Application Study Of DKI In White Matter Microstructure Damage And Its Correlation With Cognitive Impairment In The CSVD

Objective To explore the damage of white matter microstructure and its correlation with cognitive impairment in patients with small cerebral vascular disease(CSVD)by DKI technique.Methods Ninety-three patients with CSVD and cognitive impairment admitted to our hospital from September 2017 to October 2018 were selected.All patients were divided into A or B groups according to Fazekas scale.Eighteen age-and gender-matched healthy volunteers were selected as controls.Conventional MRI and DKI scans were performed to obtain parameters of FA,MD and MK.Regions of interest were placed in the white matter of bilateral basal ganglia,corona radiata,centrum semiovale,posterior horn of lateral ventricle and genu of corpus callosum,splenium of corpus callosum which were normal in MRI T2-Flair images.The parameter values of FA,MD and MK were obtained.The differences of DKI parameter values between CSVD patients and controls were compared by t test.Montreal Cognitive Assessment Scale(MoCA)was used to score the nervous system of CSVD patients,and the correlation between DKI parameter value and MoCA score was calculated by linear regression analysis.Results Compared with the control group,in group A,FA value of the right corona radiata and MK values of the bilateral corona radiata,the right posterior horn of lateral ventricle were decreased.MD values of the right corona radiata,the right posterior horn of lateral ventricle were increased.In group B,FA value of the right centrum semiovale and MK values of the right corona radiata,the bilateral centrum semiovale,the left posterior horn of lateral ventricle were decreased.MD values of the right corona radiata and the right centrum semiovale were increased.The differences were statistically significant(P<0.05).In group A,some FA values and some MK values were positively correlated with MoCA scores,and some MD values were negatively correlated with MoCA scores,the most correlated sites were the right posterior horn of lateral ventricle(R=0.780,P<0.001),the left corona radiata(R=0.808,P<0.001)and the right centrum semiovale(R=-0.663,P<0.001).In group B,some FA values and some MK values were positively correlated with MoCA scores,and some MD values were negatively correlated with MoCA scores,the most correlated sites were the left centrum semiovale(R=0.779,P<0.001),the left posterior horn of lateral ventricle(R=0.782,P<0.001)and the left corona radiata(R=-0.650,P<0.001).There was no significant correlation between DKI parameter value and MoCA score in other parts(P>0.05).Conclusions(1)The decreases of FA,MK and the increase of MD in white matter of patients with CSVD which were normal in T2-Flair images can be detected by DKI,which indicated that DKI can identify the damage of white matter microstructures in early stage.(2)There was a linear correlation between DKI parameter and MoCA score,which proved to some extent that occult white matter injuries in CSVD patients can lead to cognitive impairment.