What technical adjustment is needed to decrease receptor exposure while using AEC?

Decreasing the receptor exposure while using Automatic Exposure Control (AEC) can be effectively achieved by adjusting the density setting on the AEC device. The density setting allows radiologic technologists to fine-tune the amount of exposure that the image receptor receives. By decreasing the density setting, the AEC will terminate exposure sooner than it would at a standard or higher density setting, thus reducing the total radiation dose and resulting in lower receptor exposure.

This approach is particularly useful when the initial images are overexposed due to several factors, such as increased subject density or improper technique settings. Adjusting the density setting does not require major changes to the machine's technical parameters like mA or kVp, making it a straightforward adjustment.

In contrast, increasing milliamperage or decreasing kilovoltage peak would actually lead to increased exposure, not decreased exposure, because both these parameters enhance the amount of radiation reaching the receptor. Similarly, increasing the back-up timer does not directly reduce receptor exposure; rather, it extends the exposure time, which could increase the exposure if the AEC does not terminate at the specified time. Therefore, adjusting the density setting is the most effective and practical solution for controlling receptor exposure in this context.