Radiation dose reduction in computed tomography
... tuation in the electronic components of the data acquisition system. When the number of photons is reduced to the level where the detected signal is as small as signal from electronic noise, the images will have significantly degraded quality. Photon starvation artifacts occur in low-dose sit‑ uatio ...
... tuation in the electronic components of the data acquisition system. When the number of photons is reduced to the level where the detected signal is as small as signal from electronic noise, the images will have significantly degraded quality. Photon starvation artifacts occur in low-dose sit‑ uatio ...
Blunt Pancreatic Trauma: The Diagnostic Role of MDCT
... Dawson AR, Webster CH, Howe HC, Theron EJ, Meiring L. Rupture of the head of the pancreas by blunt trauma: a case report. S Afr Med J 1985; 67:560‐562. Jones RC. Management of pancreatic trauma. Am J Surg 1985;150:698–704. Davis JJ, Cohn I, Nance FC. Diagnosis and treatment of blunt abdominal trau ...
... Dawson AR, Webster CH, Howe HC, Theron EJ, Meiring L. Rupture of the head of the pancreas by blunt trauma: a case report. S Afr Med J 1985; 67:560‐562. Jones RC. Management of pancreatic trauma. Am J Surg 1985;150:698–704. Davis JJ, Cohn I, Nance FC. Diagnosis and treatment of blunt abdominal trau ...
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 ...
Quality assurance for image-guided radiation therapy
... are in the range of 2 to 10 mSv,27 imaging doses typically can be reduced further by a factor of 2–4 when used for daily targeting.28 This is because the image quality from low-dose CT imaging is sufficient for image alignment. II.B. Kilovoltage cone-beam CT ...
... are in the range of 2 to 10 mSv,27 imaging doses typically can be reduced further by a factor of 2–4 when used for daily targeting.28 This is because the image quality from low-dose CT imaging is sufficient for image alignment. II.B. Kilovoltage cone-beam CT ...
Effects of breathing and cardiac motion on spatial resolution in the
... either the ventilation or the cardiac triggers. However, instead of acquiring a single line of Fourier space on each acquisition (as performed in MRI), we acquired 2D radiographic projections. Two different gating methods were used: ventilation synchronous exposures without cardiac gating, and venti ...
... either the ventilation or the cardiac triggers. However, instead of acquiring a single line of Fourier space on each acquisition (as performed in MRI), we acquired 2D radiographic projections. Two different gating methods were used: ventilation synchronous exposures without cardiac gating, and venti ...
Practice Guideline for Determinants of Image Quality in Digital
... acquisition, display, and storage aspects of the process. Basic clinical guidelines are a subset, and all interested individuals are encouraged to review the information with this in mind. Additionally, this guideline includes the input from industry, radiologists and other interested parties in an ...
... acquisition, display, and storage aspects of the process. Basic clinical guidelines are a subset, and all interested individuals are encouraged to review the information with this in mind. Additionally, this guideline includes the input from industry, radiologists and other interested parties in an ...
Image Guided Radiation Therapy: A Refresher
... Presenter has a financial interest in some of the imaging technology reported here and research collaborations with Elekta Elekta, Philips Philips, IMRIS, Modus Medical, and Raysearch. Results from studies using investigational devices will be described in this presentation. ...
... Presenter has a financial interest in some of the imaging technology reported here and research collaborations with Elekta Elekta, Philips Philips, IMRIS, Modus Medical, and Raysearch. Results from studies using investigational devices will be described in this presentation. ...
Cone Beam Computed Tomography
... Diagnostic radiology has undergone profound changes in the last 30 years. New technologies are available to the dental field, cone beam computed tomography (CBCT) as one of the most important. CBCT is a catch-all term for a technology comprising a variety of machines differing in many respects: pati ...
... Diagnostic radiology has undergone profound changes in the last 30 years. New technologies are available to the dental field, cone beam computed tomography (CBCT) as one of the most important. CBCT is a catch-all term for a technology comprising a variety of machines differing in many respects: pati ...
Breakthrough Technology Expanding the Potential in
... research project. This project will define tomorrow’s leading edge cancer treatment systems. These Elekta Synergy™ systems will have the potential to expand the use of radiation medicine by delivering cancer tumor targeting via a new integrated 3-dimensional imaging system Elekta has an enviable tra ...
