The Application Of DTI Combined With MRS In The Cerebral Small Vessel Disease

Objective:The relevant parameters of normal appearing white and gray matter in cerebral small vessel disease(CSVD)were measured by diffusion tensor imaging(DTI)and magnetic resonance imaging(MRS),and changes of intracerebral microstructure and metabolite were reflected quantificationally.The study aimed to explore the value of DTI combined with MRS in the identification and diagnosis of early occult lesions of CSVD and guide the clinical practice.Methods:1.Routine magnetic resonance imaging and DTI imaging were performed in 53 patients with clinically diagnosed CSVD and 36 matched healthy persons of the same age,and frontal lobe normal appearing white matter(NAWM)was selected as region of interest.The fractional anisotropy(FA)value and apparent diffusion coefficient(ADC)value of three fiber bundles in frontal lobe were measured.Then the conventional MR scanning of apparent diffusion coefficient on T2-FLAIR phase in CSVD patients were graded(Refer to the Fazekas scale)to investigate the correlation between DTI parameters in NAWM area and Fazekas score of WMH.2.Participants were measured by MRS to determine the contents of biochemical metabolite N-acetylaspartate(NAA),Choline(Cho),Creatine(Cr)of normal appearing gray matter in basal ganglia area(Caudate nucleus and lenticular nucleus)and make calculation and analysis of NAA/Cr,Cho/Cr and other values.Results:1.DTI: In 53 patients with CSVD,there was 13 cases showed no obvious abnormality between FA value and ADC value in frontal lobe NAWM area.In 40 cases of CSVD patients,the FA value of frontal lobe NAWM area decreased and ADC value increased to various extend,and the difference is significant compared with the control group.The Fazekas scores of T2-flair WMH in 53 patients with CSVD were graded.The results showed that there was a negative correlation between FA value and Fazekas score.There was a positive correlation between Fazekas score and FA value.That is,the more serious the white matter burden in the whole brain of CSVD patients,the lower the FA value in NAWM area of frontal lobe,and the more serious the damage of white matter integrity in frontal lobe.2.MRS: Among 53 patients with CSVD,41 cases had decreased NAA/Cr ratio of NAGM area in caudate nucleus.The difference was statistically significant(t=-4.54,P<0.05).The NAA/Cr ratio of NAGM region in lentiform nucleus decreased in 35 cases,and the difference was statistically significant(t=-3.83,P<0.05).There was no significant difference in Cho/Cr ratio between the two groups(t=0.84,P>0.05),(t=0.75,P>0.05).Conclusions:1.DTI can show the white matter microstructure with a unique advantage,and provide quantitative evaluation of the degree of white matter integrity damage in the early stage of CSVD patients and a visual objective basis for occult white matter injury.The change of FA value of DTI anisotropy parameter is correlated with Fazekas score which can provide effective evaluation basis for early clinical prevention of WMH progression in CSVD patients.2.The metabolites in the NAGM region of the gray matter nucleus was measured by MRS,which can quantitatively analyze the characteristics of early gray matter metabolism in the patients with CSVD,and the provide metabolite monitoring indexes for the clinical prevention of lacunar cerebral infarction.