Abstract: Objective To extend our knowledge of the congenital disease, this study attempted to assess the diagnostic value of posterior cerebral circulation in vertebral artery hypoplasia(VAH) detected by color Doppler flow imaging(CDFI), as well as to provide hemodynamic data for posterior circulation ischemia in VAH. Methods Fifty-three patients with vertebral artery hypoplasia and 60 healthy controls confirmed by color Doppler sonography were enrolled into this study. Vertebral artery diameter(VAD), peak systolic velocity(PSV), end diastolic velocity(EDV), resistance index(RI), velocity-time integral(VTI) and heart rate(HR) were measured. Vessel areas and blood flow volume were calculated. Variation of the difference of the results between the case and control groups was analyzed to assess the effect of congenital VA hypoplasia on posterior circulation. Results A comparison between the case and control groups showed that the blood flow of posterior circulation in case group was lower compared with the control group(299.83±58.52) mL/min vs (351.26±49.17) mL/min(P<0.05). The average blood flow of dysplasia side was(47.57±18.41) mL/min. Diastolic velocity was(11.46±3.97) cm/s and the resistance index was(0.78±0.09). There was statistical different between the dysplasia side and the contralateral normal side, and between the case and control groups(P<0.05). Moreover, the posterior circulation flow in the case group was positively correlated with the vertebral artery diameter(R²=0.887 8), and negatively correlated with the resistance index(R²=0.849 4). Conclusion Obviously reduced cerebral blood flow was associated with VAH. In spite of the existence of uninjured side compensation, the total perfusion of posterior circulation was still lower than that of the control group. Color Doppler sonography not only images the congenital morphologic variations of vertebral artery but also evaluates the reduced blood flow of posterior circulation(i.e. posterior circulation ischemia), which might become one of the hallmarks of VAH.

Key words: color Doppler flow imaging, vertebral artery hypoplasia, blood perfusion