Fig. 2.

Heterogeneous patterns of FTP binding in the A-T+ group. Each image consists of an MRI (grayscale) with the co-registered PET image overlaid. The images represent Negative or false-positive pattern (A), bilateral medial temporal binding pattern (B) or AD-like pattern (C, D), and atypical (E) or non-AD pattern (F, G). The right hemisphere is displayed on the right side. (A) No significant cortical binding on visual assessment. Likely false-positive quantification due to partial volume effect in the inferior temporal lobe, high off-target signal in the base of the skull, and non-specific signal in the white matter (68/female, MCI, MMSE 28). (B) Mild bilateral medial temporal FTP binding which could reflect PART (61/male, dementia, MMSE 23), (C) Mild bilateral medial and lateral temporal tracer retention which could represent PART or early AD (86/male, MCI, MMSE 28). (D) Mild lateral temporal, parietal, and frontal tracer retention in a pattern suggestive of AD (75/male, Normal, MMSE 26), (E) Intense asymmetric left-dominant parieto-temporal binding, highly suggestive of lvPPA due to AD despite amyloid negativity (71/male, Normal, MMSE 29), and (F) Intense binding in bilateral temporal poles, suggestive of MAPT mutation (68/male, MCI, MMSE 23) and (G) Mild to moderate tracer binding predominantly in the frontal white matter, suggestive of non-AD pathology (possible primary tauopathy) (68/male, MCI, MMSE 29). Abbreviations: AD, Alzheimer’s disease; FTP, ¹⁸F-flortaucipir; lvPPA, logopenic variant primary progressive aphasia; MAPT, microtubule-associated protein tau MCI, mild cognitive impairment; MMSE, mini-mental state examination; PART, primary age-related tauopathy.