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

We have developed and tested a pixelated detector for pinhole SPECT. The 80×80 detector has a pixel size of 2.5×2.5 mm² 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±1°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 ¹²⁵I point source demonstrate its low-energy performance, while dual isotope images were obtained using ^99mTc and ²⁰¹Tl. The detector therefore offers good performance for high-resolution small animal SPECT.