Tsukoyomi

Question 1

SI

Answer 1

International System: ARRT will test using SI system

Question 2

Coulomb/kilogram

Answer 2

Unit that measures amount of gamma or xrays in air

Question 3

Gray

Answer 3

Measures amount of radiation absorbed by matter

Used for patient exposure -J/Kg

Question 4

Air Kerma

Answer 4

Amount of radiation delivered to specific point in air - J/Kg

Question 5

Sievert or rem

Answer 5

Unit for measuring biological damage from radiation

Used for occupational worker exposure

Question 6

Photoelectric Effect

Answer 6

1. xray photon strikes an inner shell electron and is absorbed
2. inner shell electron is knocked out of orbit
3. outer shell electron drops into inner shell vacancy
4. transitioning electrons release energy known as characteristic or secondary radiation
   Greatest hazard to patient due to xray absorption

Question 7

Compton Effect

Answer 7

1. incident xray photon strikes an outershell electron
2. outer shell electron is ejected
3. the photon continues on altered path
   Both scatter photon and recoil electron have reduced energy and travel on to interact with other atoms
   Responsible for the majority of occupational exposure

Question 8

Ionizing Radiation

Answer 8

Possesses sufficient energy to eject orbital electrons, capable of penetrating matter, produces ions

Question 9

X-rays cause damage to living cells. Damage may be:

Answer 9

Repaired by cell itself
permanent
cause cell death

Question 10

Direct Hit Theory

Answer 10

Radiation strikes a DNA molecule

Question 11

Indirect Hit Theory

Answer 11

Radiation hits a water molecule

Question 12

Radiolysis

Answer 12

Ionization of water molecules causing them to split

Causes chemical changes that results in free radicals

Question 13

Free Radicals

Answer 13

Highly reactive particles that can indirectly harm DNA

Cause illness and aging

Question 14

Law of Bergonie & Tribondeau

Answer 14

Undifferentiated cells
Rapidly dividing cells are more sensitive to radiation exposure
Fetus and infants are most susceptible to negative effects of radiation
1st trimester is most sensitive time for fetus

Question 15

Most sensitive cells

Answer 15

Lymphocytes (20-40% of all white blood cells)
Lens of eye, ovaries, testes
Mucosal linings - GI system, nose, mouth
Glandular Tissue - Breast, thyroid

Question 16

Somatic

Answer 16

All cells except germ cells

Question 17

Nonstochastic

Answer 17

A threshold of exposure has been exceeded
Usually short term exposure
Cataracts, erythema

Question 18

Stochastic

Answer 18

No threshold
Increased possibility an effect will occur as a result of any amount of radiation
Long term effects:
-cancer
-Life span shortening
-Birth defects
Mental retardation

Question 19

Genetic

Answer 19

Damage to cells responsible for sexual reproduction

• miscarriages
• Birth defects
• Sterility

Question 20

RT’s and student’s responsibility:

Answer 20

Protect patient, staff, and self

Question 21

Linear

Answer 21

No threshold

No amount of radiation has been proven safe

Question 22

ALARA

Answer 22

As low as reasonably achievable

Question 23

3 Cardinal Rules

Answer 23

Time
Distance
Shielding

Question 24

Dose Limits

Answer 24

Occupational
Whole body = 50mSV
Life time = 10msv x age
Student = 1 msv
Pregnant = 5 msv during pregnancy
Public
WHole body = 5msv
Pregnant=5msv during prenancy

Question 25

Affects on fetus

Answer 25

Spontaneous abortion Congenital defects Genetic abnormalities Neonatal death

Question 26

Pregnant radiographer:

Answer 26

Fetal badge worn at waist

Question 27

Reducing radiation dose

Answer 27

``` Exposure Distance Collimation Filtration Reduce repeats gonadal shielding ```

Question 28

kVp

Answer 28

penetration & beam quality Lower kVp = less penetrating - used for smaller and thinner objects Higher kVp = more penetrating - used for larger thicker parts Higher kVp reduces patient dose Too high leads to excessive scatter and brightness of image (too dark) Too low leads to under exposure

Question 29

mA

Answer 29

Milliamperage | Controls amount of current going through filament

Question 30

S

Answer 30

Seconds Controls length of exposure Influences the quantity

Question 31

Distance

Answer 31

40" for most table top and table bucky work, used mostly with upright bucky, and portable xrays 72" for upright bucky, may be used with portable machine

Question 32

Collimation

Answer 32

Limits field size Reduces patient exposure Reduces scatter

Question 33

Repeats

Answer 33

Leads to double exposure. Use postioning devices, clear communication, know anatomy

Question 34

AEC

Answer 34

Automatic exposure control A device that helps terminate exposure when preset amount of radiation has been detected Only controls exposure time Available when there are ionization chambers Located between patient and IR

Question 35

When is gonadal shielding required?

Answer 35

If gonads are within 5cm of primary beam

Question 36

Gonadal shielding

Answer 36

Shadow Shaped contact Flat contact