Applied Physics Radiation Oncology
... films, known as portal images, are made with electronic methods, or with film and/or cassettes designed for high-energy exposure. Film-holding cassettes often include a metal screen that produces electrons through high-energy photon interaction. These compton electrons help produce the radiographic ...
... films, known as portal images, are made with electronic methods, or with film and/or cassettes designed for high-energy exposure. Film-holding cassettes often include a metal screen that produces electrons through high-energy photon interaction. These compton electrons help produce the radiographic ...
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 ...
pdf version
... (1) The approved program for a certificate of limited x-ray machine operation shall include didactic and clinical instruction of the type and quantity indicated in the applicable subsections of this section. The recommended topics for radiation safety and protection should include a discussion of io ...
... (1) The approved program for a certificate of limited x-ray machine operation shall include didactic and clinical instruction of the type and quantity indicated in the applicable subsections of this section. The recommended topics for radiation safety and protection should include a discussion of io ...
Storage Phosphors for Medical Imaging
... 3. The image information stored in the phosphor should have slow fading in dark at room temperature, i.e., electron- and hole traps should be stable. In practice, the so-called dark-decay of the stored image in a CR plate is between 10 and 25% in the first hour after X-ray exposure. 4. The stimulati ...
... 3. The image information stored in the phosphor should have slow fading in dark at room temperature, i.e., electron- and hole traps should be stable. In practice, the so-called dark-decay of the stored image in a CR plate is between 10 and 25% in the first hour after X-ray exposure. 4. The stimulati ...
AAPM/RSNA Physics Tutorial for Residents: Topics in CT
... dose is much larger than the exit skin dose, creating a large radiation dose gradient across the patient (Fig 1). In contrast, the tomographic exposure of CT scans with a full 360° rotation results in a radially symmetric radiation dose gradient within the patient. That is, in a uniform circular obj ...
... dose is much larger than the exit skin dose, creating a large radiation dose gradient across the patient (Fig 1). In contrast, the tomographic exposure of CT scans with a full 360° rotation results in a radially symmetric radiation dose gradient within the patient. That is, in a uniform circular obj ...
Understanding Radiation Units
... • Cumulative dose to IRP can be a good indicator of doses higher than the thresholds for skin injures • A “trigger value” for cumulative dose can be adopted to alert interventionalists the threshold for skin erythema could be reached. • A follow-up protocol can be adopted. ...
... • Cumulative dose to IRP can be a good indicator of doses higher than the thresholds for skin injures • A “trigger value” for cumulative dose can be adopted to alert interventionalists the threshold for skin erythema could be reached. • A follow-up protocol can be adopted. ...
19. Optimization of protection in mammography - RPOP
... Dosimetry quantities ESAK can be determined by: • a TLD or OSL dosimeter calibrated in terms of air kerma free-in-air at an HVL as close as possible to 0.4 mm Al with a standard phantom • a TLD or OSL dosimeter calibrated in terms of air kerma free-in-air at a HVL as close as possible to 0.4 mm Al ...
... Dosimetry quantities ESAK can be determined by: • a TLD or OSL dosimeter calibrated in terms of air kerma free-in-air at an HVL as close as possible to 0.4 mm Al with a standard phantom • a TLD or OSL dosimeter calibrated in terms of air kerma free-in-air at a HVL as close as possible to 0.4 mm Al ...
RADIATION PROTECTION IN DIAGNOSTIC RADIOLOGY
... Dosimetry quantities ESAK can be determined by: • a TLD or OSL dosimeter calibrated in terms of air kerma free-in-air at an HVL as close as possible to 0.4 mm Al with a standard phantom • a TLD or OSL dosimeter calibrated in terms of air kerma free-in-air at a HVL as close as possible to 0.4 mm Al ...
... Dosimetry quantities ESAK can be determined by: • a TLD or OSL dosimeter calibrated in terms of air kerma free-in-air at an HVL as close as possible to 0.4 mm Al with a standard phantom • a TLD or OSL dosimeter calibrated in terms of air kerma free-in-air at a HVL as close as possible to 0.4 mm Al ...
Storage Phosphors for Medical Imaging
... 3. The image information stored in the phosphor should have slow fading in dark at room temperature, i.e., electron- and hole traps should be stable. In practice, the so-called dark-decay of the stored image in a CR plate is between 10 and 25% in the first hour after X-ray exposure. 4. The stimulati ...
... 3. The image information stored in the phosphor should have slow fading in dark at room temperature, i.e., electron- and hole traps should be stable. In practice, the so-called dark-decay of the stored image in a CR plate is between 10 and 25% in the first hour after X-ray exposure. 4. The stimulati ...
Geometric Accuracy of 3-D X-Ray Image
... Abstract. Image guided interventions often involve C-arm X-ray imaging systems. State-of-the art fluoroscopy systems not only offer 2-D Xray imaging, but they can also be used to obtain 3-D cone-beam tomographic data sets. These 3-D volumetric images can be used for image guidance and device navigatio ...
... Abstract. Image guided interventions often involve C-arm X-ray imaging systems. State-of-the art fluoroscopy systems not only offer 2-D Xray imaging, but they can also be used to obtain 3-D cone-beam tomographic data sets. These 3-D volumetric images can be used for image guidance and device navigatio ...
