Background

This study investigated changes in brain perfusion and Aβ burden according to the progression of Alzheimer’s disease (AD) by using a dual-phase ¹⁸F-florbetaben (FBB) PET protocol.

Methods

Sixty subjects, including 12 with Aβ-negative normal cognition (Aβ⁻NC), 32 with Aβ-positive mild cognitive impairment (Aβ⁺MCI), and 16 with Aβ-positive AD (Aβ⁺AD), were enrolled. A dynamic PET scan was obtained in the early phase (0–10 min, eFBB) and delayed phase (90–110 min, dFBB), which were then averaged into a single frame, respectively. In addition to the averaged eFBB, an R1 parametric map was calculated from the eFBB scan based on a simplified reference tissue model (SRTM). Between-group regional and voxel-wise analyses of the images were performed. The associations between cognitive profiles and PET-derived parameters were investigated.

Results

Both the R1 and eFBB perfusion reductions in the cortical regions were not significantly different between the Aβ⁻NC and Aβ⁺MCI groups, while they were significantly reduced from the Aβ⁺MCI to Aβ⁺AD groups in regional and voxel-wise analyses. However, cortical Aβ depositions on dFBB were not significantly different between the Aβ⁺MCI and Aβ⁺AD groups. There were strong positive correlations between the R1 and eFBB images in regional and voxel-wise analyses. Both perfusion components showed significant correlations with general and specific cognitive profiles.

Conclusion

The results of this study demonstrated the feasibility of dual-phase ¹⁸F-FBB PET to evaluate different trajectories of dual biomarkers for neurodegeneration and Aβ burden over the course of AD. In addition, both eFBB and SRTM-based R1 can provide robust indices of brain perfusion.

中文翻译：

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双相 18F-florbetaben PET 提供脑灌注代理以及阿尔茨海默病中的 β-淀粉样蛋白负荷

背景

本研究使用双相¹⁸ F-florbetaben (FBB) PET 协议，根据阿尔茨海默病 (AD) 的进展调查了脑灌注和 Aβ 负荷的变化。

方法

60名受试者，包括12名Aβ阴性正常认知（Aβ ^- NC），32名Aβ阳性轻度认知障碍（Aβ ⁺ MCI）和16名Aβ阳性AD（Aβ ⁺ AD）。在早期阶段（0-10 分钟，eFBB）和延迟阶段（90-110 分钟，dFBB）获得动态 PET 扫描，然后分别平均为一个帧。除了平均 eFBB 之外，R1 参数图还根据基于简化参考组织模型 (SRTM) 的 eFBB 扫描计算得出。对图像进行组间区域和体素分析。研究了认知特征和 PET 衍生参数之间的关联。

结果

皮质区域的 R1 和 eFBB 灌注减少在 Aβ ^- NC 和 Aβ ⁺ MCI 组之间没有显着差异，而在区域和体素分析中，它们从 Aβ ⁺ MCI 到 Aβ ⁺ AD 组显着减少。然而，dFBB 上的皮质 Aβ 沉积在 Aβ ⁺ MCI 和 Aβ ⁺ AD 组之间没有显着差异。在区域和体素分析中，R1 和 eFBB 图像之间存在很强的正相关性。两种灌注成分都显示出与一般和特定认知特征的显着相关性。

结论

这项研究的结果证明了双相¹⁸ F-FBB PET 评估 AD 过程中神经变性和 Aβ 负荷的双重生物标志物的不同轨迹的可行性。此外，eFBB 和基于 SRTM 的 R1 都可以提供强大的脑灌注指数。