Your child is having a CT scan

This page explains about your child is having a CT scan and what to expect when your child comes to Great Ormond Street Hospital (GOSH) to have this procedure.

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.

Why does my child need a CT scan?

What does the scan involve?

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 you could be pregnant, please let us know before the scan.

If the scan is of your daughter’s tummy area and she is over 12 years of age, then the scan should be done within the first ten days of her period. It is a legal requirement that we ask if there is any chance that your daughter could be pregnant. Please note that a male radiographer may do this. We apologise for any embarrassment this may cause.

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.

Your child will need to lie very still for the scan, so we may suggest that he or she has some sedation to help. This may involve an injection but we will apply some local anaesthetic cream to the area half an hour beforehand to numb the area.

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 before the scan?

You will receive specific instructions in your appointment letter. If your child is having sedation, you should follow the instructions below. If you do not follow these instructions, your child’s scan may be cancelled. Your admission letter will tell you which ward to report to first. If your child is having the scan without sedation, please report to the reception desk in the x-ray department.

We will then call you when your child is due for his or her scan. 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.

What happens afterwards?

Before the scan

Sleeping

• The evening before the scan, reduce the amount of sleep your child has by allowing him or her to go to bed two hours later than usual.
• On the day of the scan, wake your child at least one hour earlier than usual.
• Try to keep your child awake on the way to the hospital.

Fasting

• All children who are having sedation should finish any food or milk drinks at least four hours before the sedation is given.
• He or she can drink clear fluids (water-based drinks, like weak squash) up to two hours before the sedation is given.
• Your child should not have anything to eat or drink in the two hours before the sedation is given.
• If you do not follow these instructions, your child’s scan will be cancelled.

After the scan

• The nurses will check that your child has recovered well before you can go home.

• He or she may feel sick and vomit in the 24 hours after the sedation. If this is the case, do not give your child anything else to eat until he or she can keep a drink down. As long as your child is drinking, it does not matter whether he or she does not feel like eating for a couple of days. You should encourage, but not force, your child to drink.
• He or she may be tired and a little clumsy for 24 hours after the sedation, so do not allow any activity such a riding a bicycle that may lead to a fall.
• Do not worry if your child is sleepier than usual over the 24 hours following the sedation. This is due to the medicine, which remains in the system for a little while following the sedation.
• Keep a close eye on your child until he or she is back to normal. Do not leave him or her unattended or with an inexperienced carer.
• Your child may have mood changes, which make him or her irritable. This is only temporary.
• If your child is sleepy or difficult to rouse, make sure he or she is in a safe position on their side and ring your GP immediately.

Last reviewed by Great Ormond Street Hospital: June 2011
Ref: 2011F0569 © GOSH Trust June 2011
Compiled by the Radiology department in collaboration with the Child and Family Information Group.

This information does not constitute health or medical advice and will not necessarily reflect treatment at other hospitals. If you have any questions, please ask your doctor. No liability can be taken as a result of using this information.