Board Prep- Rad Safety Flashcards
Radiation Safety
What reduces patient dose, improves image quality, & reduces scatter production?
Beam Restriction
The NCRP regulations state manual collimators must be w/in __% of the SID.
2
The purpose of ___ is to reduce patient skin dose.
Filtration
The NCRP regulations state equipment operating above 70 kV must have total minimum of __ mm/Al equivalent.
2.5
A grid w/ a ratio of __ is recommended for exams using more than 100 kV.
16:1
What principle is demonstrated: when testing mA stations & keeping constant exposure time, twice the mAs should produce twice the exposure.
Linearity
What is the annual occupational exposure dose-equivalent limit?
50 mSv
Undertable bucky slot covers in fluoroscopic rooms require at least the equivalent of __ available.
0.25mm/pb
What type of radiation barrier are the lead walls and doors in an imaging room?
Primary radiation barrier
The leaded glass shield in the control booth should contain __ equivalent.
1.5mm pb
What are the cardinal principles of radiation protection?
Time, Distance, and Shielding
The NCRP regulations state SSD should not be less than __ for all procedures other than dental radiography.
12 inches
The equivalent of traditional unit rem is the ___ in the SI.
Sievert
A TLD can measure radiation doses as low as __ mrem.
5
1 Gy equals __ rad.
100
The annual dose limit of the general population is __ mSv per year.
5
The cumulative exposure for an occupationally exposed individual who is 40 years old must not exceed __ mSv.
400
For pregnant radiographers, the gestational dose limit to the fetus during the gestational period must not exceed __ mSv.
5
What interaction with matter contributes to quantum mottle in an x-ray image?
Compton Scatter
An atom containing 6 protons and 6 neutrons in it’s nucleus has an atomic number of what?
6
Secondary radiation barriers must contain a minimum thickness of __ pb equivalent.
1/32 inches
If linear energy transfer (LET) increases, what effect occurs on relative biologic effectiveness (RBE)?
It also increases (direct relationship)
If a male patient experiences sterility after excessive radiation exposure to the gonads, they are experiencing what type of radiation effect?
Local somatic
Of the following, which is NOT considered a short-term somatic effect: epilation, erythema, cataracts, & epistaxis.
Cataracts
When a minimum amt of radiation is required to produce a predetermined response, the dose response relationship is what?
threshold
What is the maximum exposure rate per minute at the surface of the table top for a conventional fluoroscopic unit?
10 c/kg
What is the term used for radiation effects that are limited to the exposed population only?
Somatic effects
What is the active component of a thermoluminescent radiation monitoring device?
lithium fluoride
During which trimester is the developing fetus considered to be at it’s greatest period of radioresistance?
The third trimester
What is the prescribed distance used when measuring leakage radiation for the housing of a diagnostic x-ray tube?
1 meter
