上海交通大学医学院 教 案 课程名称 Medical Imaging 2008年3月1日
... X-rays are a form of radiant energy that is similar in many ways to visible light. X-rays differ from visible light in that they have a very short wavelength and are able to penetrate many substances that are opaque to light. The x-ray beam is produced by bombarding a tungsten target with an electr ...
... X-rays are a form of radiant energy that is similar in many ways to visible light. X-rays differ from visible light in that they have a very short wavelength and are able to penetrate many substances that are opaque to light. The x-ray beam is produced by bombarding a tungsten target with an electr ...
EL CAMINO COLLEGE RADIOLOGIC TECHNOLOGY PROGRAM
... treatment of disease by means of high energy x-rays (GAMMA) or radioactive substances ...
... treatment of disease by means of high energy x-rays (GAMMA) or radioactive substances ...
ACR Practice Guideline for Diagnostic Reference Levels in Medical
... an investigation level to identify unusually high radiation doses or exposure levels for common diagnostic medical X-ray imaging procedures [1-3]. Reference levels are based on actual patient doses for specific procedures measured at a number of representative clinical facilities. The levels are set ...
... an investigation level to identify unusually high radiation doses or exposure levels for common diagnostic medical X-ray imaging procedures [1-3]. Reference levels are based on actual patient doses for specific procedures measured at a number of representative clinical facilities. The levels are set ...
simCT_RT - University of Washington
... • X-ray tubes produce a range of energies. • Lower energy photons are more easily scattered/absorbed. • The x-ray beam gets ‘harder’ (a higher percentage high energy photons) as it passes through the object. ...
... • X-ray tubes produce a range of energies. • Lower energy photons are more easily scattered/absorbed. • The x-ray beam gets ‘harder’ (a higher percentage high energy photons) as it passes through the object. ...
The deposition of films by plasma techniques and the plasma
... ray diffractometry (GIXD) and x-ray reflectometry (XR) have been introduced as well suited tools for investigations of plasma deposited thin layers. These x-ray methods have a number of advantages compared to other commonly used techniques They are nondestructive techniques, therefore a sample can b ...
... ray diffractometry (GIXD) and x-ray reflectometry (XR) have been introduced as well suited tools for investigations of plasma deposited thin layers. These x-ray methods have a number of advantages compared to other commonly used techniques They are nondestructive techniques, therefore a sample can b ...
Abstract
... ray diffractometry (GIXD) and x-ray reflectometry (XR) have been introduced as well suited tools for investigations of plasma deposited thin layers. These x-ray methods have a number of advantages compared to other commonly used techniques They are nondestructive techniques, therefore a sample can b ...
... ray diffractometry (GIXD) and x-ray reflectometry (XR) have been introduced as well suited tools for investigations of plasma deposited thin layers. These x-ray methods have a number of advantages compared to other commonly used techniques They are nondestructive techniques, therefore a sample can b ...
General Principles of Tomography
... Assignment of display brightness to pixel values does not disturb original pixel values in memory ...
... Assignment of display brightness to pixel values does not disturb original pixel values in memory ...
- Iranian Journal of Medical Physics
... in this study, are summarized in Table 1. The significant variations in ESD values, observed in this study, indicate that reducing patient dose can be achieved by changing technical parameters (e.g., kVp and mAs), without wering the image quality; also, these variations are influenced by patient's b ...
... in this study, are summarized in Table 1. The significant variations in ESD values, observed in this study, indicate that reducing patient dose can be achieved by changing technical parameters (e.g., kVp and mAs), without wering the image quality; also, these variations are influenced by patient's b ...
What Parents Should Know about the Safety of
... use of x-rays to create dental images is not painful, but during the procedure, the child must stay still or else the image may be fuzzy. In some circumstances, parents may be asked to help keep their children still while dental images are taken. Depending on the area of the jaw imaged and the type ...
... use of x-rays to create dental images is not painful, but during the procedure, the child must stay still or else the image may be fuzzy. In some circumstances, parents may be asked to help keep their children still while dental images are taken. Depending on the area of the jaw imaged and the type ...
The art of medical imaging
... The cathode rays converged into one point on the glass wall, which resulted in a much sharper image. However, the localized heat load on the glass built up tremendously, which shattered a number of tubes. The next logical step, taken shortly thereafter, was to place a platinum anticathode in the tub ...
... The cathode rays converged into one point on the glass wall, which resulted in a much sharper image. However, the localized heat load on the glass built up tremendously, which shattered a number of tubes. The next logical step, taken shortly thereafter, was to place a platinum anticathode in the tub ...
Introduction to medical imaging
... superior spatial resolution of the technique and in part to the fact that MR images are insensitive to bone — in CT, the proximity of bony vertebrae to the spinal cord make this region difficult to image as a result of partial volume effects. • Furthermore, patients with pacemakers, artificial joint ...
... superior spatial resolution of the technique and in part to the fact that MR images are insensitive to bone — in CT, the proximity of bony vertebrae to the spinal cord make this region difficult to image as a result of partial volume effects. • Furthermore, patients with pacemakers, artificial joint ...
textbook and other materials
... Students must achieve a 75% average on test scores alone before other scores are included in the final average. A test score average of less than 75% results in failure of the course. Students must achieve a “C” average in this course in order to continue in the Radiography program. Any student that ...
... Students must achieve a 75% average on test scores alone before other scores are included in the final average. A test score average of less than 75% results in failure of the course. Students must achieve a “C” average in this course in order to continue in the Radiography program. Any student that ...
