Evaluation of absorbed dose and image quality in mammography
... evidence from clinical trials, that mammographic screening can reduce the breast cancer mortality with about 30%. The side effects include a small and age related risk of carcinogenesis due to the exposure of the glandular tissues in the breast to ionising radiation. As for all X-ray examinations, a ...
... evidence from clinical trials, that mammographic screening can reduce the breast cancer mortality with about 30%. The side effects include a small and age related risk of carcinogenesis due to the exposure of the glandular tissues in the breast to ionising radiation. As for all X-ray examinations, a ...
U.S. Exposures Limits: A History of Their Creation
... ■ The exposure conditions can be shown by appropriate techniques to produce SARs below 0.08 W/kg, as averaged over the whole body, and spatial peak SAR values not exceeding 1.6 W/kg, as averaged over any 1 g of tissue (defined as a tissue volume in the shape of a cube), except for the hands, wris ...
... ■ The exposure conditions can be shown by appropriate techniques to produce SARs below 0.08 W/kg, as averaged over the whole body, and spatial peak SAR values not exceeding 1.6 W/kg, as averaged over any 1 g of tissue (defined as a tissue volume in the shape of a cube), except for the hands, wris ...
The management of imaging dose during image-guided
... 共Received 8 January 2007; revised 5 July 2007; accepted for publication 22 July 2007; published 26 September 2007兲 Radiographic image guidance has emerged as the new paradigm for patient positioning, target localization, and external beam alignment in radiotherapy. Although widely varied in modality ...
... 共Received 8 January 2007; revised 5 July 2007; accepted for publication 22 July 2007; published 26 September 2007兲 Radiographic image guidance has emerged as the new paradigm for patient positioning, target localization, and external beam alignment in radiotherapy. Although widely varied in modality ...
The management of imaging dose during image-guided
... 共Received 8 January 2007; revised 5 July 2007; accepted for publication 22 July 2007; published 26 September 2007兲 Radiographic image guidance has emerged as the new paradigm for patient positioning, target localization, and external beam alignment in radiotherapy. Although widely varied in modality ...
... 共Received 8 January 2007; revised 5 July 2007; accepted for publication 22 July 2007; published 26 September 2007兲 Radiographic image guidance has emerged as the new paradigm for patient positioning, target localization, and external beam alignment in radiotherapy. Although widely varied in modality ...
Reducing Radiation Dose to the Female Breast During
... A database quantifying organ dose for several radiosensitive organs irradiated during CTCA, including the breast, was generated using Monte Carlo simulations. This database facilitates estimation of organ-specific dose deposited during CTCA protocols using arbitrary x-ray spectra or tube-current mod ...
... A database quantifying organ dose for several radiosensitive organs irradiated during CTCA, including the breast, was generated using Monte Carlo simulations. This database facilitates estimation of organ-specific dose deposited during CTCA protocols using arbitrary x-ray spectra or tube-current mod ...
Cone Beam Computed Tomography (CBCT) Dosimetry
... CBCT scan procedures, while the film calibrations were performed by 0 degree fixed irradiations ................................................................................................. 64 16. CBCT irradiation setups with extended CT phantoms simulated in the MC systems - (a) head phantom an ...
... CBCT scan procedures, while the film calibrations were performed by 0 degree fixed irradiations ................................................................................................. 64 16. CBCT irradiation setups with extended CT phantoms simulated in the MC systems - (a) head phantom an ...
PART I TORT LIABILITY AND RADIATION INJURIES
... nuclear reactor or in the detonation of an atomic bomb, neutrons become highly dangerous. They have great penetrating power and can make other substances radioactive. Each of the foregoing types of radiation can be injurious to persons or property under certain circumstances. This study will be conc ...
... nuclear reactor or in the detonation of an atomic bomb, neutrons become highly dangerous. They have great penetrating power and can make other substances radioactive. Each of the foregoing types of radiation can be injurious to persons or property under certain circumstances. This study will be conc ...
AAPM REPORT NO. 54 STEREOTACTIC RADIOSURGERY Report
... SRS was first developed by Leksell in the late 1940s to destroy dysfulLctional loci in the brain using orthovohage x rays (Leksell, 1951). Heavy charged panicles, gamma rays, and megavoltage x rays have been used in the intervening decades to irradiate arteriovenous malformations as well as benign a ...
... SRS was first developed by Leksell in the late 1940s to destroy dysfulLctional loci in the brain using orthovohage x rays (Leksell, 1951). Heavy charged panicles, gamma rays, and megavoltage x rays have been used in the intervening decades to irradiate arteriovenous malformations as well as benign a ...
