Ultrasounds 101: What Every Patient Needs To Know

How Does It Work?

Ultrasounds work to produce images through sound waves. The machine sends sound waves through the body, and whenever the waves encounter something, a tiny portion of them bounce back. When an object is dense, such as a stone in a gallbladder, a higher amount of sound waves will bounce back. This bouncing back or echoing is the key to understanding how ultrasounds work. A machine interprets the sound echoes to get a picture of the various densities of the objects that the ultrasound waves encounter. The machine that turns the sound echoes into an image depicts all of these separate densities as shades of gray. Machines have the option of transmitting sound waves at various speeds. A higher speed or frequency of ultrasound wave provides better resolution, but it cannot penetrate as deep into the body.

Continue to learn about the different types of ultrasounds.