dose

Bone X-Ray (Radiography)

Medline Plus

Full Text Available ... Radiography) - Bone Bone x-ray uses a very small dose of ionizing radiation to produce pictures of ... exposing a part of the body to a small dose of ionizing radiation to produce pictures of ...

Chest radiography: new technological developments and their applications

NARCIS (Netherlands)

Schalekamp, S.; Ginneken, B. van; Karssemeijer, N.; Schaefer-Prokop, C.M.

2014-01-01

Digital chest radiography is still the most common radiological examination. With the upcoming three-dimensional (3D) acquisition techniques the value of radiography seems to diminish. But because radiography is inexpensive, readily available, and requires very little dose, it is still being used

Modern digital plain-radiography of the whole spine in scoliosis patients. Dose reduction and quality criteria

International Nuclear Information System (INIS)

Kloth, Jost Karsten; Stiller, W.; Kauczor, H.U.; Weber, M.A.

2013-01-01

To reduce the radiation exposure of plain radiographs of the entire spine depending on specific indications, since these are frequently performed examinations of children and young adults with scoliosis and to determine objective quality control criteria to ensure accurate assessment. In this prospective randomized study 323 patients underwent plain-radiography of the entire spine with standard and 50 % reduced dose. In an experimental pilot-study this target-dose was determined using an Alderson-Phantom. The evaluation of the experimental radiographs, as well as, the randomized plain-radiographs was conducted using the following criteria: endplates (Cobb-angle), spinal process and pedicel (rotation), lateral margin of the vertebral body (lateral alignment), identification of C7 / S1 (perpendicular). Two radiologists evaluated these criteria using a score ranging from 1 (definitely assessable) to 4 (not assessable). If one single criteria was evaluated with a score of 3 or more points or more than 2 criteria with 2 points, the radiograph was scored as ''not assessable''. The statistical analysis was conducted as a non-inferiority-trial. Seven (2.4 %) of the 290 examined x-rays were scored as not assessable. There was no statistic inferiority between the examinations with standard or reduced dose, while singular assessment of the defined criteria was likewise dose-independent. Plain-radiography of the total spine in patients with scoliosis can be performed with a dose reduction of 50 % without a loss of validity. The obtained quality control criteria were clinically applicable. (orig.)

Phantom examination for reduction of radiation dose using new needle screen storage phosphor radiography and add beam filter in digital thoracic radiography on adolescents and larger children

International Nuclear Information System (INIS)

Heyne, J.P.; Mentzel, H.J.; Neumann, R.; Lopatta, E.; Zimmermann, U.; Kaiser, W.A.

2008-01-01

Purpose: how much can the radiation dose be reduced in thoracic radiography on adolescents and larger children by using needle screen storage phosphor (NIP) radiography and add beam filtration? Materials and methods: a chest phantom with typical anatomical structures, pathological findings, added catheters, and simulated nodules, tumors, and calcifications was X-rayed digitally (DX-S, Agfa Healthcare) in posterior-anterior (p.a.) orientation with and without add beam filter. While keeping the voltage constant, the tube current time product was reduced gradually. In addition to LgM, the surface entrance dose (ED) and the dose area product (DAP) were measured by the Dosimax sensor and Kerma X-plus (both Wellhoefer). Five investigators evaluated the images for characteristics and critical features, pathological findings, and catheter recognizability. Results: the ED of the digital chest radiogram p.a. with 115 kV and 0.71 mAs was 27 μGy, the DAP 3.6 μGy x m 2 , the LgM value 1.56. This initial radiogram was able to be evaluated very well and conforms to the quality guidelines. The dose-reduced chest radiograms with the add beam filter Al 1.0 mm/Cu 0.1 mm were evaluated as sufficiently reduced to a dose of 63% of the initial dose, with the add beam filter Al 1.0 mm/Cu 0.2 mm reduced to 50% (0.52 mAs, DAP 1.82 μGy x m 2 , LgM 1.35). P.a. radiograms were able to be X-rayed on 115 kV with 0.52 mAs. (orig.)

Radiography – How do students understand the concept of radiography?

International Nuclear Information System (INIS)

Lundgren, S.M.; Lundén, M.; Andersson, B.T.

2015-01-01

Background: Radiography as a concept has mainly been associated with the functional role of the radiographer. The concept has been studied from a theoretical point of view. However, there is a lack of a theoretical foundation and research on the actual substance of the term radiography used in education. It is therefore important to undertake an investigation in order to determine how students after three years education understand the subject of radiography. Aim: The aim of this study was to analyse how students in the Swedish radiographers' degree program understand the concept of radiography. Method: A concept analysis was made according to the hybrid model, which combines theoretical, fieldwork and analytical phases. A summative content analysis was used to identify the number and content of statements. The empirical data were collected from questionnaires answered by radiography students at four universities in Sweden. Findings: All radiography students' exemplified radiography with statements related to the practical level although some of them also identified radiography at an abstract level, as a subject within a discipline. The attribute ‘An interdisciplinary area of knowledge’ emerged, which is an attribute on the abstract level. The practical level was described by four attributes: Mastering Medical Imaging’, ‘To accomplish images for diagnosis and interventions’, ‘Creating a caring environment’ and ‘Enabling fruitful encounters’. Conclusion: The hybrid model used was a versatile model of concept development. The results of this study have increased the understanding of what characterizes the concept of radiography in a Swedish context. - Highlights: • This concept analysis of radiography was undertaken according to a hybrid model. • In radiography humanistic aspects are emphasized, a shift from the technological perspective. • The attributes demonstrate the essence and interdisciplinary nature of radiography. • This

Awareness of radiation protection and dose levels of imaging procedures among medical students, radiography students, and radiology residents at an academic hospital: Results of a comprehensive survey.

Science.gov (United States)

Faggioni, Lorenzo; Paolicchi, Fabio; Bastiani, Luca; Guido, Davide; Caramella, Davide

2017-01-01

To evaluate the awareness of radiation protection issues and the knowledge of dose levels of imaging procedures among medical students, radiology residents, and radiography students at an academic hospital. A total of 159 young doctors and students (including 60 radiology residents, 56 medical students, and 43 radiography students) were issued a questionnaire consisting of 16 multiple choice questions divided into three separated sections (i.e., demographic data, awareness about radiation protection issues, and knowledge about radiation dose levels of common radiological examinations). Medical students claimed to have at least a good knowledge of radiation protection issues more frequently than radiology residents and radiography students (94.4% vs 55% and 35.7%, respectively; Pradiological procedures was significantly worse among medical students than radiology residents and radiography students (Pradiology residents as to knowledge of radiation protection issues (PRadiology residents, radiography students and medical students have a limited awareness about radiation protection, with a specific gap of knowledge concerning real radiation doses of daily radiological examinations. Both undergraduate and postgraduate teaching needs to be effectively implemented with radiation safety courses. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Quality assurance in digital radiography

International Nuclear Information System (INIS)

Busch, H.P.; Lehmann, K.J.

1989-01-01

At present, there is no standard way of evaluating performance characteristics of digital radiography systems. Continuous measurements of performance parameters are necessary in order to obtain images of high quality. Parameters of quality assurance in digital radiography, which can be evaluated with simple, quick methods, are spatial resolution, low-contrast detectability, dynamic range and exposure dose. Spatial resolution was determined by a lead bar pattern, whereas the other parameters were measured by commercially available phantoms. Performance measurements of 10 digital subtraction angiography (DSA) units and one digital radiography system for unsubtracted digital radiography were assessed. From these results, recommendations for performance parameter levels will be discussed. (author)

Problems associated with digital luminescence radiography in the neonate and young infant. Problems with digital radiography.

Science.gov (United States)

Arthur, R J; Pease, J N

1992-01-01

An evaluation of the Siemens Digiscan has been undertaken to determine whether digital luminescence radiography (DLR) could replace conventional radiography in the examination of the neonate and young infant. Whilst the overall image quality of the digital radiograph was consistently higher than for conventional radiography the difference was less marked than we had expected. Furthermore, the potential for reduction in radiation dose by reducing the repeat rate due to incorrect exposure was limited. The potential advantages of DLR have been critically examined in relationship to neonatal radiography and a number of problems encountered during the evaluation have been highlighted.

Awareness of radiation protection and dose levels of imaging procedures among medical students, radiography students, and radiology residents at an academic hospital: Results of a comprehensive survey

International Nuclear Information System (INIS)

Faggioni, Lorenzo; Paolicchi, Fabio; Bastiani, Luca; Guido, Davide; Caramella, Davide

2017-01-01

Highlights: • Medical students tend to overstate their knowledge of radiation protection (RP). • Overall RP knowledge of young doctors and students is suboptimal. • RP teaching to undergraduates and postgraduates needs to be substantially improved. - Abstract: Purpose: To evaluate the awareness of radiation protection issues and the knowledge of dose levels of imaging procedures among medical students, radiology residents, and radiography students at an academic hospital. Material and methods: A total of 159 young doctors and students (including 60 radiology residents, 56 medical students, and 43 radiography students) were issued a questionnaire consisting of 16 multiple choice questions divided into three separated sections (i.e., demographic data, awareness about radiation protection issues, and knowledge about radiation dose levels of common radiological examinations). Results: Medical students claimed to have at least a good knowledge of radiation protection issues more frequently than radiology residents and radiography students (94.4% vs 55% and 35.7%, respectively; P < 0.05), with no cases of perceived excellent knowledge among radiography students. However, the actual knowledge of essential radiation protection topics such as regulations, patient and tissue susceptibility to radiation damage, professional radiation risk and dose optimisation, as well as of radiation doses delivered by common radiological procedures was significantly worse among medical students than radiology residents and radiography students (P < 0.05). Those latter significantly outperformed radiology residents as to knowledge of radiation protection issues (P < 0.01). Overall, less than 50% of survey respondents correctly answered all questions of the survey. Conclusions: Radiology residents, radiography students and medical students have a limited awareness about radiation protection, with a specific gap of knowledge concerning real radiation doses of daily radiological

Awareness of radiation protection and dose levels of imaging procedures among medical students, radiography students, and radiology residents at an academic hospital: Results of a comprehensive survey

Energy Technology Data Exchange (ETDEWEB)

Faggioni, Lorenzo, E-mail: lfaggioni@sirm.org [Department of Diagnostic and Interventional Radiology, University of Pisa, Via Roma 67, 56100, Pisa (Italy); Paolicchi, Fabio [Department of Diagnostic and Interventional Radiology, University of Pisa, Via Roma 67, 56100, Pisa (Italy); Bastiani, Luca [Institute of Clinical Physiology, National Research Council, Via Moruzzi 1, 56124, Pisa (Italy); Guido, Davide [Unit of Biostatistics and Clinical Epidemiology, Department of Public Health, Experimental and Forensic Medicine, University of Pavia, Via Forlanini 2, 27100, Pavia (Italy); Caramella, Davide [Department of Diagnostic and Interventional Radiology, University of Pisa, Via Roma 67, 56100, Pisa (Italy)

2017-01-15

Highlights: • Medical students tend to overstate their knowledge of radiation protection (RP). • Overall RP knowledge of young doctors and students is suboptimal. • RP teaching to undergraduates and postgraduates needs to be substantially improved. - Abstract: Purpose: To evaluate the awareness of radiation protection issues and the knowledge of dose levels of imaging procedures among medical students, radiology residents, and radiography students at an academic hospital. Material and methods: A total of 159 young doctors and students (including 60 radiology residents, 56 medical students, and 43 radiography students) were issued a questionnaire consisting of 16 multiple choice questions divided into three separated sections (i.e., demographic data, awareness about radiation protection issues, and knowledge about radiation dose levels of common radiological examinations). Results: Medical students claimed to have at least a good knowledge of radiation protection issues more frequently than radiology residents and radiography students (94.4% vs 55% and 35.7%, respectively; P < 0.05), with no cases of perceived excellent knowledge among radiography students. However, the actual knowledge of essential radiation protection topics such as regulations, patient and tissue susceptibility to radiation damage, professional radiation risk and dose optimisation, as well as of radiation doses delivered by common radiological procedures was significantly worse among medical students than radiology residents and radiography students (P < 0.05). Those latter significantly outperformed radiology residents as to knowledge of radiation protection issues (P < 0.01). Overall, less than 50% of survey respondents correctly answered all questions of the survey. Conclusions: Radiology residents, radiography students and medical students have a limited awareness about radiation protection, with a specific gap of knowledge concerning real radiation doses of daily radiological

New patient-controlled abdominal compression method in radiography: radiation dose and image quality.

Science.gov (United States)

Piippo-Huotari, Oili; Norrman, Eva; Anderzén-Carlsson, Agneta; Geijer, Håkan

2018-05-01

The radiation dose for patients can be reduced with many methods and one way is to use abdominal compression. In this study, the radiation dose and image quality for a new patient-controlled compression device were compared with conventional compression and compression in the prone position . To compare radiation dose and image quality of patient-controlled compression compared with conventional and prone compression in general radiography. An experimental design with quantitative approach. After obtaining the approval of the ethics committee, a consecutive sample of 48 patients was examined with the standard clinical urography protocol. The radiation doses were measured as dose-area product and analyzed with a paired t-test. The image quality was evaluated by visual grading analysis. Four radiologists evaluated each image individually by scoring nine criteria modified from the European quality criteria for diagnostic radiographic images. There was no significant difference in radiation dose or image quality between conventional and patient-controlled compression. Prone position resulted in both higher dose and inferior image quality. Patient-controlled compression gave similar dose levels as conventional compression and lower than prone compression. Image quality was similar with both patient-controlled and conventional compression and was judged to be better than in the prone position.

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

Science.gov (United States)

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

2014-02-01

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

Assessment of micro-dose biplanar radiography in lower limb measurements in children

International Nuclear Information System (INIS)

Lerisson, Heloise; Amzallag-Bellenger, Elisa; Cebulski-Delebarre, Aurelie; Boutry, Nathalie; Nectoux, Eric; Herbaux, Bernard; Desmulliez, Geoffrey; Duhamel, Alain; Drumez, Elodie

2018-01-01

To evaluate in children microdose protocol compared with low dose for lower limb alignment (LLA) measurements on biplanar radiography. Children 6 years or older were included. Height, weight and hip width were measured prior to imaging. Hip width allowed classifying children into morphotype M1 (width <25 cm), M2 (25-35 cm) or M3 (>35 cm) corresponding to predefined acquisition parameters (kV, mA, tube speed). Micro- and low-dose protocols were used alternately, with simultaneous acquisition of frontal and lateral radiographs. LLA measurements were performed by two independent observers (n = 526). In 15 children per morphotype, a third observer performed measurements twice (n = 180). Intraclass correlation coefficients and the dose (delivered, absorbed) were calculated. 100 girls and 160 boys (mean age = 11.7 years) were investigated: 74 M1 (mean BMI, 15.7kg/m 2 ), 149 M2 (19.8 kg/m 2 ) and 40 M3 (30.2 kg/m 2 ). With microdose, inter- and intra-observer agreement was >0.90 for lengths whatever the morphotype, 0.75-0.90 (M1) and >0.90 (M2, M3) for valgus/varus and flexion/hyperextension deviations. Dose reduction reached a factor of 8.5 and 5.4 for the delivered and absorbed dose respectively. Microdose could be used for LLA measurements in children and permits a significant dose reduction. (orig.)

SU-E-I-54: Effective Dose and Radiation Cancer Risks for Scoliosis Patients Undergoing Full Spine Radiography

Energy Technology Data Exchange (ETDEWEB)

Lin, Y [Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, 259, Wen-Hwa 1st Road., Kwei-Shan, Taoyuan 333, Taiwan (China); Hwang, Y [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan (China); Tsai, H [Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, 259, Wen-Hwa 1st Road., Kwei-Shan, Taoyuan 333, Taiwan (China); Medical Physics Research Center, Institute for Radiological Research, Chang Gung University / Chang Gung Memorial Hospital, Linkou, Taoyuan 33302, Taiwan (China); Healthy Aging Research Center, Chang Gung University, Taoyuan, Taiwan (China)

2015-06-15

Purpose: Scoliotic patients underwent a lot of radiologic examinations during the control and treatment periods. This study used the PCXMC program to calculate the effective dose of the patients and assess the radiation cancer risks. Methods: Seventy five scoliotic patients were examined using CR or DR systems during the control and treatment periods in Chang Gung Memorial Hospital. The technical factors were recorded for each patient during his/her control and treatment period. The entrance surface dose was measured using thermoluminence dosimeters and derived from technical factors and irradiated geometry. The effective dose of patients and relative radiation cancer risks were calculated by the PCXMC program. All required information regarding patient age and sex, the x-ray spectra, and the tube voltage and current were registered. The radiation risk were estimated using the model developed by the BEIR VII committee (2006). Results: The effective doses of full spine radiography with anteroposterior and lateral projections were 0.626 mSv for patients using DR systems, and 0.483mSv for patients using CR systems, respectively. The dose using DR system was 29.6% higher than those using CR system. The maximum organ dose was observed in the breast for both projections in all the systems. The risk of exposure—induced cancer death (REID) of patients for DR and CR systems were 0.009% and 0.007%, respectively. Conclusion: The risk estimates were regarded with healthy skepticism, placed more emphasis on the magnitude of the risk. The effective doses estimated in this study could be served as a reference for radiologists and technologists and demonstrate the necessity to optimize patient protection for full spine radiography though the effective doses are not at the level to induce deterministic effects and not significant in the stochastic effect. This study was supported by the grants from the Chang Gung Memorial Hospital (CMRPD1D0421)

A study on the evaluation of radiation doses in dental radiography

International Nuclear Information System (INIS)

Sugimoto, Koju

1980-01-01

Radiation doses and possible biological risks due to dental full mouth examination (adult: 10-film technique, child: 6-film technique) were evaluated based on preliminary experiments and statistical surveillance of patients' records. Dosimetrical studies were performed by using head and neck phantoms and a dental x-ray tube. Radiation doses were measured by x-ray films and thermoluminescence dosimeters. For the obtained doses of skin, eyes, thyroid gland and bone marrow, the biological risk of leukemia and thyroid cancer was discussed on the statistical basis of patients at Kanagawa Dental College Hospital. The major findings were as follows: The total number of patients who recieved full mouth x-ray examination at Kanagawa Dental College Hospital in 1978 was 1,099. The number of male patients was 382 (3,804 films) and that of female patients was 717 (7,138 films). In both sexes, the number of patients was the greatest in the group of 8 - 14 years of age. The collective doses of bone marrow due to full mouth 10-film examination performed at Kanagawa Dental College Hospital in 1978 were approximately 6.0 rad, which could induce leukemia with a probability of 1/8,000. The collective doses of thyroid gland were approximately 13 rad, which could induce lethal thyroid cancer with a probability of 1/15,000. The radiation dose due to the dental radiography for examination at Kanagawa Dental College Hospital was proved to be apparently below the level that could actually induce radiation injuries. But the collective radiation doses due to dental examination in Japan as a whole were approximately 8,000 times greater than that in Kanagawa Dental College Hospital. (J.P.N.)

Root cause analysis of the radiation workers (radiography) in excess doses of NBD (case study: PT. XYZ)

International Nuclear Information System (INIS)

Arifin M Wibowo; Fajariadi; Aditia Anamta

2013-01-01

Negligence and non-compliance is the main factor of causing an incident in radiography. It shown as the result of TLD evaluation of PT. XYZ workers exceeding the dose limit (NBD). Root cause analysis stage begin in collecting data such as license, workers permit, dose, and incident sequence report. Causal chart is a tool to identification root cause to make easier of the analysis. Results of collecting data are to be clarified in BAPETEN investigation and then there are some a recommendation to facility. (author)

Portable radiography using linear accelerators

International Nuclear Information System (INIS)

Reid, D.W.

1984-01-01

There are numerous instances where the availability of a portable high-energy radiography machine that could be transported to the inspection site with relative ease would save time, money, and make radiography of permanent installations, such as bridges, possible. One such machine, the Minac built by Schoenberg Radiation Inc., is commercially available. It operates at 9.3 GHz, has an electron energy on target of 3.5 MeV, and an output dose rate of 100 R/min. A second portable accelerator, recently completed at the Los Alamos National Laboratory, operates at 2.998 GHz, has electron energies on target of 6, 8, and 10 MeV, and an output dose rate of 800 R/min at 8 MeV. This paper discusses the need for and applications of portable accelerators for radiography. Physical characteristics and beam parameters of both machines are examined in detail. Problems of operating at higher frequencies to further minimize size and weight are discussed

Effects on patient exposure dose and image quality by increasing focal film distance in abdominal radiography

International Nuclear Information System (INIS)

Kim, You Hyun; Kwon, Soo Il

1998-01-01

We can and must improve the diagnostic images using available knowledge and technology. At the same time we must strive to reduce thr patient's integral and entrance radiation dose. Reducing the integral dose to the patient during the radiologic procedure is a primary concern of the patient, especially the pediatric patient, the radiologist and the technologist. A 100cm focal film distance generally is used for most over-table radiography. The early x-ray tubes and screen film combinations required long exposures, which often resulted in motion artifacts. But nowadays, we have the generators and x-ray tubes that can deliver the energy necessary in a very short time and the receptors that can record the information just as rapidly. And, we performed this studies to evaluate the patient exposure dose and the image quality by increasing focal film distance in diagnostic radiography. There are many factors which affected to exposure factor, but we studied to verify of FFD increase, only. Effect of increasing the focal film distance to a 140 cm distance was tested as follows ; 1. The focal film distances were set at 100, 120, and 140cm. 2. A 18cm acryl(tissue equivalent) phantom was placed on the table top. 3. An Capintec 192 electrometer with PM 05 ion chamber was placed at the entrance surface of the phantom, and exposure were made at each focal film distances. 4. The procedure was repeated in the same manner as above except the ion chamber was placed beneath the phantom at the film plane. 5. Exit exposure were normalize to 8mR for each portions of the experiment. Based on the success of the empirical measurements, a detailed mathematical analysis of the dose reduction was performed using the percent depth dose data

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

International Nuclear Information System (INIS)

Cho, Bong Hae; Nah, Kyung Soo; Lee, Ae Ryeon

1995-01-01

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 μSv and 20.93 μSv, those in child mode were 462 μSv and 11.54 μSv, respectively. 2. Total effective doses to the critical head and neck organs were estimated 34.2l μSv in adult mode, 20.14 μSv in child mode. From these data, the probabilities of stochastic effect from adult and child mode were 2.50xl0 -6 and 1.47x10 -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.

Digital chest radiography

DEFF Research Database (Denmark)

Debess, Jeanne Elisabeth; Vejle-Sørensen, Jens Kristian; Thomsen, Henrik

,3 mAs and SID SID of 180 centimetres using a phantom and lithium fluoride thermo luminescence dosimeter (TLD). Dose to risk organs mamma, thyroid and colon are measured at different collimations with one-centimetre steps. TLD results are used to estimate dose reduction for different collimations...... at the conference. Conclusion: Collimation improvement in basic chest radiography can reduce the radiation to female patients at chest x-ray examinations....

Industrial radiography in the Philippines: safety concerns

International Nuclear Information System (INIS)

David, Jocelyn L.; Artificio, Thelma P.; Cerbolles, Justina S.; Caseria, Estrella S.; Agron, Inocencio A.

2005-01-01

Industrial radiography utilizes the highest activity (5.55 tera becquerel (TBq) to 7.4 TBq) among the various mobile application of radioisotopes. It is highly possible that radiographers exceed the annual dose limits for workers occupationally exposed to radiation (as prescribed in the Code of PNRI Regulations part 3) if they do not give cautious consideration to the factors that determine the radiation dose, namely: the gamma source dose rates, time distance and shielding. To enhance the safety culture among radiographers, various strategies are recommended to be undertaken by the Philippine Nuclear Research Institute as well as the licensed companies undertaking activities in industrial radiography. (Authors)

Characterization and validation of the thorax phantom Lungman for dose assessment in chest radiography optimization studies.

Science.gov (United States)

Rodríguez Pérez, Sunay; Marshall, Nicholas William; Struelens, Lara; Bosmans, Hilde

2018-01-01

This work concerns the validation of the Kyoto-Kagaku thorax anthropomorphic phantom Lungman for use in chest radiography optimization. The equivalence in terms of polymethyl methacrylate (PMMA) was established for the lung and mediastinum regions of the phantom. Patient chest examination data acquired under automatic exposure control were collated over a 2-year period for a standard x-ray room. Parameters surveyed included exposure index, air kerma area product, and exposure time, which were compared with Lungman values. Finally, a voxel model was developed by segmenting computed tomography images of the phantom and implemented in PENELOPE/penEasy Monte Carlo code to compare phantom tissue-equivalent materials with materials from ICRP Publication 89 in terms of organ dose. PMMA equivalence varied depending on tube voltage, from 9.5 to 10.0 cm and from 13.5 to 13.7 cm, for the lungs and mediastinum regions, respectively. For the survey, close agreement was found between the phantom and the patients' median values (deviations lay between 8% and 14%). Differences in lung doses, an important organ for optimization in chest radiography, were below 13% when comparing the use of phantom tissue-equivalent materials versus ICRP materials. The study confirms the value of the Lungman for chest optimization studies.

Reconstructive dosimetry and radiation doses evaluation of members of the public due to radiological accident in industrial radiography

International Nuclear Information System (INIS)

Lima, Camila Moreira Araujo de

2016-01-01

Radiological accidents have occurred mainly in the practices recognized as high risk radiological and classified by the IAEA as Categories 1 and 2, and highlighted the radiotherapy, industrial irradiators and industrial radiography. In Brazil, since there were five major cases in industrial radiography, which involved 7 radiation workers and 19 members of the public, causing localized radiation lesions on the hands and fingers. One of these accidents will be the focus of this work. In this accident, a "1"9"2Ir radioactive source was exposed for more than 8 hours in the workplace inside a company, exposing radiation workers, individuals of the public and people from the surrounding facilities, including children of a school. The radioactive source was also handled by a security worker causing severe radiation injuries in the hand and fingers. In this paper, the most relevant and used techniques of reconstructive dosimetry internationally are presented. To estimate the radiation doses received by exposed individuals in various scenarios of radiological accident in focus, the following computer codes were used: Visual Monte Carlo Dose Calculation (VMC), Virtual Environment for Radiological and Nuclear Accidents Simulation (AVSAR) and RADPRO Calculator. Through these codes some radiation doses were estimated, such as, 33.90 Gy in security worker's finger, 4.47 mSv in children in the school and 55 to 160 mSv for workers in the company during the whole day work. It is intended that this work will contribute to the improvement of dose reconstruction methodology for radiological accidents, having then more realist radiation doses. (author)

Salivary gland doses from dental radiographic exposures

International Nuclear Information System (INIS)

Hoshi, Masaharu; Kato, Kazuo; Wada, Takuro; Antoku, Shigetoshi; Russell, W.J.

1989-01-01

Salivary gland doses incurred during dental radiography were measured by phantom dosimetry, and these dose data and data obtained during a two-week survey of Hiroshima and Nagasaki dental hospitals and clinics were used to estimate the respective doses to members of the populations of the two cities. The results obtained were used to supplement previously determined doses to the thyroid gland, lens, and pituitary gland from dental radiography. No significant differences in doses were observed by age, sex or city. Doses to the salivary glands during dental radiography are probably not sufficiently large to cause bias in assessments of atomic bomb survivors for late radiation effects. However, the steadily increasing use of dental radiography underscores the need for continued monitoring of dental radiography doses in the interests of these assessments. (author)

Is radiography justified for the evaluation of patients presenting with cervical spine trauma?

Energy Technology Data Exchange (ETDEWEB)

Theocharopoulos, Nicholas; Chatzakis, Georgios; Damilakis, John [Department of Medical Physics, Faculty of Medicine, University of Crete, P.O. Box 2208, Iraklion, 71003 Crete (Greece) and Department of Natural Sciences, Technological Education Institute of Crete, P.O. Box 140, Iraklion 71004 Crete (Greece); Department of Radiology, Faculty of Medicine, University of Crete, P.O. Box 2208, Iraklion, 71003 Crete (Greece); Department of Medical Physics, Faculty of Medicine, University of Crete, P.O. Box 2208, Iraklion, 71003 Crete (Greece)

2009-10-15

Conventional radiography has been for decades the standard method of evaluation for cervical spine trauma patients. However, currently available helical multidetector CT scanners allow multiplanar reconstruction of images, leading to increased diagnostic accuracy. The purpose of this study was to determine the relative benefit/risk ratio between cervical spine CT and cervical spine radiography and between cervical spine CT and cervical spine radiography, followed by CT as an adjunct for positive findings. A decision analysis model for the determination of the optimum imaging technique was developed. The sensitivity and specificity of CT and radiography were obtained by dedicated meta-analysis. Lifetime attributable risk of mortal cancer from CT and radiography was calculated using updated organ-specific risk coefficients and organ-absorbed doses. Patient organ doses from radiography were calculated using Monte Carlo techniques, simulated exposures performed on an anthropomorphic phantom, and thermoluminescence dosimetry. A prospective patient study was performed regarding helical CT scans of the cervical spine. Patient doses were calculated based on the dose-length-product values and Monte Carlo-based CT dosimetry software program. Three groups of patient risk for cervical spine fracture were incorporated in the decision model on the basis of hypothetical trauma mechanism and clinical findings. Radiation effects were assessed separately for males and females for four age groups (20, 40, 60, and 80 yr old). Effective dose from radiography amounts to 0.050 mSv and from a typical CT scan to 3.8 mSv. The use of CT in a hypothetical cohort of 10{sup 6} patients prevents approximately 130 incidents of paralysis in the low risk group (a priori fracture probability of 0.5%), 500 in the moderate risk group (a priori fracture probability of 2%), and 5100 in the high risk group (a priori fracture probability of 20%). The expense of this CT-based prevention is 15-32 additional

The advantages of digital radiography in department of radiology

International Nuclear Information System (INIS)

Mao Lijuan; Luo Xiaomei; Wu Tengfang

2009-01-01

Objective: To investigate the advantages of digital radiography in department of radiology by comparing digital radiography with common radiography. Methods: Test card was used for testing the spatial resolution of DR and common radiography. 1000 films of chest by DR and 1000 films of chest by common radiography were compared in image quality, dose of radiation, the rate of waste film, and the advantages of DR was analyzed. Results: Compared to common radiography, DR had a high sensitivity, high DQE (quantum detection efficiency), high spatial resolution and density resolution. The speed of acquisition and X-ray conversion efficiency were fast. The function of post-processing was strong and the rate of disease detection was high. Conclusion: DR is better than common radiography in all respects, it will be widely applied. (authors)

Management of pediatric radiation dose using Canon digital radiography

International Nuclear Information System (INIS)

Arreola, M.; Rill, L.

2004-01-01

A Canon CXDI-11 digital radiography (DR) system has been in use at Shands Hospital at the University of Florida for the past 2 1/2 years. A first clinical implementation phase was utilized to develop imaging protocols for adult patients, with a second phase incorporating pediatric chest and abdominal studies a few months later. This paper describes some of the steps taken during the modality implementation stages, as well as the methodologies and procedures utilized to monitor compliance by the technologists. The Canon DR system provides the technologist with an indication of the radiation exposure received by the detector (and thus of the patient dose) by means of an indirect exposure level number called the reached exposure (REX) value. The REX value is calculated by the system based on the default grayscale curve preselected for a given anatomical view and used by the system to optimize the appearance of the image. The brightness and contrast of the image can be modified by the user at the QC/control screen for the purpose of improving the appearance of the image. Such changes modify the actual grayscale curve (position and slope, respectively) and thus the calculated REX value. Thus, undisciplined use of the brightness and contrast functions by the technologist can render the REX value meaningless as an exposure indicator. The paper also shows how it is possible to calibrate AEC (phototimer) systems for use with the Canon DR system, and utilize the REX value as a valuable dose indicator through proper training of technologists and strict, disciplined QC of studies. A team consisting of the site's medical physicist, radiologists, and technologists, as well as Canon engineers, can work together in properly calibrating and setting up the system for the purposes of monitoring patient doses (especially pediatric) in DR studies performed in a Canon DR system. (orig.)

Dosimetric evaluation in panoramic and tele-radiography procedures

International Nuclear Information System (INIS)

Oliveira, Georgge Gomes

2004-01-01

The present work had as an objective to evaluate the skin surface entrance dose in panoramic and tele radiography procedures in three clinics in Recife - Pernambuco - Brazil, and to contribute with data for the determination of reference levels for super cited extra oral procedures, for this purpose, operational conditions in 3 clinics were evaluated in Recife, aiming to evaluate the existence and integrity of the radioprotection equipment, manner and conditions of image processing; and radiographic equipment parameters such as the dimension of the irradiation filed, the total filtration, the exposure time and the potential applied to the X ray tube. For an estimation of the skin entrance dose of the patient, the phantom Randon Alderson and thermoluminescence dosemeters were used. From these values and the conversion factors determined by the Monte Carlo technique, with the phantom MAX it was possible to estimate the dose absorbed in the organ due to the tele radiography procedures. Regarding panoramic radiography the study showed that the more elevated doses occurred in the parotid gland region which is near rotational venters. In the case of tele radiography the highest dose value occurred in the regions corresponding to the temporal lobe of the brain, followed by linfonodes, ears and parotid glands. The doses absorbed in the eyes and the thyroid gland were, 0.037 mGy and 0.002 mGy in Clinic A and 0.062 mGy and 0.003 mGy in Clinic C, respectively. Regarding equipment test, inadequacy was found in the beam collimation in Clinic A and in the reproducibility of the X ray exposure in Clinic C. The total filtration in both clinics was inadequate.(author)

Direct digital radiography versus storage phosphor radiography in the detection of wrist fractures

Energy Technology Data Exchange (ETDEWEB)

Peer, Siegfried; Neitzel, Ulrich; Giacomuzzi, Salvatore M.; Pechlaner, Sigurd; KUenzel, Karl Heinz; Peer, Regina; Gassner, Eva; Steingruber, Iris; Gaber, O.; Jaschke, Werner

2002-04-01

AIM: To define the value of digital radiography with a clinical flat panel detector system for evaluation of wrist fractures in comparison with state of the art storage phosphor radiography. MATERIAL AND METHODS: Hard copy images of 26 fractured wrist specimens were acquired with the same exposure dose on a state of the art storage phosphor radiography system and a clinical flat panel detector. Image features like cortical bone surface, trabecular bone, soft tissues and fracture delineation were independently analysed by 4 observers using a standardised protocol. Image quality ratings were evaluated with an analysis of variance (ANOVA). RESULTS: Flat panel detector radiographs were rated superior with respect to cortical and trabecular bone representation as well as fracture evaluation, while storage phosphor radiographs produced better soft tissue detail. CONCLUSION: In some of the observed image quality aspects, the performance of caesium iodide/amorphous silicon flat panel detector exceeds state of the art storage phosphor radiography. This makes it well suited for skeletal imaging particularly in trauma as seen in the detection of wrist fractures. Peer, S. et al. (2002)

Direct digital radiography versus storage phosphor radiography in the detection of wrist fractures

International Nuclear Information System (INIS)

Peer, Siegfried; Neitzel, Ulrich; Giacomuzzi, Salvatore M.; Pechlaner, Sigurd; KUenzel, Karl Heinz; Peer, Regina; Gassner, Eva; Steingruber, Iris; Gaber, O.; Jaschke, Werner

2002-01-01

AIM: To define the value of digital radiography with a clinical flat panel detector system for evaluation of wrist fractures in comparison with state of the art storage phosphor radiography. MATERIAL AND METHODS: Hard copy images of 26 fractured wrist specimens were acquired with the same exposure dose on a state of the art storage phosphor radiography system and a clinical flat panel detector. Image features like cortical bone surface, trabecular bone, soft tissues and fracture delineation were independently analysed by 4 observers using a standardised protocol. Image quality ratings were evaluated with an analysis of variance (ANOVA). RESULTS: Flat panel detector radiographs were rated superior with respect to cortical and trabecular bone representation as well as fracture evaluation, while storage phosphor radiographs produced better soft tissue detail. CONCLUSION: In some of the observed image quality aspects, the performance of caesium iodide/amorphous silicon flat panel detector exceeds state of the art storage phosphor radiography. This makes it well suited for skeletal imaging particularly in trauma as seen in the detection of wrist fractures. Peer, S. et al. (2002)

A radiological health study of industrial gamma radiography in Canada

International Nuclear Information System (INIS)

1979-05-01

As an occupational group, industrial radiographers receive radiation doses second only to reactor workers. This report is a result of a study carried out to research the causes for this relatively high dose and determine if and how it can be improved. The data presented herein were obtained from questionnaires and field visits to organizations involved in gamma radiography and from the Canadian National Dose Registry. Some applications of radiography such as pipeline work give rise to higher than average doses. When all safety measures are conscientiously aplied, the doses are reasonalbe. However, ignorance, carelessness and indifference account for much unnecessary exposure to radiation. (Auth)

Optimizing digital radiography of children

International Nuclear Information System (INIS)

Willis, Charles E.

