TY - JOUR T1 - The correlation of in vivo tau with amyloid beta, hypometabolism, and cortical atrophy in chronic TBI subjects. JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1484 LP - 1484 VL - 60 IS - supplement 1 AU - Davneet Minhas AU - Charles Laymon AU - Sue Beers AU - Jane Sharpless AU - Ava Puccio AU - Kathryn Edelman AU - Chester Mathis AU - David Okonkwo AU - James Mountz Y1 - 2019/05/01 UR - http://jnm.snmjournals.org/content/60/supplement_1/1484.abstract N2 - 1484Introduction: Traumatic brain injury (TBI) is associated with an earlier age of onset of Alzheimer’s disease (AD). Recent neuropathologic studies characterize post-TBI dementia as a polypathology consisting of a variety of misfolded proteins. The objective of this work was to examine the topographical distribution and severity of in vivo neurofibrillary tau and its colocalization with amyloid beta (Aβ) plaques, hypometabolism, and cortical atrophy in subjects with a history of TBI. Methods: Structural T1 magnetic resonance (MR) and [F-18]AV-1451, [C-11]PiB, and [F-18]FDG PET images were acquired in 22 subjects with a history of TBI (21-61 years old, 1 female). Each subject was classified based on their trauma exposure frequency into 3 categories: few (<4 exposures), intermediate (4-10 exposures), and numerous (>10 exposures). Structural MR images were processed with FreeSurfer v5.3 to generate 68 bilateral neocortical regions of interest (ROIs) with associated cortical thickness measures. Co-registered [F-18]AV-1451, [C-11]PiB, and [F-18]FDG PET images were sampled with FreeSurfer ROIs, and standardized uptake value ratios (SUVRs) were calculated for each radiotracer and region using FreeSurfer cerebellar grey matter as reference. [F-18]AV-1451 and [C-11]PiB SUVR images were also generated with FreeSurfer cerebellar grey matter as reference, and visually classified as positive or negative for the presence of tau and Aβ plaques. For each [F-18]AV-1451-positive and [C-11]PiB-positive subject, Pearson correlations were assessed across all ROIs between [F-18]AV-1451 SUVR and [C-11]PiB SUVR, [F-18]FDG SUVR, and cortical thickness. Results: Two subjects with numerous trauma exposures were classified as [F-18]AV-1451-positive and [C-11]PiB-positive (Case 1: 60-year old male; Case 2: 54-year old male). No other subject received positive classifications for either radiotracer. In Case 1, [F-18]AV-1451 SUVR was most prominent in occipitoparietal and occipitotemporal areas both medially and laterally (Figure 1; left cuneus: 2.36 SUVR; right cuneus: 2.42 SUVR; left lateral occipital: 2.26 SUVR; right lateral occipital: 2.29 SUVR). In Case 2, [F-18]AV-1451 SUVR was most prominent in lateral temporoparietal areas (left banks of the superior temporal sulcus: 3.15 SUVR; right banks of the superior temporal sulcus: 3.07 SUVR; left precuneus: 2.83 SUVR; right precuneus: 3.11 SUVR; left parietal: 2.82 SUVR; right parietal: 2.90 SUVR). In both cases, increased regional [F-18]AV-1451 SUVR was not significantly correlated with [C-11]PiB SUVR but was significantly correlated with decreased [F-18]FDG SUVR and decreased cortical thickness (Figure 2). Conclusion: The topography and severity of [F-18]AV-1451 uptake, [C-11]PiB uptake, [F-18]FDG hypometabolism, and cortical atrophy seen in these cases is consistent with patterns previously reported in typical and atypical variants of AD, including posterior cortical atrophy. Notably, the distribution of [F-18]AV-1451 uptake observed in these cases is topographically associated with hypometabolism and cortical atrophy, but is not associated with [C-11]PiB uptake. ER -