MAPT and Alzheimer disease: In a previous study, a negative correlation was reported between amyloid-PET and ASL-CBF in temporo-parietal regions across the AD continuum.10 In contrast, other studies have suggested a link between cerebrospinal fluid (CSF) biomarkers of tau, but not Aβ, with perfusion abnormalities on single photon emission computed tomography.16,17 The few available studies on the relationship between ASL-CBF and tau-PET have yielded mixed findings.