Computed tomography – an increasing source of radiation exposure
... survivors who received low doses of radiation, ranging from 5 to 150 mSv27-29; the mean dose in this subgroup was about 40 mSv, which approximates the relevant organ dose from a typical CT study involving two or three scans in an adult. Although most of the quantitative estimates of the radiation-in ...
... survivors who received low doses of radiation, ranging from 5 to 150 mSv27-29; the mean dose in this subgroup was about 40 mSv, which approximates the relevant organ dose from a typical CT study involving two or three scans in an adult. Although most of the quantitative estimates of the radiation-in ...
Radiology
... Under local anesthesia, a needle is placed into lower lumbar spinal canal, and then CSF flow is confirmed. Contrast medium is then injected which mixes with CSF around spinal cord, making it visible on x-ray images Often a CT scan is also performed after this May be performed when MRI is contraindic ...
... Under local anesthesia, a needle is placed into lower lumbar spinal canal, and then CSF flow is confirmed. Contrast medium is then injected which mixes with CSF around spinal cord, making it visible on x-ray images Often a CT scan is also performed after this May be performed when MRI is contraindic ...
ST HELENS + KNOWSLEY NHS TEACHING HOSPITAL TRUST
... The RPA must provide a formal training course for at least two people on an annual basis to enable key staff to be able to fulfil the requirements of the Radiation Protection Supervisor role, and also regular updates for these staff. There is also a need to provide training in the safe use of medica ...
... The RPA must provide a formal training course for at least two people on an annual basis to enable key staff to be able to fulfil the requirements of the Radiation Protection Supervisor role, and also regular updates for these staff. There is also a need to provide training in the safe use of medica ...
Medical Physics: Some Recollections in Diagnostic X
... devices, scintillation cameras, ultrasonographic (US) devices, advanced high capacity x-ray tubes, and rapid film processors (1). However, maturation of the computer has accelerated even more and enabled technology such as computed tomography (CT), magnetic resonance (MR) imaging, and sophisticated ...
... devices, scintillation cameras, ultrasonographic (US) devices, advanced high capacity x-ray tubes, and rapid film processors (1). However, maturation of the computer has accelerated even more and enabled technology such as computed tomography (CT), magnetic resonance (MR) imaging, and sophisticated ...
printable version - Environment, Health and Safety
... Diagnostic Radiopharmaceuticals (such as Tc-99m, F-18, Tl-201, I-131, and I-125) are used in Nuclear Medicine for diagnostic procedures and emit gamma rays, which are a penetrating radiation, like x-rays. These radionuclides remain in the patient after the study is over, but have short half-lives, s ...
... Diagnostic Radiopharmaceuticals (such as Tc-99m, F-18, Tl-201, I-131, and I-125) are used in Nuclear Medicine for diagnostic procedures and emit gamma rays, which are a penetrating radiation, like x-rays. These radionuclides remain in the patient after the study is over, but have short half-lives, s ...
EFFICIENT QUALITY ASSURANCE PROGRAMS IN RADIOLOGY
... A review of the last six years QC on digital radiography systems in our region show that most divergences are found (% of reported divergences) on the alignment and centring of radiation field size and position (37%), automatic exposure control, AEC (24%), grid related problems (16%) and image artef ...
... A review of the last six years QC on digital radiography systems in our region show that most divergences are found (% of reported divergences) on the alignment and centring of radiation field size and position (37%), automatic exposure control, AEC (24%), grid related problems (16%) and image artef ...
Presentation(in MS PowerPointFormat)
... “So excited was the public that each newly radiographed organ or system brought headlines. With everything about the rays so novel, it is easy to understand the frequent appearance of falsified images, such as this much-admired "first radiograph of the human brain," in reality a pan of cat intestine ...
... “So excited was the public that each newly radiographed organ or system brought headlines. With everything about the rays so novel, it is easy to understand the frequent appearance of falsified images, such as this much-admired "first radiograph of the human brain," in reality a pan of cat intestine ...
Ten Steps to Image Gently
... increases the risk of cancer • For an indicated CT scan, the likely benefit is far greater than the estimated risk • Clinicians and radiologists should work together to make the population exposure ALARA ...
