More and more attention is being focussed on the need to avoid unnecessarily high levels of ionizing radition in digital X-ray imaging. Modern digital imaging
equipment incorporate automatic image brightness correction systems, so monitoring of potential over-exposure depends on the use of equipment safety
features, such as the Exposure Index (EI).
However the accuracy of the EI can itself be affected if the anatomy of the body zone being imaged is not taken into account. To overcome this, a new software system has been developed to calculate a ”true“ EI value. This article describes the general background to the issue of radiation overexposure
and summarizes the principles behind the new software.