A novel partial volume correction method for accurate quantification of [(18)F] flortaucipir in the hippocampus

BACKGROUND: Off-target binding in the choroid plexus (CP) may cause spill-in of the tau PET tracer [(18)F] flortaucipir into the adjacent hippocampus region. The impact of this spill-in on hippocampal uptake was assessed using a novel partial volume correction method (PVC). METHODS: PVC was performed on 20 [(18)F] flortaucipir dynamic PET scans (10 probable AD and 10 controls). Volumes of interest (VOIs) were defined for both hippocampus and CP. The correlation between hippocampal and CP distribution volume (V(T)), with and without PVC, was determined. Both anatomically defined and eroded VOIs were used. RESULTS: For controls, the correlation between hippocampal and CP V(T) was significantly reduced after using PVC along with an eroded VOI (r(2) = 0.59, slope = 0.80 versus r(2) = 0.15, slope = 0.15; difference: p < 0.05). The same was true for AD patients (p < 0.05). CONCLUSION: PVC together with an optimized hippocampal VOI resulted in effective reduction of CP spill-in and improved accuracy of hippocampal V(T). ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s13550-018-0432-2) contains supplementary material, which is available to authorized users.