PSEN1 and Alzheimer disease: In search of early diagnostic imaging markers for AD, we used sMRI, rs-fMRI, and 1H-MRS technology to find out: Compared with wild type mice, the volume of the left hippocampus and right olfactory bulb of APP/PS1 transgenic AD model mice was reduced, the functional activity of the bilateral hippocampus, right piriform cortex, and right caudate putamen was reduced, the functional network connectivity of the hippocampus was impaired, and the relative content of NAA in the hippocampus was decreased.