Study Of Proton Magnetic Resonance Spectroscopy And Diffusion Tensor Imaging In Patients With Vascular Cognitive Impairment No Dementia

The research is divided into two parts,Using proton magnetic resonance spectroscopy（~1H-MRS）and diffusion tensor imaging（DTI）technology to detect cerebral gray mattermetabolic alterations and white matter occult damage in patients with vascular cognitiveimpairment no dementia(VCIND),analyzing the correlation between~1H-MRS,DTIparameters and Montreal Cognitive Assessment(MoCA) score in VCIND group,evaluatingthe application values of~1H-MRS and DTI technique on cerebral gray matter and whitematter in early diagnosis and disease monitoring of VCIND.The first part: Study of Proton Magnetic Resonance Spectroscopy inpatients with Vascular Cognitive Impairment No DementiaObjective:Using single voxel~1H-MRS technology to detect cerebral gray mattermetabolic alterations in patients with VCIND, analyzing the correlation between~1H-MRSindexes and MoCA score in VCIND group, evaluating the application values of~1H-MRSexamination on cerebral gray matter in early diagnosis and disease monitoring of VCIND.Materials and methods:34patients with VCIND and26matched volunteers werecollected, and all subjects received single voxel~1H-MRS examination to detect of N-acetylaspartate (NAA), choline compounds (Cho) and creatine/phosphocreatine (Cr) on bilateralthalamus,using relative quantitative method to get NAA/Cr, Cho/Cr. Comparing thedifferences of NAA/Cr, Cho/Cr on bilateral thalamus between two groups, and analyzingthe correlation between NAA/Cr, Cho/Cr and MoCAscore.Results:1. NAA/Cr on bilateral thalamus in VCIND group were both lower than the control group, the difference was statistically significant (P<0.05),There were no significantdifferences in Cho/Cr on bilateral thalamus between the two groups (P>0.05)；2. In VCINDgroup, there were significantly positive correlation between NAA/Cr on both bilateralthalamus and MoCA score (P<0.05),there were no significant correlations betweenCho/Cr on both bilateral thalamus and MoCAscore (P>0.05).Conclusion:1.Bilateral thalamus exist nerve cell loss or functional decline inpatients with VCIND, the metabolic alteration on bilateral thalamic may be an importantfactor leading to cognitive impairment in patients withVCIND;2.~1H-MRS technology cansensitively detect early metabolic changes in patients with VCIND;3. The change ofNAA/Cr on thalamus can reflect the degree of cognitive impairment in patients with VCINDon some extent;4.~1H-MRS detection on bilateral thalamus contributes to early diagnosisand disease monitoring in patients with VCIND. The second part: Study of Diffusion Tensor Imaging in Patients withVascular Cognitive Impairment No DementiaObjective:Using DTI technology to understand the characteristics of cerebral whitematter occult damage in patients with VCIND, evaluating the application values of DTIexamination on cerebral white matter in early diagnosis and disease monitoring in patientswith VCIND.Materials and methods:27patients with VCIND and24matched healthyvolunteers were collected, and all subjects received DTI scanning.After scanning,transferringthe images to post-processing workstation,and measuring fractional anisotropy(FA) andapparent diffusion coefficient(ADC) on bilateral frontal white matter, callosum genu andsplenium.Comparing the differences of FA and ADC values on different regions of intresestbetween the two groups, and analyzing the correlation between DTI parameters and MoCAscore in VCIND group. Results:1.FA values on bilateral frontal white matter in VCIND group were lowerthan control group, and ADC values were higher than control group, the differences wasstatistically significant (P<0.05); There were no significant differences in FA and ADCvalues on callosum genu and splenium between two groups (P>0.05);2.In VCIND group,FA value of bilateral frontal lobe white matter were positively correlated with the MoCAscore (P<0.05),and ADC value were negatively correlated with the MoCA score(P<0.05);there were no significantly correlations between FA and ADC values on callosumgenu and splenium and MoCAscore (P>0.05).Conclusion:1.Bilateral frontal white matter exist fiber occult damage in patientswith VCIND, which may be an important cause result in cognitive impairment in patientswith VCIND;2.DTI parameters are sensitive to reflect occult damage on white matter inpatients with VCIND;3.The change of FA and ADC value can reflect the severity ofcognitive impairment on a certain degree in patients with VCIND;4.DTI detection onfrontal white matter contributes to early diagnosis and disease monitoring in patients withVCIND.