What is an ultrasound?

Ultrasound, also known as sonography or ultrasonography, is a procedure that transmits high-frequency sound waves, inaudible to the human ear (can’t be heard), through body tissues. The echoes are recorded and transformed into video or photos of the internal structures of the body in order to help make a diagnosis.

Ultrasound images help in the diagnosis of a wide range of diseases and conditions. The idea for ultrasonography came from sonar technology, which makes use of sound waves to detect underwater objects.

Ultrasound is used to create images of soft tissue structures, such as the gall bladder, liver, heart, kidney, female reproductive organs—and even of fetuses still in the womb. Ultrasound can also detect blockages in the blood vessels.

Ultrasound might be used with other diagnostic procedures or by itself.

Are there any side effects with ultrasound?

Ultrasound is not hazardous. There are no harmful side effects. In addition, ultrasound does not use radiation, as x-ray tests do.

On the day of the test

Please report to the ultrasound department on the day of the test. The child is encouraged to eat as he or she normally would. It is important that your child arrives for the exam with a full bladder. If your child does not have a full bladder, the test might be delayed, along with appointments following the exam.

Fluid requirements

Be sure to follow these fluid requirements before the test:

  • Ages newborn to toilet-trained —Encourage fluids one-half hour before the exam.
  • Ages toilet-trained to 4 years — Have your child drink 8-10 ounces of fluid one-half hour before the exam.
  • Ages 5-8 years — Have your child drink 16 ounces of fluid one-half hour before the exam.
  • Ages 9-12 years — Have your child drink 24 ounces of fluid one-half hour before the exam.
  • Ages 13-18 years — Have your child drink 21 ounces of fluid one hour before the exam.

Once the child drinks, he or she should NOT empty his or her bladder. It is expected that infants and small children will not have the bladder control that older children do. If your child is unable to drink fluids for any reason, please consult your physician. Children do not have to fast for this test.

During the test

The ultrasound test usually takes 30-60 minutes to complete.

  • Your child will be asked to lie on a comfortable table, either on his or her side, back, and/or stomach.
  • A small amount of water-soluble gel is applied to the skin over the area to be examined. The gel does not harm the skin or stain clothes.
  • A hand-held instrument, called a transducer, is placed against the gel on the body. The transducer is moved back and forth across the area being examined.
  • The technologist will instruct your child when, if necessary, to hold his or her breath to prevent motion on the images.
  • The technologist does not interpret the images, but rather, takes the images for the radiologist to review for diagnosis. A radiologist might also review the images on the screen during the examination with the technologist.
  • After the procedure is complete, the technologist will wipe off any remaining gel used during the procedure.
  • The ultrasound test usually takes from 30-60 minutes to complete.
After the test

The radiologist will review the images. A written report of the radiologist's findings will be forwarded to your child's referring physician via the electronic medical record. If your child’s physician is outside the Cleveland Clinic, the physician will receive results by fax or mail.

Please allow a few days before contacting your child's physician for the results. The physician will then discuss the test results with you.


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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 2/15/2017...#9033