What is the difference between color Doppler ultrasound, two-dimensional ultrasound and M-mode ultrasound?

It's all ultrasonic display. Two-dimensional ultrasound is what we usually call B-ultrasound, black-and-white ultrasound, which is called B-ultrasound diagnostic instrument in medicine. Brightness modulation ultrasound, commonly known as black-and-white ultrasound instrument, displays two-dimensional gray-scale cross-sectional images, that is, displays anatomical sections in black-and-white images according to different tissue densities on the ultrasound screen. Two-dimensional ultrasound is the main part of ultrasound examination. What we call color Doppler ultrasound is actually called color blood flow imaging. It is a method to observe the velocity, direction and nature of blood flow in blood vessels. It is based on three basic colors, red, blue and green, and is color coded. Generally, the probe facing the probe is red and the probe facing the back is blue. Doctors judge whether the patient's blood flow is abnormal according to the normal blood flow, not the black and white color as most people say on TV. For example, blue or no color is abnormal where blood vessels should be red, and doctors will look for reasons according to their performance. M-mode ultrasound is generally only used for the heart. M-mode activity is a distance-time curve, which records the activity of the heart wall and the activity curve of the valve in the heart. Modern machines integrate the three, that is, we can see the two-dimensional heart structure and M-shaped activity curve, and we can also see the direction, speed and nature of blood flow in the heart according to color blood flow imaging. Plus (Doppler), they can also measure blood flow velocity and pressure according to the flow velocity. Now let's do the cardiac ultrasound together.