ALARA principles, shielding, and dose limit concepts tested on radiologic technology certification exams.
34 cards · basic cards · AI-written, checked twice. Edit anything.
- What does ALARA stand for?
- As Low As Reasonably Achievable
- What are the three main methods to reduce radiation exposure according to ALARA?
- Time, Distance, and Shielding
- How does reducing time spent in a radiation field affect dose received?
- Dose is directly proportional to time; less time equals less dose
- What is the inverse square law in radiation protection?
- Radiation intensity decreases by the square of the distance from the source
- If you double the distance from a radiation source, by what factor is the dose reduced?
- The dose is reduced by a factor of 4
- What is the primary purpose of lead shielding in radiologic protection?
- To attenuate (reduce) radiation by absorbing photons
- What is a primary barrier?
- A barrier positioned directly in the path of the primary X-ray beam
- What is a secondary barrier?
- A barrier that protects against scattered radiation and leakage radiation
- What is the annual occupational dose limit for radiation workers recommended by the NCRP?
- 5,000 mrem (50 mSv) per year for the whole body
- What is the public dose limit recommended by the NCRP?
- 100 mrem (1 mSv) per year for the general public
- What dose limit applies to a declared pregnant worker?
- 500 mrem (5 mSv) for the entire pregnancy once pregnancy is declared
- What is the recommended monthly dose limit for the embryo or fetus of a declared pregnant worker?
- Approximately 50 mrem (0.5 mSv) per month
- What is the standard thickness of a lead apron worn for radiation protection?
- 0.5 mm (one-half millimeter) of lead equivalency
- What anatomical area does a thyroid collar protect?
- The thyroid gland from direct and scattered radiation
- What is the annual dose limit to the lens of the eye?
- 5,000 mrem (50 mSv) per year in occupational settings