Abstract: Objective To investigate the presence of damage to the normal-appearing thalamus in relapsing-remitting multiple sclerosis (RRMS) and the relationship of diffusion tensor imaging (DTI) with the degree of disability of patients with RRMS. Methods Conventional MRI and DTI were acquired in 24 patients with relapsing -remitting MS and 24 age - and sex - matched healthy volunteers. DTI parameters including fractional anisotropy (FA) and mean diffusivity (MD) were measured in normal-appearing thalamus by application areas of interest method. Group differences in MD and FA were examined and correlations between DTI parameters and clinical score of patients or lesion volume were investigated. Results Patients with RRMS had lower thalamic MD [(85.34 ± 14.68) × 10-3 mm2/s] than volunteers [(98.42 ± 13.10) × 10-3 mm2/s, t = - 3.257, P = 0.002], and higher FA (0.40 ± 0.04) than volunteers (0.36 ± 0.05, t = 3.163, P = 0.003). In patients with RRMS, MD values correlated with the Paced Auditory Serial Addition Test (PASAT) scores (r = 0.711, P = 0.000). Conclusion DTI was sensitive to detect abnormalities in normal-appearing thalamus of patients with RRMS. The association between thalamic DTI indexes and functional impairment suggests DTI is a promising marker of the RRMS for future studies.

Key words: Multiple sclerosis, relapsing-remitting, Diffusion magnetic resonance imaging, Thalamus

摘要： 目的 通过扩散张量成像研究复发-缓解型多发性硬化患者常规MRI 表现正常的丘脑扩散参数异常，以及与临床残疾程度和认知损害间的相关性。方法 24 例复发-缓解型多发性硬化患者和与之性别、年龄相匹配的健康志愿者分别接受常规MRI和扩散张量成像检查，利用兴趣区法测量影像正常的丘脑扩散参数，比较两组受试者丘脑平均扩散率和部分各向异性间的差异性，并评价患者丘脑扩散参数与临床相关评分及病灶体积之间的相关关系。结果 复发-缓解型多发性硬化组患者丘脑平均扩散率［（85.34 ± 14.68）× 10-3 mm2/s］低于正常对照组［（98.42 ± 13.10）× 10-3 mm2/s］，组间差异具有统计学意义（t = - 3.257，P = 0.002）；丘脑部分各向异性（0.40 ± 0.04）高于正常对照组（0.36 ± 0.05），差异亦有统计学意义（t = 3.163，P = 0.003）。复发-缓解型多发性硬化组患者丘脑平均扩散率与同步听觉连续加法测验评分呈显著正相关（r = 0.711，P = 0.000）。结论 对常规MRI 表现正常的复发-缓解型多发性硬化患者，扩散张量成像可以发现丘脑异常。而且丘脑扩散异常与患者认知损害存在相关性，提示扩散张量成像作为评价临床功能的重要指标，具有很好的应用前景。

关键词: 多发性硬化, 复发缓解性, 磁共振成像, 弥散, 丘脑