Performance evaluation of a new CZT detector for nuclear medicine: Soltice

Solstice is a new concept of a gamma camera designed to use the better energy resolution typically available in solid-state detectors. To that purpose, an array of 88 CdZnTe (CZT) crystals was characterized for gamma ray detection performance. The bias voltage was applied to the single electrode cathode side of the crystal (radiation side). The anode side of the individual crystals was further subdivided into 32 anodes connected to a charge sensitive preamplifier/shaper circuit for each pixel that provided a virtual ground potential for the anodes. Overall, the vast majority (85%) of pixels had an energy resolution (FWHM) better than 5% at 140 keV and an outstanding 3.6% FWHM at 140 keV was measured for the overall composite energy resolution over this large population of pixels. Results from the crystal characterization along with overall system performance are discussed.