... increases the risk of cancer • For an indicated CT scan, the likely benefit is far greater than the estimated risk • Clinicians and radiologists should work together to make the population exposure ALARA ...
Gold Nanoparticle Contrast Agents in Advanced X
... diffracted X-rays are detected at each scan position, thereby it maps out the chemical, elemental or crystallographic phase properties of the specimen. Considering the requirements for high-intensity X-ray beams, the use of scanning X-ray microscopes is limited to synchrotron radiation laboratories. ...
... diffracted X-rays are detected at each scan position, thereby it maps out the chemical, elemental or crystallographic phase properties of the specimen. Considering the requirements for high-intensity X-ray beams, the use of scanning X-ray microscopes is limited to synchrotron radiation laboratories. ...
An Imaging Process for Early Detection of Colorectal Cancer Using
... Even in the case of the above mentioned incidents the doses can be compared to doses received by patients in conventional diagnostic radiology. The maximal effective dose received in case of a serious incident where the capsule remains nested on the colon wall for the remainder of the patient's lif ...
... Even in the case of the above mentioned incidents the doses can be compared to doses received by patients in conventional diagnostic radiology. The maximal effective dose received in case of a serious incident where the capsule remains nested on the colon wall for the remainder of the patient's lif ...
Acceptability requirements for X-ray equipment used in health care
... The acceptability requirements denote the minimum requirements or acceptability limits that are imposed on the performance characteristics of the equipment when it is used. No later than at the time the equipment no longer meets an acceptability limit, the equipment must be repaired in a way that re ...
... The acceptability requirements denote the minimum requirements or acceptability limits that are imposed on the performance characteristics of the equipment when it is used. No later than at the time the equipment no longer meets an acceptability limit, the equipment must be repaired in a way that re ...
Optimal Tube Potential in Pediatric CT for Radiation
... We refined the reduced-kV technique chart clinically in order to take into account the potential benefit of increased iodine contrast enhancement at lower kV settings. Using the technique chart from Step 2, 33 pediatric body cases acquired with the reduced-kV techniques were collected (17 with 80 kV ...
... We refined the reduced-kV technique chart clinically in order to take into account the potential benefit of increased iodine contrast enhancement at lower kV settings. Using the technique chart from Step 2, 33 pediatric body cases acquired with the reduced-kV techniques were collected (17 with 80 kV ...
Computed tomography--an increasing source of radiation exposure.
... survivors who received low doses of radiation, ranging from 5 to 150 mSv27-29; the mean dose in this subgroup was about 40 mSv, which approximates the relevant organ dose from a typical CT study involving two or three scans in an adult. Although most of the quantitative estimates of the radiation-in ...
... survivors who received low doses of radiation, ranging from 5 to 150 mSv27-29; the mean dose in this subgroup was about 40 mSv, which approximates the relevant organ dose from a typical CT study involving two or three scans in an adult. Although most of the quantitative estimates of the radiation-in ...
Selective Internal Radiation Therapy
... other sites of metastasis that have spread through the body – even if they are yet to be detected with diagnostic imaging • Beta’s have the additional feature of the “bystander effect” – they will kill adjacent tumour cells, even if these cells lack the specific tumour-associated antigen or receptor ...
... other sites of metastasis that have spread through the body – even if they are yet to be detected with diagnostic imaging • Beta’s have the additional feature of the “bystander effect” – they will kill adjacent tumour cells, even if these cells lack the specific tumour-associated antigen or receptor ...
Recommended Core Curriculum
... 1) the physical description, random nature, and energy dependence of the five scatter and absorption interactions that x-ray photons undergo with individual atoms (coherent scatter, photoelectric effect, compton effect, pair production, and photonuclear disintegration). 2) definitions of the key ter ...
... 1) the physical description, random nature, and energy dependence of the five scatter and absorption interactions that x-ray photons undergo with individual atoms (coherent scatter, photoelectric effect, compton effect, pair production, and photonuclear disintegration). 2) definitions of the key ter ...
Computed tomography: Are we aware of radiation risks in computed
... of higher radiation doses to children for a given CT examination and more importantly, the much larger lifetime risks per unit dose of radiation that apply to children, result in lifetime cancer mortality attributable to the radiation exposure from CT that is significantly higher in children than in ...
