Key Terms
An upper boundary limit for radiation workers for yearly whole-body exposure (excluding personal medical and natural background exposure) of 50 mSv. There is also an added recommendation that the lifetime EfD in mSv should not exceed 10 times the occupationally exposed person's age in years.
What is the annual occupational effective dose limit?
The length of time a fluoroscopy unit can be operated continually before an alarm sounds to inform the operator of beam-on time.
What is 5 minutes?
Government agency who regulates the design and manufacturing electronic products, including x-ray machines.
What is the FDA?
This is the first step in protection of the reproductive organ during a radiologic exam.
What is adequate and precise collimation of the x-ray beam?
This is what happens to the enclosed phosphor of a CR cassette when it is exposed to ionizing radiation.
What is engergized?
A value that denotes the percentage of the summed stochastic (cancer plus genetic) risk stemming from irradiation of tissue to the all inclusive risk when the entire body is irradiated in a uniform fashion,
What are tissue weighting factor?
The NID (negligible individual dose) is _____ per source or practice.
What is 0.01mSv/year?
The regulatory standard of total filtration for a fixed x-ray unit operating above 70 kVp.
What is 2.5mm aluminum equivalent?
Abdominal radiologic examinations of the abdomen, after full consideration including pregnancy, do not need to postponed or selectively schedule, when medically necessary, according to this organization.
What is the ACR?
This is the person responsible for maintaining radiation monitoring records for all personnel.
Who is the RSO (radiation safety officer)?
A non-governmental, nonprofit, private corporation that reviews the recommendations formulated by the International Commission on Radiologic Protection (ICRP). The NRCP determines the way ICRP recommendations are incorporated into US radiation protection criteria; recommendations are published in the form of various reports.
What is the National Council on Radiation Protection and Measurements (NCRP)?
The radiation dose that when exceed makes late tissue reactions, such as cataract formation more probable.
What is 2Gy?
This is the effect of radiographic beam filtration in dose to patient's skin and superficial tissues.
What is to reduce exposure?
The anatomical structures that should always be shielded from the useful beam when possible.
What are the lens of the eyes, breasts, thyroid gland and reproductive organs?
Because of the technology, grids are less necessary for pediatric population.
What is computed radiography?
A technique in which the fluoroscopic image exists in digital form at some point in the image acquisition process. In nondigital fluoroscopy, an image intensifier and an analog television camera is used. Typical approaches to digital fluoroscopy include replacement of the image intensifier with a digital detector, replacement of the analog television camera with a digital video camera, and digitization of the analog signal from the analog television camera.
What is digital fluoroscopy?
For students under the age of 18, exposure educational purposes should not exceed this effective dose limit.
What is 1mSv annually?
This the common material used in the radiographic tables to make the tabletop as radiolucent as possible.
What is carbon fiber material?
The minimal source-skin distance that a radiographer must used to minimize radiation exposure to the patient when performing a mobile x-ray.
What is 30cm?
Considering that any organ in the human body is vulnerable to ionizing radiation, it is the underlying motivation for this concept.
What is radiation protection?
Radiation that emerges directly from the x-ray tube collimator and moves without deflection toward a wall, door, viewing window and so on, Also called direct radiation or the useful beam.
What is the useful or primary beam?
The frequency that medical imagining personnel the full annual occupational dose limit.
What is rarely?
The lead-lined metal housing enclosing the x-ray tube that protects both the radiographer and the patient from leakage radiation by restricting the emission of the x-rays to the area of the useful or primary beam.
What is the diagnostic-type protective tube housing?
The person or persons responsible for calculating fetal dose if a pregnant patient is inadvertently irradiated.
Who is the RSO or medical physicist?
The ICRP, NCRP and UNSCEAR are all...
What are radiation protection standards organizations?
All the radiation that arises from the interaction of an x-ray beam with the atoms of a patient or any other object in the path of the beam.
What is scatter radiation?
These analysis provides valuable information for process improvement, helps minimize patient exposure and identifies quality control issues.
What is a department's repeat analysis?
This needs to be increased to compensate for the use of a grid due to some fraction of the image receptor covered with lead.
What is MAS?
This is the approximate GSD for the US population, according to the U.S. Public Health Service.
What is 0.20 mSv?
The term that relates to a random effect of ionizing radiation.
What is stochastic event?
The thickness of a designated absorber (customarily a metal such as aluminum) required to decrease the intensity of the primary beam by 50% of its initial value.
What is the HVL (half-value layers)?
This population is included in the cumulative effective dose (CumEfD).
Who are radiologic technologists?
A device that limits the parameters of the useful beam to a designated size and shape before it enters the area of clinical interest.
What is a x-ray beam limitation device?
The dose range generally used in fluoroscopic image intensification system in an exam on adult patients.
What is 75kVp to 110kVp?
This is the brightness of a surface.
What is luminance?
Any radiographic images that must be performed more than once because of a human or mechanical error during the production of the initial image.
What is a repeat image?
This dose system is superseded by the effective dose (EfD) limiting system.
What is the maximum permissible dose (MPD)?
Reducing field size not only reduces patient dose but also increases recorded image quality by ...
What is decreasing scatter?
A technique chart should be used when manual techniques are need in order to reduce..
What are poor quality image and additional and unnecessary exposure to the patient?
In digital radiography, this is the different shades of gray that can be stored in memory and displayed on a computer monitor.
What is grayscale?
X-ray exposure to the skin of the patient,
What is Entrance Skin Exposure (ESE)?
The NCRP recommends a lifetime occupational dose not to exceed 10 times this amount.
What is the person's age?
Glass envelope encasing the x-ray tube, insulating oil surrounding the tube and glass tube housing are all considered this.
What is inherent filtration?
The combination of these technical exposure factors lower a patient dose.
What is higher kVp, lower mAs?
Effect that is a beneficial consequence of radiation for populations continuously exposed to moderately higher levels of radiation.
What is radiation hormesis?
Concept used to assess the impact of gonadal dose. GSD is the equivalent dose to the reproductive organs that, if received by every human, would be expected to bring about an identical gross genetic injury to the total population, as does the sum of the actual doses received by exposed individual members of the population, this dose is estimated to be about 0.20 mSv.
What is genetically significant dose (GSD)?
This is the estimated whole body equivalent dose the 2000 pregnant women within the 18 mile radial zone of Chernobyl received.
What is 0.43Sv?
This type of fluoroscopy is where manual activation of the fluoroscopic tube by the fluoroscopist or automatic periodic activation (also known as pulsed fluoroscopy) rather than lengthy or continuous activation is used.
What is intermittent fluoroscopy?
In fluoroscopic exams, using last image hold features can have this effect on patient dose.
What is decrease?
Consistency in output in radiation intensity for identical generator settings from one individual exposure to subsequent exposures.
What is exposure reproducibility?