UNIT 2: Radiation Monitoring Flashcards by R X

When is personnel monitoring of radiation required?

if occupational worker is likely to receive 10% or more exposure of annual limit

How well did you know this?

Not at all

Perfectly

What is the annual occupational effective dose limit?

50 msv (5000 mrem/5rem)

How well did you know this?

Not at all

Perfectly

Identify the purposes and non purposes of personnel dosimeters

• Purposes: indication of working habits and conditions, determines occupational exposure
• Nonpurposes: does not protect wearer from exposure

How well did you know this?

Not at all

Perfectly

Describe how the personnel monitoring device should be worn: with an apron, without an apron, if radiographer is pregnant

• With an apron: at collar level, outside of apron approximate dose to skin, eyes, thyroid
• Without an apron: at collar level, monitors dose to thyroid, head (eyes), neck (skin)
• If the radiographer is pregnant: 1 at waist level under the lead, monitors dose to protected fetus and 1 at the collar

How well did you know this?

Not at all

Perfectly

Where is a common location for extremity badges to be worn?

ring on finger

How well did you know this?

Not at all

Perfectly

Identify the 3 types of personnel dosimeters currently used to measure individual radiation exposure.

OSL, TLD, lonization chamber

How well did you know this?

Not at all

Perfectly

What does OSL stand for?

Optically Stimulated Luminescence

How well did you know this?

Not at all

Perfectly

OSL sensing material

Aluminum Oxide

How well did you know this?

Not at all

Perfectly

How does the OSL dosimeter work?

Read out by using laser light

How well did you know this?

Not at all

Perfectly

OSL advantages and disadvantages

•Advantages: may be worn up to a year, light weight, durable, easy to wear, can be reread
•Disadvantages: occupational radiation exposure is recorded only in the body area where the device is attached

How well did you know this?

Not at all

Perfectly

What is the purpose of the control monitor/badge?

Serve as a basis for comparison with the remaining OSL dosimeters after they have been returned to the company for processing

How well did you know this?

Not at all

Perfectly

Where should the control monitor/ badge be kept?

radiation free area within an imaging facility

How well did you know this?

Not at all

Perfectly

How is the read out of personnel monitoring badges adjusted if the control badge reads higher than zero?

The reading must be subtracted from each of the remaining OSL’s in the batch to ensure accuracy

How well did you know this?

Not at all

Perfectly

How can occupation effective dose be determined if a personnel monitoring device is not worn?

they will get an estimated amount based on the occupational worker’s history

How well did you know this?

Not at all

Perfectly

What unit of measurement is commonly used on the radiation dosimetry report?

mRem, but can be requested in mSv

How well did you know this?

Not at all

Perfectly

What time frames are reported on the personnel monitoring report?

-Monthly, quarterly, yearly, lifetime equivalent

How well did you know this?

Not at all

Perfectly

Which personnel dosimeter can be reread?

OSL

How well did you know this?

Not at all

Perfectly

Which personnel dosimeter can only be read once?

TLD

How well did you know this?

Not at all

Perfectly

Which personnel dosimeter is most common?

OSL

How well did you know this?

Not at all

Perfectly

Which personnel dosimeter is an extremity dosimeter?

TLD

How well did you know this?

Not at all

Perfectly

Explain what “deep”, “eye”, and “shallow” indicate on a report and which filters are associated with each.

• Eye: radiation equivalent dose to the lens of the eye at a tissue depth of 0.3cm (Tin OSL)
• Shallow: the external exposure of the skin or extremity at a tissue depth of 0.007 cm averaged over an area of 1cm (Aluminum OSL)
• Deep: external whole body absorbed dose determined by a personnel dosimeter at a tissue depth of 1cm (Copper OSL)

Define “M” on the dosimeter report

an equivalent dose below the minimum measureable radiation quantity was recorded during that time

In well-structured facilities, who receives and reviews the dosimeter monitoring report?

Radiation safety officer

T to F: OSL dosimeters can be reread

True

What does TLD stand for?

Thermoluminescent Dosimeter

TLD sensing material

lithium fluoride

How do TLD’s work?

Heat read out

TLD advantages and disadvantages

•Advantages: accurate and reliable, small and light weight, cost effective because it can be reused •Disadvantages: readings will be lost if not carefully recorded, readout process destroys information stored in TLD which means it cannot serve as a permanent legal record of exposure

How does the Personnel Digital lonization Chamber (DIS) work

Immediate measurement and read out available when connected to the computer via USB

Personnel Digital lonization Chamber (DIS) advantages and disadvantages

• Advantages: instant access to data, lightweight, durable • Disadvantages: radiation exposure cannot be determined if dosimeter is not regularly used

Which personnel device(s) are generally "read" every 3 months?

OSL and TLD

Which personnel device(s) are generally "read" daily?

Personnel Digital lonization Chamber

Which radiation survey instruments measure both radiation exposure & exposure rate?

lonization chamber-type survey meter (cutie pie), Proportional Counter

Which radiation survey instruments measure exposure rate only?

GM survey meter

What is known as the “Cutie Pie”

lonization Chamber-Type Survey Meter (gas filled radiation survey instrunment)

lonization Chamber-Type Survey Meter radiation detected

• X-radiation • Gamma radiation

What is the lonization Chamber-Type Survey Meter used for?

measures radiation exposure and exposure rate to help determine accuracy of radiographic equipment and presence of radiation

lonization Chamber-Type Survey Meter advantages and disadvantages

•Advantages: the ability to measure a wide range of radiation exposure within a few seconds over a broad expanse of radiation energies •Disadvantages: delicate detector of the unit, without adequate warm-up time it can produce an inaccurate reading

Which is the instrument of choice when determining exposure rates from patients containing therapeutic doses of radioactive material and measuring rates in radioisotope storage facilities?

lonization Chamber-Type Survey Meter

Proportional Counter radiation detected

alpha and beta

Proportional counter uses

No useful purpose

Geiger-Muller Survey Meter radiation detected

Sensitive, able to detect individual particles except alpha particles. Can also detect photons.

Geiger-Muller Survey Meter uses

• can detect area contaminated by radioactive material • locate radioactive source

Geiger-Muller Survey Meter advantages and disadvantages

•Advantages: offers rapid monitoring, scan radiation barriers and detect defects •Disadvantages: unless corrected, provides wrong readings, likely to saturate or jam when placed in pulsed high intensity radiation area

Which survey meter is most used in Nuclear Medicine

GM survey meter

Which type of equipment can be used to measure radiation output from radiographic & fluoroscopic equipment?

Ionization Chamber-Type Survey Meter

List the annual measurements that must be performed as required by the state, federal, and healthcare accreditation organizations for radiographic/ fluoroscopic devices

•X-ray output in Gy or mGy •Fluoroscopic radiation entrance rates in mSv/min or R/ min •kVp setting accuracy •Exposure timer exactness •Half-value layers or beam quality

Ionization chambers are used to measure radiation output from which unit?

X-ray unit and Fluoroscopic unit

What is the radiation safety officer responsible for

Reviewing personnel reports and maintaining a radiation safety program

To keep radiation exposure ALARA, most health care facilities issue dosimeter devices when personnel could receive approximately:

1% of the annual occupational EfD limit