18F-FDG PET/CT脑显像评价认知障碍患者中的脑小血管病变对皮层功能的影响

目的 探讨18氟代脱氧葡萄糖（18F-fluorodeoxyglucose，18F-FDG）正电子发射断层成像/计算机断层扫
描（positron emission tomography/computed tomography，PET/CT）脑显像评价认知障碍患者中的脑小血
管病变对皮层功能的影响。
方法 本研究为回顾性研究，纳入2009年1月～2010年12月北京协和医院PET中心行18F-FDG PET/CT
脑显像且颅脑磁共振成像（magnetic resonance imaging，MRI）提示存在小血管病变的认知障碍患者21例，
其中临床诊断血管性痴呆（vascular dementia，VaD）10例，阿尔茨海默病（Alzheimer’s disease，AD）或混
合型痴呆（mixed dementia，MD）11例。首先目测两组患者的18F-FDG PET/CT脑显像皮层及皮层下核团代
谢减低特点，并结合颅脑MRI判断病变血管对脑代谢的影响。使用NeuroQ软件和Scenium软件对18F-FDG
PET/CT脑图像在像素基础上进行定量分析比较两组患者的皮层代谢情况。
结果 通过目测和NeuroQ软件分析发现VaD组患者18F-FDG PET/CT脑显像图像特点为无规律，不对
称皮层或皮层下核团代谢减低，其中额叶皮层代谢减低范围最广，程度最重。结合颅脑MRI改变，考
虑皮层和皮层下核团代谢减低主要为小血管病变引起。AD或MD组患者脑代谢均呈现双侧颞顶叶代谢
减低，其中8例出现皮层代谢减低不对称表现，6例出现基底节丘脑不对称代谢减低表现，与典型AD
的表现不符，结合颅脑MRI表现，考虑为病变血管所致，小血管病变可能导致相应皮层代谢减低。通
过定量分析发现两组患者的SUV比值在左右顶叶、内外颞叶和枕叶差异具有显著性。
结论 18F-FDG PET/CT脑显像作为功能影像可以推断小血管病变与皮层及皮层下核团代谢的关系。

Evaluating the Relationship of Cerebral Microangiopathy and Cerebral Glucose Metabolism with 18F-FDG PET/CT Brain Imaging in Cognitive Impairment Patients

Objective To explore the relationship of cerebral microangiopathy and cerebral glucose
metabolism with 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed
tomography (PET/CT) brain imaging in cognitive impairment patients.
Methods Twenty-one patients with cerebral microangiopathy who complained of congnitive
impairment were performed 18F-FDG PET/CT brain imaging. Brain hypometabolic patterns of
PET images were visually analyzed and the contributions of cerebral microangiopathy to cortical
metabolism were evaluated. For the group of vascular dementia (VaD), the most decreased FDG
uptake regions of PET images were identified by comparing to normal control with NeuroQ
software. The brains areas were automatically outlined by Scenium software and the mean SUV
was calculated in 21 patients.
Results No specific hypometabolic pattern was found in VaD group. The asymmetric, cortical and
subcortical hypometabolic regions were found predominantly in frontal lobe by NeuroQ analysis,
which were supposed to be due to cerebral microangiopathy and might contribute to the congnitive
dysfunction. Typical hypometabolic patterns involved in bilateral temporal and parietal lobe were
found in 18F-FDG PET/CT brain images of Alzheimer's disease (AD) (or mixed dementia MD])group. Atypical asymmetric cortical and subcortical hypometabolic regions were presented in 8
patients, subcortical hypometabolic regions was found in 6 paitents, which were supposed to be due
to cerebral microangiopathy. There were significant statistical differences in the mean SUV ratio of
bilateral temporal lobe, occipital lobe and parietal lobe between two groups.
Conclusion 18F-FDG PET/CT brain imaging might be a potential biomarker to evaluate the
contribution of cerebral microangiopathy to cortical and subcortical metabolism.