Patient and Staff Radiological Protection in Cardiology
... cardiologists and support staff working in catheterization laboratories have found a high percentage of lens opacities attributable to occupational radiation exposure when radiological protection tools have not been used properly. 2. Principles of Radiological Protection for Patients and Staff The C ...
... cardiologists and support staff working in catheterization laboratories have found a high percentage of lens opacities attributable to occupational radiation exposure when radiological protection tools have not been used properly. 2. Principles of Radiological Protection for Patients and Staff The C ...
The Modern Technology of Radiation Oncology, Vol. 1
... body of each chapter is written at a level understandable by medical physicists and radiation oncologists, additional detailed information for medical physicists is provided in the appendices at the end of some of the chapters. As the title indicates, the book is primarily intended for medical physi ...
... body of each chapter is written at a level understandable by medical physicists and radiation oncologists, additional detailed information for medical physicists is provided in the appendices at the end of some of the chapters. As the title indicates, the book is primarily intended for medical physi ...
A Guide to CT Radiation Dose Management
... radiosensitivity of different tissues and organs. While the unit of effective dose, like equivalent dose, is the sievert (Sv), it is a very different radiation quantity and should not be confused with it. Effective dose is calculated by multiplying the equivalent dose to a particular tissue/ organ b ...
... radiosensitivity of different tissues and organs. While the unit of effective dose, like equivalent dose, is the sievert (Sv), it is a very different radiation quantity and should not be confused with it. Effective dose is calculated by multiplying the equivalent dose to a particular tissue/ organ b ...
Managing Patient Dose in Multi-Detector Computed Tomography
... There are a number of new influencing parameters specific to MDCT which systematically increase or decrease patient dose compared to single-detector row CT scanners (SDCT). As in earlier developments in CT, there is potential for dose reduction, but the actual dose reduction depends upon how the sys ...
... There are a number of new influencing parameters specific to MDCT which systematically increase or decrease patient dose compared to single-detector row CT scanners (SDCT). As in earlier developments in CT, there is potential for dose reduction, but the actual dose reduction depends upon how the sys ...
chapter 7. clinical treatment planning in external photon
... Simple algorithms, such as Clarkson integration, may be used to determine the dosimetric effects of having blocks in the fields, and calculate dose to off-axis points if their coordinates and source to surface distance is measured. Since only point doses are calculated, the patient shape or contour ...
... Simple algorithms, such as Clarkson integration, may be used to determine the dosimetric effects of having blocks in the fields, and calculate dose to off-axis points if their coordinates and source to surface distance is measured. Since only point doses are calculated, the patient shape or contour ...
Calculation, verification and monitoring of patient dose in Diagnostic
... appearing to have improved (25.1Gy.cm2 for the old lab and 32.2Gy.cm2 for the new lab). The main reason for this increase was due to dose saving filters not being automatically inserted by the system during acquisition runs in the new lab. Medical Physics are working with applications specialists an ...
... appearing to have improved (25.1Gy.cm2 for the old lab and 32.2Gy.cm2 for the new lab). The main reason for this increase was due to dose saving filters not being automatically inserted by the system during acquisition runs in the new lab. Medical Physics are working with applications specialists an ...
Grosche_ANSES-CSO 7
... In general the facts about radon have to be continuously communicated and efforts have to be made to put radon in the “right place”, as e.g. radon is seen as a “rural” problem. The public may know about the severe health effects from radon, but this risk in comparison with other risks is underestima ...
... In general the facts about radon have to be continuously communicated and efforts have to be made to put radon in the “right place”, as e.g. radon is seen as a “rural” problem. The public may know about the severe health effects from radon, but this risk in comparison with other risks is underestima ...
Imaging dose from cone beam computed tomography in radiation
... metaleoxideesemiconductor field-effect transistor (MOSFET), radiographic and radiochromic film, optically stimulated luminescence dosimeter (OSLD), and glass dosimeter have been used for this purpose, many of which produce challenges as to the detector calibration and response to low energy radiation ...
... metaleoxideesemiconductor field-effect transistor (MOSFET), radiographic and radiochromic film, optically stimulated luminescence dosimeter (OSLD), and glass dosimeter have been used for this purpose, many of which produce challenges as to the detector calibration and response to low energy radiation ...
ICRP Publication 105
... The current wR for tritium IS sufficient. It is implicit in the above that calculation and application of protection quantities and radiation and tissue weighting factors need careful thought in the medical context. They are, of course, fundamental considerations in all exposure situations, and someti ...
... The current wR for tritium IS sufficient. It is implicit in the above that calculation and application of protection quantities and radiation and tissue weighting factors need careful thought in the medical context. They are, of course, fundamental considerations in all exposure situations, and someti ...
