RESUMEN
The general-purpose particle transport code, FLUKA, was used to model the GE Advance Positron Emission Tomography (PET) scanner (GEMS). The required spatial and energy data were extracted using the FLUKA phase-space card, USERDUMP, with its user-routine, mgdraw, consisting of full-events information. Several point and volumetric sources were modeled and the corresponding locations of the sources were identified using three different proposed algorithms which eliminate the use of conventional image-reconstruction packages. Also, having extracted the time information, the time-of-flight approach in PET (TOF-PET) was used to reconstruct the images of several volumetric positron-emitting sources, representing the best results according to the chi-square analysis data. The post-processing calculations, both on CPU and GPU, were undertaken either with MATLAB or Fortran programming.