Brazilian Journal of Radiation Technology Research · Mar 10, 2026
ABSTRACT: Importance of magnetic resonance imaging in the early detection of Alzheimer's disease
By Filho FJAO
Alzheimer's disease (DA) is a progressive neurodegenerative disease that causes cognitive and functional impairment, and early diagnosis is essential for more efficient clinical intervention, family planning, and risk management. Over the past five years, magnetic resonance imaging (RM) has become established as a crucial tool for identifying structural and functional changes in the brain long before clinical manifestations, contributing to earlier and more accurate diagnosis. The objective of this study is to present an updated review (2021– 2025) of the main contributions of RM, both structural and functional, to the early detection of Alzheimer's disease, highlighting advances in imaging techniques, artificial intelligence, biomarkers, and integration with other neuroimaging modalities. The methodology used was a narrative review of recent literature (2021–2025) in databases such as PubMed and Scopus and specialized journals, including structural (sMRI) and functional (fMRI) approaches, multimodal studies, automatic segmentation, and artificial intelligence systems for image analysis. Volumetric analysis using sMRI demonstrated prior changes in the volumes of the hippocampus and cerebral cortex that can be detected approximately 10 years before clinical symptoms, facilitating diagnosis at the prodromal stage. Combined sMRI and DTI techniques, integrated with neural networks such as YOLOv11, have significantly improved sensitivity and specificity in the early detection of Alzheimer's disease in its initial stages. Advanced methods using neural networks, such as DenseNet-201, ResNet, and CNN combined with slice selection techniques, have been achieving diagnostic accuracy above 82%.