The Influence of X-Ray Spectra Filtration on Image Quality
... reduced scan times, faster rotation speed and thinner slices leading to higher image quality. Moreover, recent developments in x-ray tube design allow to lower patient dose. The effective dose exposure of a typical CT examination is now between 1 and 20 mSv depending on the scan length and scan regi ...
... reduced scan times, faster rotation speed and thinner slices leading to higher image quality. Moreover, recent developments in x-ray tube design allow to lower patient dose. The effective dose exposure of a typical CT examination is now between 1 and 20 mSv depending on the scan length and scan regi ...
Chapter_050
... Process of recording of x-ray images or radiographs. X-rays are produced in a vacuum tube, creating a radiation field that can penetrate most substances and form an image on film. Radiopaque—substance that is not easily penetrated by radiation and so appears light on the radiograph (bone). Radioluce ...
... Process of recording of x-ray images or radiographs. X-rays are produced in a vacuum tube, creating a radiation field that can penetrate most substances and form an image on film. Radiopaque—substance that is not easily penetrated by radiation and so appears light on the radiograph (bone). Radioluce ...
Chapter_050
... Process of recording of x-ray images or radiographs. X-rays are produced in a vacuum tube, creating a radiation field that can penetrate most substances and form an image on film. Radiopaque—substance that is not easily penetrated by radiation and so appears light on the radiograph (bone). Radioluce ...
... Process of recording of x-ray images or radiographs. X-rays are produced in a vacuum tube, creating a radiation field that can penetrate most substances and form an image on film. Radiopaque—substance that is not easily penetrated by radiation and so appears light on the radiograph (bone). Radioluce ...
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 ...
Digital Medical Linear Accelerator Specifications. Fighting cancer
... chance of affecting healthy surrounding tissue. And precision alone at the cost of speed means to lose short treatment times, high patient throughput, and a convenient patient experience out of sight. That’s why our radiation therapy solutions aim to incorporate the optimum of both, an intelligent b ...
... chance of affecting healthy surrounding tissue. And precision alone at the cost of speed means to lose short treatment times, high patient throughput, and a convenient patient experience out of sight. That’s why our radiation therapy solutions aim to incorporate the optimum of both, an intelligent b ...
Contrast Optimization in Low Radiation Dose Imaging
... ever, it is important to note that small reductions in kV have a more substantial effect on radiation dose reduction.5,6 Moreover, for iodinated contrast-enhanced exams, lower kVp values result not only in lower radiation dose exposure, but also higher contrast enhancement, especially when employed ...
... ever, it is important to note that small reductions in kV have a more substantial effect on radiation dose reduction.5,6 Moreover, for iodinated contrast-enhanced exams, lower kVp values result not only in lower radiation dose exposure, but also higher contrast enhancement, especially when employed ...
Maximizing dose reductions with cardiac CT | SpringerLink
... which will both minimize radiation and afford better image quality, is to restrict the xy field of view. A smaller xy field of view will improve image quality, as the FOV divided by 512 is the resolution in the X–Y axis (to an optimal resolution of about 0.3–0.35 mm for current scanners). The bowtie ...
... which will both minimize radiation and afford better image quality, is to restrict the xy field of view. A smaller xy field of view will improve image quality, as the FOV divided by 512 is the resolution in the X–Y axis (to an optimal resolution of about 0.3–0.35 mm for current scanners). The bowtie ...
Radiation Safety in the Cath Lab
... Vary tube angle if possible to change skin exposed Position table & image receptor: x-ray tube close to pt increases dose; high image receptor incr. scatter Keep pt & operator body parts out of field of view Maximize shielding and distance from x-ray source for all personnel Manage and monitor dose ...
... Vary tube angle if possible to change skin exposed Position table & image receptor: x-ray tube close to pt increases dose; high image receptor incr. scatter Keep pt & operator body parts out of field of view Maximize shielding and distance from x-ray source for all personnel Manage and monitor dose ...
Enhancing Patient Safety in Today`s Healthcare
... With the availability of faster scanners, there are reduced motion artifacts. This is a key advantage for pediatric CVCT and is leading to increased use of CTA for the evaluation of congenital heart disease in pediatric patients. In this patient population, it is particularly important to modify pro ...
