阿尔茨海默病与血管性痴呆的^(18)F-FDG PET显像特点

The characteristics of PET scan in the Alzheimer disease and vascular dementia

目的采用功能性成像正电子发射断层显像(positron emission computed tomography,PET)检测阿尔茨海默病(Alzheimer Disease,AD)和血管性痴呆(vascular dementia,VD)患者的脑葡萄糖代谢,以了解AD和VD患者脑代谢改变的异同,以寻求AD早期诊断与鉴别的方法。方法收集AD和VD患者及年龄匹配的正常对照者的相关资料,用PET技术检测入选对象脑对18氟标记的脱氧葡萄糖(18F-2-fluoro-deoxy-D-glucose,18F-FDG)的摄取,将各脑区的平均标准化摄取值(the average standard uptake value,SUV)分别与同侧小脑的SUV比较,用此比值作为评价脑局部葡萄糖代谢率的半定量指标。结果 PET结果统计分析显示:AD组右侧顶叶小脑比值、顶颞后区小脑比值、额叶小脑比值、海马小脑比值、颞叶小脑比值以及双侧扣带后回小脑比值低于VD组,具有统计学差异(P≤0.01);AD组双侧扣带后回小脑比值、顶颞后区小脑比值、额叶小脑比值、颞叶小脑比值均比NC组减少,具有统计学差异(P≤0.01);VD组右顶叶小脑比值、右扣带后回小脑比值、右海马小脑比值比NC组增加,差异有统计学意义(P≤0.01),VD组左侧顶颞后区小脑比值、左丘脑小脑比值、左额叶小脑比值比NC组减少,差异具有统计学意义(P≤0.01)。结论 AD患者18F-FDG-PET具有一定特点,对其早期诊断及鉴别诊断有一定诊断价值。

Objective To investigate early and differential diagnosis of Alzheimer disease and vascular dementia （VD）using FDG-PET scan. Methods Clinical data was collected from AD,VD and normal control（NC）. 18F-2-fluo-ro-deoxy-D-glucose（18F-FDG）PET scan was conducted to detect the cerebral FDG metabolism. The average standard uptake value （SUV） of cerebral regions was expressed as semiquantitative index relative to ipsilateral cerebellum. Re-sults There were no differences in age and the mean total scores of the mini mental status examination （MMSE） between patients with VD and those with AD.The AD group showed that the SUV was significantly decreased in the right frontal, parietal,temporal lobe,hippocampus,temporo-parietal junction,and bilateral posterior cingulate cortex compared to the VD and in the bilateral posterior cingulate cortex,temporo-parietal junction,frontal and temporal lobe comparing to the NC（P≤0.01）. SUV was significantly increased in the right parietal,posterior cingulate cortex and hippocampus whereas was significantly decreased in the left frontal lobe,temporo-parietal junction and thalamus in the VD compared with NC group（P≤0.01）. Conclusion AD patients have typical features of 18F-FDG PET which may be helpful for the diagnosis of AD in the early stage.