Ultrahigh-resolution small-animal imaging using a silicon detector

We have developed a prototype ultrahigh-resolution small-animal imaging system that utilizes a silicon detector with a multiple-pinhole aperture. This system is suitable for imaging low-energy photons such as those from I-125 decay (27.2-35.5 keV) or the X-rays from I-123 decay (27.2-31.8 keV). The silicon detector is a double-sided strip detector of 300-micrometer thickness and 50-micrometer strip pitch, with 560 strips on one side and 1260 strips on the other. The readout utilizes VaTaGP2.2 ASICs from IDEAS ASA, Norway. When the detector is coupled with a multiple-pinhole aperture and operated in a synthetic-collimator configuration it should be possible to do tomographic image reconstructions without rotation of either the object or imager.