Have you ever seen a picture of a baby inside his or her mother's body? If so, you may have wondered how doctors get their cameras inside the body to take these pictures.
Would you believe those pictures don't come from cameras? They're actually made with sound!
Ultrasound — also called ultrasonography — is a medical technology that uses high-frequency sound waves and their echoes to create images of what the inside of the body looks like. The scientific principles that make this possible are similar to those that allow bats, whales, and dolphins to “see" what's around them using echolocation.
Ultrasound technology was actually first developed during World War I to help track submarines underwater. The technology was called SONAR, which stands for SOund Navigation And Ranging. Ultrasound wasn't used for medical purposes until the 1950s.
The high-frequency sound waves used in ultrasound technology cannot be heard by human ears. Instead, a special tool called a transducer is used to send sound waves and detect the echoes that return.
As the sound waves pass through the inside of the body, different types of tissues conduct sound differently. A variety of echoes are produced.
These echoes can identify the size and shape of organs and other objects inside the body. A special computer in the ultrasound machine can read these echoes to produce a picture of what the inside of the body looks like.
Usually, doctors use an ultrasound to study a particular part of the inside of the body, such as an internal organ…or a pregnant woman's unborn baby! Ultrasound technology is very safe, and doctors like it because it is noninvasive. That means it does not involve penetrating the skin or body.
Ultrasounds are used often during pregnancy to help doctors keep an eye on a baby's development. There are also many other medical uses for ultrasound technology. Ultrasounds have been used to explore most parts of the body to diagnose various issues with internal organs.
Recent advances in technology have resulted in the development of 3D ultrasound imaging. By using multiple two-dimensional images, special computers are able to combine multiple images into a 3D rendering. Doctors believe this new technology will lead to earlier detection of cancer, as well as the ability to better assess blood flow in organs and development of babies in the mother's womb.