RAD-142 Radiologic Biology - Ch. 4

Three materials for the three filters in an OSL dosimeter

1.Aluminum 2.Copper 3.Tin

Three types of radiation survey instruments for area monitoring

1.Cutie Pie 2.Proportional Counter 3.Geiger-Muller Tube

Three anatomical exposure locations which are listed on each department employee's Personnel Monitoring Report

1.Deep 2.Eye 3.Shallow

Three radiation factors which can be read from a film badge dosimeter

1.Direction from which radiation was received 2.Scatter (fuzzy image) 3.Single exposure (sharply defined image)

Four disadvantages of pocket ionization chambers

1.Expensive 2.Inaccurate if not read daily 3.Can be discharged if subjected to mechanical shock 4.Not a legal permanent record

Four types of personnel dosimeters

1.Film badges 2.Optically stimulated luminescence dosimeters (OSL) 3.Pocket ionization chambers 4.Thermoluminescent dosimeters (TLD)

Three disadvantages of TLD's

1.High cost 2.Can be read only once 3.Calibrated TLD's must be prepared and read with each group of TLD's when they are processed

Six characteristics of personnel dosimeters

1.Lightweight 2.Easy to carry 3.Durable (normal use) 4.Detect/record small and large exposures consistently 5.Outside influences should not affect performance 6.Inexpensive

Four advantages of a TLD over the film badge dosimeter

1.More accurate 2.TLD not afffected by temperature, humidity, pressure changes 3.May be worn up to 3 months 4.Is reusable

Three parts of the film badge dosimeter

1.Plastic film holder 2.metal filters 3.film packet

Three main components of a pocket ionization chamber

1.Two electrodes (+ and -) 2.Quartz fiber 3.Special charging unit

Three types of ionizing radiation which can be monitored by film badge dosimeters

1.X-ray 2.Gamma 3.Low-energy beta

Range of radiation intensities which can be measured and recorded by the cutie pie meter

1mR/hr to several thousand milliroentgens per hour

Most common amount of time that an OSL dosimeter is worn for

2 months

Photon energy level at which film badge dosimeters are most sensitive

50KeV (anything above or below, sensitivity decreases)

Filter in the OSL dosimeter which offers the least amount of absorption

Aluminum

Two metals used for the metal filters in a film badge dosimeter

Aluminum and Copper

Material which is used in the detector of an OSL dosimeter

Aluminum oxide detector

Two types of Geiger-Muller tube radiation survey devices

Area room monitors and Portable survey instruments

Sensitivity range per month of film inside the film badge dosimeter

As low as 0.1mSv (10Rem) up to 5000mSv (500Rem)

Proper placement of a second dosimeter if and when it is required

At waist level (beneath lead apron if lead is worn)

Proper placement of a dosimeter when not using a lead apron

Attached to the clothing at the from of the body at collar level (approximately at thyroid level)

Warning system built into the Geiger-Muller detector when ionizing radiation is detected

Audible sound system

Beginning and lifespan of a radiation worker's record of radiation exposure

Begins at clinical, and follows the person from job to job

Function of the control badge

Comparison with the remaining film badges in the same batch after return to the monitoring company for processing

Filter in the OSL dosimeter which offers the most amount of absorption

Copper

What the employer must provide to the employee upon termination of employment

Cumulative personnel monitoring radiation report

Alternate name for the Ionization chamber type Survey Meter (gas-filled)

Cutie Pie

Type of radiation survey device that can measure radiation exposure rates over a wide range and determine cumulative radiation exposure over a period of time

Cutie Pie

Instrument used to measure the density on film

Densitometer

Type of film which is most similar to a film badge dosimeter

Dental film

Two radiation factors measured by a densitometer

Dose and density

One factor which either film badge or OSL dosimeters cannot determine

Exposure on the day of occurence

Type of personnel dosimeter used for monitoring occupationally exposed imaging personnel

Film badges

Type of radiation survey instrument used to indicate the presence of radiation above background radiation

Geiger-Muller (GM) Tube

Type of radiation survey device that does not directly supply a cumulative radiation reading

