Doppler principle refers to the phenomenon that ultrasonic waves with a certain frequency are emitted by a probe and reflect when they meet the interface of different tissues or organs. If there is relative motion between the probe and the reflector, the reflection frequency of ultrasonic wave will change due to the motion.
Color Doppler ultrasound examination is widely used, which can be divided into brain, heart, abdominal organs, urinary system, superficial organs, peripheral blood vessels, gynecology, obstetrics and other items. The listed parts are as follows.
Abdominal organs: including liver, gallbladder, pancreas, spleen, kidney, gastrointestinal tract, abdominal blood vessels, adrenal gland, etc.
Urinary color ultrasound:? Including kidney, ureter, prostate, bladder, etc.
Superficial organs: including thyroid, breast, lymph nodes, vaginal ducts, superficial masses, eyes, etc.
Color Doppler ultrasound of peripheral blood vessels: including neck blood vessels and limbs blood vessels.
Gynecological color ultrasound: including uterus, ovary, fallopian tube, pelvic cavity, etc.
The principle of color Doppler ultrasound examination is to use Doppler effect to check blood flow and observe the morphological characteristics of each part in combination with the structure of two-dimensional ultrasound images. The results mainly depend on equipment factors (such as high instrument temperature, poor image quality and performance) and doctors' experience (such as improper probe selection frequency, subjective judgment of ultrasound doctors, etc.). ) and the patient's own conditions (such as obesity, intestinal gas accumulation, poor coordination, inadequate preparation, etc. ).