Ultrasound is an imaging method that is most often used in medicine to visualize the internal structure of the body. A small, handheld device called a transducer is held to the area being studied, sending high-frequency sound waves and collecting the ones that bounce back.
These waves are then used by a computer to construct a visualization of the body’s interior. Ultrasound is a useful diagnostic tool that can be used to monitor a developing fetus during pregnancy, guide needles for a biopsy, or examine body lumps and heart vessels invisible to the naked eye.