Regarding ultrasound examination, I believe many people are very curious about it. Every time they undergo ultrasound examination, they are required to lie in bed, and then the examining physician will probe a scanner like probe around your stomach. Before you fully understand the situation, the examining physician will give you a nearly black and white examination report. Therefore, many people may wonder why the images on the examination sheet I received were still black and white, even though I had an ultrasound examination? Isn't the ultrasound order in full color? Otherwise, what is the difference between ultrasound and B-ultrasound? Below, I will decode why ultrasound images are black and white.
Before discussing ultrasound, we must first understand ultrasound.
With the continuous development of medical technology, physical examination instruments that use ultrasound or X-ray to detect internal organ lesions in the human body have emerged, and B-ultrasound is one of them. B-mode ultrasound imaging is named after the use of brightness modulation mode, also known as two-dimensional grayscale imaging or black and white imaging. Its working principle is to use the reflection time of ultrasonic waves to calculate the density difference on the propagation path through the time it takes for the waves to propagate and reflect back in the human body, and then obtain an image. These images can clearly display various cross-sectional images of various organs and surrounding organs. Due to the rich sense of entity in the images, they are close to the real anatomical structure. Therefore, they are applied to the examination of various organs such as the heart, liver duct, gallbladder, pancreas, etc. during physical examinations. Modern ultrasound Doppler imaging equipment is based on B-mode imaging.
Color Doppler ultrasound is an upgraded version of B-ultrasound, officially known as color Doppler ultrasound diagnostic instrument. Simply put, color Doppler ultrasound uses the color Doppler effect to display blood flow in a certain section of the B-ultrasound technology, adding a vascular flow map. It encodes and detects the reflected (scattered) wave frequency and signal of moving organs or red blood cells in color, with red indicating movement towards the probe, blue indicating movement away from the probe, and green indicating the variability of movement speed. Then, it is overlaid onto a B-ultrasound image to obtain a two-dimensional color blood flow map for imaging.
Therefore, it can be seen that ordinary B-ultrasound can display the morphology and internal structure of lesions, while color ultrasound can detect the blood flow perfusion of these organs, which can better help detect early-stage lesions in various organs.
Many people have the misconception that color ultrasound is necessarily color. Actually, it's not true. The basis of color ultrasound examination still relies on two-dimensional black and white, with the addition of a color Doppler on top of two-dimensional. Simply put, it's blood flow. With blood flow, we call it color ultrasound. This way, it is more high-end and has better resolution. By combining conventional two-dimensional black and white examination with blood flow display, it can help diagnose. The reported image does not add color blood flow colors, so the displayed image is not color, so it looks black and white. However, the report contains descriptions about the blood flow situation.
What types of lesions can be detected by ultrasound?
Various organs in the human body, including the heart, blood vessels, liver, gallbladder, pancreas, spleen, kidneys, ureters, bladder, uterus, ovaries, prostate, seminal vesicles, thyroid gland, breast, subcutaneous soft tissue, etc., can be detected by ultrasound for lesions. Therefore, in daily physical examinations, we particularly need to pay attention to color ultrasound examination.
Is ultrasound examination harmful to the human body?
Does ultrasound examination produce radiation to the human body? In fact, ultrasound has no radiation on the human body. Ultrasound utilizes the principle of ultrasound, and the ability of humans to hear sound is due to the transmission of sound waves. The frequency of sound waves that can be heard by the human ear is between 20Hz-20000Hz, and sound waves above 20000 Hz are called "ultrasonic waves". The simplest example is that B-ultrasound and color ultrasound are often used for prenatal examinations in pregnant women. These types of examinations are not harmful to newborns in the mother's womb, let alone ordinary adults.
Finally, to summarize, color ultrasound is not a color television, so the images are not in color. I hope that from today's popular science knowledge, everyone can understand the working principle of color ultrasound and re evaluate it, so that they can correctly choose and apply it in future examinations!