Study On The Diagnostic Value Of Evaluating Vertebral Artery Origin Stenosis With Hemodynamic Parameters

Objectives To investigate the clinical value of ultrasonography in diagnosing vertebral artery origin stenosis with hemodynamic parameters and to analyse focusly the diagnostic value of acceleration time found in ipsilateral intervertebral artery.Methods 77 cases with vertebral artery origin stenosis were found by ultrasonography.All the results were confirmed by other imaging tests including CT angiography(CTA),MR angiography(MRA)or Digital subtraction angiography(DSA).These cases were considered to be stenosis group.There were 172 cases without abnormalities by carotid artery ultrasonography,called healthy group.All the hemodynamic parameters were recorded including the peak systolic velocities(PSV1),end diastolic velocity(EDV1),resistance index(RI1)of the narrowest spot of the vertebral artery origin,the PSV,EDV,RI and acceleration time(AT)of ipsilateral intervertebral artery,PSV0 and AT0 of contralateral intervertebral artery in stenosis group,PSVa and ATa of intervertebral artery in healthy group.77 cases in stenosis group were also divided into nagative group(stenosis <50%)and positive group(stenosis ?50%).The hemodynamic parameters were analysed and the ROC curve was calculated to evaluate diagnostic value of the parameters as the diagnosis of?50% stenosis was treated as a criteria.Results(1)53 positive cases and 24 negative cases were diagnose by ultrasonography,and there were 3 false-positive cases and 5 false-negative cases in ultrasonography diagnosis.The diagnostic sensitivity,specificity,accuracy and Kappa value of ultrasonography were 90.9 %,86.4 %,89.6 % and 0.752 respectively.The diagnosis of ultrasonography and CTA(or MRA,DSA)had closely correlation.(2)The acceleration time of ipsilateral intervertebral artery in the stenosis group was longer than that in the healthy group,and the difference was statistically significant.(3)With simple correlation analysis,it was concluded that there was a strong correlation between PSV1 and?AT(r=0.61,P< 0.01).(4)AT in the positive group was longer than that in the negative group,and the difference was statistically significant.The area under the ROC curve of PSV?EDV and AT/AT0 was 0.714(95%CI:0.599?0.812),0.677(95%CI:0.560?0.780)and 0.760(95%CI:0.648? 0.850)respectively.It was illustrated that their diagnosis value was limited as they were all<0.90.The area under the ROC curve of PSV1 and AT was 0.971(95%CI:0.905?0.996)and 0.905(95%CI:0.816?0.961)respectively.It was showed that their diagnosis value was high as they were all>0.90.In addition,the difference between the area under the ROC curve of PSV1 and AT was about 0.066,and the Z statistic was 1.848,P =0.065,which indicateed that the diagnostic value of PSV1 was higher than that of AT,but the difference was not statistically significant.(5)With the diagnosis of 50% stenosis as standard,the area under the ROC curve of AT Was 0.90.Its diagnostic threshold value was 0.059 s,and the diagnostic sensitivity and specificity were 83.93% and 95% respectively.With the diagnosis of 70% stenosis as standard,the area under the ROC curve of AT Was 0.885.Its diagnostic threshold value was 0.084 s,and the diagnostic sensitivity and specificity were 93.75%and 71.67% respectively.Conclusion The results showed that the acceleration time was useful in diagnosing of vertebral artery origin stenosis.The acceleration time could accurately and dynamically reflect the perfusion of blood flow in the remote area,and its prolongation was closely related to the stenosis of the proximal area.This study may provided a theoretical basis for the diagnosis of vertebral artery origin stenosis with acceleration time of intervertebral artery.