Chapter 4 Radiation Protection Flashcards
Biologic damage to the body of the exposed individual caused by exposure to ionizing radiation
Somatic damage
Reddening of skin due to radiation
Radiodermatitis
The received quantity of radiation that causes diffuse redness over an area of skin after radiation
Skin Erythema Dose
A dose of radiation below which an individual has a negligible chance of sustaining specific biologic damage
Threshold dose
At one time the internationally accepted unit for measurement of exposure to x-radiation and gamma radiation.
-Fluoroscopic entrance exposure
Roentgen
The SI unit of absorbed dose. Energy absorption of 1 joule per kilogram of matter in the irradiated object
Gray
The amount of ionizing radiation that may strike an object, such as the human body, when in the vicinity of a radiation source
Exposure
The basic unit of electrical charge.. Represents the quantity of electrical charge flowing past a point in a circuit in 1 second when an electrical charge of 1 ampre is used
Coulomb
Another SI unit quantity that can be used to express radiation concentration transferred to a point which may be at the surface of a patients or radiographers body—The space in between
Air Kerma
Deposition of energy per unit mass in the patient’s body tissue from exposure to ionizing radiation
Absorbed dose
Quantity that is important for radiation protection purposes, it begins with EqD and then by incorporating, modifying, or weighting factors, which correspond to the relative degrees of radio sensitivity of various organs and tissues.. Quantity that summarizes the potential for biologic damage to a human from exposure from ionizing radiation
Effective Dose
An energy equivalent to transfer of 100 ergs per gram of irradiated dose. Stands for radiation absorbed dose. Used to indicate the amount of radiant energy transferred to an irradiated object by any type of ionizing radiation
Rad (indications)
An adjustment multiplier that was used in the calculation of dose equivalent to specify the ability of a dose or any kind of ionizing radiation to cause biologic damage
Quality factor
The amount of energy transferred on average by incident radiation to an object per unit of length of track through the object and is expressed in units of KeV/micrometer
Linear Energy Transfer
Radiation Quantity used for radiation purposes when person receives exposure from various types of ionizing radiation… Also takes in account the potential variation in biologic harm that is produced by different kinds of radiation
equivalent dose
Nonthreshold randomly occurring biologic effects of ionizing radiation such as cancer and genetic abnormalities
Stochastic effects
Weighting factor that takes into account the relative harm to each organ and tissue
Tissue Weighting Factor
Determines the overall harm to biologic components and the risk developing a radiation induced cancer, or for the reproductive organs–The risk of genetic damage
Weighting factor
Dosimetric quantity implemented for use in radiation protection to describe internal and external dose measurements.. Describes radiation exposure of a population or group from low dose of different sources of ionizing radiation expressed in person-sievert
Collective effective dose
Know why skin erythema dose is not used today?
The dose that caused skin erythema varied from person to person… This was extremely inaccurate
When do short term somatic effects appear?
Within minutes, hours, days, or weeks after the time if radiation exposure
List short term effects
Nausea, fatigue, diffuse redness of the skin, hair loss, intestinal disorders, fever, blood disorders, and shedding of the outer layer of skin
When do long term effects appear?
They appear months or years after exposure
List the long term effects
Cancer, birth defects, and formation of cataracts
REM stands for?
Radiation Equivalent Man
RAD stands for
Radiation Absorbed Dose
LET stands for?
Linear Energy Transfer
What was REM historically known as?
Roentgen Equivalent Man
What is the unit REM used for?
Radiation Quantity
What is effective dose based on?
Energy deposited in biologic tissue by ionizing radiation
WHat two things does effective dose take into account?
- The type of radiation
- The variable sensitivity of the tissues exposed to radiation
What quantity does effective dose actually measure?
The overall risk arising from the irradiation of biologic tissue and organs
What does effective dose take into consideration?
The exposure to the entire body
Know what replaced REM for radiation protection purposes?
Sievert
KNow which dose is used to indicate the amount of ionizing radiation to a patient during a radiographic exam
Absorbed dose
What happens with radiation with a high LET?
High LET radiation transfers a large amount of energy into a small area and can therefore do more biologic damage than radiation with a low LET
Know the relationship between LET and Quality Factor
High LET=High quality factor
Know what the probability of occurrence depends on with stochastic effects?
Radiation dose, type of radiation, and energy of radiation
How to determine EfD (also know formula)
Absorbed dose (D) multiplied by a radiation weighting factor (WR) to obtain EqD and by a tissue weighting factor (WT) EfD=DxWRxWT
Where the dose to the patient is the highest?
Entrance Skin Dose
Know who benefits from a total effective dose equivalent
nuclear medicine technologist and interventional radiologist
