August 2014 Flashcards
Which of the following does NOT protect the patient by limiting the volume of tissue being exposed?
A. Collimator
B. Cylinder cone
C. Aperture diaphragm
D. Filter
Filter
The formula rad x QF is used to calculate the:
Rem
What term refers to the radiation that is produced when an electron moves from an outer shell to fill a vacancy in an inner shell?
Characteristic radiation
Occupational radiation monitoring is required when it is likely that an individual will receive ______ in any single year.
.5 rem
Which of the following may result in reduced radiation dose to the patient?
- AEC
- Slow film/screen speed
- Lowest mAs possible
All
Secondary barriers are not designed to protect people from:
The primary beam
Which of the following would allow an individual to survive larger amounts of radiation?
A. Protraction
B. Fractionation
C. Both A & B
D. None of the above
Protraction and Fractionation
What happens when a state is considered to be an “agreement state” with the NRC?
Radiation protection regulations are enforced by state
Attenuation of a diagnostic x-ray beam is the result of which of the following?
- Photoelectric effect
- Compton effect
- Pair production
Photoelectric and Compton
Which of the following radiation induced effects would require a threshold dose?
A. Acute radiation syndrome
B. Radiation induced leukemia
C. Genetic effects of radiation
D. None of the above
Acute radiation syndrome
Which of the following would result in the greatest increase in patient exposure?
A. Use of 100 speed screens instead of 200 speed screens
B. Adjusting collimation from a 10x12 field to an 8x10 field
C. Increasing the kVp and decreasing the mAs to maintain exposure to the IR
D. Utilizing an 8:1 grid instead of a non-grid technique
Utilizing an 8:1 grid instead of a non-grid technique
The protective curtain on the fluoroscope between the patient and the radiographer protects:
The radiographer from scatter radiation
Patient dose will increase during cine fluoroscopy with a ____.
Smaller field of view and an increased number of frames per second
Which of the following devices is not considered a personnel monitoring device?
A. Geiger-Müller counter
B. Optically stimulated luminescent dosimeter
C. Pocket dosimeter
D. Thermoluminescent dosimeter
Geiger-Müller counter
What is the most effective way to reduce the dose to a radiographer in the exam room during a fluoroscopic exam?
Doubling distance from fluoroscopic table
Which photon-tissue interactions results in the production of a recoil electron?
Compton’s interaction
Which of the following would have the longest wavelength?
A. Gamma radiation
B. Diagnostic x-rays
C. Cosmic radiation
D. Visible light
Visible light
Thyroid shields worn during fluoroscopic procedures should be ____ lead one lead equivalent.
.5 mm
Effective dose is partially based on:
The radiosensitivity of various tissues and organs
How frequently should the lead aprons be checked for holes and cracks?
Annually
The detector array ______ in a cassette-less digital system.
Converts remnant x-rays to an electronic signal
What supplies free electrons for x-ray production?
Thermionic emission
The ______ operates on the principle of self-induction .
Autotransformer
The amount of current needed to heat the filament in an X-ray tube is:
3-5 amps
This type of system does NOT require analog to digital conversion.
Film/screen
The image on the output phosphor of an image intensifier is:
- Brighter than the input phosphor
- Dimmer than the input phosphor
- Larger than the input phosphor
Brighter than the input phosphor
With an AEC device:
A backup timer is required
300 mA 400 mA
.01 second ____mA
200 film/screen speed 100 film/screen speed
80 kVp 70kvp
.03 second
400 mA _____ mA
1/5 second 1/10 second
60 kVp 70 kVp
8:1 grid 5:1 grid
200 mA
50 mA 300mA
.30 second _____ second
100 film/screen speed 200 film/screen speed
5:1 grid 8:1 grid
.05 second