Transcript for CT Module 2
... the kV affects the penetrating power of the electrons that pass through the patient’s body. Use the slider bars on this animation to see how changing the mAs or the kVp will affect the output from the xray tube. ...
... the kV affects the penetrating power of the electrons that pass through the patient’s body. Use the slider bars on this animation to see how changing the mAs or the kVp will affect the output from the xray tube. ...
Attenuation
... the exposure. This is comparable to doubling the mAs, exposure time, or mA. – A 15% decrease in kilovoltage will halve the exposure. This is comparable to halving the mAs, exposure time, or mA. – Kilovoltage should not be the primary factor used to change density – 2nd Semester: Applied to maintain ...
... the exposure. This is comparable to doubling the mAs, exposure time, or mA. – A 15% decrease in kilovoltage will halve the exposure. This is comparable to halving the mAs, exposure time, or mA. – Kilovoltage should not be the primary factor used to change density – 2nd Semester: Applied to maintain ...
A Hybrid Approach for Accurate Estimation of the Scatter
... with the possibility of K- and L-shell fluorescent emission or Auger electron, coherent and incoherent scattering and pair production all together. In the first step, the user is supposed to provide an input file which includes information about the problem such as geometry specification, materials ...
... with the possibility of K- and L-shell fluorescent emission or Auger electron, coherent and incoherent scattering and pair production all together. In the first step, the user is supposed to provide an input file which includes information about the problem such as geometry specification, materials ...
Dosimerty/Radiation Therapy Terms
... HVL- thickness of absorbing material necessary to reduce the x-ray intensity to half its original value Bolus- tissue equivalent material that is usually placed on the patient to increase the skin dose and/or even out irregular contours in the patient Isodose curve- plotted percentage depth dose at ...
... HVL- thickness of absorbing material necessary to reduce the x-ray intensity to half its original value Bolus- tissue equivalent material that is usually placed on the patient to increase the skin dose and/or even out irregular contours in the patient Isodose curve- plotted percentage depth dose at ...
Imaging of Facet Joint Pathology - Washington Association of Nurse
... nuclear physicist, in 1963 described the mathematical basis for constructing a CT ...
... nuclear physicist, in 1963 described the mathematical basis for constructing a CT ...
Comparison of clinical and physical measures of image quality in
... assess and review the techniques used to obtain the images. The tube voltage is one of the variables that can be readily altered prior to exposure of each patient and view. The selection of appropriate tube voltage in analogue, screen-film radiology is a balance between the appropriate image quality ...
... assess and review the techniques used to obtain the images. The tube voltage is one of the variables that can be readily altered prior to exposure of each patient and view. The selection of appropriate tube voltage in analogue, screen-film radiology is a balance between the appropriate image quality ...
A Summary of Radiation Dose Guidelines and Limits Applicable to
... Because the last limitation above rules out pharmacologically active, toxic or system perturbing doses, the applicant need not be a physician licensed to prescribe drugs, although that would be the normal expectation. Applications meeting all of the above limitations will be subject to the same sort ...
... Because the last limitation above rules out pharmacologically active, toxic or system perturbing doses, the applicant need not be a physician licensed to prescribe drugs, although that would be the normal expectation. Applications meeting all of the above limitations will be subject to the same sort ...
BreAking the trend of increAsed rAdiAtion exposure to pAtients
... and monitoring system comprises a powerful tool for lowering radiation exposure and ensuring patient safety. Frush et al. [13] argue that to close performance gaps in radiation exposure, structures and systems must be put into place to provide a continous flow of information to key roles within the ...
... and monitoring system comprises a powerful tool for lowering radiation exposure and ensuring patient safety. Frush et al. [13] argue that to close performance gaps in radiation exposure, structures and systems must be put into place to provide a continous flow of information to key roles within the ...
X-ray detectors for digital radiography
... the ability of CT to display subtle differences in tissue attenuation. These outweighed the desire for high spatial resolution which could not be achieved with the coarse detectors and limited computer capacity available at the time, but which could be obtained with standard radiographic projection ...
