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Flashcards in Radiation Deck (23):
1

What 3 types of rays are ionizing radiation?

1-UV
2-X-Rays
3-Gamma rays

2

Radiation with sufficient energy to displace atomic electrons is called what?

Ionizing Radiation

3

What is the most significant source of Natural radiation?

Radon (37%)

4

What is the most significant source of Man made radiation?

CT scan (24%)

5

What are the two types of ionizing radiation?

1-Particulate radiation (a and b particles, neutrons)
2-Electromagnetic radiation/photons (gamma and x rays)

6

Radiation exposure is measured in what? SI unit then Traditional unit

Coulomb/kilogram (C/kg), Roentgen (R)

7

Radiation absorbed dose is measured in what? SI unit then Traditional unit

Gray (Gy), rad

8

Radiation equivalent dose is measured in what? SI unit then Traditional unit

Sievert (Sv), rem

9

Radiation effective dose is measured in what? SI unit then Traditional unit

Seivert (Sc), (no traditional unit)

10

Radioactivity is measured in what? SI unit then Traditional unit

Becquerel (Bq), Curie (Ci)

11

Measuring how much air is ionized within a certain volume by a radioactive source is is called air karma and is useful for what?

Measuring exposure

12

Linear Energy Transfer (LET) is like what childhood game?

Marbles (a larger or faster object will transfer more energy to smaller objects)

13

What kind of cells are more affected by radiation as measured by effective dose?

replicating cells

14

When a photon or secondary electron ionizes a biologic macromolecule it is called what?

Direct Effect (1/3 of the biologic damage from x-rays)

15

Free radicals and toxins produced through the intermediate step of water radiolysis which then interact with biologic macromolecules is called what?

Indirect effect (2/3 of the biologic damage from x-rays)

16

What is the primary cause of radiation induced cell death?

Damage to the DNA

17

Radiation injury dependent on dose with an exposure threshold is called what?

Deterministic Effect (generally tissue related)

18

What is primarily effected short term by the deterministic effect?

rapidly dividing cells and undifferentiated stem cells

19

What are the long term effects of irradiation in the deterministic effect?

-loss of parenchymal cells and replacement by fibrous CT
-Loss of capillaries impairing oxygen transport, nutrient transfer and waste removal

20

What are 4 modifying factors of the deterministic effect?

1-Dose
2-Dose rate
3-Oxygen
4-LET

21

Radiation injury based on probability of occurrence is called what?

Stochastic effect (No threshold, no level with zero risk)

22

What are the 2 guiding principles of Radiation safety?

1-justification
2-ALARA (as low as reasonably achievable)

23

How far away should you stand from the radiation source when taking a radiograph?

at least 2 meters (at 90-135 degrees)