A Study On Diffusion Tensor Imaging And Magnetic Resonance Spectrum Imaging For Predicting The Development Of Amnestic Mild Cognitive Impairment

Objective To predict the transformation from amnesia mild cognitive impairment(aMCI)to Alzheimer’s disease(AD)according to clinical classification by magnetic resonance spectroscopy(MRS)and diffusion tensor imaging(DTI)of posterior cingulate gyrus.Methods A collection of 40 patients with amnestic mild cognitive impairment(aMCI)in the Neurology Clinic of the First Affiliated Hospital of Jinzhou Medical University and20 healthy aged volunteers were recruited during the same period.They received a complete neuropsychological evaluation and MRS,DTI inspection during the baseline period.Clinical reassessment was carried out after an average of 24 months.AMCI patients who converted to dementia within 2 years were classified into the aMCI conversion group(aMCI-c(12 cases),and those who did not convert to dementia were classified into the aMCI stable group(aMCI-nc(28 cases)).After collecting the posterior cingulate gyrus(PCG)FA and NAA/ml values,analyze and compare the difference between the measured values of the two functional imaging groups and the clinical evaluation results,the diagnostic efficiency and the best diagnostic threshold,then compare the difference between the two scanning methods in predicting the development of mild cognitive impairment to Alzheimer’s disease in the area under curve(AUC).Finally,the correlation between these values and neuropsychological scores was analyzed.Result1.There was no significant difference in age,sex and years of education b etween the three groups(P=0.260,P=0.532,P=0.832),while the baseline per iod of the three groups was statistically significant(P=0.000,P=0.000,P=0.001),and each score in the aMCI-c group was lower than that in the aMCInc group and the NC group;2.Compared with the aMCI-nc group during the baseline period,the FA value and NAA/ml ratio in the aMCI-c group decreased,and the difference was statistically significant(P=0.020,P=0.001).The FA value in the PCG of aMCI-c group and aMCI-nc group was lower than that of the control group(P=0.000,P=0.016);3.There was no significant difference in NAA/ml value between aMCI-nc group and NC group(P=0.606);The area under the curve of the working characteristic curve of the subjects whose FA value and NAA/ml ratio were predicted to be converted to AD was 0.733,0.830 and the best diagnostic values were0.461,1.884,which can distinguish the aMCI conversion group from the stable group;The combined use of DTI and MRS is better than scanning alone in predicting the conversion of aMCI into AD in two years.The difference is statistically significant(P=0.000),and its AUC is greater than either DTI or MRS(AUC=0.920);4.There was a positive correlation between aMCI-c group’s MMSE,Mo CA,IADL score and the posterior cingulate NAA/ml(r=0.604,r=0.668,r=0.587,P=0.038,P=0.017,P=0.045),There was a positive correlation between the total MMSE,Mo CA score of aMCI-c group and the FA value of posterior cingula te gyrus(r=0.645,r=0.626,P=0.024,P=0.030).Conclusion1.The FA,NAA /ml values of MRS and DTI in a certain range are effective indicators to predict the conversion of aMCI into AD within two years;2.There is a certain correlation between FA,NAA /ml measured value and neuropsychological score in baseline PCG.