阿尔茨海默病与帕金森病痴呆病人的ASL脑灌注研究

目的 利用三维伪连续动脉自旋标记（3D pcASL）成像技术比较阿尔茨海默病（AD）和帕金森病痴呆（PDD）病人脑灌注的异同,并分析脑灌注改变与认知功能损害的相关性。 方法 前瞻性收集AD病人24例、PDD病人26例、正常对照（NC）36例,均行颅脑常规MRI及3D pcASL灌注MRI检查。采用基于Matlab的SPM12软件对3D pcASL序列扫描获得的脑血流（CBF）图进行预处理,通过单因素协方差分析及独立样本t检验进行组间比较。利用DPABI软件提取AD组与NC组、PDD组与NC组灌注存在差异脑区的相对脑血流量（rCBF）值,采用Pearson相关方法对rCBF值与简易精神状态量表（MMSE）及蒙特利尔认知评估量表（MoCA）评分做相关性分析。 结果 与NC组相比,AD组双侧大脑皮质的广泛区域灌注减低,双侧丘脑、基底节、海马及辅助运动区（SMA）灌注增高;PDD组表现为与AD组基本一致的灌注减低和增高的脑区,但是脑区变化范围缩小。与AD组相比,PDD组双侧壳核、左侧中央前回、右侧SMA灌注减低,右侧顶下小叶灌注增高。AD组左侧额中回及左侧颞中回的灌注值与MMSE评分（分别r=0.64,P<0.001;r=0.50,P=0.01）及MoCA评分（分别r=0.44,P=0.03;r=0.48,P=0.02）均呈正相关,PDD组相关脑区与认知评分未见显著相关性。 结论 3D pcASL成像技术能够直观地反映AD与PDD病人类似的脑血流灌注模式,同时显示两者的灌注差异。AD病人多个脑区灌注值与认知相关评分呈正相关,提示脑血流改变与认知损伤具有相关性。

Comparison of arterial spin labeling perfusion MRI changes in Alzheimer's disease and Parkinson's disease dementia

Objective To compare the cerebral perfusion similarities and differences between Alzheimer’s disease (AD) and Parkinson’s disease with dementia (PDD) using a three-dimensional pseudo-continuous arterial spin labeling (3D pcASL) imaging, and to test the correlations between cerebral perfusion and cognitive impairment. Methods Twenty four AD patients, 26 PDD patients, and 36 normal controls (NC) were prospectively collected. All of them underwent the conventional brain MRI and 3D pcASL perfusion MRI scanning. SPM12 software based on Matlab was used to preprocess cerebral blood flow (CBF) data obtained by 3D pcASL sequence scanning. Analysis of covariance and two-sample t test were performed to detect the difference in local cerebral perfusion among the three groups and between groups respectively. The relative cerebral blood flow (rCBF) values of brain regions with differences between AD group and NC group, and PDD group and NC group were obtained from DPABI software. The correlation between the rCBF values and MMSE and MoCA scores was analyzed with Pearson correlation method. Results Compared with the NC group, there was hypoperfusion in extensive areas of bilateral cerebral cortex in the AD group, while hyperperfusion in the bilateral symmetric regions of thalamus, basal ganglia, hippocampus, and supplementary motor area (SMA). The PDD group showed hypoperfusion and hyperperfusion in the same regions as the AD group, while the areas were lessened than the AD group. Compared with the AD group, the PDD group showed hypoperfusion in the bilateral putamen, left precentral gurus, and right SMA, whereas hyperperfusion in the right inferior marginal angular gyrus. In the AD group, the perfusion values of left middle frontal gyrus and left middle temporal gyrus were positively correlated with MMSE score (r=0.64, P<0.001; r=0.50, P=0.01, respectively) and MOCA score (r=0.44, P=0.03; r=0.48, P=0.02, respectively). No brain regions associated with cognitive assessment of cerebral perfusion were found in the PDD group. Conclusions 3D pcASL imaging can intuitively reflect that AD and PDD patients share similar cerebral blood flow perfusion patterns, and show the perfusion differences between them. The perfusion values in multiple brain regions of AD patients were positively correlated with cognitive score, suggesting the correlation between cerebral blood flow and cognitive impairment.