Kohler T R, Langlois Y, Roederer G O, Phillips D J, Beach K W, Primozich J, Lawrence R, Nicholls S C, Strandness D E
Department of Surgery, University of Washington School of Medicine, Seattle 98195.
Ultrasound Med Biol. 1987 Oct;13(10):637-42. doi: 10.1016/0301-5629(87)90061-5.
The variability of four carotid artery frequency parameters used for classifying disease with duplex scanning was prospectively studied. Forty-eight patients (94 patent carotid arteries) were each examined by two technologists. Measured parameters were the peak systolic frequency (PSF) and the first zero slope from the common carotid artery, and the PSF and end diastolic frequency (EDF) from the internal carotid artery. Measurements from all the examinations were made twice by each technologist. Interobserver, intraobserver, and interpatient variability in measurement of the first zero slope was so great that we have abandoned its use. Measurement of variability for PSF and EDF was much less (correlation coefficients 0.68 to 0.92). These parameters were measured with sufficient precision to warrant their continued use for important decision steps in classifying carotid artery disease. Interpatient differences in PSF sufficient to cause disagreement regarding the hemodynamic significance of carotid disease occurred in only three instances. In each of these cases the differences were due to examination technique (failure to identify a very distal internal carotid artery stenosis, difficulty distinguishing between a kink and a stenosis, and failure to recognize an improper Doppler angle). We conclude that the variability of PSF and EDF is within clinically acceptable levels and is mainly due to examination technique rather than measurement of waveform parameters or changes in patient hemodynamics.
我们前瞻性地研究了用于双功扫描疾病分类的四个颈动脉频率参数的变异性。48名患者（94条颈动脉通畅）由两名技术人员分别进行检查。测量参数包括颈总动脉的收缩期峰值频率（PSF）和首个零斜率，以及颈内动脉的PSF和舒张末期频率（EDF）。每位技术人员对所有检查的测量均进行两次。首个零斜率测量中的观察者间、观察者内和患者间变异性非常大，以至于我们已不再使用该参数。PSF和EDF的变异性测量则小得多（相关系数为0.68至0.92）。这些参数的测量精度足以保证在颈动脉疾病分类的重要决策步骤中继续使用它们。仅在三例中出现了PSF的患者间差异足以导致对颈动脉疾病血流动力学意义产生分歧。在每一例中，差异均归因于检查技术（未能识别非常远端的颈内动脉狭窄、难以区分扭结和狭窄以及未能识别不当的多普勒角度）。我们得出结论，PSF和EDF的变异性在临床可接受范围内，且主要归因于检查技术，而非波形参数测量或患者血流动力学变化。
