Occupational Radiation Dose Management

What is the percentage of those receiving less than 1 mSv/yr for radiologic personnel?

88%

Fluoroscopic units often have the x-ray tube under the table with the image intensifier tube over the top of the table to:

Lower the dose to personnel

What is the unit of measurement that expresses the occupational exposure or the dose-effect relationship?

mrem

Occupation exposure that occurs during fluoroscopy and mobile radiography accounts for what perfect of a technologist’s radiation dose?

95%

What does ALARA stand for?

As Low As Reasonable Achievable

True or false: The cumulative dose limit for a 25 year old radiographer is 0.25 Sievert

True

The annual dose limit for the general public (infrequent exposure) is _____ mSv

5

The dose limit for the thyroid, skin, hands, and feet of a radiographer is _____ mSv

500

Personnel exposures in CT are ______ compared to those in fluoroscopy as can be demonstrated with isoexposure lines

Low

If the radiation dose limit for the lens of the eye is 150 mSv for a radiographer, then what is it for the general public (public exposure)?

15 mSv

NCRP #116: Public exposure-infrequent exposure

5 mSv

NCRP #116: Education and training exposure-annual effective dose

1 mSv

NCRP #116: Occupational exposure-thyroid, skin, hands, and feet

500 mSv

NCRP #116: Students younger than 18 years of age

1 mSv

NCRP #116: Occupational exposure- annual effective dose

50 mSv

NCRP #116: Public exposure- frequency exposure

1 mSv

NCRP #116: Occupational exposure- lens of the eye

150 mSv

If the dose is kept below the recommended guideleines, the likelihood of an adverse radiation effect to the occupationally exposed person is very _______

Remote

True or false: radiologists generally receive slightly higher exposures than radiographers during fluoroscopy exams

True

True or false: average exposures in most facilities are less than 1 mSv/year

True

Those receiving occupational radiation exposure of less than 1 mSv/year is ______%

88%

The highest occupational exposure of diagnostic x-ray personnel occurs during:

• fluoroscopy

• mobile radiography

Fluoroscopic exams and mobile radiography account for at least ____% of the radiologic tech’s occupational radiation exposure

95%

During fluoroscopy, why is the tube on top not recommended?

Can increase dose to the operators eyes up to 100x

Would there be any advantage for the x-ray tube on top?

Image quality

True or false: extremity monitoring (finger ring) must be provided for interventional radiologists

True

Does this describe mammography: personnel exposures are high due to higher kVp utilized

No

Does this describe mammography: a long exposure cord and a conventional wall are sufficient for protection

Yes

Does this describe mammography: always requires protective lead shielding for dedicated mammography room

No

True or false: radiation level isoexposure lines are low in CT compared to fluoroscopy as the CT x-ray beam is finely collimated and only secondary radiation is present in the exam room

True

Scrub nurses and other personnel in the OR should not be concerned due to the fact that their occupational exposure is near ______

Zero

If a friend of relative of the younger patient, who is the best person (1st choice) to help hold the patient

Elderly male is the best choice

True or false: students should never hold a patient during an exam

True

Annual dose limits for occupationally exposed individuals are valid for while type of radiations?

Beta, gamma, x-ray

True or false: there are dose limit recommendations for patients

False

Occupational radiation monitoring is required when there is any likelihood that an individual will receive more than _____ of the recommended dose limit

1/10th

What is the minimal requirement for all lead aprons and gloves?

0.25 mm Pb eq

What does the NCRP recommend is the minimal requirement for all lead aprons and gloves?

0.5 mm Pb eq

What is the percentage of x-ray attenuation at 100 kVp and 0.5 mm lead equivalent?

75%

All female occupationally exposed to ionizing radiation will be give a copy of the NRC document

NRC regulatory guide 8.13

True or false: declaration of pregnancy is completely voluntary and can be accomplished by verbally letting your supervisor know

False (must be in writing)

List 4 advantages for the female radiographer deciding to declare her pregnancy in writing:

1. RSO reviews exposure history and protection policies with tech

2. Tech will receive a separate monthly fetal monitoring badge

3. Adjustments to the NCRP #116 dose limit recommendations are made

4. Typically issues a wrap around apron and use of portable lead barriers

Film badge

• A reading of “M” indicates that you have an exposure reading below 0.1 mSv

• Disadvantage is that is susceptible to heat, humidity, and light leaks

TLD

• When heated, the lithium fluoride crystals release energy as visible light (thermoluminescence)

• Contains either lithium fluoride or calcium fluoride crystals

OSL

• Dose measurement range is very wide: 0.01 mSv to 10 mSv

• Contains filters composed of aluminum, tin, and copper as well as a thin strip of aluminum oxide

Pocket dosimeter

• Resembles a fountain pen and provides an immediate readout for emergency situations

• Bumping or shock to unit can cause false high readings

True or false: In order to provide an exposure reading, personnel monitoring devices utilize either ionization, luminescence, or thermoluminescence

True

True or false: It is an acceptable practice today to do a quarterly blood cell count as a way to measure occupational exposure

False

A film badge is similar to dental x-ray film and measures doses as low as _______

0.1 mSv

Film badges utilize filters made of _______ and ______ which measure the intensity and type of radiation striking the film badge

Aluminum and copper

List 3 advantages of the film badge:

• Simple to use

• Inexpensive

• Provide an permanent record

This type of personnel monitoring devices contains lithium fluoride or calcium fluoride crystals

Thermoluminescent dosimeter (TLD)

What are advantages of the TLD?

• Can be made very small

• Have a low exposure limit of 0.05 mSv

This type of dosimeter has a low level of sensitivity, approximately 0.01 mSv and is especially useful for the monitoring of pregnant workers

Optically stimulated luminescence dosimeter (OSL or OSLD)

As OSL reading of “M” or minimal indicated that you have an exposure reading below ______

0.01 mSv

All of the following are advantages of OSLs except:

Are more expensive than film badges or TLDs

This is the newest type of personnel monitoring device that has a gas-filled chamber within the device and uses Bluetooth technology for transmission of report data

Direct Ion Storage Dosimeter (DIS)

List two disadvantages of pocket dosimeters:

• Does not provide a permanent legal record of exposure

• Bumping or shock to unit can cause false readings

This field survey instrument is used to detect alpha and beta radiation, is a gas-filled ionization chamber, and also referred to as a Geiger counter

Geiger-Mueller detector

This device is used in gamma cameras in nuclear medicine:

Scintillation detection device

What does an “M” or “ND” on a monthly or quarterly dosimetry report mean?

It means that there was minimal exposure or no dose