Ultrasound imaging is a common diagnostic procedure which uses high-frequency sound waves to produce dynamic images (sonograms) of organs, tissues or blood flow within the body. Ultrasonography is a technical term for ultrasound imaging. It can be used to perform both diagnostic and therapeutic procedures such as when ultrasound is used as a guide in interventional procedures. During ultrasound imaging, a hand-held probe (called a transducer) is placed directly on the region to be visualized and moved over it. A water-based gel is applied to the area to couple the ultrasound between the transducer and you.
The sound waves bounce off structures within the organ travelling at different speeds through different tissues. This information is processed by a computer to form images, which may be viewed on a monitor.
Ultrasounds are harmless and the procedure is usually not associated with any risks.