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Unit 4 Flashcards
| Question | Answer |
|---|---|
| What is the distance between two consecutive wave crests? | Wavelength (pg. 229) |
| Approximately 79% of manmade radiation exposure in the United States is made from _____________ and ____________. | X-rays and nuclear medicine (pg.231) |
| List four sources of natural background radiation. | Radon and thoron gases, space radiation, internal sources, and terrestrial sources (pg. 231) |
| What is the source of electrons in diagnostic x-ray? | Heated cathode filament (pg. 232) |
| This type of radiation creates about 70-90% of the primary x-ray beam. | Bremsstrahlung (pg. 232) |
| What type of radiation does a relatively low-energy x-ray photon interact with tissue and expends all of its energy to eject an inner shell electron? | Photoelectric (pg. 233) |
| What illustrates the relationship between exposure to ionizing radiation and possible resultant biologic responses? | Dose-response curves (pg. 234) |
| How much radiation does an average chest x-ray emit? | .10 mSv or (10 mrem) (pg. 235) |
| What describes that their is no safe dose and even one photon can cause a response? | Nonthreshold (pg.236) |
| Chromosome aberrations are more likely to occur at ___________ temperatures because repair processes are inhibited. | Lower (pg. 241) |
| How much radiation can result in embryonic resorption or spontaneous abortion during the first 2 weeks of gestation? | At least 250 mGy/25 rad (pg. 242) |
| What sex receives more gonadal radiation exposure? | Females (pg. 243) |
| What is the term when a high dose of radiation delivered to the whole body in a short period of time? | Somatic (pg. 245) |
| What are the four stages of acute radiation syndrome? | Prodromal, Latent, Manifest illness, and recovery or death (pg. 246) |
| What dose leads to Cardiovascular Syndrome where there is a collapse of circulatory system, as increased pressure in the cranial vault, vasculitis, meningitis, ataxia, and shock? | 5000 rad (50 Gy) (pg. 246) |
| What percent of cancers could result from diagnostic radiation? | 5% (pg. 253) |
| What happens when beam is restricted? | Reduces patient dose, reduces production of scattered radiation, and improves image quality (pg. 254) |
| What percent does the NCRP state a single side for SID should be? | 3% (pg.256) |
| Beam filtration results in an x-ray beam to have what? | Higher average energy (pg. 257) |
| What is the purpose of filtration? | To reduce patient skin dose (pg. 257) |
| What is the Aluminum equivalent necessary for equipment operated above 70 kV? | 2.5 mm (pg. 258) |
| List the three items when gonadal shielding should be used? | The gonads lie in, or within 5 cm of the collimated field, the patient has reasonable reproductive potential, and if diagnostic objectives permit (pg. 259) |
| When should breast shields be used? | Female patients during scoliosis series (pg. 261) |
| Ionization chambers and phototimers are two types of what? | Automatic Exposure Controls (pg. 264) |
| Rare earth phosphors are at least ______________ times faster than the earlier calcium tungstate phosphors? | Four (pg. 265) |
| When are 16:1 grid ratio recommended for use? | Examinations using 100 kV (pg. 265) |
| This refers to consistency in exposure output during repeated exposures at a particular setting? | Reproducibility (pg. 266) |
| What is the SSD must be ________ for stationary fluoroscopic equipment? | 15 inches (pg. 267) |
| The quality assurance term used to describe consistency in exposure at adjacent mA station is? | Linearity (pg. 270) |
| What is the limit for occupational dose for technologist for 1 year? | 100 mrem/yr (1mSv/yr) (pg.273) |
| What is the tabletop intensity limit for a fluoroscopic beam? | 10 R/min (pg. 275) |
| What is the most important cardinal rule? | Distance (pg. 277) |
| What is the thickness that lead aprons and secondary radiation barriers must be? | .25 mm Pb (pg. 278) |
| How often should lead aprons and gloves be imaged? | Annually (pg. 279) |
| What mA do most fluoroscopy image-intensified units operate between? | 1 and 3 mA (pg. 281) |
| A pregnant radiographer should wear a special second radiation monitor at waist level _______________ her lead apron? | Under (pg. 281) |
| How high do primary radiation barriers must be? | 7 feet (pg. 283) |
| What is the length the exposure cord must be on a mobile unit? | 6 feet from the x-ray tube and patient (pg. 281) |
| What is the SI unit for rem? | Sievert (Sv) (pg. 288) |
| What describes the radiation absorbed dose? | Rad/ Gray (pg. 288) |
| What measures ionization in air? | Roentgen/ Air Kerma (pg. 288) |
| List the four used personal radiation monitors. | Optically stimulated luminescence, thermoluminescent dosimeter, film badge, and pocket dosimeter (pg. 289) |
| What is the minimum dose OSL dosimeter can read out? | 1 mrem (pg. 290) |
| How long are film badges used for? | 1 month (pg. 291) |
| What does a TLD contain? | Crystalline chips of lithium fluoride (pg. 291) |
| Which dosimeter is more sensitive and precise TLD or film badge? | TLD because it can measure doses as low as 5 mrem compared to film badge (pg.292) |
| When would a pocket dosimeter be used? | When working with high exposures or large quantities of radiation for a short period of time (pg. 292-293) |
| What type of radiation is a radiographer exposed to? | Low-energy, low-LET radiation (pg. 293) |
| What does the NCRP Report No. 116 require occupationally exposed individuals 18 years of age and older not to receive exposures over? | 5 rem (50 mSv) /yr (pg. 294) |
| How do you calculate the lifetime cumulative exposure for the occupationally exposed individual? | 1 rem x age in years (pg. 295) {example 23 year old. 1 rem x 23 = 23 rem (230 mSv) (lifetime at the age) |
| How often are film badges processed? | Monthly (pg. 296) |
| What do OSL, film badges, pocket dosimeters, and TLD measure? | Exposures to x, beta, and gamma radiations (pg. 296, 298) |
| What type of crystals are used in an optically luminescent dosimetry system? | Aluminum Oxide (pg. 298) |
Created by:
bulanowski
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