European Commission. European guidelines on radiation protection
... permanently altered (a mutation). This may lead ultimately to the formation of a tumour. The latent period between exposure to X-rays and the clinical diagnosis of a tumour may be many years. The risk of a tumour being produced by a particular X-ray dose can be estimated; therefore, knowledge of the ...
... permanently altered (a mutation). This may lead ultimately to the formation of a tumour. The latent period between exposure to X-rays and the clinical diagnosis of a tumour may be many years. The risk of a tumour being produced by a particular X-ray dose can be estimated; therefore, knowledge of the ...
THE VETERINARY PUBLISHING COMPANY
... veil on the film, which reduces the contrast and the radiographic quality of the image. There are two ways to reduce scattered radiation on a radiographic image: the use of a device that restricts the beam and the use of an anti-scatter grid. Although there are several beam-restricting devices, the ...
... veil on the film, which reduces the contrast and the radiographic quality of the image. There are two ways to reduce scattered radiation on a radiographic image: the use of a device that restricts the beam and the use of an anti-scatter grid. Although there are several beam-restricting devices, the ...
The management of imaging dose during image-guided
... the margin information. If the treatment plan involves active motion management during treatment, then pretreatment fluoroscopic studies may be required to characterize the trajectory of the moving tumor. These trajectories form the basis for setting up a motion management scheme using either breath ...
... the margin information. If the treatment plan involves active motion management during treatment, then pretreatment fluoroscopic studies may be required to characterize the trajectory of the moving tumor. These trajectories form the basis for setting up a motion management scheme using either breath ...
The management of imaging dose during image-guided
... the margin information. If the treatment plan involves active motion management during treatment, then pretreatment fluoroscopic studies may be required to characterize the trajectory of the moving tumor. These trajectories form the basis for setting up a motion management scheme using either breath ...
... the margin information. If the treatment plan involves active motion management during treatment, then pretreatment fluoroscopic studies may be required to characterize the trajectory of the moving tumor. These trajectories form the basis for setting up a motion management scheme using either breath ...
Techniques and Applications of Automatic Tube Current Modulation
... tion reduction (up to 50%) with the online modulation technique was documented (1). In patients with circular cross-sectional geometry, beam attenuation is constant in all projections (x-ray beam projection angles). However, in a noncircular crosssectional geometry, attenuation varies strongly in di ...
... tion reduction (up to 50%) with the online modulation technique was documented (1). In patients with circular cross-sectional geometry, beam attenuation is constant in all projections (x-ray beam projection angles). However, in a noncircular crosssectional geometry, attenuation varies strongly in di ...
10. Organization of a Paediatric Radiology Department - RPOP
... standard equipment of lead-rubber shielding of the body in the immediate proximity of the diagnostic field • Special shielding has to be added for certain examinations to protect against external scattered and extra-focal radiation • Shielding devices must be correctly positioned: ...
... standard equipment of lead-rubber shielding of the body in the immediate proximity of the diagnostic field • Special shielding has to be added for certain examinations to protect against external scattered and extra-focal radiation • Shielding devices must be correctly positioned: ...
X-ray Tube and Generator
... Radiology for 1990 is approx. 20,000 manSv. On the basis of risk estimate this could be responsible for up to 700 cancer deaths/year ! Safety in Diagnostic ...
... Radiology for 1990 is approx. 20,000 manSv. On the basis of risk estimate this could be responsible for up to 700 cancer deaths/year ! Safety in Diagnostic ...
Highly reduced mass loss rates and increased litter layer in
... invertebrates had highly reduced abundance in the most contaminated areas either due to contamination from soil invertebrates or due to reductions in the abundance of food (Møller and Mousseau 2007). Evidence suggests that the abundance of saprophytic bacteria in contaminated soils is reduced (Zymen ...
... invertebrates had highly reduced abundance in the most contaminated areas either due to contamination from soil invertebrates or due to reductions in the abundance of food (Møller and Mousseau 2007). Evidence suggests that the abundance of saprophytic bacteria in contaminated soils is reduced (Zymen ...
A Monte Carlo based three-dimensional dose reconstruction
... pretreatment verification due to the high workload for developing, digitizing, and comparing the films with the planned dose. Full 3-D dose distribution verification will gain more insight into possible delivery problems. Several approaches are presented in the literature. Gels21 have the possibilit ...
... pretreatment verification due to the high workload for developing, digitizing, and comparing the films with the planned dose. Full 3-D dose distribution verification will gain more insight into possible delivery problems. Several approaches are presented in the literature. Gels21 have the possibilit ...
Tradeoffs in CT Image Quality and Radiation Dose
... This discussion focuses only on the reconstructed slice width in helical scanning and the factors that may influence it, which include: ...
