Term
| what is ionizing radiation? |
|
Definition
| radiation that has sufficient energy to produce ions |
|
|
Term
| what does ionizing radiation cause? |
|
Definition
| damage that can be repaired, damage that may be permanent, damage that can cause cell death |
|
|
Term
| what are the 2 types of ionizing radiatinon? |
|
Definition
| man-made, and environmental |
|
|
Term
| what are examples of natural environmental radiation |
|
Definition
| cosmic(sun and stars), earth(uranium, radium, thorium), and radioactive substances(radiopotassium and radiocarbon) |
|
|
Term
| How much radiation do we get from the environment (background radiation) |
|
Definition
|
|
Term
| what are the sources of human-made radiation? |
|
Definition
| nuclear weapons fall out, medical and dental exposures(90%), industrial radioactive materials |
|
|
Term
| what is the erythema dose |
|
Definition
| an old unit of x-ray measurement, measuring the amount of radiation required to turn the skin red |
|
|
Term
|
Definition
| the amount of ionizing radiation that produces ions that carry 1 electrostatic unit of quantity or either positive or negative charge (in 1 cubic centimeter of air) |
|
|
Term
| radiation absorbed dose (rad)(Gy) |
|
Definition
| the amount of radiation absorbed by a medium |
|
|
Term
| rem (dose equivalent)(sievert) |
|
Definition
| measures the biologic affect of ionizing radiation on humans |
|
|
Term
| effective dose equivalent (EDE) |
|
Definition
| the absorbed dose multiplied by the appropriate quality factor and measured in rems) |
|
|
Term
|
Definition
|
|
Term
| EDE limits on students under 18 |
|
Definition
|
|
Term
|
Definition
| .5 rem total and .05 rem per month |
|
|
Term
|
Definition
| the smallest part of an element made up of a nucleus and surrounded by electrons |
|
|
Term
|
Definition
| packets of energy that have the ability to know electrons out of their orbit |
|
|
Term
| when ionization results in a transfer of energy: |
|
Definition
| the x-ray photons can be absorbed, scattered, or pass through without any interaction |
|
|
Term
| what are the 3 main types of photon interactions? |
|
Definition
| photoelectric effect, compton scatter, pair production |
|
|
Term
| what is photoelectric effect? |
|
Definition
| photon knock an inner orbiting electron out and transfers all it's energy to that electron (usually occurs with low energy photons) |
|
|
Term
|
Definition
| deflects off an orbiting electron (the compton electron) shooting off in a different direction with lower energy (called a scatter photon) |
|
|
Term
|
Definition
| a photon with extremely high energy gets close to the nucleus and a positron and electron are formed and once they interact with an orbiting electron they shoot off in different directions (annihilation reaction) |
|
|
Term
| what are the 4 effects that radiation can have on cells |
|
Definition
| pass through, repairable damage, irreparable damage, or cell death |
|
|
Term
| the law of bergonie and tribondeau |
|
Definition
| cells are most sensitive to the effects of ionizing radiation when they are rapidly dividing |
|
|
Term
| what are the most radiosensitive cells |
|
Definition
| lymphocytes along with the eyes, ovaries, and testes (nerve cells are the least sensitive) |
|
|
Term
| what is acute radiation syndrome (ARS) |
|
Definition
| when a larger than 100 R dose is received by the entire body over a short time |
|
|
Term
| what are the 2 categories of long term biologic effect? |
|
Definition
|
|
Term
| what are the 2 categories of long term biologic effect? |
|
Definition
|
|
Term
| what are somatic effects? |
|
Definition
| effect that occur in general body cells and involve all functions (except reproduction) and include cancer, cataracts, and life-span shortening |
|
|
Term
| examples of somatic effects |
|
Definition
| birth defects, mental retardation, childhood leukemia, skeletal and CNS abnormalities, |
|
|
Term
| types of cancer caused by radiation |
|
Definition
| bone sarcomas (watch painters), skin carcinomas (radiologists and techs), and lung cancer (uranium mines workers), cataracts (A-bomb survivors) |
|
|
Term
|
Definition
| occur in the germ cell and are passed down to future generations. |
|
|
Term
| what are the 2 sources of medical radiation exposure |
|
Definition
| x-rays (external), and radionuclides (internal) |
|
|
Term
|
Definition
| a high voltage accelerates the electrons toward a metal target |
|
|
Term
| what does kilovoltage control? |
|
Definition
| the quality of the x-ray beam |
|
|
Term
| what does milliampere control? |
|
Definition
| quantity or the amount of radiation produced |
|
|
Term
| what is primary radiation? |
|
Definition
| the x-rays produced by the tube before it hits any matter |
|
|
Term
| what is secondary radiation? |
|
Definition
| when the primary radiation interacts with matter |
|
|
Term
| what is scatter radiation? |
|
Definition
| harmful to the patient and impairs the diagnostic image |
|
|
Term
| what are radionuclides used for? |
|
Definition
| the treatment of patients with cancer (radiation therapy or oncology) |
|
|
Term
|
Definition
| a human made radionuclide |
|
|
Term
| what is radioactive half-life? |
|
Definition
| the time needed for the disintegration of one half of the atoms of the nuclide |
|
|
Term
| what are good housekeeping practices for internal radiation? |
|
Definition
| not eating, smoking, or food prep/storage in areas where radionuclides are present |
|
|
Term
| what is optimal kilovoltage? |
|
Definition
| As high as possible because it decreases skin dose |
|
|
Term
| what is the inverse square law |
|
Definition
| the intensity of the beam is inversely proportional to the square of the distance |
|
|
Term
| inverse square law correlations |
|
Definition
| when distance is doubled, there is 1/4 the radiation exposure and when the distance is halved, the exposure rate is quadrupled |
|
|
Term
| minimum filtration used in an x-ray tube |
|
Definition
|
|
Term
|
Definition
| limits the area of exposure to the patient |
|
|
Term
| what is the reduction in exposure when gonad shielding is used? |
|
Definition
|
|
Term
| how much lead should be present in shielding devices? |
|
Definition
| .25 mm of lead (.5 mm is suggested for flouro) |
|
|
Term
| 3 types of gonadal shielding |
|
Definition
| shadow shields, flat contact shields, and the shaped contact shield (used by men) |
|
|
Term
| 3 types of gonadal shielding |
|
Definition
| shadow shields, flat contact shields, and the shaped contact shield (used by men) |
|
|
Term
|
Definition
| optically stimulated luminescent dosimeter, worn at the neck to measure dose to the eyes |
|
|
Term
|
Definition
| thermoluminescent dosimetry (highly accurate) |
|
|
