ARRT Radiography Exam (Mosby Review) Test Questions with Answers

Ionizing Radiation - radiation that is able to remove electrons from an atom through ionization Somatic effects - refers to the effects of radiation to the body being irradiated Genetic Effects - refers to effects of radiation to a germ cell's genetic code; effects the next generation Primary radiation - radiation exiting the x-ray tube Remnant radiation (or Exit Radiation) - x-rays the leave the patient and strike the image receptor attenuation - absorption and scatter of the x-ray beam as it passes through the patient heterogenous beam - x-ray beam that has photons of many different energies photoelectric effect - absorption of x-ray photons in the body compton effect - scatter of x-ray photons in the body air kerma - unit of exposure gray - unit of absorbed dose gray(a) - unit of radiation absorbed in air gray(t) - unit of radiation absorbed in tissue sievert - unit of effective dose or unit of equivalent dose becquerel - unit of activity uncontrolled area - general public area, like waiting room or stairways controlled area - occupied by people trained in radiation safety and wear radiation badges/monitors x-ray tube leakage may not exceed what? - 1mGy(a) per hour at a distance of 1 meter from the housing minimum lead equivalent for fluoro curtain - 0.25mm minimum lead equivalent for bucky slot shield - 0.25mm NAS or NRC-BEIR - National Academy of Sciences/National Research Counsel on the Biological Effects of Ionizing Radiation studies biologic effects of ionizing radiation and publishes the data NCRP - National Counsel on Radiation Protection publishes radiation protection guidelines for the US NRC - Nuclear Regulatory Commission enforces radiation protection standards at the federal level NCRP Report #102 - makes recommendations on equipment design and protection regarding lead shielding and fluoro and mobile exposure rates NCRP Report #116 - makes recommendations pertaining to risk-benefit analysis of radiation exposure; states genetic and somatic effects need to be kept to a minimum; makes annual dose limits NCRP #160 - addresses radiation exposure from all sources to people in the US effective dose limit - upper boundary dose that can be absorbed (either in a single exposure or annually) with negligible risk of genetic or somatic effects to the individual cumulative effective dose - lifetime occupational exposure must not exceed radiographer's age x 10 mSv equivalent dose - equal to the absorbed dose multiplied by the radiation weighting factor equivalent dose limit - upper boundary dose that can be absorbed (either in a single exposure or annually) with negligible risk of deterministic effect Dose Area Product (DAP) - total air kerma striking the patient probabilistic effects (stochastic) - randomly occurring effects of radiation; probability is proportional to the dose (increased dose = increased probability) Deterministic Effects - radiation effects that become more severe at higher levels of radiation exposure; do not occur below a certain threshold