Ultrasound imaging is usually a painless medical test that helps physicians diagnose and treat medical conditions. Ultrasound or sonography is a technique that uses sound waves to study and treat different areas of the body. It uses high-frequency sound waves that are transmitted to the area of interest and returns echoes that are recorded and captured as images. Ultrasound is non-invasive and does not involve radiation. Because ultrasound images are captured in real-time, they can show the structure and movement of the body's internal organs, as well as blood flowing through blood vessels.