Optimizing the exposure indicator as a dose management strategy in computed radiography

Purpose To investigate a technique for optimizing radiation dose and image quality for a computed radiography system. Methods Entrance skin doses were measured for phantom models of the pelvis and lumbar spine imaged using the vendor's recommended exposure settings (ie, the reference doses) as well as doses above and below the vendor's recommended settings for both body parts. Images were assessed using visual grading analysis (VGA). Results The phantom dosimetry results revealed strong positive linear relationships between dose and milliampere seconds (mAs), mAs and inverse exposure indicator (EI), and dose and inverse EI for both body parts. The VGA showed that optimized values of 16 mAs/EI = 136 for the anteroposterior (AP) pelvis and 32 mAs/EI ? 139 for the AP lumbar spine did not compromise image quality. Discussion Selecting optimized mAs reduced dose by 36% compared with the vendor's recommended mAs (dose) values. Conclusion Optimizing the mAs and associated EIs can be an effective dose management strategy.