2009-01-01

Pediatric projection imaging differs from imaging of the adult patient. Children are smaller, more radiosensitive, and less compliant than their adult counterparts. Their characteristics affect the way projection imaging is practiced and how dose is optimized. Computed radiography (CR) and digital radiography (DR) have been embraced by pediatric practitioners in order to reduce dose and improve image quality. Unfortunately, dose optimization with CR and DR has been hampered by a lack of definition of appropriate exposure levels, a lack of standardization in exposure factor feedback, and a lack of understanding of the fundamentals of CR and DR technology. The potential for over-exposure exists with both CR and DR. Both the Society for Pediatric Radiology and the American Association of Physicists in Medicine recognize the promise and shortcomings of CR and DR technology and have taken steps to join with manufacturers in improving the practice of CR and DR imaging. Although the risks inherent in pediatric projection imaging with CR and DR are low, efforts to reduce dose are worthwhile, so long as diagnostic quality is maintained. Long-standing recommendations for limiting radiation dose in pediatric projection imaging are still applicable to CR and DR.

Optimisation of radiation dose and image quality in mobile neonatal chest radiography.

Science.gov (United States)

Hinojos-Armendáriz, V I; Mejía-Rosales, S J; Franco-Cabrera, M C

2018-05-01

To optimise the radiation dose and image quality for chest radiography in the neonatal intensive care unit (NICU) by increasing the mean beam energy. Two techniques for the acquisition of NICU AP chest X-ray images were compared for image quality and radiation dose. 73 images were acquired using a standard technique (56 kV, 3.2 mAs and no additional filtration) and 90 images with a new technique (62 kV, 2 mAs and 2 mm Al filtration). The entrance surface air kerma (ESAK) was measured using a phantom and compared between the techniques and against established diagnostic reference levels (DRL). Images were evaluated using seven image quality criteria independently by three radiologists. Images quality and radiation dose were compared statistically between the standard and new techniques. The maximum ESAK for the new technique was 40.20 μGy, 43.7% of the ESAK of the standard technique. Statistical evaluation demonstrated no significant differences in image quality between the two acquisition techniques. Based on the techniques and acquisition factors investigated within this study, it is possible to lower the radiation dose without any significant effects on image quality by adding filtration (2 mm Al) and increasing the tube potential. Such steps are relatively simple to undertake and as such, other departments should consider testing and implementing this dose reduction strategy within clinical practice where appropriate. Copyright © 2017 The College of Radiographers. Published by Elsevier Ltd. All rights reserved.

Radiation doses in examination of lower third molars with computed tomography and conventional radiography.

Science.gov (United States)

Ohman, A; Kull, L; Andersson, J; Flygare, L

2008-12-01

To measure organ doses and calculate effective doses for pre-operative radiographic examination of lower third molars with CT and conventional radiography (CR). Measurements of organ doses were made on an anthropomorphic head phantom with lithium fluoride thermoluminescent dosemeters. The dosemeters were placed in regions corresponding to parotid and submandibular glands, mandibular bone, thyroid gland, skin, eye lenses and brain. The organ doses were used for the calculation of effective doses according to proposed International Commission on Radiological Protection 2005 guidelines. For the CT examination, a Siemens Somatom Plus 4 Volume Zoom was used and exposure factors were set to 120 kV and 100 mAs. For conventional radiographs, a Scanora unit was used and panoramic, posteroanterior, stereographic (scanogram) and conventional spiral tomographic views were exposed. The effective doses were 0.25 mSv, 0.060 mSv and 0.093 mSv for CT, CR without conventional tomography and CR with conventional spiral tomography, respectively. The effective dose is low when CT examination with exposure factors optimized for the examination of bone structures is performed. However, the dose is still about four times as high as for CR without tomography. CT should therefore not be a standard method for the examination of lower third molars. In cases where there is a close relationship between the tooth and the inferior alveolar nerve the advantages of true sectional imaging, such as CT, outweighs the higher effective dose and is recommended. Further reduction in the dose is feasible with further optimization of examination protocols and the development of newer techniques.

Diagnostic reference levels in intraoral dental radiography in Korea

International Nuclear Information System (INIS)

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

2012-01-01

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

Dose optimization in pelvic radiography by air gap method on CR and DR systems – A phantom study

International Nuclear Information System (INIS)

Chan, C.T.P.; Fung, K.K.L.

2015-01-01

Objectives: This study aimed at investigating the feasibility of replacing the anti-scatter grid with an air gap at a pelvic radiographic examination in order to reduce patient dose while retaining diagnostic image quality. Methods: An anthropomorphic pelvis phantom was placed on a device that allowed the adjustment of different air gap thicknesses introduced between the phantom and the image receptor of Computed Radiography (CR) and Digital Radiography (DR) systems. Grid and non-grid images with different air gap thicknesses of both systems were produced. Ovary and testes doses were measured using thermoluminescent dosimeters. Radiographic quality of all images was rated by 5 experienced radiographers blindly using the Image Quality Score (IQS) and Visual Grading Analysis (VGA) systems. Results: Images of diagnostic quality were produced while the grid was replaced by a range of 0–25 cm air gap thickness in the pelvic radiographic examination. At non-grid examination with 10 cm air gap thickness, a maximum of relative dose reduction by 70.7% and 81.6% at CR; 68.6% and 79.4% at DR were achieved respectively at ovary and testes locations of the phantom as compared with their corresponding grid examinations. Conclusion: 10 cm was found to be the optimal air gap thickness at the tested pelvic examination. Effective dose was found to be reduced by 2 and 2.3 times respectively at the CR and DR examinations while the anti-scatter grid was replaced by 10 cm air gap. However, dose reduction effect by air gap method was found to be more pronounced in CR than in DR. - Highlights: • 10 cm air gap was found to be a substitute to replace grid in pelvic RANDO in CR/DR. • Over 68.6% of dose reduction effect were achieved at the ovary and testes regions. • Over 76.4% of reduction in effective dose were achieved at both the tested regions. • Dose reduction by air gap method was found to be more pronounced in CR than in DR

Inspection of CF188 composite flight control surfaces with neutron radiography

International Nuclear Information System (INIS)

Lewis, W.J.; Bennett, L.G.I.; Mullin, S.K.

1996-01-01

At the Royal Military College of Canada's SLOWPOKE-2 Facility, a neutron radiography facility has been designed and installed using a small (20kWth), pool-type research reactor called the SLOWPOKE-2 (Safe Low Power c(K)ritical Experiment) as the neutron source. Since then, the research has continued along two fronts: developing applications and improving the quality of the neutron beam. The most interesting applications investigated to date has been the inspection of various metal ceramic composites and the inspection of the composite flight control surfaces of some of the CF188 Hornet aircraft. As part of the determination of the integrity of the aircraft, it was decided to inspect an aircraft with the highest flight house using both X- and neutron radiography. The neutron radiography and, to a lesser extent, X-radiography inspections completed at McClellan AFB revealed 93 anomalies. After returning to Canada, the component with the greatest structural significance, namely the right hand rudder from the vertical stabilizer, was removed from the aircraft and put through a rigorous program of numerous NDT inspections, including X-radiography (film and real-time), eddy current, ultrasonics (through transmission and pitch-catch), infrared thermography, and neutron radiography. Therefore, of all the techniques investigated, only through transmission ultrasonics and neutron radiography were able to identify large areas of hydration. However, only neutron radiography could identify the small areas of moisture and hydration. Given the structural significance of the flight control surfaces in modern fighter aircraft, even the smallest amounts of hydration could potentially lead to catastrophic results

An experimental comparative study of radiography, ultrasonography and CT imaging in the IV catheter fragment

International Nuclear Information System (INIS)

Kweon, Dae Cheol

2016-01-01

The objective of this study was to detect the fragments generated during IV (intravenous) catheter injection of contrast medium and drug administration in a clinical setting and removal was performed by experimentally producing a phantom, and to compare the radiography, ultrasonography, and multi-detector computed tomography (MDCT) imaging and radiation dose. A 1 cm fragment of an 18 gage Teflon® IV catheter with saline was inserted into the IV control line. Radiography, CT, and ultrasonography were performed and radiography and CT dose were calculated. CT and ultrasonography showed an IV catheter fragment clinically and radiography showed no visible difference in the ability to provide a useful image of an IV catheter fragment modality (p >.05). Radiography of effective dose (0.2139 mSv·Gy-1·cm-2) form DAP DAP (0.93 μGy·m2 ), and dose length product (DLP) (201 mGy·cm) to effective dose was calculated as 0.483 mSv. IV catheter fragment were detected of radiography, ultrasonography and CT. These results can be obtained by menas of an excellent IV catheter fragment of detection capability CT. However, CT is followed by radiation exposure. IV catheter fragment confirming the position and information recommend an ultrasonography

A model-based radiography restoration method based on simple scatter-degradation scheme for improving image visibility

Science.gov (United States)

Kim, K.; Kang, S.; Cho, H.; Kang, W.; Seo, C.; Park, C.; Lee, D.; Lim, H.; Lee, H.; Kim, G.; Park, S.; Park, J.; Kim, W.; Jeon, D.; Woo, T.; Oh, J.

2018-02-01

In conventional planar radiography, image visibility is often limited mainly due to the superimposition of the object structure under investigation and the artifacts caused by scattered x-rays and noise. Several methods, including computed tomography (CT) as a multiplanar imaging modality, air-gap and grid techniques for the reduction of scatters, phase-contrast imaging as another image-contrast modality, etc., have extensively been investigated in attempt to overcome these difficulties. However, those methods typically require higher x-ray doses or special equipment. In this work, as another approach, we propose a new model-based radiography restoration method based on simple scatter-degradation scheme where the intensity of scattered x-rays and the transmission function of a given object are estimated from a single x-ray image to restore the original degraded image. We implemented the proposed algorithm and performed an experiment to demonstrate its viability. Our results indicate that the degradation of image characteristics by scattered x-rays and noise was effectively recovered by using the proposed method, which improves the image visibility in radiography considerably.

Assessment of dose to patients undergoing computed radiography and film screen x-ray examinations in some Khartoum Hospitals

International Nuclear Information System (INIS)

Mohamed Khair, Haiffa Daffa Allah Mustafa

2015-12-01

Medical ionizing radiation sources give by far the largest contribution to the population dose from man made sources and most of the contribution comes from diagnostic x-rays. The optimization principle of radiation protection requires the minimization of radiation dose to patients while acquiring diagnostic quality images in radiology. In radiography, the extent of patient dose reduction is limited by the characteristics of the system used and the quality (or penetrating ability) of the x-ray beam. In this study, the entrance surface air kerma doses (ESA Ks) to patients undergoing 7 selected x-ray examinations were estimated. The study was conducted in eight hospitals in Khartoum State, comprising nine x-ray units and a total of 1200 patients were involved. Four of the hospitals involved in this study use computed radiography (CR) technology while the other four use film screen (FS) technology. The selected examinations were, abdomen (AP), chest (PA), pelvis (AP), skull (AP/PA), skull (LAT), thoracic spine (AP) and thoracic spine (LAT). The entrance surface air kerma was calculated by two methods, utilizing software CAL Dose X-3.5 and a mathematical model. Average ESAK values calculated using the two methods for hospitals using (CR) technology in mGy were 2.99 and 2.98, 0.34 and 0.31, 2.79 and 2.58, 0.76 and 0.71, 0.94 and 0.79, 3.4 and 3,2 and 5.9 and 5.03, for the above mentioned selected investigations respectively. And average ESAK values calculated using two methods for hospital using FS technology in mGy were found 4.98 and 4.19, 0.37 and 0.34, 4.15 and 3.95, 2.2 and 2. 1.3 and 1.1, 3.9 and 3.9, 9.4 and 8.3 for the above mentioned selected investigations respectively. Average ESAK values obtained by two methods for FS were higher values than the obtained by CR by 37 and 29%, 50 and 25%, 8%, 32 and 34%, 65 and 64%, 27 and 28%, 12% and 73% and 39% for the above mentioned selected investigations, respectively. This shows that CR technique allows diagnostically

Application of proton radiography to medical imaging

International Nuclear Information System (INIS)

Kramer, S.L.; Martin, R.L.; Moffett, D.R.; Colton, E.

1977-12-01

The use of charged particles for radiographic applications has been considered for some time, but progress has been impeded by the cost and availability of suitable accelerators. However, recent developments in technology could overcome these problems. A review is presented of the physical principles leading to an improvement in mass resolution per unit of absorbed dose for charged particle radiography relative to x-ray radiography. The quantitative comparisons between x-ray and proton radiographs presented here confirm this advantage. The implications of proton radiography on cancer detection, as well as future plans for developing a proton tomographic system, are discussed

Radiation protection in dental radiography

International Nuclear Information System (INIS)

Jozani, F.; Parnianpour, H.

1976-08-01

In considering the special provisions required in dental radiography, investigations were conducted in Iran. Radiation dose levels in dental radiography were found to be high. Patient exposure from intraoral radiographic examination was calculated, using 50kV X-ray. Thermoluminescent dosimeters were fastened to the nasion, eyes, lip, philtrum, thyroid, gonads and to the right and left of the supra-orbital, infra-orbital temporomandibular joints of live patients. The highest exposure value was for the lower lip. Recommendations concerning educational training and protection of staff and patients were included

Advantages of digital radiography: The DSI system

International Nuclear Information System (INIS)

Drouillard, J.

1990-01-01

The experience gained over a period of several months, applying the digital and image-enhanced radiography with the DSI system for examination of some hundreds of patients, has confirmed in our eyes the system's diagnostic and economic efficiency, and the important achievement of radiation dose abatement. Looking at the current results and improvements under way (Release 2), there is reason enough to support an extension of the range of indications, especially regarding arteriography and interventional radiography. According to our experience, the DSI system meets the requirements of a modern radiology department: reduction of operating costs, limitation of radiation dose, efficiency enhancement by digital imaging. (orig.) [de

Study on the evaluation of radiation doses in dental radiography. Doses and risks due to dental full mouth examination

Energy Technology Data Exchange (ETDEWEB)

Sugimoto, K [Kanagawa Dental Coll., Yokosuka (Japan)

1980-09-01

Radiation doses and possible biological risks due to dental full mouth examination (adult: 10-film technique, child: 6-film technique) were evaluated based on preliminary experiments and statistical surveillance of patients' records. Dosimetrical studies were performed by using head and neck phantoms and a dental x-ray tube. Radiation doses were measured by x-ray films and thermoluminescence dosimeters. For the obtained doses of skin, eyes, thyroid gland and bone marrow, the biological risk of leukemia and thyroid cancer was discussed on the statistical basis of patients at Kanagawa Dental College Hospital. The major findings were as follows: The total number of patients who recieved full mouth x-ray examination at Kanagawa Dental College Hospital in 1978 was 1,099. The number of male patients was 382 (3,804 films) and that of female patients was 717 (7,138 films). In both sexes, the number of patients was the greatest in the group of 8 - 14 years of age. The collective doses of bone marrow due to full mouth 10-film examination performed at Kanagawa Dental College Hospital in 1978 were approximately 6.0 rad, which could induce leukemia with a probability of 1/8,000. The collective doses of thyroid gland were approximately 13 rad, which could induce lethal thyroid cancer with a probability of 1/15,000. The radiation dose due to the dental radiography for examination at Kanagawa Dental College Hospital was proved to be apparently below the level that could actually induce radiation injuries. But the collective radiation doses due to dental examination in Japan as a whole were approximately 8,000 times greater than that in Kanagawa Dental College Hospital.

Glandular dose and image quality control in mammography facilities with computerized radiography systems

International Nuclear Information System (INIS)

Dantas, Marcelino Vicente de Almeida

2010-01-01

Breast cancer is the most common cancer among women, and early detection is critical to its diagnosis and treatment. To date, the most effective method for early detection of breast cancer has been x-ray mammography for which the screen/film (SF) technique has been the gold standard. However, even though SF combinations have been improved and optimized over the years for breast imaging, there are some critical limitations, including a narrow exposure range, image artifacts, film processing problems, and inflexibility in image processing and film management. In recent years, digital mammography has been introduced in cancer screening programmes with the screen/film techniques gradually being phased out. Computed radiography (CR), also commonly known as photostimulable phosphor (PSP) imaging or storage phosphor, employs reusable imaging plates and associated hardware and software to acquire and to display digital projection radiographs. In this work, a protocol model was tested for performing image quality control and average glandular dose (AGD) evaluation in 19 institutions with computed radiography systems for mammography. The protocol was validated through tests at the Laboratorio de Radioprotecao Aplicada a Mamografia (LARAM) from the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN). The image quality visual evaluation of CDMAM phantom showed that 53% of the facilities were able to produce images of excellent quality. Furthermore, the automated evaluation of image quality, using the analyze software cdcom.exe, showed that 57% of the images were considered to be of good quality. The detector linearity test showed that the CR response is very linear, where 95% of facilities evaluated were considered to be compliant. For the image noise was found that only 20% of facilities are in agreement with the parameters established for this test. The average glandular doses, which patients may be getting to perform an examination, were below the action levels

Evaluation of occupational exposure in intraoral radiography

International Nuclear Information System (INIS)

Miguel, Cristiano; Barros, Frieda S.; Rocha, Anna S.P.S.; Godoi, Walmor C.; Tilly Junior, Joao G.

2014-01-01

The intraoral radiography is widely performed in the dental office due to low cost and agility. The doses in intraoral radiology are considered low, however it is known that doses below the threshold for deterministic radiation has the potential to induce stochastic effects. An intraoral radiography has a risk of inducing fatal cancer or serious in order of 1:10,000,000. Besides the patient, the dentist may also be being exposed to radiation during the work with the radiographics practices. The bibliographies demonstrates the lack of information on radiation protection of dentists, however, the occupational dose reduction was observed in radiology over the past 14 years. This work aims to evaluate the effective dose of radiation to which workers can be exposed dentists in dental offices to perform intraoral radiographs. In this context, a study was be conducted between June 2013 and May 2014 with 44 professionals in Curitiba city. For each dentist was given a personal dosimeter to be used for 30 days. During this period, the number of radiographies and the length of the cable triggers of the X-ray equipment was registered and, the dosimeter´s dose was read. It was observed that the cables triggers meet regulatory standards and allow dentists to get the mean minimum distance of two meters from the radiation source in 93% of cases. Through analysis of the doses, it was concluded that occupational exposures of these workers are within the recommended threshold by regulatory 453/1998 of the Ministry of Health from Brazil. (author)

Bone X-Ray (Radiography)

Medline Plus

Full Text Available ... have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures that those parts of a patient's body not being imaged receive minimal radiation exposure. top of page What are the limitations of Bone X-ray (Radiography)? ...

Radiological protection procedures for industrial applications of computed radiography

International Nuclear Information System (INIS)

Aquino, Josilto Oliveira de

2009-03-01

Due to its very particular characteristics, industrial radiography is responsible for roughly half of the relevant accidents in nuclear industry, in developed as well as in developing countries, according to the International Atomic Energy Agency (IAEA). Thus, safety and radiological protection in industrial gamma radiography have been receiving especial treatment by regulatory authorities of most Member States. The main objective of the present work was to evaluate, from the radioprotection point of view, the main advantages of computed radiography (CR) for filmless industrial radiography. In order to accomplish this, both techniques, i.e. conventional and filmless computed radiography were evaluated and compared through practical studies. After the studies performed at the present work it was concluded that computed radiography significantly reduces the inherent doses, reflecting in smaller restricted areas and costs, with consequent improvement in radiological protection and safety. (author)

Clinical Evaluation of a Dual-Side Readout Technique Computed Radiography System in Chest Radiography of Premature Neonates

International Nuclear Information System (INIS)

Carlander, A.; Hansson, J.; Soederberg, J.; Steneryd, K.; Baath, M.

2008-01-01

Background: Recently, the dual-side readout technique has been introduced in computed radiography, leading to an increase in detective quantum efficiency (DQE) compared with the single-side readout technique. Purpose: To evaluate if the increase in DQE with the dual-side readout technique results in a higher clinical image quality in chest radiography of premature neonates at no increase in radiation dose. Material and Methods: Twenty-four chest radiographs of premature neonates were collected from both a single-side readout technique system and a double-side readout technique system. The images were processed in the same image-processing station in order for the comparison to be only dependent on the difference in readout technique. Five radiologists rated the fulfillment of four image quality criteria, which were based on important anatomical landmarks. The given ratings were analyzed using visual grading characteristics (VGC) analysis. Results: The VGC analysis showed that the reproduction of the carina with the main bronchi and the thoracic vertebrae behind the heart was better with the dual-side readout technique, whereas no significant difference for the reproduction of the central vessels or the peripheral vessels could be observed. Conclusions: The results indicate that the higher DQE of the dual-side readout technique leads to higher clinical image quality in chest radiography of premature neonates at no increase in radiation dose. Keywords: Digital radiography; lung; observer performance; pediatrics; thorax

Effect of comfort pads and incubator design on neonatal radiography

Energy Technology Data Exchange (ETDEWEB)

Jiang, Xia; Baad, Michael; Reiser, Ingrid; Feinstein, Kate A.; Lu, Zhengfeng [University of Chicago Medicine, Department of Radiology, Chicago, IL (United States)

2016-01-15

There has been increasing interest in patient dose reduction in neonatal intensive care units. Removing comfort pads for radiography has been identified as a potential means to decrease patient dose. To assess the effect of comfort pads and support trays on detector entrance exposure (DEE) and image quality for neonatal radiography, and its implication for patient dose. Comfort pads and support trays from three incubator and warmer systems were examined. The attenuation of the primary beam by these structures was measured using a narrow beam geometry. Their effect on DEE and image quality was then assessed using typical neonatal chest radiography techniques with three configurations: (1) both the comfort pad and support included in the beam, (2) only the support tray included and (3) both the comfort pad and support tray removed. Comfort pads and support trays were found to attenuate the primary beam by 6-15%. Eliminating these structures from the X-ray beam's path was found to increase the detector entrance exposure by 28-36% and increase contrast-to-noise ratio by more than 21%, suggesting room for patient dose reduction when the same image quality is maintained. Comfort pads and tray support devices can have a considerable effect on DEE and image quality, with large variations among different incubator designs. Positioning the image detector directly underneath neonatal patients for radiography is a potential means for patient dose reduction. However, such benefit should be weighed against the risks of moving the patient. (orig.)

Effect of comfort pads and incubator design on neonatal radiography

International Nuclear Information System (INIS)

Jiang, Xia; Baad, Michael; Reiser, Ingrid; Feinstein, Kate A.; Lu, Zhengfeng

2016-01-01

There has been increasing interest in patient dose reduction in neonatal intensive care units. Removing comfort pads for radiography has been identified as a potential means to decrease patient dose. To assess the effect of comfort pads and support trays on detector entrance exposure (DEE) and image quality for neonatal radiography, and its implication for patient dose. Comfort pads and support trays from three incubator and warmer systems were examined. The attenuation of the primary beam by these structures was measured using a narrow beam geometry. Their effect on DEE and image quality was then assessed using typical neonatal chest radiography techniques with three configurations: (1) both the comfort pad and support included in the beam, (2) only the support tray included and (3) both the comfort pad and support tray removed. Comfort pads and support trays were found to attenuate the primary beam by 6-15%. Eliminating these structures from the X-ray beam's path was found to increase the detector entrance exposure by 28-36% and increase contrast-to-noise ratio by more than 21%, suggesting room for patient dose reduction when the same image quality is maintained. Comfort pads and tray support devices can have a considerable effect on DEE and image quality, with large variations among different incubator designs. Positioning the image detector directly underneath neonatal patients for radiography is a potential means for patient dose reduction. However, such benefit should be weighed against the risks of moving the patient. (orig.)

Apparatus for gamma radiography

International Nuclear Information System (INIS)

1983-06-01

The aim of the present standard is to fix the rules for the construction of gamma radiography instrumentation without prejudice to the present regulations. These apparatus have to be fitted with only sealed sources conformable to the experimental standard M 61-002. The present standard agrees with the international standard ISO 3999 of 1977 dealing with the same subject. Nevertheless, it is different on the three main following points: it does not accept the same limits of absorbed dose rates in the air calculated on the external surface of projectors; it precribes tightness, bending, crushing and tensile tests for some components of the gamma radiography it prescribes tests of endurance and resistance to breaking for the locking systems of the gamma radiography apparatus. The present standard also specifies the following points: symbols and indications to put on projectors and on the source-holder; identification of the source contained in the projector; and, accompanying documents. The regulation references are given in annexe [fr

Scatter and transmission doses from several pediatric X-ray examinations in a nursery

International Nuclear Information System (INIS)

Burrage, John W.; Rampant, Peter L.; Beeson, Brendan P.

2003-01-01

While several studies have investigated the dose from scattered radiation from X-ray procedures in a pediatric nursery, they examined scatter from chest procedures only, or the types of examination were not specified. The aim of this study was to collect scatter and transmission data from several types of X-ray examinations. Using a ''newborn'' anthropomorphic phantom and an ion chamber, a series of scatter and transmission dose measurements were performed using typical exposure factors for chest, chest and abdomen, skull, skeletal long bone and spine procedures. The phantom was inside a crib for all exposures. The maximum scatter dose measured at 1 m from the field center was about 0.05 μGy per exposure for lateral skulls. Transmission doses for lateral exams were around 0.1 μGy per exposure at 1 m from the isocenter. The study demonstrated that scatter dose to other patients in a neonatal unit is not significant, assuming the distance between adjacent cribs is in the order of 1 m. Transmission doses are also low provided the beam is fully intercepted by the cassette. For an average workload the dose received by imaging technologists would be small. (orig.)

Patient dosimetry during chest radiography

International Nuclear Information System (INIS)

Ciraj-Bjelac, O.; Kosutic, D.; Markovic, S.

2004-01-01

Reasons for the variation in patient doses from chest radiography procedure were investigated by assessing entrance skin doses from kerma-area product measurements. Data were collected from seven x-ray tubes in five hospitals involving 259 adult patients. The third quartile value was 0.81 mGy compared to general reference level of 0.30 mGy. The applied tube potential was main contributor to patient dose variation. If department use at least 90 k Vp, the mean entrance surface dose would be reduced ut to factor six. Modification of departmental procedure is correct approach for dose reduction in diagnostic radiology. (author) [sr

Apparatus for proton radiography

International Nuclear Information System (INIS)

Martin, R.L.

1976-01-01

An apparatus for effecting diagnostic proton radiography of patients in hospitals comprises a source of negative hydrogen ions, a synchrotron for accelerating the negative hydrogen ions to a predetermined energy, a plurality of stations for stripping extraction of a radiography beam of protons, means for sweeping the extracted beam to cover a target, and means for measuring the residual range, residual energy, or percentage transmission of protons that pass through the target. The combination of information identifying the position of the beam with information about particles traversing the subject and the back absorber is performed with the aid of a computer to provide a proton radiograph of the subject. In an alternate embodiment of the invention, a back absorber comprises a plurality of scintillators which are coupled to detectors. 10 claims, 7 drawing figures

Radiation protection in technical radiography

International Nuclear Information System (INIS)

Thiele, H.

1980-01-01

In on-site inspections, e.g. double-plate radiography of circumferential pipe welds Ir-192 is most frequently used. Methods, controlled area, possible personnel doses, and radiation protection measures for the inspection and construction personnel are briefly discussed. (HP) [de

Dental radiography exposure of the Hiroshima and Nagasaki populations

International Nuclear Information System (INIS)

Antoku, Shigetoshi; Hoshi, Masaharu; Russell, W.J.

1987-04-01

Dental radiography doses in Hiroshima and Nagasaki were estimated using doses measured by a thermoluminescent dosimeter and a phantom, and survey data from dental hospitals and clinics in Hiroshima and Nagasaki. Doses to organs, including the lens, pituitary fossa, thyroid gland, and skin were calculated. Average doses per examination to these body sites were calculated using data obtained during a two-week survey in both cities. The mean caput doses were calculated from the data indicating frequency per year, and were tabulated by organ, age, teeth examined, type of examination, population, sex, and city. No significant difference was observed by age, population, sex, or city. Currently, the doses incurred during dental radiography may not be sufficiently high to cause bias in the assessments for late radiation effects among atomic bomb survivors. However, the mean caput thyroid doses of 62 mrad and 67 mrad in Hiroshima and Nagasaki, respectively, cannot be ignored from the standpoint of their potential in contributing to radiation-induced carcinogenesis. (author)

A methodology for radiological accidents analysis in industrial gamma radiography

International Nuclear Information System (INIS)

Silva, F.C.A. da.

1990-01-01

A critical review of 34 published severe radiological accidents in industrial gamma radiography, that happened in 15 countries, from 1960 to 1988, was performed. The most frequent causes, consequences and dose estimation methods were analysed, aiming to stablish better procedures of radiation safety and accidents analysis. The objective of this work is to elaborate a radiological accidents analysis methodology in industrial gamma radiography. The suggested methodology will enable professionals to determine the true causes of the event and to estimate the dose with a good certainty. The technical analytical tree, recommended by International Atomic Energy Agency to perform radiation protection and nuclear safety programs, was adopted in the elaboration of the suggested methodology. The viability of the use of the Electron Gamma Shower 4 Computer Code System to calculate the absorbed dose in radiological accidents in industrial gamma radiography, mainly at sup(192)Ir radioactive source handling situations was also studied. (author)

Projection radiography and tomography

International Nuclear Information System (INIS)

Tobias, C.A.; Fabrikant, J.I.; Benton, E.V.; Holley, W.R.

1980-01-01

Our program on heavy-ion radiography began soon after heavy ions were accelerated to high energies. Heavy ions are capable of very high electron density discrimination combined with good radial image resolution and low dose. Since heavy-ion beams produce many secondries, plastic nuclear detectors have an advantage for recording heavy-ion images. Projection imaging is now a practical technique that can resolve density differences between normal tissue and tumor tissue in some cases in which X rays could not make a distinction. Initial attempts at heavy-ion tomography also indicate potential for high resolution in this field. The physical basis for heavy-ion radiography and tomographic reconstruction studies are discussed in detail

TU-F-9A-01: Balancing Image Quality and Dose in Radiography

International Nuclear Information System (INIS)

Peck, D; Pasciak, A

2014-01-01

Emphasis is often placed on minimizing radiation dose in diagnostic imaging without a complete consideration of the effect on image quality, especially those that affect diagnostic accuracy. This session will include a patient image-based review of diagnostic quantities important to radiologists in conventional radiography, including the effects of body habitus, age, positioning, and the clinical indication of the exam. The relationships between image quality, radiation dose, and radiation risk will be discussed, specifically addressing how these factors are affected by image protocols and acquisition parameters and techniques. This session will also discuss some of the actual and perceived radiation risk associated with diagnostic imaging. Regardless if the probability for radiation-induced cancer is small, the fear associated with radiation persists. Also when a risk has a benefit to an individual or to society, the risk may be justified with respect to the benefit. But how do you convey the risks and the benefits to people? This requires knowledge of how people perceive risk and how to communicate the risk and the benefit to different populations. In this presentation the sources of errors in estimating risk from radiation and some methods used to convey risks are reviewed. Learning Objectives: Understand the image quality metrics that are clinically relevant to radiologists. Understand how acquisition parameters and techniques affect image quality and radiation dose in conventional radiology. Understand the uncertainties in estimates of radiation risk from imaging exams. Learn some methods for effectively communicating radiation risk to the public

TU-F-9A-01: Balancing Image Quality and Dose in Radiography

Energy Technology Data Exchange (ETDEWEB)

Peck, D [Henry Ford Health System, Detroit, MI (United States); Pasciak, A [University of Tennessee Medical Center, Knoxville, TN (United States)

2014-06-15

Emphasis is often placed on minimizing radiation dose in diagnostic imaging without a complete consideration of the effect on image quality, especially those that affect diagnostic accuracy. This session will include a patient image-based review of diagnostic quantities important to radiologists in conventional radiography, including the effects of body habitus, age, positioning, and the clinical indication of the exam. The relationships between image quality, radiation dose, and radiation risk will be discussed, specifically addressing how these factors are affected by image protocols and acquisition parameters and techniques. This session will also discuss some of the actual and perceived radiation risk associated with diagnostic imaging. Regardless if the probability for radiation-induced cancer is small, the fear associated with radiation persists. Also when a risk has a benefit to an individual or to society, the risk may be justified with respect to the benefit. But how do you convey the risks and the benefits to people? This requires knowledge of how people perceive risk and how to communicate the risk and the benefit to different populations. In this presentation the sources of errors in estimating risk from radiation and some methods used to convey risks are reviewed. Learning Objectives: Understand the image quality metrics that are clinically relevant to radiologists. Understand how acquisition parameters and techniques affect image quality and radiation dose in conventional radiology. Understand the uncertainties in estimates of radiation risk from imaging exams. Learn some methods for effectively communicating radiation risk to the public.

Practical evaluation of clinical image quality (4). Determination of image quality in digital radiography system

International Nuclear Information System (INIS)

Katayama, Reiji

2016-01-01

Recently, for medical imaging, digital radiography systems are widely used in clinical practices. However, a study in the past reported that a patient radiation exposure level by digital radiography is in fact not lower than that by analog radiography system. High level of attention needs to be paid for over-exposure when using the conventional analog radiography with a screen and a film, as it results in high density of the film. However, for digital radiography systems, since the automatic adjusting function of image density is equipped with them, no attention for radiation dose need to be paid. Thus technologists tend to be careless and results in higher chance for over-exposure. Current digital radiography systems are high-performance in the image properties and capable of patient dose reduction. Especially, the image quality of the flat panel detector system is recognized, higher than that of the computed radiography system by imaging plates, in both objective and subjective evaluations. Therefore, we technologists are responsible for optimizing the balance between the image quality of the digital radiogram and the radiation dose required for each case. Moreover, it is also required for us as medical technologists to make effective use of such evaluation result of medical images for patients. (author)

Assessment of whole-body occupational radiation exposure in industrial radiography practices in Bangladesh during 2010-2014

International Nuclear Information System (INIS)

Rahman, M.S.; Hoque, A.; Khan, R.K.; Siraz, M.M.M.; Begum, A.

