Study On The Pathogenesis Of Depression By Multimodal Magnetic Resonance Imaging

Objective Data processing was performed on structural magnetic resonance images and resting state functional magnetic resonance images collected from patients with depression,and changes in gray matter volume and spontaneous neuronal activity in different brain regions were analyzed,and changes in brain functional networks were discussed and summarized,so as to further understand the pathogenesis of depression.Methods A total of 25 patients with depression who had not been regularly treated with medication for the first time and 25 healthy controls were collected.All subjects collected general information such as gender,age and education level according to the self-made case report form(CRF)at baseline,and received craniocerebral magnetic resonance examination.All subjects were assessed on the Hamilton Depression Scale for clinical symptoms and severity.1.VBM8 toolkit in SPM8 software was used to calculate the cortical index based on the structure image.Subjects with significant artifacts of T1 structural images were removed,and then tissue segmentation and spatial standardization were performed.Dartel method was used to register the structural images of the subjects,and gray matter and white matter volumes were calculated.The smoothing core FWHM was set to 8mm for spatial smoothing of the results.2.Use DCM2 NII to convert DICOM files into NIFTI files.The subjects with obvious artifacts were removed,and the functional magnetic resonance(f MRI)was preprocessed using SPM12-based RESTPlus.According to the image quality,the first 10 time points of the image were removed;Time layer correction and head movement correction;According to the T1 image of the same subject as the structural image,Dartel’s method was used to register to the MNI standard vertebral space for origin correction and space standard vertebral localization.The smoothing core FWHM is set to 6 for spatial smoothing;Continue to give linear trend removal,filtering,noise reduction treatment.3.Double sample t test was performed with SPM12,and gender,age and education level were taken as covariates.According to the original P-value threshold of 0.001 at the voxel level,the P value of 0.05 corrected by FDR was used as the threshold to obtain the statistical results of structural magnetic resonance,functional magnetic resonance and functional connectivity,respectively.Results Compared with the healthy control group,the gray matter volume of the right inferior temporal gyrus,left thalamus,right inferior occipital gyrus,right orbital superior frontal gyrus,right middle occipital gyrus,left superior temporal gyrus,left middle occipital gyrus,left inferior frontal gyrus of the left island lid,and left middle frontal gyrus decreased in the depressed patients.Compared with healthy controls,the right middle frontal gyrus,left middle frontal gyrus,left superior frontal gyrus and left medial superior frontal gyrus had higher resting state local concordant(REHO),and no reduction of REHO was found in depressed patients.Low frequency amplitude(ALFF)increased in3 brain masses in 2 brain regions of right precuneus and right caudate nucleus in patients with depression,but no ALFF decreased in brain regions was found.Low frequency amplitude(fALLF)of the ratio of the left auxiliary motor area decreased in patients with depression,and Falff of the left caudate nucleus increased.In terms of brain functional connectivity,in patients with depression disorder,the functional connectivity(FC)of right precentral gyrus and left precentral gyrus were weakened when the left medial superior frontal gyrus was the area of interest(ROI),while the right precuneus was weakened when the right precentral gyrus and left posterior central gyrus were weakened.Conclusion The function and functional connectivity of gray matter and resting state were abnormal in patients with depressive disorder.The abnormal function of resting state may be a biological marker for the diagnosis of depressive disorder.The extent of damage to the local consistency of baseline resting state in depressive disorder patients is expected to be a guideline for early intervention.