Ultrasonography
Ultrasonography is the use of high frequency sound waves to generate an image. A small instrument at the end of a cable (called a transducer) is placed on the patient. The ultrasound equipment collects reflected "echoes" and uses them to generate a viewable image. The sound waves bounce back off of dense areas, which will appear whiter or brighter in ultrasound images; they pass through less dense areas, such as tissue or fluid, and these areas will appear darker.
Ultrasonography cannot penetrate bone, but is very good at imaging soft tissue and detecting the presence of fluid, such as blood or urine. It can show the structure of the body's various organs, such as the liver, spleen, and uterus. The ability, through ultrasound, to visualize abnormalities can help detect tumors and other kinds of problems. Ultrasound is extremely valuable in cardiology, where it can be used to monitor the flow of blood in the heart and the contractions of heart muscle,and to assess structural defects.