... research project. This project will define tomorrow’s leading edge cancer treatment systems. These Elekta Synergy™ systems will have the potential to expand the use of radiation medicine by delivering cancer tumor targeting via a new integrated 3-dimensional imaging system Elekta has an enviable tra ...
The Benefits of Moving up to Multislice CT
... postprocessing tools, unimaginable just a few years ago, have placed multislice CT into the radiology spotlight. These advances have led to important medical insights and opened up dramatic new horizons in the research, diagnosis, and treatment of disease. Since its introduction in 1972, CT has been ...
... postprocessing tools, unimaginable just a few years ago, have placed multislice CT into the radiology spotlight. These advances have led to important medical insights and opened up dramatic new horizons in the research, diagnosis, and treatment of disease. Since its introduction in 1972, CT has been ...
Transmission and emission x-ray microscopy: operation modes
... in terms of spatial resolution, combined with chemical and morphology sensitivity, to analyze solid, soft and liquid matter. The advent of ultrabright third and fourth generation photon sources and continuous development of x-ray optics and detectors has pushed the limits of imaging and spectroscopi ...
... in terms of spatial resolution, combined with chemical and morphology sensitivity, to analyze solid, soft and liquid matter. The advent of ultrabright third and fourth generation photon sources and continuous development of x-ray optics and detectors has pushed the limits of imaging and spectroscopi ...
Contents
... The EPID studied in this work is a Varian aS1000 (Varian Medical Systems). It is mounted with a retractable robotic arm (the ExactArm) on a Varian Clinac 2100CD linear accelerator (figure 1). The accelerator is capable of delivering 6 MV and 18 MV photons as well as electrons of several energies fro ...
... The EPID studied in this work is a Varian aS1000 (Varian Medical Systems). It is mounted with a retractable robotic arm (the ExactArm) on a Varian Clinac 2100CD linear accelerator (figure 1). The accelerator is capable of delivering 6 MV and 18 MV photons as well as electrons of several energies fro ...
Does Iterative Reconstruction Improve Image Quality and Reduce
... for the shape and size of detector cells and voxels, as well as neglecting the image noise resulting from Poisson statistical variations of x-ray photons.8 As a result, there is a need for alternative algorithms that model the CT system more accurately, in order to produce diagnostic images while ma ...
... for the shape and size of detector cells and voxels, as well as neglecting the image noise resulting from Poisson statistical variations of x-ray photons.8 As a result, there is a need for alternative algorithms that model the CT system more accurately, in order to produce diagnostic images while ma ...
A New Way for Multidimensional Medical Data Management
... image databases, which enable access to a patient’s historical data, including multidimensional medical images from previous examinations and the opportunity for statistical and comparative image analyses, are key components in preventive medicine and future diagnosis [4], [5]. However, these medica ...
... image databases, which enable access to a patient’s historical data, including multidimensional medical images from previous examinations and the opportunity for statistical and comparative image analyses, are key components in preventive medicine and future diagnosis [4], [5]. However, these medica ...
Multislice Computed Tomography: Basic Principles and Clinical
... contrast) which are strongly inhomogeneous in axial direction. A demanding example is the base of the skull with bony structures abruptly ending in an image plane. Phantom studies have shown that a larger pitch and narrower collimation is much more favorable for suppressing artifacts than a lower p ...
... contrast) which are strongly inhomogeneous in axial direction. A demanding example is the base of the skull with bony structures abruptly ending in an image plane. Phantom studies have shown that a larger pitch and narrower collimation is much more favorable for suppressing artifacts than a lower p ...
Panoramic Radiography Tips
... and surrounding structures, the facial bones and condyles, and parts of the maxillary sinus and nasal complexes. The equipment used to obtain panoramic radiographs has continued to improve with recent advances including automatic exposure and multiple image programs. However, to achieve a diagnostic ...
... and surrounding structures, the facial bones and condyles, and parts of the maxillary sinus and nasal complexes. The equipment used to obtain panoramic radiographs has continued to improve with recent advances including automatic exposure and multiple image programs. However, to achieve a diagnostic ...
Cone beam-computed tomography applications in endodontics: A
... systems for VRF diagnosis and concluded that CAT I and Scannora 3D are the most accurate devices, respectively.[33] He reported that what make these two machines different from other ones were their detectors. I-CAT and Scannora have image intensifier tube/charged coupled device while other three dev ...