... the ability of CT to display subtle differences in tissue attenuation. These outweighed the desire for high spatial resolution which could not be achieved with the coarse detectors and limited computer capacity available at the time, but which could be obtained with standard radiographic projection ...
Radiobiology Knowledge Level of Radiologists
... United States were linked to the CT examinations ISSN 1860-3122 ...
... United States were linked to the CT examinations ISSN 1860-3122 ...
Lecture 3 - IQ scatter and contrast agents 2013
... being imaged that will depend on the attenuation coefficients of the tissues (or contrast media), the thickness of structures, the nature of any overlapping tissues and the incident X-ray spectrum (kVp, filtration, etc – discussed previously) – Detector properties – film and digital detectors each h ...
... being imaged that will depend on the attenuation coefficients of the tissues (or contrast media), the thickness of structures, the nature of any overlapping tissues and the incident X-ray spectrum (kVp, filtration, etc – discussed previously) – Detector properties – film and digital detectors each h ...
Influence of CBCT exposure conditions on radiation dose
... be accurate and reliable, and currently provide sufficient resolution for the needs of dental imaging. Another difference is in the choice of parameters like kVp and mA, which can be operator controlled or preset into fixed combinations, depending on the machine. With such a new technology offered by ...
... be accurate and reliable, and currently provide sufficient resolution for the needs of dental imaging. Another difference is in the choice of parameters like kVp and mA, which can be operator controlled or preset into fixed combinations, depending on the machine. With such a new technology offered by ...
Dual Source/Dual energy- renal applications
... TCDS for removal of bone, since iodine is used as a contrast product in blood vessels. A beam of 80kv will be more attenuated by iodine than one beam of 140kv, due to the atomic number and properties of the atomic cloud. In contrast, this difference in calcium is no longer visible. This means that w ...
... TCDS for removal of bone, since iodine is used as a contrast product in blood vessels. A beam of 80kv will be more attenuated by iodine than one beam of 140kv, due to the atomic number and properties of the atomic cloud. In contrast, this difference in calcium is no longer visible. This means that w ...
Experimental feasibility of multi-energy photon-counting K
... electrical power starting at 10 µm for low power increasing to 100 µm at a maximum power of 65 W. The measurements presented below were taken at a 100 kVp beam voltage and a 100 µA beam current, which resulted in a beam spot of ∼12 µm (according to the manufacturer) and a measured x-ray flux of abou ...
... electrical power starting at 10 µm for low power increasing to 100 µm at a maximum power of 65 W. The measurements presented below were taken at a 100 kVp beam voltage and a 100 µA beam current, which resulted in a beam spot of ∼12 µm (according to the manufacturer) and a measured x-ray flux of abou ...
CT 成像原理介紹_1
... X-Ray Discovery X-ray was discovered by a German scientist Roentgen 100 years ago. This made people for the first time be able to ...
... X-Ray Discovery X-ray was discovered by a German scientist Roentgen 100 years ago. This made people for the first time be able to ...
Radiation - inayacollegedrmohammedemam
... Because Gamma rays can kill living cells, they are used to kill cancer cells without having to resort to difficult surgery. This is called "Radiotherapy", and works because cancer cells can't repair themselves when damaged by gamma rays, as healthy cells can ...
... Because Gamma rays can kill living cells, they are used to kill cancer cells without having to resort to difficult surgery. This is called "Radiotherapy", and works because cancer cells can't repair themselves when damaged by gamma rays, as healthy cells can ...
Quality Assurance and Quality Control of Equipment
... digital X-ray systems in medical imaging, QC is becoming increasingly more important. One of the reasons is that overexposed detectors, which provided a natural dose limitation for conventional image receptor systems are no longer observed in digital systems (Zoetelief et al., 2008). Also, such new ...
