Ultrasound is a medical imaging technique that uses an instrument called a transducer that emits high-frequency sound waves, inaudible to human ears, and records the echoes as the sound waves bounce back to determine the size, shape, and consistency of soft tissues and organs. This information is relayed in real time to produce images on a computer screen. Ultrasound sonographers, have special training in how to perform the test. Then a cardiologist or a radiologist will interpret the ultrasound images and the report will be sent to your doctor.