Estimativa de dose nos pulmões para procedimentos
... Figure 12 – X-ray beam trajectories around the patient for different pitch values. p < 1 results in overscanning (top); for pitch p = 1 there is no overlap of the radiation beam path, and no uncovered regions; for pitch p > 1 some regions may be uncovered due to underscanning. (source: Hypermedia MS ...
... Figure 12 – X-ray beam trajectories around the patient for different pitch values. p < 1 results in overscanning (top); for pitch p = 1 there is no overlap of the radiation beam path, and no uncovered regions; for pitch p > 1 some regions may be uncovered due to underscanning. (source: Hypermedia MS ...
Evaluation and Validation of Computed Tomography Dose Accuracy
... from the two techniques. Tube currents of 140 mAs, 240 mAs and 300 mAs yielded 3.5%, 0.61% and -6.45% deviations when the respective CTDIvol values for both techniques were compared. There were mean CTDIvol of (42.3 + 8.6) mGy and (42.1 + 8.1) mGy for Barracuda and Ion Chamber techniques respectivel ...
... from the two techniques. Tube currents of 140 mAs, 240 mAs and 300 mAs yielded 3.5%, 0.61% and -6.45% deviations when the respective CTDIvol values for both techniques were compared. There were mean CTDIvol of (42.3 + 8.6) mGy and (42.1 + 8.1) mGy for Barracuda and Ion Chamber techniques respectivel ...
Garba_Idris_MASTERS
... manufacturers showed statistically significant differences (p=0.003) and (p=0.03) respectively. In the case of the scanners of a different model but the same number of slices, the comparison of DLP was statistically significant (p=0.005) while no significant difference was noted in the measured CTDI ...
... manufacturers showed statistically significant differences (p=0.003) and (p=0.03) respectively. In the case of the scanners of a different model but the same number of slices, the comparison of DLP was statistically significant (p=0.005) while no significant difference was noted in the measured CTDI ...
A Study on Evaluation of kV-CBCT-image-based Treatment
... inhomogeneous media of the phantom was analyzed to quantify the differences in the image quality of CT and CBCT. To assess the effect of radial scatter, three homogeneous phantoms with radial diameters of 10, 20, and 27 cm, respectively, were scanned using CBCT. 2.3 CBCT-image-based planning 2.3.1 I ...
... inhomogeneous media of the phantom was analyzed to quantify the differences in the image quality of CT and CBCT. To assess the effect of radial scatter, three homogeneous phantoms with radial diameters of 10, 20, and 27 cm, respectively, were scanned using CBCT. 2.3 CBCT-image-based planning 2.3.1 I ...
SBRT: AAPM Task Group 101 Report
... tolerances in the context of SBRT are still evolving. So…. CAUTION! • If part of an IRB-approved phase 1 protocol, proceed carefully • Otherwise, the evolving peer-reviewed literature must be respected! ...
... tolerances in the context of SBRT are still evolving. So…. CAUTION! • If part of an IRB-approved phase 1 protocol, proceed carefully • Otherwise, the evolving peer-reviewed literature must be respected! ...
INTRODUCTION TO TOXICOLOGY
... and quantitation of hazard -develops standards and regulations to protect health and the environment - involved in safety assessment and use of data as basis for regulatory control of hazards - determines risk associated with use of chemicals ...
... and quantitation of hazard -develops standards and regulations to protect health and the environment - involved in safety assessment and use of data as basis for regulatory control of hazards - determines risk associated with use of chemicals ...
Chapter 15 SPECIAL PROCEDURES AND TECHNIQUES IN
... The measured uncertainty in radiosurgical dose delivery for a linac in an excellent mechanical condition is of the order of ±0.5 mm, while for a gamma unit it is somewhat smaller, at ±0.3 mm. Both the gamma unit and the linac provide very similar overall accuracies in dose delivery; however, achievi ...
... The measured uncertainty in radiosurgical dose delivery for a linac in an excellent mechanical condition is of the order of ±0.5 mm, while for a gamma unit it is somewhat smaller, at ±0.3 mm. Both the gamma unit and the linac provide very similar overall accuracies in dose delivery; however, achievi ...
PRINCIPLES OF RADIATION DETECTION AND QUANTIFICATION
... 20% of the public's exposure every year as global average. In the USA by 2006 it averaged about half of the total. This radiation is no different from natural radiation except that it can be controlled. X-rays and other medical procedures account for most exposure from this quarter. Less than 1% of ...
... 20% of the public's exposure every year as global average. In the USA by 2006 it averaged about half of the total. This radiation is no different from natural radiation except that it can be controlled. X-rays and other medical procedures account for most exposure from this quarter. Less than 1% of ...