2016-01-01

Presently, ten industrial radiography facilities are operating in Bangladesh using X-ray or gamma-ray sources. During the last 5-year, 14 industrial radiography facilities were received individual monitoring service using thermoluminescent dosimeters (TLDs) from the Health Physics Division (HPD), Atomic Energy Centre, Dhaka under Bangladesh Atomic Energy Commission. HPD is the only individual monitoring service provider in Bangladesh due to external sources of ionizing radiation. The number of monitored industrial radiography facilities ranged from 7 to 14 while the number of worker ranged from 72 to 133 during the study period. The annual average effective doses received from external radiation in industrial radiography workers and the distributions of the annual effective doses by dose intervals are presented. The distribution of the occupational doses shows that the majority (about 75 %) of workers received doses below 1 mSv for the last 5-years. Even though, very few workers (about 1%) received doses higher than average annual dose limit (20 mSv), but no workers received doses higher than 100 mSv in 5 consecutive years. The average annual effective dose of industrial radiography workers in Bangladesh is higher than the corresponding values in Tanzania, Greece, Poland, Australia, UK and lower than in Bosnia and Herzegovina, USA and Canada. However, the average annual effective dose is comparable to the corresponding values in China, Brazil, Germany and India. The status and trends in occupational doses show that radiation protection situation at the majority of the workplace were satisfactory. In spite of that, additional measures are required due to big differences observed in the maximum individual doses over the last 5-year. (author)

Assessment of whole-body occupational radiation exposure in industrial radiography practices in Bangladesh during 2010-2014

Energy Technology Data Exchange (ETDEWEB)

Rahman, M.S.; Hoque, A.; Khan, R.K.; Siraz, M.M.M., E-mail: msrahman74@hotmail.com [Health Physics Division, Atomic Energy Centre, Shahbag, Dhaka (Bangladesh); Begum, A. [Physical Science Division, Bangladesh Atomic Energy Commission, Dhaka (Bangladesh)

2016-07-01

Presently, ten industrial radiography facilities are operating in Bangladesh using X-ray or gamma-ray sources. During the last 5-year, 14 industrial radiography facilities were received individual monitoring service using thermoluminescent dosimeters (TLDs) from the Health Physics Division (HPD), Atomic Energy Centre, Dhaka under Bangladesh Atomic Energy Commission. HPD is the only individual monitoring service provider in Bangladesh due to external sources of ionizing radiation. The number of monitored industrial radiography facilities ranged from 7 to 14 while the number of worker ranged from 72 to 133 during the study period. The annual average effective doses received from external radiation in industrial radiography workers and the distributions of the annual effective doses by dose intervals are presented. The distribution of the occupational doses shows that the majority (about 75 %) of workers received doses below 1 mSv for the last 5-years. Even though, very few workers (about 1%) received doses higher than average annual dose limit (20 mSv), but no workers received doses higher than 100 mSv in 5 consecutive years. The average annual effective dose of industrial radiography workers in Bangladesh is higher than the corresponding values in Tanzania, Greece, Poland, Australia, UK and lower than in Bosnia and Herzegovina, USA and Canada. However, the average annual effective dose is comparable to the corresponding values in China, Brazil, Germany and India. The status and trends in occupational doses show that radiation protection situation at the majority of the workplace were satisfactory. In spite of that, additional measures are required due to big differences observed in the maximum individual doses over the last 5-year. (author)

The effect of patient shield position on gonad dose during lumbar spine radiography

International Nuclear Information System (INIS)

Clancy, Conor L.; O'Reilly, Geraldine; Brennan, Patrick C.; McEntee, Mark F.

2010-01-01

Background: In an effort to standardise radiological practices in the Republic of Ireland, current legislation states that 'written protocols for every type of standard radiological practice shall be established'. In order to fulfil this requirement the Irish Medical Council recommends the protocols issued by the Commission of European Communitees (CEC) for adoption in the country. Whilst this document does provide good guidance with regard to various radiographic factors, patient shielding instructions are notably ambiguous. The aim of this study was to remove some of this ambiguity by defining the optimal method of positioning patient shielding in antero-posterior (AP) and lateral lumbar spine radiographic examinations. These projections were chosen on the basis of their area of coverage being in close to and in some cases including the reproductive organs. They also represent the highest source of collective population dose of any conventional radiographic examination carried out in the UK. Method: A dosimetry study was devised to establish organ dose to the male testes and female ovaries using various clinically advocated methodologies for positioning patient shielding these included: no apron; tube-side apron; receptor-side apron and a wrap-around apron. The study was carried out using a direct digital radiography unit, an anthropomorphic phantom, various lead aprons and lithium thermoluminescent dosimeters (TLD). Results: For the AP projection, a statistically significant testes dose reduction of 42% (p ≤ 0.01) was observed when a tube-sided apron was used. No testes dose reductions were noted for the lateral projection. Ovary dose savings were not observed for any of the shielding methods investigated. Conclusion: This study found that the testes dose in AP examinations was reduced by 42% when patient shielding was positioned inferior to the imaged field and on the tube-side of the patient. This result validates the shielding methods used at the majority

Absorbed bone marrow dose in certain dental radiographic techniques

International Nuclear Information System (INIS)

White, S.C.; Rose, T.C.

1979-01-01

The absorbed dose of radiation in the bone marrow of the region of the head and neck was measured during intraoral, panoramic, and cephalometric radiography. Panoramic radiography results in a dose a fifth or less than that from an intraoral survey. The use of rectangular collimation reduces the bone marrow absorbed dose from an intraoral survey by about 60%. Comparison of the doses from dental radiography with natural environmental radiation shows that an intraoral set of films results in the same total dose to the bone marrow as 65 days of background exposure. The use of rectangular collimation reduces this value to 25 days. Panoramic radiography results in significantly less irradiation, as it reduces the value to 14 days or fewer. Dental radiography thus involves exposures in the range of variation of natural environmental background values

Radiation exposure during equine radiography

International Nuclear Information System (INIS)

Ackerman, N.; Spencer, C.P.; Hager, D.A.; Poulos, P.W. Jr.

1988-01-01

All personnel present in the X-ray examination room during equine radiography were monitored using low energy direct reading ionization chambers (pockets dosimeters) worn outside the lead apron at neck level. The individuals' task and dosimeter readings were recorded after each examination. Average doses ranged from 0 to 6 mrad per study. The greatest exposures were associated with radiography of the shoulder and averaged less than 4 mrad. The individual extending the horse's limb was at greatest risk although the individual holding the horse's halter and the one making the X-ray exposure received similar exposures. A survey of the overhead tube assembly used for some of the X-ray examinations also was performed. Meter readings obtained indicated an asymetric dose distribution around the tube assembly, with the highest dose occurring on the side to which the exposure cord was attached. Although the exposures observed were within acceptable limits for occupational workers, we have altered our protocol and no longer radiograph the equine shoulder unless the horse is anesthetized. Continued use of the pocket dosimeters and maintenance of a case record of radiation exposure appears to make the technologists more aware of radiation hazards

Personnel exposures in industrial radiography

International Nuclear Information System (INIS)

Shenoy, K.S.; Patel, P.H.

1979-01-01

The manifold increase in production, and ease of availability of radioisotopes in India have been responsible for a tremendous increase in use of radioisotopes in industrial radiography during past fifteen years. Among various applications of radioisotopes the industrial radiography involves a large potential risk of occupational radiation exposures. The dose records of past fifteen years in respect of all radiation workers maintained by the Personnel Monitoring Group of Division of Radiological Protection of the Bhabha Atomic Research Centre, Bombay, have been analysed. Analysis of excessive exposure (exceeding 400 mrem/fortnight) reveals that this figure is increasing at an alarming rate among the radiation workers of this category. In spite of various regulatory controls the dose per person per week has remained higher as compared to the same in other categories. This combined with the increase in number of radiation workers every year would soon contribute significantly to the per capita dose for radiation workers. Use of adequately shielded fool-proof remote control equipment and training of all personnel in safe handling of radiation sources seem to be the only solution to arrest the rate of increase in personnel exposures of this category. (auth.)

Development of transmission dose estimation algorithm for in vivo dosimetry in high energy radiation treatment

International Nuclear Information System (INIS)

Yun, Hyong Geun; Shin, Kyo Chul; Hun, Soon Nyung; Woo, Hong Gyun; Ha, Sung Whan; Lee, Hyoung Koo

2004-01-01

In vivo dosimetry is very important for quality assurance purpose in high energy radiation treatment. Measurement of transmission dose is a new method of in vivo dosimetry which is noninvasive and easy for daily performance. This study is to develop a tumor dose estimation algorithm using measured transmission dose for open radiation field. For basic beam data, transmission dose was measured with various field size (FS) of square radiation field, phantom thickness (Tp), and phantom chamber distance (PCD) with a acrylic phantom for 6 MV and 10 MV X-ray. Source to chamber distance (SCD) was set to 150 cm. Measurement was conducted with a 0.6 cc Farmer type ion chamber. By using regression analysis of measured basic beam data, a transmission dose estimation algorithm was developed. Accuracy of the algorithm was tested with flat solid phantom with various thickness in various settings of rectangular fields and various PCD. In our developed algorithm, transmission dose was equated to quadratic function of log(A/P) (where A/P is area-perimeter ratio) and the coefficients of the quadratic functions were equated to tertiary functions of PCD. Our developed algorithm could estimate the radiation dose with the errors within ±0.5% for open square field, and with the errors within ±1.0% for open elongated radiation field. Developed algorithm could accurately estimate the transmission dose in open radiation fields with various treatment settings of high energy radiation treatment. (author)

Digital radiography of the chest in pediatric patients

International Nuclear Information System (INIS)

Puig, S.

2003-01-01

The hopes placed in digital radiography have been fulfilled only partly in pediatric radiology. Specifically, the option of gaining reduced radiation exposure in combination with a similar or even improved image quality was hard to realize. The only portable digital system available for a long time were storage phosphors which were disadvantaged by an extremely limited dose-quantum-efficiency (DQE) in comparison to digital flat panel detectors. New developments and the introduction of the dual-reading system led to image qualities comparable to film-screen-systems with high resolution and achievable without dose increase, sometimes even with dose reduction. A study using an animal model suggests that these systems can even be used in preterm infants with very low birth weights. A new portable flat panel detector by Canon may improve digital chest radiography in pediatric patients. (orig.) [de

Which technologies to replace gamma radiography?

International Nuclear Information System (INIS)

Zani-Demange, M.L.; Chauveau, D.

2012-01-01

Gamma radiography with iridium source is largely used in the industrial sector for the control of welds, tubes and pressure vessels as well as for monitoring corrosion. Hazards due to the handling of ionizing radiation sources (Ir 192 ) and constraints due to a more and more demanding regulations call for alternative methods. The French 'Institut de soudure' has led a 4-year long study (Alter-X project) and has identified 3 alternative methods for the iridium gamma radiography: -) the TOFD (Time Of Flight Diffraction) which is based on the analysis of the diffraction of ultrasound waves on the edges of defects; -) phased array ultrasound which is based on a series of elementary sensors that can be handled in an individual manner by specific electronics, the sweeping is no more manual but electronic and enables the operator to localize and size defects deep under the surface; -) digit radiography that is a common radiography in which the film is replaced by a re-usable phosphorus screen that is more sensitive and can be easily digitalized and has no need for a chemical treatment to be read. Digit radiography used with Se 75 (another gamma emitter) gives comparable or even better results than with Ir 192 but with a dose rate cut by half at least. (A.C.)

Industrial Radiography Safety in Australia

International Nuclear Information System (INIS)

Hockings, Colin

2006-01-01

cumbersome and often exceeds the prescribed OH and S single person lifting limits. The role of industrial radiography has expanded to inspect not only welds and castings, so that it now includes inspection of assembled and processed goods ranging from automotive air-bags to canned food. It is also used in security systems at airports and other facilities. Almost all these applications use cabinet systems which are rarely the subject of serious radiation incidents or accidents. Gamma ray inspection no longer uses radium. The most common radio-isotopes in use now are Cobalt 60 and Iridium 192. Their freedom from the need for an electrical power supply; their high radiation energy and the ability to place a source in positions of limited physical access, ensures the ongoing attraction of the method. The useful activity ranges of typical sources vary according to their application and the effect on total inspection costs. Common source activities in Australia range between 185 and 370 GBq for Cobalt 60; and between 1500 and 3700 GBq for Iridium 192. Outside Australia however there are recent reports of routine industrial radiography using more than 5500 GBq of Iridium 192. Thus it can be appreciated that any radiation accidents involving these high activity sources have the potential for significant radiation doses. Personal Dose Data: ARPANSA and its predecessor, the Australian Radiation Laboratory, has been providing a personal radiation monitoring service for some time, and releases a summary report every few years (ARPANSA/TR 139, ARL/TR 121, ARL/TR 107). The selected data shown in Table 2 indicate a downward trend in occupational doses received by industrial radiographers working in open site situations, which are potentially the most hazardous. This trend is encouraging, especially when the number of industrial radiographers is increasing. A comparison of the ARPANSA data indicate that whilst the average Australian industrial radiographer's annual dose is higher than the

X-ray absorption radiography for high pressure shock wave studies

Science.gov (United States)

Antonelli, L.; Atzeni, S.; Batani, D.; Baton, S. D.; Brambrink, E.; Forestier-Colleoni, P.; Koenig, M.; Le Bel, E.; Maheut, Y.; Nguyen-Bui, T.; Richetta, M.; Rousseaux, C.; Ribeyre, X.; Schiavi, A.; Trela, J.

2018-01-01

The study of laser compressed matter, both warm dense matter (WDM) and hot dense matter (HDM), is relevant to several research areas, including materials science, astrophysics, inertial confinement fusion. X-ray absorption radiography is a unique tool to diagnose compressed WDM and HDM. The application of radiography to shock-wave studies is presented and discussed. In addition to the standard Abel inversion to recover a density map from a transmission map, a procedure has been developed to generate synthetic radiographs using density maps produced by the hydrodynamics code DUED. This procedure takes into account both source-target geometry and source size (which plays a non negligible role in the interpretation of the data), and allows to reproduce transmission data with a good degree of accuracy.

Digital image intensifier radiography. One year's experience with a Polytron system

International Nuclear Information System (INIS)

Busch, H.P.; Lehmann, K.J.; Georgi, M.

1989-01-01

Since January 1988, digital image intensifier radiography has been used in the Clinic in Mannheim for DSA examinations and also in place of conventional screen/film examinations. Measurements have shown that compared with 100 mm and film/screen formats, digital radiography has poorer spatial resolution, but improved contrast resolution. The most common use of digital radiography was for examinations of the gastrointestinal tract. Using the demonstration of the mucosal fine relief pattern as a criterion of image quality, digital image intensifier radiography was able to achieve this satisfactorily. Comparison with film/screen examinations showed no loss of diagnostic information. Advantages of image intensifier radiography are reduced radiation dose, the possibility of postprocessing and economy. On the basis of 399 examinations, digital image intensifier radiography is now firmly established as part of the daily routine of the Mannheim Clinic. (orig.) [de

Modification of transmission dose algorithm for irregularly shaped radiation field and tissue deficit

Energy Technology Data Exchange (ETDEWEB)

Yun, Hyong Geon; Shin, Kyo Chul [Dankook Univ., College of Medicine, Seoul (Korea, Republic of); Huh, Soon Nyung; Woo, Hong Gyun; Ha, Sung Whan [Seoul National Univ., College of Medicine, Seoul (Korea, Republic of); Lee, Hyoung Koo [The Catholic Univ., College of Medicine, Seoul (Korea, Republic of)

2002-07-01

Algorithm for estimation of transmission dose was modified for use in partially blocked radiation fields and in cases with tissue deficit. The beam data was measured with flat solid phantom in various conditions of beam block. And an algorithm for correction of transmission dose in cases of partially blocked radiation field was developed from the measured data. The algorithm was tested in some clinical settings with irregular shaped field. Also, another algorithm for correction of transmission dose for tissue deficit was developed by physical reasoning. This algorithm was tested in experimental settings with irregular contours mimicking breast cancer patients by using multiple sheets of solid phantoms. The algorithm for correction of beam block could accurately reflect the effect of beam block, with error within {+-}1.0%, both with square fields and irregularly shaped fields. The correction algorithm for tissue deficit could accurately reflect the effect of tissue deficit with errors within {+-}1.0% in most situations and within {+-}3.0% in experimental settings with irregular contours mimicking breast cancer treatment set-up. Developed algorithms could accurately estimate the transmission dose in most radiation treatment settings including irregularly shaped field and irregularly shaped body contour with tissue deficit in transmission dosimetry.

Modification of transmission dose algorithm for irregularly shaped radiation field and tissue deficit

International Nuclear Information System (INIS)

Yun, Hyong Geon; Shin, Kyo Chul; Huh, Soon Nyung; Woo, Hong Gyun; Ha, Sung Whan; Lee, Hyoung Koo

2002-01-01

Algorithm for estimation of transmission dose was modified for use in partially blocked radiation fields and in cases with tissue deficit. The beam data was measured with flat solid phantom in various conditions of beam block. And an algorithm for correction of transmission dose in cases of partially blocked radiation field was developed from the measured data. The algorithm was tested in some clinical settings with irregular shaped field. Also, another algorithm for correction of transmission dose for tissue deficit was developed by physical reasoning. This algorithm was tested in experimental settings with irregular contours mimicking breast cancer patients by using multiple sheets of solid phantoms. The algorithm for correction of beam block could accurately reflect the effect of beam block, with error within ±1.0%, both with square fields and irregularly shaped fields. The correction algorithm for tissue deficit could accurately reflect the effect of tissue deficit with errors within ±1.0% in most situations and within ±3.0% in experimental settings with irregular contours mimicking breast cancer treatment set-up. Developed algorithms could accurately estimate the transmission dose in most radiation treatment settings including irregularly shaped field and irregularly shaped body contour with tissue deficit in transmission dosimetry

Neutron radiography

International Nuclear Information System (INIS)

Hrdlicka, Z.

1977-01-01

Neutron radiography is a radiographic method using a neutron beam of a defined geometry. The neutron source usually consists of a research reactor, a specialized neutron radiography reactor or the 252 Cf radioisotope source. There are two types of the neutron radiography display system, viz., a system producing neutron radiography images by a photographic process or a system allowing a visual display, eg., using a television monitor. The method can be used wherever X-ray radiography is used except applications in the radiography of humans. The neutron radiography unit at UJV uses the WWR-S reactor as the neutron source and both types of the above mentioned display system. (J.P.)

Patient exposure during plain radiography and mammography in Japan in 1974-2014

International Nuclear Information System (INIS)

Matsunaga, Yuta; Kawaguchi, Ai; Kobayashi, Kenichi; Kobayashi, Masanao; Asada, Yasuki; Minami, Kazuyuki; Suzuki, Shoichi; Chida, Koichi

2017-01-01

We investigated changes in the entrance skin dose (ESD) and the mean glandular dose (MGD) during plain radiography or mammography in Japan from 1974 to 2014. Surveys regarding the conditions used for plain radiography and mammography were performed throughout Japan in 1974, 1979, 1989, 1993, 1997, 2001, 2003, 2007, 2011 and 2014. The anatomical regions considered were categorised as follows: skull anteroposterior (AP), lumbar AP, lumbar lateral (LAT), pelvis (AP), ankle, chest posteroanterior (PA), Guthmann (lateral pelviography for pregnant women), infant hip joint and mammography. The doses for all anatomical regions decreased from 1974 to 1993. The MGD for mammography remained low from 1993 to 2014, and the ESDs for chest (PA) radiography trended upward. After the 2000's, the use of digital imaging increased in Japan. This is the first long-term study to examine changes in ESDs and MGDs in Japan. (authors)

Assessment of panoramic radiography as a national oral examination tool: review of the literature

Energy Technology Data Exchange (ETDEWEB)

Choi, Jin Woo [School of Dentistry, Seoul National University, Seoul (Korea, Republic of)

2011-03-15

The purpose of this review is to evaluate the possibility of panoramic radiography as a national oral examination tool. This report was carried out by review of the literatures. Panoramic radiography has sufficient diagnostic accuracy in dental caries, periodontal diseases, and other lesions. Also, the effective dose of panoramic radiography is lower than traditional full-mouth periapical radiography. Panoramic radiography will improve the efficacy of dental examination in national oral examination. However, more studies are required to evaluate the benefit, financial cost, and operation time and also to make selection criteria and quality management program.

Experimental system for high resolution X-ray transmission radiography

Czech Academy of Sciences Publication Activity Database

Jakůbek, J.; Holý, T.; Jakůbek, M.; Vavřík, Daniel; Vykydal, Z.

Volume 563, č. 1 (2006), s. 278-281 ISSN 0168-9002. [Intern. Workshop on Radiation Imaging Detectors /7./. Grenoble, 04.07.2005-07.07.2005] R&D Projects: GA MŠk(CZ) 1P04LA211; GA ČR(CZ) GA106/04/0567 Institutional research plan: CEZ:AV0Z20710524 Keywords : digital radiography * beam hardening * mikroradiography * roentgenogram quality Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 1.185, year: 2006

Artifacts in digital radiography

International Nuclear Information System (INIS)

Min, Jung Whan; Kim, Jung Min; Jeong, Hoi Woun

2015-01-01

Digital Radiography is a big part of diagnostic radiology. Because uncorrected digital radiography image supported false effect of Patient’s health care. We must be manage the correct digital radiography image. Thus, the artifact images can have effect to make a wrong diagnosis. We report types of occurrence by analyzing the artifacts that occurs in digital radiography system. We had collected the artifacts occurred in digital radiography system of general hospital from 2007 to 2014. The collected data had analyzed and then had categorize as the occurred causes. The artifacts could be categorized by hardware artifacts, software artifacts, operating errors, system artifacts, and others. Hardware artifact from a Ghost artifact that is caused by lag effect occurred most frequently. The others cases are the artifacts caused by RF noise and foreign body in equipments. Software artifacts are many different types of reasons. The uncorrected processing artifacts and the image processing error artifacts occurred most frequently. Exposure data recognize (EDR) error artifacts, the processing error of commissural line, and etc., the software artifacts were caused by various reasons. Operating artifacts were caused when the user did not have the full understanding of the digital medical image system. System artifacts had appeared the error due to DICOM header information and the compression algorithm. The obvious artifacts should be re-examined, and it could result in increasing the exposure dose of the patient. The unclear artifact leads to a wrong diagnosis and added examination. The ability to correctly determine artifact are required. We have to reduce the artifact occurrences by understanding its characteristic and providing sustainable education as well as the maintenance of the equipments

Artifacts in digital radiography

Energy Technology Data Exchange (ETDEWEB)

Min, Jung Whan [Dept. of Radiological Technology, Shin Gu University, Sungnam (Korea, Republic of); Kim, Jung Min [Dept. of Radiological Technology, Korea University, Seoul (Korea, Republic of); Jeong, Hoi Woun [Dept. of Radiological Technology, Beakseok Culture University, Cheonan (Korea, Republic of)

2015-12-15

Digital Radiography is a big part of diagnostic radiology. Because uncorrected digital radiography image supported false effect of Patient’s health care. We must be manage the correct digital radiography image. Thus, the artifact images can have effect to make a wrong diagnosis. We report types of occurrence by analyzing the artifacts that occurs in digital radiography system. We had collected the artifacts occurred in digital radiography system of general hospital from 2007 to 2014. The collected data had analyzed and then had categorize as the occurred causes. The artifacts could be categorized by hardware artifacts, software artifacts, operating errors, system artifacts, and others. Hardware artifact from a Ghost artifact that is caused by lag effect occurred most frequently. The others cases are the artifacts caused by RF noise and foreign body in equipments. Software artifacts are many different types of reasons. The uncorrected processing artifacts and the image processing error artifacts occurred most frequently. Exposure data recognize (EDR) error artifacts, the processing error of commissural line, and etc., the software artifacts were caused by various reasons. Operating artifacts were caused when the user did not have the full understanding of the digital medical image system. System artifacts had appeared the error due to DICOM header information and the compression algorithm. The obvious artifacts should be re-examined, and it could result in increasing the exposure dose of the patient. The unclear artifact leads to a wrong diagnosis and added examination. The ability to correctly determine artifact are required. We have to reduce the artifact occurrences by understanding its characteristic and providing sustainable education as well as the maintenance of the equipments.

Digital radiography: are the manufacturers' settings too high? Optimisation of the Kodak digital radiography system with aid of the computed radiography dose index

International Nuclear Information System (INIS)

Peters, Sinead E.; Brennan, Patrick C.

2002-01-01

Manufacturers offer exposure indices as a safeguard against overexposure in computed radiography, but the basis for recommended values is unclear. This study establishes an optimum exposure index to be used as a guideline for a specific CR system to minimise radiation exposures for computed mobile chest radiography, and compares this with manufacturer guidelines and current practice. An anthropomorphic phantom was employed to establish the minimum milliamperes consistent with acceptable image quality for mobile chest radiography images. This was found to be 2 mAs. Consecutively, 10 patients were exposed with this optimised milliampere value and 10 patients were exposed with the 3.2 mAs routinely used in the department of the study. Image quality was objectively assessed using anatomical criteria. Retrospective analyses of 717 exposure indices recorded over 2 months from mobile chest examinations were performed. The optimised milliampere value provided a significant reduction of the average exposure index from 1840 to 1570 (p<0.0001). This new ''optimum'' exposure index is substantially lower than manufacturer guidelines of 2000 and significantly lower than exposure indices from the retrospective study (1890). Retrospective data showed a significant increase in exposure indices if the examination was performed out of hours. The data provided by this study emphasise the need for clinicians and personnel to consider establishing their own optimum exposure indices for digital investigations rather than simply accepting manufacturers' guidelines. Such an approach, along with regular monitoring of indices, may result in a substantial reduction in patient exposure. (orig.)

Assessment and prevention of the professional risks in the operations of industrial radiography

International Nuclear Information System (INIS)

Pizzorno, M.; Paul, D.; Coletti, F.; Sari Minodier, I.; Azzopardi, G.; Klemenic, O.; Botta, A.

2006-01-01

Industrial radiography is a nocturnal activity, hazardous and little known; it is among the professions the most exposed to ionizing radiation. This study analyse the doses, received the industrial radiographers, their workplace conditions and organization of their tasks. Dosimetry observations on site, together with calculations using the Mercurad code, allowed mean values for reference doses for all the work (including transport, gammatron manipulation, collimator manipulation, shooting) to be established. These value were integrated into a table entitled 'reference doses' in order to provisionally evaluate the doses received by the operators. Distances for security zone demarcation, so as to forbid access to non exposed personnel during shooting, were evaluated. Assessment of the professional risks for industrial radiography, taking into account all the risks (radiological and others), has been made and is under evaluation. This led to measures for prevention based on the material used (collimator, tripod, gamma-stops), on the organization and the conditions of work (for example, time limits permitting a prior visit to the site and preparation for radiography, suitable scaffolding, sufficient lighting, siting of shootings). These prevention measure will be integrated into the new charter of good practice in industrial radiography in the Provence Alpes Cote d'Azur region (south of France). (authors)

Quality control in radiography: a primary responsibility of the technologist

International Nuclear Information System (INIS)

Koenig, G.F.

1973-01-01

The relationship between quality control in radiography and radiation protection is emphasized. Methods of dose reduction discussed are the 0.1 mm fractional focal spot, the use of high speed intensifying screens, and automatic exposure control. The need for recommendations for the establishment of improved systems of radiography is discussed. The development of revised educational concepts for radiologists is considered. (U.S.)

Dose-response relationships for environmentally mediated infectious disease transmission models.

Directory of Open Access Journals (Sweden)

Andrew F Brouwer

2017-04-01

Full Text Available Environmentally mediated infectious disease transmission models provide a mechanistic approach to examining environmental interventions for outbreaks, such as water treatment or surface decontamination. The shift from the classical SIR framework to one incorporating the environment requires codifying the relationship between exposure to environmental pathogens and infection, i.e. the dose-response relationship. Much of the work characterizing the functional forms of dose-response relationships has used statistical fit to experimental data. However, there has been little research examining the consequences of the choice of functional form in the context of transmission dynamics. To this end, we identify four properties of dose-response functions that should be considered when selecting a functional form: low-dose linearity, scalability, concavity, and whether it is a single-hit model. We find that i middle- and high-dose data do not constrain the low-dose response, and different dose-response forms that are equally plausible given the data can lead to significant differences in simulated outbreak dynamics; ii the choice of how to aggregate continuous exposure into discrete doses can impact the modeled force of infection; iii low-dose linear, concave functions allow the basic reproduction number to control global dynamics; and iv identifiability analysis offers a way to manage multiple sources of uncertainty and leverage environmental monitoring to make inference about infectivity. By applying an environmentally mediated infectious disease model to the 1993 Milwaukee Cryptosporidium outbreak, we demonstrate that environmental monitoring allows for inference regarding the infectivity of the pathogen and thus improves our ability to identify outbreak characteristics such as pathogen strain.

Comparative study between computed radiography and conventional radiography

International Nuclear Information System (INIS)

Noorhazleena Azaman; Khairul Anuar Mohd Salleh; Sapizah Rahim; Shaharudin Sayuti; Arshad Yassin; Abdul Razak Hamzah

2010-01-01

In Industrial Radiography, there are many criteria that need to be considered based on established standards to accept or reject the radiographic film. For conventional radiography, we need to consider the optical density by using the densitometer when viewing the film on the viewer. But in the computed radiography (CR) we need to evaluate and performed the analysis from the quality of the digital image through grey value. There are many factors that affected the digital image quality. One of the factors which are affected to the digital image quality in the image processing is grey value that related to the contrast resolution. In this work, we performed grey value study measurement on digital radiography systems and compared it with exposed films in conventional radiography. The test sample is a steel step wedge. We found out the contrast resolution is higher in Computed Radiography compared with Conventional Radiography. (author)

Problems associated with digital luminescence radiography in the neonate and young infant

International Nuclear Information System (INIS)

Arthur, R.J.; Pease, J.N.

1992-01-01

An evaluation of the Siemens Digiscan has been undertaken to determine whether digital luminescence radiography (DLR) could replace conventional radiography in the examination of the neonate and young infant. Whilst the overall image quality of the digital radiograph was consistently higher than for conventional radiography the difference was less marked than we had expected. Furthermore, the potential for reduction in radiation dose by reducing the repeat rate due to incorrect exposure was limited. The potential advantages of DLR have been critically examined in relationship to neonatal radiography and a number of problems encountered during the evaluation have been highlighted. (orig.)

Gonadal dosage during hip dysplasia radiography in the dog.

Science.gov (United States)

Wood, A K; Reynolds, K M; Leith, I S; Burns, P A

1977-01-01

Thermoluminescent dosemeters were used to estimate gonadal dosage during hip dysplasia radiography of labrador retriever dogs. The mean radiation dose to the unshielded testes was 100 millirad (mrad) and the estimated dose to the shielded testes was 9 mrad. It was considered unnecessary to shield the ovaries.

Diagnostic imaging in polytrauma: comparison of radiation exposure from whole-body MSCT and conventional radiography with organ-specific CT

International Nuclear Information System (INIS)

Wedegaertner, U.; Lorenzen, M.; Weber, C.; Adam, G.; Nagel, H.D.

2004-01-01

Purpose: To compare the radiation dose of whole-body multislice CT (MSCT) and conventional radiography with organ-specific CT in polytrauma. Materials and Methods: The whole-body MSCT encompassing brain, neck and midface, chest, abdomen and pelvis was performed on a Somatom Volume Zoom (Siemens). Conventional radiography consisted of chest and cervical, thoracic and lumbar spine in two views as well as pelvis. Polymat, Siemens. Three combinations of organ specific CT were chosen: CT examination of (1) head and cervical spine, (2) head, cervical spine and chest, (3) head, cervical spine and abdomen. The effective doses of whole-body MSCT and conventional radiography with organ-specific CT were calculated. Results: Effective doses were 20 mSv for whole-body MSCT, 2 mSv for conventional x-ray, and 5 mSv for combination (1), 8 mSv for combination (2) and (3) 16 mSv for combination (3) of the organ-specific CT. The ratio of radiation dose between whole-body MSCT and radiography was 10: 1. This ratio was reduced to 3: 1, 2: 1 and 1: 1 when a combination of radiography and CT was performed. Conclusions: Whole-body MSCT in polytrauma compared to conventional radiography with organ-specific CT induces a threefold increased dose in unfavorable situations and no increased dose in favorable situations. Nevertheless, routine use of whole-body MSCT should be critically evaluated and should be adapted to the clinical benefit. (orig.) [de

Reducing methods of patients exposed dose using auto exposure control system in digital radiography

Energy Technology Data Exchange (ETDEWEB)

Shin, Seong Gyu [Dept. of Diagnostic Radiology, Dong A University Medical Center, Busan (Korea, Republic of)

2013-06-15

This study was carried out to reduce patient dose through focus-detector distance, kilovoltage, and a combination of copper filters. In the C, L-spine lateral, Skull AP views were obtained by making changes of 60-100 kV in tube voltage and of 100-200 cm in focus-detector distance and by adding a copper filter when using an auto exposure control device in the digital radiography equipment. The incident dose showed 90 kV, 0.3 mmCu in C-spine lateral with 0.06 mGy under the condition of 200 cm; 100 kV, 0.3 mmCu with 0.40 mGy under the condition of 200 cm and 90 kV 0.3 mmCu in Skull AP with the lowest value of 0.24 mGy under the condition of 140 cm. It was observed that entrance surface dose decreased the most when was increased by 150 cm, 70 kV (C-spine lateral), 81 kV (L-spine lateral). It was also found out that as the between the focus-detector increased in the expansion of the video decreased but the difference was not significant when the distance was 180 cm or more. Skull AP showed the most reduction in the entrance surface dose when the tube voltage was changed by 80 kV, 0.1 mmCu, and 120 cm. Therefore, when using the automatic exposure control device, it is recommended to use the highest tube voltage if possible and to increase focus-detector distance at least by 150-200 cm in wall and 120-140 cm in table in consideration of the radiotechnologist's physical conditions, and to combine 0.1-0.3 mmCu and higher filters. It is thus expected to reduce patient dose by avoiding distortion of images and reducing the entrance surface dose.

