Figure 1.

Representative¹¹ C-PBB3 SUVR PET images of AD patients with low (A) and high (B) AS scores. High radioligand retention in the superior sagittal sinus (yellow triangles in panels a and b) is a non-specific radioactivity accumulation. AD patient with high AS score showed remarkably increased radioligand retention in the vicinity of OFC (yellow arrows in panel b) relative to the patient with low AS score (A). Statistical parametric map illustrates greater accumulations of PBB3-detectable tau lesions in OFC in AD patients with high AS scores relative to those with low AS scores (C). Data are thresholded at false discovery rate-corrected p value <0.05 and extent threshold >600 voxels (C). ¹¹ C-PBB3, ¹¹C-pyridinyl-butadienyl-benzothiazole 3; AD, Alzheimer’s disease; AS, Apathy Scale; OFC, orbitofrontal cortex; PET, positron emission tomography; SUVR, standardised uptake value ratio.