The Application Of Diffusion Tensor Imaging(DTI) Technique Of MRI In Patients With Subcortical Arteriosclerotic Encephalopathy(SAE)

Objective:to investigate the relationship between the microstructure alter of white matter fiber bundle and cognitive dysfunction in patients with subcortical arteriosclerotic encephalopathy(SAE)by using the anisotropy(FA)value and its changes of diffusion tensor imaging(DTI)technique of 3.0T ultra high field MRI.Methods:73 cases patients with SAE diagnosed by clinical and imaging diagnosis and 3~6 months after regular clinical treatment were collected,and 35 cases healthy elderly controls.All cases were informed consent by themselves(or their families).In this study,all the SAE patients before and after treatment and the healthy elderly control group were used SIEMENS MAGNETOM Skyra 3.0T magnetic resonance scanner to perform cranial magnetic resonance conventional sequence(T1WI,T2 WI,FLAIR,DWI)scanning and DTI examination.The following values were measured respectively: the FA values in the lesion area aside the lateral ventricle anterior and posterior angle and cerebrum oval center of SAE before and after treatment(the FA value of the corresponding area in the control group).Both SAE group and control group were cognitive measurement by the mini-mental state examination scale(MMSE)before and after treatment.The MMSE scores were recorded.Results:(1);before treatment,the FA value in each lesion area of SAE group were: left anterior angle =0.251±0.050,right anterior angle =0.251±0.009,left posterior angle=0.267± 0.058,right posterior angle =0.267±0.058,left cerebrum oval center=0.279±0.062,right cerebrum oval center =0.280±0.063,the MMSE score = 28.971±1.465;healthy elderly control group corresponding area FA values were: left anterior angle=0.387± 0.012,right anterior angle =0.385±0.009,left posterior angle=0.390±0.010,right posterior angle=0.395±0.029,left cerebrum oval center=0.398±0.016,right cerebrum oval center=0.398±0.024,the MMSE score=15.685±7.550;(2)According to the MMSE score before treatment in patients with SAE,which can be divided into light,moderate and severe three groups: 28 cases of mild group: MMSE score = 23.392±1.663,FA values: left anterior angle =0.306±0.024,right anterior angle =0.306±0.023,left posterior angle =0.330±0.030,right posterior angle =0.329±0.346,left cerebrum oval center=0.345± 0.036,right cerebrum oval center =0.347±0.036;23 cases of moderate group: MMSE score =15.565±3.101,FA values: left anterior angle =0.237±0.011,right anterior angle =0.236±0.017,left posterior angle = 0.248±0.013,right posterior angle =0.245± 0.013,left cerebrum oval center=0.260±0.017,right cerebrum oval center= 0.260± 0.023;22 cases of severe group: MMSE score = 6.000±2.070,FA values: left anterior angle =0.196±0.016,right anterior angle =0.198±0.013,left posterior angle =0.206 ±0.019,right posterior angle =0.210±0.030,left cerebrum oval center=0.212± 0.016,right cerebrum oval center =0.214±0.019;(3)According to the changes of MMSE score of the patients with SAE after treatment divided into improved group(MMSE score increased index?12%)and stable(including deterioration)group(MMSE score increased index < 12%),39 cases of improved group(mild:22 cases,moderate:12 cases,severe:5 cases),before treatment :MMSE score=18.462±6.517,FA values: left anterior angle =0.272±0.048,right anterior angle =0.273±0.047,left pos-terior angle =0.292±0.059,right posterior angle =0.272±0.048,left cerebrum oval center =0.306±0.064,right cerebrum oval center =0.290±0.059;after treatment: MMSE score = 21.718±6.817,FA values: left anterior angle =0.308±0.051,right anterior angle =0.309±0.047,left posterior angle =0.322±0.055,right posterior angle =0.324±0.055,left cerebrum oval center =0.339±0.059,right cerebrum oval center =0.326±0.057;34 cases of stable(including deterioration)group(mild:6 cases,moderate:11 cases,severe:17 cases),before treatment: MMSE score =12.529±7.512,FA values : left anterior angle =0.227±0.041,right anterior angle =0.226±0.038,left posterior angle = 0.240±0.043,right posterior angle =0.238±0.042,left cerebrum oval center = 0.248±0.043,right cerebrum oval center =0.249±0.044;after treatment: MMSE score =12.559±7.855,FA values : left anterior angle =0.227±0.041,right anterior angle = 0.226±0.038,left posterior angle =0.248±0.047,right posterior angle =0.250±0.045,left cerebrum oval center =0.255±0.042,right cerebrum oval center =0.258±0.044.Conclusion:(1)The differences between the two groups corresponding regional FA values were statistically significant in patient with SAE group and healthy elderly(P<0.05),namely: the lesion area FA values in patients with SAE compared with the normal control group,the corresponding region of low FA value,indicating the existence of microstructural alters of white matter of the fibers lesion area in patient with SAE,the accurate measurement of the FA value of the patient's lesion area is of clinical value for the diagnosis of SAE.(2)The difference of FA value in the corresponding area of SAE patients with different degree(light / moderate / severe)cognitive impairment before treatment is statistically significant(P<0.05),namely: the higher the degree of cognitive impairment in SAE patients,the lower the FA value in the corresponding lesion area;Com-paring the FA value in the focus area of the SAE patients has the applied value in judging the degree of pathological changes in SAE patients.(3)In improvement group,the difference between the FA values of the area after treatment and the FA values of the lesion area before treatment is statistically significant(P<0.05);In stable(including deterioration)group,the difference between the FA values of the lesion area after treatment and the FA values of the lesion area before treatment is not statistically significant(P > 0.05);By comparing the changes of the FA value before and after the treatment,the imaging basis can be provided for the treatment effect and the prognosis of the patients with SAE.(4)The rates of improvement in SAE patients with different degrees of cognitive impairment were respectively:mild:78.6%,moderate:52.3%,moderate:22.7%,there was a statistical difference amony them(P<0.05);The earlier diagnosis of SAE patients,the prognosis and treatment will be better,therefore,the early diagnosis of SAE patients by DTI technology can provide an opportunity for early intervention for patients to improve the prognosis of SAE patients.