Which exposure factor is controlled by the automatic exposure control (AEC) system?

The automatic exposure control (AEC) system is designed to optimize the duration of exposure in radiographic imaging. Its primary function is to automatically terminate the exposure once the appropriate amount of radiation has reached the image receptor. This is crucial in ensuring that the resulting images have the correct density and contrast, tailored to the specific imaging requirements for varying body types and conditions.

In this context, AEC primarily interacts with the time factor, which directly influences how long the detector is exposed to radiation. By controlling the time of exposure, the AEC helps maintain consistent image quality while reducing the risk of overexposure or underexposure to the patient.

In contrast, factors such as kilovoltage peak (kVp), milliamperage (mA), and source-to-image distance (SID) are typically set manually by the radiologic technologist prior to the examination based on the imaging technique and patient factors. While kVp affects the quality of the x-ray beam and mA influences the quantity, neither is automatically adjusted by AEC during the exposure process. Similarly, SID is a fixed distance determined by the positioning of the x-ray tube and the film or receptor, and is not managed dynamically by AEC.

Therefore, understanding that AEC primarily controls