Evaluation Of Anterior Circulation Ischemia By Ultrasonic Measurement Of Internal Carotid Artery BHI

Objective To explore the cerebrovascular reserve capacity in patients with unilateral anterior cerebral circulation disorder by high frequency color Doppler flow imaging(CDFI)combined with breath holding test.Methods 30 patients with unilateral anterior cerebral circulation disorder were selected,all the patients were confirmed by MR.The diameter and hemodynamic parameters of internal carotid artery(ICA)were measured by CDFI,After the subjects underwent CDFI,the breath-holding test was performed and diameter and hemodynamic parameters were measured again The hemodynamic parameters include systolic peak flow velocity(Vs),end diastolic blood flow velocity(Vd),mean blood flow velocity(Vm),pulsatility index(PI),resistance index(RI).Blood flow volume(Q)and breath-holding index(BHI)was calculated.The datas were compared before and after breath,and the correlation between BHI and carotid artery blood flow under basal conditions was analyzed.Results There was no significant difference in the diameter of internal carotid artery before and after breathing(P>0.05).Blood flow velocity(including Vs,Vd and Vm)increased while PI and RI decreased,there was significant difference in the variation of the hemodynamic parameters before and after breath(P<0.05);The BHI of obstacle side ICA was 0.83 ±0.13 in the disorder group,and the BHI of the contralateral side was 1.03±0.17,and was BHI =1.25± 0.19 in normal control group.There were significant difference between the two groups(P<0.05).And there was a positive correlation between carotid artery blood flow and BHI(r=0.494,P<0.05).Conclusion The blood flow of internal carotid artery was positively correlated with BHI,and the BHI of ipsilateral internal carotid artery in patients with unilateral anterior circulation disorder was significantly lower than that of normal people,which showed that the function of cerebral vascular reserve decreased,and the compensatory function of contralateral cerebrovascular was lower than that of normal people.Ultrasonic detection of internal carotid arterial blood flow BHI may be important for predicting anterior circulation disorder.