Martini Ziekenhuis Groningen, Groningen, The Netherlands.
Ultrasound Med Biol. 2012 Aug;38(8):1451-9. doi: 10.1016/j.ultrasmedbio.2012.03.016. Epub 2012 May 12.
The great potential of transcranial Doppler (TCD) as a tool for neuromonitoring is limited by the current parameterization of the signal. This article proposes a set of new parameters that more accurately represents the shape of the waveform and eliminates a number of confounding factors. This set of parameters was tested in 227 patients with ipsilateral carotid artery stenosis and compared with 31 normal subjects recruited at our laboratory. From the TCD waveform, we calculated on a beat-to-beat basis the maximal change in flow velocity at stroke onset (acceleration or acc), the maximal flow velocity during the first 100 ms of systole (sys1) and the maximal flow velocity in the remaining part of systole (sys2). All data were normalized relative to the mean diastolic flow velocity over an interval ranging from 520 till 600 ms after stroke onset (dias@560). For the group with carotid stenosis compared with the normal controls the average ± SD for acc (20.2 ± 9.5 vs. 20.2 ± 6.7; p = 0.98) and sys1 (1.82 ± 0.38 vs. 1.77 ± 0.56; p = 0.35) did not differ significantly. The average ±SD for sys2 (1.94 ± 0.33 vs. 1.50 ± 0.12; p < 0.001), however, was significantly higher in the group with carotid stenosis than in the group of normal subjects. The difference between sys1 and sys2 ("sys1-sys2") was lower in the patient group than in controls (-0.12 ± 0.16 vs. 0.27 ± 0.22; p < 0.001). For the acc, there was a significantly higher variance in the group with stenosis than without (p < 0.001). Of the old parameters, the beat-to-beat mean (37.0 ± 13.1 vs. 41.3 ± 15.9; p = 0.17) and the pulsatility index (PI; 1.00 ± 0.26 vs. 0.91 ± 0.23; p = 0.06) were not significantly different between groups. Graphed together the acc and "sys1-sys2" parameters allowed a clear demarcation of both groups whereas in a graph of the old parameters mean and PI both groups overlapped considerably. In conclusion, the proposed set of new parameters not only has theoretical and practical benefits but also has excellent discriminative power in a group of carotid patients compared with normal controls.
经颅多普勒（TCD）作为神经监测工具具有巨大的潜力，但受到目前信号参数化的限制。本文提出了一组新的参数，这些参数可以更准确地表示波形的形状，并消除许多混杂因素。我们在 227 名同侧颈内动脉狭窄患者中测试了这组参数，并与在我们实验室招募的 31 名正常受试者进行了比较。从 TCD 波形中，我们在逐拍的基础上计算了中风发作时流速的最大变化（加速度或 acc）、收缩期前 100 毫秒的最大流速（sys1）和收缩期其余部分的最大流速（sys2）。所有数据均相对于中风发作后 520 至 600 毫秒间隔内舒张期平均流速进行归一化（dias@560）。与正常对照组相比，颈内动脉狭窄组的平均±标准差（SD）acc（20.2±9.5 与 20.2±6.7；p=0.98）和 sys1（1.82±0.38 与 1.77±0.56；p=0.35）差异无统计学意义。然而，颈内动脉狭窄组的平均±SD sys2（1.94±0.33 与 1.50±0.12；p<0.001）明显高于正常对照组。与对照组相比，患者组的 sys1-sys2 差值（0.12±0.16 与 0.27±0.22；p<0.001）较低。与对照组相比，狭窄组的 acc 方差明显较高（p<0.001）。在旧参数中，逐拍均值（37.0±13.1 与 41.3±15.9；p=0.17）和搏动指数（PI；1.00±0.26 与 0.91±0.23；p=0.06）在两组之间无显著差异。将 acc 和“sys1-sys2”参数绘制成图可以清楚地区分两组，而在旧参数均值和 PI 的图中，两组重叠相当大。总之，与正常对照组相比，本文提出的这组新参数不仅具有理论和实际意义，而且具有出色的判别能力。
