Analysis Of TCD Peak Velocity Time Change In Carotid Artery Stenosis

Objective: This study choosed patients with carotid artery stenosis as the object. Weexplored the transcranial doppler ultrasonography (TCD) spectral characteristics ofthese carotid arteries,and evaluated the value of TCD peak velocity times indiagnosing carotid artery stenosis.Method: We collected196patients who underwent carotid artery CTA and TCD in aweek. The research vessels include bilateral internal carotid artery, middle cerebralartery, vertebral artery and basilar artery.In all cases of CTA confirmed that researchvascular stenosis had a total of281. According to the results of CTA examination,allpatients were divided into three groups: normal control group, mild stenosis group,moderate-severe stenosis group. Blood flow velocity (includeing Vs and Vm),pulsatility index, resistance index and spectral patterns of each arteries was recorded.At the same time, we selected a clear single spectrum as an unit of observation fromeach artery and identified the cardiac cycle starting point (T0), systolic peak velocitypoint (S), diastolic peak velocity point (D), and the end point of cardiac cycle. Afterthat we calculated the peak velocity times (includeing SPT and DPT) and the tworespectively accounted for the entire cardiac cycle ratio (SPT/T, DPT/T).Comparingthe difference between three groups in SPT, DPT, SPT/T, DPT/T.Results:1. In the overall analysis, SPT and SPT/T were higher in moderate-severestenosis group than the other two groups, but there were no difference between thenormal group and mild stenosis group. And we have got consistent results with theoverall analysis of the anterior circulation.In the posterior circulation, SPT only in thesevere stenosis group and the control group were significantly different, but had nosignificant difference in mild stenosis group comparing with the other twogroups.SPT/T had significant difference in the three groups, and increased as thedegree of stenosis.2.DPT, DPT/T were no significant difference between the three groups in the anterior circulation, posterior circulation or the overallanalysis.3.Matched-paired analysis between larger than50%stenosis of unilateralvascular and the contralateral homonymous vessels were paired analysis found that,SPT, SPT/T in larger than50%stenosis side is higher but DPT、DPT/T is smaller. Andthe differences is significant.Conclusion：1.As the indexs of systolic peak velocity time in more than50%stenosisarteries is greater than normal and mild stenosis arteries, the systolic peak velocitytime may become a new index of Intracranial and extracranial vascular stenosis,which is objective and convenient.2.The shortening of diastolic peak velocity timemay have significance when evaluating intracranial and extracranial vascular stenosis.