... With the availability of faster scanners, there are reduced motion artifacts. This is a key advantage for pediatric CVCT and is leading to increased use of CTA for the evaluation of congenital heart disease in pediatric patients. In this patient population, it is particularly important to modify pro ...
Care of the X
... creates pitting, the formation of small crevices into which electrons from the filament may enter. ...
... creates pitting, the formation of small crevices into which electrons from the filament may enter. ...
The Feasibility of Domestic Medical Isotope Production for Clincal
... Nuclear medicine, a branch of medicine that involves the application of radioactive substances to diagnose and treat disease, has become an essential aspect of dozens of medical procedures. On any given day, countless patients are administered trace amounts of radioactive materials for the purpose o ...
... Nuclear medicine, a branch of medicine that involves the application of radioactive substances to diagnose and treat disease, has become an essential aspect of dozens of medical procedures. On any given day, countless patients are administered trace amounts of radioactive materials for the purpose o ...
Techniques to lower CT dose
... 1. Proper patient positioning on a CT scanner table is the first step to assure use of dose saving options. Higher noise images can occur when patients are not well centered in the scan field of view (FOV). By positioning the body at isocenter, the need to increase mA to compensate for the noise is ...
... 1. Proper patient positioning on a CT scanner table is the first step to assure use of dose saving options. Higher noise images can occur when patients are not well centered in the scan field of view (FOV). By positioning the body at isocenter, the need to increase mA to compensate for the noise is ...
section .2300 – criteria and standards for computed tomography
... to the beginning of the review period but which had been issued a certificate of need. ...
... to the beginning of the review period but which had been issued a certificate of need. ...
Essential Tips for Dental Radiographers
... 1. Review the Objectives: Objectives provide an overview of the entire course. 2. Read the course material. 3. Complete the test: a. Return to our website: www.dentallearning.org, click on Take the Exam, enter your answers, register, if you are new customer (existing customers login), pay for the co ...
... 1. Review the Objectives: Objectives provide an overview of the entire course. 2. Read the course material. 3. Complete the test: a. Return to our website: www.dentallearning.org, click on Take the Exam, enter your answers, register, if you are new customer (existing customers login), pay for the co ...
Artefacts in cone beam CT - Scientific Research Publishing
... a high energy X-ray photon and one of the outer shell electrons of an atom. This outer shell electron is bound with very little energy to the atom so when the X-ray photon collides with it, the electron is ejected from the atom. Because energy and momentum are both conserved in this collision, the e ...
... a high energy X-ray photon and one of the outer shell electrons of an atom. This outer shell electron is bound with very little energy to the atom so when the X-ray photon collides with it, the electron is ejected from the atom. Because energy and momentum are both conserved in this collision, the e ...
Conference Category
... • Although the carbon fiber head holder has minimal x-ray attenuation relative to metals, the shape/design of the CT head holder results in differing attenuation values based on the thickness of the carbon fiber that the x-ray beam must traverse. • CT head holder thickness is approximately 5mm, whi ...
... • Although the carbon fiber head holder has minimal x-ray attenuation relative to metals, the shape/design of the CT head holder results in differing attenuation values based on the thickness of the carbon fiber that the x-ray beam must traverse. • CT head holder thickness is approximately 5mm, whi ...
Flat detectors and their clinical applications
... should be maximized, the additive electronic noise generated during the numerous conversion and amplification steps is to be kept at a minimum. DQE (detective quantum efficiency) has evolved as the fundamental physical parameter describing the performance characteristics of an X-ray detector as it c ...
... should be maximized, the additive electronic noise generated during the numerous conversion and amplification steps is to be kept at a minimum. DQE (detective quantum efficiency) has evolved as the fundamental physical parameter describing the performance characteristics of an X-ray detector as it c ...
Basic Principles of Computed Axial Tomography
... of the relative merits of these algorithms is outside the scope of this work. The method of reconstruction which is currently used in most CT devices is conceptually quite simple. Called either the "convolution" or the "filtered back projection" reconstruction method, 5-7 it can be illustrated as fo ...
... of the relative merits of these algorithms is outside the scope of this work. The method of reconstruction which is currently used in most CT devices is conceptually quite simple. Called either the "convolution" or the "filtered back projection" reconstruction method, 5-7 it can be illustrated as fo ...
