The Research Of Imaging Markers Focusing On Hippocampus In Unipolar Depressive And Bipolar Depressive

Objective: The Mood disorder including unipolar depressive(UD)and bipolar depressive(BD)exists some features wich cotain high prevalence rate and high recurrence rate leading to heavy burdern of diease.However,lacking of biomarkers make the clinical recognition and differential diagnosis to be challenges.Studies suggest that the hippocampus is one of the key area of emotion processing.Taking the hippocampus as seed,respectively,we adopt Automatic Brain Labeling and diffusion tensor fiber tracing to obtain the relative hippocampus volume value and basic index of diffusion tensor imaging(DTI)and fiber numbers(FN)of three groups including UD,BD and healthy control(HC).By analyzing the difference of these index among HC,UD and BD,which provides quantitative and qualitative indicators for the diagnosis and differential diagnosis of diseases.Methods: 35 UD and BD according with The Fourth Edition of the Diagnostic and Statistical Manual of Mental Disorders diagnostic criteria,accompanying with 35 HC matching with age,sex and education years were analyzed.All subjects underwent magnetic resonance imaging(MRI)scanning,acquiring the T1 and DTI data.1.label and calculate the relative hippocampus volume value of the three groups by Automatic Brain Labeling method.2.Taking the hippocampus as seed,we adopt diffusion tensor fiber tracing by DSIstudio to obtain and calculate basic index of DTI,then find the differences among three groups;furthermore,we calculate the FN evaluating the connective strength between areas between hippocampus and other areas.The spss22.0 was used to process data.Results:1.The relative hippocampus volume value: Compared to HC,UD and BD exist the reduction of the relative hippocampus volume value in both sides and total sum,especially,the UD group is smaller,while there exist some overlaps between the two diseases.2.The results of DTI index: Compared with HC,We only find radial diffusivity(RD)in the left hippocampus has significant difference(p<0.05)in BD group.While no significance parameter was found between UD group and the other two groups.3.The results of FN:(1)Compared with HC group,the reduction of FN value in UD patients mainly exists in frontal lobe(left inferior frontal gyrus)and occipital lobe(left middle occipital gyrus)(p<0.05);(2)Compared with HC,FN value of BD increase in limbic system(the left parahippocampal gyrus)and occipital lobe(tongue gyrus)in BD(p<0.05);(3)Partial correlation analysis found that RD mean of left hippocampus remain positively correlated with the duration of disease in BD group(r = 0.37,P = 0.041).Conclusions: Quantitatively and qualitatively,among HC,UD and BD,range of relative hippocampus volume value,DTI basic index and FN value exist some significant difference,Which can be the advice for early recognition and diagnosis of UD and BD.