Hayes A C, Johnston K W, Baker W H, Kupper C, Poole M A, Keagy B, Burnham S
Department of Surgery, Loyola University Medical Center, Maywood, IL 60153.
Surgery. 1988 Jan;103(1):19-23.
Continuous-wave Doppler frequency analysis is one standard of noninvasive evaluation for stenotic carotid disease. Interpretation is most commonly based on frequency recorded at the site of stenosis. If flow velocity is increased because of contralateral disease, this criterion may overstate the degree of stenosis. To investigate this, three centers contributed 167 patients to a study of carotid Doppler frequency analysis. Each patient underwent bilateral carotid studies by a standard protocol with use of continuous-wave 5 MHz Doppler probe. There were 309 patent and 25 occluded internal carotids seen on subsequent angiographs. Each patient side was categorized by the severity of ipsilateral disease (less than 45%, 45% to 70%, 71% to 99%, occlusion) and then subgrouped by contralateral disease. For all carotid arteries, the optimal peak frequency to detect 45% or more stenosis was 5500 Hz, with an overall accuracy of 92.2%. Within the three classifications of ipsilateral stenosis, a trend was noted that related increasing peak frequency to greater degrees of contralateral disease. This was most apparent when the contralateral internal carotid artery was occluded. Of all false-positive errors, 43% were accounted for by this subset that represented 15% of the total population. For the 25 patients with occlusion opposite a stenosis, the 5500 Hz cutoff of Doppler peak frequency yielded only 76% accuracy; an ROC curve showed that a cutoff value of 8500 Hz improved overall accuracy to 92% for these patients. By applying two cutoff criteria--5500 Hz for those with patent contralateral internal carotids and 8500 Hz for those in whom a contralateral Doppler signal was not detected--the overall accuracy for all patients improved to 93.3%. It is concluded that contralateral occlusion affects Doppler peak frequency by increasing the velocity in the companion carotid artery, whereas severe contralateral stenosis did not result in a consistent pattern of increased velocity.
连续波多普勒频率分析是评估颈动脉狭窄疾病的一种无创标准。解读通常基于在狭窄部位记录的频率。如果由于对侧疾病导致血流速度增加，该标准可能会高估狭窄程度。为了对此进行研究，三个中心为一项颈动脉多普勒频率分析研究贡献了167例患者。每位患者均按照标准方案使用5兆赫连续波多普勒探头进行双侧颈动脉检查。随后的血管造影显示有309条颈内动脉通畅，25条闭塞。每位患者的一侧根据同侧疾病的严重程度（小于45%、45%至70%、71%至99%、闭塞）进行分类，然后再根据对侧疾病进行亚组分类。对于所有颈动脉，检测45%或更高狭窄程度的最佳峰值频率为5500赫兹，总体准确率为92.2%。在同侧狭窄的三种分类中，注意到一种趋势，即峰值频率增加与对侧疾病程度加重有关。当对侧颈内动脉闭塞时，这种情况最为明显。在所有假阳性错误中，43%是由这一占总人口15%的亚组造成的。对于25例对侧狭窄处有闭塞的患者，多普勒峰值频率的5500赫兹临界值仅产生76%的准确率；一条ROC曲线显示，对于这些患者，8500赫兹的临界值将总体准确率提高到了92%。通过应用两个临界标准——对侧颈内动脉通畅的患者为5500赫兹，未检测到对侧多普勒信号的患者为8500赫兹——所有患者的总体准确率提高到了93.3%。得出的结论是，对侧闭塞通过增加伴行颈动脉的血流速度影响多普勒峰值频率，而严重的对侧狭窄并未导致血流速度增加的一致模式。
