基于弥散张量成像的终末期肾病脑白质结构异常与认知功能障碍相关性分析

目的 探讨终末期肾病（ESRD）患者脑白质结构异常与认知损伤的相关性。方法 对26例ESRD患者（ESRD组）和25名健康志愿者（HC组）进行蒙特利尔认知量表（MoCA）评估，并比较两组受试者整体认知评分和子项评分的差异；采用基于DTI的纤维束骨架的空间统计分析（TBSS）方法获得各向异性分数（FA）、平均扩散系数（MD）、轴向扩散系数（AD）及平行扩散系数（RD）；将ESRD组MoCA得分与有差异脑区FA值进行基于体素的Spearman相关分析。结果 ESRD组与HC组比较，MoCA总分和MoCA子项包括视觉空间与执行能力、语言和延迟回忆差异有统计学意义（P均<0.05）；ESRD组双侧下额枕束、辐射冠、上纵束、穹窿、丘脑后辐射、大脑脚，右侧内囊及外囊，脑桥，胼胝体膝部和体部FA值减低（P均<0.05）；ESRD组双侧大脑白质对称MD、AD、RD升高（P均<0.05）。ESRD组右侧外囊FA值与MOCA得分呈正相关（r=0.61，P<0.05）。结论 终末期肾病存在包括记忆、执行力等领域认知损伤，且与脑白质纤维束异常存在一定相关性；右侧外囊区的FA值减低与认知损伤密切相关，可为ESRD患者在血液透析过程中脑结构-功能损伤研究提供新的诊断学标记。

Diffusion tensor imaging based white matter abnormity and cognitive impairment in end-stage renal disease patients: Correlation analysis

Objective To investigate the correlation of cognitive impairment and white matter structural abnormity in end-stage renal disease (ESRD) patients. Methods Twenty-six ESRD patients (ESRD group) and 25 healthy controls (HC group) were assessed with Montreal Cognitive Assessment (MoCA). Based on tract based spatial statistics (TBSS), the DTI quantitative indicators, fractional anisotropy (FA), mean diffusivity (MD), parallel to the axial diffusivity (AD) and radial diffusivity (RD), were obtained. Voxel-based Spearman correlation analysis were performed to analyze the MoCA scores of ESRD group with FA value. Results Compared with HC group, the total MoCA scores and sub-MoCA scores including visuospatial and executive, language and delayed recall were all decreased in ESRD group (all P<0.05). FA in ESRD group significant decreased in the bilateral inferior frontal occipital fasciculus, corona radiate, superior longitudinal fasciculus, fornix, posterior thalamic radiation, cerebral peduncle, right internal capsule and external capsule, pons, genu and body of the corpus callosum (all P<0.05). MD, AD and RD value in ESRD group increased in the bilateral symmetry brain white matter (all P<0.05). FA value in the right external capsule of ESRD group had significant positive correlation with MoCA scores (r=0.61, P<0.05). Conclusion Cognitive impairment, which includes the faculty of memory and capacity of execution, can be caused by ESRD. Cognitive impairment is correlated with the abnormal changes of brain white matter fiber tracts. The FA value reduction in the right external capsule is closely related to cognitive impairment, which may provides a new imaging marker of brain structure and function for ESRD patients under hemodialysis.