A Prototype High-Resolution Small-Animal PET Scanner Dedicated to Mouse Brain Imaging.

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Biomedical Engineering

Background:

• Small-animal PET scanners are crucial for preclinical research, particularly in neuroscience.
• Achieving high spatial resolution is essential for detailed imaging of small biological structures like the mouse brain.

Purpose of the Study:

• To develop a prototype small-animal PET scanner with high and uniform spatial resolution.
• To enable detailed imaging of the mouse brain using advanced detector technology.

Main Methods:

• Developed a PET scanner with 16 tapered dual-ended-readout depth-encoding detectors.
• Utilized lutetium oxyorthosilicate scintillator elements and position-sensitive avalanche photodiodes.
• Employed 3D maximum-likelihood expectation maximization reconstruction for image processing.

Main Results:

• Achieved an average axial spatial resolution of 0.61 mm and a depth-of-interaction resolution of 1.7 mm.
• Demonstrated a transaxial field of view of 30 mm, accommodating the entire mouse brain.
• Resolved microphantom rods as small as 0.5 mm and achieved 0.6 mm in vivo resolution in mouse heads.

Conclusions:

• The prototype PET scanner achieves spatial resolution close to the physical limits for small-bore systems.
• Future work includes extending the axial field of view and enhancing sensitivity by adding more detector rings.