A CT scan (sometimes known as a CAT scan or ‘computerised axial tomography) is used to diagnose and explore a wide variety of conditions such as problems with internal organs, blood vessels, and bones. They can also be used to monitor on-going conditions.
During the CT scan, you will usually lie on your back in the scanner. Unlike an MRI scan, the scanner is shaped like a doughnut ring which only surrounds part of your body, meaning you shouldn’t feel claustrophobic.
As with conventional X-rays, the radiographer will operate the scanner from a different room. You will be able to speak to them and vice versa during the procedure via a telecom system.
You will need to remain still during the scan, otherwise the images may be blurry. You may be asked to hold your breath, breathe in, or breathe out during the procedure.
Sometimes, a contrast dye is injected into the back of your hand during the procedure to improve the images.
The scan usually lasts between 10 and 30 minutes.
You will be advised beforehand whether you need any special preparation for your scan. Sometimes, you may be asked not to eat or drink beforehand.
If you are pregnant, or suspect you are pregnant, you may not be able to have the scan due to the small risk of radiation could harm your unborn baby.
It is a good idea to wear loose clothing, and remove any jewellery beforehand.
You will be able to continue your normal daily activities, including driving, after your CT scan. If you have been injected with contrast dye, you may be asked to stay a little longer to ensure you have no adverse reactions to the dye.
The images from your CT scan are then sent to a radiologist to examine.
A CT scan does expose you to radiation, however the dose is very small. Your consultant will discuss this with you beforehand.