Hathout G, Nayak N, Abdulla A, Huang J
Ultraschall Med. 2015 Aug;36(4):362-8. doi: 10.1055/s-0034-1385070. Epub 2014 Sep 9.
A previously described Doppler parameter, the sonographic NASCET index (SNI), was derived to be more directly analogous to the North American Symptomatic Carotid Endarterectomy Trial (NASCET) methodology for assessing carotid artery stenosis. However, this index does not account for complex changes affecting the Doppler waveform. We propose a revised SNI (rSNI) in an effort to improve predicting carotid stenosis.
25 carotid bifurcations with stenoses ranging from 40 - 92 % were analyzed. For each vessel, the rSNI and original SNI were calculated. The peak systolic velocity (PSV), rSNI, and original SNI were correlated with angiography using linear regression analysis and relative accuracies were compared at two thresholds.
A correlation between rSNI and angiography was found to be significantly better than that between PSV or internal carotid artery-common carotid artery (ICA-CCA) peak velocity ratio and angiography (r² = 0.47 vs. 0.22; r² = 0.47 vs. 0.16). The accuracy of PSV in predicting high-grade stenosis was 68% and 72%, compared with 80% and 88% for rSNI, at each of two thresholds. The original SNI better correlated with angiography compared to the rSNI (r² = 0.55 vs. 0.47), but with slightly lower accuracy in predicting high-grade stenosis (76% vs. 80%).
The revised SNI correlates more closely with angiographic stenosis than either the PSV or the ICA-CCA ratio, and is more accurate in predicting high-grade stenosis. However, it is overall comparable to the original SNI, suggesting that the previously unaccounted for effects over the remainder of the cardiac cycle do not significantly improve the ability to sonographically predict significant stenosis.
先前描述的一种多普勒参数，即超声NASCET指数（SNI），其推导目的是使其更直接类似于北美症状性颈动脉内膜切除术试验（NASCET）评估颈动脉狭窄的方法。然而，该指数未考虑影响多普勒波形的复杂变化。我们提出一种修订后的SNI（rSNI），以努力改善对颈动脉狭窄的预测。
分析了25个狭窄程度在40%-92%之间的颈动脉分叉处。对每个血管计算rSNI和原始SNI。使用线性回归分析将收缩期峰值速度（PSV）、rSNI和原始SNI与血管造影进行相关性分析，并在两个阈值下比较相对准确性。
发现rSNI与血管造影之间的相关性显著优于PSV或颈内动脉-颈总动脉（ICA-CCA）峰值速度比与血管造影之间的相关性（r² = 0.47对0.22；r² = 0.47对0.16）。在两个阈值中的每一个阈值下，PSV预测重度狭窄的准确率分别为68%和72%，而rSNI为80%和88%。与rSNI相比，原始SNI与血管造影的相关性更好（r² = 0.55对0.47），但在预测重度狭窄时准确性略低（76%对80%）。
修订后的SNI与血管造影狭窄的相关性比PSV或ICA-CCA比值更密切，并且在预测重度狭窄方面更准确。然而，它总体上与原始SNI相当，这表明在心动周期其余部分先前未考虑的影响并未显著提高超声预测显著狭窄的能力。
