A Novel Marker-Based Registration Method for Simultaneous Preclinical PET/MR with a Non-Stationary PET Detector

Area of Science:

• Medical Imaging
• Preclinical Research
• Biomedical Engineering

Background:

• Simultaneous PET-MRI offers synergistic insights in preclinical research.
• Registering images from small, non-stationary preclinical PET scanners to MRI is challenging.
• Existing methods struggle with limited space and detector movement.

Purpose of the Study:

• To create a fully automated, marker-based method for PET-MRI registration.
• To address registration challenges in small, non-stationary preclinical PET systems.
• To achieve sub-voxel precision in simultaneous PET-MRI.

Main Methods:

• Developed a nose cone tract with MRI-visible geometric markers.
• Utilized zero-echo-time MRI for marker visibility.
• Implemented a universal calibration and an experiment-specific calibration.
• Evaluated method robustness through systematic experiments.

Main Results:

• Achieved successful registration of PET and MRI modalities.
• Demonstrated spatial registration error below the PET voxel size.
• Validated the method's effectiveness in challenging preclinical setups.

Conclusions:

• The proposed method provides practical, sub-voxel precision PET-MRI registration.
• It is suitable for non-stationary PET devices with limited internal space.
• Enables accurate multimodal imaging in demanding preclinical applications.