In Q4 2021 EARL initiated ¹⁸F / ¹¹C Brain PET/CT accreditation. It is based on a pilot study published by Verwer et. al.¹  In addition to already active and in good standing either ¹⁸F  standards 1 or 2 accreditation, for the ¹⁸F/¹¹C Brain PET/CT accreditation Hoffman 3D Brain phantom images are required to be submitted once per year. This phantom simulates brain uptake of radiopharmaceuticals with a grey matter to white matter ratio (GMWMr) of 4. The limits of acceptability for the Brain PET/CT  accreditation can be reviewed under Accreditation Specifications.

As discussed in the referenced publication, marked differences were found between reconstructions with resolution modeling (PSF_ON) and those without PSF modeling (PSF_OFF). Therefore, separate harmonisation criteria were defined for PSF_ON and PSF_OFF. 

Since currently the majority of clinical brain PET scans are reconstructed without PSF (because of the Gibbs artefacts PSF can introduce), the EARL accreditation will focus on PSF_OFF reconstructions. 

However, we did find that the differences between systems are smaller for PSF_ON reconstruction (i.e. better harmonisation can be achieved). We will therefore, continue to study the possibilities of harmonisation for PSF_ON reconstructions and invite sites to (on a voluntary basis) upload PSF_ON data in addition to the PSF_OFF data that is used for accreditation.