Alexandrov A V, Brodie D S, McLean A, Hamilton P, Murphy J, Burns P N
Neurovascular Doppler Laboratory, Sunnybrook Health Science Center, University of Toronto, Canada.
Stroke. 1997 Feb;28(2):339-42. doi: 10.1161/01.str.28.2.339.
Recent observations from the North American Symptomatic Carotid Endarterectomy Trial (NASCET) questioned the reliability of peak systolic velocity (PSV) criteria for grading carotid stenosis. We compared PSV and angiographic measurements at our center together with known physiological relationships to investigate the accuracy of ultrasound.
Consecutive patients who underwent both color-coded duplex ultrasound and intra-arterial digital subtraction angiography were studied. PSV was determined with angle correction at the site of the tightest internal carotid artery narrowing. Carotid stenosis was measured on angiograms with the North American (N) and common carotid (C) methods. Variables for the stepwise multiple linear regression analysis were selected from an axisymmetrical flow model.
Eighty bifurcations were imaged in 40 patients. PSV did not exceed 140 cm/s in normal vessels. In diseased arteries, PSV increased proportionally with increasing stenosis and decreased to 0 cm/s at occlusion. In stepwise selection of polynomial terms, the linear, quadratic, and cubic correlations of .38, .17, and .22 for N and .45, .24, and .03 for C were found to be significant (P < .02). When only stenosed vessels were evaluated, PSV increase was found with greater scatter for the N measurement: r2 = .73 for N and r2 = .85 for C (n = 50; P = .03 for the difference between two correlated correlation coefficients).
At our laboratory PSV consistently correlates well with N and C angiographic measurements, as determined with a simple flow model. The complex nature of these correlations and greater variability of the N measurement should be taken into account when data from different centers are compared.
北美症状性颈动脉内膜切除术试验（NASCET）最近的观察结果对用于颈动脉狭窄分级的收缩期峰值流速（PSV）标准的可靠性提出了质疑。我们在本中心比较了PSV与血管造影测量结果以及已知的生理关系，以研究超声检查的准确性。
对连续接受彩色编码双功超声和动脉内数字减影血管造影的患者进行研究。在颈内动脉最狭窄处进行角度校正后测定PSV。采用北美（N）法和颈总动脉（C）法在血管造影上测量颈动脉狭窄程度。从轴对称血流模型中选择逐步多元线性回归分析的变量。
40例患者共对80个分叉进行了成像。正常血管中PSV不超过140 cm/s。在病变动脉中，PSV随狭窄程度增加而成比例增加，在闭塞时降至0 cm/s。在多项式项的逐步选择中，发现N法的线性、二次和三次相关性分别为0.38、0.17和0.22，C法分别为0.45、0.24和0.03，差异有统计学意义（P < 0.02）。仅评估狭窄血管时，发现N测量法的PSV增加更为分散：N法的r2 = 0.73，C法的r2 = 0.85（n = 50；两种相关系数之间的差异P = 0.03）。
在我们实验室，根据简单血流模型测定，PSV与N法和C法血管造影测量结果始终具有良好的相关性。比较不同中心的数据时，应考虑这些相关性的复杂性以及N测量法的更大变异性。
