What happens during the test?
This test is painless. You will be asked to lie very still on a table. The table will pass through a doughnut-shaped machine. This machine will rotate around the table to take many X-ray images at different angles. The test will take 5 to 20 minutes depending on the part of the body being examined.
Sometimes, a dye containing iodine is injected into the blood during a CT scan. The dye can also be taken by mouth or through a rectal tube. The dye helps make blood vessels and certain organs in the body more visible for the CT pictures.
How should I prepare for this test?
Your doctor may tell you not to eat or drink fluids four hours before the test. For some CT scans, you may be required to take a laxative or use an enema. You may be asked to arrive early for your scheduled appointment to be given a dye to improve the clarity of the X-ray images. The dye may be given by intravenous injection or by mouth.
You might feel cold lying on the CT table. Other people feel anxious or claustrophobic inside the scanner. If this happens, you might be given a sedative to help you relax.
Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any medication allergies and medical conditions that you may have.
Ask your doctor or pharmacist whether you need to stop taking any of your medications before the test.
You will be asked to remove all metal objects before having the scan, including jewellery. These objects interfere with the clarity of the X-ray images.
What can I expect after the test?
You can return to your normal activities after the CT scan has been completed.
If you have received a sedative to help you relax during the scan, you should not drive until the effects of the sedative wear off. Therefore, you may need someone to take you home.
Results
The results of the CT scan are images that can be displayed on a computer screen or permanently recorded on film. The radiologist will review the scan and send a report to your doctor. Sometimes a specialist will also review your scans. It may take several days to prepare the complete report before it is sent to your doctor.
Ask your doctor when your test results should be available. Your doctor can discuss these with you.