基于纤维束骨架的空间统计方法研究维持性透析终末期肾病患者脑白质结构变化

Tract based spatial statistics method in exploration on changes of white matter in maintenance hemodialysis ESRD patients

目的探讨基于纤维束骨架的空间统计方法研究维持性透析终末期肾病(ESRD)患者脑白质微结构变化。方法采用3.0T MR仪对32例行维持性血透的ESRD患者和30名健康对照行DTI扫描,应用基于纤维束骨架的空间统计(TBSS)方法分析DTI多参数图,获得部分各向异性分数(FA)、平均弥散度(MD)、轴向弥散度(AD)及径向弥散度(RD)有显著差异的脑区。将ESRD患者差异脑区FA值与简易精神状态测试(MMSE)评分进行偏相关分析。结果与健康对照比较,ESRD患者双侧额叶白质、双侧前辐射冠、胼胝体体部及膝部、左侧颞叶白质及多条联络纤维FA值显著减低;MD值呈广泛且对称性显著升高;右侧上纵束、左侧上辐射冠AD值显著升高,左侧丘脑前辐射AD值显著降低;双侧额叶、胼胝体及双侧上纵束等白质区RD值显著升高(P均<0.05)。右侧额叶白质(r=0.404,P=0.022)及左侧上纵束(r=0.475,P=0.006)FA值与MMSE评分呈正相关。结论 ESRD患者脑区白质微结构受损,可能导致其认知障碍。

Objective To explore the changes of white matter in maintenance hemodialysis end-stage renal disease （ESRD） patients with tract based spatial statistics method. Methods Thirty-two ESRD patients undergoing maintenance hemodialysis and 30 healthy controls were enrolled, and underwent head diffusion tensor imaging （DTI） on a 3.0T MR scanner. By using tract based spatial statistics （TBSS） method, brain regions with significant difference in fractional anisotropy （FA）, mean diffusivity （MD）, axial diffusivity （AD） and radial diffusivity （RD） were obtained from DTI multiindex maps. Partial correlation analysis was used to explore the relationship in FA value and mini-mental state examination （MMSE） score of ESRD patients. Results Compared with the healthy control, ESRD patients showed significant de- creased FA in the bilateral frontal lobe white matter, anterior corona radiate, body and genu of corpus callosum, left temporal lobe white matter and several association fiber tracts; significant increased MD in large and symmetrical white matter regions; significant increased AD in right superior longitudinal fasciculus and left superior corona radiate, and decreased AD in left anterior thalamic radiation; significant increased RD in bilateral frontal lobe white matter, corpus callosum and bilateral superior longitudinal fasciculus （all P〈0.05）. Significant positive correlations were found between the FA values and MMSE scores in right frontal lobe white matter （r= 0.404, P= 0.022） and left superior longitudinal fasciculus （r= 0.475, P=0.006）. Conclusion The microstructural damages to white matter of functional brain regions and association fiber tracts may be responsible for cognitive impairment in ESRD patients.