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Radt: 456
Radiation Protection
Question | Answer |
---|---|
Addresses relative tissue sensitivity and states that stem cells, immature tissues, and miotic cells are radiosensitive. | Law of Bergonie and Tribondeau |
The effects of radiation are not proportional to the dose receieved | Nonlinear curves |
Appears a short time after exposure | Early effects |
Responses that are proportional to the radiation dose received | Linear curve |
Carcinogensis, cataractogensis, embryologic effect, lifespan shortening. | Late effects |
Ionization takes place away from the DNA molecule | Indirect effect |
High LET at the DNA molecule | Direct effect |
The rate at which radiation deposits energy as it passes through tissue is | Linear energy transfer |
Two devices that help reduce patient dose | Collimator and gonad shield |
Irradiation of water molecules within the body and their resulting breakdown | radiolysis |
Where does most of the populations radiation come from? | Background radiation |
________ determines the penetrability of the x-ray beam. | kV |
________ is used to control the quantity of ionizing radiation delivered to the patient. | mAs |
List 3 types of lead shields | Contact, Breast, Shadow |
Low ___ and high ____ factors help keep patient dose to a minimum. | mAs, kV |
Used to automatically regulate the amount of ionizing radiation delivered to the patient and image recorder | Automatic Exposure Control (AEC) |
____ function to remove a large percentage of scattered radiation. | Grids |
ALARA | as low as resonably achievable |
Principal guidelines for reducing radiographic exposure | time, distance, shielding |
Fluroscopic equipment must provide at least ___ inches between x-ray source and patient. | 12 |
Absorbed dose is measured in | rad |
rad SI unit | Gy |
Occupational exposure | rem |
rem SI unit | Sv |
As the atomic number of the irradiated tissue increases, a ________ number of x-ray photons are absorbed by the tissue. | greater |