Radiation Information for Hospital Personnel
... required to detect the presence of the invisible types of EM radiation. Figure 1 shows the electromagnetic spectrum, a comparison of energies and properties associated with different types of EM radiation. The term radiation also is used to describe very fast moving particles, such as electrons and ...
... required to detect the presence of the invisible types of EM radiation. Figure 1 shows the electromagnetic spectrum, a comparison of energies and properties associated with different types of EM radiation. The term radiation also is used to describe very fast moving particles, such as electrons and ...
Quantitative assessment of scatter correction techniques
... The work presented in this thesis could not have been done without the support and hard work of multi-disciplinary teams. I would like to first thank Dr. Eric A. Hoffman, my thesis advisor, whose mentorship guided me throughout my time in the lab and with this project. I would like to thank Dr. Will ...
... The work presented in this thesis could not have been done without the support and hard work of multi-disciplinary teams. I would like to first thank Dr. Eric A. Hoffman, my thesis advisor, whose mentorship guided me throughout my time in the lab and with this project. I would like to thank Dr. Will ...
Dosimetry of 3 CBCT devices for oral and maxillofacial radiology
... the soft tissue contours of the chin and nose were captured at the margins of the field. Phantom levels 2 – 8 were included in the full FOV examinations produced by each unit. Midsagittal reconstructions resulting from these examinations can be seen in Figure 2. X-ray parameters of kV and mA are aut ...
... the soft tissue contours of the chin and nose were captured at the margins of the field. Phantom levels 2 – 8 were included in the full FOV examinations produced by each unit. Midsagittal reconstructions resulting from these examinations can be seen in Figure 2. X-ray parameters of kV and mA are aut ...
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... Beam shaping filters specific to cardiac CT ...
... Beam shaping filters specific to cardiac CT ...
Cone Beam Computed Tomography in Endodontics: An Overview.
... delayed healing, evaluating potential obstacles to the retreatment, as well as aid surgical considerations. Limitations of Conventional 2D Imaging Intraoral radiography is based on the transmission, attenuation, and recording of X-rays on an analog film, and requires optimized geometric configuratio ...
... delayed healing, evaluating potential obstacles to the retreatment, as well as aid surgical considerations. Limitations of Conventional 2D Imaging Intraoral radiography is based on the transmission, attenuation, and recording of X-rays on an analog film, and requires optimized geometric configuratio ...
14th International Conference for X
... We would like to dedicate this conference to Dr. Jim Dunn. Jim, an outstanding scientist and a dear friend, is recognized for major contributions to the field of X-ray lasers in which he was active for most of his career. He also made significant contributions to the study of high energy density pla ...
... We would like to dedicate this conference to Dr. Jim Dunn. Jim, an outstanding scientist and a dear friend, is recognized for major contributions to the field of X-ray lasers in which he was active for most of his career. He also made significant contributions to the study of high energy density pla ...
Weightbearing CBCT, MDCT, and 2D imaging dosimetry of the foot
... Optically stimulated luminescent dosimeters (OSL) (Nanodot, Landauer, Inc., Glenwood, IL) were used for dosimetry for this project. NanoDots are plastic disks infused with aluminum oxide doped with carbon (Al2O3: C). The trace amounts of Carbon in the Al2O3 crystal lattice create imperfections that ...
... Optically stimulated luminescent dosimeters (OSL) (Nanodot, Landauer, Inc., Glenwood, IL) were used for dosimetry for this project. NanoDots are plastic disks infused with aluminum oxide doped with carbon (Al2O3: C). The trace amounts of Carbon in the Al2O3 crystal lattice create imperfections that ...
Safety Code 35: Radiation Protection in Radiology
... The need for radiation protection exists because exposure to ionizing radiation can result in deleterious effects that manifest themselves not only in the exposed individuals but in their descendants as well. These effects are called somatic and genetic effects, respectively. Somatic effects are cha ...
... The need for radiation protection exists because exposure to ionizing radiation can result in deleterious effects that manifest themselves not only in the exposed individuals but in their descendants as well. These effects are called somatic and genetic effects, respectively. Somatic effects are cha ...
Safety Code 35: Radiation Protection in Radiology
... The need for radiation protection exists because exposure to ionizing radiation can result in deleterious effects that manifest themselves not only in the exposed individuals but in their descendants as well. These effects are called somatic and genetic effects, respectively. Somatic effects are cha ...
... The need for radiation protection exists because exposure to ionizing radiation can result in deleterious effects that manifest themselves not only in the exposed individuals but in their descendants as well. These effects are called somatic and genetic effects, respectively. Somatic effects are cha ...
reduced radiation exposure and iodine load at low tube kilovoltage
... or pelvis, the mean estimated effective dose can still reach 15 mSv on average (range, 13–40 mSv) as reported by Mettler et al. [16] . Other authors have published lower observed effective radiation doses ranging between 3 and 5 mSv [14,17] . As the benefit:risk ratio for using CT is high and the h ...
