Imaging performance of tiled solid-state detectors

This investigation presents a large area solid-state detector (SSD) based on tiled cadmium zinc telluride (CZT) modules for low energy SPECT nuclear medicine applications. The CZT modules used to construct this detector require registered collimation due to the winner-take-all (WTA) readout architecture and charge sharing between pixels. To address this limitation two registered square-hole collimators were fabricated to match the pixel pitch of the SSD. Spatial resolution for each registered collimator was compared to a standard VXGP collimator on a NaI(Tl) EPIC detector. Studies of 3D Hoffman brain and Jaszczak phantoms show improved image quality. Furthermore, Rollo 2D phantoms show improved contrast and resolution with fewer counts in the SSD images. However, SSD only provides equivalent SPECT imaging performance for cardiac studies. Comparisons of measured data to simulation models have been used during this investigation to assess SSD detectors and collimation techniques for future camera designs.