Ultrasound is a non-invasive, radiation-free, highly repeatable and practical examination means, which is very widely used clinically and can be used to examine several organs of the whole body, commonly in the following areas: 1. cardiovascular system: such as heart structure, neck vessels, arteries and veins of the limbs; 2. superficial organs: such as parotid gland, submandibular gland, thyroid gland, cervical lymph nodes, breast gland, axillary lymph nodes, subcutaneous swellings, etc.; 3. muscle Bone: such as muscle, tendon, fracture, cartilage injury, chondritis, bone tumor, periarticular structures, nerve injury, etc.; 4, digestive system: such as liver, bile, pancreas, spleen and abdominal cavity, etc., to understand the presence of benign and malignant tumors of the liver and pancreas, the presence of bile ducts, gallbladder stones, etc.; 5, urinary and reproductive system: such as both kidneys, ureter, bladder, prostate and testes, epididymis, to understand the presence of urinary stones and tumors, etc. 6, gynecology: such as uterus, ovaries, fallopian tubes, vagina and vulva, etc., to understand the presence of uterine fibroids, adenomyosis, uterine cavity occupancy, genital tract malformations, adnexal masses, and malignant tumors of the uterus, ovaries, fallopian tubes, etc., and also to monitor follicular development and ovulation; 7, obstetrics: to understand the number of fetuses, embryos and fetal growth and development, screen fetuses for malformations, observe the amount of amniotic fluid, placenta The placenta can also be monitored.