Module 7 (Measuring and Minimizing Radiation) Flashcards
What is the most current method of measuring radiation exposure?
Absorbed Dose (D), measured in Gray (Gy).
How is Absorbed Dose (D) measured?
It is measured using ionization chambers and quantified as joules per kilogram (J/Kg), expressed in Gray (Gy).
What does Effective Dose (E) take into account?
Absorbed dose and tissue types exposed, considering radiosensitivity, cancer, and genetic risk.
What is the unit for Effective Dose (E)?
Sievert (Sv).
What is the estimated increase in lifetime incidence of cancer per Sievert (Sv)?
5% per Sievert (Sv).
What is the purpose of exposure monitoring devices?
To quantify and track radiation exposure to personnel over time.
Name three types of personal radiation monitoring devices.
Film badges, Thermoluminescent Dosimeters (TLD), and Optically Stimulated Luminescence (OSL) devices.
Where should a dosimeter be worn when a lead apron is used?
Beneath the apron at waist level.
How do Thermoluminescent Dosimeters (TLDs) work?
They store energy from radiation, which is later released as light when heated. The light is measured to determine exposure.
How do Optically Stimulated Luminescence (OSL) devices work?
A laser stimulates the material, releasing stored energy as light, which is then analyzed to determine radiation dose.
What is the annual whole-body dose limit for radiation workers?
20 mSv per year, averaged over five years (100 mSv in 5 years, with a max of 50 mSv in a single year).
What is the annual whole-body dose limit for members of the public?
1 mSv per year.
According to SC35, what must all radiation workers do?
Wear dosimeters, maintain training, monitor personal exposure, follow ALARA principles, and participate in quality assurance (QA) processes.
What does ALARA stand for?
“As Low As Reasonably Achievable” – minimizing exposure to radiation.
What is Dose Area Product (DAP)?
A measure of patient exposure that multiplies air kerma by the exposure field size (measured in mGy-cm²).
What is the Quality Factor (QF) for X-rays, Gamma Rays, and Beta Particles?
1 (lowest ionizing radiation quality factor).
What is the SC35 requirement regarding personal exposure records?
They must be maintained for the lifetime of the facility.
What is the SC35 recommendation for personnel in high-risk areas like interventional radiology?
Use lead glasses, thyroid shields, and wear a second OSL at the collar level outside the apron.
