Cerebral White Matter Analysis And Its Application Research Based Diffusion MRI

White matter tracts can control complex behaviors as the links between gray matter in brain.DTI is the only non-invasive imaging technique presenting the morphology and structure of white matter tracts.It can be used to research the microscopic white matter structure of normal or diseased tissues.DTI-based analysis methods are mainly divided into diffusion index analysis and white matter network analysis based graph theory.DTI image analysis can quantitatively evaluate damage of white matter tracts.By constructing white matter network,it can truly reflect fiber connection between cortex and subcortical structure.To expolre network topological features,it can reveal internal working mechanism of brain and pathophysiological mechanism of psychiatric diseases.In this research,we analyzed DTI metrics and topological properties of white matter network for non-clinical and clinical problems.The main contents of this paper are as follows:(1)Research on high anxious populations in white matter alterations.Trait anxiety is a personality characterizes by a longterm negative state,Despite the fact that a large body of literature related to anxiety-related disorders and white matter tracts are available,the relationship of trait anxiety in young healthy persons with the integrity of whole brain white matter is rarely studied.We selected diffusion tensor images of 38 high anxious and 34 low anxious subjects.Then,DTI diffusivity maps were computed and alterations of white matter tracts were evaluated by Tract-Based Spatial Statistics.Finally,we reported abnormal regions.In addition,the average DTI values of 50 core white matter regions was extracted by Atlas-Based Analysis,and to analyze damage of the whole white matter pathway.We controlled depression effects by using the depression scores as covariates.In conclusion,our study demonstrated that white matter abnormalities in young healthy individuals with high trait anxiety were mainly involved in some limbic areas related emotion that were widely reported in anxiety-related disorders.White matter alterations may be a potential marker in young healthy individuals with high trait anxiety.These investigations can elucidate the pathological mechanism of anxiety.The observed cerebral white matter changes in our study further support the need for preventive interventions in high anxiety individuals.(2)Research on abnormal white matter and its correlation with durations of disease in patients with TLE.With the onset of epilepsy,abnormal discharges of neurons spread to cortex and subcortical structure through white matter tracts.Therefore,a comprehensive assessment of diffusion alterations can provide accurate and effective information for understanding the extent of white matter tract injury.We collected 18 TLE patients and 29 normal control subjects and analyzed white matter changes through Tract-Based Spatial Statistics.We found that white matter changes not only occurred epileptic side,but also spread to contralateral side.In addition,the correlations between significant differences diffusion metrics of TLE patients and durations of disease were calculated(controlling for age of first onset).We found that the longer durations of disease,the more serious white matter damage.The abnormal white matter tracts were found more comprehensively by TBSS and ABA methods,which is expected to provide more accurate clinical diagnosis for TLE patients(3)Research on the abnormalities of whole white matter network and temporal lobe subnetwork in TLE patients.TLE can be considered as a network disorder with abnormal brain connections.This study analyzed the topological attributes of the whole brain network and the differences in the internal connections of temporal lobe subnetworks to evaluate the changes of brain networks in TLE patients more comprehensively.Cerebral white matter networks were constructed by using DTI and T1 images.Graph theory analysis showed that global network efficiency was significantly reduced and characteristic path length was significantly increased in TLE group,compared with normal control group.Hubs no longer included brain areas related temporal lobe(left middle temporal gyrus,right middle temporal gyrus and right inferior temporal gyrus).In addition,there was no significantly differences in temporal lobe intra-connectivity.This study can provide reliable basis for the study of pathological mechanism of TLE disease.