基于体素的轻度阿尔茨海默病脑血流灌注及脑灰质结构特征

Characteristics of Cerebral Blood Flow and Cerebral Gray Matter in Patients with Mild Alzheimer's Disease Using Voxel-based Method

目的阿尔茨海默病(AD)早期诊断缺乏客观的影像学指标,本研究利用磁共振三维动脉自旋标记(3D ASL)技术和薄层三维T1加权结构成像,采用基于体素的分析方法(VBM),研究轻度AD脑血流灌注及脑灰质萎缩特征,并进行对比。资料与方法选择16例轻度AD患者(轻度AD组)和16例年龄匹配的认知功能正常者(对照组),分别进行磁共振3D ASL序列及3D T1薄层扰相梯度回波序列扫描,采用VBM对脑血流图及T1WI脑结构像进行全脑分析,比较两组患者的脑血流量(CBF)及灰质体积变化情况,并对CBF值和灰质体积进行相关分析。结果与对照组比较,轻度AD组血流灌注减低区主要在双侧楔前叶、楔叶、颞中回、颞上回、左侧海马旁回、左侧颞上极及右侧枕上回(t=3.84,P_(校正)<0.05);轻度AD患者在双侧海马、杏仁核、颞上极、左侧海马旁回及左侧颞下回灰质体积较对照组存在萎缩(t=4.12,P_(校正)<0.05);CBF与脑灰质萎缩在左侧海马旁回(r=0.50,P<0.01)及左颞上极(r=0.42,P<0.05)存在相关性。结论 VBM结合3D ASL技术能早期评价AD疾病进程中的脑萎缩和血流灌注变化,在部分重叠脑区的灌注减低区的CBF值与皮层体积减少具有相关性。

Purpose Early diagnosis of AIzheimer＇s disease is lack of objective irnaging marker. This study evaluates characteristics of cerebral blood flow （CBF） and gray matter atrophy in patients with mild Alzheimer＇s disease （AD） by using 3D arterial spin labeling （3D ASL） and thin slice 3D T1 weighted images of voxel-based method （VBM）. Materials and Methods Sixteen mild AD patients （mild AD group） and sixteen normal control subjects （control group） were recruited. 3D ASL and T1WI SPGR sequences were performed. By using voxel-based method, the whole brain CBF and T IWI images were analyzed. CBF and volume of gray matter were compared between two groups, and correlation analysis was done. Results Compared with control group, CBF hypoperfusion was detected in bilateral precuneus, cunei, middle temporal cortex, superior temporal cortex, left parahippocampal gyrus, left superior temporal pole and right superioroccipital gyrus in mild AD group （t=3.84, Pcomectod〈0.05）. Compared with control group, gray matter atrophy was found in bilateral hippocampi, amygdalae, superior temporal pole, left parahippocampal gyrus, left inferior temporal cortex in mild AD group （t=4.12, Pcorrected〈0.05）. There was a correlation in left parahippocampal gyrus and left upper pole of the temporal between changes of CBF and volume of gray matter in mild AD patients （r=0.50, P〈0.05）. Conclusion Voxel-based VBM and ASL can evaluate AD patients＇ cerebral atrophy and CBF change in early stage, and there is a correlation between changes of CBF and gray matter atrophy in some overlap areas.