van Everdingen K J, van der Grond J, Kappelle L J
Department of Radiology, University Hospital Utrecht, The Netherlands.
J Vasc Surg. 1998 Mar;27(3):479-85. doi: 10.1016/s0741-5214(98)99999-2.
The accuracy of duplex sonography in predicting the degree of an internal carotid artery (ICA) stenosis is decreased when a contralateral high-grade stenosis or occlusion is present. The purpose of this study was to determine whether this overestimation of the stenosis by duplex sonography is associated with an increase in volume flow through the ipsilateral ICA.
Forty-seven patients (89 vessels) with a symptomatic ICA stenosis or occlusion who underwent duplex sonography, intraarterial digital subtraction angiography, and magnetic resonance angiography flow quantification of the ICAs were evaluated.
With the use of peak systolic velocity criteria, duplex overestimated stenoses more frequently (chi2: p = 0.03) in vessels with high volume flow (= mean volume flow in control group + 2 SD (>274 ml/min), 46% overestimation) than in vessels with normal or low volume flow (<274 ml/min, 20% overestimation). A correlation coefficient of 0.75 (p < 0.001) was found between volume flow and peak systolic velocity in the distal ICA, indicating that increased volume flow causes the peak systolic velocity to increase. Compared with volume flow in the control group (mean +/- SD = 198 +/- 38 ml/min), volume flow was increased in vessels with a 0% to 49% stenosis (mean +/- SD = 272 +/- 100 ml/min, p < 0.05) and in vessels with a 50% to 69% stenosis (mean +/- SD = 291 +/- 79 ml/min, p < 0.01) when the contralateral ICA had a 70% to 99% stenosis or occlusion.
Increase in volume flow through the ICA frequently causes overestimation of stenoses in the ICA. Increased volume flow is frequently found in ICAs with a <70% stenosis that are contralateral to ICAs with a >70% stenosis or an occlusion.
当存在对侧高度狭窄或闭塞时，双功超声预测颈内动脉（ICA）狭窄程度的准确性会降低。本研究的目的是确定双功超声对狭窄的这种高估是否与同侧ICA血流量增加有关。
对47例有症状的ICA狭窄或闭塞患者（89条血管）进行了评估，这些患者接受了双功超声、动脉内数字减影血管造影以及ICA的磁共振血管造影血流定量检查。
使用收缩期峰值流速标准时，与正常或低血流量（<274 ml/min，高估20%）的血管相比，高血流量（=对照组平均血流量+2标准差（>274 ml/min），高估46%）的血管中，双功超声更频繁地高估狭窄（χ2：p = 0.03）。在ICA远端，血流量与收缩期峰值流速之间的相关系数为0.75（p < 0.001），表明血流量增加导致收缩期峰值流速增加。与对照组血流量（平均±标准差 = 198 ± 38 ml/min）相比，当对侧ICA有70%至99%狭窄或闭塞时，0%至49%狭窄的血管（平均±标准差 = 272 ± 100 ml/min，p < 0.05）和50%至69%狭窄的血管（平均±标准差 = 291 ± 79 ml/min，p < 0.01）血流量增加。
通过ICA的血流量增加经常导致对ICA狭窄的高估。在对侧ICA有>70%狭窄或闭塞的情况下，<70%狭窄的ICA中经常发现血流量增加。
