Development of a multi-pinhole brain SPECT system with CdZnTe semiconductor detectors

The purpose of our research is to develop a new brain single photon emission CT (SPECT) system with semiconductor detectors. The gamma camera with semiconductor detectors with multi-pinhole enables us to make a compact brain SPECT system. In this paper we evaluated the performance of the proposed data acquisition system by simulations in terms of the number of data acquisition angles including the wobbling of the gantry with pinhole collimators. Moreover, we developed a prototype system with three semiconductor detector units to evaluate the proposed method experimentally. In this system, we used three pinhole collimators on the three surfaces of the hexagonal gantry around a targeted object. In front of three surfaces with pinhole collimators, we located three detector units that consisted of ten (5 × 2) CdZnTe modules. The size of a module was 39 × 39 mm² (16 × 16 pixels) and the thickness of the CdZnTe crystal was 5 mm. The results obtained with the simulations confirmed the validity of the proposed brain SPECT system. And the results of the preliminary experiment validated our proposed system.