Simulation of sensitivity and NECR of entire-body PET scanners for different FOV diameters

The current Positron Emission Tomography (PET)s design is towards improving sensitivity. In this paper, we investigated the advantage of establishing an entire-body PET scanner. Despite of its high cost production, entire-body DOI PET scanners were expected to offer many benefits such as shorter time and dynamic PET acquisition, higher sensitivity and NECR. We simulated sensitivity and NECR test for several scanner length and diameter using GATE. Our experiment showed that the entire-body PET of 2 m long and 80 cm diameter achieved gain as high as 68 times in terms of system sensitivity and 20.48 times for NECR peak value in comparison to the conventional 20-cm PET scanner. The entire-body scanner with smaller diameter of 60 cm, in addition to its cost-saving advantage, has achieved a gain of 80 times in terms system sensitivity in comparison to the conventional 80 cm diameter scanner with 19.2 cm FOV length. It also yield a high NECR peak value of around 830 kcps. However, this value is smaller compared to other larger scanner due to higher grouping dead-time loss experienced by such scanner.