Validation of CT-free Template-Based Attenuation Correction in Brain PET Imaging

20 May 2024, 18:45
5m
La Biodola, Isola d'Elba

La Biodola, Isola d'Elba

Hotel Hermitage
Poster High-performance preclinical and organ-specific systems Poster Session

Speaker

Markus Jehl (Positrigo AG, Zurich, 8005 Switzerland)

Description

This study aims to validate a template-based attenuation correction (AC) method for clinical brain PET systems without CT, previously proposed for the new NeuroLF brain-PET. Method: The validation process involved simulating a diverse (patients/tracers) set of clinical images. This is done by transforming 142 reference PET/MR and 8 PET/CT brain images to NeuroLF image space, converting them to sinograms, then uncorrecting the sinograms for attenuation and scatter using original patient-derived attenuation maps. These uncorrected sinograms serve as a surrogate for real clinical raw data. From this, images were then re-reconstructed with both patient-specific reference and tracer-specific template attenuation maps and compared using a range of similarity metrics. Results: The stability of the template-based AC method across a diverse set of tracers for brain PET imaging could be shown. The used metrics identified cases where the MR-to-CT conversion was inadequate, but were less capable of detecting failures intentionally induced in the template map co-registration. Tracer-specific templates showed better performance than a universal (i.e. [18F]-FDG derived) template. Conclusion: The validation confirms the adequacy of the template-based AC method for clinical routine brain-PET imaging, with a recommendation for visual inspection to detect co-registration failures. We aim to further validate the template-based attenuation maps in a blinded clinical evaluation.

Field Software and quantification

Primary author

Ekaterina Mikhaylova (Positrigo AG, Zurich, 8005 Switzerland)

Co-authors

Markus Jehl (Positrigo AG, Zurich, 8005 Switzerland) Kris Thielemans (University College London) Dr Ilaria Sacco (Positrigo AG, Zurich, 8005 Switzerland) Dr Max Ahnen (Positrigo AG, Zurich, 8005 Switzerland) Dr Bernhard Sattler (University Hospital Leipzig, Department of Nuclear Medicine, Germany) Prof. Henryk Barthel (University Hospital Leipzig, Department of Nuclear Medicine, Germany) Prof. Osama Sabri (University Hospital Leipzig, Department of Nuclear Medicine, Germany) Jannis Fischer (Positrigo AG, Zurich, 8005 Switzerland)

Presentation materials