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Rad Bio Test 4
Radiation Protection
Question | Answer |
---|---|
Name some US regulatory agencies. | *NRC (Nuclear Regulatory Commission) *EPA (Environmental Protection Agency) *FDA (Food & Drug Administration) *OSHA (Occupational Safety & Health Administration) |
What organization group makes recommendations on occupational & public dose limits based on info from UNSCEAR & NAS/NRC-BEIR? | ICRP- international commission of radiation protection |
What group reviews ICRP, recommends & implements them into a US radiation protection policy? | NCRP- national council on radiation protection |
Which group's main function is to oversee nuclear energy industry, controls manufacture, use & dispose radioactive substances? | NRC- nuclear regulatory commission |
Which group monitors places of employment? | OSHA |
Which group regulates design & manufactures electronic products including xray equipment? | FDA |
Which individual is responsible for maintaining individual radiation records? | RSO- radiation safety officer |
How many mSv is the EfD to the lens of the eye? | 150mSv |
What is the EfD to the skin, hands and skin in mRem? | 50mRem |
What is the traditional unit for EfD to the lens of the eye? | 15 Rem or 15,000 mRem |
What is the EfD in SI units for skin, hands and feet? | 500 mSv |
What is the EfD for annual whole body exposure in traditional units? | 5 Rem or 5,000 mRem |
What is the EfD for cummulative whole body exposure in SI units? | 10 mSv X age |
Where should the second monitor be worn for a pregnant tech? | placed under the lead apron at waist level |
What is the formula when calculating cumulative whole body dose in traditional units? | 1 Rem X age |
What is the EfD limit for embryo/fetus of declared pregnant women for the entire pregnancy? | 0.5 Rem (500 mRem)/ 5mSv |
What is the NCRP recommended dose limit per month for a pregnant tech? | .05 Rem |
What is the notification level for deep tissue exposure for SLCC? | 400 mR |
What is the notification level for shallow exposure for SLCC? | 1000mR |
What are the different types of dosimeters? | *film badge *OSL *TLD *pocket dosimeter |
What measures background exposure that is subtracted from personnel monitors? | Control monitors |
What are the three types of field survey instruments? | *cutie pie *geiger-mueller counter *calibration instruments |
Which field survey instrument is used in xray, gamma, and beta radiation? | Geiger counter |
Which survey instrument is used in nuclear medicine? | Geiger-counter |
Which survey instrument is used to detect leakage radiation? | Cutie pie |
Which survey instrument measures exposure rate and cumulative exposure? | Cutie pie |
Which survey instruments have a ionization chamber? | All of them |
What does DAP stand for? | Dose area product |
What is the term to describe a collection of de-identified patient radiation dose data from individual medical imaging exams? | Radiation dose registry |
What are the three cardinal principles of radiation protection? | Shielding, time, distance |
What does ESE stand for? | entrance skin exposure |
What's the average ESE for an exam? | 3R/min |
A fluoro emits 5R/min. What the pt's exposure for a BAE that is conducted that requires 3.5 min of fluoro time? | 17.5R (5R/min x 3.5 min) |
High dose exposure using high dose mode should not exceed what? | 20R/min |
High dose control exposure using AEC should not exceed what? | 10R/min |
High dose control exposure using manual mode should not exceed what? | 5R/min |
What are some ways to reduce beam intensity for fluoro? | *high kV to minimize mA *when not needed, remove grid *avoid magnification & high dose modes |
Total tube filtration for equipment that uses above 70 kVp should be a minimum of ______mm Al eq. | 2.5 |
Fluoro beam at the IR should not exceed visible image area by more than _____% of SID. | 3% |
"Hardening the beam" is known as _____________. | tube filtration |
Accuracy of PBL should not exceed ____% of SID. | 2% |
What does PBL stand for? | positive beam limitation |
Beam limitation (collimation) reduces what 2 things? | patient exposure & scatter |
If you increase your kVp what happens to mAs & pt. dose? | decrease |
To reduce ESE the minimum SSD should be what for mobile units (answer in cm)? | 30cm (12") |
How long by law should the fluoro timer be set at? | 5 min |
What is the switch called when exposure is only on when pressure is applied to activate; normally operated by the radiologist? | dead man's switch |
Gonad shielding should always be used when the gonads are in or within approx. how many cm of a properly collimated field? | 5cm |
As mm of Pb increases, weight of the lead apron increases what happens to the % of attenuation? | increases |
The II on the fluoro must have a minimum of ____mm of lead. | 2 |
How thick must personal shielding be? | .25mm |
How thick are thyroid shields? | .5mm |
In fluoro, what two things reduce occupational exposure from scatter? | protective drapes and bucky slot cover |
When using the c-arm what can be done to reduce scatter? | position the c-arm so that the xray tube is under the patient whenever possible |
Tube leakage must not exceed ____ mR/hr. | 100 |
In fluoro, what is the primary barrier? | II |
Tube housing provides protection from what kind of radiation? | leakage radiation |
What is the exposure limit for an uncontrolled area? | 2mrem/wk |
What does it mean by occupancy factor? | time that the area adjacent to xray room is occupied |
What are some factors that affect barrier thickness? | *Inverse Square Law *Use Factor *Workload |
What two materials commonly make up the primary protective barrier? | lead & concrete |
What kinds of radiation does the secondary barrier protect individuals from? | scatter and leakage radiation |
How thick must the secondary protective barrier be? | 1/32" |
How thick must the primary protective barrier be? | 1/16" |
Where is the primary protective barrier located in relationship to the xray beam? | perpendicular to the undeflected line of travel of xray beam. |
What are 3 categories of radiation that an individual needs to be shielded from? | *primary radiation *leakage radiation *scatter radiation |