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RAD230 Final
Question | Answer |
---|---|
The doubling dose typically occurs at how many rem? | 156 |
What is the LD 50/60 for humans? | 350-400 rad |
On average, how many rads would cause ARS? | 600 |
Who came up with the 10-25 Rule and what is it? | Bushong; <10 rad = don't abort, 10-25 = could consider abortion, >25 rad = strongly consider abortion |
Stages of ARS? | prodromal, latent, manifest illness, death/recovery |
Stages of Stage III ARS? | hematopoietic, gastrointestinal, cerebrovascular |
Exposure dose for Prodromal stage of ARS? | 50-100 rad |
Exposure dose for Hematologic Syndrome of ARS? | 100-1000 rad |
Exposure dose for Gastrointestinal Syndrome of ARS? | 600-5000 rad |
Exposure dose for Cerebrovascular Syndrome of ARS? | 5000 rad |
Exposure dose for erythema? | 200 rad |
Exposure dose for decreased sperm count/delayed menstruation? | 10 rad |
Exposure dose for temporary sterility? Permanent? | 250 rad;500 rad |
Exposure dose for impotence? | 3000 rad |
Exposure dose for hematologic depression? | 25 rad |
3 types of blood cells? | leukocytes (WBC), erythrocytes (RBC), thrombocytes (platelets) |
Latent period for leukemia? | 5-7 yrs |
Latent period for solid tumors such as thyroid cancer? | 10 yrs |
How many types of leukemia? Which one typically affects children? | 4; Acute Lymphocytic Leukemia |
Most cancers have what type of dose response curve? | linear, non-threshold |
What type of dose response curve is skin cancer? | linear threshold |
What is the mean glandular dose for a mammogram? | 1 mSv |
What part of the heart is most radiosensitive? | epithelial lined cavities such as blood vessels |
Genetic mutations have what type of dose response curve? | linear, non-threshold |
Genetically Significant Dose takes into account _______. | Gonadal dose to a population |
During preimplantation, how much exposure would terminate the pregnancy? | 5-15 rad |
What is the time frame for preimplantation? Organogenesis? | 0-9 days; 10 days-6 weeks |
How much radiation can cause a fetus to develop congenital malformations? Leukemia? | 20-25 rad; 50 rad |
How much filtration is required for <50 kVp? 50-70 kVp? >70 kVp? | 0.5 mm Al; 1.5 mm Al; 2.5 mm Al |
SSD for mobile? Stationary? | 12"; 15" |
How thick should a primary barrier be? Examples? | 1.5 mm (1/16"); walls, floor |
How thick should a secondary barrier be? Examples? | .8 mm (1/32"); ceiling, door, control booth, aprons |
What is Use Factor? | amount of time the beam is on and directed at a barrier |
What is Workload? | volume of exams per week |
What is the sensitivity range of a film badge? | 10 mrem-500 rem |
What is the sensitivity of TLD? What is it similar to? | 5 mrem; skin tissue |
NCRP Report #116 Occupational Dose Limits for whole body? Eyes? Skin? | 5 rem/yr; 15 rem/yr; 50 rem/yr |
Annual whole body dose for the public? Eyes? Skin? | 0.1 rem/yr; 1.5 rem/yr; 5 rem/yr |
Occupational Dose Limits for pregnant employees? | 0.05 rem/month for 10 months =.5 rem |
How do you calculate Cumulative Effective Dose? | age in rem or 10mSv*age |
Lead apron covers how much active bone marrow? | 80% |
Lead apron thickness? | minimum of 0.25 mm Pb, but usually 0.5 mm |
At 75 kVp how much of the beam is attenuated by a lead apron? | 90% |
How long should the cord be on a portable x-ray machine? | 6 feet (2 meters) |
A scattering event reduces exposure by _____. | 1/1000 |
How much is inherent filtration? Added? | 0.5 mm Al; 2 mm Al |
How much scatter does a 5:1 grid remove? 8:1? 12:1? | 82-85%; 90%; 95% |
Gonadal shielding landmark for males? Females? | pubic symphysis; 1" medial to ASIS |
Male shielding reduces gonadal dose by how much? Female? | 90-95%; 50% |
ESE for KUB? | 300 mrem |
ESE for chest x-ray? | 10-15 mrem |
How thick should the fluoro curtain be? | .25 mm Pb |
How thick should the fluoro table be? | 1 mm Al |
What is the maximum fluoro exposure rate? | 10R/minute |
How thick should lead gloves be? | 0.25 mm Pb |
When should a warning sign be posted? | 5mR/hour |
What is the maximum allowed leakage from the tube housing? | 100mR/hour @ 1 meter away |
ESE for AP l-spine? | 350 mrem |
What type of cancer has a latent period of 2 years? | leukemia |
NCRP Report #93 annual radiation dose from background? Manmade? | 295 mrem; 65 mrem |
NCRP Report #160 annual radiation dose from background? Manmade? | 320 mrem; 300 mrem |
What is the sensitivity of OSL? | 1 mrem-1000 rem |
What type of dose response curve is breast cancer? | non-threshold, linear quadratic |
How big should the control booth window be? Where should it be? How thick should it be? | 1 square foot; 5 feet above the floor; 1.5 mm Pb |
How much lead is required for the fluoro image intensifier's housing? | 2 mm |
When using an air gap technique, where should the tube and IR be? | IR is 6-10" from the patient, tube is 10-12' from IR |