Abstract:Subjective cognitive decline (SCD) is the early stage of Alzheimer's disease (AD), and the typical symptom is a decrease in the patient's memory. The incidence of SCD is increasing year by year, so it is urgent to prevent or delay the progression of the disease. In recent years, techniques such as magnetic resonance imaging (MRI) and brain network analysis have continued to develop. Scholars have evaluated the integrity of brain network structure and density by observing changes in SCD brain neurons and nerve fibers. This study summarizes and organizes literature on structural MRI, diffusion tensor imaging (DTI), and functional MRI. Based on the brain structure and functional characteristics of SCD, the article explores the pathophysiological mechanisms of brain network changes from multiple levels, searches for imaging biomarkers, analyzes shortcomings, and provides support for early detection and intervention of SCD.