Geiger-Muller Tube

Primary portable gas-filled radiation survey instrument used for area monitoring in nuclear medicine

Geiger-Muller detector

Name for the laser readout from an OSL dosimeter

Glow Curve

What causes possible investigation of the employee based on their personnel monitoring report

If the numbers are higher than expected

What causes monitoring to be required for radiation workers

If they are at risk for of receiving 10% or more of their annual exposure of 50mSv (5Rem) in a year

Biggest advantage of a pocket ionization chamber

Immediate exposure reading

Where the control badge should be stored

In a radiation-free area with an optical density of zero

Two main survey instruments used to measure x-ray exposure in radiology

Ionizing chambers and Cutie Pie detectors

What is used to read an OSL dosimeter

Laser light at selected frequencies

Material located on the outside of the film packet on a film badge dosimeter

Light free envelope

Sensing material used for TLD (thermoluminescent dosimeter)

Lithium fluoride powder or small chips

Letter designation for monthly sensitivity reporting for a film badge dosimeter

M

How radiation survey instruments work

Measure either the total quantity of electrical charge or the rate at which the electrical charge is produced

Basic function of a film badge dosimeter

Metal filters produce a range of shadows to be evaluated as radiation doses

Can a film badge dosimeter be damaged if it is dropped?

No

Type of pocket dosimeter which requires a special accessory electrometer to read the device

Non self-reading pocket dosimeter

Most common type of device for monitoring diagnostic imaging exposure

OSL dosimeter

What the densitometer measures on the film from a film badge dosimeter

Optical density, or the intensity of light transmitted through a given area of the dosimetry film

Type of dosimeter which provides the best features of traditional and TLD's

Optically Stimulated Luminescence Dosimeter (OSL)

Main advantage of the film badge

Permanent legal record of personnel exposure

The monitoring of radiation exposure to any person who is occupationally exposed to ionizing radiation

Personnel Dosimetry

Personnel dosimeter which is both uncommon in x-ray use and resembles a fountain pen

Pocket Dosimeter

Most sensitive type of personnel dosimeter

Pocket Ionization Chamber or Pocket Dosimeter

Gas-filled radiation survey instrument which has no purposeful use in diagnostic radiology

Proportional Counter

Person who receives and reviews film badge personnel monitoring report

Radiation Safety Officer (RSO)

Two types of Pocket Ionization Chambers

Self-reading and Non self-reading

Sensitivity of the Geiger-Muller detector

Sensitive enough to detect individual particles or photons

Material used to back the film inside the film badge dosimeter

Sheet of lead foil to absorb scatter which comes from behind the dosimeter

Most important requirement for radiation survey instruments

Should interact with ionizing radiation in a manner similar to human tissue

Name for the second monitor for exams requiring the hands to be in the primary beam

TLD Ring (thermoluminescent dosimeter)

Equipment used to measure the amount of ionizing radiation which a TLD badge has been exposed

TLD analyzer

Two factors which can cause fog on a film badge dosimeter

Temperature and humidity

Person responsible for passing on personnel monitoring report to new employer when changing employment

The radiation worker to whom the report pertains

Type of dosimeter which contains a crystalline form (powder or small chips) of lithium fluoride

Thermoluminescent Dosimeter (TLD)

Reason for film holder of the film badge to have a low atomic number

To filter out low-energy x-rays

Purpose of personnel dosimeter

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

Proper placement of a dosimeter when using a lead apron

Worn outside the apron at collar level to measure exposure to the unprotected head, neck and eye

Can a film badge dosimeter report the difference between the types of radiation and their energies?

Yes

OSL sensitivity reading accuracy

as low as 1mRem for x-ray

Amount of time an OSL dosimeter can be worn for

up to 1 year

How lithium fluoride works in a TLD

when irradiated, LiF molecule becomes excited and traps electrons, then heated which causes electrons to release, energy emitted is equal to the difference between the electron binding energy

Two types of radiation which can be measured and recorded by the cutie pie meter

x-ray and beta radiation