Your child is having a CT scan

This page explains about having a CT scan at Great Ormond Street Hospital (GOSH), how to prepare for it and what care your child will need afterwards.

What is a CT scan?

A CT scan (Computed Tomography) uses x-rays and computers to take pictures of the internal structures of your child’s body. The CT scanner is a large doughnut-shaped machine with a hole in the centre through which a special bed can move.
The scan can last anywhere from five minutes to 20 minutes, depending on the area and complexity of the scan. Although the bed will move through the scanner, it will not come into contact with your child.
If your child is anxious about the scan, you should discuss exactly what might happen in an open and honest manner. If you would like some advice about preparing your child for his or her scan, please ring the department’s play specialist.

Are there any alternatives?

Your child may need this scan to show the doctors detailed pictures of part of his or her body. Various types of scan such as ultrasound and x-rays can show the size and shape of parts of your child’s body but not in as much detail as a CT scan. The information from the scan is then used to help with diagnosis and plan their treatment.

When you receive your appointment letter

If you are unable to keep this appointment, please inform the department as soon as possible beforehand. Sometimes, we can offer the appointment to another child on the waiting list.

The day of the scan

When you arrive at the hospital, you should report to the MRI/CT department. Some scans need additional preparation – information about whether your child needs any additional preparation is in your appointment letter.

Children having the scan without sedation or general anaesthetic do not need to ‘fast’ or stop eating and drinking before the scan unless stated in the appointment letter.

You are welcome to stay with your child during the scan, but you will need to wear a lead apron to protect you from the x-rays. If you are pregnant or think you could be pregnant, you should let us know beforehand. If your daughter is 12 years old or older, we will ask her about her periods and any possibility she could be pregnant.

It can also help if your child has a favourite toy to hold as well.

What does the scan involve?

Your child will need to lie on a special bed, either head first or feet first depending on the part of his or her body being scanned. When your child is in the correct position, the radiographer will go into the control room to operate the scanner. This will involve moving the bed up and sliding it through the middle of the scanner.

The scanner will make some quiet noises while the pictures are being taken. The radiographer will be able to talk to you and your child throughout the scan using the in-built microphone. Doctors called radiologists, who are trained to interpret CT scans, may come and check the pictures before the scan is finished. When the test has finished, the radiographer will move the bed away from the scanner so that your child can get up and leave.

Are there any risks?

CT scans are only ever performed if the benefits outweigh the risks involved. CT does use radiation, but the dose is kept as low as possible. This is because the radiographers are specially trained to obtain the best quality pictures while using the lowest amount of radiation possible.

Some scans may need a small injection of radiographic contrast (dye) to help show up an area more easily. Once again local anaesthetic cream will be applied if your child wants.

What happens afterwards?

If your child did not have sedation for the scan, you will be able to go home straight after the scan has finished. The radiologist will send a report of the scan to your child’s doctor in time for your next appointment. If you have not been given a follow up appointment to see your consultant, please contact their secretary after two weeks.

Compiled by: 
The Radiology department in collaboration with the Child and Family Information Group.
Last review date: 
October 2016


Please note this is a generic GOSH information sheet. If you have specific questions about how this relates to your child, please ask your doctor. Please note this information may not necessarily reflect treatment at other hospitals.