Report of questionnaire concerning the conditions and exposure doses at thoracoabdominal radiography and CT

International Nuclear Information System (INIS)

2009-01-01

Japan Association of Radiological Technologists, at 2 years after its presentation of the Guideline for Medical Radiation Exposure (2006), made a questionnaire in the title on its homepage on Nov. 6-Dec. 5, 2008, and this paper is its report. The questionnaire asked the conditions and exposure doses at thoracoabdominal radiography and CT: in the former, asked were conditions like the machine/detector, tube voltage, filter, incident angle, entrance plane dose (EPD) (mGy) etc., and 237 facilities including 56 public hospitals and 15 universities answered. EPD calculated by numerical dose determination was found to be 0.22 and 0.76 mGy at the frontal and lateral thoracic projection, respectively, which were less than the upper limit defined in International Atomic Energy Agency (IAEA) guidance (0.4 and 1.5 mGy). However, doses in 6 and 2.6% of facilities at the respective projection exceeded the IAEA levels. EPD at the frontal abdominal projection calculated was 2.22 mGy, and all facilities met with the IAEA demand level (<10 mGy). In the CT questionnaire, conditions asked were the machine manufacturer/brand, scanning mode and range, tube voltage, rotation time, beam width and pitch, slice width, CTDIvol (CT Dose Index weighted/pitch) (mGy) and so on, which 212 facilities involving 58 public hospitals and 14 universities answered. CTDIvol was found to be 91.7 mGy at head CT which greatly exceeded the maximal levels of International Commission of Radiological Protection (ICRP), IAEA and the Association (60, 50 and 65 mGy, respectively). CTDIvol at thoracic CT was 15.2 mGy (no standard upper limit at present), and at abdominal CT, 20.0 mGy (the same as the Association level). The latter suggested the suitable dose setting at this CT. Thus the problem at head CT was much highlighted here. (K.T.)

Code of practice in industrial radiography

International Nuclear Information System (INIS)

Karma, S. E. M.

2010-12-01

The aim of this research is to developing a draft for a new radiation protection code of practice in industrial radiography without ignoring that one issued in 1998 and meet the current international recommendation. Another aim of this study was to assess the current situation of radiation protection in some of the industrial radiography department in Sudan. To achieve the aims of this study, a draft of a code of practice has been developed which is based on international and local relevant recommendations. The developed code includes the following main issues: regulatory responsibilities, radiation protection program and design of radiation installation. The practical part of this study includes scientific visits to two of industrial radiography departments in Sudan so as to assess the degree of compliance of that department with what state in the developed code. The result of each scientific visits revealed that most of the department do not have an effective radiation protection program and that could lead to exposure workers and public to unnecessary dose. Some recommendations were stated that, if implemented could improve the status of radiation protection in industrial radiography department. (Author)

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

International Nuclear Information System (INIS)

Suzuki, Shoichi; Fujii, Shigehisa; Asada, Yasuo; Orito, Takeo; Kamei, Tetsuya; Koga, Sukehiko

1998-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Shoichi; Fujii, Shigehisa; Asada, Yasuo; Orito, Takeo [Fujita Health Univ., Toyoake, Aichi (Japan). School of Health Science; Kamei, Tetsuya; Koga, Sukehiko

1998-12-01

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

Radiation dose reduction in the evaluation of scoliosis: an application of digital radiography

International Nuclear Information System (INIS)

Kushner, D.C.; Cleveland, R.H.; Herman, T.E.; Zaleske, D.J.; Ehrlich, M.G.; Correia, J.A.

1986-01-01

This report documents the clinical testing of scanning beam digital radiography as an imaging method in patients with scoliosis. This type of digital imaging requires a skin exposure of only 2.4 mR (0.619 microC/kg) per image, compared with the lowest possible posteroanterior screen-film exposure of 10 mR (2.58 microC/kg) at the chest and 60 mR (15.48 microC/kg) at the lumbar spine. Digital radiographic and screen-film images were obtained on multiple test objects and 273 patients. Scoliosis measurements using screen-film radiographs and digital radiographs were comparable to within a mean difference of 1 degrees at many different degrees of severity. The low-dose digital images were found to be useful and accurate for the detection and measurement of scoliosis after the first screen-film radiographs have excluded tumors and structural abnormalities

The effect of patient shield position on gonad dose during lumbar spine radiography

Energy Technology Data Exchange (ETDEWEB)

Clancy, Conor L.; O' Reilly, Geraldine [Department of Medical Physics and Bioengineering, Garden Hill House, St. James Hospital, James Street, Dublin (Ireland); Brennan, Patrick C. [Discipline of Medical Radiation Sciences, C42 - Cumberland Campus, The University of Sydney, Lidcombe NSW 2141 (Australia); McEntee, Mark F. [School of Medicine and Medical Science, Health Sciences Centre, University College Dublin, Belfield, Dublin 4 (Ireland)], E-mail: mark.mcentee@ucd.ie

2010-05-15

Background: In an effort to standardise radiological practices in the Republic of Ireland, current legislation states that 'written protocols for every type of standard radiological practice shall be established'. In order to fulfil this requirement the Irish Medical Council recommends the protocols issued by the Commission of European Communitees (CEC) for adoption in the country. Whilst this document does provide good guidance with regard to various radiographic factors, patient shielding instructions are notably ambiguous. The aim of this study was to remove some of this ambiguity by defining the optimal method of positioning patient shielding in antero-posterior (AP) and lateral lumbar spine radiographic examinations. These projections were chosen on the basis of their area of coverage being in close to and in some cases including the reproductive organs. They also represent the highest source of collective population dose of any conventional radiographic examination carried out in the UK. Method: A dosimetry study was devised to establish organ dose to the male testes and female ovaries using various clinically advocated methodologies for positioning patient shielding these included: no apron; tube-side apron; receptor-side apron and a wrap-around apron. The study was carried out using a direct digital radiography unit, an anthropomorphic phantom, various lead aprons and lithium thermoluminescent dosimeters (TLD). Results: For the AP projection, a statistically significant testes dose reduction of 42% (p {<=} 0.01) was observed when a tube-sided apron was used. No testes dose reductions were noted for the lateral projection. Ovary dose savings were not observed for any of the shielding methods investigated. Conclusion: This study found that the testes dose in AP examinations was reduced by 42% when patient shielding was positioned inferior to the imaged field and on the tube-side of the patient. This result validates the shielding methods used at the

Digital radiography versus conventional radiography during excretory urography: our experience

International Nuclear Information System (INIS)

Cervi, P.M.; Bighi, S.; Merlo, L.; Lupi, L.; Vita, G.

1990-01-01

The authors describe a computed radiographic system employed to generate and archive digital images in intravenous urography. For each exposure the system produces two digital images: the first (left image) simulates a conventional screen-film radiograph, the second (right image); enhances some spatial frequencies and emphasizes the margins of the structures. These images can be modified in their chief parameters and then printed by a laser-printer and archived on optical disks. Four experienced radiologists evaluated digital images with regard to some chief diagnostic parameters and, in 50 patients, they compared digital images with conventional screen-film radiographs and submitted the results to statistical analysis. For some of the chosen parameters, particularly for the evaluation of renal margins before and after contrast medium injection, digital images gave statistically better results than conventional films, while, no statistically significant different was observed for the other parameters. From the results of this preliminary study digital radiography was found to be useful in intravenous urography by reducing the patient's exposition dose, by always obtaining images of good quality, and by enhancing some particular features of the standard image; on the other hand there were many unsolved problems regarding the communicating and archiving system (PACS), because of the slowness of the image transfer procedure, difficulties in data transmission and complexity of referential procedures

Evaluation of automatic exposure control system chamber for the dose optimization when examining pelvic in digital radiography.

Science.gov (United States)

Kim, Sung-Chul; Lee, Hae-Kag; Lee, Yang-Sub; Cho, Jae-Hwan

2015-01-01

We found a way to optimize the image quality and reduce the exposure dose of patients through the proper activity combination of the automatic exposure control system chamber for the dose optimization when examining the pelvic anteroposterior side using the phantom of the human body standard model. We set 7 combinations of the chamber of automatic exposure control system. The effective dose was yielded by measuring five times for each according to the activity combination of the chamber for the dose measurement. Five radiologists with more than five years of experience evaluated the image through picture archiving and communication system using double blind test while classifying the 6 anatomical sites into 3-point level (improper, proper, perfect). When only one central chamber was activated, the effective dose was found to be the highest level, 0.287 mSv; and lowest when only the top left chamber was used, 0.165 mSv. After the subjective evaluation by five panel members on the pelvic image was completed, there was no statistically meaningful difference between the 7 chamber combinations, and all had good image quality. When testing the pelvic anteroposterior side with digital radiography, we were able to reduce the exposure dose of patients using the combination of the top right side of or the top two of the chamber.

Demonstration of the self-magnetic-pinch diode as an X-ray source for flash core-punch radiography

International Nuclear Information System (INIS)

Cordova, Steve Ray; Rovang, Dean Curtis; Portillo, Salvador; Oliver, Bryan Velten; Bruner, Nichelle Lee; Ziska, Derek Raymond

2007-01-01

Minimization of the radiographic spot size and maximization of the radiation dose is a continuing long-range goal for development of electron beam driven X-ray radiography sources. In collaboration with members of the Atomic Weapons Establishment(AWE), Aldermaston UK, the Advanced Radiographic Technologies Dept. 1645 is conducting research on the development of X-ray sources for flash core-punch radiography. The Hydrodynamics Dept. at AWE has defined a near term radiographic source requirement for scaled core-punch experiments to be 250 rads(at)m with a 2.75 mm source spot-size. As part of this collaborative effort, Dept. 1645 is investigating the potential of the Self-Magnetic-Pinched (SMP) diode as a source for core-punch radiography. Recent experiments conducted on the RITS-6 accelerator [1,2] demonstrated the potential of the SMP diode by meeting and exceeding the near term radiographic requirements established by AWE. During the demonstration experiments, RITS-6 was configured with a low-impedance (40 (Omega)) Magnetically Insulated Transmission Line (MITL), which provided a 75-ns, 180-kA, 7.5-MeV forward going electrical pulse to the diode. The use of a low-impedance MITL enabled greater power coupling to the SMP diode and thus allowed for increased radiation output. In addition to reconfiguring the driver (accelerator), geometric changes to the diode were also performed which allowed for an increase in dose production without sacrificing the time integrated spot characteristics. The combination of changes to both the pulsed power driver and the diode significantly increased the source x-ray intensity

Study of the equivalent dose distribution in organs and tissues using periapical odontological radiography; Estudo da distribuição de dose equivalente em órgãos e tecidos em procedimento de radiografia odontológica periapical

Energy Technology Data Exchange (ETDEWEB)

Santos, H.F.S.; Cipeli, J.F.; Fortes, M.A.B.; Federico, C.A., E-mail: hannasantana.f@gmail.com [Instituto de Estudos Avançados (IEAv), São José dos Campos, SP (Brazil). Divisão de Física Aplicada; Bissoli, C.F. [Universidade Paulista (UNIP), São José dos Campos, SP (Brazil)

2017-07-01

In this article presents a study of the doses obtained in periapical odontological radiography in main tissues of the head, using thermoluminescent dosemeters of type TLD-700H applied to a anthropomorphic simulator. The results indicate that the skin and salivary glands received the highest doses and the risk of calculated injury was 1.44 x 10{sup -6} Sv{sup -1} per radiograph.

What do recent epidemiological studies tell us about the risk of cancer from radiation doses typical of diagnostic radiography?

International Nuclear Information System (INIS)

Harbron, R.W.

2016-01-01

The last five years have seen unprecedented efforts to gain further understanding of the cancer risks following exposure to radiation doses below 100 mGy. Research has focused on occupationally exposed groups, populations exposed to elevated background radiation levels and children undergoing computed tomography scans. This review summarises the main findings of these studies and discusses the implications for diagnostic radiography. On balance, recent studies strengthen the association between radiation exposure at diagnostic dose levels and the risk of developing cancer at low doses. Although subject to considerable uncertainties, the risks to patients and staff from exposure to X-rays at diagnostic dose levels appear to be small, but non-zero. Despite the improved statistical power of recent studies, a number of shortcomings are apparent. These include dosimetric uncertainties and the potential confounding effects of cancer pre-disposing conditions and pre-existing tumours. - Highlights: • The risk of cancer from radiation doses below around 100 mGy is uncertain. • A number of new studies have been published with reasonably high statistical power. • These studies strengthen the association between X-rays and cancer at low doses. • Large uncertainties remain, however.

Evaluation of a Noise Reduction Procedure for Chest Radiography

Science.gov (United States)

Fukui, Ryohei; Ishii, Rie; Kodani, Kazuhiko; Kanasaki, Yoshiko; Suyama, Hisashi; Watanabe, Masanari; Nakamoto, Masaki; Fukuoka, Yasushi

2013-01-01

Background The aim of this study was to evaluate the usefulness of noise reduction procedure (NRP), a function in the new image processing for chest radiography. Methods A CXDI-50G Portable Digital Radiography System (Canon) was used for X-ray detection. Image noise was analyzed with a noise power spectrum (NPS) and a burger phantom was used for evaluation of density resolution. The usefulness of NRP was evaluated by chest phantom images and clinical chest radiography. We employed the Bureau of Radiological Health Method for scoring chest images while carrying out our observations. Results NPS through the use of NRP was improved compared with conventional image processing (CIP). The results in image quality showed high-density resolution through the use of NRP, so that chest radiography examination can be performed with a low dose of radiation. Scores were significantly higher than for CIP. Conclusion In this study, use of NRP led to a high evaluation in these so we are able to confirm the usefulness of NRP for clinical chest radiography. PMID:24574577

Trends that have influenced the Swedish radiography profession over the last four decades

International Nuclear Information System (INIS)

Andersson, B.T.; Lundgren, S.M.; Lundén, M.

2017-01-01

Introduction: The expansion of the radiography profession in recent decades has widened the scope of radiographic practice. This has raised questions about which trends have had an impact on the profession over the years. The study aim was to explore trends that have influenced the radiography profession over the last four decades. Methods: A qualitative design was used. Eleven focus group interviews inspired by the Scenario Planning Method were conducted at 11 diagnostic radiology departments in public hospitals in Sweden. The target group consisted of 48 registered radiographers. To analyse the data, qualitative content analysis was used. Results: Thematic data analysis revealed three broad categories; technological development and radiation doses, current status of the radiography profession and specialisation leading to expert knowledge. Each category derived from two or three sub-categories. Conclusion: The results demonstrate significant trends of influences on the radiography profession in Sweden over the last four decades. New methods and technology and control of radiation doses have had a favourable effect on the development of the radiography profession. Nevertheless, current status such as shortage of radiographers has had an adverse way. Specialisation leading to expert knowledge has an influence on career advancement and a specialist education regulated by the law, might be a prerequisite for the development of the radiography profession. - Highlights: • Scenario Planning Method, a relatively underutilised methodology, was used. • The findings report the influencing trends perceived by Swedish radiographers. • Technological development and radiation dose awareness impacted the profession. • Shortage, work shifting and higher independency influenced the profession. • Expert knowledge affects career advancement and requests specialist education.

Pediatric digital radiography education for radiologic technologists: current state

International Nuclear Information System (INIS)

Morrison, Gregory; Culbertson, John; Carbonneau, Kira; John, Susan D.; Goske, Marilyn J.; Smith, Susan N.; Charkot, Ellen; Herrmann, Tracy

2011-01-01

Digital radiography (DR) is one of several new products that have changed our work processes from hard copy to digital formats. The transition from analog screen-film radiography to DR requires thorough user education because of differences in image production, processing, storage and evaluation between the forms of radiography. Without adequate education, radiologic technologists could unknowingly expose children to higher radiation doses than necessary for adequate radiograph quality. To evaluate knowledge about image quality and dose management in pediatric DR among radiologic technologists in the U.S. This communication describes a survey of 493 radiologic technologists who are members of the American Society of Radiologic Technologists (ASRT) and who evaluated the current state of radiological technologist education in image quality and dose management in pediatric DR. The survey included 23 survey questions regarding image acquisition issues, quality assurance, radiation exposure and education in DR of infants and children. Radiologic technologists express many needs in areas of training and education in pediatric DR. Suggested improvements include better tools for immediate feedback about image quality and exposure, more information about appropriate technique settings for pediatric patients, more user-friendly vendor manuals and educational materials, more reliable measures of radiation exposure to patients, and more regular and frequent follow-up by equipment vendors. There is a clear and widespread need for comprehensive and practical education in digital image technology for radiologic technologists, especially those engaged in pediatric radiography. The creation of better educational materials and training programs, and the continuation of educational opportunities will require a broad commitment from equipment manufacturers and vendors, educational institutions, pediatric radiology specialty organizations, and individual imaging specialists. (orig.)

Guidelines for anti-scatter grid use in pediatric digital radiography.

Science.gov (United States)

Fritz, Shannon; Jones, A Kyle

2014-03-01

Pediatric radiography presents unique challenges in balancing image quality and patient dose. Removing the anti-scatter grid reduces patient dose but also reduces image contrast. The benefit of using an anti-scatter grid decreases with decreasing patient size. To determine patient thickness thresholds for anti-scatter grid use by comparing scatter-to-primary ratio for progressively thinner patients without a grid to the scatter-to-primary ratio for a standard adult patient with a grid. We used Solid Water™ phantoms ranging in thickness from 7 cm to 16 cm to simulate pediatric abdomens. The scatter-to-primary ratio without a grid was measured for each thickness at 60 kVp, 70 kVp and 80 kVp for X-ray fields of view (FOV) of 378 cm(2), 690 cm(2) and 1,175 cm(2) using indirect digital radiography (iDR) and computed radiography (CR). We determined thresholds for anti-scatter grid use by comparing the intersection of a fit of scatter-to-primary ratio versus patient thickness with a standard adult scatter-to-primary ratio measured for a 23-cm phantom thickness at 80 kVp with an anti-scatter grid. Dose area product (DAP) was also calculated. The scatter-to-primary ratio depended strongly on FOV and weakly on kVp; however DAP increased with decreasing kVp. Threshold thicknesses for grid use varied from 5 cm for a 14 × 17-cm FOV using iDR to 12 cm for an 8 × 10-cm FOV using computed radiography. Removing the anti-scatter grid for small patients reduces patient dose without a substantial increase in scatter-to-primary ratio when the FOV is restricted appropriately. Radiologic technologists should base anti-scatter grid use on patient thickness and FOV rather than age.

Reconstructive dosimetry and radiation doses evaluation of members of the public due to radiological accident in industrial radiography; Dosimetria reconstrutiva e avaliacao de dose de individuos do publico devido a acidente radiologico em radiografia industrial

Energy Technology Data Exchange (ETDEWEB)

Lima, Camila Moreira Araujo de

2016-07-01

Radiological accidents have occurred mainly in the practices recognized as high risk radiological and classified by the IAEA as Categories 1 and 2, and highlighted the radiotherapy, industrial irradiators and industrial radiography. In Brazil, since there were five major cases in industrial radiography, which involved 7 radiation workers and 19 members of the public, causing localized radiation lesions on the hands and fingers. One of these accidents will be the focus of this work. In this accident, a {sup 192}Ir radioactive source was exposed for more than 8 hours in the workplace inside a company, exposing radiation workers, individuals of the public and people from the surrounding facilities, including children of a school. The radioactive source was also handled by a security worker causing severe radiation injuries in the hand and fingers. In this paper, the most relevant and used techniques of reconstructive dosimetry internationally are presented. To estimate the radiation doses received by exposed individuals in various scenarios of radiological accident in focus, the following computer codes were used: Visual Monte Carlo Dose Calculation (VMC), Virtual Environment for Radiological and Nuclear Accidents Simulation (AVSAR) and RADPRO Calculator. Through these codes some radiation doses were estimated, such as, 33.90 Gy in security worker's finger, 4.47 mSv in children in the school and 55 to 160 mSv for workers in the company during the whole day work. It is intended that this work will contribute to the improvement of dose reconstruction methodology for radiological accidents, having then more realist radiation doses. (author)

Implementation of radiation protection programme in industrial radiography centers in Iran

Energy Technology Data Exchange (ETDEWEB)

Deevband, M. [Radiation Protection Department, Tehran (Iran, Islamic Republic of); Ghiassi Negad, M. [Radiation Protection Department, Tehran (Iran, Islamic Republic of); Borhan Azad, S. [Radiation Protection Department, Tehran (Iran, Islamic Republic of); Tavakoli, M. [Esfahan Univ. (Iran, Islamic Republic of)

2006-07-01

Industrial radiography is one of the essential methods in the modern technology to guarantee the quality control of many types of devices, pieces and machines operation, and usually involves intense radiation sources, which can expose people at work to significant amounts of radiation. According to the reports of United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR 2000), the average occupational effective dose in this field is 3.37 mSv/y. The level of dose received by industrial radiographers was assessed in more than 1300 radiation workers in 120 industrial radiography companies. The level of radiation safety regulations and radiation protection programme implemented in Iranian industries was also studied. The results indicated that the average effective dose to the radiographers and collective effective dose are 1.65 mSv/y and 2.43 Man.Sv respectively. The results also showed that 88% of radiographers have received less than 5 mSv/y and only 1% received the annual dose more than 20 mSv. The lack of emergency instruction was found in 47% of companies and in 35% of companies there was not found any compatible emergency instrument. Suitable temporary storage and transportation facility was no also found in 30% of companies. Based on the results found in this study, the enforcement of the radiation protection low and industrial radiography code of practice for responsible persons and health physics officers are recommended. (authors)

Implementation of radiation protection programme in industrial radiography centers in Iran

International Nuclear Information System (INIS)

Deevband, M.; Ghiassi Negad, M.; Borhan Azad, S.; Tavakoli, M.

2006-01-01

Industrial radiography is one of the essential methods in the modern technology to guarantee the quality control of many types of devices, pieces and machines operation, and usually involves intense radiation sources, which can expose people at work to significant amounts of radiation. According to the reports of United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR 2000), the average occupational effective dose in this field is 3.37 mSv/y. The level of dose received by industrial radiographers was assessed in more than 1300 radiation workers in 120 industrial radiography companies. The level of radiation safety regulations and radiation protection programme implemented in Iranian industries was also studied. The results indicated that the average effective dose to the radiographers and collective effective dose are 1.65 mSv/y and 2.43 Man.Sv respectively. The results also showed that 88% of radiographers have received less than 5 mSv/y and only 1% received the annual dose more than 20 mSv. The lack of emergency instruction was found in 47% of companies and in 35% of companies there was not found any compatible emergency instrument. Suitable temporary storage and transportation facility was no also found in 30% of companies. Based on the results found in this study, the enforcement of the radiation protection low and industrial radiography code of practice for responsible persons and health physics officers are recommended. (authors)

Radiography

Science.gov (United States)

Gardner, C. G.

1973-01-01

Radiography is discussed as a method for nondestructive evaluation of internal flaws of solids. Gamma ray and X-ray equipment are described along with radiographic film, radiograph interpretation, and neutron radiography.

Determination, through of thermoluminescence dosimetry, of the incident radiation in critical organs, during cephalometric radiographies

International Nuclear Information System (INIS)

Hipolito Junior, O. di; Goncalves, N.; Boscolo, F.N.; Montebelo Filho, A.

1985-01-01

The object of this paper was to value and to compare the doses of X-ray incident in critical orgas of patient and operator, during cephalometric radiography. Each patient was submited for two radiographics expositions. First of all, they use the followings factors: 85 kVp, 15 mA and 4/10 s of exposition; while of the second radiography the conditions were of 70 kVp, 15 mA and 1.2 s of exposition. The dosimetric method was the thermoluminescent through the LiF-700. Although the cephalometric radiographies showed similars qualities, in bot conditions where the equipment functioned, the situation of high voltage was noted small doses of radiation. (author) [pt

Advances in computed radiography systems and their physical imaging characteristics

International Nuclear Information System (INIS)

Cowen, A.R.; Davies, A.G.; Kengyelics, S.M.

2007-01-01

Radiological imaging is progressing towards an all-digital future, across the spectrum of medical imaging techniques. Computed radiography (CR) has provided a ready pathway from screen film to digital radiography and a convenient entry point to PACS. This review briefly revisits the principles of modern CR systems and their physical imaging characteristics. Wide dynamic range and digital image enhancement are well-established benefits of CR, which lend themselves to improved image presentation and reduced rates of repeat exposures. However, in its original form CR offered limited scope for reducing the radiation dose per radiographic exposure, compared with screen film. Recent innovations in CR, including the use of dual-sided image readout and channelled storage phosphor have eased these concerns. For example, introduction of these technologies has improved detective quantum efficiency (DQE) by approximately 50 and 100%, respectively, compared with standard CR. As a result CR currently affords greater scope for reducing patient dose, and provides a more substantive challenge to the new solid-state, flat-panel, digital radiography detectors

X-ray radiography and tomography applied to material testing

International Nuclear Information System (INIS)

Rechapt, Jean de.

1982-11-01

X-ray radiography and tomography are compared to detect a defect in an object. These image acquisition processes are first modelled by a convolution system. For a fixed contrast defect and a given X ray dose, the process providing the best signal-to-noise ratio is given by calculation. Then a system for pattern recognition is given: for identifying a defect, the related signs from binary images are sorted according to their size. The improvement in the detection performance of the device, for an adapted filtration of the images obtained, is assessed. The whole of the preceding results is validated on images synthesized on a computer, selecting between tomography and radiography, the technique making it possible to ensure the detectability of a defect with a minimal dose of X photons [fr

Gonad protective effect of radiation protective apron in chest radiography

International Nuclear Information System (INIS)

Hashimoto, Masatoshi; Kato, Hideyuki; Fujibuchi, Toshiou; Ochi, Shigehiro; Morita, Fuminori

2004-01-01

Depending on the facility, a radiation protective apron (protector) is used to protect the gonad from radiation exposure in chest radiography. To determine the necessity of using a protector during chest radiography, we measured the effect of the protector on the gonad in this study. First, using a human body phantom, we measured the absorbed dose of the female gonad with and without the protector, using a thermoluminescence dosimeter (TLD), and confirmed its protective effect. Using the protector, the absorbed dose was reduced to 28±2% and 39±4% for field sizes of 14 x 17 inch and 14 x 14 inch, respectively. Next, we used Monte Carlo simulation and confirmed, not only the validity of the actual measurement values, but also the fact that the influence of radiation on the absorbed dose of the gonad was mostly from scattered radiation from inside the body for the 14 x 17 inch field size, and also from the X-ray tube for the 14 x 14 inch field size. Although a certain protective effect is achieved by using the protector, the radiation dose to the gonad is only a few μGy even without a protector. Thus, the risk of a genetic effect would be as small as 10 -8 . Given that acceptable risk is below 10 -6 , we conclude the use of a radiation protective apron is not necessary for diagnostic chest radiography. (author)

[Gonad protective effect of radiation protective apron in chest radiography].

Science.gov (United States)

Hashimoto, Masatoshi; Kato, Hideyuki; Fujibuchi, Toshiou; Ochi, Shigehiro; Morita, Fuminori

2004-12-01

Depending on the facility, a radiation protective apron (protector) is used to protect the gonad from radiation exposure in chest radiography. To determine the necessity of using a protector during chest radiography, we measured the effect of the protector on the gonad in this study. First, using a human body phantom, we measured the absorbed dose of the female gonad with and without the protector, using a thermoluminescence dosimeter (TLD), and confirmed its protective effect. Using the protector, the absorbed dose was reduced to 28+/-2% and 39+/-4% for field sizes of 14 x 17 inch and 14 x 14 inch, respectively. Next, we used Monte Carlo simulation and confirmed, not only the validity of the actual measurement values, but also the fact that the influence of radiation on the absorbed dose of the gonad was mostly from scattered radiation from inside the body for the 14 x 17 inch field size, and also from the X-ray tube for the 14 x 14 inch field size. Although a certain protective effect is achieved by using the protector, the radiation dose to the gonad is only a few microGy even without a protector. Thus, the risk of a genetic effect would be as small as 10(-8). Given that acceptable risk is below 10(-6), we conclude the use of a radiation protective apron is not necessary for diagnostic chest radiography.

Progress in digital radiography

International Nuclear Information System (INIS)

Cappelle, A.

2016-01-01

Because of its practical aspect digital radiography is more and more used in the industrial sector. There are 2 kinds of digital radiography. First, the 'computed radiography' that uses a photon-stimulated screen, and after radiation exposure this screen must be read by an analyser to get a digit image. The second type is the 'direct radiography' that allows one to get a digit radiograph of the object directly. Digital radiography uses the same radioactive nuclides as radiography with silver films: cobalt, iridium or selenium. The spatial resolution of digital radiography is less good than with classical silver film radiography but digital radiography offers a better visual contrast. (A.C.)

Computed tomography scout views vs. conventional radiography in body-packers – Delineation of body-packs and radiation dose in a porcine model

Energy Technology Data Exchange (ETDEWEB)

Ziegeler, Edvard, E-mail: edvard.ziegeler@campus.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany); Grimm, Jochen M., E-mail: jochen.grimm@med.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany); Wirth, Stefan, E-mail: tefan.wirth@med.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany); Uhl, Michael, E-mail: michael.uhl@polizei.bayern.de [Bavarian State Criminal Police Office, Maillingerstrasse 15, 80636 Munich (Germany); Reiser, Maximilian F., E-mail: Maximilian.Reiser@med.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany); Scherr, Michael K., E-mail: Michael.Scherr@med.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany)

2012-12-15

Objective: To compare abdominal computed tomography (CT) scout views with conventional radiography regarding radiation dose and delineation of drug packages in a porcine body-packer model. Materials and methods: Nine samples of illicit drugs packed in ovoid plastic containers were consecutively placed in the rectum of a 121.5 kg pig cadaver. Antero-posterior and lateral scout views were obtained at 120 kVp and 80 mA, 150 mA and 200 mA, respectively, using a 64-row MDCT. Scout views were compared with conventional abdominal antero-posterior radiographs (77 kV and 106 ± 13 mAs). Visibility of three body pack characteristics (wrapping, content, shape) was rated independently by two radiologists and summarized to a delineation score ranging from 0 to 9 with a score ≥6 representing sufficient delineation. Mean delineation scores were calculated for each conventional radiography and single plane scout view separately and for a combined rating of antero-posterior and lateral scout views. Results: Even the lowest single plane scout view delineation score (5.3 ± 2.0 for 80 mA lateral; 0.4 mSv; sensitivity = 44%) was significantly higher than for conventional radiographs (3.1 ± 2.5, p < 0.001; 2.4 ± 0.3 mSv; sensitivity = 11%). Combined reading of antero-posterior and lateral scout views 80 mA yielded sufficient delineation (6.2 ± 1.4; 0.8 mSv; sensitivity = 56%). Conclusions: All CT scout views showed significantly better delineation ratings and sensitivity than conventional radiographs. Scout views in two planes at 80 mA provided a sufficient level of delineation and a sensitivity five times higher than conventional radiography at less than one third of the radiation dose. In case of diagnostic insecurity, CT can be performed without additional logistical effort.

Flash X-Ray Apparatus With Spectrum Control Functions For Medical Use And Fuji Computed Radiography

Science.gov (United States)

Isobe, H.; Sato, E.; Hayasi, Y.; Suzuki, M.; Arima, H.; Hoshino, F.

1985-02-01

Flash radiographic bio-medical studies at sub-microsecond intervals were performed by using both a new type of flash X-ray(FX) apparatus with spectrum control functions and Fuji Computed Radiography(FCR). This single flasher tends to have a comparatively long exposure time and the electric pulse width of the FX wave form is about 0.3,usec. The maximum FX dose is about 50mR at 1m per pulse, and the effective focal spot varies according to condenser charging voltage, A-C distance, etc., ranging from 1.0 to 3.0mm in diameter, but in the low dose rate region it can be reduced to less than 1.0mm in diameter. The FX dose is determined by the condenser charging voltage and the A-C distance, while the FX spectrum is determined by the average voltage of the FX tube and filters. Various clear FX images were obtained by controlling the spectrum and dose. FCR is a new storage medium for medical radiography developed by the Fuji Photo Film Co., Ltd. and this apparatus has various image forming functions: low dose radiography, film density control, image contrast control, subtraction management and others. We have used this new apparatus in conjunction with our FX radiography and have obtained some new and interesting biomedical radiograms: the edge enhancement image, the instantaneous enlarged image, and the single exposure energy subtraction image using the FX spectrum distribution.

Assessing the dose values received by patients during conventional radiography X-ray examinations and the technical condition of the equipment used for this purpose.

Science.gov (United States)

Bekas, Marcin; Pachocki, Krzysztof A; Waśniewska, Elżbieta; Bogucka, Dagmara; Magiera, Andrzej

2014-01-01

X-ray examination is associated with patient exposure to ionizing radiation. Dose values depend on the type of medical procedure used, the X-ray unit technical condition and exposure conditions selected. The aim of this study was to determine the dose value received by patients during certain conventional radiography X-ray examinations and to assess the technical condition of medical equipment used for this purpose. The study covered the total number of 118 conventional diagnostic X-ray units located in the Masovian Voivodeship. The methodology used to assess the conventional diagnostic X-ray unit technical condition and the measurement of the radiation dose rate received by patients are based on test procedures developed by the Department of Radiation Protection and Radiobiology of the National Institute of Public Health - National Institute of Hygiene (Warszawa, Poland) accredited for compliance with PN-EN 17025 standard by the Polish Centre for Accreditation. It was found that 84.7% of X-ray units fully meet the criteria set out in the Polish legislation regarding the safe use of ionizing radiation in medicine, while 15.3% of the units do not meet some of them. The broadest dose value range was recorded for adult patients. Particularly, during lateral (LATl) lumbar spine radiography the recorded entrance surface dose (ESD) values ranged from 283.5 to 7827 µGy (mean: 2183.3 µGy). It is absolutely necessary to constantly monitor the technical condition of all X-ray units, because it affects population exposure to ionizing radiation. Furthermore, it is essential to raise radiographers' awareness of the effects that ionizing radiation exposure can have on the human body.

WE-EF-303-04: An Advanced Image Processing Method to Improve the Spatial Resolution of Proton Radiographies

International Nuclear Information System (INIS)

Rinaldi, I; Parodi, K; Krah, N

2015-01-01

Purpose: We present an optimization method to improve the spatial resolution and the water equivalent thickness accuracy of proton radiographies. Methods: The method is designed for imaging systems measuring only the residual range of protons without relying on tracker detectors to determine the beam trajectory before and after the target. Specifically, the method was used for an imaging set-up consisting of a stack of 61 parallel-plate ionization chambers (PPIC) working as a range telescope. The method uses a decomposition approach of the residual range signal measured by the PPIC and constructs subimages with small size pixels geometrically rearranged and appropriately averaged to be merged into a final single radiography. The method was tested using Monte Carlo simulated and experimental proton radiographies of a PMMA step phantom and an anthropomorphic head phantom. Results: For the step phantom, the effective spatial resolution was found to be 4 and 3 times higher than the nominal resolution for the simulated and experimental radiographies, respectively. For the head phantom, a gamma index was calculated to quantify the conformity of the simulated proton radiographies with a digitally reconstructed X-ray radiography convolved with a Gaussian kernel equal to the proton beam spot-size. For DTA=2.5 mm and RD=2.5%, the passing ratio was 100%/85% for the optimized/non-optimized case, respectively. An extension of the method allows reducing the dose given to the patient during radiography acquisition. We show that despite a dose reduction of 25 times (leading to a dose of 0.016 mGy for the current imaging set-up), the image quality of the optimized radiographies remains fairly unaffected for both the simulated and experimental results. Conclusion: The optimization method leads to a significant increase of the spatial resolution allowing recovering image details that are unresolved in non-optimized radiographies. These results represent a major step towards clinical

Fine tuning of work practices of common radiological investigations performed using computed radiography system

International Nuclear Information System (INIS)

Livingstone, Roshan S.; Timothy Peace, B.S.; Sunny, S.; Victor Raj, D.

