Zierler R E, Phillips D J, Beach K W, Primozich J F, Strandness D E
Department of Surgery, University of Washington School of Medicine, Seattle 98195.
Ultrasound Med Biol. 1987 Aug;13(8):471-6. doi: 10.1016/0301-5629(87)90111-6.
The combination of a B-mode imaging system and a single range-gate pulsed Doppler flow velocity detector (duplex scanner) has become the standard noninvasive method for assessing the extracranial carotid artery. However, a significant limitation of this approach is the small area of vessel lumen that can be evaluated at any one time. This report describes a new duplex instrument that displays blood flow as colors superimposed on a real-time B-mode image. Returning echoes from a linear array of transducers are continuously processed for amplitude and phase. Changes in phase are produced by tissue motion and are used to calculate Doppler shift frequency. This results in a color assignment: red and blue indicate direction of flow with respect to the ultrasound beam, and lighter shades represent higher velocities. The carotid bifurcations of 10 normal subjects were studied. Changes in flow velocities across the arterial lumen were clearly visualized as varying shades of red or blue during the cardiac cycle. A region of flow separation was observed in all proximal internal carotids as a blue area located along the outer wall of the bulb. Thus, it is possible to detect the localized flow patterns that characterize normal carotid arteries. Other advantages of color-flow imaging include the ability to rapidly identify the carotid bifurcation branches and any associated anatomic variations.
B 型成像系统与单距离选通脉冲多普勒血流速度探测器（双功能扫描仪）相结合，已成为评估颅外颈动脉的标准非侵入性方法。然而，这种方法的一个显著局限性是在任何给定时间内能够评估的血管腔面积较小。本报告介绍了一种新型双功能仪器，它能将血流以颜色叠加在实时 B 型图像上的形式显示出来。来自线性换能器阵列的回波会持续进行幅度和相位处理。相位变化由组织运动产生，并用于计算多普勒频移。这就产生了一种颜色赋值：红色和蓝色表示血流相对于超声束的方向，较浅的色调代表较高的速度。对 10 名正常受试者的颈动脉分叉进行了研究。在心动周期中，动脉腔内血流速度的变化清晰地显示为红色或蓝色的不同色调。在所有近端颈内动脉中均观察到一个血流分离区域，表现为位于球部外壁的蓝色区域。因此，有可能检测到表征正常颈动脉的局部血流模式。彩色血流成像的其他优点包括能够快速识别颈动脉分叉分支以及任何相关的解剖变异。
