<title>Development of a CdZnTe-based small field-of-view gamma camera</title>

Abstract

The interest in the use of CdZnTe room-temperature, solid-state detectors for Nuclear Medicine applications continues to grow. Efforts are underway at several companies and institutes to develop CdZnTe detector systems to compete with existing scintillator-based Large Field of View (LFOV) gamma cameras. eV PRODUCTS is focusing on the development of Small Field of View (SFOV) gamma cameras using monolithic CdZnTe detector arrays coupled to custom designed, low noise analog read-out electronics. Electronic noise in the ASIC's has been minimized, and is typically less than 100 e<SUP>-</SUP> rms (0pF). The detector readout system has the capability to perform automatic energy calibration, gain setting and discrimator level setting, along with a comprehensive self-diagnostic routine. The complete integrated unit includes a bias voltage generator, counters and communication control. A first prototype 256-channel device has been developed and constructed, with pixel dimensions of 1.8 x 1.8 mm<SUP>2</SUP>, on a 34 x 34 x 5mm3 monolithic CdZnTe detector. Results obtained from this system will be presented, showing both the energy resolution and uniformity data for several arrays. The energy resolution has been demonstrated to be 3-5% FWHM 140 keV, with photopeak efficiencies of 70-80%.