Carlton: IR Exposure "Green Box"

kilovoltage

Directly proportional ↑kVp = ↑exposure ↓kVp = ↓exposure Kilovoltage (kVp) alters the intensity of the beam reaching the IR in two ways. Kilovoltage controls the energy and therefore the strength of the electrons striking the target of the x-ray tube for any given mAs. More important, kilovoltage controls the average energy of the x-ray photons produced at the anode target. Therefore, a change in kilovoltage alters the intensity of the beam when the mAs and other factors remain the same. Kilovoltage also affects the production of scatter radiation. Because of this, a change in kilovoltage alters the intensity of the beam after it enters the subject (or object) but before it reaches the IR.

Additive/destructive pathological conditions

Inversely proportional ↑additive = ↓exposure ↓destructive = ↑exposure

beam restriction/collimation

Inversely proportional ↑collimation = ↓exposure ↓collimation = ↑exposure

distance

Inversely proportional ↑distance = ↓exposure ↓distance = ↑exposure

filtration

Inversely proportional ↑filtration = ↓exposure ↓filtration = ↑exposure

grid ratio

Inversely proportional ↑grid ratio = ↓exposure ↓grid ratio = ↑exposure

anatomical part thickness or tissue type

Inversely proportional ↑thickness = ↓exposure ↓thickness = ↑exposure

milliamperage-seconds

Primary Influencing Factor: Directly proportional ↑mAs = ↑exposure ↓mAs = ↓exposure mAs increases quantity of particles released by the tube.

Using radiolucent/radiopaque contrast media

↑radiolucent = ↑exposure ↓radiopaque = ↓exposure