2007-01-01

Introduction: The advent of the computed radiography (CR) has brought about remarkable changes in the field of diagnostic radiology. A relatively large cross-section of the human population is exposed to ionizing radiation on account of common radiological investigations. This study is intended to audit radiation doses imparted to patients during common radiological investigations involving the use of CR systems. Method: The entrance surface doses (ESD) were measured using thermoluminescent dosimeters (TLD) for various radiological investigations performed using the computed radiography (CR) systems. Optimization of radiographic techniques and radiation doses was done by fine tuning the work practices. Results and conclusion: Reduction of radiation doses as high as 47% was achieved during certain investigations with the use of optimized exposure factors and fine-tuned work practices

Evaluation of a low-dose neonatal chest radiographic system

International Nuclear Information System (INIS)

Burton, E.M.; Kirks, D.R.; Strife, J.L.; Henry, G.C.; Kereiakes, J.G.

1988-01-01

A new low-dose chest radiographic system for use in the neonatal nursery was evaluated. This test system, composed of a Du Pont Kevlar fiber-front cassette, Quanta fast-detail screen, Cronex 4L film (wide latitude), and additional yttrium filtration (0.1 mm), reduced the radiation dose in neonatal chest radiography by 69% (0.9 vs 2.9 mrad [0.009 vs 0.029 mGy]) as compared with a conventional system without added yttrium filtration; the thyroid dose was reduced by 76% (0.9 vs 3.7 mrad [0.009 vs 0.037 mGy]). The cumulative dose reduction was achieved through a combination of factors, including (1) beam hardening by the added yttrium filter, (2) increased X-ray transmission through the Kevlar cassette, and (3) a fast film-screen combination. Scatter radiation at distances of 1 and 6 ft. (0.3 and 1.8 m) was negligible for both systems. Image sharpness was compared for the conventional system with and without added yttrium filtration and for the Kevlar system with yttrium. Although sharpness of bony detail was unchanged by adding yttrium filtration to the conventional system, a decrease in sharpness was noted with the Kevlar system. Because image sharpness was affected in the test system, we are not using the Kevlar-Cronex 4L system for mobile chest radiography in the neonatal intensive care unit, despite dose reductions. However, further study is recommended to determine if there is a slower film-screen combination with yttrium filtration that will not degrade image sharpness

Annual dose equivalents estimation received by Cienfuegos population due medical practice

International Nuclear Information System (INIS)

Usagaua R, Z.; Santander I, E.

1996-01-01

This study represents the first evaluation of the effective equivalent dose that receives the population of the Cienfuegos province in Cuba because of medical practice. The evaluation is based on the tables of doses depending on several parameters that influence over these ones, and also based on large diagnostic examinations statistics of all medical institutions over a 9 years period. Values of examinations frequency, contribution to total dose from radiography, fluoroscopy, dental radiography and nuclear medicine, and other characteristics of the last ones are offered. A comparative reflection dealing with received doses by radiography and fluoroscopy techniques is also included. (authors). 4 refs

Radiation exposures of workers resulting from the transport of gamma radiography sources in Germany

International Nuclear Information System (INIS)

Sentuc, F.N.; Schwarz, G.

2006-01-01

Gamma radiation sources are widely used for industrial purposes e.g. for non-destructive material testing. Many of these sources are permanently installed at a facility within instruments e.g. for level or thickness gauging. Other radioactive sources are implemented in portable devices for industrial gamma radiography which have to be carried to the various remote usage sites. In Germany, approximately 20 000 - 25 000 shipments of gamma radiography sources are proceeding annually on public transport routes. Since routine radiation monitoring programmes do not permit task-specific determination of occupational doses e.g. doses incurred during the movement phase and handling related doses, work has been carried out with the objective to determine the radiation exposures of the personnel attributable to transportation. For this purpose, a survey was launched in 2005 collecting data about e.g. the number and conditions of transports, the activity and type of transported radiation sources and the radiation level within the driver's cab to allow a dose assessment to be made for transport workers. The results of this survey covering the most important companies for gamma radiography services in Germany are presented in this paper. (authors)

Digital radiography

International Nuclear Information System (INIS)

Zani, M.L.

2002-01-01

X-ray radiography is a very common technique used to check the homogeneity of a material or the inside of a mechanical part. Generally the radiation that goes through the material to check, produced an image on a sensitized film. This method requires time because the film needs to be developed, digital radiography has no longer this inconvenient. In digital radiography the film is replaced by digital data and can be processed as any computer file. This new technique is promising but its main inconvenient is that today its resolution is not so good as that of film radiography. (A.C.)

Anthropomorphic chest phantom imaging – The potential for dose creep in computed radiography

International Nuclear Information System (INIS)

Ma, W.K.; Hogg, P.; Tootell, A.; Manning, D.; Thomas, N.; Kane, T.; Kelly, J.; McKenzie, M.; Kitching, J.

2013-01-01

For film-based radiography the operator had to be exact in the selection of acquisition parameters or the image could easily become under- or over-exposed. By contrast, digital technology allows for a much greater tolerance of acquisition factor selection which would still give an image of acceptable diagnostic quality. In turn this greater tolerance allows for the operator to increase effective dose for little or no penalty in image quality. The purpose of this article is to determine how image quality and lesion visibility vary with effective dose (E) in order to identify how much overexposure could be tolerated within the radiograph. Using an anthropomorphic chest phantom with ground glass lesions we determined how perceptual image quality and E varied over a wide range of acquisition conditions. Perceptual image quality comprised of image quality and lesion visibility. E was calculated using Monte Carlo method; image quality was determined using a two alternative forced choice (2AFC) method and the quality criteria were partly informed from European guidelines. Five clinicians with significant experience in image reading scored the images for quality (intraclass correlation coefficient 0.869). Image quality and lesion visibility had a close correlation (R 2 > 0.8). The tolerance for over-exposure, whilst still acquiring an image of acceptable quality, increases with decreasing kV and increasing source to image distance (SID). The maximum over-exposure factor (ratio of maximum E to minimum E that produce images of acceptable quality) possible was 139 (at 125 cm and 60 kV). Given the phantom had characteristics similar to the human thorax we propose that that potential for overexposure in a human whilst still obtaining an image of acceptable perceptual image quality is very high. Further research into overexposure tolerance and dose creep should be undertaken

Megavoltage cargo radiography with dual energy material decomposition

Science.gov (United States)

Shikhaliev, Polad M.

2018-02-01

Megavoltage (MV) radiography has important applications in imaging large cargos for detecting illicit materials. A useful feature of MV radiography is the possibility of decomposing and quantifying materials with different atomic numbers. This can be achieved by imaging cargo at two different X-ray energies, or dual energy (DE) radiography. The performance of both single energy and DE radiography depends on beam energy, beam filtration, radiation dose, object size, and object content. The purpose of this work was to perform comprehensive qualitative and quantitative investigations of the image quality in MV radiography depending on the above parameters. A digital phantom was designed including Fe background with thicknesses of 2cm, 6cm, and 18cm, and materials samples of Polyethylene, Fe, Pb, and U. The single energy images were generated at x-ray beam energies 3.5MV, 6MV, and 9MV. The DE material decomposed images were generated using interlaced low and high energy beams 3.5/6MV and 6/9MV. The X-ray beams were filtered by low-Z (Polyethylene) and high-Z (Pb) filters with variable thicknesses. The radiation output of the accelerator was kept constant for all beam energies. The image quality metrics was signal-to-noise ratio (SNR) of the particular sample over a particular background. It was found that the SNR depends on the above parameters in a complex way, but can be optimized by selecting a particular set of parameters. For some imaging setups increased filter thicknesses, while strongly absorbing the beams, increased the SNR of material decomposed images. Beam hardening due to polyenergetic x-ray spectra resulted in material decomposition errors, but this could be addressed using region of interest decomposition. It was shown that it is not feasible to separate the materials with close atomic numbers using the DE method. Particularly, Pb and U were difficult to decompose, at least at the dose levels allowed by radiation source and safety requirements.

Analysis of causes of radiation overexposures for radiation workers in industrial radiography

International Nuclear Information System (INIS)

Mahajan, J.M.; Massand, O.P.

2001-01-01

About 5500 radiation workers are monitored from industrial institutions in our country out of which 3600 radiation workers are working in industrial radiography institutions. These workers have a higher potential of receiving overexposure (equivalent dose 3 10 mSv) due to their nature of work. This paper presents analysis of overexposures and their causes for radiation workers working in industrial radiography institutions during the last seven years. (author)

Initial results from a multiple monoenergetic gamma radiography system for nuclear security

Science.gov (United States)

O'Day, Buckley E.; Hartwig, Zachary S.; Lanza, Richard C.; Danagoulian, Areg

2016-10-01

The detection of assembled nuclear devices and concealed special nuclear materials (SNM) such as plutonium or uranium in commercial cargo traffic is a major challenge in mitigating the threat of nuclear terrorism. Currently available radiographic and active interrogation systems use ∼1-10 MeV bremsstrahlung photon beams. Although simple to build and operate, bremsstrahlung-based systems deliver high radiation doses to the cargo and to potential stowaways. To eliminate problematic issues of high dose, we are developing a novel technique known as multiple monoenergetic gamma radiography (MMGR). MMGR uses ion-induced nuclear reactions to produce two monoenergetic gammas for dual-energy radiography. This allows us to image the areal density and effective atomic number (Zeff) of scanned cargo. We present initial results from the proof-of-concept experiment, which was conducted at the MIT Bates Research and Engineering Center. The purpose of the experiment was to assess the capabilities of MMGR to measure areal density and Zeff of container cargo mockups. The experiment used a 3.0 MeV radiofrequency quadrupole accelerator to create sources of 4.44 MeV and 15.11 MeV gammas from the 11B(d,nγ)12C reaction in a thick natural boron target; the gammas are detected by an array of NaI(Tl) detectors after transmission through cargo mockups . The measured fluxes of transmitted 4.44 MeV and 15.11 MeV gammas were used to assess the areal density and Zeff. Initial results show that MMGR is capable of discriminating the presence of high-Z materials concealed in up to 30 cm of iron shielding from low- and mid-Z materials present in the cargo mockup.

Evidence-based radiography

International Nuclear Information System (INIS)

Hafslund, Bjorg; Clare, Judith; Graverholt, Birgitte; Wammen Nortvedt, Monica

2008-01-01

Evidence-based practice (EBP) offers the integration of the best research evidence with clinical knowledge and expertise and patient values. EBP is a well known term in health care. This paper discusses the implementation of EBP into radiography and introduces the term evidence-based radiography. Evidence-based radiography is radiography informed and based on the combination of clinical expertise and the best available research-based evidence, patient preferences and resources available. In Norway, EBP in radiography is being debated and radiographers are discussing the challenges of implementing EBP in both academic and clinical practice. This discussion paper explains why EBP needs to be a basis for a radiography curriculum and a part of radiographers' practice. We argue that Norwegian radiographers must increase participation in research and developing practice within their specific radiographic domain

Estimation of radiation dose received by the radiation workers during radiographic testing

International Nuclear Information System (INIS)

Mohammed, N. A. H. O.

2013-08-01

This study was conducted primarily to evaluate occupational radiation dose in industrial radiography during radiographic testing at Balil-Hadida, with the aim of building up baseline data on radiation exposure in the industrial radiography practice in Sudan. Dose measurements during radiographic testing were performed and compared with IAEA reference dose. In this research the doses measured by using hand held radiation survey meter and personal monitoring dosimeter. The results showed that radiation doses ranged between minimum (0.448 mSv/ 3 month) , and maximum (1.838 mSv / 3 month), with an average value (0.778 mSv/ 3 month), and the standard deviation 0.292 for the workers used gamma mat camera. The analysis of data showed that the radiation dose for all radiation worker are receives less than annual limit for exposed workers 20 mSv/ year and compare with other study found that the dose received while body doses ranging from 0.1 to 9.4 mSv/ year, work area design in all the radiography site followed the three standard rules namely putting radiation signs, reducing access to control area and making of boundaries. Thus the accidents arising from design faults not likely to occur at these site. Results suggest that adequate fundamental training of radiation workers in general radiography prior to industrial radiography work will further improve the standard of personnel radiation protection. (Author)

Optimization of selective exposure radiography of the chest

International Nuclear Information System (INIS)

Naimuddin, S.

1986-01-01

A major technical limitation in conventional chest radiography is the mismatch of the x-ray transmission dynamic range with the useful exposure range of a radiographic film when a patient is presented with a uniform incident exposure field. The goal of this project is to develop a faster and more reliable selective exposure system to fabricate and position a compensating filter (or digital beam attenuator, DBA) for clinical use. The essential components of this system include a dose efficient test-image detector, a special purpose field grabber (image memory), a custom made fast printer, a transport channel, and a computer. The fabrication process begins with acquisition of a 64 x 64 format low-dose patient image which undergoes corrections for detector nonuniformity and scatter. The corrected data after log transformation are used to calculate thickness of filter material needed to compensate for the image dynamic range. Using this thickness information the computer controls the printer which fabricates as attenuator by overprinting multiple layers of cerium oxide on a 35 mm film substrate. Although the images are acquired in a 64 x 64 format, the attenuator is constructed in a dithered 16 x 16 format using a special algorithm. After fabrication, the attenuator is automatically conveyed through the transport channel and is positioned in the x-ray beam between the collimator and x-ray tube before the final compensated radiograph is taken

Dose ratio proton radiography using the proximal side of the Bragg peak

Energy Technology Data Exchange (ETDEWEB)

Doolan, P. J., E-mail: paul.doolan.09@ucl.ac.uk; Royle, G.; Gibson, A. [Department of Medical Physics and Bioengineering, University College London, London WC1E 6BT (United Kingdom); Lu, H.-M. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts 02114 (United States); Prieels, D.; Bentefour, E. H. [Ion Beam Applications (IBA), 3 Chemin du Cyclotron, Louvain la Neuve B-1348 (Belgium)

2015-04-15

Purpose: In recent years, there has been a movement toward single-detector proton radiography, due to its potential ease of implementation within the clinical environment. One such single-detector technique is the dose ratio method in which the dose maps from two pristine Bragg peaks are recorded beyond the patient. To date, this has only been investigated on the distal side of the lower energy Bragg peak, due to the sharp falloff. The authors investigate the limits and applicability of the dose ratio method on the proximal side of the lower energy Bragg peak, which has the potential to allow a much wider range of water-equivalent thicknesses (WET) to be imaged. Comparisons are made with the use of the distal side of the Bragg peak. Methods: Using the analytical approximation for the Bragg peak, the authors generated theoretical dose ratio curves for a range of energy pairs, and then determined how an uncertainty in the dose ratio would translate to a spread in the WET estimate. By defining this spread as the accuracy one could achieve in the WET estimate, the authors were able to generate lookup graphs of the range on the proximal side of the Bragg peak that one could reliably use. These were dependent on the energy pair, noise level in the dose ratio image and the required accuracy in the WET. Using these lookup graphs, the authors investigated the applicability of the technique for a range of patient treatment sites. The authors validated the theoretical approach with experimental measurements using a complementary metal oxide semiconductor active pixel sensor (CMOS APS), by imaging a small sapphire sphere in a high energy proton beam. Results: Provided the noise level in the dose ratio image was 1% or less, a larger spread of WETs could be imaged using the proximal side of the Bragg peak (max 5.31 cm) compared to the distal side (max 2.42 cm). In simulation, it was found that, for a pediatric brain, it is possible to use the technique to image a region with a

Small-animal dark-field radiography for pulmonary emphysema evaluation

Science.gov (United States)

Yaroshenko, Andre; Meinel, Felix G.; Hellbach, Katharina; Bech, Martin; Velroyen, Astrid; Müller, Mark; Bamberg, Fabian; Nikolaou, Konstantin; Reiser, Maximilian F.; Yildirim, Ali Ã.-.; Eickelberg, Oliver; Pfeiffer, Franz

2014-03-01

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of morbidity and mortality worldwide and emphysema is one of its main components. The disorder is characterized by irreversible destruction of the alveolar walls and enlargement of distal airspaces. Despite the severe changes in the lung tissue morphology, conventional chest radiographs have only a limited sensitivity for the detection of mild to moderate emphysema. X-ray dark-field is an imaging modality that can significantly increase the visibility of lung tissue on radiographic images. The dark-field signal is generated by coherent, small-angle scattering of x-rays on the air-tissue interfaces in the lung. Therefore, morphological changes in the lung can be clearly visualized on dark-field images. This is demonstrated by a preclinical study with a small-animal emphysema model. To generate a murine model of pulmonary emphysema, a female C57BL/6N mouse was treated with a single orotracheal application of porcine pancreatic elastase (80 U/kg body weight) dissolved in phosphate-buffered saline (PBS). Control mouse received PBS. The mice were imaged using a small-animal dark-field scanner. While conventional x-ray transmission radiography images revealed only subtle indirect signs of the pulmonary disorder, the difference between healthy and emphysematous lungs could be clearly directly visualized on the dark-field images. The dose applied to the animals is compatible with longitudinal studies. The imaging results correlate well with histology. The results of this study reveal the high potential of dark-field radiography for clinical lung imaging.

In Vivo Dark-Field Radiography for Early Diagnosis and Staging of Pulmonary Emphysema.

Science.gov (United States)

Hellbach, Katharina; Yaroshenko, Andre; Meinel, Felix G; Yildirim, Ali Ö; Conlon, Thomas M; Bech, Martin; Mueller, Mark; Velroyen, Astrid; Notohamiprodjo, Mike; Bamberg, Fabian; Auweter, Sigrid; Reiser, Maximilian; Eickelberg, Oliver; Pfeiffer, Franz

2015-07-01

The aim of this study was to evaluate the suitability of in vivo x-ray dark-field radiography for early-stage diagnosis of pulmonary emphysema in mice. Furthermore, we aimed to analyze how the dark-field signal correlates with morphological changes of lung architecture at distinct stages of emphysema. Female 8- to 10-week-old C57Bl/6N mice were used throughout all experiments. Pulmonary emphysema was induced by orotracheal injection of porcine pancreatic elastase (80-U/kg body weight) (n = 30). Control mice (n = 11) received orotracheal injection of phosphate-buffered saline. To monitor the temporal patterns of emphysema development over time, the mice were imaged 7, 14, or 21 days after the application of elastase or phosphate-buffered saline. X-ray transmission and dark-field images were acquired with a prototype grating-based small-animal scanner. In vivo pulmonary function tests were performed before killing the animals. In addition, lungs were obtained for detailed histopathological analysis, including mean cord length (MCL) quantification as a parameter for the assessment of emphysema. Three blinded readers, all of them experienced radiologists and familiar with dark-field imaging, were asked to grade the severity of emphysema for both dark-field and transmission images. Histopathology and MCL quantification confirmed the introduction of different stages of emphysema, which could be clearly visualized and differentiated on the dark-field radiograms, whereas early stages were not detected on transmission images. The correlation between MCL and dark-field signal intensities (r = 0.85) was significantly higher than the correlation between MCL and transmission signal intensities (r = 0.37). The readers' visual ratings for dark-field images correlated significantly better with MCL (r = 0.85) than visual ratings for transmission images (r = 0.36). Interreader agreement and the diagnostic accuracy of both quantitative and visual assessment were significantly higher

Basic research of neutron radiography using cold neutron beam

International Nuclear Information System (INIS)

Oda, Masahiro; Tamaki, Masayoshi; Tasaka, Kanji

1995-01-01

As the result of demanding high quality images, now the nuclear reactors which can supply stably intense neutron beam have become the most general neutron source for radiography. For the purpose, mostly thermal neutrons have been used, but it is indispensable to use other neutrons than thermal neutrons for advancing neutron radiography technology and expanding the application fields. The radiography using cold neutrons is most behind in the development because the suitable neutron source was not available in Japan. The neutron sources for exclusively obtaining intense cold neutron beam were installed in the Kyoto University reactor in 1986 and in the JRR-3M of Japan Atomic Energy Research Institute in 1991. Basically as neutron energy lowers, the cross section of substances increases. In certain crystalline substances, the Bragg cutoff arises. The removal of scattered neutrons, the measurement of parallelism of beam and the relation of the thickness of objects with the transmissivity of cold neutrons are described. The imaging by TV method and the cold neutron CT in the CNRF and the simplified neutron CT by film method are reported. (K.I.)

Estimation of the collective effective dose to the population from medical X-ray examinations in Finland

International Nuclear Information System (INIS)

Tenkanen-Rautakoskia, Petra; Jaervinen, Hannu; Bly, Ritva

2008-01-01

The collective effective dose to the population from all X-ray examinations in Finland in 2005 was estimated. The numbers of X-ray examinations were collected by a questionnaire to the health care units (response rate 100 %). The effective doses in plain radiography were calculated using a Monte Carlo based program (PCXMC), as average values for selected health care units. For computed tomography (CT), weighted dose length product (DLP w ) in a standard phantom was measured for routine CT protocols of four body regions, for 80 % of CT scanners including all types. The effective doses were calculated from DPL w values using published conversion factors. For contrast-enhanced radiology and interventional radiology, the effective dose was estimated mainly by using published DAP values and conversion factors for given body regions. About 733 examinations per 1000 inhabitants (excluding dental) were made in 2005, slightly less than in 2000. The proportions of plain radiography, computed tomography, contrast-enhanced radiography and interventional procedures were about 92, 7, 1 and 1 %, respectively. From 2000, the frequencies (number of examinations per 1000 inhabitants) of plain radiography and contrast-enhanced radiography have decreased about 8 and 33 %, respectively, while the frequencies of CT and interventional radiology have increased about 28 and 38 %, respectively. The population dose from all X-ray examinations is about 0.43 mSv per person (in 1997 0.5 mSv). About half of this is caused by CT (in 1997 only 20 %) although the relative number of CT examinations is only 7 %. The contribution by plain radiography is 19 %, interventional radiology 17 %, and contrast-enhanced radiology 14 %. It is concluded that CT examinations are the major source of the population dose, while interventional radiology gives about the same population dose as plain radiography. For plain radiography, body examinations cause the highest effective dose. (author)

Heavy-ion radiography and heavy-ion computed tomography

International Nuclear Information System (INIS)

Fabrikant, J.I.; Holley, W.R.; McFarland, E.W.; Tobias, C.a.

1982-02-01

Heavy-ion projection and CT radiography is being developed into a safe, low-dose, noninvasive radiological procedure that can quantitate and image small density differences in human tissues. The applications to heavy-ion mammography and heavy-ion CT imaging of the brain in clinical patients suggest their potential value in cancer diagnosis

Radiography with cosmic-ray and compact accelerator muons; Exploring inner-structure of large-scale objects and landforms.

Science.gov (United States)

Nagamine, Kanetada

2016-01-01

Cosmic-ray muons (CRM) arriving from the sky on the surface of the earth are now known to be used as radiography purposes to explore the inner-structure of large-scale objects and landforms, ranging in thickness from meter to kilometers scale, such as volcanic mountains, blast furnaces, nuclear reactors etc. At the same time, by using muons produced by compact accelerators (CAM), advanced radiography can be realized for objects with a thickness in the sub-millimeter to meter range, with additional exploration capability such as element identification and bio-chemical analysis. In the present report, principles, methods and specific research examples of CRM transmission radiography are summarized after which, principles, methods and perspective views of the future CAM radiography are described.

Characterization of the Annular Core Research Reactor (ACRR Neutron Radiography System Imaging Plane

Directory of Open Access Journals (Sweden)

Kaiser Krista

2016-01-01

Full Text Available The Annular Core Research Reactor (ACRR at Sandia National Laboratories (SNL is an epithermal pool-type research reactor licensed up to a thermal power of 2.4 MW. The ACRR facility has a neutron radiography facility that is used for imaging a wide range of items including reactor fuel and neutron generators. The ACRR neutron radiography system has four apertures (65:1, 125:1, 250:1, and 500:1 available to experimenters. The neutron flux and spectrum as well as the gamma dose rate were characterized at the imaging plane for the ACRR's neutron radiography system for the 65:1, 125:1 and 250:1 apertures.

Low-dose biplanar radiography can be used in children and adolescents to accurately assess femoral and tibial torsion and greatly reduce irradiation

Energy Technology Data Exchange (ETDEWEB)

Meyrignac, Olivier; Baunin, Christiane; Vial, Julie; Sans, Nicolas [CHU Toulouse Purpan, Department of Radiology, Toulouse Cedex 9 (France); Moreno, Ramiro [ALARA Expertise, Oberhausbergen (France); Accadbled, Franck; Gauzy, Jerome Sales de [Hopital des Enfants, Department of Orthopedics, Toulouse Cedex 9 (France); Sommet, Agnes [Universite Paul Sabatier, Department of Fundamental Pharmaco-Clinical Pharmacology, Toulouse (France)

2015-06-01

To evaluate in children the agreement between femoral and tibial torsion measurements obtained with low-dose biplanar radiography (LDBR) and CT, and to study dose reduction ratio between these two techniques both in vitro and in vivo. Thirty children with lower limb torsion abnormalities were included in a prospective study. Biplanar radiographs and CTs were performed for measurements of lower limb torsion on each patient. Values were compared using Bland-Altman plots. Interreader and intrareader agreements were evaluated by intraclass correlation coefficients. Comparative dosimetric study was performed using an ionization chamber in a tissue-equivalent phantom, and with thermoluminescent dosimeters in 5 patients. Average differences between CT and LDBR measurements were -0.1 ±1.1 for femoral torsion and -0.7 ±1.4 for tibial torsion. Interreader agreement for LDBR measurements was very good for both femoral torsion (FT) (0.81) and tibial torsion (TT) (0.87). Intrareader agreement was excellent for FT (0.97) and TT (0.89). The ratio between CT scan dose and LDBR dose was 22 in vitro (absorbed dose) and 32 in vivo (skin dose). Lower limb torsion measurements obtained with LDBR are comparable to CT measurements in children and adolescents, with a considerably reduced radiation dose. (orig.)

Real-time scatter measurement and correction in film radiography

International Nuclear Information System (INIS)

Shaw, C.G.

1987-01-01

A technique for real-time scatter measurement and correction in scanning film radiography is described. With this technique, collimated x-ray fan beams are used to partially reject scattered radiation. Photodiodes are attached to the aft-collimator for sampled scatter measurement. Such measurement allows the scatter distribution to be reconstructed and subtracted from digitized film image data for accurate transmission measurement. In this presentation the authors discuss the physical and technical considerations of this scatter correction technique. Examples are shown that demonstrate the feasibility of the technique. Improved x-ray transmission measurement and dual-energy subtraction imaging are demonstrated with phantoms

Lung nodule detection by microdose CT versus chest radiography (standard and dual-energy subtracted).

Science.gov (United States)

Ebner, Lukas; Bütikofer, Yanik; Ott, Daniel; Huber, Adrian; Landau, Julia; Roos, Justus E; Heverhagen, Johannes T; Christe, Andreas

2015-04-01

The purpose of this study was to investigate the feasibility of microdose CT using a comparable dose as for conventional chest radiographs in two planes including dual-energy subtraction for lung nodule assessment. We investigated 65 chest phantoms with 141 lung nodules, using an anthropomorphic chest phantom with artificial lung nodules. Microdose CT parameters were 80 kV and 6 mAs, with pitch of 2.2. Iterative reconstruction algorithms and an integrated circuit detector system (Stellar, Siemens Healthcare) were applied for maximum dose reduction. Maximum intensity projections (MIPs) were reconstructed. Chest radiographs were acquired in two projections with bone suppression. Four blinded radiologists interpreted the images in random order. A soft-tissue CT kernel (I30f) delivered better sensitivities in a pilot study than a hard kernel (I70f), with respective mean (SD) sensitivities of 91.1%±2.2% versus 85.6%±5.6% (p=0.041). Nodule size was measured accurately for all kernels. Mean clustered nodule sensitivity with chest radiography was 45.7%±8.1% (with bone suppression, 46.1%±8%; p=0.94); for microdose CT, nodule sensitivity was 83.6%±9% without MIP (with additional MIP, 92.5%±6%; pmicrodose CT for readers 1, 2, 3, and 4 were 84.3%, 90.7%, 68.6%, and 45.0%, respectively. Sensitivities with chest radiography for readers 1, 2, 3, and 4 were 42.9%, 58.6%, 36.4%, and 90.7%, respectively. In the per-phantom analysis, respective sensitivities of microdose CT versus chest radiography were 96.2% and 75% (pmicrodose CT, the applied dose was 0.1323 mSv. Microdose CT is better than the combination of chest radiography and dual-energy subtraction for the detection of solid nodules between 5 and 12 mm at a lower dose level of 0.13 mSv. Soft-tissue kernels allow better sensitivities. These preliminary results indicate that microdose CT has the potential to replace conventional chest radiography for lung nodule detection.

Digital luminescent radiography: A substitute for conventional chest radiography?

International Nuclear Information System (INIS)

Neufang, K.F.R.; Krug, B.; Lorenz, R.; Steinbrich, W.

1990-01-01

The image quality of digital luminescent radiography (DLR) is sufficient for routine biplane chest radiography and for follow-up studies of heart size, pulmonary congestion, coin lesions, infiltrations, atelectasis, pleural effusions, and mediastinal and hilar lymph node enlargement. Chest radiography in the intensive care unit may in most cases be performed using the DLR technique. there is no need for repeat shots because of incorrect exposure, and the position of catheters, tubes, pacemakers, drains and artificial heart valves, the mediastinum, and the retrocardiac areas of the left lung are more confidently assessed on the edge-enhanced DLR films than on conventional films. Nevertheless, DLR is somewhat inferior to conventional film-screen radiography of the chest as it can demonstrate or rule out subtle pulmonary interstitial disease less confidently. There is no reduction of radiation exposure of the chest in DLR compared with modern film-screen systems. As a consequence, DLR is presently not in a position to replace traditional film-screen radiography of the chest completely. (orig.) [de

Solid-state, flat-panel, digital radiography detectors and their physical imaging characteristics

Energy Technology Data Exchange (ETDEWEB)

Cowen, A.R. [LXi Research, Academic Unit of Medical Physics, University of Leeds, West Yorkshire (United Kingdom)], E-mail: a.r.cowen@leeds.ac.uk; Kengyelics, S.M.; Davies, A.G. [LXi Research, Academic Unit of Medical Physics, University of Leeds, West Yorkshire (United Kingdom)

2008-05-15

Solid-state, digital radiography (DR) detectors, designed specifically for standard projection radiography, emerged just before the turn of the millennium. This new generation of digital image detector comprises a thin layer of x-ray absorptive material combined with an electronic active matrix array fabricated in a thin film of hydrogenated amorphous silicon (a-Si:H). DR detectors can offer both efficient (low-dose) x-ray image acquisition plus on-line readout of the latent image as electronic data. To date, solid-state, flat-panel, DR detectors have come in two principal designs, the indirect-conversion (x-ray scintillator-based) and the direct-conversion (x-ray photoconductor-based) types. This review describes the underlying principles and enabling technologies exploited by these designs of detector, and evaluates their physical imaging characteristics, comparing performance both against each other and computed radiography (CR). In standard projection radiography indirect conversion DR detectors currently offer superior physical image quality and dose efficiency compared with direct conversion DR and modern point-scan CR. These conclusions have been confirmed in the findings of clinical evaluations of DR detectors. Future trends in solid-state DR detector technologies are also briefly considered. Salient innovations include WiFi-enabled, portable DR detectors, improvements in x-ray absorber layers and developments in alternative electronic media to a-Si:H.

Patient risk from interproximal radiography

International Nuclear Information System (INIS)

Gibbs, S.J.; Pujol, A. Jr.; Chen, T.S.; Malcolm, A.W.; James, A.E. Jr.

1984-01-01

Computer simulation methods for determining patient dose from dental radiography have demonstrated that patient risk from a two-film interproximal examination ranges from 1.1 X 10(-8) to 3.4 X 10(-7) using 90-kVp beams, depending on film speed, projection technique, and age and sex of the patient. Further, changing from a short-cone round-beam to a long-cone technique with rectangular collimation reduces risk by a factor of 2.9, independent of other factors

Quality assurance of computed and digital radiography systems

International Nuclear Information System (INIS)

Walsh, C.; Gorman, D.; Byrne, P.; Larkin, A.; Dowling, A.; Malone, J. F.

2008-01-01

Computed radiography (CR) and digital radiography (DR) are replacing traditional film screen radiography as hospitals move towards digital imaging and picture archiving and communication systems (PACS). Both IPEM and KCARE have recently published quality assurance and acceptance testing guidelines for DR. In this paper, the performance of a range of CR and DR systems is compared. Six different manufacturers are included. Particular attention is paid to the performance of the systems under automatic exposure control (AEC). The patient is simulated using a range of thicknesses of tissue equivalent material. Image quality assessment was based on detector assessment protocols and includes pixel value measures as well as subjective assessment using Leeds Test Objects. The protocols for detector assessment cover a broad range of tests and in general detectors (whether DR or CR) performed satisfactorily. The chief limitation in performing these tests was that not all systems provided ready access to pixel values. Subjective tests include the use of the Leeds TO20. As part of this work, suggested reference values are provided to calculate the TO20 image quality factor. One consequence of moving from film screen to digital technologies is that the dynamic range of digital detectors is much wider, and increased exposures are no longer evident from changes in image quality. As such, AEC is a key parameter for CR and DR. Dose was measured using a standard phantom as a basic means of comparing systems. In order to assess the AEC performance, exit doses were also measured while varying phantom thickness. Signal-to-noise ratios (SNRs) were calculated on a number of systems where pixel values were available. SNR was affected by the selection of acquisition protocol. Comparisons between different technologies and collation of data will help refine acceptance thresholds and contribute to optimising dose and image quality. (authors)

Technical and diagnostic problems of X-ray radiography of children in medical practice

International Nuclear Information System (INIS)

Schuster, W.

