DTT及VBM联合评价精神发育迟滞患者脑白质变化

A study of white matter in mental retardation patients by combining diffusion tensor tractography and voxel-based morphometry

目的:联合使用扩散张量纤维束示踪成像(DTT)及基于体素的形态分析法(VBM),探讨精神发育迟滞(MR)患者的脑白质变化。方法:精神发育迟滞患者16例及同龄健康志愿者16例(对照组),均行MR 3D-T1WI及DTI扫描,采用VBM方法比较患者组与对照组中脑白质体积的差异。同时使用DTT重建特定脑白质纤维束,比较患者组与对照组中白质纤维束的FA值、ADC值、数量和长度的差异。结果:与正常对照组比较,MR患者的脑白质体积总量减少(t=2.457,P<0.01),扣带束、下额枕束的FA值降低(t=-2.561、-2.92,P=0.013、0.005),胼胝体束、下额枕束、皮质脊髓束和扣带束的ADC值增高(t=3.039、2.524、2.483、2.292,P=0.006、0.016、0.016和0.025),皮质脊髓束、胼胝体束的数量减少(t=-2.195、-2.385,P=0.033、0.024),胼胝体束、皮质脊髓束、扣带束长度减小(t=-2.146、-2.364、-2.048,P=0.040、0.021、0.045),差异均有统计学意义(P<0.05)。结论:DTT及VBM方法均可发现精神发育迟滞患者脑白质异常变化,两者联合使用对精神发育迟滞的评估有重要价值。

Objective：To investigate abnormalities of cerebral white matter in patient with mental retardation by using diffusion tensor tractography （DTT）and voxel-based morphometry （VBM）.Methods：Three dimensional T1 WI and diffu-sion tensor imaging were performed both from 16 patients and 16 age and gender matched healthy controls using 1.5T MR scanner （Philips）.The data were processed with DTT and VBM,including the whole brain white matter analysis and some special white matter fibers.Results：The whole white matter volume decreased in patients when compard with that in healthy controls （t= 2.457,P〈0.01）.Compared with healthy controls,the FA value in cingulate fasciculus and fronto-occipital fas-ciculus statistically significantly decreased （t= -2.561 and -2.92,P= 0.013 and 0.005）,the ADC value in corpus callo-sum,fronto-occipital fasciculus,corticospinal tracts and cingulate fasciculus statistically significantly increased （t= 3.039, 2.524,2.483 and 2.292,P= 0.006,0.016,0.016 and 0.025）,the virtual fiber numbers of corticospinal tracts and corpus callosum statistically significantly decreased （t= -2.195 and -2.385,P= 0.033 and 0.024,respectively）,and the virtual fiber lengths of corpus callosum,corticospinal tracts and cingulate fasciculus were significantly decreased （t= -2.146,-2.364 and -2.048,P= 0.04,0.021 and 0.045）.Conclusion：Both DTT and VBM can measure the changes of white mat-ter in mental retardation patients.Combination of DTT and VBM is a sensitive method to display and evaluate alteration of white matter in mental retardation.