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Ultrasound Scan

What is an ultrasound scan?

Baby having a head ultrasound 

An ultrasound uses sound waves to take pictures of the inside of your child's body. These pictures give your child's doctor information about the size, shape, and texture of the body part being scanned.

A sonographer and a radiologist will be involved in your child's scan and in caring for your child during the test. A sonographer is an expert in the use of ultrasound machines. A radiologist is a doctor who specializes in tests that give pictures of the inside of the body, such as ultrasound. The sonographer and the radiologist will give a report of the scan to your child's doctor.

Many doctors' offices have ultrasounds. Depending on your child's condition, the test may be done in a hospital.

An ultrasound scan usually takes about 45 minutes, but it can take a little longer.

Preparing for an ultrasound scan

Depending on the body part being scanned, your child may need to drink some water or clear fluids before the test. However, sometimes an empty stomach makes the test results easier to read. If this is the case, your child may be asked to not eat or drink anything for a few hours before the exam.

If your child has diabetes or another metabolic problem, he does not need to fast before the scan. If you are not sure how to prepare for your child's test, ask your doctor or the technologist who will be performing the ultrasound.

Here are some general guidelines:

Abdominal ultrasound

If your child is having an ultrasound of the abdominal (belly) area, he should fast before the scan. This means he should not eat or drink anything except water or apple juice. How long your child should fast depends on the age of your child.

Age (years)

Fasting period

0 to 2

2 hours

3 to 4

3 hours

Over 4

4 hours

Pelvic ultrasound

For examinations that involve the pelvic organs, such as the bladder, uterus, and ovaries, we ask that patients try to have a moderately full bladder. An hour to 90 minutes before the time of your appointment, your child should try to drink 2 to 3 glasses of water or apple juice.

Getting your child ready for the test

Sometimes, children get nervous about new experiences. Take the time to read this information carefully. Explain it to your child using words he will understand. Children who know what to expect are usually less nervous. The ultrasound scan is easier and faster when your child cooperates. Explain that you will stay with your child the whole time.

There is nothing dangerous about an ultrasound scan. It does not hurt.

During an ultrasound

After your child has checked in, the sonographer will take him to the scanning room. The scanning room has a bed, an ultrasound machine, and a screen that shows the pictures from the ultrasound. The lights in the room will be turned down so the sonographer can see the screen easily.

Your child will need to loosen or take off his clothes around the area to be scanned, or your child may need to change into a hospital gown before the scan begins. Then your child will lie down on the bed.

The sonographer will use a small hand-held camera called a probe to take pictures of the body. The sonographer will put warm gel on the probe. The gel feels like warm soft cream and does not hurt. The probe is gently placed on your child's skin over the area to be scanned.

As the probe moves over your child's body, a moving picture will appear on the ultrasound screen. The sonographer may ask your child to hold his breath while a still picture is taken. Many pictures will be taken during the test.

After the sonographer has taken the pictures, he or she will show them to the radiologist. You may be asked to stay in the scanning room while the radiologist is reviewing the pictures. Sometimes the radiologist will come in to meet you, or more pictures may be needed. After the radiologist has looked at all the pictures, the sonographer will let you go.

There are no side effects or after-effects from an ultrasound test.

Your child's doctor will talk to you about the test results

The radiologist will look at your child's ultrasound pictures. He or she will also look at other tests that your child may have had. A report will then be sent to your doctor. Your child's doctor will talk to you about these results at your next appointment.

Key points

  • An ultrasound machine uses sound waves to take pictures of the inside of the body.
  • Let your child know what will happen during the test. Tell your child you will be with him the whole time.
  • Ask the staff at the ultrasound clinic if your child should not eat or drink before the test.
  • Ultrasounds do not hurt. They have no side effects.

Luc Trottier, RDMS


At SickKids:

Outpatients must first register at the Diagnostic Imaging Registration Desk on the second floor in the Elm Wing. After you register, the receptionist will direct you to the ultrasound department on the second floor of the Black Wing.

Inpatients who need an ultrasound will be taken from their room to the ultrasound area by a transportation aide.

If you need to cancel your child's ultrasound test, please call (416) 813-6082. We will give the appointment time to another patient. Many people are waiting for an ultrasound appointment. If you are late, your child's appointment may be delayed or rescheduled.