脳内に異常に蓄積したタウタンパク質を捉える画像解析ソフトを開発・公開

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2026-10-02 筑波大学

筑波大学、量子科学技術研究開発機構などの研究グループは、アルツハイマー病などで脳内に異常蓄積するタウタンパク質を、PET画像から自動的かつ再現性高く解析する研究用ソフトウェア「TAME-Q」を開発し、公開した。タウに結合する放射性薬剤florzolotau(18F)を用いたPETでは、異常タウの分布を可視化できるが、従来は研究機関ごとに異なる解析プログラムや商用ソフトを使用しており、解析手順の統一や再現が難しかった。TAME-QはPETとMRIの画像を自動処理し、脳各領域の放射性薬剤の集積を示す指標を算出するほか、機械学習による「タウスコア」も計算できる。アルツハイマー病37人、進行性核上性麻痺46人、健常者50人の計133人のデータで検証した結果、先行研究と整合する解析結果が得られた。プログラムと実行環境をオープンソースで公開することで、研究者が共通手順でタウPETを解析できる基盤の構築を目指している。

脳内に異常に蓄積したタウタンパク質を捉える画像解析ソフトを開発・公開
図1.TAME-Qが実行する処理パイプラインの概観
異常なタウ蓄積を調べるPET画像(左下図)と、脳の構造を示すMRI画像(左上図)を入力として与えると、2画像の位置合わせ、半定量化の基準値の推定、脳の各部位の定量的な指標の算出を自動で行う。図はNakayama et al., BMC Medical Imaging (2026)に基づき作成。​

<関連情報>

TAME-Q: florzolotau (18F) PETの再現可能な半定量化のためのオープンソース前処理パイプライン TAME-Q: an open-source preprocessing pipeline for reproducible semi-quantification of florzolotau (18 F) PET

Kenjiro Nakayama, Kiyotaka Nemoto, Hironobu Endo, Kenji Tagai, Asaka Oyama, Miyuki Nemoto, Masashi Tamura, Miho Ota, Takahiko Tokuda, Makoto Higuchi & Tetsuaki Arai
BMC Medical Imaging  Published:09 September 2026
DOI:https://doi.org/10.1186/s12880-026-02775-5  Early provide

Abstract

Background
Florzolotau (18 F) PET can visualise tau aggregates in Alzheimer’s disease (AD) and non-AD tauopathies. A previously developed histogram-based grey-matter reference strategy enables semi-quantification without prespecifying a single anatomically spared reference region, but its reliance on in-house and proprietary tools has limited reproducibility. We developed TAME-Q, an automated, openly accessible pipeline implementing this strategy, and evaluated its technical performance and concordance with the previous workflow.

Methods
TAME-Q was applied to dynamic florzolotau PET and T1-weighted MRI from 37 participants on the AD continuum, 46 with progressive supranuclear palsy–Richardson syndrome (PSP-RS), and 50 healthy controls. The pipeline performs image alignment, tissue segmentation, Gaussian fitting of grey-matter intensity histograms, reference estimation, SUVR generation, FreeSurfer-based parcellation, extraction of 132 ROI-level SUVRs, and generation of quality-assurance outputs. Outputs were evaluated using quantitative screening and structured visual review. Disease-specific regional SUVRs and Elastic Net-derived AD-tau and PSP-tau scores were compared with a benchmark implementation. Held-out discrimination across ten 75%/25% shuffle-split iterations and post hoc reduced-feature and atlas-sensitivity analyses were also evaluated.

Results
TAME-Q completed automated preprocessing for all 133 participants, and all outputs were accepted after quality control. Bimodal and monomodal histogram fits were used in 121 and 12 participants, respectively. Age- and sex-adjusted SUVRs were higher in the inferior temporal gyrus in AD and in the globus pallidus in PSP-RS (Holm-adjusted p < 0.001). Histogram- and cerebellar-derived reference values showed broadly similar group-level scaling but differed in some individuals. TAME-Q-derived and benchmark tau scores were strongly correlated (AD-tau, r = 0.979; PSP-tau, r = 0.960). Full-cohort AUCs were 0.999 (95% CI: 0.998–1.000) for AD and 0.967 (95% CI: 0.941–0.992) for PSP; corresponding mean held-out AUCs were 0.996 ± 0.009 and 0.935 ± 0.010. Full-cohort AUCs were similar after coefficient truncation to the top 20 ROIs and after retraining with the unmerged FreeSurfer atlas.

Conclusions
TAME-Q provides an automated and inspectable implementation of histogram-based florzolotau PET semi-quantification and produced outputs concordant with the benchmark workflow in this single-center dataset. External multicenter validation is required to establish generalisability across acquisition settings and populations.

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