Radiation Protection Ch 13 Part 1 and 2 Flashcards
designed to limit exposure to reasonable levels of risk comparable with risk from other common sources
dose limit
expresses the relationship between distance and intensity (quantity) of radiation and governs the dose received
inverse square law
prevents direct or unscattered radiation from reaching from reaching personnel or members of the general public on the other side of the barrier
primary protective barrier
typical installation of primary protective barrier
consist if 1/16” (1.6mm)lead that extends 7ft (2.1m) upward from the floor of the x-ray room when the x-ray tube is 5-7ft from wall in question
where are primary protective barrier located
undeflected line of travel of the x-ray beam
consist of radiation that has been deflected from the primary. Leakage from the tube housing and scatter make it up.
secondary radiation
protects against secondary radiation (leakage and scatter))
secondary protective border
classification of the secondary protective barrier
any wall or barrier that is never struck by the primary beam is classified as a secondary protective border
typical installation of the secondary protective barrier
should overlap the primary protective barrier by 1/2” and consist of 1/32” lead
secondary protective barrier: must extend 7ft upward from the floor and permanently secured to it. X-ray should scatter a minimum of 2 times before reaching any area behind it.
control booth barrier
what is the annual occupational dose?
EfD=50mSv or 5 rem whole body
what the lifetime effective dose recommendations is
should not exceed 10xs the occupationally exposed persons age in years
what is the annual effective dose limit allowed for nonoccupationally exposed individuals frequent exposure?
1 mSv (0.1 rem)
what is the annual effective dose limit allowed for nonoccupationally exposed individuals for infrequent exposure?
5 mSV (0.5 rem)
know the 9 dose-reduction methods and techniques
- Avoiding repeat examinations
- the pt is a source of scattered radiation
- scattered radiation occupational hazard
- filtration of the x-ray beam
- protective apparel
- technical exposure factors
- use of high speed image receptor systems
- retakes in digital imaging
- correct processing of radiographic images
know the process that make the patient become a source of scatter radiation
Compton interaction process
at what angle and distance should a technologist stand, because the intensity of the scatter is approximately 1/1000 of the primary beam?
90 degree angle at a distance of 1m (3.3 ft)
what poses the greatest occupational hazard in radiology
scatter radiation
what s the first step in a pregnancy policy that makes the facility recognize the pregnancy
voluntary declaration of pregnancy
know what the pregnant worker does after receiving radiation safety counseling
must read and sign a form acknowledging they received the counseling and understands the ways to implement appropriate measure to ensure the safety
know what maternity protective apparel must consist of
maternity aprons consist of 0.5 mm lead over their entire length and width and have an extra 1mm lead equivalent protective panel that runs transversely across the width of the apron for added protection
if regular wraparounds are worn by a pregnant worker how much lead equivalency must be in them
0.5 mm lead equivalent
know the 3 basic principles of radiation protection
time, shielding, distance
know what the amount of radiation received is directly proportional to
length of time for which the individual is exposed to radiation
under the cardinal principle of time, when is the only time a radiographer should be present in a fluoroscopic exam
only when needed to perform relevant patient care and to fulfill respective duties associated with the procedure