A computerised tomography scans uses multiple x-rays that is then processed in a computer to create detailed images of inside of the body. Some scans may involve injecting contrast just before that. Any allergies or kidney problems should be mentioned to the surgeon who is ordering the test and to the radiographer who is performing the scan. Besides the scan is not advisable for pregnant woman unless it is an emergency as there is a small chance that the x-ray could harm the baby.
The scan usually takes around 10 to 20 minutes and you will usually be lying on your back on a flatbed that passes into the scanner. The scanner usually has a ring that rotates around a small section of your body as you pass through it. Unlike MRI scan the CT scan rarely cause claustrophobia.
The amount of radiation you are exposed during a CT scan varies and is dependent on the amount of body that is scanned. The risk of developing cancer is less than one in 2000. The benefits and risks of having a CT scan should be discussed with the ordering surgeon beforehand.