An increase in biomedical paediatric radiography of 5-10% per year is expected and therefore it is necessary to look for new possibilities to reduce the dose with the aim to make an increase of radiation exposure impossible, a radiation exposure which would indeed have a very negative effect on the organism of children. Some reasons for the increased radiation sensivity of children are explained. To reduce the radiation exposure the author demands for the sector of children radiobiology that doctors and assistents should be trained in a right way, further a clear diagnosis and the best possible equipment. Concerning the last point various possibilities are presented. The special problem of biomedical radiography is shortly dealt with. At the end of his report the author gives some recommendations concerning the dose, dose capacity, filters which should be used. (MG) [de

Dosimetric evaluation in panoramic and tele-radiography procedures; Avaliacao dosimetrica em procedimentos de radiografia panoramica e teleradiografias

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Georgge Gomes

2004-07-01

The present work had as an objective to evaluate the skin surface entrance dose in panoramic and tele radiography procedures in three clinics in Recife - Pernambuco - Brazil, and to contribute with data for the determination of reference levels for super cited extra oral procedures, for this purpose, operational conditions in 3 clinics were evaluated in Recife, aiming to evaluate the existence and integrity of the radioprotection equipment, manner and conditions of image processing; and radiographic equipment parameters such as the dimension of the irradiation filed, the total filtration, the exposure time and the potential applied to the X ray tube. For an estimation of the skin entrance dose of the patient, the phantom Randon Alderson and thermoluminescence dosemeters were used. From these values and the conversion factors determined by the Monte Carlo technique, with the phantom MAX it was possible to estimate the dose absorbed in the organ due to the tele radiography procedures. Regarding panoramic radiography the study showed that the more elevated doses occurred in the parotid gland region which is near rotational venters. In the case of tele radiography the highest dose value occurred in the regions corresponding to the temporal lobe of the brain, followed by linfonodes, ears and parotid glands. The doses absorbed in the eyes and the thyroid gland were, 0.037 mGy and 0.002 mGy in Clinic A and 0.062 mGy and 0.003 mGy in Clinic C, respectively. Regarding equipment test, inadequacy was found in the beam collimation in Clinic A and in the reproducibility of the X ray exposure in Clinic C. The total filtration in both clinics was inadequate.(author)

A study on image quality and exposure dose of hard radiation radiography of the chest

International Nuclear Information System (INIS)

Hayashi, Taro; Ishida, Yuji; Maeda, Mika; Sakurai, Tatsuya; Kim, Chung Woon; Hwang, Jong Sun

1991-01-01

Experiment was conducted on the image quality and exposure dose following replacement of CaWO 4 system screen BH - III and BX - III which have so far been used for high - voltage hard - radiation quality radiography, with rare earth system screen KO750, combined with high contrast film SRH, while additional filter was altered, Cu 0.8 mm + Al 1.4 mm(HVL : AI 8.8 mm), Cu 1.3 mm + AI 1.0mm(HVL: AI 10.6mm) and Cu 1.8mm + AI 1.5mm(HVL: AI 11.4mm). AS a result, visual evaluation did not detect extreme changes in image quality under the respective condition (HVL : Al 8.8 mm ∼ AI 11.4 mm). It was noted, however, that surface exposure dose declined with an increase in the thickness of the additional filter, as it was 18.9 μGy at HVL Al 8.8 mm, 17.5 μGy at Al 10.6 mm and 15.7 μGy at Al 11.4 mm. Considering the limited rating of X-ray equipment and wear of machinery, however, the range of Cu 1.3 mm ∼ l.8 mm + AI 1.0 mm ∼ 1.5 mm(1/16 VL ∼ 1/32 VL) seemed to be a limit

Charged Particle Radiography

International Nuclear Information System (INIS)

Morris, Chris

2004-01-01

The Coulomb multiple scattering of charged particles as they pass through material allows them to be used as a radiographic probe. This forms the basis for a new kind of radiography that is finding application where conventional x-ray radiography is limited by flux or backgrounds. Charged-particle radiography is providing a versatile new probe that has advantages over conventional x-ray radiography for some unique application. Proton radiography has been used to make quantitative motion pictures of high explosive driven experiments and proves to be of great value for radiographing experiments that mock up nuclear weapon primaries for stockpile certification. By taking advantage of magnetic lens to magnify images and by using the very bright beams that can be made with electrons, charged-particle radiography may be useful for studying the fine spatial detail and very fast motion in laser driven implosion experiments at the National Ignition Facility. Finally, radiographs can be made using cosmic-ray muons for searching vehicles and cargo containers for surreptitious cargo of high z materials such as uranium or plutonium.

Tomosynthesis for the early detection of pulmonary emphysema: diagnostic performance compared with chest radiography, using multidetector computed tomography as reference.

Science.gov (United States)

Yamada, Yoshitake; Jinzaki, Masahiro; Hashimoto, Masahiro; Shiomi, Eisuke; Abe, Takayuki; Kuribayashi, Sachio; Ogawa, Kenji

2013-08-01

To compare the diagnostic performance of tomosynthesis with that of chest radiography for the detection of pulmonary emphysema, using multidetector computed tomography (MDCT) as reference. Forty-eight patients with and 63 without pulmonary emphysema underwent chest MDCT, tomosynthesis and radiography on the same day. Two blinded radiologists independently evaluated the tomosynthesis images and radiographs for the presence of pulmonary emphysema. Axial and coronal MDCT images served as the reference standard and the percentage lung volume with attenuation values of -950 HU or lower (LAA-950) was evaluated to determine the extent of emphysema. Receiver-operating characteristic (ROC) analysis and generalised estimating equations model were used. ROC analysis revealed significantly better performance (P pulmonary emphysema. The average sensitivity, specificity, positive predictive value and negative predictive value of tomosynthesis were 0.875, 0.968, 0.955 and 0.910, respectively, whereas the values for radiography were 0.479, 0.913, 0.815 and 0.697, respectively. For both tomosynthesis and radiography, the sensitivity increased with increasing LAA-950. The diagnostic performance of tomosynthesis was significantly superior to that of radiography for the detection of pulmonary emphysema. In both tomosynthesis and radiography, the sensitivity was affected by the LAA-950. • Tomosynthesis showed significantly better diagnostic performance for pulmonary emphysema than radiography. • Interobserver agreement for tomosynthesis was significantly higher than that for radiography. • Sensitivity increased with increasing LAA -950 in both tomosynthesis and radiography. • Tomosynthesis imparts a similar radiation dose to two projection chest radiography. • Radiation dose and cost of tomosynthesis are lower than those of MDCT.

Routine oblique radiography of the pediatric lumbar spine: is it necessary

International Nuclear Information System (INIS)

Roberts, F.F.; Kishore, P.R.S.; Cunningham, M.E.

1978-01-01

A series of 86 pediatric lumbar spine abnormalities was evaluated to determine the diagnostic benefit of radiography in oblique projection as compared to frontal-lateral projections alone. In only four patients was an abnormality apparent on the oblique view which had not already been demonstrated by the frontal-lateral series; each of these represented an isolated spondylolysis. Because the diagnostic yield was low at a patient cost of more than double the gonadal radiation dose, it is recommended that oblique views be eliminated in the routine radiography of the pediatric lumbar spine

Industrial radiography

International Nuclear Information System (INIS)

1992-01-01

Industrial radiography is a non-destructive testing (NDT) method which allows components to be examined for flaws without interfering with their usefulness. It is one of a number of inspection methods which are commonly used in industry to control the quality of manufactured products and to monitor their performance in service. Because of its involvement in organizing training courses in all the common NDT methods in regional projects in Asia and the Pacific and Latin America and the Caribbean and in many country programmes, the Agency is aware of the importance of standardizing as far as possible the syllabi and training course notes used by the many experts who are involved in presenting the training courses. IAEA-TECDOC-628 ''Training Guidelines in Non-destructive Testing'' presents syllabi which were developed by an Agency executed UNDP project in Latin America and the Caribbean taking into account the developmental work done by the International Committee for Non-destructive Testing. Experience gained from using the radiography syllabi from TECDOC-628 at national and regional radiography training courses in the Agency executed UNDP project in Asia and the Pacific (RAS/86/073) showed that some guidance needed to be given to radiography experts engaged in teaching at these courses on the material which should be covered. The IAEA/UNDP Asia and Pacific Project National NDT Coordinators therefore undertook to prepare Radiography Training Course Notes which could be used by experts to prepare lectures for Level 1,2 and 3 radiography personnel. The notes have been expanded to cover most topics in a more complete manner than that possible at a Level 1, 2 or 3 training course and can now be used as source material for NDT personnel interested in expanding their knowledge of radiography. Refs, figs and tabs

Gonad shielding in paediatric pelvic radiography : Disadvantages prevail over benefit

NARCIS (Netherlands)

Frantzen, M.J.; Robben, S.; Postma, A.A.; Zoetelief, J.; Wildberger, J.E.; Kemerink, G.J.

2012-01-01

Objective To re-evaluate gonad shielding in paediatric pelvic radiography in terms of attainable radiation risk reduction and associated loss of diagnostic information. Methods A study on patient dose and the quality of gonad shielding was performed retrospectively using 500 pelvic radiographs of

Strategies for dose reduction in ordinary radiographic examinations using CR and DR

International Nuclear Information System (INIS)

Willis, C.E.

2004-01-01

Uncoupling of display from acquisition in computed radiography (CR) and digital radiography (DR) introduces the potential for systematic overexposure without necessarily compromising image quality. Although the magnitude of radiation doses in general radiography is low compared to computed tomography and fluoroscopy, the dose to the patient is more critical in pediatric examinations than in adults, because of the greater radiosensitivity of children. This manuscript examines a variety of countermeasures for managing radiation doses in pediatric CR and DR examinations, including use of derived exposure indicators, modifications of imaging practice, and development of more efficient radiographic detectors. (orig.)

Absorbed radiation by various tissues during simulated endodontic radiography

International Nuclear Information System (INIS)

Torabinejad, M.; Danforth, R.; Andrews, K.; Chan, C.

1989-01-01

The amount of absorbed radiation by various organs was determined by placing lithium fluoride thermoluminescent chip dosimeters at selected anatomical sites in and on a human-like X-ray phantom and exposing them to radiation at 70- and 90-kV X-ray peaks during simulated endodontic radiography. The mean exposure dose was determined for each anatomical site. The results show that endodontic X-ray doses received by patients are low when compared with other radiographic procedures

Initial experiences in clinical application of the THORAX-FD: flat-panel detector radiography in thoracic diagnosis

International Nuclear Information System (INIS)

Herrmann, K.A.; Staebler, A.; Bonel, H.; Kulinna, C.; Holzknecht, N.; Reiser, M.F.; Geiger, B.; Boehm, S.; Maschke, M.

2000-01-01

The flat-panel detector closes the gap between radiography and the digital diagnostics equipment currently in use. In addition to the dose reduction that can be expected, the availability of diagnostic information in digital form enables the user to optimize the clinical workflow and to network radiography directly with a digital archiving and communication system. (orig.)

Dose-rate-dependent damage of cerium dioxide in the scanning transmission electron microscope.

Science.gov (United States)

Johnston-Peck, Aaron C; DuChene, Joseph S; Roberts, Alan D; Wei, Wei David; Herzing, Andrew A

2016-11-01

Beam damage caused by energetic electrons in the transmission electron microscope is a fundamental constraint limiting the collection of artifact-free information. Through understanding the influence of the electron beam, experimental routines may be adjusted to improve the data collection process. Investigations of CeO 2 indicate that there is not a critical dose required for the accumulation of electron beam damage. Instead, measurements using annular dark field scanning transmission electron microscopy and electron energy loss spectroscopy demonstrate that the onset of measurable damage occurs when a critical dose rate is exceeded. The mechanism behind this phenomenon is that oxygen vacancies created by exposure to a 300keV electron beam are actively annihilated as the sample re-oxidizes in the microscope environment. As a result, only when the rate of vacancy creation exceeds the recovery rate will beam damage begin to accumulate. This observation suggests that dose-intensive experiments can be accomplished without disrupting the native structure of the sample when executed using dose rates below the appropriate threshold. Furthermore, the presence of an encapsulating carbonaceous layer inhibits processes that cause beam damage, markedly increasing the dose rate threshold for the accumulation of damage. Published by Elsevier B.V.

Digital radiography: study of an alternative technique to conventional radiography

International Nuclear Information System (INIS)

Banchet, J.; Tisseur, D.; Thomas, A.

2009-01-01

Digital radiography, already in use in many industrial applications, appears as a potential alternative technique to conventional radiography in the nuclear field (and more especially to the inspection of welded joints). The advantages of digital radiography are a reduced explosion risk (due to the use of lower energy and activity sources), a lower installation time, a reduced exclusion zone, and the absence of effluents. However, to the contrary of the US case, this technique may not be used in France as it is not referenced in the regulating codes (RCCM, etc.). Areva has launched a R and D study in order to characterize the equivalencies between digital and conventional radiography. First results of this study are given

Neutron radiography, techniques and applications

International Nuclear Information System (INIS)

Domanus, J.C.

1987-10-01

After describing the principles of the ''in pool'' and ''dry'' installations, techniques used in neutron radiography are reviewed. Use of converter foils with silver halide films for the direct and transfer methods is described. Advantages of the use of nitrocellulose film for radiographying radioactive objects are discussed. Dynamic imaging is shortly reviewed. Standardization in the field of neutron radiography (ASTM and Euratom Neutron Radiography Working Group) is described. The paper reviews main fields of use of neutron radiography. Possibilities of use of neutron radiography at research reactors in various scientific, industrial and other fields are mentioned. Examples are given of application of neutron radiography in industry and the nuclear field. (author)

Basic principles of industrial radiography

International Nuclear Information System (INIS)

Bestbier, P.

1983-01-01

X-ray radiography and gamma radiography are used in industrial radiography. X-rays and gamma rays have the ability to penetrate materials and be absorbed by different densities. This characteristic makes them useful tools in industrial and medical radiography. The sources used for the generation of x-rays, gamma rays and radioisotopes are discussed. Films are one of the recording methods of x-radiography. The article also deals with advantages and disadvantages of radiography. Factors governing radiation exposure includes: the type of radiation source, material to be radiographed, distance, film, and the method for development. International specifications are also responsible for strict control over the standard of workmanship in industrial radiography

Radiography of scoliosis: comparative dosimetry between conventional technique and digital fluorography

International Nuclear Information System (INIS)

Gorincour, G.; Paris, M.; Aschero, A.; Bourliere, B.; Devred, P.; Petit, P.; Barrau, K.; Auquier, P.; Waultier, S.; Bourrelly, M.; Mundler, O.; Viehweger, E.; Jouve, J.L.; Bollini, G.

2007-01-01

Objective. Compare the irradiation delivered in conventional radiography and digital radiography by image intensifier during a scoliosis workup. Patients and Methods. Our prospective randomized study included 105 patients, all of whom were identified according to socio-demographic parameters as well as criteria evaluating the quality of the full front spinal x-ray at PA incidence. The entry dose at the scapula and the exit dose in inter-orbital, thyroid, mammary, and hypo-gastric projection was measured by thermoluminescent dosimeters. Results. The results of 71 girls and 28 boys, aged a mean 13.8 years with a mean weight of 47 kg were analyzed. At equal image quality, the entry dose was not significantly different between the two techniques; the mean exit dose reduction was 64% during digital acquisition. This reduction involved the inter-orbital (162%), mammary (43%), and thyroid (309%) regions. However, this system is more irradiating in the hypo-gastric region (34%). Conclusion. The dosimetric evaluation of the different imaging techniques used to explore the entirety of the spine should be part of radiologists' quality standard used to document their work and their choices. (authors)

Digital chest radiography: flat-panel detectors or conventional radiographs

International Nuclear Information System (INIS)

Schaefer-Prokop, C.; Uffmann, M.; Sailer, J.; Kabalan, N.; Herold, C.; Prokop, M.

2003-01-01

Flat panel detectors are characterized by improved handling and increased dose efficiency. This allows for increasing of work flow efficiency and for reducing the exposure dose by about 50% compared to current systems with a sensitivity of 400. Whether the increased dose efficiency should be used to reduce acquisition dose or to increase image quality in the chest, will be shown by further clinical experience and will be also determined by the subjective preference of the radiologists. The decreased level of image noise opens new perspectives for image processing that way that elaborated multifrequency processing allows for optimizing the display of very small and low contrast structures that was so far limited by overlying image noise. Specialized applications of dual energy subtraction and temporal subtraction will also profit by the new detector technology and will be further driven forward in context with applications such as computed assisted diagnosis even though this is currently not yet broadly applied. Storage phosphor radiography still represents an important alternative technique based on its larger flexibility with respect to equipment configuration, its broader application options in intensive care and emergency radiology and due to economic reasons. These facts are further underlined by the fact that image quality also in storage phosphor radiography could be constantly increased by improving detector technology and image processing and consequently has a high standard. (orig.) [de

Absorbed dose to the skin in radiological examinations of upper and lower gastrointestinal tract

International Nuclear Information System (INIS)

Zonca, G.; Brusa, A.; Somigliana, A.; Pasqualotto, C.; Sichirollo, A.E.; Bellomi, M.; Cozzi, G.; Severini, A.

1995-01-01

Absorbed doses to the skin in radiological examinations of the upper and lower gastronintestinal tract in conventional and digital radiology are evaluated and compared. Absorbed doses were measured with LiF thermoluminescence dosemeters placed on the lower pelvis, umbilicus and forehead of the patient to evaluate the absorbed dose in and outside the primary beam. On 10 patients a reduction in absorbed dose of about 34% for double contrast barium enema and of 66% for upper gastrointestinal tract examinations was revealed with digital radiography equipment. In our working conditions the lower dose requirement for digital radiography is mainly due to image intensifiers and television chains and also, due to our equipment settings, to the dose reduction with digital spot fluorography compared with conventional spot film radiography. (Author)

Specific radiography technique

International Nuclear Information System (INIS)

Abdul Nassir Ibrahim; Azali Muhammad; Ab. Razak Hamzah; Abd. Aziz Mohamed; Mohamad Pauzi Ismail

2008-01-01

Beside radiography testing using x-ray machine and gamma source, there are several technique that developed specifically to complete the testing that cannot be done with the two earlier. This technique was specific based on several factor, for the example, the advantages of neutron and electron using to show the image was unique compare to x-ray and gamma. Besides that, these special radiography techniques maybe differ in how to detect the radiation get through the object. These technique can used to inspect thin or specimen that contained radioactive material. There are several technique will discussed in this chapter such as neutron radiography, electron radiography, fluoroscopy and also autoradiography.

Bone X-Ray (Radiography)

Medline Plus

Full Text Available ... Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small ... X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive medical ...

Bone X-Ray (Radiography)

Science.gov (United States)

... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small ... of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive ...

An epidemiological study for the reduction of population radiation dose

International Nuclear Information System (INIS)

Gamo, Makoto

1989-01-01

The correlation of tube voltage with patient exposure was studied using effective dose as an indicator of dose reduction in intraoral radiography. The results were as follows: l. The salivary gland tissues contributed the most to the effective dose of intraoral radiography. 2. In the 50 to 90 kV range, there was no appreciable correlation between tube voltage and effective dose. 3. Therefore, it was suggested that adjusting the tube voltage for maximum image quality does not effect radiation protection. 4. This study reconfirmed the fact that increases in voltages up to 90 kV reduce skin doses. (author)

Digital radiography

International Nuclear Information System (INIS)

Kusano, Shoichi

1993-01-01

Firstly, from an historic point of view, fundamental concepts on digital imaging were reviewed to provide a foundation for discussion of digital radiography. Secondly, this review summarized the results of ongoing research in computed radiography that replaces the conventional film-screen system with a photo-stimulable phosphor plate; and thirdly, image quality, radiation protection, and image processing techniques were discussed with emphasis on picture archiving and communication system environment as our final goal. Finally, future expansion of digital radiography was described based on the present utilization of computed tomography at the National Defense Medical College Hospital. (author) 60 refs

Radiography - A conceptual approach

Energy Technology Data Exchange (ETDEWEB)

Ahonen, Sanna-Mari [Department of Nursing Science and Health Administration, University of Oulu, P.O. Box 5000, FIN-90014 (Finland)], E-mail: sanna-mari.ahonen@oulu.fi

2008-11-15

Aim: The purpose of this article is to describe interdisciplinary comparison of the attributes of the concept of radiography in health sciences, physics and technology on the grounds of concept analysis. Background: The concept of radiography is widely used in health sciences, physics and technology. However, the content of the concept may vary. In order to clarify the concept of radiography, the concept must be systematically examined and defined in linguistic form. Method: The concept of radiography was analysed by using the evolutionary method of concept analysis. The data were collected through discretionary sampling and consisted of literature and Internet pages. Qualitative content analysis was employed for analysing the data. Findings: As a result of concept analysis, the concept of radiography in health sciences was determined as expertise of radiographers in the use of radiation, which is dual, dynamic, social and situation-related in nature, and typically based on versatile synthesis. Regarding the attributes identified, the concept of radiography has both similarities and differences between health sciences, physics and technology. Conclusions: The concept of radiography was found to be more abstract, wider, more complex and more radiographer-centred in health sciences than in other disciplines. The content of the concept of radiography seems to vary according to the discipline.

Radiography - A conceptual approach

International Nuclear Information System (INIS)

Ahonen, Sanna-Mari

2008-01-01

Aim: The purpose of this article is to describe interdisciplinary comparison of the attributes of the concept of radiography in health sciences, physics and technology on the grounds of concept analysis. Background: The concept of radiography is widely used in health sciences, physics and technology. However, the content of the concept may vary. In order to clarify the concept of radiography, the concept must be systematically examined and defined in linguistic form. Method: The concept of radiography was analysed by using the evolutionary method of concept analysis. The data were collected through discretionary sampling and consisted of literature and Internet pages. Qualitative content analysis was employed for analysing the data. Findings: As a result of concept analysis, the concept of radiography in health sciences was determined as expertise of radiographers in the use of radiation, which is dual, dynamic, social and situation-related in nature, and typically based on versatile synthesis. Regarding the attributes identified, the concept of radiography has both similarities and differences between health sciences, physics and technology. Conclusions: The concept of radiography was found to be more abstract, wider, more complex and more radiographer-centred in health sciences than in other disciplines. The content of the concept of radiography seems to vary according to the discipline

Pelvic measurements by means of digital radiography (CT topogram)

Energy Technology Data Exchange (ETDEWEB)

Reisner, K; Fettig, O; Bartscher, K H; Knappschneider, U

1985-05-01

Radiographic examination during pregnancy and pelvimetry before pregnancy are still required for particular indications. The use of digital radiography (lateral topogram on CT) reduces the radiation dose to the foetus and ovaries by a factor of 10 to 100, as compared with conventional pelvimetry, as described by Guthmann. The accuracy of this method is satisfactory, the technique is simple, it is rapid and is easy for the patient, particularly for pregnant women. As long as pelvimetry is not possible without ionising radiation, we consider pelvimetry with digital radiography, when strictly indicated, to be acceptable. In order to determine the transverse diameter of the pelvis, a single additional CT cut through the narrowest part of the pelvis is suggested.

Construction of anthropomorphic hybrid, dual-lattice voxel models for optimizing image quality and dose in radiography

Science.gov (United States)

Petoussi-Henss, Nina; Becker, Janine; Greiter, Matthias; Schlattl, Helmut; Zankl, Maria; Hoeschen, Christoph

2014-03-01

In radiography there is generally a conflict between the best image quality and the lowest possible patient dose. A proven method of dosimetry is the simulation of radiation transport in virtual human models (i.e. phantoms). However, while the resolution of these voxel models is adequate for most dosimetric purposes, they cannot provide the required organ fine structures necessary for the assessment of the imaging quality. The aim of this work is to develop hybrid/dual-lattice voxel models (called also phantoms) as well as simulation methods by which patient dose and image quality for typical radiographic procedures can be determined. The results will provide a basis to investigate by means of simulations the relationships between patient dose and image quality for various imaging parameters and develop methods for their optimization. A hybrid model, based on NURBS (Non Linear Uniform Rational B-Spline) and PM (Polygon Mesh) surfaces, was constructed from an existing voxel model of a female patient. The organs of the hybrid model can be then scaled and deformed in a non-uniform way i.e. organ by organ; they can be, thus, adapted to patient characteristics without losing their anatomical realism. Furthermore, the left lobe of the lung was substituted by a high resolution lung voxel model, resulting in a dual-lattice geometry model. "Dual lattice" means in this context the combination of voxel models with different resolution. Monte Carlo simulations of radiographic imaging were performed with the code EGS4nrc, modified such as to perform dual lattice transport. Results are presented for a thorax examination.

Accidents in industrial radiography in Brazil from 2005 to 2010

International Nuclear Information System (INIS)

Lopes, Ricardo Tadeu

2011-01-01

Analysis of accidents occurring in industrial radiography in Brazil from 2005 until 2010 led to the study of the main characteristics of the events, their risks and dangers. This study outlines the main doubts on the subject, through a simplified analysis of the contents of high dose reports sent to CNEN by the companies that provide services for industrial radiography and from examining the growing number of radioactive sources for industrial radiography in Brazil, over this period. We classified the recorded events, as incidents, accidents, negligence, sabotage, and others, and studied their main consequences. We concluded that from 76 accidents that occurred during that period - 25 were real accidents, 13 minor accidents and 22 were inadvertent incidents. We found that the rate of growth in the number of sources is much greater than the rate of growth of accidents, with a ratio of 7.57 between them. The continuation of this study over some years, will allow the construction of a pyramid of accidents like the one developed by the Insurance Company of North America, specifically for industrial radiography to forecast the number of incidents and accidents that lead to serious or fatal injury. (author)

Bone X-Ray (Radiography)

Medline Plus

Full Text Available ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very ... of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive ...

Bone X-Ray (Radiography)

Medline Plus

Full Text Available ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small ... of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive ...

Gamma radiography and its technological application

International Nuclear Information System (INIS)

Courtois, G.

1962-01-01

After the presentation of gamma radiography and X-ray radiography, the author compare both techniques showing, in particular, the greater utility of gamma radiography in industrial diagnostic and more particularly on works site diagnostic. Problem of using radiography and safety consideration will be studied. Figures shows two radiography equipment which have been designed for gamma radiography respecting the safety regulations required by the Radioisotope Inter-ministerial Commission. In the second part, different techniques and uses of gamma radiography are briefly described : xerography, neutron radiography, fluoroscopy and imaging amplifier, tomography, betatrons and linear accelerators. Cost analysis will discussed in conclusion. (M.P.)

Digital radiography in NDT applications

International Nuclear Information System (INIS)

Deprins, E.

2004-01-01

A lot of film radiography could be replaced by today's technologies in the field of digital radiography. Only few of these applications have indeed replaced film. The choice to go digital depends on cost, quality requirement, workflow and throughput. Digital images offer a lot of advantages in terms of image manipulation and workflow. But despite the many advantages, a lot of considerations are needed before someone can decide to convert his organization from conventional to digital radiography. This paper gives an overview of all different modalities that can be used in digital radiography with today's technologies, together with the experiences of the pioneers of digital radiography. Film Scanning, Computed Radiography and Digital Radiography by using of different kinds of flat panel detectors all have their specific application fields and customers. What is the status of the technology today, which advantages brings digital radiography, and which are the limitations radiographers have to consider when replacing film by digital systems. (author)

International Neutron Radiography Newsletter

DEFF Research Database (Denmark)

Domanus, Joseph Czeslaw

1986-01-01

At the First World Conference on Neutron Radiography i t was decided to continue the "Neutron Radiography Newsletter", published previously by J.P. Barton, as the "International Neutron Radiography Newsletter" (INRNL), with J.C. Doraanus as editor. The British Journal of Non-Destructive Testing...

Estimating pediatric entrance skin dose from digital radiography examination using DICOM metadata: A quality assurance tool

Energy Technology Data Exchange (ETDEWEB)

Brady, S. L., E-mail: samuel.brady@stjude.org; Kaufman, R. A., E-mail: robert.kaufman@stjude.org [Department of Diagnostic Imaging, St. Jude Children’s Research Hospital, Memphis, Tennessee 38105 (United States)

2015-05-15

Purpose: To develop an automated methodology to estimate patient examination dose in digital radiography (DR) imaging using DICOM metadata as a quality assurance (QA) tool. Methods: Patient examination and demographical information were gathered from metadata analysis of DICOM header data. The x-ray system radiation output (i.e., air KERMA) was characterized for all filter combinations used for patient examinations. Average patient thicknesses were measured for head, chest, abdomen, knees, and hands using volumetric images from CT. Backscatter factors (BSFs) were calculated from examination kVp. Patient entrance skin air KERMA (ESAK) was calculated by (1) looking up examination technique factors taken from DICOM header metadata (i.e., kVp and mA s) to derive an air KERMA (k{sub air}) value based on an x-ray characteristic radiation output curve; (2) scaling k{sub air} with a BSF value; and (3) correcting k{sub air} for patient thickness. Finally, patient entrance skin dose (ESD) was calculated by multiplying a mass–energy attenuation coefficient ratio by ESAK. Patient ESD calculations were computed for common DR examinations at our institution: dual view chest, anteroposterior (AP) abdomen, lateral (LAT) skull, dual view knee, and bone age (left hand only) examinations. Results: ESD was calculated for a total of 3794 patients; mean age was 11 ± 8 yr (range: 2 months to 55 yr). The mean ESD range was 0.19–0.42 mGy for dual view chest, 0.28–1.2 mGy for AP abdomen, 0.18–0.65 mGy for LAT view skull, 0.15–0.63 mGy for dual view knee, and 0.10–0.12 mGy for bone age (left hand) examinations. Conclusions: A methodology combining DICOM header metadata and basic x-ray tube characterization curves was demonstrated. In a regulatory era where patient dose reporting has become increasingly in demand, this methodology will allow a knowledgeable user the means to establish an automatable dose reporting program for DR and perform patient dose related QA testing for

Qualitative discussion of quantitative radiography

International Nuclear Information System (INIS)

Berger, H.; Motz, J.W.

1975-01-01

Since radiography yields an image that can be easily related to the tested object, it is superior to many nondestructive testing techniques in revealing the size, shape, and location of certain types of discontinuities. The discussion is limited to a description of the radiographic process, examination of some of the quantitative aspects of radiography, and an outline of some of the new ideas emerging in radiography. The advantages of monoenergetic x-ray radiography and neutron radiography are noted

Radiation Safety in Industrial Radiography. Specific Safety Guide (French Edition); Surete radiologique en radiographie industrielle

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-05-15

This Safety Guide provides recommendations for ensuring radiation safety in industrial radiography used in non-destructive testing. This includes industrial radiography work that utilizes X ray and gamma sources, both in Horizontal-Ellipsis shielded facilities that have effective engineering controls and in outside shielded facilities using mobile sources. Contents: 1. Introduction; 2. Duties and responsibilities; 3. Safety assessment; 4. Radiation protection programme; 5. Training and qualification; 6. Individual monitoring of workers; 7. Workplace monitoring; 8. Control of radioactive sources; 9. Safety of industrial radiography sources and exposure devices; 10. Radiography in shielded enclosures; 11. Site radiography; 12. Transport of radioactive sources; 13. Emergency preparedness and response; Appendix: IAEA categorization of radioactive sources; Annex I: Example safety assessment; Annex II: Overview of industrial radiography sources and equipment; Annex III: Examples of accidents in industrial radiography.

Radiography at CERN

CERN Multimedia

HSE Unit

2014-01-01

What is industrial radiography? It is a non-destructive method with a wide variety of applications, such as inspecting the quality of a weld. It uses high-energy radioactive sources or an X-ray generator.   Is this inspection technique used at CERN? Yes, it is widely used at CERN by the EN-MME Group, which outsources the work to one or more companies, depending on the workload. Is it possible to carry out radiography anywhere at CERN? Yes, it is possible to carry out radiography in any building/accelerator/experiment area at CERN (including in areas which are not normally subject to radiological hazards). When is radiography carried out? It normally takes place outside of working hours (7 p.m. to 6 a.m.). How will I know if radiography is taking place in my building? If this activity is planned in a CERN building, notices will be affixed to all of its main entrance doors at least 24 hours in advance. What are the risks? There is a risk of exposure to very high levels of radiation, dep...

Radiological protection procedures for industrial applications of computed radiography; Procedimentos de protecao radiologica em aplicacoes industriais da radiografia computadorizada

Energy Technology Data Exchange (ETDEWEB)

Aquino, Josilto Oliveira de

2009-03-15

Due to its very particular characteristics, industrial radiography is responsible for roughly half of the relevant accidents in nuclear industry, in developed as well as in developing countries, according to the International Atomic Energy Agency (IAEA). Thus, safety and radiological protection in industrial gamma radiography have been receiving especial treatment by regulatory authorities of most Member States. The main objective of the present work was to evaluate, from the radioprotection point of view, the main advantages of computed radiography (CR) for filmless industrial radiography. In order to accomplish this, both techniques, i.e. conventional and filmless computed radiography were evaluated and compared through practical studies. After the studies performed at the present work it was concluded that computed radiography significantly reduces the inherent doses, reflecting in smaller restricted areas and costs, with consequent improvement in radiological protection and safety. (author)

Protection of gonads in radiography of the pelvis

International Nuclear Information System (INIS)

Correll, R.; Plischke, U.; Dresel, H.; Joos, M.

1976-01-01

The effectiveness of a new device for the protection of gonads has been tested by measuring doses on the water-phantom and on patients. The lead protector is applied below the light-source and protects the gonads in pelvic radiography. The reduction of dosage corresponds to the usual leadprotectors. It should be particularly useful in ortopedics, since it is simple and hygienic. (orig.) [de

Efficacy of daily bedside chest radiography as visualized by digital luminescence radiography

International Nuclear Information System (INIS)

Kirchner, J.; Stueckle, C.A.; Schilling, E.M.; Peters, J.

2001-01-01

To determine the diagnostic impact of daily bedside chest radiography in comparison with digital luminescence technique (DLR; storage phosphor radiography) and conventional film screen radiography, a prospective randomized study was completed in 210 mechanically ventilated patients with a total of 420 analysed radiographs. The patients were allocated to two groups: 150 patients underwent DLR, and 60 patients underwent conventional film screen radiography. Radiological analysis was performed consensually and therapeutic efficacy was assessed by the clinicians. There was no statistical significant difference between the frequency of abnormal findings seen on DLR and conventional film screen radiography. In total, 448 abnormal findings were present in 249 of 300 DLR and 97 of 120 conventional film screen radiographs. The most common findings were signs of overhydration (41 %), pleural effusion (31%), partial collapse of the lung (11%) and pneumothorax (2%). One hundred and twenty-three of 448 (27%) of these abnormal findings were thought to have a considerable impact on patient management. The high rate of abnormal findings with significant impact on patient management suggests that the use of daily bedside chest radiography may be reasonable. Copyright (2001) Blackwell Science Pty Ltd

Military radiography

International Nuclear Information System (INIS)

Anon.

1993-01-01

Historic military uses of radiography are discussed in this chapter: Battle of Adowa in 1986 was the first. Besides describing the early campaigns in which radiography was used, the author discusses the problems faced: a reliable source of electricity; the problems of extreme heat; moving and breakage of equipment. Numerous historical photographs are included. 9 refs

Comparison of the quality of the chest film between digital radiography and conventional high kV radiography

International Nuclear Information System (INIS)

Zeng Qingsi; Cen Renli; Chen Ling; He Jianxun; Lin Hanfei

2003-01-01

Objective: To evaluate the quality and usefulness of direct digital radiography system in roentgenogram of chest in clinical practice. Methods: 1000 cases of chest roentgenograms with digital radiography and high kV conventional radiography were selected for analysis by 3 senior radiologists. Results: 1. With digital radiography system, the quality of chest film was assessed as grade A in 50.6%, grade B in 38.5%, grade C in 10.9%, and no waste film. 2. With conventional high kV radiography, the quality of chest film was assessed as grade A in 41.1%, grade B in 44.1%, grade C in 13.3%, and waste film in 1.5%. The direct digital radiography was statistically superior to the conventional high kV radiography. 3. The fine structure of the lungs could be revealed in 100.0% of chest roentgenogram with direct digital radiograph system, which was significantly higher than that acquired with the conventional high KV radiography (78.6%, P < 0.001). Conclusion: Direct digital radiography could provide the chest film with better quality than that with the conventional high kV radiography. The direct digital radiography system is easy to operate, fast in capturing imaging and could provide post-processing techniques, which will facilitate the accurate diagnosis of chest radiography

High-energy test of proton radiography concepts

International Nuclear Information System (INIS)

Amann, J.F.; Atencio, L.G.; Espinoza, C.J.

