In Alzheimer’s Disease (AD) dual-tracer positron emission tomography (PET) studies with 2-[¹⁸F]-fluoro-2-deoxy-D-glucose (FDG) and ¹¹C-labelled Pittsburgh Compound B (PIB) are used to assess metabolism and cerebral amyloid-β deposition, respectively. Regional cerebral metabolism and blood flow (rCBF) are closely coupled, both providing an index for neuronal function. The present study compared PIB-derived rCBF, estimated by the ratio of tracer influx in target regions relative to reference region (R₁) and early-stage PIB uptake (ePIB), to FDG scans. Fifteen PIB positive (+) patients and fifteen PIB negative (-) subjects underwent both FDG and PIB PET scans to assess the use of R₁ and ePIB as a surrogate for FDG. First, subjects were classified based on visual inspection of the PIB PET images. Then, discriminative performance (PIB+ versus PIB-) of rCBF methods were compared to normalized regional FDG uptake. Strong positive correlations were found between analyses, suggesting that PIB-derived rCBF provides information that is closely related to what can be seen on FDG scans. Yet group related differences between method’s distributions were seen as well. Also, a better correlation with FDG was found for R₁ than for ePIB. Further studies are needed to validate the use of R₁ as an alternative for FDG studies in clinical applications.

在阿尔茨海默病 (AD) 中，使用 2-[ ¹⁸ F]-氟-2-脱氧-D-葡萄糖 (FDG) 和¹¹ C 标记的匹兹堡化合物 B (PIB) 进行双示踪剂正电子发射断层扫描 (PET) 研究，分别评估代谢和脑淀粉样蛋白-β沉积。区域脑代谢和血流量（rCBF）密切相关，两者都提供神经元功能的指标。本研究将 PIB 衍生的 rCBF（通过目标区域相对于参考区域的示踪剂流入比率 ( R ₁ ) 和早期 PIB 摄取 (ePIB) 来估计）与 FDG 扫描进行了比较。 15 名 PIB 阳性 (+) 患者和 15 名 PIB 阴性 (-) 受试者接受了 FDG 和 PIB PET 扫描，以评估R ₁和 ePIB 作为 FDG 替代品的使用情况。首先，根据 PIB PET 图像的目视检查对受试者进行分类。然后，将 rCBF 方法的判别性能（PIB+ 与 PIB-）与标准化区域 FDG 摄取进行比较。分析之间发现了很强的正相关性，这表明 PIB 衍生的 rCBF 提供的信息与 FDG 扫描中看到的信息密切相关。然而，方法分布之间也存在与组相关的差异。此外， R ₁与 FDG 的相关性优于 ePIB。需要进一步的研究来验证R ₁在临床应用中作为 FDG 研究替代品的用途。