【摘要】 目的分析脑梗死患者扩散峰度成像(DKI)各参数随梗死时间的变化规律,并与扩散张量成像(DTI)进行对比。方法对95例脑梗死患者行DWI、DKI扫描,并根据脑梗死的时间分为5组:超急性期10例、急性期12例、亚急性期早期33例、亚急性期晚期20例、慢性期20例,获得DKI的相关参数图,测量病变区及对照区各参数值并计算其百分比变化率,分析各参数值随时间的演变规律。结果 DKI各参数值[平均扩散峰度(MK)、径向峰度(K⊥)、轴向峰度(K//)]在梗死后升高,急性期达到高峰,之后随时间延长逐渐下降;DTI各参数值[平均扩散系数(MD)、垂直扩散张量(D⊥)、轴向扩散张量(D//)]在梗死后降低,急性期达到最低,随时间延长逐渐升高。MK、K⊥、K//的百分比变化率较MD、D⊥、D//更高,且平行方向变化均大于垂直方向。结论 DKI评价脑梗死优于DTI,可更全面地分析脑梗死微观结构的改变。更多还原

【Abstract】 Objective To evaluate the changes of diffusion kurtosis imaging(DKI)parameters with time in cerebral infarction patients,and contrast with diffusion tensor imaging(DWI).Methods DWI and DKI scans were performed in 95 patients of cerebral infarction.The patients were divided into five groups according to the time of cerebral infarction:Hyperacute phase(n=10),acute phase(n=12),early subacute phase(n=33),late subacute phase(n=20)and chronic phase(n=20).Parameters of DKI were obtained,and the parameters and percentage change of diffusion metrics from normal to ischemic tissue were compared.The evolution rule of parameter with time was analyzed.Results Mean kurtosis(MK),axial kurtosis(K//),radial kurtosis(K⊥)of DKI parameters increased after infarction,and reached the peak at acute phase,and decreased gradually with the prolonging of time.Mean diffusion(MD),axial diffusion(D//),radial diffusion(D⊥)of DTI parameters decreased after infarction,and reached the lowest at the acute phase,and increased gradually with the prolonging of time.The percentage change of MK,K//,K⊥ were higher than those of MD,D//,D⊥,and percent change along the axial direction were significantly larger than that along the radial direction.Conclusion DKI is superior to DTI in evaluating cerebral infarction,and can analyze the changes of microstructure of cerebral infarction comprehensively.更多还原