A new high frequency radiographic system is being released to a customer for first clinical use.The applications person states that the AEC density controls are in 20% increments.If a normal AEC exposure of the hip is 24 mAs, a repeat exposure at +2 would yield a mAs value of
A)26 mAs.
B)29 mAs.
C)34 mAs.
D)48 mAs.

Question

Quizplus · Accepted Answer

Since the AEC density controls are in 20% increments, each increment would add 20% of the normal exposure of 24 mAs (which is 4.8 mAs). Therefore, a +2 increment would add 2 x 4.8 mAs = 9.6 mAs. Adding this value to the normal exposure would give us a repeat exposure of 24 + 9.6 mAs = 34.6 mAs. However, since the AEC density controls can only adjust in 20% increments, the actual repeat exposure value would be rounded up to the nearest 20% increment. Thus, the final repeat exposure value would be 40% (which is the +2 increment) above the normal exposure value of 24 mAs, rounded up to the nearest whole number increment, giving us a final value of 34 mAs. Therefore, the best choice(s) is C.

A New High Frequency Radiographic System Is Being Released to a Customer