The PETcoil project: PET performance evaluation of two detector modules for a second generation RF-penetrable TOF-PET...

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Biophysics

Background:

• Simultaneous Positron Emission Tomography (PET) and Magnetic Resonance Imaging (MRI) offers complementary anatomical and functional information.
• Existing PET inserts for MRI face challenges with radiofrequency (RF) interference and portability.
• A dedicated brain PET insert requires high sensitivity, spatial resolution, and temporal accuracy for optimal performance.

Purpose of the Study:

• To evaluate the performance of detector modules for a novel portable, RF-penetrable, brain-dedicated time-of-flight (TOF)-PET insert (PETcoil).
• To assess the suitability of the PETcoil design for simultaneous PET/MRI applications.
• To demonstrate the stability and scalability of the PETcoil detector modules.

Main Methods:

• Two fully assembled detector modules of the PETcoil insert were tested outside an MR environment.
• Key performance metrics including coincidence time resolution, energy resolution, count rate, and detector temperature were measured over a 2-hour period.
• Intrinsic spatial resolutions in axial and transaxial directions were determined.

Main Results:

• Excellent global coincidence time resolution of 242.2 ± 0.4 ps FWHM was achieved.
• Good global 511 keV energy resolution of 11.19% ± 0.02% FWHM was obtained.
• Intrinsic spatial resolutions of 2.74 ± 0.01 mm (axial) and 2.88 ± 0.03 mm (transaxial) FWHM were measured, alongside a coincidence count rate of 22.0 ± 0.1 kcps and stable detector temperature (23.5 ± 0.3 °C).

Conclusions:

• The PETcoil detector modules exhibit excellent time-of-flight (TOF) capability, crucial for high-resolution PET imaging.
• The demonstrated performance and stability are sufficient for constructing a full ring PET insert with 16 detector modules.
• This development paves the way for advanced, portable simultaneous PET/MRI systems for brain imaging.