Large area scintillation detectors applied in gamma cameras as well as Single Photon Computed Tomography (SPECT) systems, have a major role in in-vivo functional imaging. Most of the gamma detectors utilize hexagonal arrangement of Photomultiplier Tubes (PMTs). In this work we applied large square-shaped PMTs with row/column arrangement and positioning. The Use of large square PMTs reduces dead zones in the detector surface. However, the conventional center of gravity method for positioning may not introduce an acceptable result. Hence, the digital correlated signal enhancement (CSE) algorithm was optimized to obtain better linearity and spatial resolution in the developed detector. The performance of the developed detector was evaluated based on NEMA-NU1-2007 standard. The acquired images using this method showed acceptable uniformity and linearity comparing to three commercial gamma cameras. Also the intrinsic and extrinsic spatial resolutions with low-energy high-resolution (LEHR) collimator at 10 cm from surface of the detector were 3.7 mm and 7.5 mm, respectively. The energy resolution of the camera was measured 9.5%. The performance evaluation demonstrated that the developed detector maintains image quality with a reduced number of used PMTs relative to the detection area.

Purpose: Cardiac SPECT imaging is widely used for many clinical practices such as the diagnostic of coronary artery diseases (CAD) and Myocardial Perfusion Imaging (MPI). In this work, we introduced the ProSPECT system, a dedicated cardiac SPECT system with open-gantry design. Materials and Methods: In this study we assessed the performance of the system based on NEMA-NU1-2007 standards. The ProSPECT system was characterized by measurement of planar, tomographic and clinical parameters. Results: Planar measurements showed 7.6 mm and 8.9% of spatial resolution and energy resolution at 140 keV, respectively. The tomographic resolution at 250 mm radius of rotation was 12.3 mm. Also, the maximum LOR and COR error for the tomographic imaging are obtained 1.1 mm and 1.8 mm, respectively. The clinical images that obtained using the system were confirmed by nuclear medicine physician expert. Conclusion: It concluded that the ProSPECT imaging is qualified for cardiac SPECT imaging.