磁共振弥散张量成像在腰骶丛神经急性损伤诊断中应用价值

Value of DTI in the diagnosis of acute lumbosacral plexus injury

目的探讨磁共振弥散张量成像(DTI)在腰骶丛神经急性损伤诊断中的临床价值。方法选取经影像学和临床诊断为腰骶丛神经急性损伤60例为研究对象,均采用磁共振进行扫描检查,分析图像并记录相关数据。测量受损和正常L4~S1神经根各向异性分数(FA)与表观扩散系数(ADC)值。利用ROC曲线分析诊断敏感性和特异性。结果与正常神经相比,受损神经FA值明显降低(P<0.05),而ADC值明显增高(P<0.05)。ROC曲线结果显示FA值曲线下面积为0.887,阈值为0.198时,诊断腰骶丛神经损伤的敏感度为71.7%、特异度为91.7%;当FA值≤0.188时,诊断特异度为100.0%。FA值与腰骶丛神经急性损伤呈明显负相关(r=-0.647,P<0.001)。结论DTI技术应用于腰骶丛神经急性损伤诊断,具有显著效果,可较为直观地显示神经束走向和损伤具体位置,从而指导临床诊断。

Objective To investigate the clinical value of diffusion tensor imaging(DTI)to the diagnosis of acute lumbosacral plexus injury.Methods The DTI was performed in 60 patients with acute lumbosacral plexus injury who were definitely diagnozed by imaging and clinical manifestations.The values of fractional anisotropy(FA)and apparent diffusion coefficient(ADC)were measured in the normal and injured L4~S1 nerve roots.The diagnostic sensitivity and specificity were analyzed using ROC curves.Results Compared with the normal nerves,the FA value of damaged nerves decreased significantly(P<0.05),while the ADC value increased significantly(P<0.05).The ROC curve results of FA value showed that the area under curve was 0.887 and the best cutoff value was 0.198.The sensitivity and specificity of FA value to the diagnosis of lumbosacral plexus injury was 71.7%and 91.7%,respectively.When the FA value was≤0.188,the diagnostic specificity was 100.0%.FA value was negatively correlated with the acute injury of lumbosacral plexus(r=-0.647,P<0.001).Conclusion DTI,which can intuitively display the direction of nerve bundle and the specific location of injury to guide clinical diagnosis,is a good method to the diagnosis of acute injury of lumbosacral plexus.