NUCAM3-a gamma camera based on segmented monolithic CdZnTe detectors

NUCAM3 is the latest generation of solid-state pixelated gamma cameras developed at Soreq NRC. The NUCAM3 head is based on segmented pad monolithic CdZnTe detectors that currently provide a useful field of view of 18.5 cm×20.1 cm. The camera is designed for cardiac SPECT, breast scintimammography, thyroid, and other small organ evaluation. The camera contains 528 detectors. Each detector is 5 mm thick and is divided to a matrix of 16 square pixels, with a pitch of 2.1 mm. The use of pixelated CdZnTe detectors and low-noise electronics provides a camera with an average energy resolution of 4.5% full width half maximum (FWHM) at 140.5 keV and 9.5% FWHM at 59.6 keV and an intrinsic spatial resolution of 2.1 mm, regardless of the photon energy. We present the analysis of over 1300 CdZnTe monolithic detectors, the physical and imaging characteristics of the NUCAM3 camera and their comparison to state of the art Anger cameras. We show the advantages of CdZnTe technology, which are due to the camera pixel structure and superior energy resolution. These advantages lead to better detectability of small size cold and hot lesions in a scatter environment.