PET
Positron Emission Tomography (Amyloid / Tau / FDG / SV2A PET)
陽電子放出断層撮影（アミロイドPET・タウPET・FDG-PET）
1. Biological & Technical Mechanism
Positron Emission Tomography (PET) measures the three-dimensional distribution of positron-emitting radiopharmaceuticals (labeled with 18F or 11C) in the living brain. Specific tracers target distinct pathological hallmarks: [18F]Florbetapir, [18F]Florbetaben, and [11C]PiB quantify fibrillar amyloid-beta plaques (standardized on the Centiloid scale); [18F]Flortaucipir and [18F]MK-6240 map neurofibrillary tau pathology across Braak stages; [18F]FDG measures regional cerebral glucose hypometabolism; and [11C]UCB-J quantifies synaptic vesicle glycoprotein 2A (SV2A) density.
陽電子放出断層撮影（PET）は、陽電子を放出する放射性同位体（18F や 11C）で標識した特異的リガンド（トレーサー）を投与し、生体脳内の分子病態を三次元的に定量するイメージング手法です。アミロイドβプラークを定量するアミロイドPET（センチロイド尺度で標準化）、神経原線維変化の広がり（Braakステージ）を可視化するタウPET、局所脳糖代謝低下を捉えるFDG-PET、さらにシナプス小胞タンパク質SV2Aを標的としてシナプス密度を直接測定するシナプスPETなどが実用化されています。
2. Open Science & Clinical Trial Significance
Amyloid and Tau PET SUVR (Standardized Uptake Value Ratio) and Centiloid metrics are primary surrogate endpoints in Alzheimer's disease clinical trials (e.g., Lecanemab, Donanemab) and are shared in BIDS-PET format on OpenNeuro and ADNI.
アミロイドPETのセンチロイド値（Centiloid）減少やタウPETのSUVR変化は、アルツハイマー病疾患修飾薬（レカネマブ、ドナネマブ等）の臨床試験においてプラーク除去確認および治療層別化のゴールドスタンダード指標として用いられており、BIDS-PET拡張規格によるオープンデータ共有も進んでいます。
Related Neuroscience Terms & Standards
Major lipid carrier in the central nervous system; the APOE ε4 allele is the strongest genetic risk factor for late-onset Alzheimer's disease.
Highly sensitive fluid biomarker reflecting both cerebral amyloid-beta plaque burden and early tau tangle phosphorylation in Alzheimer's disease.
Non-invasive neuroimaging modality measuring blood-oxygen-level-dependent (BOLD) hemodynamic signals to map brain network activity and functional connectivity.
Community ISO-aligned standard for organizing and describing neuroimaging (MRI, fMRI, dMRI, PET) and neurophysiological (EEG, MEG, iEEG) datasets.
Open Datasets & Research Publications Related to PET
Plasma p-tau217 Demonstrates High Diagnostic Accuracy in Primary Care Setting for Alzheimer’s Disease
Clinical validation indicates that the plasma p-tau217 assay achieves diagnostic accuracy comparable to Amyloid-PET and CSF analysis in primary care settings, providing an accessible biomarker for early Alzheimer’s disease detection.
OpenNeuro ds004504: Multimodal MRI & PET Repository for Early Alzheimer’s Disease and Mild Cognitive Impairment (BIDS)
An exceptional multimodal neuroimaging repository providing 3T structural MRI, resting-state fMRI, and [18F]Florbetapir Amyloid-PET scans from 180 subjects formatted strictly to BIDS standard. This open dataset serves as a benchmark resource for deep learning and diagnostic biomarker discovery in early Alzheimer's and MCI.
Hunger reconfigures a reward learning circuit into a memory competent mode
Internal states such as hunger dynamically reshape activity across circuits to support resource seeking. Neuromodulation provides a means of controlling such physiological properties of neurons, but how this flexibility regulates memory networks remains unclear. Here, we describe how hunger reconfig...
Tau-PET subtype modifies the association between plasma p-tau217 and memory in Alzheimer's disease
INTRODUCTIONPlasma p-tau217 is associated with Alzheimers disease pathology and memory performance, but its implications for memory may depend on fibrillar tau topography. We examined whether tau-PET subtype modified the association between plasma p-tau217 and memory. METHODSWe analyzed 396 amyloid...
Cumulative and Interactive Effects of Heavy Metal Mixtures Across Neurodegenerative Diseases: A Comparative Review of Alzheimer, Parkinson, Amyotrophic Lateral Sclerosis and Multiple Sclerosis.
Heavy metals and metalloids are persistent environmental contaminants that accumulate in the central nervous system and interact with endogenous essential metals, yet most neurotoxicological research continues to treat metals as independent agents rather than as co-occurring mixtures. This review systematically compares the evidence for cumulative and interactive effects of heavy metal mixtures across four major neurodegenerative diseases-Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), and multiple sclerosis (MS)-asking which metal combinations have been directly documented for each disease, and whether these patterns are disease-specific or shared. Following a PubMed search (January 2016-June 2026), 93 unique studies were included (AD: 49; PD: 38; ALS: 19; MS: 18; 31 shared across diseases). Combined exposure to lead, cadmium, arsenic, and mercury is linked to amyloid-beta accumulation and dementia risk in AD; manganese-vanadium co-exposure produces more severe dopaminergic damage in PD than either metal alone, with manganese activating the familial PD gene LRRK2; a multi-metal mixture in ALS was associated with a three-fold higher disease risk independent of genetic susceptibility; and MS showed almost no designed mixture studies despite considerable single-metal data, with conflicting findings across cohorts. Three general mechanisms were identified: competition at shared membrane transporters (notably DMT1), sequestration by metal-binding proteins, and direct synergistic or antagonistic interactions, in which essential elements can modulate toxic-metal handling. Mixture-statistics approaches (WQS, BKMR), already established for AD and PD, should be extended to MS to close this evidence gap.
Plasma p-tau217 Demonstrates High Diagnostic Accuracy in Primary Care Setting for Alzheimer’s Disease
Clinical validation study confirms that blood-based p-tau217 assay matches CSF and Amyloid-PET diagnostic precision in identifying early Alzheimer’s pathology.
Disclaimer: This encyclopedia entry is intended for academic neuroscience research and data science reference only, and does not constitute medical advice.