Units of Measure
This SI unit measures radiation exposure in air.
Coulomb/kg
According to the inverse square law, if distance is doubled, intensity is reduced by this factor.
1/4 or decreases by a factor of 4
The X-ray was discovered by this scientist in 1895.
Wilhelm Roentgen
The majority of diagnostic X-rays are produced by this interaction inside the tube.
Bremsstrahlung
This component houses the filament and produces electrons.
The cathode
This SI unit is used to measure absorbed dose in tissue.
Gray (Gy)
If the original technique is 80 kVp at 20 mAs, what should the new mAs be if kVp is increased by 15%?
10 mAs
What is the purpose of filtration in an X-ray tube?
Remove low-energy photons
This interaction occurs when an incoming X-ray photon completely disappears, transferring energy to an electron.
Photoelectric effect
What is the material used for the rotating anode target?
Tungsten
This SI unit accounts for radiation type and tissue sensitivity in dose measurement.
Sievert (Sv)
Calculate the heat units (HU) produced by an exposure using 80 kVp, 200 mA, 0.5 sec on a three-phase generator.
11,200 HU
Name the three cardinal principles of radiation protection.
Time, distance, and shielding
This scatter interaction results in a change in photon direction with reduced energy.
Compton scattering
The line-focus principle describes the relationship between these two focal spots.
The actual and effective focal spots
This unit measures radioactivity and represents one decay per second.
Becquerel (Bq)
If the intensity of an X-ray beam is 400 mR at 40 inches, what will it be at 80 inches?
100 mR
At diagnostic energy levels, which interaction is responsible for image contrast?
Photoelectric effect
What is the purpose of the anode heel effect?
Create intensity variation across the X-ray beam
Using the 15% rule, if an exposure is made at 90 kVp, what would the new kVp be to double the exposure?
103.5 kVp
Coherent scatter occurs at this energy range.
Below 10 keV
Name the two interactions that generate X-rays inside the tube.
Bremsstrahlung and Characteristic