Module 12 Part 2 Flashcards
(37 cards)
The unit used to quantify amount of radiation exposure
Roentgen (R)- technically only applies to x rays and gamma rays
Unit used to express the absorbed dose/quantity of energy from radiation absorbed per unit mass
Gray (Gy). (Joules per kg)
RAD. Old unit, stands for ….
Radiation absorbed dose
SI unit of equivalent dose for a given tissue = (Gy X radiation weight factor (WR))
Sievert (Sv)
Roentgen equivalent man
(rem) unit dose equivalent in humans
Biological effects of ionizing radiation are ______ to time of exposure
Proportional
Radiation exposure is _____ proportional to the square of the distance from the radiation source
Inversely
Annual occupational effective dose limit per year
5,000 mrem
Cumulative lifetime effective dose limit
1,000 mrem/year times age
Embryo or fetus should not exceed this dose per gestational period
500 mrem
Exceeding the cumulative lifetime effective dose causes increased risk for what?
Cancer
What body parts have lower limits for radiation exposure
Lens of the eye and reproductive organs, embryo or fetus
ALARA stands for…..
As Low As Reasonably Achievable
ALARA standards
Avoid radiation when there is no direct benefit: diagnostic and/or therapeutic
Minimize exposure: use the lowest radiation dose for shortest time to achieve desired result
increased distance from radiation source
maximize use of shielding
Occupational exposure is primarily from this effect of ionizing radiation
Scatter off patients
Which Alara principal is the best protection
Distance
Recommended number of feet a provider should be from the radiation source
6 ft
Alara time concepts
Keep exposure minimum
Exposure is cumulative and permanent
Exposure does decreases as time shortens
These three things increase ionizing radiation scatter
Increase body weight
Increase thickness and density of body part
X-ray tube and lateral position

Ionizing radiation travels in a _______ ______ and is not capable of _______.
Straight line
Bending
_______ should be placed between provider and radiation source
Shielding
Radiation Shielding can be provided by….
Concrete wall her mobile lead shield or lead apron with thyroid shield and eye protection
Lead apron, thyroid shield,
and eye protection reduce occupational exposure by what percent
25%
Where are dosimetry badge is worn
Collar level outside of lead apron
