How CT AEC systems work

• In order to set mA, systems need knowledge of patient attenuation. This comes from:

  • SPR (scout, pilot, topogram or scanogram) views and/or
  • Knowledge of the attenuation from the previous rotation

• To use the system, the operator needs to be able to set the desired exposure level by use of:

  • A ‘standard’ mAs
  • A reference image of the desired image quality
  • A desired image noise level