椎动脉发育不全和局限性狭窄的经颅多普勒评价

Transcranial Doppler ultrasonographic evaluation of vertebral artery hypoplasia and focal artery stenosis

目的以CT血管造影（CT angiography, CTA）检查结果作为标准，探讨经颅多普勒（transcranial Doppler, TCD）对椎动脉发育不全（vertebral artery hypoplasia, VAH）和局限性椎动脉狭窄（focal vertebral artery stenosis, fVAS）的诊断价值。 方法纳入连续完成TCD和CTA检查的患者，根据CTA结果分为正常组、VAH组和fVAS组。TCD参数包括平均血流速度（mean flow velocity, MFV）、收缩期峰值血流速度（peak systolic velocity, PSV）、搏动指数（pulsatility index, PI）、阻力指数（resistance index, RI）和不对称指数（asymmetry index, AI），分别进行组间比较。采用受试者工作特征（receiver operator characteristic, ROC）曲线评价TCD参数诊断VAH和fVAS的敏感性和特异性。 结果共纳入405例患者，正常组278例（68.6%），VAH组75例（18.5%），fVAS组52例（12.8%）。各组间受累侧（正常组受累侧定义为右侧椎动脉）MFV、PSV、PI和RI之间均存在显著性差异。VAH组血流速度最慢，fVAS组血流速度最快，其他参数具有相同的趋势。各组间非受累侧MFV和PSV存在显著性差异，VAH组血流速度明显增快，fVAS组血流速度略增快，增快幅度小于VAH组。各组间AI存在显著统计学差异，可作为诊断VAH的指标（曲线下面积为0.78，95%可信区间0.72～0.84；P〈0.001）。以AI〉33.7%作为截断值诊断VAH的敏感性为74.7%，特异性为68.7%。 结论应用TCD评价椎动脉时注意鉴别VAH和fVAS。AI〉33.7%可作为诊断VAH的参考指标。

ObjectiveTo investigate the diagnostic values of transcranial Doppler ultrasonography （TCD） for vertebral artery hypoplasia （VAH） and focal vertebral artery stenosis （fVAS） with CT angiography （CTA） finding as a standard. MethodsConsecutive patient who underwent TCD and CTA were included. According to the findings of CTA, they were divided into 3 groups： a normal group, a VAH group, and a fVAS group. The TCD parameters included the mean flow velocity （MFV）, peak systolic velocity （PSV）, pulsatility index （PI）, resistance index （RI） and asymmetry index （AI）, and they were compared among the groups, respectively. The receiver operator characteristic （ROC） curves were used to evaluate the sensitivity and specificity of TCD parameters for diagnosis of VAH and fVAS. ResultsA total of 405 patients were enrolled, including 278 （68.6%） in the normal group, 75 （18.5%） in the VAH group, and 52 （12.8%） in the fVAS group. There were significant differences in MFV, PSV, PI, and RI on the affected sides among different groups （the affected side in the normal group was defined as the right side）. The blood flow velocity in the VAH group was the slowest, and that in the fVAS group was the fastest. Other parameters had the same trend. There were significant differences in MFV and PSV on the unaffected side among different groups. The blood flow velocity in the VAH group was significantly faster, the fVAS group was slightly faster, and the fVAS group was less than the VAH group. There were significant differences in AI among different groups, and it could be used as an indicator for diagnosis of VAH （the area under the curve 0.78, 95% confidence interval 0.72-0.84; P〈0.001）. With the AI 〉33.7% as a cut-off value, the sensitivity and specificity of VAH diagnosis were 74.7% and 68.7%. ConclusionsAttention should be paid to identifying VAH and fVAS when using TCD for evaluation of vertebral artery. AI 〉33.7% can be used as a reference index for diagnosis of VAH.