V1 - Safety Flashcards
A Bremsstrahlung interaction is best described by which statement?
An electron is slowed and changes direction
When the frequency of the voltage waveform supplied to the x-ray tube is increased, what aspect is reduced? (3 answers)
- Patient exposure.
- Heat loading on the anode disk.
- Average wavelength of the x-ray beam.
Which feature of the fluoroscopic equipment is designed to reduce entrance skin exposure to the patient?
Beam Filtration
What is the dose-response relationship of radiation-induced skin cancer?
Threshold
Which term refers to the radiation that exits the x-ray tube through the collimator?
Primary
A portable knee exam performed in the operating room results in beam intensity of 2.5 mgy at 32 inches. What is the intensity of the beam if the same exposure factors are used for a post-op knee at a distance of 40 inches?
1.60 mgy
For which long term effect is a 28-year-old radiographer with a cumulative effective dose (CumEfD) of 200 mSv (20 rem) at an increased risk?
Cancer
What is the term for a reduction in x-ray photon intensity as it passes through the patient?
Attenuation
If a radiographer recieves an exposure of 0.05 msv at a distance of 1.5 feet from the tube of a portable x-ray unit, what will the exposure be at a distance of 6 feet from the tube?
0.003 msv
What is the impact of using 2.5 mm of al/eq filtration on the primary x-ray beam?
Reduction of the patient’s skin dose
The Z number of oxygen is 8. The elemental oxygen atom has two electron shells. How many electrons occupy an electrically neutral oxygen atom’s outer shell?
6
Which protective feature is designed to reduce exposure to the patient during fluoroscopic procedures?
Foot switch
As a result of imaging pregnant patient’s, which is the fetal exposure for most radiographic exams?
Less than 0.01 gray (1 rad)
Which accurately describes the radiation dose absorbed by bone marrow?
The dose will be less than the entrance skin exposure
In an x-ray tube, what is the source of electrons used to make x-rays?
Filament
Which process describes the electron-target interaction in which most diagnostic x-rays are produced?
The filament electron misses all of the orbital electrons and interacts with the target atom nucleus
Which input intensifier screen provides the best radiation protection to the patient during fluoroscopy?
25 cm
The annual effective dose equivalent limit for infrequent exposures recommended by the National Council on Radiation Protection (NCRP) for a member of the general public is equal to how many msv?
5
What causes the build-up of heat at the anode?
Electrons colliding with the target
How much can exposure to the lens of the eyes be reduced by utilizing the PA projection of the cranium over the AP projection?
95%
The majority of x-rays in the useful beam are created as a result of which process?
Fast-moving electrons approach the nucleus of the target atom and slow down.