If 40 mAs are needed to produce an adequate exposure for a given projection using a 200-speed imaging system, how many mAs would be needed if the speed were changed to 800?

Question

Quizplus · Accepted Answer

When the speed of an imaging system increases, the amount of radiation (mAs) required for adequate exposure decreases. The relationship between speed and mAs is inversely proportional. Going from a 200-speed system to an 800-speed system is a 4x increase in speed (800/200 = 4). Therefore, you need 1/4th the original mAs. 40 mAs / 4 = 10 mAs.

If 40 MAs Are Needed to Produce an Adequate Exposure