Doppler examination is what is usually called ultrasound examination, which includes many items and can examine various diseases of liver, gallbladder, pancreas, spleen, both kidneys, ureter, bladder and prostate, including occupational diseases and congenital diseases. Vascular and cardiac ultrasound examinations can observe whether the blood vessels have thick walls, plaques and thrombi, and whether the size and shape of the heart are enlarged, and whether there is myocardial ischemia, valve regurgitation, valve sclerosis and decreased cardiac function. Ultrasound examination is required for all stages of fetal life. Congenital developmental diseases of the fetus are incomparable to other organ diseases.