Performance evaluation of the Biograph Trinion EP2 PET/CT system according to NEMA NU2-2018.

Abstract

This study evaluates the performance of the Siemens Biograph Trinion EP2 whole-body PET/CT system according to the NEMA NU2-2018 standard. Following the NEMA NU2-2018 standard, spatial resolution was measured using a 22Na point source in air, sensitivity was calculated from consecutive measurements of a 18F containing line source surrounded by aluminum tubes, count rate performance, accuracy of corrections assessment and TOF resolution was based on measurements of an 18F line-source inside scatter phantom. PET-CT co-registration accuracy was assessed by radioactive and radiation dense point sources, image quality was evaluated using a NEMA IQ phantom. Measurements were done using implemented NEMA NU2-2018 acquisition protocols on a Siemens Biograph Trinion EP2 PET/CT system. The Trinion EP2 showed a spatial resolution between 4.0 and 4.4 mm FWHM at the center of the FOV. Sensitivity was measured with 13.8 kBq/MBq and the peak noise equivalent count rage of 143 kcps measured at 14.8 kBq/mL with a corresponding scatter fraction of 37.5%. The maximum average error was 1.6% between 1 kBq/mL and 14.8 kBq/mL and a TOF resolution of 241 ps was measured at a clinical activity concentration. Contrast recoveries between 47.2% and 81.6% were measured in the image quality phantom when using standard reconstructions. The Biograph Trinion EP2 PET/CT system shows a good overall performance providing a decent image quality comparable to state-of-the-art PET/CT systems with standard axial FOV between 20 and 30 cm.