Question

the primary factor controlling x - ray beam quantity is determined by
mas.
kvp.
distance.
filtration.
12 multiple choice 1 point
in order to increase image receptor (ir) exposure by 40 percent, the radiographer would
change the mas from 15 to 21 mas.
decrease the kvp by 40 percent.
increase the mas by 20 percent.
decrease the distance by 40 percent.

Explanation:

1. For the first question, mAs (milliampere - seconds) is the primary factor controlling the quantity of the x - ray beam. It is directly proportional to the number of x - rays produced. kVp affects beam quality (penetrability), distance follows the inverse - square law and affects intensity, and filtration removes low - energy x - rays and affects beam quality.
2. For the second question, the exposure to the image receptor is directly proportional to mAs. To increase the exposure by 40%, if the original mAs is 15, the new mAs should be \(15\times(1 + 0.4)=21\). Decreasing kVp would decrease exposure, increasing mAs by 20% is not enough, and decreasing distance by 40% would change exposure according to the inverse - square law in a more complex way than a simple 40% increase.

Answer:

1. mAs.
2. change the mAs from 15 to 21 mAs.