Dual Energy Radiography Using A Single Exposure Technique

This study presents preliminary results of single exposure dual energy computed radiography using laser stimulable luminescent phosphor imaging plate detectors. The single exposure technique makes use of four of these plates in a single cassette, each plate acting as an X-ray filter to the next so that the energy separation required for the dual energy basis decomposition is achieved. An analysis to determine the best operating technique for the chest is performed using computer simulation, and was found to be 85 kVp and 14 mAs. This technique yields the same entrance exposure value as is used clinically, so that the information for the decomposition is obtained without additional dose to the patient. The Iso-transmission line technique was used as the decomposition algorithm. A humanoid chest phantom was used to test the quality of the resulting calibration material equivalent images. The quality of the images, although slightly inferior to that of dual exposure technqiues, seem acceptable for clinical application.