What is a color Doppler ultrasound?

​It is usually composed of probes (phased array, linear array, convex array, mechanical fan scan, three-dimensional probe, endoscopic probe, etc.), ultrasonic transmitting/receiving circuit, signal processing and image display. Using ultrasonic Doppler technology and ultrasonic echo principle, it is a device that simultaneously collects blood flow motion, tissue motion information and human organ tissue imaging.

It is used for ultrasound imaging, measurement and blood flow motion information acquisition for clinical ultrasound diagnostic examination. The probe can be passed through the esophagus, in the blood vessel, through the internal tissue of the human body during the operation, and/or used in the fields of ultrasound navigation and the like.

1. Color Doppler ultrasound generally uses autocorrelation technology for Doppler signal processing. The blood flow signal obtained by autocorrelation technology is color-coded and superimposed on the two-dimensional image in real time, that is, color Doppler ultrasound blood flow is formed. streaming images. It can be seen that color Doppler ultrasound (color Doppler ultrasound) not only has the advantages of two-dimensional ultrasound structural images, but also provides rich information on hemodynamics. For “non-invasive angiography”. Its main advantages are:

① It can quickly and intuitively display the two-dimensional plane distribution of blood flow.

②It can display the running direction of blood flow.

③ It is helpful to distinguish between arteries and veins.

④It is helpful to identify vascular lesions and non-vascular lesions.

⑤ Conducive to understanding the nature of blood flow.

⑥ It is convenient to understand the phase and speed of blood flow.

⑦ Shunt and reflux can be found reliably.

⑧ It can quantitatively analyze the origin, width, length and area of blood flow bundles.

2. The related technology used in color Doppler is pulse wave. When the speed of the detected object is too high, the color of the color flow will be wrong, which is obviously inferior to spectral Doppler in quantitative analysis. Today, color Doppler ultrasound instruments have spectral Doppler Le function, that is, color ─ ─ dual function ultrasound.

3. Color Doppler Ultrasound Flow Diagram (CDF), also known as Color Doppler Ultrasound Imaging (CDI), the source of echo information obtained by it is consistent with spectral Doppler, and the distribution and direction of blood flow are displayed in two dimensions. Different speeds are distinguished by different colors. Duplex Doppler ultrasound system, which is a B-mode ultrasound image showing the location of blood vessels. Doppler measures blood flow, and this combination of B-mode and Doppler systems can more precisely locate any given blood vessel.

1. Direction of blood flow In spectral Doppler displays, the direction of blood flow is differentiated with a zero baseline. Those above the zero baseline indicate blood flow toward the probe, and those below the zero baseline indicate blood flow leaving the probe. In CDI, the direction of blood flow is color-coded, with the red or yellow color spectrum indicating blood flow toward the probe (hot color); and the blue or cyan color spectrum indicating blood flow away from the probe (cool color).

2. Vascular distribution CDI shows the blood flow in the vascular lumen, so it belongs to the channel type display, and it cannot show the vascular wall and adventitia.

3. Differentiation of vascular types of cancer nodules CDI can be used to classify the blood vessels of liver cancer nodules. Distinguish it as the blood vessels surrounding the nodule and the arcuate blood vessels to the inner edge of the nodule. Inflow blood vessels of nodules, internal blood vessels of nodules and outflow vessels of nodules, etc.