Computed Tomography (CT)

What is a CT scan?

A CT scan is a diagnostic imaging examination that uses x-rays and digital computer technology to produce three dimensional images of the inside of the body.

In CT, we provide cross sectional imaging of a region of the body. This type of imaging allows a more detailed view of the area of interest. Sometimes the use of a contrast medium or ‘dye’ is used to enhance certain structures such as blood vessels and organs. Contrast medium may be injected or taken orally. CT often works in conjunction with other types of imaging to deliver a better clinical image or diagnosis.

CT is used is used for imaging all parts of the body including the chest, abdomen, head and bones. 

Our CT room

The PCH CT room is a colourful environment designed to capture the imagination of children. We provide a non- threatening clinical setting equipped with modern technology to accommodate the shorter attention span of our young patients. The artistic depictions on the walls provide an effective method of distraction, allowing us to deliver a high quality imaging service while optimising patient comfort. The room is also equipped with digital technology that projects images onto the CT scanner and ceiling.

How are the images taken?

The CT scanner is the same type of imaging as an x-ray except that the camera spins around the patient as they move through the scanner. This spinning x-ray tube (which is hidden in the machine) allows us to deliver images of high resolution and detail of the region of interest.

The radiographer will position your child on the CT table after obtaining informed consent from you. We may insert a small cannula into your child’s arm if an intravenous contrast injection is required but this will be fully discussed with you on the day. Any necessary breathing instructions will be explained. The radiographer will then perform the scan, which, just like an x-ray, does not hurt. Your child may be asked to hold their breath depending on the region of the body being scanned, but this will not be for a long time.

If contrast is required, it will be injected during the scan. Once the scan is done, one of the radiologists will check the scan before the patient leaves the department. The images are then reformatted into different planes and sent to the radiologist to look over and write an official report, which is then forwarded to your requesting doctor or team.

What do I do before the test?

If your child’s CT examination requires anaesthesia or any oral and/or intravenous contrasts, they may need to fast for three hours from solids and two hours from all fluids beforehand to prevent nausea. Intravenous contrast is iodine within a liquid that is injected into the blood stream to help highlight blood vessels and demonstrate the passage of blood through the circulatory system.

Oral contrast is designed to delineate the bowel from other internal structures and is either drunk or administered through a nasogastric tube.

Oral contrast is given to most patients having an abdominal CT.

You will be given specific instructions, but commonly patients are asked to drink the contrast about two hours before the examination (the timing will depend on your child’s clinical history).

What you need to do before your child’s examination will be explained to you when you book your appointment. If you are unsure about the instructions you are given or need further information, please do not hesitate to contact the department before your child’s examination.

Will I need to give consent?

Before your child’s CT examination, you will be asked to read and sign a patient information form and provide information about your child’s medical history to help us determine whether they may have an allergy to the contrast and address any concerns you may have. This form also contains information about radiation exposure and intravenous contrast.

Who looks at the images?

A paediatric radiologist will look at the pictures and send a report to your child’s doctor.

What happens after the test?

The radiographer will let you know when your child can leave the department.

After the test your child can eat and drink normally unless your child’s referring doctor has told you otherwise.

If your child has had intravenous contrast they will be asked to stay in the department for 15 minutes after the examination.

When do I get the results?

The radiologist will review the images and send a report to the doctor who referred your child to the department. If there is a serious problem that requires treatment, the doctor will be notified before you leave.

If you were referred by a PCH doctor, the results will be available at your child’s next outpatient clinic appointment at PCH. If your GP referred you, the results will be sent to them.

In some cases, the requesting doctor will ask you to return immediately after the scan to see them. They will contact the radiologist about your child’s results.

How should I prepare my child?


  • Bring along a special toy or dummy
  • Talk to your child during the test
  • If your child is very young, we may ask you to feed them just before their scan to settle them and encourage them to sleep. This may reduce the need to give your child an anaesthetic.

Toddlers and preschool aged children

  • Explain the test to your child just before their appointment as they may become anxious if they are told about it too far in advance.
  • On the day of the test, let your child know they will be having some pictures taken and tell them that you will stay with them during the test.
  • Bring their favourite toy or book and a snack for after their test.

School aged children 

  • Explain to your child in simple language that they are going to hospital to have some pictures taken of their body and that you will stay with them during the test.
  • If your child needs to fast before their procedure, bring along a snack for after the test.