LAUSR

the CBD patient compared to the HC cohort are summarized in Table 1. Although most ROIs contained SUVRs greater than 1.0, z-scores were not significantly different from the mean score of our HC cohort, with the exception of the insula. Our results are consistent with postmortem data reporting that [F]AV-1451 binds preferentially to PHF tau, found in AD, over the straight filaments of tau that accumulate in nonAD tauopathies, such as CBD. Other clinical studies have also indicated overlap of [F]AV-1451 uptake in non-AD tauopathies and healthy controls. In one case study, [F] AV-1451 SUVR in a CBD patient was correlated with tau accumulation at autopsy; however, autoradiographic results indicated that [F]AV-1451 bound 4R-tau to a very low degree. Limitations of our study include using the corpus callosum as a reference region attributed to the presence of tau in the cerebellum and an elevated variance in the control group. Together with the inconsistent findings from past postmortem studies, our results demonstrate that [F]AV-1451 is not an appropriate radiotracer for non-AD tauopathies.