What It Is

An abdominal ultrasound is a safe and painless test that uses sound waves to make images of the abdomen (belly).

During the examination, an ultrasound machine sends sound waves into the abdominal area and images are recorded on a computer. The black-and-white images show the internal structures of the abdomen, such as the appendix, intestines, liver, gall bladder, pancreas, spleen, kidneys, and urinary bladder.

A complete ultrasound of the abdomen evaluates all of the abdominal organs. A limited ultrasound of the abdomen evaluates one or multiple organs, but not all.

Why It's Done

Doctors order an abdominal ultrasound when they're concerned about symptoms such as abdominal pain, repeated vomiting, abnormal liver or kidney function tests, or a swollen belly. Abdominal ultrasound tests can show the size of the abdominal organs and can help evaluate injuries to or diseases of the abdominal organs.

Specific conditions that ultrasound can help diagnose include:

• appendicitis (inflammation of the appendix)
• pyloric stenosis (narrowing of the lower part of the stomach, which blocks the passage of food from the stomach to the intestines)
• stones in the kidneys or gall bladder
• abdominal masses such as tumors, cysts, or abscesses
• abnormal fluid in the abdomen

Abdominal ultrasounds can be used to guide procedures such as needle biopsies or catheter insertion (to help ensure accurate placement of the needle or the catheter). Abdominal ultrasounds also are used to monitor the growth and development of a baby in the uterus during pregnancy.

Preparation

In routine cases, children often require some prepping before an abdominal ultrasound, and your doctor may ask that your child not eat or drink anything for several hours before the test. In an emergency situation, however, an abdominal ultrasound may be performed without any preparation. You should tell the technician about any medications your child is taking before the test begins.

Procedure

The abdominal ultrasound usually will be done in the radiology department of a hospital or in a radiology center. Parents usually can accompany their child to provide reassurance and support.

Your child will be asked to change into a cloth gown and lie on a table. The room is usually dark so the images can be seen clearly on the computer screen. A technician (sonographer) trained in ultrasound imaging will spread a clear, warm gel on the skin of the abdomen. This gel helps with the transmission of the sound waves.

The technician will then move a small wand (transducer) over the gel. The transducer emits high-frequency sound waves and a computer measures how the sound waves bounce back from the body. The computer changes those sound waves into images to be analyzed. Sometimes a doctor will come in at the end of the test to meet your child and take a few more pictures. The procedure usually takes less than 30 minutes.

What to Expect

The abdominal ultrasound is painless. Your child may feel a slight pressure on the belly as the transducer is moved over the body, and the gel may feel wet or cold. You'll need to tell your child to lie still during the procedure so the sound waves can reach the area effectively. The technician may ask your child to lie in different positions or hold his or her breath briefly.

Babies might cry in the ultrasound room, especially if they're restrained, but this won't interfere with the procedure.

Getting the Results

A radiologist (a doctor who's specially trained in reading and interpreting X-ray and ultrasound images) will interpret the ultrasound results and then give the information to your doctor, who will review the results with you. If the test results appear abnormal, your doctor may order further tests.

In an emergency, the results of an ultrasound can be available quickly. Otherwise, they're usually ready in 1-2 days. In most cases, results can't be given directly to the patient or family at the time of the test.

Risks

No risks are associated with an abdominal ultrasound. Unlike X-rays, radiation isn't involved with this test.

Helping Your Child

Some younger children may be afraid of the machinery used for the ultrasound. Explaining in simple terms how the abdominal ultrasound will be conducted and why it's being done can help ease any fears.

You can tell your child that the equipment takes pictures of the belly, and encourage him or her to ask the technician questions. Tell your child to try to relax during the procedure, as tense muscles can make it more difficult to get accurate results.

If You Have Questions

If you have questions about the abdominal ultrasound, speak with your doctor. You can also talk to the technician before the exam.

Reviewed by: Yamini Durani, MD
Date reviewed: February 2013