Alireza Sadremomtaz, - Full professor, Department of Physics, Faculty of Science, University of Guilan, Rasht, Iran
Maziyar Mohammadi Ghalebin - PhD Student, Nuclear Physics, Department of Physics, University of Guilan, Rasht, Iran

Background: Today, Positron Emission Tomography (PET) imaging is of particular importance in nuclear medicine. Using appropriate image reconstruction methods to improve the quality of the images obtained is one of the most important factors. In this study, using the simulation, three types of reconstruction methods for the dual- head PET system were evaluated.Methods: Using the GATE simulation, a small dual- head PET imaging system was simulated in two steady state and 180 ° rotation. The system consists of a LSO scintillator (2 × 2 × 10 mm3) in an array of 20 × 20 and an energy window of 250-600 KeV. A linear narrow-line source with 1 MBq activity was used to calculate spatial resolution. Image reconstruction using three FBP2D, FBP3D and Fore + OSEM methods was performed in STIR software, and spatial resolution was calculated for two steady states and dual-head rotation of the device.Results: After evaluating the accuracy of the program s performance, spatial resolution was calculated using the mean resolution in two directions of X and Y. The results for FBP2D, FBP3D and Fore + OSEM reconstruction methods were 2.83, 3.10 and 2.31 mm, respectively, and for the dual-headed rotation mode, they were obtained 2.54, 3.15 and 2.69 mm, respectively.Conclusion: The results show that when the system is imaging in a steady state, the Fore + OSEM method and the dual-headed rotation mode of the FBP2D and Fore + OSEM methods can be efficient.

Dual-head PET, image reconstruction, spatial resolution