V3 - Safety Flashcards
What is the primary purpose of beam filtration?
Protect patient from low energy x-rays
Place the following actions in order of greatest to least impact for reducing occupational exposure during fluoro.
Stand behind the control panel > Double distance from x-ray source or patient > Cut exposure time in half > Wear a led apron
A 6yo pediatric patient arrives in radiology suite for a radiograph of the abdomen. Which set of technical factors provides the best radiation protection?
82 kVp, 7.5 mAs
Which is the primary controlling factor for x-ray beam quality?
kVp
Which fluoroscopic mode results in the lowest patient dose?
Digital pulsed progressive
Which are by-products of photoelectric absorption?
Photoelectron and characteristic photon
When a pregnant patient must undergo a radiographic procedure, which practices will minimize radiation exposure? (3)
- Select appropriate exposure factors for the parts being imaged.
- Shield the abdomen and pelvis whenever this does not interfere with the image.
- Collimate to include only the area of interest.
Which statement correctly describes the amount of kinetic energy required for a photon to remove an inner shell electron from its orbit?
The same as or greater than the electron binding energy.
Which term means the loss or change of a nitrogenous base in the DNA chain?
Mutation
Which describes the relationship between linear energy transfer (LET) and relative biologic effectiveness (RBE)?
As LET increases, RBE increases
What is the advantage of using a high kVp, and low mAs technique with DR systems?
Patient exposure decreases
For which purpose is gonadal shielding recommended?
To reduce the probability of genetic mutations
How will the dose area product (DAP) be affected during a 4 Roentgen exposure if the collimated field is reduced from 8 x 8 cm to 4 x 4 cm?
DAP will be 1/4 of the original
Which human cell is the most resistant to the effects of the radiation?
Neurons
At which energy range does photodisintigration occur?
Above 10 megaelectron volts (MeV)
How should a mobile C-arm fluoroscope be positioned to provide maximum radiation protection to the operator?
With the x-ray tube under the patient and as far from the patient as possible
A radiographer performs an abdomen examination with a mobile DR system. In order to reduce the likelihood of repeat exposure, he decides to increase the technical factors slightly more than necessary. Which term refers to this undesirable practice?
Dose creep
Which combination of technical factors is recommended to reduce patient dose?
High kVp, low mAs
According to FDA, what is the maximum air kerma rate for fixed fluoroscopic units?
10 cGy/min
Which regulatory agency has the authority to control the possession, use, and production of atomic energy in the interest of national security?
Nuclear regulatory commission
Which procedures should imaging personnel perform in order to reduce exposure time during fluoroscopic procedures? (3)
- Use the pulsed progressive mode.
- Use the last image hold feature.
- Reset the cumulative timer before procedure.
Which whole-body dose most closely approximates the LD 50/30 for humans?
3 Sv
A radiographer stands 6 feet from the x-ray source when performing a portable chest exam and receives an exposure of 2 mGy. If the radiographer performs a repeat exam using the same technical factors standing at a distance of 3 feet from the course, how much exposure will be received?
8 mGy
Place the following types of dosimeters in proper order from least radiosensitive to most radiosensitive.
Film badge > TLD > OSL > Pocket ionization chamber
