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RT 140 Ch.3
Radiation Protection
Question | Answer |
---|---|
Radiodermatitis | Reddening of the skin |
Aplastic Anemia | Bone Marrow does not produce sufficient new cells to replenish blood cells |
Pancytopenia | Depressed WBC, RBC,& platelet count |
Leukemia | *Hematological malignacies *Types of cancer that affect blood, bone marrow, & lymph node |
Radiation Protection | Effective measures employed by radiation worker's to safeguard patients, personnel, and the general public from unnecessary exposure to ionizing radiation |
Effective Measures | Consist of Both Human and Environmental, Technical and Procedural |
Biological Effects | Damage to living tissue from ionizing radiation |
Tolerance levels | Biological effects were believed to be preventable if radiation dose was limited |
Short term - Somatic Effects | *Acute or Early Effects *Occurred shortly after radiation exposure |
Tolerance Dose | *Radiation dose to which occupationally exposed individual could be continuously subjected without apparent harmful effects *Erythema |
Threshold Dose | Dose of radiation below which an individual has negligible chance of sustaining specific biologic damage |
Effective Dose (EfD) | Dose taking into account dose for all types of ionizing radiation absorbed by organs or tissues Wt |
Roentgen | *Internationally accepted as unit of Exposure to x and gamma radiations *1R= 2.58 x 10^-4 C/kg in air |
Restrictions to Roentgen | * Only X-ray & Gamma rays * Energy below 3 MeV * Only in air |
Bragg Gray Cavity Theory | Relates ionization produced in a gas filled cavity to energy absorbed in surrounding medium |
F-factor | *Roentgen –to rad conversion factor *Dair= 0.876 rad/R x Exposure in Roentgen |
Exposure | *Radiation ionization in air. *Amount of ionizing radiation energy transferred to material medium |
Absorbed Dose | Energy deposited per unit mass by ionizing radiation in biological tissue. |
Equivalent Dose | *Accounts for variation in biologic harm produced by different types of radiation. *Used for radiation protection purpose |
Effective Dose | Quantity attempting to summarize the overall potential for biologic damage from ionizing radiation exposure. |
Ampere | *Is unit of electric current *Traditional unit |
Absorbed Dose | Defined as the amount of energy absorbed per unit mass of irradiated material or biological medium |
Effective Dose | The sum of weighted equivalent doses for all tissues and organs irradiated |
Collective Effective Dose | *Describe Internal and External dose measurements *Describe radiation exposure to population *Low dose of different types of Ionizing Radiation *ColEfD = Effective Dose Avg x No. People Exposed (person-sievert or man-rem) |
Linear Energy Transfer (LET) | The amount of energy transferred on average by incident radiation to an object & is expressed in units of kev/um |
Stochastic effects Nonthreshold | Randomly occurring biologic effects of ionizing radiation such as cancer & genetic abnormalities. |
Tissue Weighting Factor (Wt) | Weighting factor that takes into account the relative detriment to each organ & tissue. |