Yan S, et al. - In this prospective study, researchers examined the time-shift mapping created time-shift value of the brain by resting-state functional magnetic resonance imaging (rs-fMRI), as well as determined the differences in time-shift value among Alzheimer's disease (AD), mild cognitive impairment (MCI), and normal control (NC) groups. The study sample consisted of 24 AD, 24 MCI, and 24 age-matched NC participants. Results of this study suggested that the time-shift mapping method could noninvasively perceive perfusion deficits in AD and MCI. For understanding the mechanism of neurodegeneration, the perfusion deficits detected by rs-fMRI might provide new insight.