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Sherer 7-10
Radiation protection
Question | Answer |
---|---|
Responsibilities of radiation protection organizations: | Evaluate relationship between EqD and biologic effects and formulate risk estimates of somatic and genetic effects |
Responsibilities of Radiation Safety Officer | Develop appropriate radiation safety program |
RSO is usually: | a medical physicist |
Effective Dose Limit | level of radiation effective dose that has been recommended as an upper boundary dose of ionizing radiation that results in a negligible risk of bodily injury or damage. |
Effective Dose limits may be expressed for | whole body exposure, partial body exposure, and exposure of individual organs |
Effective dose limits are designed to minimize the risk to humans in terms of | non stochastic and stochastic effects. |
Effective dose limits do not include | natural background and medical exposure. |
Radiation Control for health and safety act of 1968 was enacted by: | congress to protect the public from unnecessary radiation. (microwave, television, x-ray) |
Code of standards for diagnostic x-ray equipment - 1974 | additional standard requirements such as PBL, minimum filtration, linearity, reproducibility, beam on indicator, and back-up timer |
Consumer-Patient Radiation Health and Safety Act of 1981 | provides federal legislation requiring the establishment of minimal standards for accreditation of education programs for persons who administer radiologic procedures. |
The current radiation protection philosophy is based on the assumption that | a linear, non-threshold relationship exists between radiation dose and biologic response. |
Occupational risk should not exceed risk of | "safe industries"; 2.5% chance of fatal accident over entire career. |
Annual occupational effective dose limit | 5 rem of whole body, not including medical and background radiation |
Cumulative effective dose (CumEfD) limit | 1 rem times age |
Collective effective dose (ColEfD): | population, or group exposure to low doses of different sources of ionizing radiation |
Limit for pregnant female radiation workers: | 05 rem (50 mrem) per month, or .5 rem (500mrem) for entire pregnancy |
Limit for education and training purposes of individuals under 18 years of age: | .1 rem/year (100mrem) |
Negligible individual dose: | 1 mrem/year; an annual effective dose that provides a low-exposure cut-off level so that regulatory agencies may dismiss a level of individual risk as negligible |
Action Limits: | limits to occupational exposure that are set by the medical facility well below the regulatory values as they appear in state or federal regulations |
Dose limit for eye: | 15rem/year |
Dose limit for skin and extremities: | 50rem/year |
Dose for temporary sterility: | 200rem |
Dose for permanent sterility: | 500-600rem |
Depressed sperm count or menstrual irregularity can happen as low as: | 10rem |
First step in patient radiation protection: | Effective communication |
X-ray beam limitation devices are used to: | confine the useful beam and reduce unnecessary exposure and scatter radiation |
Types of beam limitation devices: | aperture diaphragm, cones, collimators (PBL) |
Patient skin should be at least ___ cm below collimator | 15 |
The x-ray field must coincide with the light field of the variable-aperture light-localizing collimator, and must be within ___ of SID | 2% |
The purpose of beam filtration is to reduce exposure to: | patient's skin and superficial tissues |
Filtration elements absorb most of the ____ energy photons from the heterogeneous beam, thereby ______ it's mean energy and ______ patient dose. | low; increasing; reducing |
Two types of filtration: | inherent (.5 mm Al equivalent) and added (2.0 mm Al equivalent) |