What is a CT scan?

What is a CT scan?

CT stands for ‘computed tomography’. A CT scan is a uses X-rays to take pictures inside the body to help diagnose symptoms. It shows your bones and internal organs. The CT scanner is shaped like a large donut, with a table that moves you through a hole in the middle.

The scans taken by members of staff called radiographers.

How do we prepare for the scan?

Please bring your child’s appointment letter with you on the day of their scan. The radiology reception staff will check their details and book them in. We will do our best to keep to your appointment time.

Sometimes we have to do emergency scans at short notice which may cause slight delays. If this happens, we will inform you and keep you updated.

Does my child need contrast media?

The CT scanner is very good at providing information on bones, but some CT exams will need contrast media to see the internal organs better. If your child needs contrast media for their scan, we may ask you to bring them in before their scan appointment so we can apply an anaesthetic cream to numb the area where a cannula will go in. The appointment letter will tell you if this is necessary.

What should my child wear?

Your child may need to remove some clothes if the radiographer thinks they will show up on the scan. The radiographer will let you know if this is the case and provide your child with a hospital gown and a cubicle to change in.

We advise patients not to wear any clothes with zips, poppers, or buttons made of metal.

Any other metallic objects around the area being scanned, such as jewellery, piercings, glasses and hearing aids may need to be removed before the scan can start.

What if my child has periods?

For certain CT exams, if you child is 12 or older and has periods, the scan must be done within 10 days of the start of their last period.

If this is needed for the scan, the appointment letter will ask you to contact the X-ray appointments team to arrange the scan for an appropriate date.

If this is necessary, the radiographer will ask your child before the scan if they have started their periods, and when the first date of their last period was.

If their last period was over 10 days ago, we may need to reschedule the scan.

What happens during the scan?

The radiographer will weigh your child and explain the procedure before they begin.

Your child will be asked to lay on a padded table and stay very still during the scan. They will have some cushioned Velcro straps placed over them as the table will raise up into the air slightly.

During the scan, the table will move your child through the hole in the middle of the machine and back out a few times. As this happens, an X-ray camera inside the donut-shaped machine will spin around the central hole while it takes X-ray images from every different angle.

Is the machine scary?

The machine makes a noise a little bit like a washing machine but nothing will touch your child and the procedure is painless. The scanner is open ended on both sides so it should not be too uncomfortable for claustrophobic patients. The scan usually only takes a few minutes.

Can I stay in the room?

During the scan, 2 parents or carers can stay in the scan room with your child.

You will have to wear a protective lead apron if you stay in the room for the scan. You will also have to sign to say that you are happy to stay in the room during the scan, and that you are not pregnant.

We advise that pregnant people do not stay in the scan room during the scan due to the potential risk it can have to an unborn baby.

Other than your child, no one under the age of 18 should stay in the room during the scan. If you have brought other children to the appointment with you, they will have to remain in the waiting area until the scan is finished.

Does my child need to do anything during the scan?

Some scans have specific instructions to follow.

For example, your child may be asked to breathe in and hold their breath so that we can see what their lungs look like when they are full. They may also be asked to breathe out and hold their breath so we can see what their lungs look like when they are empty. If breathing instructions are necessary, the machine will play a sound clip that will let your child know when to breathe in, out, and hold their breath. As well as the audio instructions, the scanner also has light-up cues for the hard of hearing.

If the scan has any specific instructions the radiographer will go through them with your child before the start of the procedure. Other than these instructions, your child will have to stay still.

What if my child cannot stay still?

It is extremely important that they stay as still as possible during the scan. You may find it helpful to distract them to help keep them still. You are welcome to play videos on your phone or get their attention with toys. We can offer stickers and certificates to encourage patients to stay still.

For small children or children who are struggling to stay still, it may be better to scan them while they are asleep. For our youngest children, we recommend that you wait until your child is on the scan table before giving them a feed. We can turn the lights down to help them fall asleep. Please bring any blankets or toys that you think will help your child relax.

For children who are a little older, it is sometimes necessary to give your child some sedation to help them sleep. Please see our resource about sedation for CT scans here.

In some situations, the doctor who has asked for the examination might decide that your child will need a general anaesthetic before the scan. Please visit our general anaesthetics resource for more information.

If the doctors decide that your child would benefit from having either sedation or a general anaesthetic, they should discuss this with you and get your consent for the procedure.

When will we get the results?

Once the scan is complete, the images will be reviewed by a specialist X-ray doctor called a radiologist who will pass the results of the test on to the doctor who requested the scan. The doctor who requested the scan will be able to discuss the results with you at your next appointment.

If you are scheduled to have an appointment with the doctor that requested the scan straight after the examination is complete, they will have access to the images and may be able to discuss the results with you immediately.

Is the scan safe?

The CT scanner creates images using X-rays which are a form of radiation.

Although this radiation does pose a theoretical risk, every step is made to make sure that the amount of radiation used is as low as possible. For most CT scans, the amount of radiation that your child is exposed to will be the same as the amount of naturally occurring radiation they will be exposed to over the course of several months of everyday life.

The doctor who has requested the scan will have followed national guidelines that recommend that the scan go ahead. Every request for a CT scan is also reviewed by a senior radiologist who will check that it is reasonable for the scan to go ahead.

Please be assured that the radiographers and radiologists looking after your child will always use equipment and techniques that maximise the diagnostic information gained whilst minimising the amount of radiation used.