Improvements in CdZnTe detection system for combined X-ray CT and SPECT

Combined emission-transmission imaging systems that perform both X-ray CT and SPECT have the potential to correlate anatomical and physical data, and to improve the accuracy of in vivo radiopharmaceutical quantitation. A detection system suitable for the combined CT/SPECT system must achieve both excellent energy resolution at low count rates for radionuclide imaging and must be compatible with the high flux rates and wide dynamic range encountered in X-ray imaging. We therefore are investigating the use of a pixellated CdZnTe for CT/SPECT imaging. Alternative electrode geometries of CdZnTe detectors for SPECT have been investigated with numerical simulation.