EXAM #4 (Ch. 38 Occupational Radiation Dose Management) Flashcards
Extremity monitoring must be provided for who?
Extremity monitoring must be provided for interventional radiologists.
DLs imply that if received annually, the risk of death would be less than what?
DLs imply that if received annually, the risk of death would be less than 1 in 10,000.
Current DLs are based on a _____, _____ dose-response relationship; they are considered to represent an _____ level of occupational radiation exposure.
Current DLs are based on a linear, nonthreshold dose-response relationship; they are considered to represent an acceptable level of occupational radiation exposure.
What is the equation for effective dose?
Effective dose (E) = Radiation weighting factor (Wr) × Tissue weighting factor (Wt) × Absorbed dose
The DL established for nonoccupationally exposed persons is __ of that established for the radiation worker.
The DL established for nonoccupationally exposed persons is 1/10 of that established for the radiation worker.
Each mobile x-ray unit should have a what assigned to it?
Each mobile x-ray unit should have a protective apron assigned to it.
The exposure cord on a portable x-ray unit must be at least __m long.
The exposure cord on a portable x-ray unit must be at least 2m long.
The useful beam should never be directed toward the what?
The useful beam should never be directed toward the operating console.
Occupational radiation monitoring is required when there is any likelihood that an individual will receive more than __ of the recommended dose limit.
Occupational radiation monitoring is required when there is any likelihood that an individual will receive more than 1/10 of the recommended dose limit.
The occupational radiation monitor offers what against radiation exposure?
The occupational radiation monitor offers no protection against radiation exposure!
Film badges must be worn with the appropriate side to the _____.
Film badges must be worn with the appropriate side to the front.
TLDs can be worn for intervals up to how long?
TLDs can be worn for intervals up to 1 year.
If the radiologic technologist participates in fluoroscopy, the occupational radiation monitor should be positioned where?
If the radiologic technologist participates in fluoroscopy, the occupational radiation monitor should be positioned on the collar above the protective apron.
The control monitor measures what?
The control monitor measures background exposure during transportation, handling, and storage.
What must be worn during fluoroscopy and mobile radiology?
Protective apparel must be worn during fluoroscopy and mobile radiology.
It is known that __mm lead equivalent protective aprons represent a workable compromise between unnecessary weight and desired protection.
It is known that 0.5mm lead equivalent protective aprons represent a workable compromise between unnecessary weight and desired protection.
Radiology staff should never hold what?
Radiology staff should never hold patients.
The pregnant radiologic technologist should be provided with what?
The pregnant radiologic technologist should be provided with a second personnel monitoring device.
The effective DL is __mSv/yr (__mrem/yr).
Environmental background radiation is approximately __mSv/yr (__mrem/yr).
The effective DL is 50 mSv/yr (5000 mrem/yr).
Environmental background radiation is approximately 1 mSv/yr (100 mrem/yr).
Under no circumstance should termination or an involuntary leave of absence occur as a consequence of what?
Under no circumstance should termination or an involuntary leave of absence occur as a consequence of pregnancy.
Define: NCRP
National Council on Radiation Protection and Measurements.
Define: ALARA
As Low As Reasonably Achievable.
Define: Tissue weighting factor (Wt)
A numerical value relating the relative radiosensitivity of several organs and tissues.
Define: Extremity monitor
A ring or wrist badge.
Define: Personnel monitor
A radiation dosimeter designed to measure the intensity of occupational radiation exposure (e.g. film badge, TLD, OSL).
Define: Units of x-radiation output intensity
Air Kerma Gya or mGya or mGya/mAs (mR or mR/mA or mR/mAs).
Define: Extremity DL
50 rem/yr (500 mSv/yr).
Define: Effective dose
The whole body equivalent dose of a partial body exposure that will produce the same response.
Define: Threshold dose
A radiation dose below which the response under investigation will not be observed.
Define: OSL
Optically Stimulated Luminescence.
What is the dose limit for diagnostic imaging personnel?
50 mSv/yr (5000 mrem/yr); 10 mSv × N (1000 mrem × N) cumulative where N = age.
During what two examinations can occupational radiation exposure be high?
During cardiovascular and interventional procedures, fluoroscopy and mobile radiography.
What does the value 10^−4 yr^−1 mean with regard to the NCRP recommended dose limits?
This is the risk coefficient for stochastic effects.
How do some radiation occupational groups such as nuclear medicine technologists monitor their extremity doses?
With ring and wrist badges.
What is the whole-body occupational DL for radiography students younger than 18 years of age?
1 mSv/yr (100 mrem/yr).
State the management protocol for the pregnant radiologic technologist
Counsel the pregnant technologist and provide her with an additional radiation monitor with instructions to wear it at waist level under protective apparel.
What information regarding radiation protection should be covered in regularly scheduled in-service training classes?
The cardinal principles of radiation control, dose limits, and special attention to pregnancy.
What exposure will a radiologic technologist receive while wearing a protective apron equivalent to 2 HVLs and exposed for 10 minutes at 4 m from a source with intensity of 1 mGya/hr at 1 m?
2.6 uGya.
The collar-positioned monitor of a fluoroscopist records 0.9 mSv during a month. This represents approximately what effective dose (E)?
0.045 mSv = 45 uSv.
What is the required length of the exposure cord on the mobile radiographic unit?
Two meters.
When must occupational radiation monitoring be provided?
When there is likelihood that an individual will exceed 10% of the dose limit. In practice, all radiology personnel are provided monitors.
Describe the design of occupational radiation monitors. How are they to be worn, and where on the body are they placed?
All such monitors have several detection regions filtered to identify the type and energy of the radiation. On the trunk of the body except when a protective apron is used and then at collar level above the apron.
List the exposure data that must be included in the personnel monitoring report.
Name, identifying number, dose equivalent to whole body and extremities, quarterly dose and cumulative dose.
What is an appropriate thickness for protective apparel?
Thickness of protective apparel 0.5 mm Pb; although 0.25 mm Pb is acceptable.
What procedure is used for holding patients during an x-ray examination?
Patients should not be held by radiologic personnel. Restraining devices or other persons may be recruited.
Describe the features of optically stimulated dosimetry that make it particularly effective for occupational radiation monitoring.
Shaped crystals of aluminum sulfate store energy in the form of trapped electrons after x-ray exposure. When processed, this material is stimulated by laser light, and the trapped electrons return to the ground state with the emission of shorter wavelength light. The intensity of this stimulated luminescence is directly proportional to the x-ray exposure received by the occupational radiation monitor.
What is the DL for the lens of the eye and the requirement for protective eyewear?
150 mSv/yr, and protective apparel are not required.
What is the approximate protective value of an occupational radiation monitor?
None.
Describe an appropriate radiation protection program for nursing and surgical personnel.
Monitor for a period of six months or so and if exposures occur continue the program; if not, occupational monitoring is not required. The latter is usually the case.
