An ultrasound scan is a medical test that uses high-frequency sound waves to capture live images from the inside of your body. It’s also known as sonography. The technology is similar to that used by sonar and radar, which help the military detect planes and ships. An ultrasound allows your doctor to see problems with organs, vessels, and tissues without needing to make an incision.With the help of sonography it is easy and absolutely painless to examine the structure of many organs and regions of the body. Unlike other imaging techniques, ultrasound uses no radiation. For this reason, it’s the preferred method for viewing a developing fetus during pregnancy.