Chapter 1 - Intro to Radiation Protection Flashcards
A form of ionizing radiation
X-rays
Is radiation that produces positively and negatively charges particles (ions) when passing through matter
Ionizing Radiation
The production of these ions is the event that may cause injury in normal biologic tissue
ionizing radiation
List some consequences of ionization in human cells
- creation of unstable atoms
- production of free electrons
-production of low energy x-ray photons
-creation of highly reactive free molecules( called free radicals) capable of producing substances poisonous to the cell
-creation of new biologic molecules detrimental to the living cell
-Injury to the cell that may manifest itself as abnormal function or loss of function.
Goals of Radiation Protection
-protect persons from both short term and long term effects of radiation
-Use of knowledge of radiation-induced hazards that have been gained over many years
-employ effective methods to eliminate those hazards
-control radiation produced from an x-ray tube and ensure safety during all medical radiation procedures
-limiting the energy deposited in loving tissue by radiation can reduce the potential for adverse effects
Control of “radiant Energy”
Any radiation exposure that does not enhance the quality of the study
Unnecessary Radiation
Any radiation exposure that does not benefit a person in terms of diagnostic information obtained for the clinical management of medical needs.
Unnecessary Radiation
Effective measures employed by radiation workers to safeguard patients, personnel, and the general public from unnecessary exposure to ionizing radiation
Radiation Protection
-Ongoing responsibility of diagnostic imaging professionals to ensure radiation safety during all medical radiation procedures
-obligation is fulfilled by adhering to an established radiation protection program
Concept of radiation protection
Measured in coulomb per kilogram [C/kg], or milliroentgen [mR]
Exposure Dose
The amount of energy that is deposited in a material per unit mass of the material. measured in milligray [mGy]
Absorbed Dose
Amount of radiation produced in air when ionizing radiation is present. Measured in coulomb per kilogram [C/kg], or milliroentgen [mR]
Exposure Dose
A quantity that is a measure of general harm in humans. Measured in millisievert [mSv]
Effective Dose
protects against leakage radiation and electric shock
Tube housing
Vacuum environment
Tube or glass envelope
-negative electrode
-contains the filament and focusing cup
Cathode
-made of thoriated tungsten
-high melting point
-responsible for producing thermionic emission
-source of electrons for xray production
-determines the size of the focal spot
-may have 2- dual focus tube
Filament
-made of nickel /molybdenum
-keeps the electron cloud/ space charge
Focusing cup
-made of tungsten or tungsten rhenium alloys
-serves as a target for projectile electrons and primary thermal conductor of the tube
-rotating anodes : allow for greater heat capacity
Rotating Anodes
examples of short term
hair loss
redness of skin