Abstract: Objective To assess the diffusion changes of normal-appearing spinal cord (NASC) in patients with multiple sclerosis (MS). Methods Axial diffusion tensor imaging (DTI) of the cervical spinal cord was performed in 13 patients with MS and 13 sex- and age-matched healthy controls. Fractional anisotropy (FA) and mean diffusivity (MD) measurements were made in the spinal cord at the C2-5 level. Regions of interest (ROIs) were placed in the anterior, lateral, posterior spinal cord, and the central spinal cord. Expanded Disability Status Scale (EDSS) scores were investigated. Study t-test and Pearman correlation were performed. Results Compared with healthy controls, FA in NASC of patients with MS was significantly decreased in several regions including the left anterior (mean ± SD of 0.44 ± 0.06 versus 0.48 ± 0.04 in control subjects, P = 0.000), right anterior (0.42 ± 0.06 versus 0.48 ± 0.04, P = 0.000), left lateral (0.48 ± 0.06 versus 0.51 ± 0.01, P = 0.001), right lateral (0.49 ± 0.06 versus 0.51 ± 0.03, P = 0.007), and left posterior (0.48 ± 0.06 versus 0.51 ± 0.03, P = 0.002), right posterior (0.48±0.06 versus 0.50 ± 0.03, P = 0.007). Negative correlation was observed between FA reduction with EDSS scores (r = -0.328- -0.207, P = 0.001-0.035). Positive correlation was seen between MD with EDSS scores in ROIs (r = 0.234-0.409, P = 0.000-0.018). Conclusion NASC diffusion abnormalities were found in patients with MS. The association between FA in NASC and EDSS suggests FA may be a potentially quantitative biomarker for monitoring clinical severity of MS with latent lesion.

Key words: Diffusion magnetic resonance imaging, Multiple sclerosis, Spinal cord diseases, Cervical vertebrae

摘要： 目的  通过扩散张量成像研究多发性硬化患者常规MRI表现正常脊髓（NASC）的改变，并探讨其临床应用价值。方法  采用平面回波成像技术对13 例多发性硬化患者和13 例健康志愿者施行颈髓扩散张量成像检查，分别测量第2 ~ 5 颈椎（C2 ~ 5）水平前索、后索、侧索及灰质兴趣区的部分各向异性（FA）值及平均扩散率（MD）值，比较两组之间所存在的差异性；相关分析检验多发性硬化组患者FA值和MD 值与扩展残疾状态量表（EDSS）评分之间的关系。结果  与正常对照组相比，多发性硬化组患者C2 ~ 5 前索、侧索、后索和灰质NASC 的FA 值降低、MD 值升高（均P < 0.05）；相关分析显示，FA 值与EDSS 评分呈负相关（r =-0.328 ~ -0.207，P = 0.001 ~ 0.035），各兴趣区MD 值与EDSS 评分呈正相关（r =0.234 ~ 0.409，P = 0.000 ~ 0.018）。结论  多发性硬化患者常规MRI 表现比正常脊髓的FA 值降低，提示存在隐匿性病变。脊髓扩散张量成像对多发性硬化患者临床评价和疗效判断有一定应用价值。

关键词: 磁共振成像, 弥散, 多发性硬化, 脊髓疾病, 颈椎