How CT Scans Work

A CT (Computed Tomography) scan is a more sophisticated type of X-ray, produced with a dedicated machine.

The scanner is linked to a computer that takes the x-ray information and produces images of your body in “slices”- almost like a loaf of bread.

The Radiographer uses the computer to build up a picture of the whole area showing both soft tissue and bone; these images are then transmitted to one of our Radiologists, who will read the images and forward a written report to your Doctor.

Before your examination

Any specific preparation instructions will be advised at the time of booking. Generally the following preparations apply:

Head, neck, chest, abdomen and pelvis scans:

Nothing to eat for two hours prior to your appointment time. You may drink a small amount of water.

Renal scans:

It is desirable to have a full bladder for this scan. Please do not empty your bladder within the one hour prior to your appointment.

Spinal and musculoskeletal scans:

No preparation required.

Some CT examinations require an injection of iodinated contrast medium into an arm vein, to allow imaging of the blood vessels and vascular tissues. If required, this will be discussed prior to the injection and you will be asked to complete a questionnaire and provide consent.

During your examination

You may be asked to change into a gown and/or remove jewellery.

You will lie on a table which is slowly moved into the doughnut shaped CT unit. Housed within the CT is an X-ray tube which rotates around you. Detectors capture the X-rays passing through the examined area for the computer to interpret into images. You may be asked to hold your breath for a few seconds during the scan.