Karin Topfer

Optimized Operation and Offset Corrections for a Battery-Powered, Wireless Digital X-Ray Detector

It has been widely recognized that gain and offset corrections are essential for obtaining diagnostic image quality from flat-panel digital X-ray detectors. While such corrections are straightforward for detectors that are always powered and operate in a steady state, a new generation of battery-powered wireless detectors poses new challenges. Factors that need to be taken into account when optimizing the operation of such devices include image quality, battery life, robustness with respect to environmental variables and use patterns, and workflow, e.g., the readiness of the detector upon operator interaction, exposure lag, and image access time. Examples are given of the resolution to these problems for a new portable 35 × 43 cm2 X-ray detector. Multiple power states are required to extend battery life, including a low power state that simply supports wireless communication while the detector is not taking images. As a consequence, the detector encounters slightly different operating conditions during the X-ray exposure compared with the dark images that are taken for offset compensation. A new offset-correction algorithm was developed to compensate for such systematic differences, and its performance was evaluated in terms of image uniformity and noise.