Ultra-low dose imaging in a standard axial field-of-view PET

Area of Science:

• Nuclear Medicine
• Radiological Imaging
• Medical Physics

Background:

• Ultra-low dose (ULD) PET/CT imaging offers significant advantages but faces adoption challenges due to system costs and AI limitations.
• Long-axial field-of-view (LAFOV) PET/CT systems are expensive and scarce, while AI integration is system-specific.
• Advancements in AI and technology are bridging the gap between standard axial field-of-view (SAFOV) and LAFOV PET/CT systems for ULD imaging.

Purpose of the Study:

• To evaluate the capabilities of ULD PET/CT imaging on a latest SAFOV PET/CT device.
• To assess dosimetry and compare clinical outputs (kidney function, brain uptake) against established models and databases.
• To determine the feasibility of achieving high-quality imaging with reduced radiation exposure in a clinical setting.

Main Methods:

• A patient received 16.4 MBq of 18F-FDG and underwent dynamic (30 min) abdominal and static (74 min) whole-body acquisition on a GE Omni PET/CT scanner.
• Dosimetry was computed, and clinical data were compared to kidney models and normal brain uptake databases.
• Signal-to-noise ratio (SNR) was calculated and compared to reported values for LAFOV systems.

Main Results:

• The effective PET dose was 0.27 ± 0.01 mSv, with absorbed doses of 0.56 mGy (brain), 0.89 mGy (heart), and 0.20 mGy (kidneys).
• Kidney activity concentration closely matched the kidney model, and brain uptake showed normal z-scores.
• The achieved SNR of 13.1 was comparable to values reported for LAFOV PET/CT systems.

Conclusions:

• ULD PET imaging is feasible and effective on SAFOV PET/CT devices, offering diagnostic quality previously thought unattainable.
• This approach provides a viable pathway to increase ULD imaging accessibility, overcoming limitations of expensive LAFOV systems.
• The findings support the potential of ULD PET/CT in SAFOV systems for routine clinical use with reduced radiation burden.