A new CdZnTe-based gamma camera for high resolution pinhole SPECT

We have developed and tested a pixelated detector for pinhole SPECT. The 80/spl times/80 detector has a pixel size of 2.5/spl times/2.5 mm/sup 2/ and incorporates the room-temperature solid-state semiconductor CdZnTe which offers direct charge conversion and good stopping power for radionuclides used for small animal SPECT. To optimize low energy photon detection, the detector is operated at a temperature of 15/spl plusmn/1/spl deg/C, and has been designed to minimize absorption losses for photons entering the active detector material. The CdZnTe detector demonstrates good uniformity, spatial resolution and energy resolution. Transmission images obtained with an /sup 125/I point source demonstrate its low-energy performance, while dual isotope images were obtained using /sup 99m/Tc and /sup 201/Tl. The detector therefore offers good performance for high-resolution small animal SPECT.