阿尔茨海默病与血管性痴呆脑白质损害的磁共振波谱研究

Study of proton magnetic resonance spectrum on cerebral white matter lesions in patients with Alzheimer＇s disease and vascular dementia

目的探讨氢质子磁共振波谱（1H-MRS）技术在伴有白质损害（WMLs）的阿尔茨海默病（AD）与血管性痴呆（VD）鉴别诊断中的应用价值。方法对30例伴有WMLs的AD患者、30例VD患者及30例年龄匹配健康对照者（NC）行多体素。H-MRS检查，测定受检者左侧脑室体旁白质区N-乙酰基天门冬氨酸（NAA）、肌醇（ml）、谷氨酸（Glu）及肌酸（Cr）的峰下面积，单因素方差分析比较各组间NAA／Cr、ml／Cr及Glu／Cr比值的变化。结果在左侧脑室体旁白质区，1H-MRS检查显示AD组和VD组患者NAA／Cr比值分别为（1．59±0．15）及（1．53±0．12），Glu／Cr比值分别为（0．41±0．03）及（0．49±0．04），均较NC组（1．79±0．22及0．57±0．05）明显降低，差异有统计学意义（R〈0．05）；但AD组和VD组患者之间NAA／Cr比值差异无统计学意义（P〉0．05），而两者Glu／Cr比值差异有统计学意义（P〈0．05）。AD组ml／Cr比值为0．68±0．05，较VD组（0．57±0．04）和NC组（0．55±0．03）明显升高，差异均有统计学意义（P〈0．05），而VD组ml／Cr比值较NC组差异无统计学意义（P〉0．05）。结论1H-MRS是鉴别AD与VD的有效方法之一，侧脑室体旁白质区Glu及mI的变化可能是伴有WMLs的AD患者区别于VD患者的特征性代谢变化。

Objective To evaluate the value of proton magnetic resonance spectrum （1H-MRS） in the differential diagnosis of Alzheimer＇s disease （AD） and vascular dementia （VD） patients with white matter lesions （WMLs）. Methods Multi voxel 1H-MRS were performed to 30 patients with AD,30 patients with VD, and 30 normal control volunteers. The levels of the N-acetylaspartate （NAA） , myo-inositol （mI） , glutamate （Glu） , and creatine （Cr） were measured in the white matter adjacent to the lateral ventricles. The ratios of NAA/Cr, mI/Cr and Glu/Cr were calculated and compared among the group. Comparisons of the 1 H-MRS indexes among AD, VD and NC group were conducted by one-way ANOVA. Results NAA/Cr ratios of the region of interesting in AD （1.59±0.15）and VD（1.53±0.12） group were significantly decreased compared with NC （1.79±0.22） group （P〈 0.05） , and Glu/Cr ratios of the region of interesting in AD （ 0.41±0.03 ） and VD （0.49±0.04） group were signifi- cantly decreased compared with NC（0.57±0.05） group （P〈0.05）. However, there were not significant differences for NAA/Cr ratios of the paraventricular white matter region between AD and VD group （P〉0.05） ,and Glu/Cr ra- tios in AD and VD groups were significantly different （P〈0.05）. A significantly increased mI/Cr was found in AD （ 0.68±0.05 ） group than in VD （0.57±0.04） and NC （ 0.55±0.03 ） groups （P〈0.05） , and there were no significant changes in mI/Cr ratios between VD and NC groups （P〉0.05）.Conclusion Multi-voxel 1H-MRS is an effective method in the differential diagnosis of dementia, and changes of the mI/Cr and Glu/Cr ratios of the white matter adjacent to the lateral ventricles may help to identify the AD and VD patients.