What is a CT scan?

A CT scan or a computerized tomography combines a series of X-ray views taken from many different angles and computer processing to create cross-sectional images of the bones and soft tissues inside the body.

The resulting images can be compared to looking down at single slices of bread from a loaf. Your doctor will be able to look at each of these slices individually or perform additional visualization to view your body from different angles. In some cases, CT images can be combined to create 3-D images. CT scan images can provide much more information than do plain X-rays.

A CT scan has many uses, but is particularly well suited to quickly examine people who may have internal injuries from car accidents or other types of trauma. A CT scan can be used to visualize nearly all parts of the body.

During the scan everybody except for the patient will leave the room. The radiographer will still be able to communicate with the patient, and vice-versa, through an intercom. If the patient is a child, a parent or adult might be allowed to stand or sit nearby - that person will have to wear a lead apron to prevent radiation exposure.

What ate CT scans used for?

CT scans can be used to diagnose and monitor a variety of different health conditions, including brain tumours, certain bone conditions, and injuries to internal organs such as the kidneys, liver or spleen. They're also now being used to look at the heart.

They're also often used to look inside the body before another procedure takes place, such as radiotherapy treatment or a biopsy (where a small sample of tissue is taken so that it can be examined under a microscope).

Your scan results won't be available immediately. A computer will need to process the information from your scan, which will then be analysed by a radiologist (a specialist in interpreting images of the body).

CT scans are only used when the doctor responsible for your care decides there's a clear medical benefit. Although CT scans are generally safe, they do expose you to slightly more radiation than other types of imaging tests. The amount of radiation you're exposed to can vary depending on the type of scan you have. In most cases, the benefits outweigh any potential risks because a CT scan can provide your doctor with much clearer images than those produced by a normal X-ray.

However, special attention should be given to the patient in the following cases:

(1 Pregnancy: Any woman who suspects she may be pregnant should tell her doctor beforehand. CT scans are not recommended for pregnant mothers because of the risk that X-rays might harm the unborn baby

(2) Claustrophobia: Patients who suffer from claustrophobia need to tell their doctor or radiographer beforehand

(3) Breastfeeding: Mothers should avoid breastfeeding their babies for about 24 hours after a CT scan if an iodinated intravenous dye was used...