Impact of the new ultra-high sensitivity mode in a long axial field-of-view PET/CT.

Objective: Long axial field-of-view (LAFOV) PET/CT showed improved performance resulting from higher sensitivity. The aim was to quantify the impact of using the full acceptance angle (UHS) in image reconstructions with the Biograph Vision Quadra LAFOV PET/CT (Siemens Healthineers) compared to the limited acceptance angle (high sensitivity mode, HS).

Methods: 38 oncological patients examined on a LAFOV Biograph Vision Quadra PET/CT were analysed. 15 patients underwent [F]FDG-PET/CT, 15 patients underwent [F]PSMA-1007 PET/CT, and 8 patients underwent [Ga]Ga-DOTA-TOC PET/CT. Signal-to-noise ratio (SNR) and standardised uptake values (SUV) were used to compare UHS and HS with different acquisition times.

Results: The SNR was significantly higher for UHS compared to HS over all acquisition times (SNR UHS/HS [F]FDG: 1.35 ± 0.02, p < 0.001; [F]PSMA-1007: 1.25 ± 0.02, p < 0.001; [Ga]Ga-DOTA-TOC: 1.29 ± 0.02, p < 0.001).

Conclusion: UHS showed significantly higher SNR opening the possibility of halving short acquisition times. This is of advantage in further reduction of whole-body PET/CT acquisition.