Unit 4

Question 1

What does ICRP stand for?

Answer 1

International Commission on Radiation Protection

Question 2

What does NCRP stand for?

Answer 2

National Council on Radiation Protection and Measurements

Question 3

What does the NCRP do?

Answer 3

A US group, they write policy for the US

Question 4

What is UNSCEAR?

Answer 4

General assembly of UN created in 1955. Assess & report levels and effects of exposure to ionizing radiation. Governments and organizations worldwide rely on the information for establishing protective measures.

Question 5

NAS/NRC - BEIR

Answer 5

National Academy of Sciences, National Research Council committee on the Biologic Effects of Ionizing Radiation

Question 6

Which organizations are advisory groups?

Answer 6

UNSCEAR and NAS/NRC-BEIR

Question 7

Who does UNSCEAR and NAS/NRC-BEIR report data to?

Answer 7

IRCP

Question 8

Who makes recommendations on occupational and public dose limits? What do they base these recommendations on?

Answer 8

IRCP. They base it on info from UNSCEAR and NAS/NRC-BEIR

Question 9

Who implements the IRCP’s recommendations implements them into US radiation protection policy?

Answer 9

NCRP

Question 10

Who are the US regulatory agencies for radiation protection?

Answer 10

NRC (Nuclear Regulatory Commission), EPA, FDA, OSHA and state agencies.

Question 11

Who oversees the nuclear energy industry and controls the manufacture, use and disposal of radioactive substances used in nuclear reactors?

Answer 11

NRC

Question 12

Who facilitates development & enforcement of regulations pertaining to control of radiation in the environment?

Answer 12

EPA

Question 13

Who monitors places of employment?

Answer 13

OSHA

Question 14

What organization regulates design and manufacturing of electronic products including diagnostic x-ray equipment?

Answer 14

CDRH (Center for Devices of Radiologic Health)

Question 15

What is the important US legislation as far as radiation control?

Answer 15

Radiation Control for Health and Safety Act of 1968. (for consumers) Patient Radiation Health and Safety Act of 1981. CARE bill proposed legislation.

Question 16

Who are two required people or groups in any radiation safety program?

Answer 16

Radiation Safety Committee and Radiation Safety Officer

Question 17

Who is normally the Radiation Safety Officer?

Answer 17

Usually a medical or health physicist, radiologist or other appropriately qualified individual.

Question 18

What are the responsibilities of the Radiation Safety Officer?

Answer 18

Ensures radiation safety program to protect all persons, maintain radiation monitoring records, provides counseling for individuals.

Question 19

What concepts are dose limits based on?

Answer 19

Linear non-threshold, risk vs benefit, ALARA

Question 20

Who recommends dose limits?

Answer 20

NCRP

Question 21

Why is effective dose used instead of equivalent dose?

Answer 21

The equivalent dose only takes into account the type of radiation. Effective dose takes into account the type of radiation & radiosensitivity of irradiated tissue or organs.

Question 22

What is the effective dose limit for the lens of the eye in traditional and SI units?

Answer 22

15 Rem (15,000mRem) and 150 mSv

Question 23

What is the effective dose limit for the skin, feet and hands in traditional and SI units?

Answer 23

50 Rem (50,000 mRem) and 500 mSv

Question 24

What is the whole body effective dose limit in traditional and SI units annually?

Answer 24

5 Rem (5,000 mRem) and 50 mSv

Question 25

What is the whole body effective dose limit in traditional and SI units cumulatively?

Answer 25

1 Rem x age and 10 mSv x age

Question 26

What should happen when a tech chooses to declare her pregnancy?

Answer 26

She should be given a second dosimeter to be worn under her apron at waist level to give fetal dose

Question 27

What is the effective dose limit in traditional and SI units for a pregnant tech for the entire pregnancy?

Answer 27

0.5 Rem (500 mRem) and 5 mSv

Question 28

What is the effective dose limit in traditional and SI units for a pregnant tech for each month of the pregnancy?

Answer 28

0.05 Rem (50 mRem) and 0.5 mSv

Question 29

What are action limits?

Answer 29

A high badge reading the triggers an internal investigation

Question 30

Who sets the notification level for an action limit?

Answer 30

The facility that employs the tech

Question 31

Who is monitored for radiation exposure levels?

Answer 31

Any worker who is regularly exposed and likely to receive over 1/10 of the recommended dose equivalent dose limit

Question 32

What are the four types of dose monitoring devices?

Answer 32

Film badge, OSL, TLD, Pocket Ionization Dosimeter.

Question 33

What does a film badge contain?

Answer 33

Film with filters (aluminum, copper & tin)

Question 34

What is the OSL dosimeter?

Answer 34

Optically stimulated Luminescence Dosimeter.

Question 35

What type of material is the OSL dosimeter and how is it read?