... This discussion focuses only on the reconstructed slice width in helical scanning and the factors that may influence it, which include: ...
Guidelines for 18 F-FDG PET and PET-CT imaging in
... portion of the examination has become an issue of concern. In general, there is a trade off between CT image quality and radiation dose, and therefore, the amount of additional radiation depends primarily on the desired quality of CT images. As a consequence, it needs to be determined at each instit ...
... portion of the examination has become an issue of concern. In general, there is a trade off between CT image quality and radiation dose, and therefore, the amount of additional radiation depends primarily on the desired quality of CT images. As a consequence, it needs to be determined at each instit ...
CURRICULUMVITAE E. ISHMAEL PARSAI, Ph.D., FACRO, FAAPM
... Advanced Engineering Mathematics and Physics of Radiology, taught at UMC all during the graduate school years at UMC. ...
... Advanced Engineering Mathematics and Physics of Radiology, taught at UMC all during the graduate school years at UMC. ...
Cone Beam Computed Tomography
... in connection with images well suited for evaluation of calcified structures, like bone tissue and teeth (high contrast structures), has facilitated the rapid arrival of marketable CBCT scanners for operating in dental offices. Further, advantage for the CBCT scanners is the design to encounter some ...
... in connection with images well suited for evaluation of calcified structures, like bone tissue and teeth (high contrast structures), has facilitated the rapid arrival of marketable CBCT scanners for operating in dental offices. Further, advantage for the CBCT scanners is the design to encounter some ...
radiation protection in diagnostic radiology
... • In modern image intensifiers, this value should be much lower depending on patient size and projection ...
... • In modern image intensifiers, this value should be much lower depending on patient size and projection ...
guided radiation therapy
... al. (27) proposed the development of MV CT based on the 50-MV scanning photon beam of the racetrack microtron; this approach offers elevated contrast due to the increasing pair-production cross-section at X-ray energies over 1.022 MeV. More recently, Ruchala et al. have reported on the development o ...
... al. (27) proposed the development of MV CT based on the 50-MV scanning photon beam of the racetrack microtron; this approach offers elevated contrast due to the increasing pair-production cross-section at X-ray energies over 1.022 MeV. More recently, Ruchala et al. have reported on the development o ...
Imaging in radiotherapy - Nuclear Sciences and Applications
... In the developed countries, radiation therapy is employed in over 50% of cancer patients at some point in the management of their disease. As a local therapy, radiation therapy seeks to exploit technology to conform the treatment to the targeted structure while avoiding surrounding critical normal t ...
... In the developed countries, radiation therapy is employed in over 50% of cancer patients at some point in the management of their disease. As a local therapy, radiation therapy seeks to exploit technology to conform the treatment to the targeted structure while avoiding surrounding critical normal t ...
Imaging in Radiotherapy, IAEA Consultant`s meeting report
... In the developed countries, radiation therapy is employed in over 50% of cancer patients at some point in the management of their disease. As a local therapy, radiation therapy seeks to exploit technology to conform the treatment to the targeted structure while avoiding surrounding critical normal t ...
... In the developed countries, radiation therapy is employed in over 50% of cancer patients at some point in the management of their disease. As a local therapy, radiation therapy seeks to exploit technology to conform the treatment to the targeted structure while avoiding surrounding critical normal t ...
comparison of image quality test methods in computed
... difficult and time consuming to obtain by experimental measurements using physical phantoms. However, these can be calculated to a reasonable approximation, provided that sufficient data on the X-ray examination technique (including e.g. patient entrance dose value) are available. Today, such calcul ...
... difficult and time consuming to obtain by experimental measurements using physical phantoms. However, these can be calculated to a reasonable approximation, provided that sufficient data on the X-ray examination technique (including e.g. patient entrance dose value) are available. Today, such calcul ...
Package Insert - Zevacor Molecular
... The specific gamma ray constant (point source air kerma coefficient) for nitrogen N 13 is 5.9 R/hr/mCi (1.39 x 10 -6 Gy/hr/kBq) at 1 cm. The half-value layer (HVL) of lead (Pb) for 511 keV photons is 4 mm. Selected coefficients of attenuation are listed in Table 3 as a function of lead shield thickn ...
... The specific gamma ray constant (point source air kerma coefficient) for nitrogen N 13 is 5.9 R/hr/mCi (1.39 x 10 -6 Gy/hr/kBq) at 1 cm. The half-value layer (HVL) of lead (Pb) for 511 keV photons is 4 mm. Selected coefficients of attenuation are listed in Table 3 as a function of lead shield thickn ...
