State-of-the-art 32 cm field-of-view digital PET/CT system: preliminary study for protocols optimization and DRLs update

The aim of this study was to assess the impact of a state-of-the-art 32 cm axial field-of-view GE Omni Legend PET/CT system on administered activity and image quality, and to update Diagnostic Reference Levels (DRLs). System performance was evaluated using NEMA NU 2-2018 measurements and EARL2 accreditation tests. A comparison with the previous 5-ring GE Discovery IQ scanner was performed to analyze the administered activity, scan duration and image quality with and without Artificial Intelligence driven reconstruction. A retrospective analysis of standard-sized adult examinations was conducted to derive updated DRLs values. Omni Legend demonstrated improved sensitivity and Noise Equivalent Count Rate, enabling up to 60% reduction in injected activity while maintaining or improving image quality. Deep learning reconstruction enhanced image quality, particularly at lower administered activities. The DRLs were lower than the national and international reference levels, supporting dose optimization in clinical practice.