磁共振弥散峰度成像对急性一氧化碳中毒脑损害评估的初步研究

摘要

目的 探讨磁共振弥散峰度成像(diffusion kurtosis imaging,DKI)技术对一氧化碳(carbon monoxide,CO)中毒急性期脑组织损伤后微观结构变化的评估价值.材料与方法 对26例CO中毒急性期患者及18名健康志愿者行磁共振常规轴位T1WI、T2WI、T2WI-tirm、弥散加权成像(diffusion weighted imaging,DWI)及DKI序列扫描.分析DWI结果相关的临床影响因素,并将病例组依据DWI扫描图像中有无病灶检出分为阳性组和阴性组,分别比较两病例组与对照组各部位参数值的组间差异,同时将均存在差异部位的平均扩散系数(mean diffusion coefficient,MD)值、平均峰度(mean kurtosis,MK)值与DWI上表观扩散系数(apparent diffusion coefficient,ADC)值作相关性分析.结果 (1)意识障碍持续时间较长、早期格拉斯哥昏迷量表(glasgow coma scale,GCS)得分减低是DWI扫描结果出现阳性的影响因素;(2)与对照组相比,病例组MD值减低区位于双侧苍白球、半卵圆中心及侧脑室旁白质、胼胝体膝部;MK值升高区位于双侧苍白球、丘脑、半卵圆中心及侧脑室旁白质;其中阴、阳性两组患者苍白球同时存在MD值减低、MK值升高,丘脑同时存在MK值升高;此外,阳性组苍白球区各向异性分数(fractional anisotropy,FA)值减低;(3)病例组MD值减低、MK值升高分别与DWI的ADC值减低相关性良好.上述差异均具有统计学意义(P<0.05).结论 DKI技术可以反映CO中毒急性期患者脑组织损伤后的微结构改变,有利于从微观水平更好地理解CO中毒急性期患者脑损害的特点.%Objective: To explore the clinical value of MR diffusion kurtosis imaging (DKI) about diagnosing micro-changes of brain tissue in acute phase of CO intoxication. Materials and Methods: Routine MRI and DKI was performed in 26 cases with CO poisoning of acute stage (case group) and 18 healthy volunteers (control group). Analyze the relationships between DWI results and clinical factors. The study group was divided into two groups baesd on whether there had lesions detected in DWI images: positive and negative group. The DKI parameters of same brain area were compared separately between two case groups and control group. Analyze the correlation between ADC and two kinds of parameters of MD and MK in these differential parts of brain of case groups respectively if there were both differences in some areas. Results: ①The positive DWI scan results were affected by a long duration of disturbance of consciousness and a diminution of GCS score; ②Compared with the controls, in case groups there was a significantly reduced MD value of bilateral globus pallidus, centrum semiovale and periventricular white matter, corpus callosum genu, and MK values were increased in bilateral globus pallidus, thalamus, centrum semiovale and periventricular white matter. Thereinto, in positive and negative group, MD values of globus pallidus were significantly reduced while MKvalues were increased, and MK values of thalamus were also increased. Besides, in positive group FA values of globus pallidus were reduced; ③The results indicated that there was a strong correlation between MD or MK and ADC in case groups. The above differences were statistically significant (P<0.05). Conclusion: DKI techniques can reflect tiny structural changes of brain tissue in acute phase of CO intoxication, which will contribute to explaining features of brain damage from a micro level.