Research And Application Of Diffusion Tensor Imaging Data Processing Method

Diffusion tensor imaging(DTI) is a new noninvasive magnetic resonance imaging(MRI)technique. DTI not only can provide quantitative analysis of the diffusion of water molecules in a three-dimensional space, but also can use the anisotropic characteristics presented by the diffusion of water molecules to image. In recent years, DTI has been used in clinical research, and become a kind of new methods in clinical diagnosis of the white matter disease, cerebrovascular disease and mental disorder. In this study, DTI was mainly used to investigate the radiological manifestation of bilateral mesial temporal lobe epilepsy and social anxiety disorder.Mesial temporal lobe epilepsy (mTLE) is one of the most common focal epilepsy, the patient will grant exception potential during an attack. To investigate changes in fiber integrity along with diffusivity in the bilateral mTLE patients, we study the diffusion parameters and fiber density index (FDI) of DTI by the voxel-based analysis (VBA) method. The results show that there were diffusion abnormalities in the bilateral hippocampus in patients. The results were in line with previous studies. Furthermore, we found the abnormalities of fiber integrity in bilateral hippocampus and lose of the relativity among the parameters. The results demonstrate the abnormality of structural connection in hippocampus in the bilateral mTLE patients, which provides important reference value for the study of the pathogenesis of epilepsy.The previous study of social anxiety disorder (SAD) showed that the patients of SAD had cognitive dysfunction. Structure is the carrier of the function, in order to explore whether there are anomalous structural connections in SAD, we studied the structural network of SAD by DTI. Through the study of the methods in white matter fiber tracking, back-projection of the standard brain template to the original space, the reconstruction of the brain structural network, we got the algorithm of the analysis of the structural network. And then we implement the algorithm at DTI data of SAD. The results show that there were reduce of the structural connections among temporal lobe and angular gyrus, temporal lobe and insula, temporal lobe and hippocampus, frontal lobe and insula, frontal lobe and anterior cingulated cortex, precuneus and parahippocampal gyrus, precuneus and superior parietal lobe in the left brain, and among temporal lobe and angular, temporal lobe and occipital lobe, frontal lobe and insula, precentral gyrus and supramarginal gyrus in the right brain. The regions involved in these reduced structural connections are consistent with the results reported in the previous studies about SAD, which indicates that there are abnormal nerve fiber connections among multiple brain regions in patients of SAD. It has important reference value in the study of neural mechanisms of SAD.