Download IL421 Computed Tomography (CT) Colonography

Radiology Department
Computed Tomography (CT) Colonography
What is CT Colonography?
CT Colonography is a specialised scan that looks at the large bowel (colon) and the abdomen.
This scan is used as an additional examination to a colonoscopy when the colonoscopy has failed to
identify the entire bowel or as an alternative examination to a colonoscopy if your consultant has
decided that the colonoscopy or its preparation is not suitable for you.
Where will the scan take place and who will perform the scan?
The scan is carried out in the CT department situated in the main X-Ray department. Your scan will
be carried out by a radiographer with a radiology assistant to help with preparations.
What does the scan involve?
When you arrive in the department you will be taken to a cubicle and asked to remove all clothing
from the waist down and you will be provided with a hospital gown to wear, to ensure you are
suitably covered and warm.
At this point you will have a chance to talk through the examination with the radiographer and have
any questions answered before we commence the scan.
Once you are changed and happy to proceed, you will be taken to the preparation area where one of
the radiographers will put a needle, called a cannula, into a vein in your arm or hand. This enables the
staff to inject a muscle relaxant and X-Ray dyes into your veins to help provide the best images for
your scan. If you have an iodine allergy X-RAY dye will not be used.
Once you are ready you will be taken through to the CT scanner for your examination
There are three parts to the scan
1. You will be asked to lie on your back on the CT bed and a muscle relaxant called Buscopan will
be given through your cannula. This medication does not relax you; it relaxes the muscles in
your bowel and should make the CT Colonography more comfortable for you. It can also
make your vision blurred and your heart to beat faster but both of these will wear off over 60
minutes.
2. Next you will be asked to lie on your left hand side as we need to insert a small flexible tube
into your bottom so we can fill your bowel with gas. This gas is harmless and inflates the
bowel to get the best images. Try your best at this point to keep the gas inside by gripping
tightly to the tube in your bottom.
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3. You will then be asked to lie on your tummy and the radiographer will take images of you in
this position, it is important to listen and follow the radiographer’s instructions at this time so
please advise the staff if you have any hearing difficulties. After this you will be asked to roll
over onto your back and X-Ray dye will be given through your cannula. Straight afterwards
another set of images will be taken. Finally we will remove the tube from your bottom and
you will be helped off the bed. You will be able to go to the toilet at this time should you feel
the need.
Are there any side effects or risks with this scan?
The muscle relaxant (Buscopan) that you will be given can cause blurred vision and your heart rate to
increase, both of which will wear off over 60 minutes. Very rarely patients may develop pain or
redness of the eyes, which occurs in the 24hrs after the test. If this happened you would need to go
to hospital immediately for a check-up, but please remember this is very rare.
The CT scan involves x-rays, female patients who are or might be pregnant must inform a member of
staff before the procedure.
You may have x-ray dye injected into your veins called contrast; this can cause a warm feeling as it
passes through your body. If you are allergic to contrast or iodine you need to inform a member of
staff in advance so we can avoid you having this.
Your kidneys get rid of the X-ray dye from your body; there is a risk that if your kidneys do not work
effectively enough that the dye could damage them. To ensure this risk is minimised we check
everybody’s kidney function from a blood test prior to the scan, and we will give advice and take
precautions depending on the results. It is important to keep yourself well hydrated before and after
the scan as this will help your kidneys to get rid of the dye quickly,
There is a small risk (approx 1 in 3000 tests) that your bowel could perforate with this test, if this
happens it usually resolves without treatment, but may require hospital admission and observation
under the care of a surgeon.
Please remember that this test is safe and any serious complications are rare.
Is there any preparation?
There is a special diet that you will need to follow for 2 days before the scan. You will also be given a
bottle of X-Ray-dye called Gastrografin to drink over the 2 days before your scan.
The dye and the diet is to ensure your bowel is prepared correctly for the scan. The dye acts as a
laxative, and also dyes any leftover poo, this is so the poo is easily recognised and not mistaken for
bowel disease. The laxative effect of the dye varies in every patient. We would advise you to remain
near to a toilet for 2 hours after taking the dye.
Full details of the diet and preparation will be given to you at your pre-assessment appointment by
one of the x-ray nurses.
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Can I take my medication?
If you take iron tablets, these need to be stopped 7 days before your procedure. If you take any
other medication, please advise the nurse at your pre-assessment appointment and you will be told if
you need to stop any medications or not.
How long will the examination last?
This scan itself lasts around 20 minutes, but please be prepared to be in the department for up to 1hr
as the preparation before the examination takes time and we will want to keep you for 20 minutes
after the procedure
What happens when the test is finished?
After the examination you may feel mild stomach cramps due to the gas we have inserted into your
bowel, this will wear off as the gas is absorbed back into the bowel.
Your vision is also likely to remain blurred for up to 20 minutes after the scan, and we advise that you
remain in the department and do not drive until your vision is back to normal, which will be at least 1
hour from the time the injection was given.
We will remove the needle from your arm or hand after 20 minutes, then you will be able to get
changed and go home. We advise you to drink plenty of fluids (approx 100ml every hour) over the 20
hours after your scan to help your kidneys flush away the x-ray dye.
You will be able to eat and drink as normal as soon as the scan is finished.
When will I get the results?
The x-ray staff will not be able to give you your results immediately after the scan. This information is
sent to your Consultant and he / she will arrange either a letter to inform you of the scan results or a
follow up clinic appointment.
Contact numbers for advice
If you have any queries or special needs you can contact the X-Ray pre-assessment nurse on 0191 445
3260 (Monday to Friday 9.00am – 5.00pm), or the booking staff on 0191 445 2491 (Monday to Friday
08:00am – 08:00pm).
You can also obtain advice 24hrs a day from NHS Direct on 0845 46 47.
Data Protection
Any personal information is kept confidential. There may be occasions where your information needs
to shared with other care professionals to ensure you receive the best care possible.
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In order to assist us improve the services available your information may be used for clinical audit,
research, teaching and anonymised for National NHS Reviews. Further information is available in the
leaflet Disclosure of Confidential Information IL137, via Gateshead Health NHS Foundation Trust
website or the PALS Service.
Information Leaflet:
Version:
Title:
First Published:
Review Date:
Author:
NoIL421
1
Computed Tomography (CT) Colonography
August 2013
August 2015
Katy-Jo Wilkinson
This leaflet can be made available in other languages and formats
upon request
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