Objective To investigate the clinical effect of arterial spin labeling（ASL） in measuring cerebral blood flow（CBF） in patients with mild Alzheimer’s disease（SCD） and mild cognitive impairment（MCI） to provide reference for clinical diagnosis. Methods A total of 108 patients with Alzheimer’s disease（AD） admitted to the Neurology Department of Xuchang Central Hospital from February 2019 to December 2020 were selected as the study subjects

including 54 patients with SCD（SCD group） and 54 patients with MCI（MCI group）

and another 50 healthy elderly patients who received physical examination during the same period were selected as controls. All patients underwent 3D-ASL image acquisition to detect CBF values in eight bilateral brain regions [globus pallidus（GP）

putamen（PU）

caudate nucleus（CA）

hippocampus（HP）

thalamus（TH）

frontal cortex（FC）

parietal cortex（PC）

and occipital cortex（OC）]. The obtained data were statistically analyzed. Results There were significant differences in Montreal Cognitive Assessment（MoCA） scores among the three groups（P<0.05）

and the scores increased in turn following the order of MCI group

SCD group

and control group. There were significant differences in CBF values of GP

PU

CA

HP

TH

FC

PC

and OC in the three groups（all P<0.05）. The CBF values of GP

PU

CA

HP

TH

FC

PC

and OC in the MCI group were significantly lower than those in the SCD and control groups; while the CBF values of PU

CA

and TH in the SCD group were significantly higher than those in the control group（P<0.05）. In addition

CBF values of HP

FC

PC

and OC were positively correlated with MoCA scores in the study subjects（r=0.482

0.325

0.311

0.354

all P<0.05）. Conclusion The ASL technique can accurately measure CBF to diagnose the severity of patients with AD and can provide reference for distinguishing SCD from MCI. These benefits hold promise for a wider application of this technique clinically.