Answer 35

Made of material similar to a CR imaging plate. Scanned by laser beam and amount of emitted light is measured.

Question 36

What is a TLD dosimeter? What form does it usually take?

Answer 36

Thermoluminescent Dosimeter. A ring.

Question 37

Who wears TLDs?

Answer 37

Measures hand exposure of people who handle radioisotopes or people who have their hand in the primary beam.

Question 38

How does TLDs work?

Answer 38

X-rays hit TLD phosphor, energy is stored by the phosphor, subjected to heat to be read, emits light and the amount of light is measured.

Question 39

What measurement does the pocket dosimeter use?

Answer 39

mR

Question 40

What is a pocket dosimeter?

Answer 40

Ionization chamber to measure exposure.

Question 41

What is the function of control monitors?

Answer 41

Measures background exposure. This reading is subtracted from personnel monitors. Should be kept in distant room or office away from radiation areas.

Question 42

Who reviews the radiation monitor reports?

Answer 42

RSO for compliance each month.

Question 43

What are two types of ionization chamber field survey instruments?

Answer 43

Cutie Pie, Geiger-Muller counter

Question 44

What is a GM counter used for?

Answer 44

To detect x-, gamma and beta radiation (not alpha because it doesn't penetrate). Primarily used to locate spills.

Question 45

What does the GM counter measure exposure in?

Answer 45

Roentgens or Coulombs/kg

Question 46

What does the Cutie Pie measure?

Answer 46

Exposure rate and cumulative exposure. Used to test for leakage but also for scatter.

Question 47

What are field survey calibration instruments used for?

Answer 47

Output of radiographic and fluoro equipment, mR/mAs, generator linearity and reproducibility, HVL, timer accuracy, fluoro entrance exposure rates

Question 48

What monitors patient dose?

Answer 48

DAP meter.

Question 49

Where is a DAP meter found?

Answer 49

On new fluoro and angiography equipment.

Question 50

How is DAP calculated?

Answer 50

surface area of patient at skin entrance multiplied by the radiation dose at this surface. cGy x cm^2

Question 51

What are the three cardinal principles of radiation protection?

Answer 51

Time, shielding, distance

Question 52

Where is a primary radiation barrier found?

Answer 52

Perpendicular to undeflected line of travel of the x-ray beam.

Question 53

What is a secondary radiation barrier exposed to?

Answer 53

Scatter and leakage radiation

Question 54

What materials are usually used for primary radiation barriers?

Answer 54

Lead and concrete

Question 55

What materials are usually used for secondary radiation barriers?

Answer 55

Lead, steel, leaded glass, gypsum, thick wood.

Question 56

What are the factors affecting radiation barrier thickness?

Answer 56

Workload, inverse square law, use factor, occupancy factor, controlled vs uncontrolled area, max kVp, primary vs secondary barrier.

Question 57

What is workload?

Answer 57

(W) Weekly radiation-on time

Question 58

What is the formula for workload?

Answer 58

W=# days a week x # pts a day x # exposures per pt x mA x s x 1 minute

Question 59

What is the use factor?

Answer 59

(U) aka Beam Direction Factor. The percentage of beam-on time that the beam is directed at that barrier. Full use U=1, partial use U=1/4 (wall, door), occasional use U=1/16 (ceiling)

Question 60

What is the occupancy factor?

Answer 60

(T) The time that the area adjacent to the exam room is occupied.

Question 61

What are the values for occupancy factor?

Answer 61

T=1 if area is fully occupied (office), 1/2 if pt exam or tx room, 1/5 if corridor or lounge, 1/20 if restroom or storage room, 1/40 if stairway or closet.

Question 62

What is controlled vs uncontrolled ares?

Answer 62

Controlled area is primarily occupied by personnel and pts (100 mRem/week). Uncontrolled area is an area that can be occupied by anyone (2 mRem/week)

Question 63

What should tube leakage be limited to?

Answer 63

Less than or equal to 100 mR/hour at on meter from tube while tube is energized at max technical factors.

Question 64

What is the primary barrier for a fluoro unit?

Answer 64

Image Intensifier

Question 65

What needs to be the thickness of the primary barrier for a fluoro unit?

Answer 65

2 mm Pb eq

Question 66

What is the main secondary barrier for a fluoro unit?

Answer 66

Curtain or sliding panel

Question 67

What is the minimum protection for the main secondary barrier for a fluoro unit?

Answer 67

at least 0.25 mm Pb eq (bucky slot cover also)

Question 68

What is the minimum thickness for lead gloves and aprons?

Answer 68

At least 0.25 mm Pb eq. 0.5 mm Pb eq provides significantly more protection.

Question 69

When and where should a patient be shielded?

Answer 69

Shield sensitive organs (as long as it won't obscure area of interest) if the AOI is within 5 cm of properly collimated beam.