Abstract
Positron emission tomography (PET) is a widely used imaging modality for the diagnosis and treatment of oncologic diseases. In this study, we evaluated the performance of digital PET/CT systems using subcentimeter microsphere inserts in a NEMA IEC Body Phantom. The digital system was compared with a non-digital PET scanner using the same image reconstruction method. Results revealed that the digital system maintained higher detectability for smaller spheres with an average of 1 Likert score higher for lesions under 7.9 mm, indicating its ability to detect smaller lesions more effectively than the non-digital system. Furthermore, we observed that the drop-off in contrast recovery occurs at smaller microspheres in the digital PET system compared with that for a non-digital PET scanner. This suggests that digital PET may require the use of smaller spheres in image quality testing to ensure accurate comparison of performance between digital systems. This implies that digital systems can more accurately and effectively distinguish subtle differences in image intensity and spatial distributions of intensity, leading to improved lesion visibility and detection, which is likely due to the superior imaging characteristics offered by underlying detection technology.