1. Radiation
    Energy that comes from a source and travels through some material or through space.
  2. Ionizing Radiation
    • High energy radiation capable of producing ionization in substances through which it passes.
    • Ionization radiation can be harmful to humans. 
    • X-ray (AKA): phantom, EM energy quantum, & balance of energy.
    • The radiographer must protect all persons who come in contact with radiation.
  3. X-rays
    • Are form of electromagnetic radiation.
    • Travel at the speed of light.
    • No mass.
    • No charge.
  4. Radiation Protection
    • Purpose is to reduce exposure to staff, patients, & public as much as possible while maintaining image quality.
    • ALARA: As Low As Reasonably Achievable
    • Cardinal Priniciples of Radation Protection:  Time, Distance, and Shielding.
  5. ALARA
    As Low As Reasonably Achievable
  6. Cardinal Principles of Radiation Protection
    • Time: minimize time equals less dose. 
    • Distance: Maximize distance to prevent scatter from patient. 
    • Shielding: Always shield.
  7. Time
    • Refers to length of time an individual is exposed to ionizing radiation. 
    • Minimize time. Less time equals less dose. 
    • Time has a direct relationship to dose.
  8. Maximize
    • Increase distance reduces dose according to Inverse Square Law. 
    • Maximize distance. 
    • Primary source of occupational exposure is scatter from patient increases your distance from patient.
  9. Shielding
    • Use when it it will not obscure diagnostic information. 
    • Shielding devices: Lead aprons, thyroid shield, lead glasses, shielding helps to decrease patient dose.
  10. Specific Area Shielding
    • Ex. Gonadal Shielding. 
    • Use on patients of reproductive age. 
    • Use when gonads are in or near the useful beam (withing 5cm).
    • Use when it's use will not comprise required diagnostic information.
  11. Personnel Monitoring Devices
    • Must be worn at all times!
    • Dose measuring devices that measure or detect radiation exposure from X-rays.
    • Measure dose & energy of radiation. 
    • Must be worn on collar, outside of apron. 
    • Additional personnel monitoring device is worn by pregnant women.
  12. Protecting the Radiographer
    • ALARA
    • Cardinal Rules of Radiation Protection
    • Radiation monitoring device is Optically Stimulated Luminescence (OSL) 
    • Consists of a strip of Al Oxide, a Cu Filter, a tin filter, & an imaging filter.
  13. How the OSL works
    Al oxide is exposed to a laser light which is stimulated after use, causing it to become luminescent in proportion of the amount of radiation exposure which determines the occupational worke's exposure.
  14. Protecting the patient
    • ALRA
    • Cardinal Rules of Radiation 
    • Beam restricting devices (focus on the area with the calumniator.
    • Technical factor selection.
    • Filtration aluminum absorbs low energy photon (xrays) to improve patient dose. Low atamic number absorbs low photons to allow only high photons to go through patient.
  15. kVp and mAs
    • High kVp and low mAs equals to low PT dose.
    • Also known as technique.
  16. Ten commandments of Radiation Protection
    • 1. Understand & Apply Cardinal Principles of radiation control. 
    • 2. Do not allow familiarity to result in false security. 
    • 3. Never stand in primary beam. 
    • 4. Always wear protective apparel when not behind a protective banner.
    • 5. Always wear radiation monitor & position it outside lead and collar. 
    • 6. Never hold a PT. Have parents or friends hold patients. 
    • 7. Persons holding patients must always wear protective apron & gloves if possible. 
    • 8. Use gonadal shielding on all people of child bearing age when such use will not interfere with exam. 
    • 9. Avoid X-raying pregnant patients. 
    • 10. Always collimate to smallest field size appropriate for exam.
  17. Radiation Units
    • Exposure: Roentgen (R) 
    • Absorbed dose: Rad/ Gray (Gy)
    • Dose equivalent: Rem/ Sievert (Sv) 
    • Kerma: Joule/kg Gray (Gy)
  18. Exposure
    • Exposure in air:
    • Roentgen (R): is exposure in air.
    • Columb/Kilogram (C/kg): New term replacing Roentgen.
  19. Absorbed Dose
    • Old term: Rad - Radiation Absorbed Dose
    • New term: Gray (Gy)
  20. Dose Equivalent
    • Occupational exposure
    • Old term: Rem - Radiation Equivalent Man
    • New term: Sievert (Sv)
  21. OSL
    Optically Stimulated Luminescence
  22. Kerma
    • Kinetic Energy Released in Matter
    • Joule/kg Gray (Gy) - absorbed dose. 
    • For diagnostic x-rays, air Kerma is same as abosorbed dose delivered to air that is measured in Grays (Gy).
Card Set
RAD 50