RAD BIO Test 1 review Flashcards
What type are the radiation measurement units for radiation biology?
What are these units?
Systeme international SI
Grays, sieverts, and coulombs*
What is exposure?
What units do we use to measure this?
Amount of radiation in the primary beam (x-ray tube output/air) (what’s in the air?)
Coulombs per kilogram (C/kg)
What is absorbed dose?
What is the unit of measurement for this?
Which also equals?
Energy per unit mass absorbed by an irradiated object
(What’s the radiation striking patient/healthcare worker)
Gray (Gy)
1 J/kg = 1 Gray
What is dose equivalent?
What is the unit we use for measurement?
Absorbed dose x radiation weighting factor
(What type of radiation is hitting us)
Sievert (SV)
What are the radiation weighting factors?
What are there values?
Gamma ray = 1
x-ray= 1
positron= 1
proton= 2
alpha particles= 20
What is effective dose?
What is the main thing that it accounts for?
what is the formula for this?
What is the unit for measuring this?
The sum of the equivalent doses for all irradiated tissues
Considers the type of radiation and the sensitivity of the tissues
Absorbed dose x radiation weighting factor x tissue weighting factor
Sieverts
What are these tissue weighting factor for these?
Gonads:
Red bone marrow:
Colon:
Liver (organs):
Skin:
0.20
0.12
0.12
0.05
0.01
What is Air KERMA?
What does this stand for?
What is the unit of measurement for this?
Kinetic energy of the air in the primary beam
Kinetic energy released in matter
Gray (Gy)
What is the dose area product?
How can this be measured?
Takes into account the area being irradiated
DAP meter
(More area radiated, more radiation)
(Increased collimation= less DAP)
(Decreased collimation = more DAP)
What is half-life?
Specific to:
Time required for radioactivity to reduce to half its original measurement
Isotope and constant
If we have 12 mGy with a 6 hour half life, how much time will it take for the radiation to get to 6 mGy?
For 3 mGy?
6 hours
12 hours
For radiation with 24 mGy how much time will need to pass for us to reach 3 mGy with a 6 hour half life?
18 hours
What is the integral dose?
What is an example of this?
sum of a all absorbed doses in an exam
L-spine (AP + LAT + OBL)
What is the annual limit for natural radiation? Where does this radiation originate from?
What is the limit for manmade?
3 mSv & radon gas which is highest in tightly sealed structures such as granite/marble
3 mSv
What is an OSL or OSLD?
How is it released?
Optically stimulated luminescent dose (dosimeter)
released by light
What is a TLD?
How is it released?
Thermoluminescent dose (dosimeter)
By heat
What is a film badge?
What is the purpose of this?
A dosimeter with a small piece of film/ foil filter
For determining the type of radiation
(Ex: alpha particles)
What is a pocket or ion chamber?
What is an example of this?
Real-time dose readings using anode pin or plate
Pen or Geiger counters/ AEC (not for general use)
What is the occupational dose limit?
Where do we see most of this at?
50 mSv
Fluoroscopy
What is the radiation limit for the public?
1 mSv
What is the limit for the fetus?
0.5 mSv/month
what is the dose limit for the lens of the eye?
150 mSv
what is the radiation dose limit for everything else?
500 mSv
what does LET stand for?
what is it?
linear energy transfers
Amount of energy deposited in tissue per radiations travel
(How much energy is given off into the tissue)
What does high LET mean?
What is an example of this?
More concentrated which means more harmful to tissue
(like alpha particles)
What is an example of low LET?
What is an example of high LET?
Gamma ray (lowest) & x-ray (2nd lowest)
Alpha particles
Which has the lowest LET, x-ray or gamma ray?
Gamma ray
What does RBE stand for?
What does it do?
Relative biological effectiveness
Compares different types of radiation
If one type of radiation can cause the same effect as the other with a lower amount (quantity) this type has?
A higher relative biological effectiveness (RBE)
what is radiation response curves?
What are the types of these?
Graph (ic) representation of the biological response to increasing doses of ionizing radiation
Linear or non-linear/ threshold or non threshold-hold
