Medical ultrasonic examination of the working principle and sonar has some similarity, that is, ultrasonic waves emitted into the body, when it meets the interface in the body will be reflected and refracted, and in the human body tissue may be absorbed and attenuation. Because the shape and structure of various human tissues are not the same, so its reflection and refraction and absorption of ultrasound waves to different degrees, doctors are reflected by the instrument through the wave form, curve, or image characteristics to identify them. In addition, combined with anatomical knowledge, normal and pathological changes, can diagnose whether the organs examined are diseased.
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