1997-01-01

This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal of this work was to demonstrate the use of high energy protons to produce radiographs of heavy metal test objects. The authors executed a proof-of-principle experiment using GeV proton beams available at the Brookhaven National Laboratory Alternating Gradient Synchrotron (AGS). The experiment produced proton radiographs of a suitably dense, unclassified test object. The experiment tested capabilities in data collection, image reconstruction, and hydro-code simulation and validated models of high-energy proton radiography. A lens was designed using existing quadrupole magnets, constructed on the A1 beam line of the AGS and used to image 10-GeV protons. The results include: (1) images made with an integrating detector, (2) measurements of the background and measurements of the resolution functions, and (3) forward model fits to the transmission data. In all cases the results agree with initial estimates and provide strong support for the utility of proton radiography as a new hydrotest diagnostic

The experiment of grid characteristics for high-voltage radiography of chest

International Nuclear Information System (INIS)

Kim, Jung Min; Ahn, Bong Seon

1992-01-01

Grids can improve the diagnostic quality of chest radiography by trapping the greater part of scattered radiation thus providing more detailed chest radiographic images. It is most effective method of reduce the scatter ratio but must increase the expour factor. The benefit of use of grid is improve the contrast and the loss is increase of patient dose. In chest radiography especially hard quality high voltage radiography it will have to be considered to select the optimum grid with view point of benefit and loss. In this experiment, auther got some result of characteristics about 4 different grids with film method. 1. There was no difference the scatter ratio in case of no grid and the scatter ratio was about 60 % 2. 16 : 1 grid was excellent of scatter reduction factor in high voltage chest radiography, next was 10 : 1, CROSS, MICRO FINE grid have low scatter reduction rate compare to 16:1,10:1 grid. 3. The bucky factor of CROSS grid in accordance of kVp was find out the highest in 4 grids, on the contrary 10 : 1 grid was profitable to the. exposure does. 4. With careful consideration in the point of scatter reduction rate and bucky factor, auther suggest the 10 : 1 linear grid on the use of chest radiography in 80∼120 kVp, 16 : 1 grid in 120∼140 kVp

Improvement of single detector proton radiography by incorporating intensity of time-resolved dose rate functions

Science.gov (United States)

Zhang, Rongxiao; Jee, Kyung-Wook; Cascio, Ethan; Sharp, Gregory C.; Flanz, Jacob B.; Lu, Hsiao-Ming

2018-01-01

Proton radiography, which images patients with the same type of particles as those with which they are to be treated, is a promising approach to image guidance and water equivalent path length (WEPL) verification in proton radiation therapy. We have shown recently that proton radiographs could be obtained by measuring time-resolved dose rate functions (DRFs) using an x-ray amorphous silicon flat panel. The WEPL values were derived solely from the root-mean-square (RMS) of DRFs, while the intensity information in the DRFs was filtered out. In this work, we explored the use of such intensity information for potential improvement in WEPL accuracy and imaging quality. Three WEPL derivation methods based on, respectively, the RMS only, the intensity only, and the intensity-weighted RMS were tested and compared in terms of the quality of obtained radiograph images and the accuracy of WEPL values. A Gammex CT calibration phantom containing inserts made of various tissue substitute materials with independently measured relative stopping powers (RSP) was used to assess the imaging performances. Improved image quality with enhanced interfaces was achieved while preserving the accuracy by using intensity information in the calibration. Other objects, including an anthropomorphic head phantom, a proton therapy range compensator, a frozen lamb’s head and an ‘image quality phantom’ were also imaged. Both the RMS only and the intensity-weighted RMS methods derived RSPs within  ±  1% for most of the Gammex phantom inserts, with a mean absolute percentage error of 0.66% for all inserts. In the case of the insert with a titanium rod, the method based on RMS completely failed, whereas that based on the intensity-weighted RMS was qualitatively valid. The use of intensity greatly enhanced the interfaces between different materials in the obtained WEPL images, suggesting the potential for image guidance in areas such as patient positioning and tumor tracking by proton

Radiogenic cancer induction associated with spinal radiography: a quantitative analysis

International Nuclear Information System (INIS)

Fickel, T.E.

1988-01-01

Computations of organ-specific radiation absorption by lung, breast, thyroid, active bone marrow and uterine tissues are used to rank sectional and full spine radiographic procedures according to their potentials for cancer induction. Assuming that the dose-effect relationship of radiation damage is linear and lacks a threshold effect, the prospective and retrospective carcinogenicities of commonly ordered spinal series are estimated. Cervical radiography is demonstrated to pose the least hazard to the patient, while full spine and lumbar (five views) procedures have the greatest. Organs most at risk as a result of spinal radiography are lung (thoracic and full spine), colon (lumbar and full spine), breast (thoracic and full spine), and prostate (full spine and lumbar)

Radiation dose of digital tomosynthesis for sinonasal examination: comparison with multi-detector CT.

Science.gov (United States)

Machida, Haruhiko; Yuhara, Toshiyuki; Tamura, Mieko; Numano, Tomokazu; Abe, Shinji; Sabol, John M; Suzuki, Shigeru; Ueno, Eiko

2012-06-01

Using an anthropomorphic phantom, we have investigated the feasibility of digital tomosynthesis (DT) of flat-panel detector (FPD) radiography to reduce radiation dose for sinonasal examination compared to multi-detector computed tomography (MDCT). A female Rando phantom was scanned covering frontal to maxillary sinus using the clinically routine protocol by both 64-detector CT (120 kV, 200 mAs, and 1.375-pitch) and DT radiography (80 kV, 1.0 mAs per projection, 60 projections, 40° sweep, and posterior-anterior projections). Glass dosimeters were used to measure the radiation dose to internal organs including the thyroid gland, brain, submandibular gland, and the surface dose at various sites including the eyes during those scans. We compared the radiation dose to those anatomies between both modalities. In DT radiography, the doses of the thyroid gland, brain, submandibular gland, skin, and eyes were 230 ± 90 μGy, 1770 ± 560 μGy, 1400 ± 80 μGy, 1160 ± 2100 μGy, and 112 ± 6 μGy, respectively. These doses were reduced to approximately 1/5, 1/8, 1/12, 1/17, and 1/290 of the respective MDCT dose. For sinonasal examinations, DT radiography enables dramatic reduction in radiation exposure and dose to the head and neck region, particularly to the lens of the eye. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Radiography with polarised neutrons

International Nuclear Information System (INIS)

Schulz, Michael L.

2010-01-01

In this thesis I present a new technique for the spatially resolved investigation of the magnetic properties of bulk samples. Standard one dimensional neutron depolarisation analysis is combined with neutron radiography to a method we call Neutron Depolarisation Imaging (NDI). The experimental setup which was installed at the neutron radiography beam line ANTARES at FRM II consists of a double crystal monochromator, neutron polariser, spin flipper, polarisation analyser and a position sensitive CCD detector. A comprehensive discussion of the requirements for these components is given and the limitations of the method are shown. The maximum spatial resolution which can be achieved with a neutron radiography setup is determined by the collimation of the neutron beam and the distance between sample and detector. Different types of polarisers have been tested and their advantages and disadvantages are discussed. A double crystal monochromator and a new type of polariser employing polarising neutron supermirrors based on the principle of an optical periscope were developed and tested during this work. Furthermore, NDI measurements on various samples of the weakly ferromagnetic materials Pd 1-x Ni x and Ni 3 Al are presented. Neutron depolarisation radiography and tomography measurements were conducted with a spatial resolution as high as 0.3 mm on Pd 1-x Ni x and Ni 3 Al samples. The feasibility of NDI experiments under hydrostatic pressures up to 10 kbar was shown on a sample of Ni 3 Al using a modified Cu:Be clamp cell. A decrease of the ordering temperature by 2 K under hydrostatic pressure was determined from the NDI measurements and shows the potential of the method for further high pressure experiments. Additionally a method was developed which in principle allows to obtain the intrinsic dependence of the ordering temperature T C on the ordered moment Ms from NDI measurements on inhomogeneous samples containing regions with different ordering temperatures. This

The profile of indications for radiography in the Neonatal Intensive ...

African Journals Online (AJOL)

DOI:10.7196/SAJCH.467. Conventional portable radiography remains a key diagnostic tool for ... in uence the estimated e ective dose and therefore the risk of cancer following radiation ..... to most radiation, the liver, breast and stomach were the ... More research on the e cacy of ultrasonography as an alternative diagnostic ...

The stationary neutron radiography system

International Nuclear Information System (INIS)

Weeks, A.A.; Newell, D.L.; Heidel, C.C.

1990-01-01

To provide the high intensity neutron beam and support systems necessary for radiography, the Stationary Neutron Radiography System was constructed at McClellan Air Force Base. The Stationary Neutron Radiography System utilizes a one megawatt TRIGA reactor contained in an Aluminium tank surrounded by eight foot thick concrete walls. There are four neutron beam tubes at inclined angles from the reactor core to separate radiography bays. In three of the bays, robotic systems manipulate aircraft components in the neutron beam, while real-time imaging systems provide images concurrent with the irradiation. Film radiography of smaller components is performed in the remaining bay

A study of changes in the primary dose penetrating the protective apron on SID in x-ray radiography

International Nuclear Information System (INIS)

Choi, Seong Kwan

2016-01-01

This study is to figure out the amount of primary X-ray generated in SID 50cm, 1m, and 2m penetrating protective aprons in X-ray radiography for hands, skull, and lumbar spine. Results are as follows: Firstly, the exposure dose of primary X-ray which is low such as that of hand X-ray may be reduced by 270 times if protective aprons are worn, but it still slightly penetrates 0.3mm thick Pb protective aprons at SID 50cm, 1m, and 2m. Secondly, the exposure dose of primary X-ray which is moderate such as that of skull X-ray may be reduced by 22 times if protective aprons are worn, but it still fairly penetrates 0.3mm thick Pb protective aprons at SID 50cm, 1m, and 2m. Thirdly, the exposure dose of primary X-ray which is very high such as that of lumbar spine X-ray may be reduced b y 13 times if protective aprons a re worn, but it still penetrates a lot 0.3mm thick Pb protective aprons at SID 50cm, 1m, and 2m. Therefore, people in X-ray room should not only wear protective aprons at any spaces that the primary X-ray can reach, but also need to stand behind the thick Pb shield to protect the body if it is inevitable to stay in the room

A study of changes in the primary dose penetrating the protective apron on SID in x-ray radiography

Energy Technology Data Exchange (ETDEWEB)

Choi, Seong Kwan [Dept. of Radiological Technology, Kwangju Health University, Gwangju (Korea, Republic of)

2016-12-15

This study is to figure out the amount of primary X-ray generated in SID 50cm, 1m, and 2m penetrating protective aprons in X-ray radiography for hands, skull, and lumbar spine. Results are as follows: Firstly, the exposure dose of primary X-ray which is low such as that of hand X-ray may be reduced by 270 times if protective aprons are worn, but it still slightly penetrates 0.3mm thick Pb protective aprons at SID 50cm, 1m, and 2m. Secondly, the exposure dose of primary X-ray which is moderate such as that of skull X-ray may be reduced by 22 times if protective aprons are worn, but it still fairly penetrates 0.3mm thick Pb protective aprons at SID 50cm, 1m, and 2m. Thirdly, the exposure dose of primary X-ray which is very high such as that of lumbar spine X-ray may be reduced b y 13 times if protective aprons a re worn, but it still penetrates a lot 0.3mm thick Pb protective aprons at SID 50cm, 1m, and 2m. Therefore, people in X-ray room should not only wear protective aprons at any spaces that the primary X-ray can reach, but also need to stand behind the thick Pb shield to protect the body if it is inevitable to stay in the room.

A method for describing the doses delivered by transmission x-ray computed tomography

International Nuclear Information System (INIS)

Shope, T.B.; Gagne, R.M.; Johnson, G.C.

1981-01-01

A method for describing the absorbed dose delivered by x-ray transmission computed tomography (CT) is proposed which provides a means to characterize the dose resulting from CT procedures consisting of a series of adjacent scans. The dose descriptor chosen is the average dose at several locations in the imaged volume of the central scan of the series. It is shown that this average dose, as defined, for locations in the central scan of the series can be obtained from the integral of the dose profile perpendicular to the scan plane at these same locations for a single scan. This method for estimating the average dose from a CT procedure has been evaluated as a function of the number of scans in the multiple scan procedure and location in the dosimetry phantom using single scan dose profiles obtained from five different types of CT systems. For the higher dose regions in the phantoms, the multiple scan dose descriptor derived from the single scan dose profiles overestimates the multiple scan average dose by no more than 10%, provided the procedure consists of at least eight scans

Correlation of the clinical and physical image quality in chest radiography for average adults with a computed radiography imaging system.

Science.gov (United States)

Moore, C S; Wood, T J; Beavis, A W; Saunderson, J R

2013-07-01

The purpose of this study was to examine the correlation between the quality of visually graded patient (clinical) chest images and a quantitative assessment of chest phantom (physical) images acquired with a computed radiography (CR) imaging system. The results of a previously published study, in which four experienced image evaluators graded computer-simulated postero-anterior chest images using a visual grading analysis scoring (VGAS) scheme, were used for the clinical image quality measurement. Contrast-to-noise ratio (CNR) and effective dose efficiency (eDE) were used as physical image quality metrics measured in a uniform chest phantom. Although optimal values of these physical metrics for chest radiography were not derived in this work, their correlation with VGAS in images acquired without an antiscatter grid across the diagnostic range of X-ray tube voltages was determined using Pearson's correlation coefficient. Clinical and physical image quality metrics increased with decreasing tube voltage. Statistically significant correlations between VGAS and CNR (R=0.87, pchest CR images acquired without an antiscatter grid. A statistically significant correlation has been found between the clinical and physical image quality in CR chest imaging. The results support the value of using CNR and eDE in the evaluation of quality in clinical thorax radiography.

JRR-3 neutron radiography facility

International Nuclear Information System (INIS)

Matsubayashi, M.; Tsuruno, A.

1992-01-01

JRR-3 neutron radiography facility consists of thermal neutron radiography facility (TNRF) and cold neutron radiography facility (CNRF). TNRF is installed in JRR-3 reactor building. CNRF is installed in the experimental beam hall adjacent to the reactor building. (author)

The Potential Role of Grid-Like Software in Bedside Chest Radiography in Improving Image Quality and Dose Reduction: An Observer Preference Study.

Science.gov (United States)

Ahn, Su Yeon; Chae, Kum Ju; Goo, Jin Mo

2018-01-01

To compare the observer preference of image quality and radiation dose between non-grid, grid-like, and grid images. Each of the 38 patients underwent bedside chest radiography with and without a grid. A grid-like image was generated from a non-grid image using SimGrid software (Samsung Electronics Co. Ltd.) employing deep-learning-based scatter correction technology. Two readers recorded the preference for 10 anatomic landmarks and the overall appearance on a five-point scale for a pair of non-grid and grid-like images, and a pair of grid-like and grid images, respectively, which were randomly presented. The dose area product (DAP) was also recorded. Wilcoxon's rank sum test was used to assess the significance of preference. Both readers preferred grid-like images to non-grid images significantly ( p software significantly improved the image quality of non-grid images to a level comparable to that of grid images with a relatively lower level of radiation exposure.

Glandular dose and image quality control in mammography facilities with computerized radiography systems; Dose glandular e controle de qualidade da imagem em servicos de mamografia com sistema de radiografia computadorizada

Energy Technology Data Exchange (ETDEWEB)

Dantas, Marcelino Vicente de Almeida

2010-07-01

Breast cancer is the most common cancer among women, and early detection is critical to its diagnosis and treatment. To date, the most effective method for early detection of breast cancer has been x-ray mammography for which the screen/film (SF) technique has been the gold standard. However, even though SF combinations have been improved and optimized over the years for breast imaging, there are some critical limitations, including a narrow exposure range, image artifacts, film processing problems, and inflexibility in image processing and film management. In recent years, digital mammography has been introduced in cancer screening programmes with the screen/film techniques gradually being phased out. Computed radiography (CR), also commonly known as photostimulable phosphor (PSP) imaging or storage phosphor, employs reusable imaging plates and associated hardware and software to acquire and to display digital projection radiographs. In this work, a protocol model was tested for performing image quality control and average glandular dose (AGD) evaluation in 19 institutions with computed radiography systems for mammography. The protocol was validated through tests at the Laboratorio de Radioprotecao Aplicada a Mamografia (LARAM) from the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN). The image quality visual evaluation of CDMAM phantom showed that 53% of the facilities were able to produce images of excellent quality. Furthermore, the automated evaluation of image quality, using the analyze software cdcom.exe, showed that 57% of the images were considered to be of good quality. The detector linearity test showed that the CR response is very linear, where 95% of facilities evaluated were considered to be compliant. For the image noise was found that only 20% of facilities are in agreement with the parameters established for this test. The average glandular doses, which patients may be getting to perform an examination, were below the action levels

Neutron radiography at the HFR Petten

International Nuclear Information System (INIS)

Markgraf, J.F.W.

1990-03-01

This report contains the five papers on neutron radiography activities at the Petten High Flux Reactor (HFR) presented at the Third World Conference on Neutron Radiography which was held in May 1989 in Osaka, Japan. In addition, a survey on neutron radiography in Europe for industry and research as presented at the SITEF NDT symposium 1989 on European Advances in Non-Destructive Testing, held in Toulouse/France in October 1989 is included. The papers compiled here are concerned with: the neutron radiography services available in Petten; the experience with and applications of neutron radiography at Petten; image evaluation and analysis techniques at Petten; the practical utilization of nitrocellulose film in neutron radiography in Europe; an introduction into the basic principles of neutron radiography; an overview of the neutron radiography facilities in Europe for industry and research; and a survey of typical applications of neutron radiography in industry, research and sciences. It is the intention of this compilation to provide a comprehensive overview of the present Petten activities and European facilities in this young and promising field of non-destructive testing of materials and components from the nuclear and the non-nuclear industries and research organizations, and from the sciences

Student Incivility in Radiography Education.

Science.gov (United States)

Clark, Kevin R

2017-07-01

To examine student incivility in radiography classrooms by exploring the prevalence of uncivil behaviors along with the classroom management strategies educators use to manage and prevent classroom disruptions. A survey was designed to collect data on the severity and frequency of uncivil student behaviors, classroom management strategies used to address minor and major behavioral issues, and techniques to prevent student incivility. The participants were educators in radiography programs accredited by the Joint Review Committee on Education in Radiologic Technology. Findings indicated that severe uncivil student behaviors in radiography classrooms do not occur as often as behaviors classified as less severe. Radiography educators in this study used a variety of strategies and techniques to manage and prevent student incivility; however, radiography educators who received formal training in classroom management reported fewer incidents of student incivility than those who had not received formal training. The participants in this study took a proactive approach to addressing severe behavioral issues in the classroom. Many radiography educators transition from the clinical environment to the classroom setting with little to no formal training in classroom management. Radiography educators are encouraged to attend formal training sessions to learn how to manage the higher education classroom effectively. Student incivility is present in radiography classrooms. This study provides a foundation for future research on incivility. ©2017 American Society of Radiologic Technologists.

Diagnostic radiography dose and guidance levels

International Nuclear Information System (INIS)

Cuadros, M.; Augusto, A.

2001-01-01

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

Neutron radiography

International Nuclear Information System (INIS)

Alaa eldin, M.T.

2011-01-01

The digital processing of the neutron radiography images gives the possibility for data quantification. In this case an exact relation between the measured neutron attenuation and the real macroscopic attenuation coefficient for every point of the sample is required. The assumption that the attenuation of the neutron beam through the sample is exponential is valid only in an ideal case where a monochromatic beam, non scattering sample and non background contribution are assumed. In the real case these conditions are not fulfilled and in dependence on the sample material we have more or less deviation from the exponential attenuation law. Because of the high scattering cross-sections of hydrogen (σs=80.26 barn) for thermal neutrons, the problem with the scattered neutrons at quantitative radiography investigations of hydrogenous materials (as PE, Oil, H 2 O, etc) is not trivial. For these strong scattering materials the neutron beam attenuation is no longer exponential and a dependence of the macroscopic attenuation coefficient on the material thickness and on the distance between the sample and the detector appears. When quantitative radiography (2 D) or tomography investigations (3 D) are performed, some image correction procedures for a description of the scattering effect are required. This thesis presents a method that can be used to enhance the neutron radiography image for objects with high scattering materials like hydrogen, carbon and other light materials. This method uses the Monte Carlo code, MCNP5, to simulate the neutron radiography process and get the flux distribution for each pixel of the image and determine the scattered neutrons distribution that causes the image blur and then subtract it from the initial image to improve its quality.

SisRadiologia: a new software tool for analysis of radiological accidents and incidents in industrial radiography

International Nuclear Information System (INIS)

Lima, Camila M. Araujo; Silva, Francisco C.A. da; Araujo, Rilton A.

2013-01-01

According to the International Atomic Energy Agency (IAEA), many efforts have been made by Member states, aiming a better control of radioactive sources. Accidents mostly happened in practices named as high radiological risk and classified by IAEA in categories 1 and 2, being highlighted those related to radiotherapy, large irradiators and industrial radiography. Worldwide, more than 40 radiological accidents have been recorded in the industrial radiography. Worldwide, more than 40 radiological accidents have been recorded in the industrial radiography area, involving 37 workers, 110 members of the public and 12 fatalities. Records display 5 severe radiological accidents in industrial radiography activities in Brazil, in which 7 workers and 19 members of the public were involved. Such events led to hands and fingers radiodermatitis, but to no death occurrence. The purpose of this study is to present a computational program that allows the data acquisition and recording in the company, in such a way to ease a further detailed analysis of radiological event, besides providing the learning cornerstones aiming the avoidance of future occurrences. After one year of the 'Industrial SisRadiologia' computational program application - and mostly based upon the workshop about Analysis and Dose Calculation of Radiological Accidents in Industrial Radiography (Workshop sobre Analise e Calculo de dose de acidentes Radiologicos em Radiografia Industrial - IRD 2012), in which several Radiation Protection officers took part - it can be concluded that the computational program is a powerful tool to data acquisition, as well as, to accidents and incidents events recording and surveying in Industrial Radiography. The program proved to be efficient in the report elaboration to the Brazilian Regulatory Authority, and very useful in workers training to fix the lessons learned from radiological events.

Neutron radiography

International Nuclear Information System (INIS)

Hiraoka, Eiichi

1988-01-01

The thermal neutron absorption coefficient is essentially different from the X-ray absorption coefficient. Each substance has a characteristic absorption coefficient regardless of its density. Neutron deams have the following features: (1) neutrons are not transmitted efficiently by low molecular weight substances, (2) they are transmitted efficiently by heavy metals, and (3) the transmittance differs among isotopes. Thus, neutron beams are suitable for cheking for foreign matters in heavy metals and testing of composites consisting of both heavy and light materials. A neutron source generates fast neutrons, which should be converted into thermal neutrons by reducing their energy. Major neutron souces include nuclear reactors, radioisotopes and particle accelerators. Photographic films and television systems are mainly used to observe neutron transmission images. Computers are employed for image processing, computerized tomography and three-dimensional analysis. The major applications of neutron radiography include inspection of neclear fuel; evaluation of material for airplane; observation of fuel in the engine and oil in the hydraulic systems in airplanes; testing of composite materials; etc. (Nogami, K.)

Radiological safety aspects of industrial radiography

International Nuclear Information System (INIS)

Hanekom, A.P.

1983-01-01

Industrial radiography and especially gamma-radiography, has established itself as a very powerful tool in non-destructive testing. Unfortunately there is an amount of risk attached to the use of industrial radiography. The primary causes of radiography accidents include: working conditions, equipment failure and lack of supervisory control. To alleviate the radiological risks involved with gamma-radiography, the Atomic Energy Corporation (AEC) has imposed various conditions for the possession, use, and conveyance of radioactive material. This includes personnel training and equipment specifications

Impact of digitalization of mammographic units on average glandular doses in the Flemish Breast Cancer Screening Program

OpenAIRE

De Hauwere, An; Thierens, Hubert

2012-01-01

The impact of digitalization on the average glandular doses in 49 mammographic units participating in the Flemish Breast Cancer Screening Program was studied. Screen-film was changed to direct digital radiography and computed radiography in 25 and 24 departments respectively. Average glandular doses were calculated before and after digitalization for different PMMA-phantom thicknesses and for groups of 50 successive patients. For the transition from screen-film to computed radiography both ph...

Neutron radiography

International Nuclear Information System (INIS)

Bayon, G.

1989-01-01

Neutronography or neutron radiography, a non-destructive test method which is similar in its principle to conventional X-ray photography, presently occupies a marginal position among non-destructive test methods (NDT) (no source of suitable performance or cost). Neutron radiography associated with the ORPHEE reactor permits industrial testing; it can very quickly meet a cost requirement comparable to that of conventional test methods. In 1988, 2500 parts were tested on this unit [fr

Radiation dose reduction in digital plain radiography of the knee after total knee arthroplasty; Dosisreduktion in der digitalen Radiografie des Kniegelenkes nach endoprothetischem Gelenkersatz

Energy Technology Data Exchange (ETDEWEB)

Kloth, J.K.; Kauczor, H.U.; Weber, M.A. [University Hospital Heidelberg (Germany). Clinic for Diagnostic and Interventional Radiology; Tanner, M.; Ewerbeck, V. [University Hospital Heidelberg (Germany). Center of Orthopedics, Trauma and Spinal Cord Injury; Stiller, W. [German Cancer Research Center (DKFZ), Radiology (E010), Heidelberg (Germany); Burkholder, I. [Univ. of Applied Sciences of the Saarland, Dept. of Nursing and Health, Saarbruecken (Germany)

2015-08-15

To reduce radiation exposure of frequently performed radiographs of the knee in follow-up of total-knee arthroplasty ensuring accurate assessment by using objective quality control criteria. In this prospective randomized study 278 radiographs of the knee in follow-up of total-knee arthroplasty were performed with standard and 37 % reduced radiation dose. The evaluation of the plain-radiographs was conducted using the following criteria: bone-implant interface, implant-surface character, implant-implant discrimination and periarticular heterotopic ossification. Two radiologists evaluated these criteria using a score ranging from 1 (definitely assessable) to 4 (not assessable). If a single criterion had been evaluated with a score ≥ 3 or more than 2 criteria with ≥ 2 points, the radiograph was score das ''not assessable''. The study was designed as non-inferiority-trial. 100 % of examined radiographs were scored as assessable, hence no statistical inferiority between the examinations with standard and reduced dose could be observed. Singular assessment of the defined criteria was likewise dose-independent. Plain-radiography of the knee following total-knee arthroplasty can be performed with 63 % of standard dose without loss of diagnostic validity.

Dosimetry and image quality assessment in a direct radiography system

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Bruno Beraldo; Paixao, Lucas; Nogueira, Maria do Socorro, E-mail: boliveira.mg@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Oliveira, Marcio Alves de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Fac. de Medicina. Dept. de Anatomia e Imagem; Teixeira, Maria Helena Araujo [Clinica Dra. Maria Helena Araujo Teixeira, Belo Horizonte, MG (Brazil)

2014-11-15

Objective: to evaluate the mean glandular dose with a solid state detector and the image quality in a direct radiography system, utilizing phantoms. Materials and methods: Irradiations were performed with automatic exposure control and polymethyl methacrylate slabs with different thicknesses to calculate glandular dose values. The image quality was evaluated by means of the structures visualized on the images of the phantoms. Results: considering the uncertainty of the measurements, the mean glandular dose results are in agreement with the values provided by the equipment and with internationally adopted reference levels. Results obtained from images of the phantoms were in agreement with the reference values. Conclusion: the present study contributes to verify the equipment conformity as regards dose values and image quality. (author)

Heavy-ion radiography

International Nuclear Information System (INIS)

Fabrikant, J.I.; Tobias, C.A.; Holley, W.R.; Benton, E.V.; Woodruff, K.H.; MacFarland, E.W.

1983-01-01

High energy, heavy-ion beams offer superior discrimination of tissue electron densities at very low radiation doses. This characteristic has potential for diagnostic medical imaging of neoplasms arising in the soft tissues and organs because it can detect smaller inhomogeneities than x rays. Heavy-ion imaging may also increase the accuracy of cancer radiotherapy planning involving use of accelerated charged particles. In the current physics research program of passive heavy-ion imaging, critical modulation transfer function tests are being carried out in heavy-ion projection radiography and heavy-ion computerized tomography. The research goal is to improve the heavy-ion imaging method until it reaches the limits of its theoretical resolution defined by range straggling, multiple scattering, and other factors involved in the beam quality characteristics. Clinical uses of the imaging method include the application of heavy-ion computerized tomography to heavy-ion radiotherapy planning, to the study of brain tumors and other structures of the head, and to low-dose heavy-ion projection mammography, particularly for women with dense breasts where other methods of diagnosis fail. The ions used are primarily 300 to 570 MeV/amu carbon and neon ions accelerated at the Lawrence Berkeley Laboratory Bevalac

Method and apparatus for shadow aperture backscatter radiography (SABR) system and protocol

Science.gov (United States)

Shedlock, Daniel (Inventor); Jacobs, Alan M. (Inventor); Jacobs, Sharon Auerback (Inventor); Dugan, Edward (Inventor)

2010-01-01

A shadow aperture backscatter radiography (SABR) system includes at least one penetrating radiation source for providing a penetrating radiation field, and at least one partially transmissive radiation detector, wherein the partially transmissive radiation detector is interposed between an object region to be interrogated and the radiation source. The partially transmissive radiation detector transmits a portion of the illumination radiation field. A shadow aperture having a plurality of radiation attenuating regions having apertures therebetween is disposed between the radiation source and the detector. The apertures provide illumination regions for the illumination radiation field to reach the object region, wherein backscattered radiation from the object is detected and generates an image by the detector in regions of the detector that are shadowed by the radiation attenuation regions.

X-ray vector radiography for bone micro-architecture diagnostics

Energy Technology Data Exchange (ETDEWEB)

Malecki, Andreas; Potdevin, Guillaume; Biernath, Thomas; Bech, Martin; Pfeiffer, Franz [Department of Physics and Institute of Medical Engineering, Technische Universitaet Muenchen, 85748 Garching (Germany)

2012-07-01

The non-invasive estimation of fracture risk in osteoporosis remains a challenge in the clinical routine and is mainly based on an assessment of bone density by dual X-ray absorption (DXA). Although bone micro-architecture is known to play an important role for bone fragility, its visualisation implies an imaging resolution better than 100 {mu}m, which limits the field of view and increases the necessary radiation dose. Here we describe a new method, X-ray Vector Radiography (XVR), based on X-ray scattering rather than absorption as contrast source, which yields information about the local orientation and degree of anisotropy of the bone micro-structure. This information is highly relevant for osteoporosis diagnostic. We demonstrate the feasibility by showing first experimental X-ray Vector Radiographies of human vertebra bone samples, yielding information on the trabecular structure.

Computer-aided diagnosis of pulmonary diseases using x-ray darkfield radiography

DEFF Research Database (Denmark)

Einarsdottir, Hildur; Yaroshenko, Andre; Velroyen, Astrid

2015-01-01

In this work we develop a computer-aided diagnosis (CAD) scheme for classification of pulmonary disease for grating-based x-ray radiography. In addition to conventional transmission radiography, the grating-based technique provides a dark-field imaging modality, which utilizes the scattering...... properties of the x-rays. This modality has shown great potential for diagnosing early stage emphysema and fibrosis in mouse lungs in vivo. The CAD scheme is developed to assist radiologists and other medical experts to develop new diagnostic methods when evaluating grating-based images. The scheme consists...... of three stages: (i) automatic lung segmentation; (ii) feature extraction from lung shape and dark-field image intensities; (iii) classification between healthy, emphysema and fibrosis lungs. A study of 102 mice was conducted with 34 healthy, 52 emphysema and 16 fibrosis subjects. Each image was manually...

Validation of Computed Radiography (CR) Exposure Chart for Stainless Steel and Aluminium

International Nuclear Information System (INIS)

Nassir, M.A.; Khairul Anuar Mohd Salleh; Arshad Yassin

2015-01-01

Computed radiography (CR) is a technique that is currently used to complement the conventional radiography in Non Destructive Testing (NDT). With CR, phosphorous base imaging plate (IP) is used to acquire digital radiographic images. The degree of absorption by the IP is proportional to the intensity of the dose received. The IP stores latent image which subsequently digitized by the CR reader. Prior to radiography exposure, the radiation dosage is determined by referring to the exposure chart. Exposure chart is one of the most important tools for achieving acceptable quality radiographs. Therefore, it is important to have a reliable and accurate exposure chart. The aim of this study is to test and validate exposure charts that were developed based on the statistical analysis of the digital radiographic grey values. The charts produced were for stainless steel and aluminum. According to EN 14784-2:2005, acceptable normalized signal-to-noise ratio (SNR N ) for testing class A and class B shall have minimum 70 and 120 respectively. (author)

Radiography with polarised neutrons

Energy Technology Data Exchange (ETDEWEB)

Schulz, Michael L.

