Sub-0.5 mm Resolution PET Scanner With 3-Layer DOI Detectors for Rodent Neuroimaging.

Area of Science:

• Preclinical imaging
• Medical physics
• Neuroscience

Background:

• Spatial resolution is critical for preclinical positron emission tomography (PET) in mouse brain imaging.
• Existing PET scanners have limitations over 0.5 mm resolution, causing partial volume effects in small structures.
• High-resolution imaging is essential for accurate quantification of mouse brain function.

Purpose of the Study:

• To present initial results from a novel, dedicated mouse brain PET scanner.
• To demonstrate sub-0.5 mm spatial resolution for enhanced preclinical imaging.
• To evaluate the scanner's performance for visualizing small mouse brain structures.

Main Methods:

• Developed a dedicated mouse brain PET scanner with a 48 mm ring diameter and 23.4 mm axial coverage.
• Utilized 3-layer stacked lutetium yttrium oxyorthosilicate crystals for depth-of-interaction encoding.
• Characterized performance using National Electrical Manufacturers Association NU4-2008 standards and in vivo imaging with ¹⁸F-FITM and ¹⁸F-FDG.

Main Results:

• Achieved an average radial resolution of 0.67±0.06 mm (filtered back projection).
• Successfully identified 0.45 mm diameter rods using iterative reconstruction.
• Demonstrated the first separate identification of mouse hypothalamus, amygdala, and cerebellar nuclei.

Conclusions:

• The developed PET scanner achieves sub-0.5 mm resolution, surpassing previous limitations.
• This advancement allows for high-resolution visualization and accurate quantification of small mouse brain structures.
• Enables unprecedented detail in preclinical mouse brain functional imaging.