American Society for Therapeutic Radiology and
... the spatial accuracy and precision of the simulation modality and the IGRT delivery. Steps must be taken to ensure that all aspects of simulation, including positioning, immobilization, and accounting for inherent organ motions, are properly carried out using IGRT in a consistent fashion. After the ...
... the spatial accuracy and precision of the simulation modality and the IGRT delivery. Steps must be taken to ensure that all aspects of simulation, including positioning, immobilization, and accounting for inherent organ motions, are properly carried out using IGRT in a consistent fashion. After the ...
RADIATION PROTECTION IN DIAGNOSTIC RADIOLOGY
... mechanical test because the distance imaged depends on couch speed and scanner software • One method of assessing distance accuracy is to use an acrylic test object containing two small radio-opaque markers, separated by a fixed distance (e.g., 20 cm) • The test object is scanned in Scan Projection ...
... mechanical test because the distance imaged depends on couch speed and scanner software • One method of assessing distance accuracy is to use an acrylic test object containing two small radio-opaque markers, separated by a fixed distance (e.g., 20 cm) • The test object is scanned in Scan Projection ...
How to Appropriately Calculate Effective Dose for CT
... ends, the calculation of patient population effective dose has become a popular tool for risk analysis and is further used to help convey associative effective dose values with other known or relatable population effective dose values (e.g., Nuclear Regulatory Com- ...
... ends, the calculation of patient population effective dose has become a popular tool for risk analysis and is further used to help convey associative effective dose values with other known or relatable population effective dose values (e.g., Nuclear Regulatory Com- ...
Electronic portal imaging devices: a review and
... By detecting the incident x-rays, the front plate acts as a build-up layer that generates highenergy electrons which expose the film. In addition, this front layer serves to block scattered secondary radiation incident on the cassette—radiation which would otherwise result in a loss of contrast. The ...
... By detecting the incident x-rays, the front plate acts as a build-up layer that generates highenergy electrons which expose the film. In addition, this front layer serves to block scattered secondary radiation incident on the cassette—radiation which would otherwise result in a loss of contrast. The ...
MSc Seferis
... Harris et al 2003). Furthermore Gd2O2S:Eu has been previously used as phosphor insert in phantoms for limited-angle x-ray luminescence tomography (XLT) (Carpenter et al 2011) and hybrid x-ray luminescence/optical imaging (Carpenter et al 2010). Previously, the image quality of a detector based on a ...
... Harris et al 2003). Furthermore Gd2O2S:Eu has been previously used as phosphor insert in phantoms for limited-angle x-ray luminescence tomography (XLT) (Carpenter et al 2011) and hybrid x-ray luminescence/optical imaging (Carpenter et al 2010). Previously, the image quality of a detector based on a ...
2011 SCCT guidelines on radiation dose and dose
... Coronary calcium scans should be performed with prospective ECG-triggered axial or prospective ECG-triggered helical techniques, a 120-kV tube potential, a patient size-adjusted tube current, and the widest beam collimation that allows for reconstruction of 3-mm slices. Considerations for coronary C ...
... Coronary calcium scans should be performed with prospective ECG-triggered axial or prospective ECG-triggered helical techniques, a 120-kV tube potential, a patient size-adjusted tube current, and the widest beam collimation that allows for reconstruction of 3-mm slices. Considerations for coronary C ...
pdf
... Although the underlying mechanism of contrast-induced nephropathy (CIN) is not fully understood, studies suggest that reduced renal blood flow induced by the CM may subsequently contribute to its nephrotoxic potential. Figure 2 demonstrates changes in the renal resistance index (RRI) after intra-art ...
... Although the underlying mechanism of contrast-induced nephropathy (CIN) is not fully understood, studies suggest that reduced renal blood flow induced by the CM may subsequently contribute to its nephrotoxic potential. Figure 2 demonstrates changes in the renal resistance index (RRI) after intra-art ...
The possibilities of reducing radiation dose and improve image
... effects are in example cataract, hair loss and erythema. The International Committee on Radiation Protection (ICRP) states that for doses of 100 mSv and higher, there is epidemiologic proven risk for radiation related cancer induction, and that there is no rational for assuming a low-dose threshold ...
... effects are in example cataract, hair loss and erythema. The International Committee on Radiation Protection (ICRP) states that for doses of 100 mSv and higher, there is epidemiologic proven risk for radiation related cancer induction, and that there is no rational for assuming a low-dose threshold ...
