Ultrasound is a test that uses reflected sound waves to produce a picture of organs and other structures inside the body. It does not use X-rays or other types of possibly harmful radiation.
A small handheld instrument called a transducer is passed back and forth over the area of the body being examined. It sends out high-pitched sound waves(above the range of human hearing) that are reflected back to the transducer. A computer analyzes the sound waves and converts them into a picture that is displayed on a video monitor. The picture produced by ultrasound is called a sonogram, echogram, or scan. Pictures or videos of the ultrasound images may be saved as a permanent record.
How It Feels
The gel may feel cold when it is first applied to your stomach unless it is first warmed to body temperature. You will feel light pressure from the transducer as it passes over your abdomen, but you should feel no discomfort. However, if the test is being done to assess damage from a recent injury, the slight pressure of the transducer may be somewhat painful. You will not hear the sound waves.
For ultrasound of the aorta, you may need to avoid eating for 8 to 12 hours before the test.
There are no known risks from having an abdominal ultrasound test.