1.How much is the value of ultrasound examination? Ultrasound is one of the various medical examination techniques, which is characterized by images to reflect the disease, so it belongs to imaging diagnostic techniques, and other diagnostic techniques such as X-ray, CT, MRI, PET, and nuclide are all imaging diagnostic techniques. As the name implies, “imaging” means looking at the morphology of organs and tissues. Ultrasound currently has a maximum resolution of millimeters, so the value of ultrasound is to observe diseases on gross anatomy (as opposed to cellular anatomy, molecular anatomy, etc.). As a simple example, for example, to observe whether a tumor has grown in the liver, which is an anatomical change; for example, nephritis, which is a lesion of the kidney cells, can only be confirmed by blood tests and observation of the liver cells under a microscope, which cannot be checked with ultrasound. If your ultrasound doctor tells you that the child in your belly is lacking iron, zinc or this and that, please don’t believe it, there is no expert in the world who can check molecular diseases with ultrasound instruments. 2.After the ultrasound examination, why do we have to do CT, MRI, nuclear and other examinations? These examinations are all imaging examinations, but each has its own strengths and weaknesses. For example, ultrasound and molybdenum-palladium fluoroscopy are usually needed for common breast tumors because ultrasound can examine most benign tumors and hyperplastic nodules, but some tiny calcified spots will not be shown (because of the diffraction property of sound waves), while molybdenum-palladium film is more sensitive to these tiny calcified spots, but it does not show well for non-calcified benign tumors and hyperplastic nodules, so two kinds of imaging are needed. Therefore, a combination of both imaging examinations is needed. 3.What are the precautions for ultrasound examination? Before ultrasound examination, patients should be prepared according to the specific examination items and contents. For example, patients undergoing hepatobiliary and pancreatic examinations should fast for 6-8 hours to reduce gastrointestinal gas interference with ultrasound and to prevent the gallbladder from contracting due to fasting. For gynecologic and urologic examinations, more water is needed to fill the bladder and push open the bowel to facilitate adequate visualization of the uterus, ovaries and bladder wall. For interventional ultrasound diagnosis or treatment, blood count, bleeding and clotting time should be checked. 4.Is ultrasonography painful and why do we need to apply the “glue”? Ultrasound is a painless test, so there is no need to be nervous or afraid. When doing the ultrasound examination, the doctor will apply some “glue” like drugs on the examination site, don’t worry, this is a coupling agent, it not only has a lubricating effect, but also can avoid cross infection between patients.