Week 5- Radiation Monitoring

Question 1

What is personnel dosimetry?

Answer 1

The monitoring of equivalent dose to any person occupationally exposed on a regular basis to ionizing radiation

Question 2

What is one purpose of personnel dosimetry?

Answer 2

Ensures that occupational radiation exposure levels are kept well below annual effective (EfD) limits

Question 3

When is personnel monitoring required?

Answer 3

Whenever radiation workers are likely to risk receiving 10% of the annual occupational Efd limit in a single year as a consequence of their work

Question 4

What is 10% of the annual occupational EfD limit?

Answer 4

50 mSv (5 rem)

Question 5

When do most healthcare facilities issue personnel dosimetry devices?

Answer 5

When personnel could receive 1% of annual EfD limit in any month

Question 6

What is 1% of annual occupational EfD limit per month?

Answer 6

.5 mSv (50 mrem)

Question 7

What is the first purpose of personnel dosimeters?

Answer 7

To provide an indication of the working habits/conditions of diagnostic imaging personnel

Question 8

What is the second purpose of personnel dosimeters?

Answer 8

Determines occupational exposure by detecting and measuring the quantity of ionizing radiation to which the dosimeter has been exposed

Question 9

What is a common misconception of personnel dosimeters?

Answer 9

Does not protect the wearer from exposure, it is only capable of detecting and measuring ionization

Question 10

During routing radiographic procedures where should a dosimeter be worn?

Answer 10

Primary personnel dosimeter should be attached to the clothing on the front of the body at collar level

Question 11

When a protective apron is used where should a dosimeter be worn?

Answer 11

Should be work outside the apron at collar level on the anterior surface of the body

Question 12

What is the primary dosimeter measuring when its placed at collar level?

Answer 12

Measuring the dose to the thyroid, head and neck

Question 13

When wearing an apron where should a secondary dosimeter be placed?

Answer 13

Under the apron at waist level

Question 14

For pregnant personnel, where should the dosimeter be worn?

Answer 14

• Primary dosimeter worn at collar level
• Secondary dosimeter work at abdominal level

Question 15

What is a type of extremity dosimeter?

Answer 15

A thermoluminescent dosimeter (TLD) ring badge

Question 16

What is the necessity of a TLD ring?

Answer 16

A second monitor that should be worn when the performing radiographic procedures that require hands to be near primary x-ray beam

Question 17

What does the laser etched cover of the TLD ring contain?

Answer 17

Personal identification

Question 18

What record should radiation exposure be a part of?

Answer 18

Part of the employment record of all workers

Question 19

What values are represented in the employment record?

Answer 19

Values represent the average annual EfD to the whole body

Question 20

What are characteristics of personnel dosimeters?

Answer 20

• Lightweight and easy to carry
• Made of materials durable enough to tolerate normal daily use
• Able to detect and record both small and large exposures in a consistent manner
• Unaffected by outside influences like weather or humidity
• Are reasonably inexpensive to purchase and maintain
• Permit healthcare facilities to use large numbers of monitors in a cost-effective manner

Question 21

What are the three most current types personnel dosimeters?

Answer 21

• Optically stimulated luminescence dosimeter (OSL)
• Direct Ion Storage (DIS)
• Extremity dosimeter (TLD)

Question 22

What is the most common device used for monitoring occupational exposure?

Answer 22

Optically stimulated luminescence dosimeter (OSL)

Question 23

What does an OSL dosimeter contain?

Answer 23

Aluminum oxide detector

Question 24

What energy discrimination does an OSL dosimeter contain?

Answer 24

Filters made of aluminum, tin and copper

Question 25

What is the sensitivity level of OSL dosimeters?

Answer 25

Accurate reading as low as 10 uSv

Question 26

What are the advantages of OSL dosimeters?

Answer 26

- Lightweight, durable and easily worn - Preloaded packet - Allows for reanalysis

Question 27

What are the disadvantages of OSL dosimeters?

Answer 27

- Occupational exposure is recorded only in the body area where the device is attached - Exposure cannot be immediately determined

Question 28

How do OSL dosimeters compare to other devices?

Answer 28

Its the 2nd most sensitive

Question 29

What are the terms of use for an OSL dosimeter?

