Evaluation of a BGO-Based PET System for Single-Cell Tracking Performance by Simulation and Phantom Studies

Area of Science:

• Medical Imaging
• Nuclear Physics
• Biophysics

Background:

• Positron Emission Tomography (PET) is crucial for tracking radioactive sources.
• Scanner background noise can limit the precision of PET tracking systems.
• The Genisys4 PET system, with low intrinsic background, is explored for enhanced tracking capabilities.

Purpose of the Study:

• To evaluate the tracking performance of the Genisys4 PET system for moving point sources.
• To compare the Genisys4's tracking capabilities against the Inveon PET system, considering background noise effects.
• To assess the feasibility of tracking low-activity and fast-moving sources with the Genisys4.

Main Methods:

• Simulated position-dependent sensitivity of the Genisys4 using Geant4 Application for Tomographic Emission (GATE).
• Reconstructed trajectories of helically moving point sources with varying activity and speed from list-mode data.
• Validated tracking performance using a physical phantom with (18)F-labeled droplets.

Main Results:

• Genisys4 demonstrated a higher velocity-to-activity ratio threshold (< 0.29 mm/decay) for < 2 mm localization error compared to Inveon (< 0.13 mm/decay).
• Physical phantom validation yielded < 1 mm localization error for moving (18)F droplets under tested conditions.
• Simulated sensitivity showed good agreement with measured activity (Pearson's R = .64, P << .05).

Conclusions:

• The Genisys4 PET system is suitable for tracking moving point sources, even those with low activity and higher speeds.
• Results suggest the Genisys4's low background noise is advantageous for precise tracking applications.
• The study confirms the feasibility of using Genisys4 for tracking small, low-activity, point source-like objects.