运动神经元疾病患者颈髓弥散张量成像研究

摘要

目的 研究运动神经元疾病颈髓弥散张量成像(DTI)特点,探讨DTI在运动神经元疾病中的诊断价值.方法 选取临床诊断为肌萎缩侧索硬化(ALS)患者16例、肯尼迪病(KD)患者12例及健康志愿者15名.分别行颈髓常规MRI及横断面DTI检查,测定各组C3、C5椎体水平层面颈髓前索区、后索区及舣侧皮质脊髓侧束区4个区域内感兴趣区(ROI)的表观弥散系数(apparent diffusion coefficient,ADC)和部分各向异性比值(fractional anisotropy,FA),并分析影像学参数与其病程、ALSFRS-R评分、肺功能等之间的关系.结果 ALS 组患者在C3与C5水平,前索、双侧皮质脊髓侧束的FA值较KD组、健康对照组显著降低(P<0.05),而KD组与健康对照组之间差异无统计学意义(P>0.05).3组在各不同位置的ADC值之间差异无统计学意义(P>0.05).ALS组在C3水平右侧皮质脊髓束FA值与患者ALSFRS-R评分呈正相关(r=0.52,P=0.041);各水平前索、双侧皮质脊髓束的FA值、ADC值与患者病程、肺功能之间无相关性.结论 FA值可反映颈髓皮质脊髓束的功能异常,可用于评估ALS患者上运动神经元的损伤程度,有利于运动神经元疾病的鉴别诊断.%Objective To investigate the value of MRI diffusion-tensor imaging (DTI) in the diagnosis of motor neuron disorders by studying their characteristics in the cervical spinal cord DTI.Methods Conventional MRI and axial DTI of cervical spinal cord were performed in 16 patients with amyotrophic lateral sclerosis (ALS), 12 patients with Kennedy disease (KD) and 15 healthy controls.FA and ADC values were measured in regions of interest (ROI) selected in anterior funiculus, posterior funiculus, and bilaterallateral corticospinal tracts, respectively, at the same slices (C3 and C5).In the patients with motor neuron disorders,the relations between DTI parameters and their age, duration, score of ALSFRS-R and FVC％ were analyzed.Results The FA values in the anterior funiculus and bilateral lateral corticospinal tract in ALS patients were significantly lower compared with those in the KD group and the healthy control group on both C3 and C5 levels (P＜0.05).The FA values between KD group and control group were comparable (P＞0.05).No significant differences in ADC values were present among the three groups in all different locations (P＞0.05).On C3 level,the FA values in the right corticospinal tract in ALS patients were positively correlated with ALSFRS-R scores (r= 0.52, P= 0.041 ) ; but the FA and ADC values in the anterior funiculus and bilateral lateral corticospinal tract had no correlation with the patients' duration and FVC％.Conclusions FA value reflects functional abnormality of cervical corticospinal tracts.DTI can be used for objective evaluation of upper motor neuron impairment in amyotrophic lateral sclerosis and contributes to the differential diagnosis in motor neuron disorders.