A satisfactory radiograph is made using 100 mA,0.2 sec,80 kVp,and 40-inch SID. How much exposure time is required to produce a similar radiograph when using 400 mA?

Question

Quizplus · Accepted Answer

To maintain the same radiographic density when increasing the mA, the exposure time must be decreased. The original mA-time product is 100 mA * 0.2 sec = 20 mAs. To achieve the same mAs with 400 mA, the time should be reduced to 20 mAs / 400 mA = 0.05 sec.

A Satisfactory Radiograph Is Made Using 100 MA,0