Ultrasonography

[GarryDrold]

Ultrasonography uses high-frequency sound (ultrasound) waves to produce images of internal organs and other tissues. A device called a transducer converts electrical current into sound waves, which are sent into the body’s tissues. Sound waves bounce off structures in the body and are reflected back to the transducer, which converts the waves into electrical signals. A computer converts the pattern of electrical signals into an image, which is displayed on a monitor and recorded as a digital computer image. No x-rays are used, so there is no radiation exposure during an ultrasonography.
Ultrasonography is painless, relatively inexpensive, and considered very safe, even during pregnancy. (See also Overview of Imaging Tests and Medical Care During Pregnancy: Ultrasonography.)

[Mary Mallozziberg]

A technique using echoes of ultrasound pulses to delineate objects or areas of different density in the body.

[Greta]

In ultrasonography, a signal generator is combined with a transducer. Piezoelectric crystals in the signal generator convert electricity into high-frequency sound waves, which are sent into tissues. The tissues scatter, reflect, and absorb the sound waves to various degrees. The sound waves that are reflected back (echoes) are converted into electric signals. A computer analyzes the signals and displays an anatomic image on a screen.
Ultrasonography is portable, widely available, relatively inexpensive, and safe. No radiation is used.