A prototype low-energy, multi-pinhole SPECT system for small-animal imaging

Small-animal nuclear imaging applications require both good spatial resolution and good sensitivity. The use of a detector with outstanding spatial resolution allows high-resolution pinhole imaging to be done with only modest magnification. Consequently, multi-pinhole imaging can be done with significantly reduced multiplexing compared to what would be encountered at an equivalent spatial resolution using a conventional scintillator-based system. We present tomographic images obtained with our prototype silicon imaging system. The silicon detector is a double-sided strip detector of 300 micrometer thickness and 50 micrometer strip pitch with an active area of 28mmtimes63mm. The imaging aperture is a multiple-pinhole collimator made from molybdenum. This system is suitable for imaging the low-energy emissions (27-35 keV) from the decay of iodine-125. We present plans for a next-generation silicon-based imaging system that will significantly improve the sensitivity