This disclosure relates to a magnetic resonance imaging device. The magnetic resonance imaging device includes an carrying unit； an imaging unit, a controlling computer, and a signal processing computer. The signal processing computer includes a controlling module, a data processing module, an image reconstructing module, an image storing module, and an image comparing module. The image reconstructing module forms cross-sectional scanned images of an user's brain memory showing microstructure. The image comparing module is configured to analyze and compare the cross-sectional scanned images of the user's brain memory showing microstructure captured at different times so that the controlling computer shows different suggestions corresponding to different judgement results of the image comparing module. The system may comprise a dementia monitoring system that provides users with advisory dementia warnings so users may be advised to seek further medical advice.
