Imaging performance measurements of SiliSPECT

SiliSPECT, a multi-pinhole, multi-detector SPECT system, was designed to image targeted-regions of rodents at sub-300 ¿m resolution with motionless data acquisition and a special reconstruction method. High spatial resolution is achieved with thick silicon double-sided strip detectors (DSSDs) and 250 ¿m pinhole apertures. Each of the two heads contains two stacked DSSDs, which improves total detection efficiency. The stacked detector, multi-pinhole aperture configuration also permits experimental validation of simulated synthetic collimator image reconstruction. SiliSPECT was assembled and operates stably with forced air cooling. Performance measurements, including intrinsic detection efficiency, sensitivity, and dead time were made. To reconstruct tomographic images with a calculated system matrix requires accurate estimation of geometric calibration parameters. We present details of our approach for determining these parameters.