SERIES IAEA HUMAN HEALTH SERIES
... technological developments have brought about extensive increases in the use of this diagnostic tool generally, and in an increasing number of Member States. The complexity of this technology continues to increase, as does its potential to deliver substantial doses to patients. Consequently, the nee ...
... technological developments have brought about extensive increases in the use of this diagnostic tool generally, and in an increasing number of Member States. The complexity of this technology continues to increase, as does its potential to deliver substantial doses to patients. Consequently, the nee ...
- Braincon
... simultaneous visibility of the thinnest regions (cervical spine) as well as the thickest ones (scapula-thoracic area, lower lumbar spine, pelvis) (Fig. 5a, b). Absence of parallax explains the lack of distortion of the anatomical structures. At last, with an appropriate software and a ‘‘bone morphin ...
... simultaneous visibility of the thinnest regions (cervical spine) as well as the thickest ones (scapula-thoracic area, lower lumbar spine, pelvis) (Fig. 5a, b). Absence of parallax explains the lack of distortion of the anatomical structures. At last, with an appropriate software and a ‘‘bone morphin ...
View Presentation Document
... Bismuth shields are easy to use and have been shown to reduce dose to anterior organs in CT scanning . However, there are several disadvantages associated with the use of bismuth shields, especially when used with automatic exposure control or tube current modulation ...
... Bismuth shields are easy to use and have been shown to reduce dose to anterior organs in CT scanning . However, there are several disadvantages associated with the use of bismuth shields, especially when used with automatic exposure control or tube current modulation ...
CT Protocol Selection in PET-CT Imaging
... particularly for therapy assessment and clinical trials, correction steps are needed to account for contrast. 14 Many commercial systems offer corrections to reduce these errors, although they can lead to increased errors in other highly attenuating regions, such as bone, and at lower kVp settings. ...
... particularly for therapy assessment and clinical trials, correction steps are needed to account for contrast. 14 Many commercial systems offer corrections to reduce these errors, although they can lead to increased errors in other highly attenuating regions, such as bone, and at lower kVp settings. ...
High-dose MVCT image guidance for stereotactic body
... The ability to resolve contrast differences in an image is fundamentally limited by the number of photons detected during acquisition. If the number of photons is too small, noise will dominate the image—making the borders between different contrast regions indistinguishable. MV imaging systems are ...
... The ability to resolve contrast differences in an image is fundamentally limited by the number of photons detected during acquisition. If the number of photons is too small, noise will dominate the image—making the borders between different contrast regions indistinguishable. MV imaging systems are ...
Coregistered tomographic x-ray and optical breast imaging: initial
... X-ray imaging 共mammography兲 is currently the most widely accepted method for the diagnosis of breast lesions. Mammography screening is the most effective means of detecting early stage, nonpalpable breast cancers and has been shown clinically to reduce patient mortality through the early detection o ...
... X-ray imaging 共mammography兲 is currently the most widely accepted method for the diagnosis of breast lesions. Mammography screening is the most effective means of detecting early stage, nonpalpable breast cancers and has been shown clinically to reduce patient mortality through the early detection o ...
Innova X-ray Dose Efficiency: Objective Evidence
... In evaluating any scientific study of a complex subject, it is important to assess the clarity of the objectives and metrics, the methods for managing confounding factors, and the strength of the objective evidence to support the conclusions. In the case of studies of patient dose in interventional ...
... In evaluating any scientific study of a complex subject, it is important to assess the clarity of the objectives and metrics, the methods for managing confounding factors, and the strength of the objective evidence to support the conclusions. In the case of studies of patient dose in interventional ...
Diagnostic Reference Levels in Medical Imaging
... patient tissue doses that determine the relative patient risk, the following considerations are important: (a) The numerical value of the diagnostic reference level should be tied to defined clinical and technical requirements for the medical imaging task. A selected numerical value for one situatio ...
... patient tissue doses that determine the relative patient risk, the following considerations are important: (a) The numerical value of the diagnostic reference level should be tied to defined clinical and technical requirements for the medical imaging task. A selected numerical value for one situatio ...
Chapter 5 Treatment Machines for External Beam - Phy428-528
... • The main characteristics of the Coolidge tube are its high vacuum and its use of heated filament (cathode). • The heated filament emits electrons through thermionic emission. • X rays are produced in the target (anode) through radiation losses of electrons producing characteristic and bremsstrahlu ...
