Room: Room 207
Purpose: To evaluate the image quality of both dual-energy (DE) tissue-subtracted and digital radiography (DR) images obtained with a novel single-shot, triple-layer flat-panel detector and compare its performance with a dual-shot kVp switching system and a single-shot dual-layer flat panel detector with a copper mid-filter.
Methods: A tissue-mimicking non-anatomical phantom was constructed using aluminum as a bone substitute and acrylic as a soft-tissue substitute. Two step wedges were built out of these materials (in 1mm steps ranging from 0 to 4mm for aluminum, and 0.5â€™â€™ steps ranging from 1 to 3â€™â€™ for acrylic) and placed perpendicularly to evaluate the material-subtracting capabilities of each detector under increasing amounts of opposite material type. The phantom was imaged using the three DE techniques: a dual-shot system; a single shot dual-layer flat-panel detector with a 1mm copper mid-filter and the novel single shot triple-layer detector. The resulting material-subtracted images were compared by measuring signal difference to noise ratio per root entrance exposure (SDNRpX) at each of the phantomâ€™s steps. Since these imaging systems are also capable of simultaneously generating DR images, their quality was evaluated using detective quantum efficiency (DQE).
Results: SDNRpX results show that all three techniques produce comparable DE images. However, DQE measurements show significantly reduced quality of DR images for the dual-layer detector while the other two techniques produce comparable results to conventional DR.
Conclusion: The comparable quality of DE and DR images taken with the single-shot triple-layer detector and the dual-shot technique, together with the advantages of the triple-layer approach (i.e. real-time operation, portability, absence of motion artifacts, and easy integration with existing DR systems) indicates that the triple-layer detector can potentially bring DE imaging to real-time and mobile DR, something that does not exist today.
Dual-energy Imaging, Flat-panel Imagers, DQE