... or pelvis, the mean estimated effective dose can still reach 15 mSv on average (range, 13–40 mSv) as reported by Mettler et al. [16] . Other authors have published lower observed effective radiation doses ranging between 3 and 5 mSv [14,17] . As the benefit:risk ratio for using CT is high and the h ...
Closing the Gap to the Diffraction Limit: Near
... with 50 nm resolution using tabletop coherent soft x-ray sources. This work represents the first high resolution demonstrations of coherent diffractive or lensless imaging using tabletop extreme ultraviolet and soft x-ray sources [4, 5]. This dissertation also presents the first use of field curvature c ...
... with 50 nm resolution using tabletop coherent soft x-ray sources. This work represents the first high resolution demonstrations of coherent diffractive or lensless imaging using tabletop extreme ultraviolet and soft x-ray sources [4, 5]. This dissertation also presents the first use of field curvature c ...
Cancer risks associated with external radiation from diagnostic
... doses, and even higher levels for long-term exposure,31 but recent human and mechanistic studies suggest a lower (eg, around 0.5 Gy) or no threshold.37 Stochastic effects, including cancer and hereditary effects, are caused by a mutation or other permanent change in which the cell remains viable. Th ...
... doses, and even higher levels for long-term exposure,31 but recent human and mechanistic studies suggest a lower (eg, around 0.5 Gy) or no threshold.37 Stochastic effects, including cancer and hereditary effects, are caused by a mutation or other permanent change in which the cell remains viable. Th ...
Foreword: Radiology Select Volume 5—Radiation Dose and
... number of articles published on the topic of radiation dose reduction every year indicate that we are far from a stable situation from which the medical community could develop universal consensus on best practices for radiation dose management. The aim of this edition of Radiology Select was, there ...
... number of articles published on the topic of radiation dose reduction every year indicate that we are far from a stable situation from which the medical community could develop universal consensus on best practices for radiation dose management. The aim of this edition of Radiology Select was, there ...
Imaging doses from the Elekta Synergy X
... radiotherapy linear accelerators specifically designed for image guided radiotherapy (IGRT). It has a kilo-voltage X-ray source and opposing amorphous silicon flat panel imager, both mounted at 90˚ to the treatment head for the acquisition of kV X-ray projection images for radiography and fluoroscop ...
... radiotherapy linear accelerators specifically designed for image guided radiotherapy (IGRT). It has a kilo-voltage X-ray source and opposing amorphous silicon flat panel imager, both mounted at 90˚ to the treatment head for the acquisition of kV X-ray projection images for radiography and fluoroscop ...
Radiological Protection in Paediatric Diagnostic and Interventional
... increased by 70 percent. It was also estimated that worldwide there were about 3.6 billion ...
... increased by 70 percent. It was also estimated that worldwide there were about 3.6 billion ...
X-ray
X-radiation (composed of X-rays) is a form of electromagnetic radiation. Most X-rays have a wavelength ranging from 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz (3×1016 Hz to 3×1019 Hz) and energies in the range 100 eV to 100 keV. X-ray wavelengths are shorter than those of UV rays and typically longer than those of gamma rays. In many languages, X-radiation is referred to with terms meaning Röntgen radiation, after Wilhelm Röntgen, who is usually credited as its discoverer, and who had named it X-radiation to signify an unknown type of radiation. Spelling of X-ray(s) in the English language includes the variants x-ray(s), xray(s) and X ray(s).X-rays with photon energies above 5–10 keV (below 0.2–0.1 nm wavelength) are called hard X-rays, while those with lower energy are called soft X-rays. Due to their penetrating ability, hard X-rays are widely used to image the inside of objects, e.g., in medical radiography and airport security. As a result, the term X-ray is metonymically used to refer to a radiographic image produced using this method, in addition to the method itself. Since the wavelengths of hard X-rays are similar to the size of atoms they are also useful for determining crystal structures by X-ray crystallography. By contrast, soft X-rays are easily absorbed in air and the attenuation length of 600 eV (~2 nm) X-rays in water is less than 1 micrometer.There is no universal consensus for a definition distinguishing between X-rays and gamma rays. One common practice is to distinguish between the two types of radiation based on their source: X-rays are emitted by electrons, while gamma rays are emitted by the atomic nucleus. This definition has several problems; other processes also can generate these high energy photons, or sometimes the method of generation is not known. One common alternative is to distinguish X- and gamma radiation on the basis of wavelength (or equivalently, frequency or photon energy), with radiation shorter than some arbitrary wavelength, such as 10−11 m (0.1 Å), defined as gamma radiation.This criterion assigns a photon to an unambiguous category, but is only possible if wavelength is known. (Some measurement techniques do not distinguish between detected wavelengths.) However, these two definitions often coincide since the electromagnetic radiation emitted by X-ray tubes generally has a longer wavelength and lower photon energy than the radiation emitted by radioactive nuclei.Occasionally, one term or the other is used in specific contexts due to historical precedent, based on measurement (detection) technique, or based on their intended use rather than their wavelength or source.Thus, gamma-rays generated for medical and industrial uses, for example radiotherapy, in the ranges of 6–20 MeV, can in this context also be referred to as X-rays.