The new PET CT scanner has recently shown multiple technological advances in hardware and software specifications as well as in acquisition methodology to improve image quality. In this study we explored the merits of digitals detectors in contrast to conventional photomultiplier tubes systems and how it adds additional advantage in the terms of increased sensitivity, improve the image resolution across the field of views leading to highest lesion detectability Technology

.Materials and methods: The performance characteristics such as system sensitivity, spatial resolution, count-rate performance, accuracy of attenuation and scatter correction, TOF performance, and image quality were assessed and determined by using NEMA NU 2 (published by the National Electrical Manufacturers Association , provided by the vendor for each PET/CT scanner .The measurements For the two PET systems was evaluated , first scanner based on new-generation detectors of digital silicon photomultipliers (SiPM) and the other one with conventional PMT and TOF.

The digital PET/CT (dPET/CT) systems outperforms the analogue PET(aPET/CT) in every NEMA test: revealed a transverse spatial resolution of 4.29 at 1 cm offset from the centre of the field of view (measured with A FDG source), compared to 5.99 mm shown by the aPET. Furthermore, an increase in sensitivity of 70.3%, a 65% higher peak noise equivalent count-rate, and a higher contrast recovery were reached with respect to the aPET; the timing resolution improved from 540 ps on the aPET to 210 ps on the dPET.

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The dPET/CT instrumentations demonstrated a higher sensitivity, better presentation in term of performance under high count-rate conditions and better image quality than the aPET/CT system. These findings suggest that overall superior images quality might be achieved under routine scanning schedules with new  dPET/CT, thus enabling shortening acquisition time and reducing radiotracer dose. In clinical PET/CT imaging practice, these factors should be considered and organized to perform the best possible image quality and a low radiation dose to the patient as well as reasonable acquisition times, thus reaching a fast workflow.

I would like to express my special thanks of gratitude to the Director General of the Jaber Al-Ahmad Center, Dr. Fahd Murafi,  who gave us  the opportunity to do  a lot of Research
and also my colleagues at the Physics Unit, Jaber Al-Ahmad Center
 

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