... digital X-ray systems in medical imaging, QC is becoming increasingly more important. One of the reasons is that overexposed detectors, which provided a natural dose limitation for conventional image receptor systems are no longer observed in digital systems (Zoetelief et al., 2008). Also, such new ...
Physics Radiology In-Training Test Questions for Diagnostic
... Chemical shift occurs as a result of the difference in the resonant frequency of protons associated with very hydrogenous (fat) tissues compared to protons associated with water molecules. Protons are localized by the variation of resonance frequencies under the influence of an external magnetic gra ...
... Chemical shift occurs as a result of the difference in the resonant frequency of protons associated with very hydrogenous (fat) tissues compared to protons associated with water molecules. Protons are localized by the variation of resonance frequencies under the influence of an external magnetic gra ...
accepted manuscript
... used non-destructive 3D imaging and analysis technique for the investigation of internal structures of a large variety of objects, including geomaterials. Although the possibilities of X-ray micro-CT are becoming better appreciated in earth science research, the demands on this technique are also ap ...
... used non-destructive 3D imaging and analysis technique for the investigation of internal structures of a large variety of objects, including geomaterials. Although the possibilities of X-ray micro-CT are becoming better appreciated in earth science research, the demands on this technique are also ap ...
technique - Montgomery College
... • Variable kVp, Fixed mAs– short contrast/more pt exposure • Fixed kVp, Variable mAs – Prefered, longer contrast less patient exposure • High kVp chart – For exams using 100 kVp or higher • Automatic exposure-PATIENT POSITIONING --VERY IMPORTANT ...
... • Variable kVp, Fixed mAs– short contrast/more pt exposure • Fixed kVp, Variable mAs – Prefered, longer contrast less patient exposure • High kVp chart – For exams using 100 kVp or higher • Automatic exposure-PATIENT POSITIONING --VERY IMPORTANT ...
Radiologic Technology
... Radiologic technologists, also referred to as radiographers, produce x-ray films (radiographs) of parts of the human body for use in diagnosing medical problems. They prepare patients for radiologic examinations by explaining the procedure, removing jewelry and other articles through which x-rays ca ...
... Radiologic technologists, also referred to as radiographers, produce x-ray films (radiographs) of parts of the human body for use in diagnosing medical problems. They prepare patients for radiologic examinations by explaining the procedure, removing jewelry and other articles through which x-rays ca ...
Trends in Dental Radiography Equipment and Patient Dose in the
... standard exposure factors for a range of radiographic images is also obtained from a questionnaire which is completed by the person carrying out the test. As the NRDs are set for an intra-oral mandibular molar radiograph and a standard adult panoramic radiograph, patient entrance doses for these rad ...
... standard exposure factors for a range of radiographic images is also obtained from a questionnaire which is completed by the person carrying out the test. As the NRDs are set for an intra-oral mandibular molar radiograph and a standard adult panoramic radiograph, patient entrance doses for these rad ...
3rd year/2nd semester
... Shape disorders on the X-ray image Concrescence is a condition of teeth where the cementum overlying the roots of at least two teeth join together. The cause can sometimes be attributed to trauma or crowding of teeth. The phenomenon of gemination arises when two teeth develop from one tooth bud and ...
... Shape disorders on the X-ray image Concrescence is a condition of teeth where the cementum overlying the roots of at least two teeth join together. The cause can sometimes be attributed to trauma or crowding of teeth. The phenomenon of gemination arises when two teeth develop from one tooth bud and ...
The use of 3D facial imaging and 3D cone beam CT
... The average person in the US receives an effective dose of about 3,000 micro Severts (Sv) per year (~8 micro Sv per day) from natural sources such as cosmic radiation from outer space and sources in the soil. The largest source of background radiation comes from radon gas in our homes which is about ...
... The average person in the US receives an effective dose of about 3,000 micro Severts (Sv) per year (~8 micro Sv per day) from natural sources such as cosmic radiation from outer space and sources in the soil. The largest source of background radiation comes from radon gas in our homes which is about ...
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.