Radiation Protection

Question 1

What is the primary purpose of filtration?

Answer 1

To reduce ESE to the patient

Question 2

What is the total filtration needed for the following:

Below 50 kVp
50-70 kVp
Above 70 kVp

Answer 2

.5 mm aluminium
1.5 mm aluminum
2.5 mm aluminum

Question 3

What is the best way to reduce involuntary motion

Answer 3

Short exposure time

Question 4

What exposure factors are used for fluoroscopy?

Answer 4

Increased kVp, low mA

Question 5

In fluoro, is entrance exposure or exit exposure greater?

Answer 5

Entrance

Question 6

What is the minimum source to skin distance in fluoroscopy?

Answer 6

Fixed unit = 15” (38cm)
Mobile = 12” (30cm)

Question 7

What is the greatest source of natural radiation?

Answer 7

Radon

Question 8

What is the gretest source of artificial radiation?

Answer 8

Medical imaging

Question 9

What is the minimum lead requirement for lead aprons?

Answer 9

.5 mm

Question 10

What is the minimum lead requirement for gloves?

Answer 10

.25 mm

Question 11

What is the minimum lead requirement for a thyroid shield?

Answer 11

.5

Question 12

What is the minimum lead requirement for glasses?

Answer 12

.35

Question 13

What is the minimum lead requirement for the bucky slot cover?

Answer 13

.25

Question 14

What is the minimum lead requirement for spot film device protective curtain?

Answer 14

.25

Question 15

What is the minimum lead requirement for clear lead-plastic overhead protective barrier?

Answer 15

.5

Question 16

Where are primary protective barriers needed?

Answer 16

On surfaces that can be struck by the primary beam; barriers located perpendicular to the primary beam

Question 17

What is the lead requirement in a primary protective barrier?

Answer 17

1/16” (.16cm or 1.6mm)

Question 18

If the primary barrier is a wall, the lead must extend how far up from the floor?

Answer 18

7 ft (2m)

Question 19

Is the control booth a primary or secondary barrier?

Answer 19

Secondary

Question 20

Where are secondary protective barriers needed?

Answer 20

Surfaces that are struck with leakage and scatter radiation; barriers located parallel to the primary beam

Question 21

What is the lead requirement in a secondary protective barrier?

Answer 21

1/32” (.08 cm or .8mm)

Question 22

How much of the secondary barrier must overlap the primary barrier where the two meet?

Answer 22

1/2”

Question 23

Type of dosimeter that relies on the ability of ionizing radiation to effect a density change on the film emulsion

Answer 23

Film badge

Question 24

What type of attenuating filters are used in film badges?

Answer 24

Tin or copper

Question 25

What are the benefits of film badges?

Answer 25

Effective for radiation over extended periods of time Inexpenisve Provide a permanent record

Question 26

What is the functional component of a TLD?

Answer 26

Lithium fluoride

Question 27

How is a TLD read?

Answer 27

Heating the lithium fluoride chip to the point of combustion; the light spectrum will change with changing levels of energy absorbed in the chip

Question 28

Disadvantages of TLD?

Answer 28

More expensive than film badges Once the chip is heated, it is destroyed; no permanent record

Question 29

What type of dosimeter relies on the ability of the ionizing radiation to ionize a gas within a sealed chamber resulting in a change of a charged electrode

Answer 29

Pocket dosimeter

Question 30

What is a pocket dosimeter good for?

Answer 30

Short-term monitoring or testing

Question 31

What type of dosimeter gives an immediate reading?

Answer 31

Pocket dosimeter

Question 32

Disadvantage of pocket dosimeter?

Answer 32

Prone to inaccurate readings; no permanent record

Question 33

What is the benefit of pocket dosimeters?

Answer 33

Unit may be recharged and reused

Question 34

What type of detector is in an OSLD?

Answer 34

Aluminum oxide

Question 35

How is an OSLD read?

Answer 35

Laser light reads the sensing material which causes the material to become luminescent in proportion to the exposure

Question 36

What type of filters are within an OSLD?

Answer 36

Aluminum, tin and copper

Question 37

Rank the following dosimeters from most sensitive to least: TLD OSL Pocket Film badge

Answer 37

Pocket OSL TLD Film badge

Question 38

What is the annual whole body dose limit for occupational exposure?

Answer 38

50 mSv

Question 39

What is the occupation exposure limit for lens of the eyes?

Answer 39

150 mSv

Question 40

What is the cumulative effective limit?

Answer 40

10 mSv x age in years

Question 41

What is the annual effective dose equivalent limit for public exposure?

Answer 41

5 mSv

Question 42

What are the dose equivalent limits for the lens of the eyes, skin and extremities for public exposure?

Answer 42

50 mSv