Technology And Application Of Brain Functional Network Connectivity Based On Neuroimaging

Biomedical signal belongs to low-frequency weak signal under strong noise background. It is unstable natural signals emitted by the complex organisms. The extraction and processing of human biological signal is the most difficult in the area of the natural science. It has become a hot topic subject of signal processing field. In recent years, with the development of neuroimaging technique and information processing technology, based on the information extraction and analysis of clinical imaging technology gradually become an important interdisciplinary scientific frontier. This has important value in clinical practice.Dissertation systematically analyzes the activation of the brain function of the network, undirected functional connectivity and directed functional connectivity. It bases on resting state functional magnetic resonance imaging and signal processing techniques and methods. These three processing technology are applied to bipolar disorder and post-traumatic stress disorder in the study. The main research contents and innovations are as follows:1. A study of brain activation pattern based on amplitude of low-frequency fluctuation in bipolar disorder. Using amplitude of low-frequency fluctuation technology extracted synchronous activation of brain regions and isolated dysfunction network functional from the angle of function orientation. The results showed that the default mode network(DMN) in patients with bipolar disorder was abnormal under resting state. DMN dysfunction may be one of the onset of bipolar disorder pathophysiology, and DMN associated with thought disorders.2. A resting state study of brain functional connectivity network based on independent component analysis in post-traumatic stress disorder. Independent component analysis technique based on blind source signal analysis, extracted each synchronization network as an independent component. We could research the abnormal changes of brain functional network from the multiple network level. This study found that functional connectivity of the dorsal attention network and self-reference network became abnormally higher, the connection of default mode network reduced. The results showed that the network in patients with post-traumatic stress disorder selected abnormal connection. And the abnormal connection was related to cognitive impairment and brain function evaluation regions.3. A resting state study of effective connectivity network based on granger causality analysis in bipolar disorder. DMN network was isolated from all brain network using spatial independent component analysis techniques. Eight key regions as interested regions were extracted from DMN inside. Then the condition granger causality analysis method was applied to calculate the granger causality of eight key brain regions and studied abnormal changes of brain function from the angle of effective connectivity network. The results showed that the left precuneus, the right angular gyrus and right temporal can drive the ventral middle prefrontal cortex, the right temporal can drive right precuneus. Results indicated that the thought disorders and emotional disorders drive each other parts of the brain regions, and precuneus was the key brain region of thought disorder.