Technological developments of X-ray computed tomography over half a century: User’s influence on protocol optimization

•Technological developments in CT have led to an increased number of processes for protocol optimization.•Many acquisition and reconstruction parameters are interrelated, making them more complicated to adjust individually.•Adjusting CT parameters is as slotted dials: An adjustment will have an influence on image quality and radiation dose due to their interrelation.•Within the optimization process, the user's influence has increased, while automated tools were integrated to assist in optimization.•Technological improvements combined with attention to the human side by the radiographer will lead to the optimal scanning procedure.