There are many items that can be examined by ultrasound, but some parts of the body are highly sensitive to ultrasound and some are less sensitive. Areas with high sensitivity for routine examinations include the heart, pericardium, liver, gallbladder, spleen, pancreas, kidneys, ureter, bladder, testes, epididymis, uterus, ovaries, fetus, thyroid, breast, submandibular gland, parotid, eye, superficial soft tissue, chest wall, abdominal wall, superficial lymph nodes, arteries and veins of the extremities, and arteries and veins of the neck. The areas with poor sensitivity are gastrointestinal, seminal glands, adrenal glands, abdominal large vessels, deep lymph nodes, muscles, bones and joints, peripheral nerves, lungs, and cranial brain. Although the sensitivity of conventional ultrasound is poor, it can still make certain diagnosis with the help of other external forces, like fluid, cyst, stone, calcification and other pathological changes, the sensitivity, specificity and accuracy of ultrasound examination are very high. In addition, color ultrasound can also be applied to the functional determination of certain parts, including follicle monitoring of fetal growth, fetal development, gallbladder contraction function, bladder reserve function, heart function detection, etc., as well as under the guidance of interventional ultrasound, pathological diagnosis of certain lesions can be made through puncture biopsy, and it can be said that color ultrasound examination is omnipotent and omnipresent.