CenTauR: Toward a universal scale and masks for standardizing tau imaging studies

Abstract

INTRODUCTIONRecently, an increasing number of tau tracers have become available. There is a need to standardize quantitative tau measures across tracers, supporting a universal scale. We developed several cortical tau masks and applied them to generate a tau imaging universal scale.METHODOne thousand forty‐five participants underwent tau scans with either 18F‐flortaucipir, 18F‐MK6240, 18F‐PI2620, 18F‐PM‐PBB3, 18F‐GTP1, or 18F‐RO948. The universal mask was generated from cognitively unimpaired amyloid beta (Aβ)− subjects and Alzheimer's disease (AD) patients with Aβ+. Four additional regional cortical masks were defined within the constraints of the universal mask. A universal scale, the CenTauRz, was constructed.RESULTSNone of the regions known to display off‐target signal were included in the masks. The CenTauRz allows robust discrimination between low and high levels of tau deposits.DISCUSSIONWe constructed several tau‐specific cortical masks for the AD continuum and a universal standard scale designed to capture the location and degree of abnormality that can be applied across tracers and across centers. The masks are freely available at https://www.gaain.org/centaur‐project.

Prediction of future cognitive decline among cognitively unimpaired individuals using measures of soluble phosphorylated tau or tau tangle pathology

“…This includes, among other factors, determining the criteria for "high/positive" vs "low/negative" for both plasma p-tau217 and Tau-PET, deciding whether to use p-tau217 alone or in combination with other plasma biomarkers (e.g., Ab42/40), identifying the target regionof-interest for Tau-PET quantification and selecting a quantitative threshold and/or visual read metric for Tau-PET. 36,37 The main strength of this study is the multicenter approach that yielded a sufficient sample size for a robust head-to-head comparison between Tau-PET and plasma p-tau217 as well as a thorough assessment of their potential complementary value. The main limitations of the study are related to the inherent challenges of a multi-center study that was not co-designed from the start.…”

Alzheimer’s Disease biological PET staging using plasma p217+tau

“…For tau PET uptake in the moderate SUVR range in the Te ROI, we considered values between 1.24 and 2.68. The upper threshold of 2.68 Te SUVR corresponds to 80 CenTauR 19, 20 . We considered 80 CenTauR as a cut-off point between low/medium (or intermediate) and high tau burden, as we calculated that this approximates the threshold used for tau PET staging (intermediate vs .…”

Head-to-head comparison of leading blood tests for Alzheimer's disease pathology

“…The four 5-minute flortaucipir PET scans were corrected for motion, averaged, smoothed to a uniform resolution of 6 mm, and co-registered to the individual participant’s accompanying T1-weighted MRI scan. Using the CenTauR standardized masks [29], SUVRs were estimated for regions of interest (ROIs) as defined by FreeSurfer v7.1. The mesial temporal meta-ROI included regions with early tau PET signal (entorhinal, parahippocampus and amygdala), and the temporal-parietal meta-ROI included regions with both early and later tau PET signal (the entorhinal, parahippocampus, amygdala, fusiform, inferior and middle temporal gyri).…”