[18F]FDG administered activity reduction capabilities of a 32-cm axial field-of-view solid-state digital bismuth germanium oxide PET/CT system while maintaining EARL compliance

Abstract

Purpose

To assess the lower [¹⁸F]FDG limit in administered activity and/or scan time reduction capabilities of a digital-BGO 32-cm axial field-of-view PET system while being compliant with current and updated EANM Research Ltd Fluorine-18 accreditation specifications (EARL₁ and EARL₂).

Methods

EARL₁ and EARL₂ compliance of the digital-BGO system (Omni Legend 32 cm) was tested for several reconstructions, including those that apply precision deep learning-based image enhancement (PDL) as postprocessing, using the calibration QC and NEMA IEC phantom measurements. The image quality QC scan was repeated every hour for 7 h, with each subsequent hour representing a lower administered activity, and reconstructed for various times per bed position, i.e. 30, 60, 120, 180, and 300 s. For each of the image quality QC images, coefficient of variation (COV) of the background compartment, and mean, maximum and peak activity concentration recovery coefficients (RC_mean, RC_max and RC_peak) of differently-sized spheres were calculated and compared to current and updated EARL accreditation specifications.

Results

When we apply 1 min per bed position for PET acquisition, [¹⁸F]FDG administration can be reduced by a factor of ∼ 4 for EARL₁, by a factor of ∼ 8 for EARL₂ (2 mm voxels) and by a factor of ∼ 4 for EARL₂ (4 mm voxels) using both standard reconstructions and PDL post-processing compared to current EANM recommendations for [¹⁸F]FDG administration (7 MBqminbed^-1kg^-1).

Conclusions

Reduction in [¹⁸F]FDG administered activity is possible by at least a factor 4 for 1 min/bed with the Omni Legend 32 cm PET/CT while maintaining EARL₁ and EARL₂ compliance.