A feasibility study of a PET/MRI insert detector using strip-line and waveform sampling data acquisition.

Area of Science:

• Medical Imaging
• Nuclear Instrumentation
• Biophysics

Background:

• Simultaneous Positron Emission Tomography (PET) and Magnetic Resonance Imaging (MRI) offers complementary anatomical and functional information.
• Developing compact PET detectors compatible with strong magnetic fields is crucial for integrated PET/MRI systems.
• Silicon photo-multipliers (SiPM) offer magnetic field insensitivity and fast timing, making them suitable for PET detectors.

Purpose of the Study:

• To develop and test a time-of-flight PET detector module utilizing SiPMs for simultaneous PET/MRI applications.
• To evaluate the performance of the PET detector within a high-field MRI environment.
• To assess the magnetic field interference between the PET detector and the MRI scanner.

Main Methods:

• A time-of-flight PET detector was designed using SiPMs on a strip-line with high-speed waveform sampling data acquisition.
• Multiple SiPMs were connected on a single strip-line, with signals sampled at two ends to reduce channels and determine hit position via arrival time difference.
• Prototype detector modules with 16 SiPMs coupled to LYSO scintillators were tested inside a 9.4 Tesla small animal MRI scanner.

Main Results:

• The PET detector prototype demonstrated negligible interference effects on the MRI images.
• The PET detector's performance within the MRI scanner was comparable to measurements taken outside the scanner.
• The system successfully acquired energy, time, and position information from the SiPMs.

Conclusions:

• The developed time-of-flight PET detector is feasible for integration into MRI scanners for simultaneous PET/MRI.
• The SiPM-based design effectively exploits fast timing for position determination while maintaining performance in a high magnetic field.
• This technology advances the development of compact and efficient PET insert systems for hybrid imaging.