A Comparative Study Of Hemodynamics Between TCD And CTP In Patients With Cerebral Watershed Infarction

Objective:The study is about the methods of acute cerebral watershed infarction(CWI)hemodynamic evaluation by transcranial Doppler(TCD)and CT perfusion imaging(CTP)control study,which is aiming at exploring the clinical application value of TCD in patients with CWI.Methods:This study prospectively selected patients with acute cerebral watershed infarction admitted to our hospital from June 2015 to July 2017,and underwent transcranial Doppler and CTP examinations.After inclusion of exclusion criteria,a total of 41 patients were included in the study.The general data were recorded,then the difference between the parameters of bilateral cerebral hemisphere CTP and the peak systolic flow velocity(PSV)of the bilateral middle cerebral artery(TCD)were calculated.The criteria for judging hypoperfusion by CTP were that both sides of the affected side and uninjured side were compared,parameters(CBV,CBF,MTT,TTP)had at least one change over 20%.The criterion of low perfusion by TCD is that the difference of systolic velocity between bilateral middle cerebral arteries is greater than 20%.To sum up the results of the examination,SPSS 17 statistical software was used to analyze the consistency of TCD and CTP in judging the perfusion of cerebral watershed infarction,and to explore the diagnostic value of TCD in hemodynamics of acute cerebral watershed infarction.Results:1.CTP low perfusion group and no hypoperfusion group,improper step-down,dehydration cases comparison,the difference was significant,with statistical significance(χ2=5.19,P<0.05);the two groups in age,gender,smoking,hypertension,diabetes mellitus,comparison of arrhythmia and other risk factors,the difference was not statistically significant(P>0.05).2.In the CTP low perfusion group and the non-low-perfusion group,CTP parameters(CBV,CBF,MTT,TTP)bilateral differences and the middle cerebral artery PSV bilateral difference,the comparison between the two groups were statistically significant(P<0.001).3.The study included 41 patients,who were examined by TCD for 21 patients with hypoperfusion and 20 without hypoperfusion.Among them,the number of true positive cases was 16,the number of true negative cases was 18.the number of false positive cases was 5,the number of false negative cases was 2.The positive predictive value[the number of true positive cases÷(the number of true positive cases + the number of false positive cases)* 100%]was 76.19%,the negative predictive value[the number of true negative cases ÷(the number of true negative cases + the number of false negative cases)* 100%] was 90.00%.For low perfusion judgment,the sensitivity of TCD was 88.89%,the specificity was 78.26%,accuracy was 82.93%.[Sensitivity = true positive number /(true positive number + false negative cases)* 100%,Specificity = true negative number/(true negative number + false positive number)* 100%,Accuracy =(true positive number + true negative number)/ total number of cases * 100%].In judging the hypoperfusion of cerebral watershed infarction,there was no significant difference between TCD and CTP(P=0.227),the Kappa value was 0.6595,P<0.001,which was statistically significant,suggesting that TCD and CTP have the consistency in judging the hypoperfusion of cerebral watershed infarction.Conclusion:1.Low blood pressure,low blood volume has a clear correlation between factors and low perfusion of cerebral watershed infarction.2.The change of cerebral blood flow velocity is in good agreement with the change of cerebral blood flow,middle cerebral artery blood flow velocity changes can indirectly reflect the supratentorial hemisphere perfusion blood flow changes.3.The hemodynamic evaluation of transcranial Doppler in patients with cerebral watershed infarction is consistent with that of CT perfusion scan.With CTP as the standard,the sensitivity,specificity and accuracy were high.Because of limitations,some patients are unable to undergo CTP examinations,and TCD can be used as an alternative to assessing cerebral perfusion in bilateral cerebral hemispheres.It is helpful to the clinical early diagnosis of cerebral perfusion and assess the condition,and can provide guidance for treatment.It is worth popularizing and popularizing.