Performance Evaluation and Compatibility Studies of a Compact Preclinical Scanner for Simultaneous PET/MR Imaging at...

Area of Science:

• Medical Imaging
• Preclinical Research
• Instrumentation

Background:

• Simultaneous positron emission tomography (PET) and magnetic resonance imaging (MRI) offer synergistic benefits for preclinical research.
• Developing integrated PET-MRI systems presents challenges in managing interferences and optimizing performance.

Purpose of the Study:

• To design and evaluate a new compact preclinical PET-MRI system for simultaneous scanning.
• To assess the performance characteristics of the integrated PET and MRI subsystems according to international standards.

Main Methods:

• A compact PET system with SiPM-based detectors was integrated into a 7 T dry magnet MRI system.
• System performance was evaluated using phantoms (rat and mouse sizes) and NEMA NU4-2008 standards.
• Interferences between PET and MRI subsystems during simultaneous scans were investigated and addressed.

Main Results:

• The system achieved peak noise equivalent count rates (NECR) of up to 426.9 kcps for mouse imaging.
• Spatial resolutions ranged from 1.69/3.19 mm (FWHM/FWTM) at the FOV center.
• Peak absolute sensitivity was 7.9% without the RF coil. Image quality metrics, including non-uniformity and spill-over ratios, were within acceptable ranges.
• Linearity of image count versus activity was maintained up to 40 MBq.

Conclusions:

• The designed compact preclinical PET-MRI system enables simultaneous data acquisition.
• The system demonstrates robust performance and preserves both qualitative and quantitative data integrity during combined scans.
• This integrated system is suitable for advanced preclinical imaging studies.