ultrasound color doppler technology displays blood flow signals in color, and the pseudocolor code is composed of three basic colors: red, blue, and green. Red represents blood flow directed toward the probe, and blue represents blood flow moving away from the probe. The blood flow velocity is related to the color brightness, with high velocities shown as bright colors and low velocities shown as dark colors. For example, when the blood flow velocity directed toward the probe is low, the signal is dark red, and when the blood flow velocity moving away from the probe is low, the signal is dark blue. If the blood flow velocity is very low, the color signal is weak, and the color is dark, making it difficult to distinguish on the screen.
High-frequency probes can detect calcification points smaller than 1mm in blood vessels, which is useful for diagnosing carotid atherosclerotic occlusive diseases. It can also be used to examine blood flow locally to determine the degree of stenosis, whether clots have detached, whether ulcers have formed, and to prevent cerebral embolism.
It is the best diagnostic method for various arteriovenous fistulas, and when a colorful mosaic ring-shaped spectrum is detected, the diagnosis can be confirmed. For diseases such as carotid aneurysms, abdominal aortic aneurysms, occlusive vasculitis, and chronic lower extremity veins, the use of color ultrasound's high-definition, local amplification, and blood flow spectral analysis can result in a more accurate diagnosis.
Ultrasound color doppler is mainly used for diagnosing the liver and kidneys. The colour flow doppler ultrasound is used as an auxiliary diagnostic tool for differentiating benign and malignant lesions in the abdomen, distinguishing gallbladder cancer from large polyps and severe chronic inflammation, and distinguishing between the bile duct and hepatic artery in disease differentiation.
For small organs, ultrasound color doppler, including handheld vascular doppler ultrasound, is mainly used to clearly diagnose the thyroid, mammary glands, eyes, etc.
Combined with prostate biopsy, various prostate and seminal vesicle diseases can be diagnosed.
It is used to differentiate between benign and malignant tumors and umbilical cord diseases, evaluate fetal heart disease, and assess placental function. It has good diagnostic value for infertility, pelvic varicose veins, and nutrition cell diseases. The use of a vaginal probe has certain advantages over an abdominal probe and is mainly reflected in the following aspects:
It is sensitive to the blood flow of the uterus and ovaries with a high display rate.
It shortens the examination time and obtains accurate Doppler spectra.
It does not require a full bladder.
It is not affected by obesity, abdominal scars, intestinal gas, etc.
Using the top of the probe to search for tender spots of pelvic organs to determine whether the pelvis is adhesion-prone.