An echo scan is a type of diagnostic imaging test that uses sound waves to create images of the inside of your body. The test is also called ultrasonography or sonography. During an echo scan, a handheld device called a transducer is passed over your skin. The transducer emits sound waves that bounce off organs and tissues inside your body and return to the transducer. The transducer collects these echoes and sends them to a computer, which creates images from the data. Echo scans are used to assess the health of organs such as the heart, liver, kidneys, and pancreas, as well as to evaluate blood flow and detect any abnormalities.