ارزیابی سیستم تصویربرداری ترکیبی کامپتون-مقطع‌نگاری گسیل پوزیترون به منظور بهبود کیفیت تصویر با استفاده از شبیه‌سازی مونت کارلو

The combination of Compton imaging and positron emission tomography, which is also known as the combined Compton-positron emission tomography (Compton-PET) imaging system, has received attention due to the improvement of spatial resolution and imaging sensitivity compared to PET imaging alone. Compton-PET simulated system consists of two concentric detector rings. The inner ring with a smaller diameter is called the Compton scattering detector, the scatterer, and the outer ring, which has the dual use of Compton scattering detection and PET detector, is called the absorber. Considering the importance and many applications of PET imaging, the purpose of this research is to use the Compton-PET imaging approach and simulate this system with the 4GEANT tool, to achieve a better image output by increasing the spatial resolution. In this simulation, the geometry of two detector rings consisting of cubic crystals for the absorbing detector and the scattering detector inside the universe was considered. The gamma radiation source of the type that emits gamma with energy 511 keV was placed in the Micro-Derenzo phantom. In this research, image reconstruction is done using the MLEM iteration algorithm with 20 iterations. According to the obtained results, the value of FWHM is reported as 2.8 mm. For validation, the results were directly compared to the NEMA NU 2-2007 standard, which is provided for the measurement and reporting of positron emission tomography (PET) performance parameters.