... of higher radiation doses to children for a given CT examination and more importantly, the much larger lifetime risks per unit dose of radiation that apply to children, result in lifetime cancer mortality attributable to the radiation exposure from CT that is significantly higher in children than in ...
RADIATION PROTECTION IN PEDIATRIC RADIOGRAPHY
... use the appropriate positioning of the child, when using immobilization tools, without affecting the diagnostic purpose of the imagining. (Fig. 1c and 1d; Fig. 2c; Fig. 3b). The quality of immobilization instruments has to be regularly checked to ensure their proper functioning, so that they are saf ...
... use the appropriate positioning of the child, when using immobilization tools, without affecting the diagnostic purpose of the imagining. (Fig. 1c and 1d; Fig. 2c; Fig. 3b). The quality of immobilization instruments has to be regularly checked to ensure their proper functioning, so that they are saf ...
Abstract
... The question then is: how far can we push the resolution of hard-x-ray images of biological samples? Recently, using high definition x-ray zone plates microradiology reached 60 nm resolution with first order diffraction and 30nm with third order diffraction (10, 11). We applied this approach to imag ...
... The question then is: how far can we push the resolution of hard-x-ray images of biological samples? Recently, using high definition x-ray zone plates microradiology reached 60 nm resolution with first order diffraction and 30nm with third order diffraction (10, 11). We applied this approach to imag ...
Cone Beam 3D Imaging
... to excellence and quality. QR s.r.l. is based in Italy and all NewTom products are designed and manufactured at our factory in Verona. Our products represent the Italian tradition of specialized manufacturing and NewTom is known all over the world for its reliability, high standards and state-of-the ...
... to excellence and quality. QR s.r.l. is based in Italy and all NewTom products are designed and manufactured at our factory in Verona. Our products represent the Italian tradition of specialized manufacturing and NewTom is known all over the world for its reliability, high standards and state-of-the ...
Radiation Protection and Performance Evaluation of PET-CT
... 2.3.3.1 A radiation warning sign complying with the IAEA safety standards regulation must be displayed on the outside of the entry doors to any room housing a PET-CT scanner. 2.3.3.2 A radiation warning light must be positioned at the entry doors to a room housing a PET-CT scanner. 2.3.3.3 Where a r ...
... 2.3.3.1 A radiation warning sign complying with the IAEA safety standards regulation must be displayed on the outside of the entry doors to any room housing a PET-CT scanner. 2.3.3.2 A radiation warning light must be positioned at the entry doors to a room housing a PET-CT scanner. 2.3.3.3 Where a r ...
Fun Dx Penguine Points
... -when the CT is calibrated, there should be a straight line through 0 -uniformity is the concept that when water is imaged, all of the pixel values must be equal, even if they are not consistent from 1 hour to the next -linear interpolation at 180 degrees improves z-axis resolution -wider multislice ...
... -when the CT is calibrated, there should be a straight line through 0 -uniformity is the concept that when water is imaged, all of the pixel values must be equal, even if they are not consistent from 1 hour to the next -linear interpolation at 180 degrees improves z-axis resolution -wider multislice ...
CT Radiation Dose Reduction by Modifying Primary Factors
... Fig 2. Transverse abdominal CT images acquired at tube current–time product levels of 200, 150, 100, and 50 mAs, with the remaining scan parameters held constant. Left renal cyst (white arrow) measuring 2 cm is seen at all 4 radiation dose levels. However, conspicuity of small liver vessels (black a ...
... Fig 2. Transverse abdominal CT images acquired at tube current–time product levels of 200, 150, 100, and 50 mAs, with the remaining scan parameters held constant. Left renal cyst (white arrow) measuring 2 cm is seen at all 4 radiation dose levels. However, conspicuity of small liver vessels (black a ...
3D X-ray Angiography 1
... By adding out-of-plane detectors, more projections can be obtained with each rotation of the CT gantry. Current clinical systems have as many as 16 rows of detectors. In addition, by rotating an x-ray-II system about the patient while contrast flows through the vessels being imaged, the entire vascu ...
... By adding out-of-plane detectors, more projections can be obtained with each rotation of the CT gantry. Current clinical systems have as many as 16 rows of detectors. In addition, by rotating an x-ray-II system about the patient while contrast flows through the vessels being imaged, the entire vascu ...
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.