Single exposure dual-energy digital radiography

This study presents preliminary results of single kVp dual-energy computed radiography using laser stimulable luminescent phosphor image plate detectors. The single kVp 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 stimulation, 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 demonstrate the quality of the resulting calibration material equivalent images.