Performance evaluation of a parallel-hole collimated detector module for animal SPECT imaging

We have built and investigated a detector module for animal SPECT imaging, especially for use in large field of view （FOV） conditions. The module consists of a PMT-based detector and a parallel-hole collimator with an effective area of 80 mm× 80 mm. The detector is composed of a NaI scintillation crystal array coupled to four H8500 position sensitive photomultiplier tubes （PS-PMT）. The intrinsic energy resolution of the detector is 11.5% at 140 keV on average. The planar spatial resolution of the module changes from 2.2 mm to 5.1 mm at different source-to-collimator distances with an unchanged sensitivity of about 34cps/MBq. Additionally, the SPECT Micro Deluxe Phantom imaging was performed with a radius of rotation （ROR） of 40 mm. Using the FBP reconstruction algorithm, a high performance image was obtained, indicating the feasibility of this detector module.