Digital PET compliance to EARL accreditation specifications

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Radiotechnology

Background:

• A novel time-of-flight positron emission tomography (TOF PET) system utilizing digital photon counting technology has been introduced.
• This system potentially offers enhanced image quality compared to traditional analog systems.

Purpose of the Study:

• To assess if the new digital TOF PET system meets the European Association of Nuclear Medicine Research Ltd (EARL) accreditation criteria.
• Specifically evaluating its suitability for fluorodeoxyglucose (FDG) PET/CT tumor imaging.

Main Methods:

• A phantom study was conducted using a NEMA NU2-2001 image quality phantom with fillable spheres.
• Data underwent ordered-subsets expectation maximization (OSEM) TOF PET reconstructions with varying voxel sizes and point spread function (PSF) modeling.
• Activity concentration recovery coefficients (RCs) were calculated and compared against EARL specifications, with and without Gaussian post-smoothing filters.

Main Results:

• Reconstructions with 4x4x4 mm³ voxels and no PSF modeling showed results closest to EARL specifications.
• Applying a Gaussian post-smoothing filter with kernel widths of 2-4 mm enabled the system to meet EARL specifications.

Conclusions:

• The digital TOF PET system, when configured with specific reconstruction parameters, successfully meets EARL accreditation standards.
• Optimal settings include OSEM reconstruction, 4x4x4 mm³ voxels, no PSF modeling, and a 2-4 mm Gaussian post-smoothing filter for FDG-PET/CT tumor imaging.