急性创伤后早期脑结构网络小世界属性的磁共振研究

Small⁃world Characteristics in Brain Structural Network Shortly After Acute Stress:A MRI Study

目的:采用基于磁共振弥散张量成像(DTI)的图论方法探讨急性创伤后早期脑结构网络拓扑属性,分析小世界属性的变化及其意义。方法:收集交通事故受害者31例作为创伤组,纳入同一时间段在社区招募的健康志愿者31名作为对照组,后者年龄、性别、受教育时间与创伤组相匹配。采集2组受试者临床数据和MRI数据,其中创伤组的数据采集在经历交通事故后1周内进行。采用所得DTI数据构建脑结构网络,比较2组脑结构网络属性的差异。结果:创伤组与对照组大脑结构网络均具有小世界属性。创伤组σ值、γ值较对照组升高,2组间差异具有统计学意义(P<0.05)。结论:急性创伤后早期脑结构网络具有小世界属性,其网络拓扑属性发生改变。

Purpose:To investigate the topological organization of brain white matter networks shortly after acute stress and to analyze the features of the"small world"network using diffusion tensor imaging(DTI)with graph theory method.Methods:Thirty-one motor vehicle accident(MVA)survivors and thirty-one age-,gender-,and education degree-matched healthy controls were recruited.All subjects got MRI scan and clinical evaluation.MVA survivors received MRI scan and trauma-specific clinical assessments within 1 week from MVA.Topological properties of brain white matter networks were analyzed using DTI with graph theory method.Results:The brain white matter networks fitted the definition of small⁃worldness in MVA survivors and controls.Significantly higherσandγvalues were found in MVA survivors as compared with those in controls(P<0.05).Conclusion:These results indicate that the brain white matter networks of MVA survivors exhibit small-worldness,but altered topological properties shortly after acute stress.