Unit 3 Flashcards
A term that is synonymous with loss of hair is
Epilation
Some mutations in genetic material occur spontaneously, without a known cause. In humans, a hereditary disorder is present in approximately____ of all live births in the United States.
10%
The light localizer must be within what percentage of the SID?
2%
NOTE:
Tape measure or laser distance must be accurate within 2% of SID.
Centering indicator must be accurate to within 1% of SID.
A variation of 10% or less is considered acceptable when verifying a machine’s ____
Exposure linearity
The regulation responsible for ensuring that each patient should get the right imaging exam, at the right time, and with the right dose is?
The White Paper
Based on recent data, the threshold for single exposures to cause cataract is
0.5 Gy
The use of high-level fluoroscopy for extended periods of time can result in which of the following?
- ARS
- Repair of damaged chromosomes
- Radiation induced skin injuries
3 only
ARS- Acute Radiation Syndrome (Early Somatic Effect- Large whole body exposures)
Early tissue (deterministic) reactions may include:
- Nausea
- Decreased sperm count
- Epilation
- Cancer
1, 2, and 3
Radium watch dial painters ingested large quantities of radium in the 1920s causing
Osteoporosis- disease that causes bone mass decrease
The x-ray tube protective housing is designed to
- Restrict off focus radiation
- Restrict radiation leakage
- Filter out low energy photons
1 and 2 only
Another method health care institutions have established to ensure that personnel dose limits do not approach EfD limits is through the use of
Action limits
NOTE: Once 10% of annual exposure dose limit is exceeded, facility triggers an investigation.
For persons with hematopoietic syndrome, survival time shortens as the radiation dose
Increases
During a fluoroscopic examination, a resettable cumulative timing device measures the x-ray beam-on time and sounds an audible alarm or in some cases temporarily interrupts the exposure after the fluoroscope has been activated for what length of time?
5 minutes
All are considered stochastic effect of radiation EXCEPT.
Nausea
Fluoro Units with High Level Control may have an exposure rate of as high as ____ with 12” above table top
176 mGy
Based on the diagram A above, #3 represents a dose response curve that is referred to as:
Nonlinear threshold
ALARA is referred to as Optimization radiation protection
True
The term used to describe the routine practice of overexposing patient to avoid repeats while using digital imaging is referred to as:
Dosage creep
Based on the diagram A above, #2 is considered
linear threshold
According to the NCRP Report No. 116, which of the following is the monthly equivalent dose limit for pregnant workers?
0.5 mSv
Early tissue reaction may appear within
- Minutes
- Years
- Hours
1 and 3
What are the benefits of using pulsed/intermittent fluoroscopy during a fluoroscopy procedure?
Extends tube life and decreases patient dose
Based on the diagram A above, #3 is representative of:
cataractogenesis
Which radiation protection organization evaluates human and environmental ionizing radiation exposures from a variety of sources and derive risk assessment for radiation induced cancer and genetic effects?
UNSCEAR
Determine the cumulative effective dose (CumED) limit to the whole body of an occupationally exposed person who is 46 years old.
460 mSv
NOTE: Age in years x 10 mSv
Which of the following late effects caused by exposure to ionizing radiation is considered to be most important?
Cancer
The science that deals with the incidence, distribution, and control of disease in a population is referred to as:
Epidemiology
The annual effective dose limit for occupational workers is
5 rem (50 mSv)
The lead organization responsible to provide radiation protection guidance is the
ICRP
What is the mean value of the radiation doubling equivalent dose for humans, as determined from studies of the children of the atomic bomb survivors of Hiroshima and Nagasaki?
1.56 Sv
What is the total filtration necessary for x-ray units operating at 50 kVp-70 kVp?
1.5 mm aluminum
NOTE:
Below 50: 0.5 mm
50-70: 1.5 mm
Above 70: 2.5 mm
Which of the following combinations of technical exposure factors and filtration reduce patient radiation dose during a radiographic exam?
higher kVp, lower mAs, increased filtration
Atrophy refers to
Shrinkage of organs and tissues after a high radiation dose is received
Based on the diagram A above, which dose response curve represents cancer induction and genetic mutation?
1
The enforcing agency that regulate the design and manufacturing of electronic products including radiographic equipment is
FDA
If a person receives radiation exposure sufficient to cause the gastrointestinal syndrome, fatality occurs primarily because of
catastrophic damage to the epithelial cells that line the gastrointestinal track, resulting in the death of the exposed person within 3 to 5 days from a combination of infection, fluid loss, and electrolytic imbalance.
Which of the following is not a form of acute radiation syndrome?
Carcinogenic syndrome
What determines the rate of production of chromosome aberrations?
- The total radiation dose given to a somatic cell
- The total radiation given to a genetic cell
- The period of time in which radiation dose was delivered
1, 2, and 3
Irradiation of gonadal tissue from ionizing radation at any dose may result in:
Genetic effects
The most radiosensitive period during pregnancy is the
First trimester
Occasional exposure for the purpose of education and training is permitted, provided that special care is taken to ensure that the annual effective dose limit of ____ is not exceeded for persons under the age of 18 years.
1 mSv annually
The term LD 50/30 signifies the whole-body dose of radiation that can be lethal to
50% of the exposed population within 30 days.
The risk model that predicts the number of excess cancers will increase as the natural incidence of cancer increases with advancing age in a population is
Relative risk model
NOTE: Absolute risk model- estimates that a specific number of malignancies will occur as a result of exposure
Which regulation establishes the minimum standards for accreditation of education programs for radiographers?
The Consumer Patient Radiation Health and Safety Act of 1981
Leukemia and Genetic mutations are considered random effects
True
A radiation safety officer in a health care facility must have sufficient authority, organizational freedom, and management prerogative to
- identify radiation safety problems.
- initiate, recommend, or provide corrective action.
- stop unsafe operations involving by-product material.
- verify implementation of corrective actions.
1, 2, 3, and 4
The concept that claims there is benefits to small amounts of radiation exposure is referred to as
Radiation hormesis
Which of the following is NOT a x-ray beam limitation device?
Inherent filtration
Radiographic grids should be employed when a body part is
Thicker than 10 cm
Which dose is found to depress the male sperm population?
0.1 Gy