2010-08-20

In this thesis I present a new technique for the spatially resolved investigation of the magnetic properties of bulk samples. Standard one dimensional neutron depolarisation analysis is combined with neutron radiography to a method we call Neutron Depolarisation Imaging (NDI). The experimental setup which was installed at the neutron radiography beam line ANTARES at FRM II consists of a double crystal monochromator, neutron polariser, spin flipper, polarisation analyser and a position sensitive CCD detector. A comprehensive discussion of the requirements for these components is given and the limitations of the method are shown. The maximum spatial resolution which can be achieved with a neutron radiography setup is determined by the collimation of the neutron beam and the distance between sample and detector. Different types of polarisers have been tested and their advantages and disadvantages are discussed. A double crystal monochromator and a new type of polariser employing polarising neutron supermirrors based on the principle of an optical periscope were developed and tested during this work. Furthermore, NDI measurements on various samples of the weakly ferromagnetic materials Pd{sub 1-x}Ni{sub x} and Ni{sub 3}Al are presented. Neutron depolarisation radiography and tomography measurements were conducted with a spatial resolution as high as 0.3 mm on Pd{sub 1-x}Ni{sub x} and Ni{sub 3}Al samples. The feasibility of NDI experiments under hydrostatic pressures up to 10 kbar was shown on a sample of Ni{sub 3}Al using a modified Cu:Be clamp cell. A decrease of the ordering temperature by 2 K under hydrostatic pressure was determined from the NDI measurements and shows the potential of the method for further high pressure experiments. Additionally a method was developed which in principle allows to obtain the intrinsic dependence of the ordering temperature T{sub C} on the ordered moment Ms from NDI measurements on inhomogeneous samples containing regions with

Changes in patient exposure doses from diagnostic radiological procedures in Japan, 1974-2007

International Nuclear Information System (INIS)

Suzuki, Shoichi; Ito, Yusuke; Asada, Yasuki; Hattori, S.; Kamei, S.; Koga, Sukehiko

2008-01-01

We have investigated changes in exposure dose in Japan in terms of the same items since 1974. An assessment was made of changes in exposure dose during a period of 33 years. Nationwide investigation was conducted six times from 1974 to 2007 with regard to 14 target areas (21 kinds of projections). The investigations we examined is as follows: tube voltage (kV), tube current (mA), exposure time (sec), focus surface distance, thickness of total filtration and type of generator system for diagnostic radiography for a typical patient. Entrance surface doses were evaluated in terms of the respective exposure conditions based on basic experiment. The results showed that the exposure doses decreased to less than 50% during a 15-year period till 1994, with the exposure doses in 1974 assumed to be 100%. The exposure doses in 2007 were equivalent to, or increased over the exposure doses in 1994 at some areas. A comparison with the international basic safety standard for protection against ionizing radiation set up by the IAEA, that is, the so-called guidance level, indicated that the exposure doses in 2007 were less than the standard in all areas. The comparison with past investigations also demonstrated that F/S system using film-intensifying screen has been increasingly replaced with computed radiography (CR) system using imaging plates (IP) and flat panel digital radiography (FPD) system. In the investigation in 2007, an attempt was made of a comparison between exposure dose by the digital radiography system and that by the F/S system as well. It was clarified that there was no large difference in the exposure dose between those systems. (author)

Precise natural radiography of seafloor sedimentary cores by using imaging plate

International Nuclear Information System (INIS)

Sugihara, Makoto; Tsuchiya, Noriyoshi

2007-01-01

The radiation measurement for seafloor sedimentary cores was carried out by using the Imaging Plate (IP). The precise natural radiography was obtained with 48 hours (exposure time) in a shield box. Layered structures of seafloor sediments that have relatively low radioactivity like biogenic matters could be detected by autoradiography, and it was possible to identify optically unclear layers of sediments with differences of radiation characteristics. The detection limit of thickness of suspended particle layers like volcanic ashes might be sub millimeters. It was possible to identify the pinpoint position where radioactive mineral emitted α-rays at the surface of sample. Identification of pinpoint position could be possible suppose radioactive minerals that emits α-ray exposed at the surface of sample. Distribution of dose (PSL value of IP) was related to CT value (X-ray CT), which indicates dose of sedimentary core have relationships with density and atomic number of sediments. The natural radiography for seafloor sediments cores by using the Imaging Plate is considered to be a powerful new tool as a non-destructive core analysis. (author)

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

International Nuclear Information System (INIS)

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

2008-01-01

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

Estimate of dose in crystalline and thyroid in exam complete periapical

International Nuclear Information System (INIS)

Bonzoumet, S.P.J.; Braz, D.; Barroso, R.C.; Mauricio, C.L.P.; Domingues, C.; Padilha, L.G.F.

2006-01-01

The constant achievement of dental radiography portrays the necessity of care in this practice for neither patient nor professional subject to a risk of excessive radiation. The main aim of this work is to estimate the crystalline and thyroid absorbed dose, during dental radiography. To evaluate the dose distribution it was used thermoluminescent dosimeter T.L.D.100. The measures were carried out on patients during intra-oral dental radiography in some dental clinics in Rio de Janeiro. Three dental equipments were investigated: Dhabi ATLANTE 1070, DABI ATLANTE 70x and SELETRONIC 70x. Analyzing the doses evaluated, it can be observed that there is a variation in the obtained values for the three points studied and for the three equipments utilized. It was noticed that while using the DABI1070, a larger dose was taken because of the size field diameter to equipment. In the 70x equipment was that one what obtains best results in every points. The results obtained from the SELETRONIC 70x have shown that there is a difference in two techniques used: with the positioner or without it. This achieved values superior than that, because the tip of patient was on display straight to radiation. This study was useful to confirm the excessive dose, besides of not was biased to nothing for the radiography quality,represents a risk for the patient who retains unnecessary and harmful radiation to system. (authors)

Estimate of dose in crystalline and thyroid in exam complete periapical

Energy Technology Data Exchange (ETDEWEB)

Bonzoumet, S.P.J.; Braz, D. [Lab. de Instrumentacao Nuclear, COPPE/UFRJ, CEP, Rio de Janeiro (Brazil); Barroso, R.C. [Rio de Janeiro Univ. do Estado, Instituto de Fisica (Brazil); Mauricio, C.L.P.; Domingues, C. [Instituto de Radioprotecao e Dosimetria IRD / CNEN (Brazil); Padilha, L.G.F. [Rio de Janeiro Univ. Federal, Hospital Universitario (Brazil)

2006-07-01

The constant achievement of dental radiography portrays the necessity of care in this practice for neither patient nor professional subject to a risk of excessive radiation. The main aim of this work is to estimate the crystalline and thyroid absorbed dose, during dental radiography. To evaluate the dose distribution it was used thermoluminescent dosimeter T.L.D.100. The measures were carried out on patients during intra-oral dental radiography in some dental clinics in Rio de Janeiro. Three dental equipments were investigated: Dhabi ATLANTE 1070, DABI ATLANTE 70x and SELETRONIC 70x. Analyzing the doses evaluated, it can be observed that there is a variation in the obtained values for the three points studied and for the three equipments utilized. It was noticed that while using the DABI1070, a larger dose was taken because of the size field diameter to equipment. In the 70x equipment was that one what obtains best results in every points. The results obtained from the SELETRONIC 70x have shown that there is a difference in two techniques used: with the positioner or without it. This achieved values superior than that, because the tip of patient was on display straight to radiation. This study was useful to confirm the excessive dose, besides of not was biased to nothing for the radiography quality,represents a risk for the patient who retains unnecessary and harmful radiation to system. (authors)

Real-time radiography

International Nuclear Information System (INIS)

Bossi, R.H.; Oien, C.T.

1981-01-01

Real-time radiography is used for imaging both dynamic events and static objects. Fluorescent screens play an important role in converting radiation to light, which is then observed directly or intensified and detected. The radiographic parameters for real-time radiography are similar to conventional film radiography with special emphasis on statistics and magnification. Direct-viewing fluoroscopy uses the human eye as a detector of fluorescent screen light or the light from an intensifier. Remote-viewing systems replace the human observer with a television camera. The remote-viewing systems have many advantages over the direct-viewing conditions such as safety, image enhancement, and the capability to produce permanent records. This report reviews real-time imaging system parameters and components

A survey of digital radiography practice in four South African teaching hospitals: an illuminative study.

Science.gov (United States)

Nyathi, T; Chirwa, Tf; van der Merwe, Dg

2010-01-01

The purpose of this study was to assess radiographer familiarity and preferences with digital radiography in four teaching hospitals and thereafter make recommendations in line with the migration from screen film to digital radiography. A questionnaire was designed to collect data from either qualified or student radiographers from four teaching hospitals. From the four teaching hospitals, there were a total of 205 potential respondents. Among other things, responses regarding experiences and preferences with digital radiography, quality control procedures, patient dose, advantages and disadvantages of digital radiography were sought. The information collected was based on self-reporting by the participants. The study is exploratory in nature and descriptive statistics were generated from the collected data using Microsoft Excel 2007 and StatsDirect software. Sixty-three out of 205 (31%) radiographers from all the four radiology centers responded to the circulated questionnaire. Only 15% (8) of the qualified radiographers had 4 or more years of experience with digital radiography compared to 68% (36) for the same amount of experience with screen-film radiography. Sixty-one percent (38) of the participants had been exposed to digital radiography during their lectures while at university. A small proportion, 16% (10) of the respondents underwent formal training in quality control procedures on the digital X-ray units they were using. Slightly more than half (55%) of the participants felt it was easier for them to retake an image in digital radiography than in screen film radiography. The results of this survey showed that the participants are familiar with digital radiography and have embraced this relatively new technology as shown by the fact that they can identify both its advantages and disadvantages as applied to clinical practice. However, there are minimal quality control procedures specific to digital radiography being undertaken as such there is need for

Radiation protection in equine radiography

International Nuclear Information System (INIS)

Wood, A.K.W.; Reynolds, K.M.; Leith, I.S.; Burns, P.A.

1974-01-01

During radiography of the carpus of horses calcium fluoride thermoluminescent dosemeters were used to measure the radiation exposure to the hand of an assistant positioning the x-ray film. Three portable x-ray machines and a mobile machine were used during the recordings. The effects of x-ray machine, radiographic technique, and lead rubber gloves upon radiation exposure to the hand were investigated. The size of the primary beam of the x-ray machine was found to be the major factor in determining the dose of radiation received by the hand. The highest radiation exposures were recorded when using two portable machines which were fitted with beam limiting devices that permitted only one primary beam size. The lowest exposures were measured when radiographs were taken with the mobile machine that was fitted with a light beam diaphragm. The control of primary beam size with a light beam diaphragm was found to be the most effective method of reducing radiation dosage to the hand. It is strongly recommended that for equine radiography a light beam diaphragm be fitted to and used on all x-ray machines, and a cassette holder be used to keep the hands out of the primary beam. (author)

Radiography using californium-252 neutron sources

International Nuclear Information System (INIS)

Ray, J.W.

1975-01-01

The current status in the technology of neutron radiography using californium-252 neutron sources is summarized. Major emphasis is on thermal neutron radiography since it has the widest potential applicability at the present time. Attention is given to four major factors which affect the quality and useability of thermal neutron radiography: source neutron thermalization, neutron beam extraction geometry, neutron collimator dimensions, and neutron imaging methods. Each of these factors has a major effect on the quality of the radiographs which are obtained from a californium source neutron radiography system and the exposure times required to obtain the radiographs; radiograph quality and exposure time in turn affect the practicality of neutron radiography for specific nondestructive inspection applications. A brief discussion of fast neutron radiography using californium-252 neutron sources is also included. (U.S.)

Double beam neutron radiography facility

International Nuclear Information System (INIS)

Domanus, J.C.

1977-09-01

The DR1 reactor at Risoe is used as a neutron source for neutron radiography. In the double-beam neutron radiography facility a neutron flux of an intensity of 1.4 and 1.8 x 10 6 n. cm -2 . s -1 reaches the object to be radiographed. The transport and exposure container used for neutron radiography of irradiated nuclear fuel rods is described, and the exposure technique and procedure are reviewed. The mode by which single neutron radiographs are assembled and assessed is described. This report will be published in the ''Neutron Radiography Newsletter''. (author)

Tomosynthesis of the wrist and hand in patients with rheumatoid arthritis: comparison with radiography and MRI.

Science.gov (United States)

Aoki, Takatoshi; Fujii, Masami; Yamashita, Yoshiko; Takahashi, Hiroyuki; Oki, Hodaka; Hayashida, Yoshiko; Saito, Kazuyoshi; Tanaka, Yoshiya; Korogi, Yukunori

2014-02-01

The purpose of this article is to compare tomosynthesis with radiography and MRI of the wrist and hand for evaluating bone erosion in patients with rheumatoid arthritis (RA). Twenty consecutive patients with an established diagnosis of RA and five control patients were included in this study. They underwent radiography, tomosynthesis, and MRI of the bilateral hand and wrist within a week. The mean total dose of radiography and tomosynthesis was 0.13 and 0.25 mGy, respectively. MRI evaluation was performed according to the Outcome Measures in Rheumatology Clinical Trials recommendations. Bone erosion on images from the three modalities was independently reviewed by two certificated radiologists with a 4-point scale (0, normal; 1, discrete erosion; 2, tomosynthesis, and MRI were 26.5%, 36.1%, and 36.7%, respectively. Significantly more bone erosions were revealed with tomosynthesis and MRI than with radiography (p tomosynthesis. Interobserver agreement (kappa value) for bone erosion was good to excellent on tomosynthesis and MRI for all joints (0.65-1.00 and 0.68-1.00, respectively), whereas it was slight to fair on radiography for some carpal bones and bases of metacarpal bones (0.22-0.56). Tomosynthesis is superior to radiography and almost comparable to MRI for the detection of bone erosion in patients with RA.

Magnification radiography

International Nuclear Information System (INIS)

Genant, H.K.; Resnick, D.

1988-01-01

The relative clinical value of magnification compared with conventional radiography for skeletal applications is presented qualitatively. The presentation is based on the authors' experience with over 25,000 cases in which magnification has been used. For most areas in which magnification (optical or geometric) proves useful, subtle abnormalities of clinical importance are present at bone surfaces or at host-lesion interfaces. This is particularly true for arthritis and metabolic and infectious disorders of bone. In additional instances, serial assessment of the progression of disease or its response to therapy is enhanced by magnification. When gross abnormalities are present, as in most instances of trauma and bone dysplasia, the findings are obvious on conventional radiography, and magnification is not necessary. Thus, the magnification techniques appear to provide important diagnostic information, depending upon the anatomic part that is studied and the clinical question that is posed. It is also apparent that the demonstration of subtle skeletal abnormalities to clinical colleagues for educational purposes is greatly enhanced by magnification radiography

Assessment of the Main Deviations Found during Regulatory Inspections in Industrial Gamma Radiography in Argentina

International Nuclear Information System (INIS)

Alonso Jimenez, M.T.; Ermacora, M.G.

2011-01-01

The present paper shows the regulatory work made through inspections concerning radiation safety and security in the area of industrial gamma radiography. An account is shown of the items which should be available in the storage facility where the equipment and radioactive sources are placed as well as in site radiography and which are required to the users of the equipment meant for this practice, in order to ensure compliance with the regulations in force. The objective of this paper is to assess the most frequent deviations to the regulatory standards found during this type of inspections, such as lack of complete and operable radiation protection equipment, lack of available elements bound to act in case of emergency, no delimitation of controlled areas, gamma radiography equipment stored in unlocked position, wear gauge unavailable, record of movements of equipment and radioactive sources not updated, anomalous monthly or annual personal dose values, among the main findings. In particular, in connection with dose reports, some cases of occupational exposed workers exceeding the annual dose limits or investigation levels are highlighted. In addition, the explanations provided by the person responsible for radiation protection of companies in regard to the possible causes or circumstances which might have given rise to such dose values, the conclusions reached and the preventive and corrective measures implemented by these companies are analysed. Finally, an assessment of the annual dose distributions of the occupational exposed workers concerned with this kind of practice in the period 2004-2007 is shown. As a conclusion, the relevance of these deviations according to degradation in safety and security performance and the role of the regulatory work as a promoter of the implementation of safety culture will be emphasized. (authors)

Assessment of the main deviations found during regulatory inspections in industrial gamma radiography in Argentina

International Nuclear Information System (INIS)

Alonso Jimenez, Maria T.; Ermacora, Marcela

2008-01-01

The present paper shows the regulatory work made through inspections concerning radiation safety and security in the area of industrial gamma radiography. An account is shown of the items which should be available in the storage facility where the equipment and radioactive sources are placed as well as in site radiography and which are required to the users of the equipment meant for this practice, in order to ensure compliance with the regulations in force. The objective of this paper is to assess the most frequent deviations to the regulatory standards found during this type of inspections, such as lack of complete and operable radiation protection equipment, lack of available elements bound to act in case of emergency, no delimitation of controlled areas, gamma radiography equipment stored in unlocked position, wear gauge unavailable, record of movements of equipment and radioactive sources not updated, anomalous monthly or annual personal dose values, among the main findings. In particular, in connection with dose reports, some cases of occupational exposed workers exceeding the annual dose limits or investigation levels are highlighted. In addition, the explanations provided by the person responsible for radiation protection of companies in regard to the possible causes or circumstances which might have given rise to such dose values, the conclusions reached and the preventive and corrective measures implemented by these companies are analysed. Finally, an assessment of the annual dose distributions of the occupational exposed workers concerned with this kind of practice in the period 2004-2007 is shown. As a conclusion, the relevance of these deviations according to degradation in safety and security performance and the role of the regulatory work as a promoter of the implementation of safety culture will be emphasized. (author)

Bone X-Ray (Radiography)

Medline Plus

Full Text Available ... are the limitations of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray ( ... leg (shin), ankle or foot. top of page What are some common uses of the procedure? A ...

Comparison of two dose and three dose human papillomavirus vaccine schedules: cost effectiveness analysis based on transmission model.

Science.gov (United States)

Jit, Mark; Brisson, Marc; Laprise, Jean-François; Choi, Yoon Hong

2015-01-06

To investigate the incremental cost effectiveness of two dose human papillomavirus vaccination and of additionally giving a third dose. Cost effectiveness study based on a transmission dynamic model of human papillomavirus vaccination. Two dose schedules for bivalent or quadrivalent human papillomavirus vaccines were assumed to provide 10, 20, or 30 years' vaccine type protection and cross protection or lifelong vaccine type protection without cross protection. Three dose schedules were assumed to give lifelong vaccine type and cross protection. United Kingdom. Males and females aged 12-74 years. No, two, or three doses of human papillomavirus vaccine given routinely to 12 year old girls, with an initial catch-up campaign to 18 years. Costs (from the healthcare provider's perspective), health related utilities, and incremental cost effectiveness ratios. Giving at least two doses of vaccine seems to be highly cost effective across the entire range of scenarios considered at the quadrivalent vaccine list price of £86.50 (€109.23; $136.00) per dose. If two doses give only 10 years' protection but adding a third dose extends this to lifetime protection, then the third dose also seems to be cost effective at £86.50 per dose (median incremental cost effectiveness ratio £17,000, interquartile range £11,700-£25,800). If two doses protect for more than 20 years, then the third dose will have to be priced substantially lower (median threshold price £31, interquartile range £28-£35) to be cost effective. Results are similar for a bivalent vaccine priced at £80.50 per dose and when the same scenarios are explored by parameterising a Canadian model (HPV-ADVISE) with economic data from the United Kingdom. Two dose human papillomavirus vaccine schedules are likely to be the most cost effective option provided protection lasts for at least 20 years. As the precise duration of two dose schedules may not be known for decades, cohorts given two doses should be closely

Transitioning to digital radiography

Energy Technology Data Exchange (ETDEWEB)

Miranda, F., E-mail: Francisco.Miranda@pwc.ca [Pratt & Whitney Canada, Longueuil, Quebec (Canada)

2015-09-15

This article provides insight on the technical and business considerations necessary to implement or to transition to digital radiography Continued refinements in digital radiography technology have resulted in significant improvements in image quality and detectability of indications. These improvements have resulted in the acceptance of the technology by users and aerospace primes for final product inspection and disposition. Digital radiography has also been identified as an interesting cost reduction initiative with the potential of providing gains in productivity through increased throughput and decreased inspection lead-times and resulting costs. (author)

Recent developments in radiography

International Nuclear Information System (INIS)

Berger, Harold

1982-01-01

Advances in radiography are reviewed and eighty-one references are cited to provide additional information. The review includes information on x-ray sources in terms of output, portability and imaging geometry and detectors in terms of films and screens, electrostatic methods, real-time techniques and solid state devices. Inspection methods utilizing radiations other than x-rays, neutrons and charged particles, expand the inspection problems suitable for radiography. Techniques such as tomography, digital radiography and image enhancement are described. Tomography, in particular, provides excellent capability to characterize materials and discontinuities

Radiation doses from dental radiography at private practioneers

Energy Technology Data Exchange (ETDEWEB)

Hylthen, J A

1975-10-01

This investigation was made in January 1975 together with a seminar group from the faculty of odontology in Stockholm. Every four private practising dentists in Stockholm and its environs were selected by haphazard to get an enquiry equipment etc. Every forty private practising dentists were then selected by haphazard to get a visit. 32 x-ray plants were investigated. The radiation doses showed a great spreading. The mean value of the radiation doses to the irradiated organs had been reduced about 5 times compared to a similar investigation, which was made in 1960. The use of long metal tubes and high-speed film gave the lowest dose values, while a short cone of bakelite and a low-speed film gave the highest dose values. Fluctuations in the dose values seemed also to depend on the technique. The reasons for this may be variations in the settings of the instruments and in the dark room technique.

neutron radiography. Report prepared from contributions by members of the MOD Working Party on Neutron Radiography

International Nuclear Information System (INIS)

Halmshaw, R.

1977-03-01

Radiography with thermal or cold neutrons has some special advantages over X-rays and gamma rays, and some facilities for neutron radiography exist in the Ministry of Defence. This report gives a brief and simple description of the technique, its advantages and disadvantages, and is illustrated with a number of Ordnance applications taken from MOD work, to show examples where neutron radiographs provided extra important information not available from X- or gamma radiography. The facilities available in the UK for neutron radiography are listed. (author)

Occupational dose constraint

International Nuclear Information System (INIS)

Heilbron Filho, Paulo Fernando Lavalle; Xavier, Ana Maria

2005-01-01

The revision process of the international radiological protection regulations has resulted in the adoption of new concepts, such as practice, intervention, avoidable and restriction of dose (dose constraint). The latter deserving of special mention since it may involve reducing a priori of the dose limits established both for the public and to individuals occupationally exposed, values that can be further reduced, depending on the application of the principle of optimization. This article aims to present, with clarity, from the criteria adopted to define dose constraint values to the public, a methodology to establish the dose constraint values for occupationally exposed individuals, as well as an example of the application of this methodology to the practice of industrial radiography

Selenium-based digital radiography of the cervical spine. Comparison with screen-film radiography for the depiction of anatomic details

International Nuclear Information System (INIS)

Ludwig, K.; Diederich, S.; Wormanns, D.; Link, T.M.; Lenzen, H.; Heindel, W.

2002-01-01

Purpose: To compare selenium-based digital radiography with conventional screen-film radiography of the cervical spine. Materials and Methods: In a prospective study X-ray images of the cervical spine were obtained in 25 patients using selenium-based digital radiography and conventional screen-film radiography. All images were clinically indicated. Selenium-based digital radiography and conventional screen-film radiography were used in a randomized order. Four radiologists independently evaluated all 50 examinations for the visibility of 76 anatomic details according to a five-level confidence scale (1=not visible, 5=very good visibility). From the evaluation of these anatomic details scores for the upper and middle cervical spine, the cervicothoracic junction and the cervical soft tissues were calculated. The scores for selenium-based digital radiography and conventional screen-film radiography were compared using Wilcoxon's signed rank test. Results: From a total of 15,200 observations (608 per patient) the following scores were calculated for selenium-based digital radiography and for screen-film radiography, respectively: Upper cervical spine 3.88 and 3.94; middle cervical spine 4.60 and 4.48; cervico-thoracic junction 3.64 and 2.62; cervical soft tissue 4.47 and 3.46. The differences between the last two scores were statistically significant (p [de

Leaded apron for use in panoramic dental radiography

Energy Technology Data Exchange (ETDEWEB)

Whitcher, B.L.; Gratt, B.M.; Sickles, E.A.

1980-05-01

The leaded aprons currently available for use during dental radiography do not protect the thyroid gland from radiation. Conventional aprons may produce artifacts when used with panoramic dental x-ray units. This study measures the dose reduction obtained with an experimental leaded apron designed for use with panoramic dental x-ray units. Skin exposures measured at the thyroid and at the sternum were reduced with the use of the apron. Films produced during the study were free from apron artifacts.

Leaded apron for use in panoramic dental radiography

International Nuclear Information System (INIS)

Whitcher, B.L.; Gratt, B.M.; Sickles, E.A.

1980-01-01

The leaded aprons currently available for use during dental radiography do not protect the thyroid gland from radiation. Conventional aprons may produce artifacts when used with panoramic dental x-ray units. This study measures the dose reduction obtained with an experimental leaded apron designed for use with panoramic dental x-ray units. Skin exposures measured at the thyroid and at the sternum were reduced with the use of the apron. Films produced during the study were free from apron artifacts

Radioisotopes - their applications in industrial radiography

International Nuclear Information System (INIS)

Rao, H.R.S.

1977-01-01

The nature of radioisotopes and their industrial applications with special reference to industrial radiography are outlined. The various aspects of industrial radiography such as source size, source containers, films, density of radiography, radiographic quality and applications are discussed in brief. (M.G.B.)

Incident in industrial gamma radiography in Argentina

International Nuclear Information System (INIS)

Alonso Jimenez, Maria T.; Ermacora, Marcela

2008-01-01

In the present work a description of an industrial gamma radiography incident is made and an analysis of the events which led to it is presented. The event took place during a routine regulatory inspection carried out by personnel of the Nuclear Regulatory Authority in the year 2004 to a storage facility of projectors and containers belonging to a company licensed to operate gamma radiography equipment. On arriving to the store authorized by the ARN, placed in an industrial site, it was verified that it was empty and without surveillance. The inspectors contacted the person responsible for radiological protection, who went to the place and declared that the totality of the equipment and radioactive sources had been moved to a private country house. The reason for this change, according to the statement, was that the company had gone bankrupt and the authorized storage facility had remained without surveillance and without personnel in charge. In the country house, inside the room meant as a store, high environmental equivalent dose rates were detected. After verifying the dose rates in each of the projectors, it was checked that one of them measured high dose rates. For this reason, it was isolated and the source recovery was done, due to the suspicion that it had remained in a non-shielded position. After projecting it several times towards a lead container due to the fact that high dose rates were still being measured, the person responsible for radiological protection proceeded to extract the source from the guide tube, finding that it had been transferred in the reverse order. According to the record of movements of equipment and radioactive sources of the company, the source transference had been done, in the previous store in the month of March 2004, by a radiographer who did not work at the company any longer and whose permit had expired. The results of the estimations of the doses received during the process of the source recovery are presented. Finally, an

An epidemiological study on patient exposure from dental radiography

International Nuclear Information System (INIS)

Ehara, Masahiro

1980-01-01

The gonadal and bone marrow doses received by patients per exposure from dental X-ray examinations are small when compared to those of other medical X-ray procedures. Therefore, the contribution from dental X-ray exposure dose has not been discussed in terms of individual dose, but has always been considered in terms of population dose. However, depending on the peculiarity of the disease involved, some dental patients are considered to be subjected to relatively large doses of diagnostic X-rays. Therefore, from the standpoint of overall radiation protection, it was felt important to estimate the maximum individual dose incurred by diagnostic dental radiography. An epidemiological survey was undertaken at Osaka Dental University Hospital to estimate the maximum radiation exposure doses to various organs by projection. A total of 1301 patients were randomly selected from among persons who had initially visited the Radiology Department and subsequently received many X-ray exposures. The individual exposure dose to each organ was determined by projection based on the type and number of examinations. Results showed that the conditions incurring the maximum exposure dose in individual patients for diagnostic purposes in the dental region was those with ameloblastoma. (author)

SU-E-T-602: Patient-Specific Online Dose Verification Based On Transmission Detector Measurements

Energy Technology Data Exchange (ETDEWEB)

Thoelking, J; Yuvaraj, S; Jens, F; Lohr, F; Wenz, F; Wertz, H; Wertz, H [University Medical Center Mannheim, University of Heidelberg, Mannheim, Baden-Wuerttemberg (Germany)

2015-06-15

Purpose: Intensity modulated radiotherapy requires a comprehensive quality assurance program in general and ideally independent verification of dose delivery. Since conventional 2D detector arrays allow only pre-treatment verification, there is a debate concerning the need of online dose verification. This study presents the clinical performance, including dosimetric plan verification in 2D as well as in 3D and the error detection abilities of a new transmission detector (TD) for online dose verification of 6MV photon beam. Methods: To validate the dosimetric performance of the new device, dose reconstruction based on TD measurements were compared to a conventional pre-treatment verification method (reference) and treatment planning system (TPS) for 18 IMRT and VMAT treatment plans. Furthermore, dose reconstruction inside the patient based on TD read-out was evaluated by comparing various dose volume indices and 3D gamma evaluations against independent dose computation and TPS. To investigate the sensitivity of the new device, different types of systematic and random errors for leaf positions and linac output were introduced in IMRT treatment sequences. Results: The 2D gamma index evaluation of transmission detector based dose reconstruction showed an excellent agreement for all IMRT and VMAT plans compared to reference measurements (99.3±1.2)% and TPS (99.1±0.7)%. Good agreement was also obtained for 3D dose reconstruction based on TD read-out compared to dose computation (mean gamma value of PTV = 0.27±0.04). Only a minimal dose underestimation within the target volume was observed when analyzing DVH indices (<1%). Positional errors in leaf banks larger than 1mm and errors in linac output larger than 2% could clearly identified with the TD. Conclusion: Since 2D and 3D evaluations for all IMRT and VMAT treatment plans were in excellent agreement with reference measurements and dose computation, the new TD is suitable to qualify for routine treatment plan

SU-E-T-602: Patient-Specific Online Dose Verification Based On Transmission Detector Measurements

International Nuclear Information System (INIS)

Thoelking, J; Yuvaraj, S; Jens, F; Lohr, F; Wenz, F; Wertz, H; Wertz, H

2015-01-01

Purpose: Intensity modulated radiotherapy requires a comprehensive quality assurance program in general and ideally independent verification of dose delivery. Since conventional 2D detector arrays allow only pre-treatment verification, there is a debate concerning the need of online dose verification. This study presents the clinical performance, including dosimetric plan verification in 2D as well as in 3D and the error detection abilities of a new transmission detector (TD) for online dose verification of 6MV photon beam. Methods: To validate the dosimetric performance of the new device, dose reconstruction based on TD measurements were compared to a conventional pre-treatment verification method (reference) and treatment planning system (TPS) for 18 IMRT and VMAT treatment plans. Furthermore, dose reconstruction inside the patient based on TD read-out was evaluated by comparing various dose volume indices and 3D gamma evaluations against independent dose computation and TPS. To investigate the sensitivity of the new device, different types of systematic and random errors for leaf positions and linac output were introduced in IMRT treatment sequences. Results: The 2D gamma index evaluation of transmission detector based dose reconstruction showed an excellent agreement for all IMRT and VMAT plans compared to reference measurements (99.3±1.2)% and TPS (99.1±0.7)%. Good agreement was also obtained for 3D dose reconstruction based on TD read-out compared to dose computation (mean gamma value of PTV = 0.27±0.04). Only a minimal dose underestimation within the target volume was observed when analyzing DVH indices (<1%). Positional errors in leaf banks larger than 1mm and errors in linac output larger than 2% could clearly identified with the TD. Conclusion: Since 2D and 3D evaluations for all IMRT and VMAT treatment plans were in excellent agreement with reference measurements and dose computation, the new TD is suitable to qualify for routine treatment plan

Euratom Neutron Radiography Working Group

DEFF Research Database (Denmark)

Domanus, Joseph Czeslaw

1986-01-01

reactor fuel as well as establish standards for radiographic image quality of neutron radiographs. The NRWG meets once a year in each of the neutron radiography centers to review the progress made and draw plans for the future. Besides, ad-hoc sub-groups or. different topics within the field of neutron......In 1979 a Neutron Radiography Working Group (NRWG) was constituted within Buratom with the participation of all centers within the European Community at which neutron facilities were available. The main purpose of NRWG was to standardize methods and procedures used in neutron radiography of nuclear...... radiography are constituted. This paper reviews the activities and achievements of the NRWG and its sub-groups....

Swelling behavior detection of irradiated U-10Zr alloy fuel using indirect neutron radiography

Energy Technology Data Exchange (ETDEWEB)

Sun, Yong; Huo, He-yong; Wu, Yang [Institute of Nuclear Physics and Chemistry, Chinese Academy of Engineering Physics, Mianyang (China); Key Laboratory of Neutron Physics, Chinese Academy of Engineering Physics, Mianyang (China); Li, Jiangbo [Institute of Nuclear Physics and Chemistry, Chinese Academy of Engineering Physics, Mianyang (China); Zhou, Wei; Guo, Hai-bing [Institute of Nuclear Physics and Chemistry, Chinese Academy of Engineering Physics, Mianyang (China); Key Laboratory of Neutron Physics, Chinese Academy of Engineering Physics, Mianyang (China); Li, Hang, E-mail: lihang32@gmail.com [Institute of Nuclear Physics and Chemistry, Chinese Academy of Engineering Physics, Mianyang (China); Key Laboratory of Neutron Physics, Chinese Academy of Engineering Physics, Mianyang (China); Cao, Chao; Yin, Wei; Wang, Sheng; Liu, Bin; Feng, Qi-jie; Tang, Bin [Institute of Nuclear Physics and Chemistry, Chinese Academy of Engineering Physics, Mianyang (China); Key Laboratory of Neutron Physics, Chinese Academy of Engineering Physics, Mianyang (China)

2016-11-21

It is hopeful that fusion-fission hybrid energy system will become an effective approach to achieve long-term sustainable development of fission energy. U-10Zr alloy (which means the mass ratio of Zr is 10%) fuel is the key material of subcritical blanket for fusion-fission hybrid energy system which the irradiation performance need to be considered. Indirect neutron radiography is used to detect the irradiated U-10Zr alloy because of the high residual dose in this paper. Different burnup samples (0.1%, 0.3%, 0.5% and 0.7%) have been tested with a special indirect neutron radiography device at CMRR (China Mianyang Research Reactor). The resolution of the device is better than 50 µm and the quantitative analysis of swelling behaviors was carried out. The results show that the swelling behaviors relate well to burnup character which can be detected accurately by indirect neutron radiography.

Fracture healing: direct magnification versus conventional radiography

International Nuclear Information System (INIS)

Link, T.M.; Kessler, T.; Lange, T.; Overbeck, J.; Fiebich, M.; Peters, P.E.

1994-01-01

The aim of the study was to evaluate the potential of magnification radiography in diagnosing fracture healing and assessing its complications. Seventy-three patients with fractures or who had undergone osteotomy were radiographed with both conventional (non-magnified) and magnification (5-fold) techniques. Since 10 patients were radiographed twice and 1 three times, 83 radiographs using each technique were obtained. All radiographs were analysed and the findings correlated with the patients' follow-up studies. The microfocal X-ray unit used for magnification radiography had a focal spot size of 20-130 μm. As an imaging system, digital luminescence radiography was employed with magnification, while normal film-screen systems were used with conventional radiography. Magnification radiography proved superior to conventional radiography in 47% of cases: endosteal and periosteal callus formations were seen earlier and better in 26 cases, and osseous union could be evaluated with greater certainty in 33 cases. In 49% of cases magnification radiography was equal and in 4% inferior to conventional radiography. Additionally an ''inter-observer analysis'' was carried out. Anatomical and pathological structures were classified into one of four grades. Results were significantly (P < 0.01) better using magnification radiography. We conclude that the magnification technique is a good method for monitoring fracture healing in its early stages. (orig.)

Characterization of a gamma-ray source based on a laser-plasma accelerator with applications to radiography

International Nuclear Information System (INIS)

Edwards, R.D.; Sinclair, M.A.; Goldsack, T.J.; Krushelnick, K.; Beg, F.N.; Clark, E.L.; Dangor, A.E.; Najmudin, Z.; Tatarakis, M.; Walton, B.; Zepf, M.; Ledingham, K.W.D.; Spencer, I.; Norreys, P.A.; Clarke, R.J.; Kodama, R.; Toyama, Y.; Tampo, M.

2002-01-01

The application of high intensity laser-produced gamma rays is discussed with regard to picosecond resolution deep-penetration radiography. The spectrum and angular distribution of these gamma rays is measured using an array of thermoluminescent detectors for both an underdense (gas) target and an overdense (solid) target. It is found that the use of an underdense target in a laser plasma accelerator configuration produces a much more intense and directional source. The peak dose is also increased significantly. Radiography is demonstrated in these experiments and the source size is also estimated

Organ or tissue doses, effective dose and collective effective dose from X-ray diagnosis, in Japan