| Objective:Using MR to find the relativity between the changes of 1H magnetic resonance spectroscopy (1H-MRS),structure of brain in aMCI, AD patients and normal control group.These can be used as an assistant tool to diagnosis aMCI and AD in early stage,to differential diagnosis,and to monitor the develop of disease.Methods:Normal scanning,1H-MRS and Hippocampus volume measurements of VOI are acquired by siemens Novus 1.5T MRI system.Single voxel 1H-MRS examination:using single voxel sequence of SVS-SE-30 sequence, the acquisition voxel size in medial temporal lobe is 1.2×1.2×1.2(cm3), the acquisition voxel size in left posterior cingulate is 1.5×1.5×1.5(cm3), TR 1500ms, TE 30ms, interval time(TM) is 13.7ms,256 samples,8-phase cycle, bandwidth 2500Hz.. N-acetyl aspartate (NAA), choline (Cho) and myo-inositol (mI) and creatine (Cr) was measured, and calculate the ratio of NAA/Cr, NAA/ml and ml/Cr.Hippocampal volume measurement:location on the basis of the routine scan of hippocampus. IR-PDWI-Tfl3D sequence was taken in the oblique-coronal position of hippocampal long axis:TI 1100ms; TR 1830ms; TE 3.93ms; scanning:three times, slice thickness 1.2 mm, FOV 25CM, matrix 256×256, continuous scanning with no interval. Scan range:including amygdala, anterior and posterior horn of lateral ventricle.Comparing difference of the ratio of NAA/Cr, NAA/mI, Cho/Cr, mI/Cr in these three groups (NC, aMCI and AD).analysis of the correlation of metabolite ratios and cognitive function,comparison the differences of hippocampal volume in each group, the relevance of metabolite ratios and hippocampal volume,the Features of metabolite of two major type symptoms of TCM (Shenjingkuixu, Tanzhuo)are all included.Results:1.NAA/Cr of left medial temporal lobe in aMCI and AD groups were lower than NC group with statistical significance(P<0.05), AD group and the aMCI group has not statistically significant difference (P>0.05); NAA/ml in aMCI and AD group lower than NC group with statistically significance(P<0.05), There was not statistically significant differdnce in AD group and the aMCI group (P>0.05). NAA/mI of right medial temporal lobe in AD and aMCI group lower than NC group with statistically significant (P<0.05).There are no statistical significance difference of NAA/Cr, Cho/Cr, ml/Cr and NAA/mI located in left posterior cingulate gyrus of aMCI, AD and NC groups. Metabolites asymmetry index of two sides of medial temporal lobe of aMCI group and NC group was statistically significant difference (p<0.05), metabolites asymmetry index of other position have no significant difference.2. (1) relevance of MMSE score and 1H-MRS of aMCI, AD Group:NAA/ Cr located in left posterior cingulate gyrus was negative-related (r=-0.709, (P <0.05) with MMSE in aMCI group, while there was no significant correlation with other metabolic. (2) relevance of DSR scales and 1H-MRS of aMCI and AD group, the NAA/Cr of left medial temporal lobe was positively correlated with DSR(r= 0.648, P<0.05) in aMCI, the NAA/mI of the left posterior cingulate gyrus were positively correlated (r= 0.673, P<0.05)with DSR in AD group, (3) relevance between ISR score and 1H-MRS in aMCI and AD Group:NAA/Cr were positively correlated with ISR in left medial temporal lobe of aMCI group (r= 0.629, P= 0.051), and Cho/Cr were positively correlated with ISR (r= 0.660, P<0.05), the NAA/mI in the left posterior cingulate gyrus of positive correlate with ISR in AD group (r= 0.658, P<0.05).3.comparation hippocampal volume among three groups:both sides of the hippocampal volume in AD group was significant differdent with NC and aMCI group (p<0.05).There is no significant difference in NC and aMCI groups on both sides of hippocampal volume (p>0.05); both sides of hippocampal volume of AD and aMCI groups did not significantly associated with the metabolite ratios in these three position.4. NAA/Cr and MMSE has positive correlation in the left medial temporal lobe of the Tanzhuo group (r= 0.498, P<0.05); NAA/mI and MMSE has positive correlation (r=0.462, P<0.05),while this correlation was not exist in right medial the temporal lobe; NAA/mI were positively correlated (r=0.585, P<0.05)with MMSE in the right medial temporal lobe of the Shenjingkuixu group, but not exist in the left medial temporal.Conclusion:The study found that hippocampal volume measurement has important value in identifying aMCI and AD,1H-MRS have a relatively high sensitivity in detection and identification of aMCI and NC.Combining these two kinds of Methods can monitoring pathology change of the course of NC→aMCI→AD and it is the best choice to identify aMCI and AD.DSR and ISR have relevance with NAA/Cr in the left medial temporal lobe, DSR is more Significantly, in these three kinds of scales MMSE(mini-mental state examination), DSR (delayed story recall), and ISR(instant story story recall). It suggest that delayed story recall (DSR) can be used to diagnosis aMCI and mild AD. NAA/mI,NAA/Cr in the left posterior cingulate gyrus closely associated with AD suggesting it can be used as reference for the diagnosis of AD.The study found that NAA/Cr, NAA/ml in left medial temporal lobe has positive correlation with MMSE in the Tanzhuo group, while NAA/ml in right medial temporal lobe has significant positive correlation with MMSE in the Shenjingkuixu group. Metabolism changes in different TCM type of aMCI. Which obviously involved in the left medial temporal lobe in the Tanzhuo group, involved in the right medial temporal lobe in the Shenjingkuixu. The study of combining metabolic and syndromes in Chinese medicine in cognitive dysfunction patients, will become an important research direction in the future.
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