MAPT and Alzheimer disease: When applying the temporo-orbital WM reference to the disease controls, we detected cortical temporo-parietal SUVr increases in AD vs. HC, while only minor group differences were detected for α-syn vs. HC groups in meningeal regions, confirming the specificity of the temporo-orbital WM reference region as per tau positive (i.e. AD) and negative (i.e., α-syn) disease controls.