Centres/Radiology/CT scan/CT colonography

CT colonography (virtual colonoscopy)

CT colonography in Tunis, Tunisia · Centre Urbain Nord

CT colonography in Tunis: virtual colonoscopy by CT scan to examine the colon when colonoscopy is incomplete or not advisable.

Request a quote +216 36 402 036

What is it?

CT colonography, or virtual colonoscopy, is a CT scan of the abdomen that shows the inside of the colon (large bowel) in 3D images, without passing an endoscope along the whole length of the bowel. It is mainly offered when a colonoscopy could not be completed, or when it is not advisable (for example because of age, health problems or anticoagulant treatment), according to the doctor's opinion. As with a colonoscopy, the colon must be well emptied beforehand (diet and laxative). CT colonography can detect polyps or a tumour, but cannot remove them or take a biopsy: if an abnormality is found, a standard colonoscopy is then needed.

When is it indicated?

Incomplete colonoscopy

When the endoscope could not examine the whole colon, it shows the remaining part.

Colonoscopy not advisable

Depending on the doctor's opinion, it is an alternative when colonoscopy carries a particular risk.

Looking for polyps or a bowel tumour

It detects lesions, which are then removed or biopsied during a colonoscopy.

Preparation

1Tell us if you are pregnant or think you might be: a CT scan uses X-rays

2Follow exactly the preparation given when you book: a low-fibre diet for a few days, then a laxative the day before

3A tagging drink may be included in the preparation, to make any remaining residue visible

4If an injection is planned, tell us about any allergy (especially to an iodinated contrast agent), kidney disease, diabetes or myeloma; a recent blood test (creatinine) may be requested

5Tell us if you take metformin (a diabetes treatment): whether to pause it around the injection is decided by the doctor

6Bring your referral, previous imaging (CT scan, MRI, X-rays, ultrasound) and any relevant reports

Procedure

You remove clothing and metal objects from the area to be examined; a gown may be provided

You lie on your side; a small soft tube is placed in the anus

Gas is gently blown in to open out the colon: this causes a temporary bloated feeling

A medicine that relaxes the bowel may be injected, according to medical advice

Two passes are done, on your back and then on your front (or side), holding your breath for a few seconds

If an injection is needed, the iodinated contrast agent is given through a small drip in your arm: a brief feeling of warmth and a metallic taste are normal

The tube is removed; the bloating passes quickly and you can resume your activities

Duration

About 15 to 30 minutes in total

Results

The images are analysed by a radiologist, who writes a report. The report is given to you with the images and sent to your doctor, who will explain the results and the next steps. You will be told when to expect it on the day of the examination.

Precautions and contraindications

A CT scan uses X-rays: the dose is set as low as possible while still giving useful images, and the examination is only done when it is justified

Pregnancy: a relative contraindication; a CT scan is only performed if it is essential, after medical advice

Temporary discomfort and bloating caused by the gas

Bowel perforation: exceptional

Allergic reaction to the iodinated contrast agent (if injected): rare and usually mild (redness, itching); serious reactions are exceptional and the team is trained to manage them

It cannot remove a polyp: a colonoscopy is needed if an abnormality is found

Your doctor and the radiology team will inform you in detail before the examination. Feel free to ask them your questions.

This information is general and does not replace the advice of your doctor, who chooses the examination suited to your situation.