MRI在阿尔茨海默病与血管性痴呆中的鉴别价值

Value of MRI in Differential Diagnosis of Alzheimer′s Disease and Vascular Dementia

【目的】对比阿尔茨海默病(AD)和血管性痴呆(VaD)的脑区体积及脑白质高信号(WMH)差异,并探究MRI对AD与VaD的鉴别诊断价值。【方法】回顾性分析35例VaD和74例AD患者的临床资料和MRI影像资料。利用AccuBrainTM提取不同脑区及WMH的体积测量值,并利用视觉评分量表评估所有患者WMH;比较AD与VaD脑区体积及WMH差异,鉴别诊断采用主成分分析(PCA)和logistic回归模型两种方法,最后评价各指标的诊断效能。【结果】①AD组颅内总体积、脑实质、脑灰质、脑白质、海马、杏仁核、下丘脑、额叶(左、右)、枕叶(左、右)、颞叶(左、右)、顶叶(左、右)、海马(左、右)、杏仁核(左、右)、下丘脑(左、右)体积均较VaD组减小,且差异具有统计学意义(P<0.05);②深部WMH(DWMH)视觉评分在AD和VaD患者之间的差异具有统计学意义(P=0.015);并且VaD组WMH绝对与相对体积高于AD组,差异均具有统计学意义(P<0.05);③经过PCA后发现重要的参数有8个,分别为脑实质、海马、杏仁核、下丘脑、额叶(左)、枕叶(左)、颞叶(左)、顶叶(左);基于logistic回归分析,形成了包括杏仁核、WMH绝对体积和枕叶(左)组成的鉴别模型。④其中鉴别模型效能最佳,鉴别AD与VaD的敏感度为81.1%,特异度为74.3%。【结论】VaD与AD患者部分脑区体积及WMH严重程度具有显著差异。脑MRI对鉴别VD与AD具有较高的价值。

【Objective】To compare the volumes of brain regions and the white matter hyperintensities(WMH)in Alzheimer′s disease(AD)and vascular dementia(VaD)patients,and discuss values of magnetic resonance imaging(MRI)in the differential diagnosis of AD and VaD.【Methods】The clinical data and MRI images of 35 patients with VaD and 74 patients with AD were retrospectively analyzed.Volumes of different brain regions and WMH were measured by using AccuBrainTM system and visual rating scale was used to assess WMH.We then compared the volumes of brain regions and the WMH between AD and VaD.The principal component analysis(PCA)and logistic regression analysis were adopted for differential diagnosis.Receiver operating characteristic(ROC)analysis was performed to evaluate the diagnostic efficiency of the indexes.【Results】①Compared with VaD patients,AD patients showed statistically smaller volumes of total intracranial volume,brain parenchyma,gray matter,white matter,hippocampus,amygdala,hypothalamus,frontal lobe(left,right),occipital lobe(left,right),temporal lobe(left,right),parietal lobe(left,right),hippocampus(left,right),amygdala(left,right),hypothalamus(left,right)(P<0.05).②There was statistically significant differ⁃ence in the visual scores for deep WMH(DWMH)between AD and VaD patients(P=0.015).The absolute and relative volumes of WMH in VaDpatients were statistically larger than those in AD patients(P<0.05).③PCA revealed eight important parameters including brain parenchyma,hippocampus,amygdala,hypothalamus,frontal lobe(left),occip⁃ital lobe(left),temporal lobe(left)and parietal lobe(left).The identification model consisting of amygdala,occipital lobe(left)and absolute volume of WMH was established based on logistic regression analysis.④Among all the indexes,the identification model had the best diagnostic performance to differentiate AD from VaD and its sensitivity and specificity were 81.1%and 74.3%,respectively.【Conclusions】There are significant differences in both volumes of certain brain regions and severity of WMH between VaD and AD patients.The cranial MRI is of great value for the differential diagnosis of VaD and AD.