Automatic exposure control (AEC) optimizes the radiation dose that a patient receives based upon their size and the different densities of the tissues being imaged. The dose is optimized so that the minimum dose necessary to obtain quality images is utilized.
AEC can adjust the mA and kV in the x, y, and z-axis of the patient in real-time. The mA is adjusted based upon the density of the object that is being imaged during that specific moment of the acquisition.
The proper mA and kV is calculated from the scout images that obtained prior to the acquisition. The denser the object being imaged is, the higher the calculated dose.
It is crucial that artifacts and objects be removed from the patient, if possible, prior to the acquisition of scout images. Any artifact in the scout image will be used in the calculation of the exam’s technical parameters.
Each CT scanner has a preset range of mA and kV that are acceptable to use when optimizing the patient’s radiation dose. This ensures that optimal image quality is consistently obtained.