脑白质疏松症的MR扩散加权成像及波谱研究

目的通过MR扩散加权成像(DWI)及MR波谱(MRS)分析脑白质疏松症(LA)的表观扩散值(ADC)和不同代谢产物比值的变化,探讨LA中脑白质缺血过程中出现的病理、生化改变与MR功能成像改变之间的关系。方法30例经常规MRI检查诊断为LA患者,及30例年龄相匹配的正常脑白质表现的患者作为对照组,进行DWI检查,分析病变不同区域ADC值的变化,同时对LA患者进行MRS分析N-乙酰天门冬氨酸(NAA)/肌酸(Cr)、胆碱复合物(Cho)/肌酸(Cr)比值的变化,比较不同位置和不同程度病变在ADC值和代谢变化中的差异。结果LA患者病灶区(双侧侧脑室枕角、体部旁脑白质)ADC值升高与对照组差异有显著的统计学意义(P<0.01),相应病灶区的NAA/Cr均值明显降低,Cho/Cr均值升高,与正常白质比较差异有显著统计学意义(P<0.01),而枕角的NAA/Cr均值低于体部,差异有显著统计学意义(P<0.01)。结论磁共振功能成像能够反映脑白质疏松症发展中的微观结构变化和局部代谢的异常。

The study of leukoaraiosis with MR diffusion-weighted imaging and MR spectroscopy

Objective To study the combined application of MR diffusion-weighted imaging(DWI)and metabolic abnormity in proton MR spectroscopy(1HMRS)in patients with pathologic and biochemical changes of leukoaraiosis(LA).Methods DWI and 1HMRS examination were performed in 30 cases with LA to compare ADC and relative ratio values of each metabolite in different regions of lesion with normal white matter.DWI examinations were performed in 30 cases of control group with normal white matter ADC,the ratio of NAA/Cr and Cho/Cr were acquired through Function-Tool.Results The regions of lesion with LA showed the higher ADC values than the control group and there was significant difference between the both groups(P< 0.01),the ratios of NAA/Cr were lower than normal white matter but Cho/Cr were higher than normal white matter and there was significant difference in the both.Conclusion DWI and MRS can reveal the changes in micro-structure and abnormity of focal metabolite in leukoaraiosis.