Radiobiology Unit 4

Front 1

Makes recommendations on occupational and public dose limits based on information from UNSCEAR and NAS/NRC-BEIR.

Back 1

ICRP (International Commission on Radiological Protection

Front 2

Reviews ICRP recommendations and implements them into US radiation protection policy.

Back 2

NCRP (National Council on Radiation Protection and Measurements)

Front 3

It's mandate in the United Nations system is to assess and report levels and effects of exposure to ionizing radiation. The governments and organizations rely on the estimates as the scientific basis for evaluating radiation risk and for establishing protective measures.

Back 3

UNSCEAR

Front 4

NAS/NRC-BEIR What does this stand for?

Back 4

National Academy of Sciences/National Research Council Committee on the Biological Effects of Ionizing Radiation

Front 5

Both are advisory groups that review research and studies on biologic effects of ionizing radiation and risk assessment and supplies information to the ICRP.

Back 5

UNSCEAR

NAS/NRC-BEIR

Front 6

Federal agency whose main function is to oversee the nuclear energy industry that controls manufacture, use and disposal of radioactive substances formed in nuclear reactors.

Back 6

NRC (Nuclear Regulatory Commission)

Front 7

Facilitates the development and enforcement of regulations pertaining to the control of radiation in the environment. E.g. radon

Back 7

EPA (Environmental Protection Agency)

Front 8

Regulates design, manufacture of electronic products including diagnostic x ray equipment

Back 8

FDA and CDRH (Food and Drug Administration) (Center for Devices and Radiological Health)

Front 9

Monitors places of employment. "Right to know"

Back 9

OSHA (Occupational Safety and Health Administration)

Front 10

Ensures radiation safety program that protects all persons

Maintains radiation-monitoring records

Provides counseling for individuals

Back 10

Radiation safety officer

Front 11

NCRP recommendations are based on these 3 concepts

Back 11

Linear non-threshold

Risk vs benefit

ALARA

Front 12

Dose limits are stated in what units?

Back 12

Effective Dose EfD

Front 13

Dose limits (EfD) for patients?

Back 13

Eyes - 15 rem 15,000 mrem 150 mSv

Skin, foot, hand - 50 rem 50,000 mrem 5,00 mSv

Front 14

Whole body EfD limits for occupational exposures?

Back 14

Annual - 5 rem 5,000 mrem 50 mSv

Cumulative - 1 rem x age 10 mSv x age

Front 15

What is the CumEfD limit for a 48 year old RT who has been working for 25 years in radiography?

Back 15

1 rem x 48 = 48 rem

10 mSv x 48 = 480 mSv

Front 16

Nuclear Regulatory Commission regulations for embryo/fetus of pregnant women?

Back 16

.5 rem (500 mrem or 5 mSv) for entire pregnancy

Front 17

NCRP recommended dose limit for embryo of pregnant woman,

Back 17

.05 rem (50 mrem or .5 mSv) per month

Front 18

What is the part of the radiation safety program to prevent employee exposure from exceeding dose limits where as a high badge reading would trigger an investigation called?

Back 18

Action limits

Front 19

When should a worker be monitored for radiation exposure?

Back 19

When they are regularly exposed to ionizing radiation and are likely to receive more than 1/10 of the recommended dose limit

Front 20

4 types of personal monitors worn by workers?

Back 20

Film badge

OSL - optically stimulated luminescence

TLD - thermoluminescent dosimeter

Pocket ionization chamber

Front 21

Which type of dosimeter is usualky worn as a ring?

Back 21

TLD thermoluminescent dosimeter

Front 22

Which type of dosimeter is expensive and has no permanent record?

Back 22

Pocket ionization chamber

Front 23

What measures background exposure and shod be kept in a distant room or office away from radiation areas so it can be subtracted from personal monitors?

Back 23

Control monitors

Front 24

Measures exposure rate and cumulative exposure and is used in detecting leakage in an x ray room?

Back 24

Cutie pie

Front 25

Used to detect x, gamma, and beta radiation and is primarily used in nuclear medicine to locate spills?

Back 25

Geiger-muller counter

Front 26

The product of the surface area of the patient that is exposed to radiation at the skin entrance (in square centimeters) multiplied by the radiation dose at the surface (in grays)

Back 26

DAP dose area product

Gy x cm^2

Front 27

3 cardinal principles of radiation protection

Back 27

Time

Distance

Shielding

Front 28

The 3 catagories of radiation sources

Back 28

Primary

Scatter

Leakage

Front 29

Tube leakage should not exceed what amount while tube is energized at maximum technical factors?

Back 29

100 mR/hr at 1 meter from the tube.

Front 30

Lead apron

Back 30

.25 mm pb equiv

Front 31

Lead gloves

Back 31

.25 mm pb equiv

Front 32

Thyroid shield

Back 32

.5 mm pb equiv

Front 33

Gonad shielding should always be used when the gonads are in or within how far from a proper collimated beam?

Back 33

5 cm

Front 34

To reduce ESE the following SSD should be used

Back 34

Stationary units - 38cm or 15in

Mobile units - 30cm or 12in

Front 35

Accuracy of PBL positive beam limitation (automatic collimation) should bot exceed what amount of the SID?

Back 35

2%

Front 36

Misalignment of collimated area to IR should not exceed how much of SID.

Back 36

2%

Front 37

Fluoroscopy beam limitation length and width of beam at image receptor should not exceed visible image area by more than how much?

Back 37

3%

Front 38

Describe total tube filtration.

Back 38

Equioment that operates above 70 kVp should be a minimum of w.5 mm al equivalent to achieve a minimum HVL of 2.3 al at 80 kV.

Front 39

Describe total tube filtration.

Back 39

Equioment that operates above 70 kVp should be a minimum of w.5 mm al equivalent to achieve a minimum HVL of 2.3 al at 80 kV.

Front 40

3 ways to reduce beam intensity for fluoroscopy

Back 40

Use high kV to minimize mA

When not needed, remove grid

Avoid magnification and high dose modes

Front 41

On manual mode or fluoroscopy equipment with optional high dose control exposure must not exceed how much at the point where beam enters patient?

Back 41

5R/min

Front 42

On AEC equipment, exposure must not exceed how much at the point where the beam enters the patient?

Back 42

10R/min

Front 43

High dose control for fluoroscopy, exposure must exceed what?

Back 43

20R/min

Front 44

3 requirements for high dose operation

Back 44

Special means to activate

High dose switch requires continuous manual activation by operator

A continuous audible signal during high dose operation

Front 45

ESE for average fluoro exam

Back 45

3R/min

Front 46

A fluoro unit emits 5R/min. What is the patient exposure for a BE that is conducted and requires 3.5 min fluoro time?

Back 46

5R x 3.5min = 17.5R