Answer 29

Can be used up to 1 year, but its normally worn for 1-3 months

Question 30

What type of detector does a TLD contain?

Answer 30

Lithium fluoride crystals

Question 31

How does the detector work in a TLD?

Answer 31

The photon energy is stored until the detector is "read" by heading it

Question 33

What are pocket ionization chambers?

Answer 33

Pocket dosimeters that resemble a fountain pen

Question 34

What type of detector does a pocket ionization chamber contain?

Answer 34

Ionization chamber with a built in electrometer

Question 35

What is the sensitivity level of a pocket ionization chamber?

Answer 35

The most sensitive type of

Question 36

What are the terms of use of a pocket ionization chamber?

Answer 36

Cannot be used for long-term monitoring. They provide an immediate readout and are used for short term monitoring in high dose situations

Question 37

How is a Direct Ion Storage Dosimeter set up?

Answer 37

Small ionization gas filled dosimeter is connected to a solid state device with EEPROM

Question 38

How does a DIS dosimeter work?

Answer 38

Radiation ionizes the gas in the ion chambers and the electric charge stores it until its “read-out”

Question 39

How is a DIS read out?

Answer 39

It’s read out by physically connecting it to a device where the data can be stored electronically or via an app

Question 40

What are the advantages of DIS?

Answer 40

- Instant access to data - Lightweight and durable - Can be dropped/scratched without harming the device

Question 41

What are the disadvantages of DIS dosimeter?

Answer 41

Must be worn to be accurate

Question 42

When a radiation worker changes jobs, what happens to their dose record?

Answer 42

It transfers to the new employer

Question 43

What are the 3 categories of radiation survey instruments?

Answer 43

- Those without a readout scale - Those with a readout scale - Ionization-chamber based

Question 44

What is the most common detector in radiation survey instruments?

Answer 44

Geiger-Muller tube detector

Question 45

What does the simplest form of radiation survey instruments provide?

Answer 45

Indicates the presence of radiation above background level

Question 46

What is one limitation of radiation survey instruments?

Answer 46

They do not provide a cumulative exposure reading

Question 47

What are the types of instruments used for radiation survey?

Answer 47

Portable devices that can detect and measure radiation in the environment

Question 48

What do radiation survey instruments respond to?

Answer 48

Respond to the charged particles that are produced by the radiation interacting with and ionizing the gas in the detector

Question 49

What do radiation survey instruments measure?

Answer 49

Measure either the quantity of electrical charge resulting from the ionization of gas or the rate at which the electrical charge is produced

Question 50

What do gas filled detectors include?

Answer 50

- Ionization chamber type survey meter (cutie pie) - Proportional counter - GM survey meter

Question 51

What are the requirements for radiation survey instruments?

Answer 51

- Portable - Durable - Reliable - Interacts with radiation like tissues do - Detect all common types of ionizing radiation - Is not impacted by energy of the radiation - Cost effective - Calibrated annually to ensure accurate operation

Question 52

How can ionization chambers be used to measure X-ray exposure?

Answer 52

Can be used to measure the radiation output from both radiographic and fluoroscopic X-ray equipment

Question 53

What is the cutie pie ionization chamber used for?

Answer 53

Radiation protection surveys

Question 54

What needs to be calibrated periodically to meet state and federal dose evaluation standards?

Answer 54

The ionization chamber and electrometer systems

Question 55

How do medical physicists use ionization chambers?

Answer 55

Ionization chambers are connected to electrometers to perform stand measurements required by state, federal and health orgs for radiographic devices

Question 56

What is the primary portable radiation survey instrument used in nuclear medicine?

Answer 56

The Geiger-Muller survey meter

Question 57

What does the Geiger-Muller Survey meter effective in?

Answer 57

Effective to detect radioactive nuclei or photons to small amounts of radiation

Question 58

What is the Geiger-Muller survey meter used to detect?

Answer 58

Used to detect radiation from spills, lost radioactive sources, etc

Question 59

How does the Ginger-Muller survey meter work?

Answer 59

It has an audible signal and a meter to measure the presence of radiation

Question 60

What is the proportional counter used for?

Answer 60

As a lab instrument to measure alpha and beta particles, NOT for diagnostic imaging