Micro insert: a prototype full-ring PET device for improving the image resolution of a small-animal PET scanner

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Biomedical Engineering

Background:

• Small-animal Positron Emission Tomography (PET) scanners are crucial for preclinical research.
• Enhancing image resolution in these systems is vital for detailed biological studies.
• Existing scanners often have limitations in achieving high spatial resolution.

Purpose of the Study:

• To develop and evaluate a full-ring PET insert device.
• To improve the image resolution of existing small-animal PET scanners.
• To assess the performance of the insert for preclinical imaging applications.

Main Methods:

• Constructed a full-ring PET insert with 18 high-resolution detector modules.
• Utilized cerium-doped lutetium oxyorthosilicate crystals coupled to position-sensitive photomultiplier tubes.
• Integrated the insert with an existing PET scanner for coincidence detection.
• Performed imaging studies using phantoms and mice, including gated imaging.

Main Results:

• Achieved image resolution ranging from 1.0- to 1.8-mm full width at half maximum.
• Demonstrated significant improvement in transaxial image resolution for phantoms and mouse bone imaging.
• Showcased gated imaging capability for mouse heart studies.
• Measured peak system sensitivity of approximately 2.67% and energy resolution of 19.0% +/- 3.1%.

Conclusions:

• A prototype full-ring PET insert device was successfully developed.
• The insert enhances PET image resolution within a reduced field of view for small-animal scanners.
• Further development of correction techniques is necessary for quantitative imaging.