Tau Burden is Best Captured by Magnitude and Extent: Tau-MaX as a Measure of Global Tau

medRxiv (Cold Spring Harbor Laboratory), Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 14, 2025

Tau exhibits change in both spatial extent and density of pathology along the Alzheimer's disease (AD) spectrum with each aspect contributing to overall burden pathological tau. Nevertheless, studies using PET have measured either magnitude standardized uptake value ratios (SUVRs) or number Tau+ regions. We hypothesized that combining these two dimensions into a single measure Magnitude eXtent, Tau-MaX, would provide improved quantification global tau as well allowing for region-agnostic does not require pre-specified region interest (ROI) meta-ROI. To test this hypothesis, we analyzed 18 F-flortaucipir scans from local national consortium data (n=1077 participants total) used Gaussian-mixture models 64 brain regions, define positivity magnitude. examined cross-sectional longitudinal Tau-MaX across compared association magnitude, plasma p-tau 217 cognition. also global, approach temporal lobe Braak stage meta-ROIs. Whereas separate assessments found earlier increases later was able dynamically capture shift demonstrating stronger preclinical clinical stages. Global differed between stages cross-sectionally changed over time all disease. Further, significantly associations cognition alone. Finally, measures performed similarly meta-ROI Tau-MaX. Together, findings indicate provides robust changes throughout course is associated blood-based biomarkers This may be particular use staging, serving an outcome monitor response therapeutic intervention.

Language: Английский

Ensemble network using oblique coronal MRI for Alzheimer’s disease diagnosis

NeuroImage, Journal Year: 2025, Volume and Issue: unknown, P. 121151 - 121151

Published: March 1, 2025

Language: Английский

Morphometry of medial temporal lobe subregions using high‐resolution T2‐weighted MRI in ADNI3: Why, how, and what's next?

Alzheimer s & Dementia, Journal Year: 2024, Volume and Issue: 20(11), P. 8113 - 8128

Published: Sept. 16, 2024

Abstract This paper for the 20th anniversary of Alzheimer's Disease Neuroimaging Initiative (ADNI) provides an overview magnetic resonance imaging (MRI) medial temporal lobe (MTL) subregions in ADNI using a dedicated high‐resolution T2‐weighted sequence. A review work that supported inclusion this modality into Phase 3 is followed by brief description MTL and analysis protocols summary studies have used these data. supplemented new study uses novel surface‐based tools to characterize neurodegeneration across biomarker‐defined AD stages. reveals pattern spreading cortical thinning associated with increasing levels tau pathology presence elevated amyloid beta, apparent epicenters transentorhinal region inferior hippocampal subfields. The concludes outlook 4. Highlights As 3, protocol includes MRI scan optimized subfields subregions. These scans are processed core obtain automatic segmentations derive morphologic measurements. More detailed granular examination response disease progression achieved applying modeling techniques. Surface‐based gray matter loss spatially expanding patterns advancing stages (AD), as defined based on positron emission tomography biomarkers accordance recently proposed criteria. closely align post mortem literature spread pathological AD, supporting role beta driver neurodegeneration.

Language: Английский