Assessment of absorbed dose in critical organs in OPG: a phantom
... three imaging centers, one digital and the remainders analogue. The absorbed dose to brain was measured globally with two vertically and horizontally embedded films in the phantom and submandibular, parotid and thyroid glands were also measured at their correct position in the phantom. The dose to t ...
... three imaging centers, one digital and the remainders analogue. The absorbed dose to brain was measured globally with two vertically and horizontally embedded films in the phantom and submandibular, parotid and thyroid glands were also measured at their correct position in the phantom. The dose to t ...
Improving digital image quality for larger patient sizes without
... Figure 7 Scatter-free image with noise (dose limitation), a limited number of X-ray photons is used to make an image. Therefore, a limited number of such photons reach each detector pixel. These quantized processes are governed by Poisson statistics. This means that the number of photons per pixel v ...
... Figure 7 Scatter-free image with noise (dose limitation), a limited number of X-ray photons is used to make an image. Therefore, a limited number of such photons reach each detector pixel. These quantized processes are governed by Poisson statistics. This means that the number of photons per pixel v ...
Basic CT Physics - Society for Pediatric Radiology
... CTDIvol Other Important things to remember about CTDIvol • The CTDIvol displayed on the scanner before the Topogram (ie. such as when you are building a protocol) will be only dependent on the technique and the phantom used (16cm or 32cm). Therefore, it will not accurately reflect the patient dose. ...
... CTDIvol Other Important things to remember about CTDIvol • The CTDIvol displayed on the scanner before the Topogram (ie. such as when you are building a protocol) will be only dependent on the technique and the phantom used (16cm or 32cm). Therefore, it will not accurately reflect the patient dose. ...
DRL Reference Guide - NC Radiation Protection
... Diagnostic Reference Level (DRL) is a dose metric for an average size patient or a phantom. Entrance Skin Air Kerma (ESAK) in radiography, Entrance Air Kerma Rate in fluoroscopy, and CT Dose Index (CTDIvol) in CT can be used as metric in a quality control program to identify possible situations wher ...
... Diagnostic Reference Level (DRL) is a dose metric for an average size patient or a phantom. Entrance Skin Air Kerma (ESAK) in radiography, Entrance Air Kerma Rate in fluoroscopy, and CT Dose Index (CTDIvol) in CT can be used as metric in a quality control program to identify possible situations wher ...
A cost effective and high fidelity fluoroscopy simulator
... target procedure is the voiding cystourethrography (VCUG) examination. The VCUG examination is a method for studying the bladder and urethra using x-ray fluoroscopy while the patient is voiding (urinating). It is commonly performed in children that experience recurring urinary tract infections, have ...
... target procedure is the voiding cystourethrography (VCUG) examination. The VCUG examination is a method for studying the bladder and urethra using x-ray fluoroscopy while the patient is voiding (urinating). It is commonly performed in children that experience recurring urinary tract infections, have ...
Diagnostic Reference Levels (DRL)
... Diagnostic Reference Level (DRL) is a dose metric for an average size patient or a phantom. CT Dose Index (CTDIvol) in CT can be used as a metric in a quality control program to identify possible situations where protocols, equipment, or procedures may be produce high radiation doses to patients. Th ...
... Diagnostic Reference Level (DRL) is a dose metric for an average size patient or a phantom. CT Dose Index (CTDIvol) in CT can be used as a metric in a quality control program to identify possible situations where protocols, equipment, or procedures may be produce high radiation doses to patients. Th ...
High-resolution investigation of spinal cord and spine
... success in small animal ex-vivo and in vivo models [33-36]. Micro-CT provides spatial resolution on micro-scale (5–50µm) (micro-CT) and nano-scale (~100 nanometres) (nano-CT) [35, 37-38] levels and micro-scale features can be readily resolved in opaque samples with dimensions measured from mm to cm ...
... success in small animal ex-vivo and in vivo models [33-36]. Micro-CT provides spatial resolution on micro-scale (5–50µm) (micro-CT) and nano-scale (~100 nanometres) (nano-CT) [35, 37-38] levels and micro-scale features can be readily resolved in opaque samples with dimensions measured from mm to cm ...
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.