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RADT 456: Rad Prot.
ARRT registry review covering radiation protection
Question | Answer |
---|---|
Interaction that contributes significantly to patient dose | photoelectric effect |
interaction that contributes to image fog and pose a radiation hazard to personnel | compton scatter |
cardinal principles of radiation protection | time, distance, and shielding |
dose response curve that is proportional to the radiation dose received only after some particular dose is received | linear threshold |
dose response curve that does not occur with degrees of severity, referred to as stochastic effects, no safe dose | linear nonthreshold |
dose response curve in which the effects of radiation are not proportional to the dose received | nonlinear curve |
usually a result of high dose in short period of time | early somatic effects |
can appear years after exposure: carcinogenesis, cataractogenesis, embryologic effect, lifespan shortening | late somatic effects |
states that the most radiosensitive cells are young, undifferentiated, and highly mitotic cells | Law of Bergonie and Tribondeau |
the sum of the products of the dose equivalent to various irradiated organs or tissues and their applicable weighting factors | effective dose equivalent |
the rate at which radiation deposits energy as it passes through tissue is known as | linear energy transfer (LET) |
the most radiosensitive cell | lymphocyte |
as the LET of radiation increases, the radiation's ability to produce biologic damage also increases -true or false | true |
diagnostic x-rays are considered high LET radiation- true or false | false, low LET radiation |
occurs with high LET radiation and when ionization occurs at the DNA molecule | direct effect |
occurs most frequently, happens when ionization takes place away from the DNA molecule, in cellular water | indirect effect |
the indirect effect is predominant with high or low LET radiation | low |
radiographers must follow _____ as they carry out their tasks | the ALARA principle |
what is the safest time to schedule elective procedures of the abdomen/pelvis for female patients | 10-day rule, the first 10 days following onset of the menses |
the single most important factor in keeping patient dose to a minimum | beam restriction |
removes low-energy x-rays from primary beam, thereby reducing patient skin dose and increasing the average energy of the beam | filtration |
equipment operated above 70 kV must have at least _____ mm Al equivalent | 2.5 |
______ should be used if gonads lie within 5 cm of collimated beam, if patient has reproductive potential, and if diagnostic objectives permit | gonadal shielding |
reproducibility- any variation in output intensity must not exceed | 5% |
linearity- any variation in output intensity must not exceed | 10% |
SSD must not be fewer than ___ inches for all radiographic procedures other than dental radiography | 12 |
the tabletop intensity of the fluoroscopic beam must be fewer than | 10R/min |
most occupational exposure is received in what 2 areas | fluoroscopy and mobile radiography (especially c-arm) |
the rem SI unit of measurement is | Sv (Sievert) |
measures ionization in air and can be referred to as the unit of exposure | roentgen |
contains a thin layer of aluminum oxide | optically stimulated luminescence (OSL) dosimeter |