| Objective:Digital subtract angiography(DSA)for diagnosis standards,worked out the best diagnostic threshold of blood flow velocity varying degrees of the middle cerebral artery,and other indicators to assess vascular stenosis.Methods:Collect symptomatic patients who were admitted to the Department of Neurology and finished TCD and digital angiography,Bethune First Hospital,Jilin University from 2019 June 1 to 2020 November 30.It will be divided into five groups: normal group,mild stenosis group,moderate stenosis group,severe stenosis group,and occlusion group,depending on the result of DSA.Collecting data of Peak systolic velocity,End Diastolic velocity,Mean blood flow velocity of bilateral MCA,MCA stenosis distal end,ACA,PCA,pulsatility Index,spectrum shape,audio frequency.The PSV,EDV,MFV of each group were subjected to a multivariate analysis of variance;the area under the receiver operator characteristic(ROC)curve was used to determine the best critical value for different degrees of MCA stenosis.Divide the vascular stenosis of patients into two groups,the occluded side and the contralateral side.Record the PSV on the occluded side of the MCA,the PSV ratio of the MCA on the occluded side to the ipsilateral ACA(MCA/iACA),and the PCA on the occluded side and the same side PSV(MCA/iPCA);PSV ratio(MCA/iACA,MCA/iPCA)between the healthy side MCA and the ipsilateral PCA,ACA,t test between the two groups,compare the MCA,MCA/iACA,MCA/iPCA between the two groups in PSV,The difference between PI.Results:A total of 151 patients were collected,including 135 males(89.4%)and 16females(10.6%),with an average age of(58±10)years.The interval between TCD and DSA is ≤ 2 days.Among the 302 blood vessels,there are 162 normal blood vessels(53.6%),57 mild stenosis(18.9%),14 moderate stenosis(4.6%),42 severe stenosis(13.9%),and 20 occluded(6.6%),of which MCA M2 There were 7 cases of segmental stenosis.There are significant differences in blood flow velocity parameter(PSV、MFV、EDV)between groups(P<0.05).The critical value of blood flow velocity for TCD in the diagnosing mild stenosis of MCA is PSV>149cm/s(area under the ROC curve,sensitivity,specificity,positive predictive value,negative predictive value of 0.984,93.0 %,97.5%,93.0%,97.5%),MFV>89cm/s(0.968,93.0%,93.8%,84.7%,97.6%).The critical value of blood flow velocity index for mild to moderate stenosis PSV>215cm/s(0.997,100%,98.3%,93.3%,100%),MFV>139cm/s(0.920,85.7%,98.3%,92.3%,96.6%).The critical value of blood flow velocity index for moderate to severe stenosis is PSV>275cm/s(0.910,85.7%,85.7%,94.7%,66.7%),MFV>174cm/s(0.937,90.5%,85.7%,95.0%,75.0%),PSVst/ PSVdis>2.65(0.872、83.3%、100%、100%、66.7%).The spectrum of severe stenosis changes significantly,including eddy currents,turbulence,short arcs,and unclear spectrum envelopes.Diagnosis of chronic occlusion of MCA: There are significant differences between the PSV of MCA,MCA/iACA,and MCA/iPCA on the occluded side and the contralateral side.The PSV of the occluded side MCA is slower than the ipsilateral anterior cerebral artery,posterior artery,and contralateral middle cerebral artery.There was no significant difference in the PI value between the parameters on the occlusion side.Conclusion:(1)TCD has high accuracy in diagnosing MCA stenosis.TCD can accurately distinguish between normal and stenosis MCA,and distinguish different degrees of stenosis.(2)The diagnosis of TCD in the evaluation of MCA mild stenosis is PSV>149cm/s、MFV>89cm/s;the diagnosis of moderate stenosis is PSV>215cm/s、MFV>139cm/s;the diagnosis of severe stenosis is PSV > 274cm/s、MFV>174cm/s、PSVst/PSVdis>2.65.(3)As the degree of vascular stenosis increases,the shape of the spectrum changes more obviously.Is given priority to with frequency window fill in mild stenosis,a few is normal laminar flow spectrum;is given priority to with eddy current in Moderate stenosis,turbulence;eddy currents and turbulence coexist,the upper bound of the spectrum is unclear,and short arcs in Severe stenosis of MCA.4.On-side MCA blood flow rate is significantly slower than the opposite MCA,the same side ACA,PCA,suggesting that the MCA may have extremely severe stenosis or occlusion. |
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