アミロイドPET（18F-florbetapir）における定量指標の検討

Evaluation of quantitative indicators in amyloid PET（18F-florbetapir）

近年，超高齢社会を迎えている我が国において，認知症患者の増加が社会問題化している。認知症高齢者の推定は，2012年に462万人，2025年には675万人～730万人と，およそ5人に1人が認知症となることが，2017年版高齢者白書，厚生労働省などにより公表されている^1）。

This study determined the optimal quantitative threshold for positive images in amyloid PET scans, assessed the utility of Centiloid scale in mild cognitive impairment（MCI）for clinical diagnosis, and established the corresponding determination thresholds. The visual assessment cut-off value was 21.97. The MCI cut-off was 13.45, lower than the value of 17.0 typically considered positive by highly experienced readers of amyloid PET. Furthermore, it was sufficiently lower than 26, which highly correlates with positive visual assessment, and also indicated the possibility of MCI even when the visual assessment was negative. Based on these findings, it is considered highly useful for diagnostic assistance, even in cases where visual judgment is uncertain.