For CT colonography, a CT scanner is used to create images of the colon. A CT (computerised tomography) is a piece of equipment that uses X-rays to create images from the inside of your body. It takes multiple “slices’ that we can scroll through / see your body in 3D.
The CT scanner is shaped like a large, open ring. This examination takes place at the Radiology Department.
Preparation
In order for the examination to be successful, you need to follow a low-fibre diet and drink the contrast agent Telebrix (50 ml) the day before the examination. This diet ensures that the contrast agent spreads effectively through the digestive tract content. It is also important that you drink a lot; 10 to 12 glasses of fluids.
The day before the examination
Follow a low-fibre diet:
- Have 1 glass of Telebrix with lunch: low-fibre diet
- Have 1 glass of Telebrix with diner: low-fibre diet
You can drink this contrast agent from a glass. It does not need to be diluted, but can be drunk with syrup if necessary. When taking this contrast agent, diarrhoea is almost always a result. An advantage of this is that the colon is more easily visible during the examination. In the event of diarrhoea, you must take account of a decreased effect of medication, such as the contraceptive pill.
Low-fibre diet
- Cereal products:
- white bread, rusk, toast
- white rice, pasta
- pancakes
- Fruit and vegetables:
- potatoes
- well-cooked vegetables, such as carrots, cauliflower, chicory, endive, spinach
- fruit, only if ripe, peeled and de-seeded
- All types of meat, fish, chicken
- Soup: only broth
- Sandwich fillings:
- cheese, meats, egg, sugar
- sweet fillings, except for peanut butter, jam with fruit pieces, marmalade
- Drinks:
- syrup, soft drink, tea, coffee, mineral water, milk and milk products (no fruit yoghurt or quark), fruit juice without pulp, alcoholic drinks
- Snacks:
- sweets, ice cream and chocolate without nuts, cake (no biscuits)
- Spices:
- salt, pepper, paprika powder, nutmeg, cinnamon, mustard, ketchup, green herb mix, parsley
High-fibre diet and therefore not permitted before the examination
- Wholegrain cereal products:
- brown, wholewheat and rye bread
- wheat and corn bran, muesli, crunchy muesli
- wholegrain and multigrain pasta
- brown rice
- porridge
- Fibrous vegetables:
- asparagus, celery, cabbage, string beans, green beans, leeks, peas, bean sprouts, sweetcorn, mushrooms, tomatoes, raw vegetables
- Certain types of fruit:
- oranges, grapefruit, mandarins, pineapple, mango, kiwi
- dried fruit such as dates, figs, prunes, currants, raisins, coconut
- unripe fruit
- Nuts, peanuts and seeds:
- all types of nuts and peanuts
- sesame and poppy seeds, sunflower seeds
- Other:
- hot spices, popcorn
The day of the examination
You can have a liquid breakfast, such as custard, yoghurt or quark without fruit. You drink another bottle of Telebrix 1.5 hours before the examination. Try to go to the toilet a few times to defecate.
The examination
You cannot keep your clothes on during the examination and will be given a hospital gown. You will be requested to lie down on an X-ray table. You will first be given an injection with an agent to relax the intestine. Next, you will turn onto your right side and a tube will be inserted into your anus. After it is inserted, a small balloon in the tube will be inflated to ensure that it stays in place. Via the tube, carbon dioxide will be pumped into the colon.
A CT scan will be made out while you lie on your back. Then another scan will be performed while you lie on your stomach. In order to prevent movement during the scan, you will be asked to inhale and hold your breath.
After the CT scan, the radiographer will remove the tube. You can use the toilet if you need to.
Duration
The examination takes approximately 20 to 30 minutes.
Important information
If you are pregnant or think you might be, please report this to your doctor or the radiographer before the examination.
You have been given an injection to relax your intestine. There is a minor chance that your vision will be temporarily blurry due to this injection. We recommend that you refrain from driving a vehicle after the examination or that you wait half an hour until your sight has recovered.
The results
Your doctor who requested the examination, will inform you of the results.