Science to practice automatic exposure control in CT: Are we done yet?

It is clear that there is great potential for further dose reduction in CT. It is time to move this science into practice, as did Nakayama et al (7) in a companion article published in the same issue of Radiology. The authors performed abdominal CT in 40 patients at 120 kV, with follow-up scanning performed at 90 kV. Although they did not increase the tube current-time product at the lower tube voltage setting, overall image quality and enhancement of abdominal organs were not significantly different between the examinations performed at 120 kV and at 90 kV (P > .5). What was different was dose, with a weighted CT dose index reduction of 56.8% at the lower tube voltage. Clearly, the radiology community is not done with dose reduction in CT until radiologists adopt the principles of scanning with low tube voltage for small patients into clinical practice.