早期相11C-PIB PET显像探讨阿尔茨海默病患者脑功能网络改变

目的 探讨阿尔茨海默病（AD）和轻度认知功能障碍（MCI）患者¹¹C-匹兹堡化合物（¹¹C-pPIB）脑灌注网络改变。方法 对14例AD（AD组）、12例MCI（MCI组）和14名认知功能正常志愿者（对照组）行¹⁸F-FDG及¹¹C-PIB双示踪剂PET显像，采用平行独立成分分析法（pICA）计算¹¹C-pPIB和¹⁸F-FDG数据中高度相关的脑网络，以双样本t检验比较AD组与对照组间和MCI组与对照组间¹⁸F-FDG低代谢与¹¹C-pPIB低灌注的差异，获得组间有差异的脑区。结果 ¹¹C-pPIB获得的脑灌注网络与¹⁸F-FDG代谢网络高度相关（r=0.92），并与默认网络（DMN）存在空间重叠。与对照组比较，AD组¹⁸F-FDG低代谢区与¹¹C-pPIB低灌注区存在空间重叠，包括颞上回、边缘叶/海马旁回、顶上小叶、后扣带回和前扣带回；MCI组¹⁸F-FDG的低代谢脑区位于右侧直回/眶额回、左侧后扣带回、右侧颞下回和右侧顶下小叶/颞上回，¹¹C-pPIB低灌注脑区为右侧顶下小叶。结论 AD患者¹¹C-pPIB低灌注脑区与¹⁸F-FDG低代谢高度相关，并与DMN存在空间重叠。¹¹C-pPIB显像可为诊断AD提供与¹⁸F-FDG显像互补的信息。

Early-phase 11C-PIB PET imaging in identifying brain network alterations in Alzheimer disease

Objective To observe the brain network changes in patients with Alzheimer disease (AD) and mild cognitively impaired (MCI) using early-phase ¹¹C-PIB (Pittsburgh compound B, pPIB) PET scan. Methods A total of 14 patients with AD (AD group), 12 patients with MCI (MCI group) and 12 healthy controls (control group) underwent ¹¹C-PIB and ¹⁸F-FDG PET/CT scaning. The parallel independent component analysis (pICA) was used to calculate strong correlated brain networks between AD and MCI patients. The differences of hypometabolic FDG and low perfusion ¹¹C-pPIB areas were compared among AD, MCI and control groups with two-sample t-test. Results The brain perfusion network derived from ¹¹C-pPIB PET was strongly correlated with brain metabolic network derived from ¹⁸F-FDG PET (r=0.92), both co-localized with the default mode network (DMN). Particularly, compared with control group, a decreased ¹⁸F-FDG uptake was shown to correlate with a lower regional perfusion of ¹¹C-pPIB in superior temporal gyrus, limbic lobe/parahippocampal gyrus, superior parietal lobule, anterior cingulate cortex and posterior cingulate cortex in AD group; in MCI group, ¹⁸F-FDG uptake decreased in the right rectal gyrus/orbit frontal cortex, left posterior cingulate cortex, right inferior temporal gyrus and right inferior parietal lobule/superior temporal gyrus, while hypoperfusion of ¹¹C-pPIB was only detected in the right inferior parietal lobule. Conclusion There is strong relationship between hypometabolic ¹⁸F-FDG and low perfusion ¹¹C-pPIB areas in AD patients, both co-localized with the DMN. ¹¹C-pPIB can provide complementary information for ¹⁸F-FDG examination in AD.