18. Optimization of protection in CT - RPOP
... practice in 1972 and revolutionized X Ray imaging by providing high quality images which reproduced transverse cross sections of the body. • Tissues are not superimposed on the image as they are in conventional projections • The CT provides improved low contrast resolution for better visualization o ...
... practice in 1972 and revolutionized X Ray imaging by providing high quality images which reproduced transverse cross sections of the body. • Tissues are not superimposed on the image as they are in conventional projections • The CT provides improved low contrast resolution for better visualization o ...
Managing Patient Dose in Multi-Detector Computed Tomography
... There are a number of new influencing parameters specific to MDCT which systematically increase or decrease patient dose compared to single-detector row CT scanners (SDCT). As in earlier developments in CT, there is potential for dose reduction, but the actual dose reduction depends upon how the sys ...
... There are a number of new influencing parameters specific to MDCT which systematically increase or decrease patient dose compared to single-detector row CT scanners (SDCT). As in earlier developments in CT, there is potential for dose reduction, but the actual dose reduction depends upon how the sys ...
Dose and image quality for a cone-beam C-arm
... in detector technology, image reconstruction, and image correction algorithms,4–8 three-dimensional 共3D兲 cone-beam C-arm imaging is now beginning to be used for low-contrast imaging applications such as detection of fresh intracranial bleeds.9 This new imaging modality must therefore be evaluated so ...
... in detector technology, image reconstruction, and image correction algorithms,4–8 three-dimensional 共3D兲 cone-beam C-arm imaging is now beginning to be used for low-contrast imaging applications such as detection of fresh intracranial bleeds.9 This new imaging modality must therefore be evaluated so ...
Evaluation of Suspected Pulmonary Embolism in Pregnancy
... (24%), and sweating (18%) were the four most common features at presentation (10); Powrie and coworkers (11) reported an abnormal alveolar–arterial gradient (> 15 mm Hg) in 8 of 17 (58%) pregnant women with confirmed PE. Cahill and colleagues (9) evaluated the predictive value of six presenting clin ...
... (24%), and sweating (18%) were the four most common features at presentation (10); Powrie and coworkers (11) reported an abnormal alveolar–arterial gradient (> 15 mm Hg) in 8 of 17 (58%) pregnant women with confirmed PE. Cahill and colleagues (9) evaluated the predictive value of six presenting clin ...
Self-Referral CT Screening Application Guide (PDF: 420KB/34pages)
... community. Our vision is to reduce unnecessary radiation exposure from the use of ionizing radiation producing equipment. Introduction The Minnesota Department of Health (MDH) regulates the testing of individuals with x-ray equipment to detect or evaluate health conditions when the tests are not spe ...
... community. Our vision is to reduce unnecessary radiation exposure from the use of ionizing radiation producing equipment. Introduction The Minnesota Department of Health (MDH) regulates the testing of individuals with x-ray equipment to detect or evaluate health conditions when the tests are not spe ...
Slate_gray covers.indd - American Society for Radiation Oncology
... achieve but we do not believe that they are impossible. We recognize that, in a declining economy, these high bars may prove a challenge but we believe this interdisciplinary document will help facility leaders advocate on behalf of patients from a position of strength. The authors wish this book to ...
... achieve but we do not believe that they are impossible. We recognize that, in a declining economy, these high bars may prove a challenge but we believe this interdisciplinary document will help facility leaders advocate on behalf of patients from a position of strength. The authors wish this book to ...
Radiation burn
A radiation burn is damage to the skin or other biological tissue caused by exposure to radiation. The radiation types of greatest concern are thermal radiation, radio frequency energy, ultraviolet light and ionizing radiation.The most common type of radiation burn is a sunburn caused by UV radiation. High exposure to X-rays during diagnostic medical imaging or radiotherapy can also result in radiation burns. As the ionizing radiation interacts with cells within the body—damaging them—the body responds to this damage, typically resulting in erythema—that is, redness around the damaged area. Radiation burns are often associated with radiation-induced cancer due to the ability of ionizing radiation to interact with and damage DNA, occasionally inducing a cell to become cancerous. Cavity magnetrons can be improperly used to create surface and internal burning. Depending on the photon energy, gamma radiation can cause very deep gamma burns, with 60Co internal burns are common. Beta burns tend to be shallow as beta particles are not able to penetrate deep into the person; these burns can be similar to sunburn.Radiation burns can also occur with high power radio transmitters at any frequency where the body absorbs radio frequency energy and converts it to heat. The U.S. Federal Communications Commission (FCC) considers 50 watts to be the lowest power above which radio stations must evaluate emission safety. Frequencies considered especially dangerous occur where the human body can become resonant, at 35 MHz, 70 MHz, 80-100 MHz, 400 MHz, and 1 GHz. Exposure to microwaves of too high intensity can cause microwave burns.