Study of Spectral CT Based on a Photon Counting Detector

The purpose of this paper is to evaluate the performance of the photon counting detector in CT. We tested the performance of a photon counting detector based on CZT, and built a tabletop X-ray CT scanner. Firstly, in order to reduce non-uniformity of the detectors, calibration of the energy thresholds and dead pixel correction were performed. Then calibration of the energy thresholds was applied to determine the working energy threshold of the detector. In the end we acquired projection data with two energy bins(36 and 45 ke V). The ART-TV algorithm based on the compressed sensing was performed to reconstruct the incomplete projection data.