Which scanning procedure involves measurement of the patient's actual exposure to radiation?

The automatic exposure control (AEC) procedure is designed to measure and regulate a patient's actual exposure to radiation during imaging procedures. This technology adjusts the amount of radiation based on the patient’s body characteristics and the area being imaged, ensuring that the minimum necessary radiation dose is used while still achieving high-quality images. This is crucial in maintaining patient safety and minimizing unnecessary radiation exposure.

In contrast, while procedures such as DEXA scanning, forearm scanning, and spine scanning involve imaging techniques that may use radiation, they do not specifically measure or control the exposure level during the scan. Instead, these techniques typically operate within predefined parameters and set doses that are determined by the equipment settings or manufacturer guidelines, without real-time adjustment or measurement of the actual exposure the patient receives. Thus, AEC stands out as the correct answer because it explicitly focuses on the measurement of radiation exposure.