Characterization and comparison of X-ray detectors for use in small animal imaging

In this paper we describe the results of our characterization of four X-ray detectors in order to determine their relative strengths and weaknesses for use in the CT component of a dedicated CT-SPECT scanner that we are developing for small animal imaging. Two of the four detectors are custom-built charge coupled device (CCD)-based detectors and the other two are commercially available detectors based on complementary metal oxide (CMOS) technology. This paper describes the design of each detector and presents the results of measurements of imaging characteristics such as the detector dark noise, sensitivity, the modulation transfer function (MTF), the noise power spectrum (NPS), and the detective quantum efficiency (DQE)- Compared to the CMOS detectors, the CCD based detectors exhibit superior DQE over most of the frequency range of interest.