Chapter 1 and 6 Flashcards
Personnel monitoring devices include all of the following except the ____ dosimeter.
scientillation
Which instrument detects the presence of radiation rather than measuring it?
Geiger Muller
Diagnostic radiology personnel may receive an annual dose limit of:
5 rem
Dose limits are based on a ________________ dose-response relationship to radiation.
linear; nonthreshold
The dose limit for the general public is _______ the dose limit for occupational exposure
1/10
What factors can decrease the dose to the limited operator?
- time
- distance
- shielding
The unit of the SI system used to measure the equivalent dose is the:
Sievert
The SI unit for measuring absorbed dose is the
Gray
What does ALARA stand for? Why is this concept the guiding principal to the field of radiology?
- As low as reasonable achievable
- this concept emphasizes the protection against radiation. To minimize the ionizing radiation exposure as much as possible to avoid occupational or patient dose.
The unit commonly used to report the effective dose to occupational workers in the United States is
mSv (millisievert)
What are the units of measurement for Exposure, Absorbed Dose and Equivalent/ Effective Dose? List both the conventional and SI units for each.
- Exposure =Roentgen (R) / 2.58 x 10-4 C/kg
- Absorbed Dose = Rad (rad) / 0.01 Gy
- Equivalent/ Effective Dose = Rem (rem) / 0.01 Sv
What are the types of dosimeters? Which is the most common and why?
Personell Dosimeters
- Film Badges
- TLD (Thermoluminescent dosimeter)
- OSL (optically stimulated luminescence)
- pocket dosimeters
- most common would-be film badges
- they’re inexpensive
- simple to use
Where should dosimeter badges be worn? Where should fetal dosimeter badges be worn?
- dosimeters should be worn at the collar level
- fetal dosimeters must be worn at the abdominal area
What is declaration of pregnancy? How is it executed?
- declaration of pregnancy is when the worker voluntarily reveals her pregnancy to the employer.
- The RSO (radiation safety officer) will then council with her to follow proper radiation protection
- can be limited to exams
- cannot be expelled from work
- minimizing the radiation exposure as much as possible
What is the effective annual dose limit for radiology personnel?
5 rem*
Which dose-response relationship are dose limits and radiation protection based upon?
dose limits are based on linear nonthreshold relationships
Which governing body is responsible for establishing dose limits and protection guidelines?
nuclear regulatory commission (NRC)
What is a dosimetry report? Who is responsible for monitoring it?
- dosimetry report is film badges, TLD, OSL, and pocket dosimeters being collected every month
- The RSO (radiation safety officer) monitors the reports to retrieve and distribute to employees
What is the difference between a personnel monitor and a field-survey instrument?
- personnel monitors measure the radiation a worker is being exposed to
- field survey are devices used to detect and measure the radiation in an area
What are the guiding principals of reducing the possibility of radiation exposure?
Cardinal principles
- time
- distance
- shielding
What are the dose limits for occupation exposure for Whole-Body? Include both convention and SI units
5rem (50mSv)
What are the dose limits for occupation exposure for Lens of Eyes? Include both convention and SI units
15 rem (150mSv)
What are the dose limits for occupation exposure for Skin/Extremities? Include both convention and SI units
50rem (500mSv)
What are the dose limits for occupation exposure for Whole-Body Cumulative? Include both convention and SI units
Age x 1rem (Age x 10 mSv)
What are the dose limits for occupation exposure for Fetus? Include both convention and SI units
10 month/280 days = 0.5rem(5mSv)
one month/28 days = 0.05rem (0.5mSv)
What are the dose limits for occupation exposure for Public Exposure? Include both convention and SI units
infrequent exposure = 0.5 rem (5 mSv)
frequent exposure = 0.1 (1 mSv)
