Protocols for Harmonized Quantification and Noise Reduction in Low-Dose Oncologic ¹⁸F-FDG PET/CT Imaging

Area of Science:

• Nuclear Medicine
• Medical Imaging
• Radiochemistry

Background:

• Optimizing 18F-FDG PET/CT protocols is crucial for accurate oncologic imaging.
• Current protocols often prioritize either quantitative accuracy or noise reduction, not both.
• Harmonized quantification and noise control are essential for reliable diagnostic and therapeutic assessments.

Purpose of the Study:

• To develop and evaluate optimized 18F-FDG PET/CT acquisition and reconstruction protocols.
• To achieve harmonized quantitative accuracy with acceptable noise levels.
• To establish protocols as a function of acquisition parameters and patient body mass.

Main Methods:

• Utilized the IEC/NEMA PET phantom with variable counting statistics for protocol development.
• Reconstructed phantom and patient data using 3D OSEM and PSF methods.
• Analyzed image noise and contrast recovery coefficient (CRC) variability against European Association of Nuclear Medicine guidelines.

Main Results:

• PSF reconstruction demonstrated reduced noise and lower CRC variability compared to OSEM3D at harmonized quantification levels.
• This suggests PSF may allow for lower injected activity while maintaining performance.
• Optimized protocols were derived using phantom-to-subject translational analysis.

Conclusions:

• PSF reconstruction with a 7-mm postprocessing filter provides harmonized quantification and acceptable noise.
• This can be achieved with a 260 MBq·s/kg acquisition parameter.
• OSEM3D with a 5-mm filter offers similar performance at 401 MBq·s/kg.