Reports and Activities of International Commission on Radiation
... Radiation units and Measurements ICRU Hans-Georg Menzel Chairman – ICRU Main Commission CERN (retired) ...
... Radiation units and Measurements ICRU Hans-Georg Menzel Chairman – ICRU Main Commission CERN (retired) ...
Computed Tomography (CT) - Sinuses
... patient needs to lie still is reduced. Though the scanning itself causes no pain, there may be some discomfort from having to remain still for several minutes. If you have a hard time staying still, are claustrophobic or have chronic pain, you may find a CT exam to be stressful. The technologist or ...
... patient needs to lie still is reduced. Though the scanning itself causes no pain, there may be some discomfort from having to remain still for several minutes. If you have a hard time staying still, are claustrophobic or have chronic pain, you may find a CT exam to be stressful. The technologist or ...
Medical Imaging - Engr. Ijlal Haider
... of the body in a way which is as non-invasive as possible. An imaging study can be used to identify unusual things inside the body, such as broken bones, tumors, leaking blood vessels, and so forth. One of the most famous types of diagnostic imaging is the x-ray, which uses radiation to take a stati ...
... of the body in a way which is as non-invasive as possible. An imaging study can be used to identify unusual things inside the body, such as broken bones, tumors, leaking blood vessels, and so forth. One of the most famous types of diagnostic imaging is the x-ray, which uses radiation to take a stati ...
Hot Topic: Limiting Radiation Exposure in Radiographic Evaluation
... Dual- and Multi-Energy CT: Principles, Technical Approaches, and ...
... Dual- and Multi-Energy CT: Principles, Technical Approaches, and ...
Mapping cellular magnesium using X-ray
... measurement. The concentration map is different from the fluorescence intensity map shown in Figure 1e: in the nuclear region, the concentration is quite uniform, indicating that the strong intensity peaks found in the fluorescence map were only related to larger thickness (see Fig. 2a-b). Interesti ...
... measurement. The concentration map is different from the fluorescence intensity map shown in Figure 1e: in the nuclear region, the concentration is quite uniform, indicating that the strong intensity peaks found in the fluorescence map were only related to larger thickness (see Fig. 2a-b). Interesti ...
Chapter 23 Technological methods of medical diagnosis
... 17. Use a table to summarise situations in which CT scans are a superior diagnostic tool to Xrays and ultrasound. 18. An endoscope is used to take a biopsy of a small tumour in the oesophagus, which leads from the mouth to the stomach. Explain how an endoscope can be used to do this. 19. List some a ...
... 17. Use a table to summarise situations in which CT scans are a superior diagnostic tool to Xrays and ultrasound. 18. An endoscope is used to take a biopsy of a small tumour in the oesophagus, which leads from the mouth to the stomach. Explain how an endoscope can be used to do this. 19. List some a ...
Inflammatory Lesions of the jaws
... Recognize when 3D imaging will assist the doctor in achieving superior outcomes ...
... Recognize when 3D imaging will assist the doctor in achieving superior outcomes ...
CT Colonography - RadiologyInfo.org
... How does the procedure work? In many ways CT scanning works very much like other x-ray examinations. X-rays are a form of radiation—like light or radio waves—that can be directed at the body. Different body parts absorb the x-rays in varying degrees. In a conventional x-ray exam, a small burst of ra ...
... How does the procedure work? In many ways CT scanning works very much like other x-ray examinations. X-rays are a form of radiation—like light or radio waves—that can be directed at the body. Different body parts absorb the x-rays in varying degrees. In a conventional x-ray exam, a small burst of ra ...
Medical Imaging Tests during Pregnancy
... can tell you how much radiation your baby could receive from any imaging tests you may be given. Medical imaging tests that use radiation do not increase the overall number of babies born with birth defects. Even if you and your baby do not have any imaging tests with radiation, there is still a cha ...
... can tell you how much radiation your baby could receive from any imaging tests you may be given. Medical imaging tests that use radiation do not increase the overall number of babies born with birth defects. Even if you and your baby do not have any imaging tests with radiation, there is still a cha ...
example from X-ray Diagnostic Radiology
... - Service engineers - not interested (have their own tests); - Medical Physicists - essential for the job, but boring…; - Scientists - not suitable for research; - Students - enjoyed as the practical part of their learning - Professional Organisations - very important ...
... - Service engineers - not interested (have their own tests); - Medical Physicists - essential for the job, but boring…; - Scientists - not suitable for research; - Students - enjoyed as the practical part of their learning - Professional Organisations - very important ...
Discuss briefly breast implant displaced procedure. * Extreme
... Steep range radiography is modification of standard exposure techniques to record on the film a wide range of tissue densities using one radiographic exposure. In multiple radiography a special type of cassette is used to place in the cassette two pairs of intensifying screens which can be exposed s ...
... Steep range radiography is modification of standard exposure techniques to record on the film a wide range of tissue densities using one radiographic exposure. In multiple radiography a special type of cassette is used to place in the cassette two pairs of intensifying screens which can be exposed s ...
X-ray tube in CT scanner
... EBT Design specifics: As in standard X-Ray tubes, part of the electron current energy when hitting the tungsten target is converted into photons. However, instead of spinning a small target anode in order to dissipate waste heat, the electron current focus spot is swept along a large stationary targ ...
... EBT Design specifics: As in standard X-Ray tubes, part of the electron current energy when hitting the tungsten target is converted into photons. However, instead of spinning a small target anode in order to dissipate waste heat, the electron current focus spot is swept along a large stationary targ ...
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.