A New Architecture for Pixellated Solid State Gamma Camera Used in Nuclear Medicine

The purpose of this paper is to introduce a novel technique for acquiring and reconstructing planar or tomographic images obtained using a gamma camera. The aim is to overcome the sensitivity-spatial resolution tradeoff for conventional Anger gamma cameras. The future generation of solid state gamma cameras will benefit from the recent advances in CdZnTe (CZT) detector performances. Previous studies have shown that pixellated CZT detectors have a high energy resolution, good detection efficiency and a high intrinsic spatial resolution. Moreover, these detectors provide important additional information: the depth of interaction (DOI). In this paper, we introduce the HiSens (High Sensitivity) architecture: an original collimator architecture associated with a CZT pixellated detector that takes advantage of such performances, particularly in terms of DOI information and an adapted method of iterative reconstruction. We explain about the ability of our CZT detector, associated with specific electronic processing, to obtain accurate DOI information on a 5 mm-thick CZT detector. We have used SINDBAD simulation tool to evaluate the performance of the HiSens architecture. We describe an adapted iterative reconstruction using the CZT DOI information in order to improve image quality. Then we show preliminary simulation results of the HiSens architecture performances.