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List particulate radiation
- Beta
- Electrons
- Alpha
- Neutrons
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What % of medical radiation is responsible for radiation exposure today?
Roughly about 50%
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The amount of energy absorbed becomes the absorbed dose which is measured in what?
Rads or Grays
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What is this called when the beam interacts with tissue?
Attenuation
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Attenuation can occur thru what types of effects?
- Absorption (photoelectric effect)
- Scatter (compton effect)
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Does absorption (photoelectric effect) occur in the outer shell or inner shell electron?
Inner shell electron
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Does scatter (compton effect) occur in the outer shell or inner shell electron?
Outer shell electron
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Radiation produced in the tube and traveling is called the...
Primary beam
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The higher the kVp, the _____ absorption to occur. less or more?
Less
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The higher the kVP, the ____ scatter to occur. less or more?
More
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What are the three basic components of reducing radiation exposure?
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When should the radiologic technologist be exposed?
During fluoroscopy exams
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For the inverse square law, as the distance doubles, what happens to the exposure factor?
It decreases by a factor of 4
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What is skin erythema dose and how many rads does it take to get skin erythema?
- How much exposure it takes before the skin turns red
- 300-600 rads
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What is Roentgen?
- Unit of exposure in air
- How much air is being ionized
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What is REM?
- radiation equivalent man
- any exposure that produces the same biologic effect as 1 rad of x-radiation
- occupational exposure
- weighting factors
- equals sieverts
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What is Rad?
- absorbed dose
- what the patient gets
- depends of types or tissues
- equals grays
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X-rays are a __ LET form of radiation. (low or high)
low
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List these from lowest quality factor to highest quality factor (the higher, the more dangerous). x-ray photons (beta particles and gamma photons), thermal neutrons, fast neutrons, alpha particles
- x-ray photons (beta particles and gamma photons)-1
- thermal neutrons-5
- fast neutrons-20
- alpha particles-20
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Radiation weighting factors are based on?
- RBE-relative biologic effectiveness
- They take into account specific cells and tissues
- For diagnostic radiography weighting factors are used
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What takes into account that different types of radiation are more dangerous than others and applies a radiation weighting factor to them? Equivalent dose or effective does?
equivalent dose
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What takes into account that different types of tissues are more sensitive than others and can potentionally cause more damage when irradiated? Equivalent dose or effective does?
effective dose
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Low energy LET cause most damage thru _____ (indirect or direct) effect and is therefore _______ (repairable or irrepairable)?
indirect; repairable
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High energy LET are ____ (more or less) destructive that low LET radiation?
more
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Low LET x-rays have a ____ (low or hight) probability of interacting with DNA?
low
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OER is less with ___ (low or high) LET radiation?
high
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OER is higher with ___ (low or high) LET radiation?
low
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When the x-ray photon strikes the DNA molecule directly, is this a direct or indirect effect?
direct
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When the photon strikes a water molecule and creates an ion pair, this is called?
Radiolysis of water
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List 2 types of free radicals that result from radiolysis of water
- hydrogen peroxide
- hydroperoxyl radical
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When the x-ray photon strikes a water molecule which then produces a free radical which then strikes the DNA this is called? (direct or indirect?)
indirect
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Point mutation commonly occurs with ___ (low or high) LET
low
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What is the main factor for the target theory?
- DNA is the target.
- the DNA molecule is hit and inactivates the cell which then will most likely die
- If you hit the DNA, something is going to happen
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When cells die without attempting cell division is called?
Apoptosis
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When cell death occurs after cell division, this is called?
Mitotic death
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When mitosis occurs after missing a division cycle, this is called?
Mitotic delay
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What is the lethal doese for humans?
300-400 rads; 3-4 grays
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The lethal dose is expressed as LD _/_? What does the first number represent and what does the second number represent?
- 50/60
- The first number is percentage of effect (death in people)
- The second number is how many days for the effect to occur
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Radiation protection uses a linear _______ curve. Non-threshold or threshold?
- Non-threshold
- Any radiation has the potential for problems
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Non-stochastic effects are based on a ______ curve. non-threshold or threshold? They are also called? Deterministic or probabilistic?
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Nausea, fatigue, erythemia, and epilation are types of early non-stochastic, late non-stochastic, early stochastic, or late stochastic? What are these symptoms classified as?
- Early non-stochastic
- ARS-acute radiation syndromes
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What are the three stages of ARS?
- Prodromal (flu-like symtoms)
- Latent (symptoms will resolve or be dormant)
- Manifest (present with many symptoms. You got problems)
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What are three types of ARS?
- Hematopoietic-100-1000 rads
- GI-600-1000 rads
- Cerebrovascular-Up to 5000 rads. Death in 2-3 days
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Cataracts, fibrosis, organ atrophy, and decreased fertility are types of early non-stochastic, late non-stochastic, early stochastic, or late stochastic?
Late non-stochastic
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Cancer and genetic defects are types of early non-stochastic, late non-stochastic, early stochastic, or late stochastic?
late stochastic
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Stochastic effects are based on a ______ curve. Non-threshold or threshold? They are also called? Deterministic or probabilistic?
- Non-threshold
- Probabilistic
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Radiation within 10 days of pregnancy will result in?
A miscarriage.
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The embryo is most sensitive during organogenesis which is from _ weeks to _ weeks. This will result in an embryologic effect.
2 weeks to 8 weeks
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The occupational MPD is __ mSv, __ rem, __ mrem annually.
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The pregnancy MPD is __ mSv, __rem, __ mrem monthly.
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The pregnancy MPD for the entire pregnancy is __ mSv, __ rem, __ mrem.
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The public MPD is __ mSv, __rem, __ mrem.
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The educational MPD is __ mSv, __rem, __ mrem.
- 1 mSv
- 0.1 rem
- 100 mrem
- Same as the public MPD
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Radiation hormesis is?
The potential that small radiation exposure is actually beneficial
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Collimator and light field is +/- __% of the SID
2%
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