Research Of Brain Network Of Alzheimer's Disease Based On The Magnetic Resonance Imaging

Alzheimer's Disease is a severe neurodegenerative disease that can cause dementia and mainly occurs in sixty-five years old and more.The cognitive function regression(such as memory deletion,attention damage,and executive function damage)is the complaint,and patients will lose self-care ability even death.Among the people over sixty-year-old,thirteen percent of them need long-term care,most of which is AD patients.And the cost for taking care of them is over $600 billion.Currently,There is no effective treatment for AD,while the physiological and pathological mechanisms are not clear.Therefore,the Magnetic Resonance Imaging(MRI)study of functional and structure abnormal in AD have great scientific and social value.This topic uses data of patients with AD,amnestic Mild Cognitive Impairment(aMCI)and Normal Control(NC)and analyzes the change of function and structure.We choose four functional brain networks which closely related to the AD: Default Mode Network,Dorsal Attention Network,Executive Control Network and Salience Network.Based on the connection change of brain network and the link with patient behavioral information,the author explores brain degenerative process in AD.The main contents are as following:1)Firstly,the author researches DMN and DAN.The study focuses on the change of intranetwork and internetwork Functional Connectivity(FC)and the correlation between FC and behavior.The results show the damage of intranetwork connection.The internetwork FC analyses indicate abnormal connection pattern and competitive change of DMN and DAN.2)ECN and SN which are two sub-network of Frontal-Parietal Control(FPC)system exert a regulation on DMN and DAN.Further,the author researches the performance of FPC system in AD.Based on FC analysis,the FPC system also has anomalous connection pattern.The ECN has a significant decrease of intranework FC.Even in aMCI group,the decline is also obvious.The SN represents a compensatory increase in the internetwork connection.The results indicate FPC system have the abnormal connection both in intranetwork and internetwork.3)After analysis of brain function,the author researches on if these dysfunctional brain networks have problems in the structure.Select T1 image for the Voxel-Based Morphometry analysis which could acquire the information about the content of grey matter in each voxel,and the result shows the shrink of Grey Matter Volume in the corresponding position.