Objective To analyze the correlation of extracranial hemodynamic parameters and intracranial stenosis in patients with ischemic stroke

and to explore its clinical diagnostic value.Methods Ninety patients with different degrees of stenosis in the intracranial segment of unilateral vertebral artery were selected retrospectively.According to the results of CTA or DSA of head and neck

25 cases were classified as mild stenosis

37 cases as moderate stenosis

28 cases as severe stenosis.The peak systolic velocity（PSV）

end diastolic velocity（EDV）

resistance index（RI） and time average peak velocity（TAPV） of vertebral artery V2 segment were measured and recorded by color Doppler ultrasound.Meanwhile

the blood flow of vertebral artery（Q） was calculated and the correlation between PSV

EDV

RI

Q and the degree of intracranial stenosis of vertebral artery was analyzed.ROC curve was drawn to analyze the value of PSV

EDV

RI

Q in the diagnosis of intracranial vertebral artery stenosis.Results PSV

EDV and Q of patients with moderate and severe stenosis were lower than those of patients with mild stenosis

and those with severe stenosis were lower than those of patients with moderate stenosis（all P<0.05）.RI of patients with moderate and severe stenosis was higher than those of patients with mild stenosis

and that with severe stenosis was higher than that of patients with moderate stenosis（all P<0.05）.Correlation analysis showed that PSV were negatively correlated with mild

moderate and severe stenosis（r=-0.613

-0.607

-0.621

all P<0.05）.EDV were negatively correlated with mild

moderate and severe stenosis（r=-0.617

-0.601

-0.828

all P<0.05）.RI were positively correlated with mild

moderate and severe stenosis（r=0.527

0.604

0.753

all P<0.05）.Q were negatively correlated with mild

moderate and severe stenosis（r=-0.609

-0.624

-0.813

all P<0.05）.The area under ROC curve of combined diagnosis of PSV

EDV

RI and Q was 0.893（95%CI:0.821-0.965）

the sensitivity was 92.8%

the specificity was 96.7%

which were higher than those of single diagnosis of vertebral artery stenosis.Conclusion The hemodynamic parameters of the extracranial vertebral artery in patients with ischemic stroke are correlated with different degrees of intracranial stenosis

and the combined diagnosis of PSV

EDV

RI

Q has a high diagnostic value.