A radiograph is acquired using an automatic exposure control unit with an exposure setting of 200 mA and 100 kVp. If the initial receptor exposure is measured as 50 microgray, increasing the technique to 300 mA will result in a receptor exposure of which value?

A radiograph is acquired using an automatic exposure control unit with an exposure setting of 200 mA and 100 kVp. If the initial receptor exposure is measured as 50 microgray, increasing the technique to 300 mA will result in a receptor exposure of which value?

• A. 12.5 Gy
• B. 25 Gy
• C. 100 Gy
• D. 50 Gy

Answer: (D)

Automatic exposure control keeps the amount of radiation reaching the receptor essentially constant. When you increase the mA from 200 to 300, the system automatically shortens the exposure time so that the total exposure to the receptor stays the same. In other words, the mAs delivered to the receptor remains the same, so the receptor exposure does not change from the initial 50 microgray. The correct choice is the one that reflects no change in receptor exposure, even though the numbers are presented in different units. This demonstrates how AEC maintains consistent image receptor dose despite changes in technique settings.

Automatic exposure control keeps the amount of radiation reaching the receptor essentially constant. When you increase the mA from 200 to 300, the system automatically shortens the exposure time so that the total exposure to the receptor stays the same. In other words, the mAs delivered to the receptor remains the same, so the receptor exposure does not change from the initial 50 microgray. The correct choice is the one that reflects no change in receptor exposure, even though the numbers are presented in different units. This demonstrates how AEC maintains consistent image receptor dose despite changes in technique settings.