Multi-Energy, Single-Isotope Pinhole Imaging Using Stacked Detectors

Nuclear imaging of small animals has proven to be an excellent tool for studying models of human disease and in drug development. Silicon double-sided strip detectors (DSSDs) have been adapted for imaging of low-energy emissions from radioisotopes such as 123I and 125I We examined stacking a DSSD with a modular scintillation camera (Modcam) from the FastSPECT II design for simultaneous imaging of the low- and high-energy emissions of 123I. This constitutes a specific implementation of the synthetic collimator. We also considered a novel aperture, the `sandwich aperture' to maintain sensitivity in the Modcam projection and higher resolution in the DSSD projection. Through simulations and basic measurements we found that stacked detectors and the sandwich aperture do not distort the point spread function of either imaging system significantly.