分析椎动脉椎间段血流动力学参数变化，探讨其评估椎动脉颅内段狭窄性病变的效能及可行性。

回顾性连续纳入2019年1月至2022年9月于苏州大学附属第一医院行颈部血管超声检查且经CT血管造影（CTA）和（或）数字减影血管造影（DSA）证实有椎动脉颅内段不同程度狭窄或闭塞者279例作为研究组，并纳入同期行颈部血管超声且结果未见明显异常的98例健康体检者作为对照组。根据椎动脉颅内段狭窄程度将研究组分为轻度狭窄组74例、中度狭窄组36例、重度狭窄位于分出小脑后下动脉（PICA）后组（重度狭窄-PICA后组）31例、重度狭窄位于分出PICA前组（重度狭窄-PICA前组）46例、闭塞位于分出PICA后组（闭塞-PICA后组）48例及闭塞位于分出PICA前组（闭塞-PICA前组）44例。各组患者均应用颈部血管超声测量患侧及健侧椎动脉椎间段的血流参数，包括椎动脉直径（VAD）、收缩期峰值流速（PSV）、舒张期末流速（EDV）、阻力指数（RI）。比较各组双侧椎动脉椎间段各血流参数的差异；计算EDV比值（患侧EDV/健侧EDV），并对对照组右侧与各研究组患侧相邻狭窄程度两组的椎间段血流动力学参数进行比较；应用ROC曲线分析各参数诊断椎动脉颅内段狭窄性病变的敏感度、特异度、准确性，并确定最佳诊断界值；采用Spearman相关分析颅内段严重狭窄程度与后循环缺血性卒中的相关性。

各组两侧椎间段VAD、PSV、EDV、RI比较，中度及以下狭窄各组中各参数差异均无统计学意义（P均>0.01），而重度及以上狭窄各组中，各参数差异均有统计学意义（P均<0.01）。研究组患侧及对照组右侧相邻两组椎间段血流参数比较，中度及以下狭窄各组中，除对照组与轻度狭窄组EDV外，余各参数差异均无统计学意义（P均>0.01）；而中度及以上狭窄各组中，除中度狭窄组与重度狭窄组PSV外，余各参数差异均有统计学意义（P均<0.01）。ROC曲线分析显示，EDV及EDV比值诊断重度狭窄的曲线下面积（AUC）分别为0.898（95%CI：0.857~0.931）、0.943（95%CI：0.909~0.967），最佳截断值分别为11.00 cm/s、0.69；EDV及EDV比值诊断闭塞-PICA后的AUC分别为0.917（95%CI：0.882~0.944）、0.903（95%CI：0.868~0.933），最佳截断值分别为9.00 cm/s、0.56；EDV及EDV比值诊断闭塞-PICA前的AUC分别为0.983（95%CI：0.964~0.993）、0.987（95%CI：0.969~0.996），最佳截断值分别为2.00 cm/s、0.20。椎动脉颅内段重度狭窄及以上各组中，狭窄程度与后循环缺血性卒中呈正相关关系（r_s=0.227，P=0.0003）。

颈部血管超声测量椎动脉椎间段各血流动力学参数对颅内段重度狭窄及闭塞具有较高的诊断效能，并能判断闭塞部位与PICA的毗邻关系，为临床治疗及预后的判断提供参考。

To analyze hemodynamic parameters of the intervertebral segment of the vertebral artery and investigate the efficacy and feasibility of using these hemodynamic parameters to assess stenotic lesions in the intracranial segment.

A total of 279 consecutive patients who underwent carotid ultrasound, computed tomography angiography (CTA), and/or digital subtraction angiography (DSA) and exhibited varying degrees of stenosis or occlusion in the intracranial segment of the vertebral artery between January 2019 and September 2022 at the First Affiliated Hospital of Suzhou University were included as a study group. Furthermore, 98 healthy individuals who underwent carotid ultrasound during the same period were included as a control group. The study group was categorized based on the degree of intracranial vertebral artery stenosis into the following groups: 74 cases of mild stenosis, 36 cases of moderate stenosis, 31 cases of severe stenosis occurring after the posterior inferior cerebellar artery (PICA) (severe stenosis-post-PICA group), 46 cases of severe stenosis occurring before the PICA (severe stenosis-pre-PICA group), 48 cases of occlusion occurring after the PICA (occlusion-post-PICA group), and 44 cases of occlusion occurring before the PICA (occlusion-pre-PICA group). Hemodynamic parameters, comprising vertebral artery diameter (VAD), peak systolic velocity (PSV), end diastolic velocity (EDV), and resistance index (RI), were assessed in all groups. Variations in these parameters between the two sides of the vertebral artery segment were analyzed among the groups. The EDV ratio (EDV on the affected side divided by EDV on the healthy side) was computed. A comparison was made between the right side of the healthy control group and the ipsilateral adjacent stenotic side of each study group concerning the hemodynamic parameters of the intervertebral segment of the vertebral artery. The sensitivity, specificity, and accuracy of each parameter in diagnosing intracranial vertebral artery stenosis were calculated using receiver operating characteristic (ROC) curves, and the cutoff values were determined. Spearman correlation analysis was used to analyze the correlation between the degree of severe intracranial stenosis and posterior circulation infraction.

In the comparison of the parameters of the vertebral artery on both sides of each group, no statistically significant differences were observed in VAD, PSV, EDV, or RI (P>0.01 for all) in groups with moderate or less stenosis. However, in groups with severe stenosis or above, statistically significant differences were observed in all of these parameters (P<0.01 for all). Comparison of the parameters between the affected side of the study group and the right intervertebral segment of the control group revealed that among groups with moderate or less stenosis, statistically significant differences were observed only in EDV between the control group and the mild stenosis group, while no significant differences were found in the remaining parameters (P>0.01 for all). Conversely, among groups with moderate stenosis or above, statistically significant differences were observed in all parameters except for PSV between the moderate stenosis group and the severe stenosis group (P<0.01 for all). ROC curve analysis revealed that the area under the curve (AUC) of EDV and EDV ratio in diagnosing severe stenosis was 0.898 (95% confidence interval [CI]: 0.857~0.931) and 0.943 (95%CI: 0.909~0.967), with optimal cutoff values of 11.00 cm/s and 0.69, respectively. For diagnosing occlusion-post-PICA, the AUC of EDV and EDV ratio was 0.917 (95%CI: 0.882~0.944) and 0.903 (95%CI: 0.868~0.933), with optimal cutoff values of 9.00 cm/s and 0.56, respectively. In diagnosing occlusion-pre-PICA, the AUC of EDV and EDV ratio was 0.983 (95% CI: 0.964~0.993) and 0.987 (95% CI: 0.969~0.996), with optimal cutoff values of 2.00 cm/s and 0.20, respectively. In severe intracranial stenosis of the vertebral artery and above groups, the degree of stenosis was positively correlated with posterior circulation infraction (r_s=0.227, P=0.0003).

Carotid ultrasound measurements of hemodynamic parameters in the intracranial vertebral artery segment exhibit enhanced diagnostic accuracy for severe stenosis and occlusion and facilitate the identification of the spatial relationship between the occlusion site and the PICA, thus offering valuable references for clinical treatment decisions and prognosis assessments.