Evaluation of a digital bismuth germanium oxide PET/CT system according to the Japanese brain tumor phantom test for 18F-fluciclovine imaging.

The Omni Legend (GE Healthcare), equipped with a digital bismuth germanium oxide PET/CT system, has been recently developed. However, the performance of the Omni Legend without a time-of-flight (TOF) system for ¹⁸F-fluciclovine imaging is still unclear. Therefore, this study evaluated the image quality of the Omni Legend according to the Japanese brain tumor phantom test (JBT) criteria, and assessed its potential use for ¹⁸F-fluciclovine imaging. This study followed the JBT procedures. A brain tumor phantom, which includes six hot spheres of different diameters, was filled with an ¹⁸F-fluorodeoxyglucose solution with a radioactivity concentration ratio of 3 (spheres):1 (background). PET scanning was performed using the Omni Legend with a 30-min list mode acquisition. The PET data were reconstructed using an ordered subset expectation maximization (OSEM), an OSEM with point spread function (OSEM + PSF), and a Bayesian penalized likelihood (BPL) under standard clinical parameters. The image quality was evaluated using the JBT criteria, including contrast for a 7.5-mm sphere, recovery coefficient (RC) for a 10.0-mm sphere, standardized uptake value of total background (SUV_TOT), and detectability for a 7.5-mm sphere. The contrast, RC, and SUV_TOT were 25.1%, 0.70, and 1.00, respectively in OSEM; 25.8%, 0.80, and 0.99 in OSEM + PSF; and 33.8%, 0.93, and 0.99 in BPL. The 7.5-mm sphere was detected by all three methods. All of the JBT criteria were satisfied, regardless of the PET image reconstruction methods. This study demonstrated that the Omni Legend without TOF satisfies all JBT criteria and has the potential to provide high-quality images in ¹⁸F-fluciclovine imaging.