CLO04: Analyze the relationships of factors that control and affect image exposure.
Image exposure is controlled by kilovoltage peak (kVp) and milliampere-seconds (mAs). Kilovoltage can alter the penetrating ability of the x-ray beam as well as the amount of penetrability. Milliampere-seconds is directly proportional to the exposure. The anatomy must first be penetrated before mAs can be adjusted. If the kVp is too low then the beam will not penetrate the part and will become scatter radiation. The 15 percent rule can be applied to increase exposure to the image receptor. An amount of 0.15 would be multiplied by the original kVp and then add that total to the original kVp.
Rad Radiography 