... systems for VRF diagnosis and concluded that CAT I and Scannora 3D are the most accurate devices, respectively.[33] He reported that what make these two machines different from other ones were their detectors. I-CAT and Scannora have image intensifier tube/charged coupled device while other three dev ...
SOMATOM Definition AS
... combination of outstanding image quality and patient-centric productivity is the lever to maximize your clinical outcome. ...
... combination of outstanding image quality and patient-centric productivity is the lever to maximize your clinical outcome. ...
Lecture 10 Mammography Thur - International Atomic Energy Agency
... contrast falls below 0.1 for energies above 27 keV ...
... contrast falls below 0.1 for energies above 27 keV ...
Title Spatial resolution measurement for iterative
... of image quality in CT, and high-contrast objects such as metal wires and high-contrast periodic patterns are required for obtaining accurate results with the conventional measurement method [11]. Although there are some reports regarding the image quality of IRs, in which the resolution properties ...
... of image quality in CT, and high-contrast objects such as metal wires and high-contrast periodic patterns are required for obtaining accurate results with the conventional measurement method [11]. Although there are some reports regarding the image quality of IRs, in which the resolution properties ...
Radiation Safety
... Bone densitometry uses an enhanced form of x-ray technology (dual-energy x-ray absorptiometry, or DEXA) to measure bone mineral density and diagnose osteoporosis. Computed tomography (CT or CAT scan) uses special equipment to obtain x-ray image data from different angles around the body. A computer ...
... Bone densitometry uses an enhanced form of x-ray technology (dual-energy x-ray absorptiometry, or DEXA) to measure bone mineral density and diagnose osteoporosis. Computed tomography (CT or CAT scan) uses special equipment to obtain x-ray image data from different angles around the body. A computer ...
File - Dentistry Notes
... In panoramic radiography, the focal trough is a theoretical concept used to determine where the dental arches must be positioned to achieve the clearest image. The focal trough can be defined as a three-dimensional curved zone in which structures are clearly demonstrated on a panoramic radiograph. T ...
... In panoramic radiography, the focal trough is a theoretical concept used to determine where the dental arches must be positioned to achieve the clearest image. The focal trough can be defined as a three-dimensional curved zone in which structures are clearly demonstrated on a panoramic radiograph. T ...
Fluoroscopy
Fluoroscopy /flɔrˈɒskəpi/ is an imaging technique that uses X-rays to obtain real-time moving images of the interior of an object. In its primary application of medical imaging, a fluoroscope /ˈflɔrɵˌskoʊp/ allows a physician to see the internal structure and function of a patient, so that the pumping action of the heart or the motion of swallowing, for example, can be watched. This is useful for both diagnosis and therapy and occurs in general radiology, interventional radiology, and image-guided surgery. In its simplest form, a fluoroscope consists of an X-ray source and a fluorescent screen, between which a patient is placed. However, since the 1950s most fluoroscopes have included X-ray image intensifiers and cameras as well, to improve the image's visibility and make it available on a remote display screen. For many decades fluoroscopy tended to produce live pictures that were not recorded, but since the 1960s, as technology improved, recording and playback became the norm.Fluoroscopy is similar to radiography and X-ray computed tomography (X-ray CT) in that it generates images using X-rays. The original difference was that radiography fixed still images on film whereas fluoroscopy provided live moving pictures that were not stored. However, today radiography, CT, and fluoroscopy are all digital imaging modes with image analysis software and data storage and retrieval. The use of X-rays, a form of ionizing radiation, requires the potential risks from a procedure to be carefully balanced with the benefits of the procedure to the patient. Because the patient must be exposed to a continuous source of x-rays instead of a momentary pulse, a fluoroscopy procedure generally subjects a patient to a higher absorbed dose of radiation than an ordinary (still) radiograph. Much research has been directed toward reducing radiation exposure, and recent advances in fluoroscopy technology such as digital image processing and flat panel detectors, have resulted in much lower radiation doses than former procedures.The type of fluoroscopy used in airport security (to check for hidden weapons or bombs) uses lower doses of radiation than medical fluoroscopy. It was formerly also used in retail stores in the form of shoe-fitting fluoroscopes, but such use was discontinued because it is no longer considered acceptable to use radiation exposure, however small the dose, for nonessential purposes. Only important applications such as health care, bodily safety, food safety, nondestructive testing, and scientific research meet the risk-benefit threshold for use. The reason for higher doses in medical applications is that they are more demanding about tissue contrast, and for the same reason they sometimes require contrast media.