A section of a curved pixelated NaI(Tl) detector for SPECT/TCT

Previously we described a small detector module as a basis for C-SPECT´s detector system [1]. The detector module was based on a scintillator block comprised of an array of 36×17 of 2.25 × 2.75 × 10 mm3 NaI(Tl) pixels in a 2.5 × 3 mm pitch. The module was decoded by an array of 51-mm-diameter single-anode photo-multiplier tubes (PMTs). Here we present a prototype consisting of 3 large detector modules (each with an array of 36×56 pixels) with the same 2.5 × 3 mm pixel pitch, and decoded by 31 PMTs in a similar fashion as the small module. The analog signals from the PMTs were digitized by, and the events were processed with the initial release of OpenPET´s [2] hardware and firmware, respectively. The 3-detector prototype was assembled and tested [3]. Preliminary experiments included taking intrinsic floods of the 3-detector module and qualitative demonstration of resolution/ sensitivity tradeoff performance using C-SPECT´s slit-slat collimator [4], without pixel identification or detector corrections. The decoding maps for each detector module show good visual delineation of the pixels in majority of the detector´s field of view (FOV). The preliminary resolution/sensitivity tradeoff data shows qualitatively expected behavior when switching between the high-resolution and the high-sensitivity mode of the collimators.