... • The main characteristics of the Coolidge tube are its high vacuum and its use of heated filament (cathode). • The heated filament emits electrons through thermionic emission. • X rays are produced in the target (anode) through radiation losses of electrons producing characteristic and bremsstrahlu ...
X-ray detectors for digital radiography
... Some of the factors to be considered here are the ‘dead regions’ that may exist within and around the edges of the detector. In an electronic detector used for digital radiography, these might be required for routing of wire leads or placement of auxiliary detector components such as buffers, clocks ...
... Some of the factors to be considered here are the ‘dead regions’ that may exist within and around the edges of the detector. In an electronic detector used for digital radiography, these might be required for routing of wire leads or placement of auxiliary detector components such as buffers, clocks ...
Sir Godfrey Newbold Hounsfield KT CBE. 28 August 1919
... grasp the sensitivity. They said, so what? They couldn’t understand that they would be seeing much more. The result was very discouraging.’ The view of the Board at EMI was that the talk was of a machine that would cost a hundred thousand pounds, that had not actually yet been built and for which th ...
... grasp the sensitivity. They said, so what? They couldn’t understand that they would be seeing much more. The result was very discouraging.’ The view of the Board at EMI was that the talk was of a machine that would cost a hundred thousand pounds, that had not actually yet been built and for which th ...
j32-2003-ieeetmi-gradient
... minimizes the sum of distances is known [32]. In practice, robustness is achieved by first performing coarse registration with landmarks followed by fine registration with surfaces. Commercial systems rely on implanted fiducials and on “cloud of points” to perform the registration. Geometry-based re ...
... minimizes the sum of distances is known [32]. In practice, robustness is achieved by first performing coarse registration with landmarks followed by fine registration with surfaces. Commercial systems rely on implanted fiducials and on “cloud of points” to perform the registration. Geometry-based re ...
Diagnostic Reference Levels Based on Latest Surveys in Japan
... overcome potentially life-threatening diseases; therefore, the application of radiological procedures should be judged on a case-by-case basis rather than by applying uniform standards, such as dose limits. However, in actual practice, the top priority is to solve the health problems of the patient, ...
... overcome potentially life-threatening diseases; therefore, the application of radiological procedures should be judged on a case-by-case basis rather than by applying uniform standards, such as dose limits. However, in actual practice, the top priority is to solve the health problems of the patient, ...
AAPM Medical Physics Practice Guideline 1.a: CT Protocol
... may vary, depending on the type of facility being supported; regardless, the QMP must be involved in the review of all protocols. These considerations should be balanced with adequate response times to facility inquiries. A QMP’s time at a facility should include but not be limited to: a. meeting ...
... may vary, depending on the type of facility being supported; regardless, the QMP must be involved in the review of all protocols. These considerations should be balanced with adequate response times to facility inquiries. A QMP’s time at a facility should include but not be limited to: a. meeting ...
X-ray scattering in full-field digital mammography
... of mammograms. However, x-ray scattering decreases contrast resolution in an image, as discussed by Barnes.12 Contrast resolution is defined as the relative difference of an object signal level compared to the background signal. The greater the signal step, the better the contrast of the imaged obje ...
... of mammograms. However, x-ray scattering decreases contrast resolution in an image, as discussed by Barnes.12 Contrast resolution is defined as the relative difference of an object signal level compared to the background signal. The greater the signal step, the better the contrast of the imaged obje ...
Image-guided radiation therapy (IGRT): practical
... IGRT system The components of any IGRT system are the follows: • An image acquisition system. • A set of reference images for comparison. • A software for the comparison match between reference images and CT planning. • A protocol that defines the correction method. Two kinds of procedures are u ...
... IGRT system The components of any IGRT system are the follows: • An image acquisition system. • A set of reference images for comparison. • A software for the comparison match between reference images and CT planning. • A protocol that defines the correction method. Two kinds of procedures are u ...
Backscatter X-ray
Backscatter X-ray is an advanced X-ray imaging technology. Traditional X-ray machines detect hard and soft materials by the variation in transmission through the target. In contrast, backscatter X-ray detects the radiation that reflects from the target. It has potential applications where less-destructive examination is required, and can be used if only one side of the target is available for examination.The technology is one of two types of whole body imaging technologies that have been used to perform full-body scans of airline passengers to detect hidden weapons, tools, liquids, narcotics, currency, and other contraband. A competing technology is millimeter wave scanner. An airport security machine of this type is also referred to as ""body scanner"", ""whole body imager (WBI)"", ""security scanner"", and ""naked scanner"".