Performance evaluation of a small-animal PET scanner with 213 mm axis using NEMA NU 4-2008

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Biomedical Engineering

Background:

• Long-axis positron emission tomography (PET) is an emerging research area offering enhanced sensitivity and counting performance for various imaging applications.
• Its advantages include low-dose, rapid, and whole-body dynamic imaging capabilities.

Purpose of the Study:

• To evaluate the performance of a novel long-axis animal PET system designed for whole-body rat imaging.
• The system utilizes lutetium-yttrium orthosilicate and silicon photomultiplier technology.
• Performance was assessed against National Electrical Manufacturers Association (NEMA) NU 4-2008 standards.

Main Methods:

• The PET system's performance was evaluated using NEMA NU 4-2008 standards.
• Key metrics included spatial resolution, sensitivity, counting rate performance, scatter fraction (SF), and image quality.
• A rat imaging study was conducted to assess the system's imaging capabilities.

Main Results:

• The system achieved excellent spatial resolution (0.88 mm FWHM with 3D-OSEM-PSF).
• Peak absolute sensitivity was 10.31% (250-750 keV).
• For a rat-like phantom, the scatter fraction was 26.8% and peak noise equivalent counting rate (NECR) was 682.5 kcps.

Conclusions:

• The evaluated long-axis PET system demonstrates high sensitivity and count rate performance.
• These results indicate its potential for high-quality, whole-body dynamic imaging in rats.
• The system represents a significant advancement in preclinical PET imaging technology.