For Patients

What is CT?

CT stands for X-ray Computed Tomography and ranks as one of the top five medical developments in the last 40 years. It is a diagnostic imaging device that uses X-ray radiation to produce computer-processed tomographic images, allowing the radiologist to visualize anatomic structures of your body. CT has proven so valuable as a medical diagnostic tool that the 1979 Nobel Prize in Medicine was awarded to its inventors.

How CT works and differs from a conventional x-ray

During a radiographic procedure, a stationary machine emits x-rays that penetrate the body to produce a single, one-dimensional image on an imaging medium, such as film.

During a CT scan, the x-ray source rotates around the body in order for multiple images to be collected from different angles. These scans are then combined and reconstructed by a computer to produce a detailed image of the patient’s anatomy. Through this procedure, in a CT image, overlapping structures are eliminated, making the internal structures more apparent compared to a conventional X-ray image.

What are the benefits of CT? 

CT scans assist radiologists in diagnosing a variety of medical conditions, such as internal injuries, inflammation, vessel pathology or tumours. The referring doctor will use the medical information provided to more effectively manage a patient’s condition, by for example reducing the need for exploratory surgeries, guiding treatment of common conditions, such as injury, cardiac disease and stroke, improving cancer diagnosis and treatment.

Sources

Radiation Dose Chart 
http://www.imagewisely.org
http://www.eurosafeimaging.org
https://www.ucdmc.ucdavis.edu/radiology/UCDHS_CT_FAQ_v1.pdf

Questions about the procedure

What can I expect before my CT scan?

You will be given a detailed consent form at the centre, which you should read carefully.

However, to help you prepare, we have created an animation video, which guides you through the process steps:

What can I expect during my CT scan?

Most CT scans take up to 15 minutes, during which you will be lying on a padded table. You may be asked to lie on your stomach, back or side, and to hold your breath for a few seconds or stay very still. During the study, you may hear humming noises or feel the table move slowly through the CT scanner. For certain exams a contrast dye will be used. In that case, further information will be given to you prior to the exam.

What if I still have questions or concerns about my CT scan?

Please feel free to discuss any remaining questions or concerns with either your referring doctor or with the staff of the Radiology Department.