A back-projection approach to coded aperture imaging for SPECT applications

This work applies a back-projection approach to the reconstruction of images obtained with a 3D near-field coded aperture camera, a method derived from that used to analyse astronomical data collected by the INTEGRAL/IBIS instrument.(1) The method used in this paper is a form of deconvolution that updates the image as the camera or the object under observation is moving, and as such could be applied to dynamic studies or as a real-time surgical probe. Multi-isotope parathyroid imaging has been identified as one of the optimal applications of this technique, where high sensitivity and high energy resolution would permit the differentiation between thyroid and parathyroid tissues on the surgical table, and aid in different types of thyroid surgery. The back-projection technique is combined with a 3D version of the iterative CLEAN algorithm, which reduces the effect of the systematic noise intrinsic to imaging with a non-perfect aperture.