CT colonography

CT Appointments – RVI: 0191 2824330 Freeman Hospital: 0191 2231012

What is CT Colonography?

A CT Colonography is an X-ray examination of the large bowel, which cannot be seen in a normal X-ray of the abdomen. Images are produced using a CT Scanner which uses x-rays to produce two and three dimensional images.

What does the examination involve?

A radiographer or assistant will ask you to undress and put on a hospital gown.

You will be asked to lie on the scanning table and the procedure will be explained. Then you will be asked to turn on your side and a radiographer will insert a small flexible rubber tube into your bottom.

To help relax the muscles of your bowel wall, you may be given a small injection of medicine (Buscopan). You may also receive an injection of a dye (contrast agent) during the test, depending on the reason you are having it.

Carbon dioxide gas is then slowly introduced into your bowel to expand it and make the walls easier to see. When this happens you may briefly feel some discomfort, similar to trapped wind.

You will then have your scans taken whilst lying on your stomach and lying on your back.

When the examination is complete, the tube is removed and you will be shown into a small rest room so that you can use the toilet.

Do I need any special preparation before the examination?

You will receive an appointment letter with preparation information detailing what to do before the examination. It is important that you read these instructions carefully as preparation for this examination may begin several days prior to your appointment.

What are the benefits of having a CT Colonography exam?

This procedure will help us make the correct diagnosis so your doctor will be able to give you the correct treatment. The benefits of an accurate diagnosis far outweigh any potential risk

What are the risks of having a CT Colonography exam?

We are all exposed to natural background radiation every day of our lives. Each x-ray examination gives us a small additional dose. This dose varies with each type of examination. Everything is done within the X-ray department to minimise this dose. X-rays may be harmful to an unborn child, especially in the earlier stages of pregnancy.  We would normally only perform this test in the first ten days of your menstrual cycle (if you are of child bearing age).  Please let us know if this is not the case when you receive your appointment.

There is a small risk that inflating the colon with carbon dioxide gas may cause a perforation. This risk is about 1 in 3000 and lower than that of a colonoscopy.

I am diabetic. Does this change anything?

Please liaise with your Diabetic Nurse regarding the diet and inform the Radiology Appointments Office on the number listed in your letter so that you can be allocated a morning appointment.

I take Metformin (Glucophage, Avandamet) Tablets. Does this change anything?

Yes – Metformin (Glucophage, Avandamet) is most commonly taken by diabetics to control blood sugar, but occasionally is taken for other conditions.

Please let us know on the day of your test if you are diabetic and taking Metformin as we may ask you to stop taking it for two days after the test. [This will only apply to you if you have had an injection of x-ray contrast during the examination.]

How will it feel? Will I have any side effects following the examination?

You may experience temporary pain or discomfort when the carbon dioxide is put into your bowel.

You may also experience a feeling of warmth if you receive the x-ray dye injection.

These are all temporary and will pass.

How long will it take?

The examination should be complete in approximately 30 minutes.

Can I drive home?

There is usually no reason why you should not drive home.

When will I get my results?

A report will be sent to the consultant or GP who requested the procedure, within two weeks of your examination.

I need ambulance/ transport. Do you arrange it?

If you need an ambulance/ transport, you must ask your GP Surgery to arrange it, but you will need to give them three working days notice.  Please note that hospital transport is provided on medical need only.

What if I cannot attend for my appointment?

If your appointment time is not convenient please contact the hospital department that you are attending immediately, so that a more appropriate time can be arranged.  This will enable us to offer the appointment to another patient.