Skip Navigation LinksTrillium Health Partners > Patient Services > Diagnostic Imaging > Computerized Tomography

 Computerized Tomography

​​A computerized tomography scan, often called a CT scan, is a relatively simple and non-invasive is a non-invasive medical test that uses x-rays and computers to produce multiple images of the body. Computerized tomography images of internal organs, bone, soft tissue and blood vessels provide greater detail than regular x-ray exams. 

Using this specialized equipment and the expertise of radiologists, problems such as cancers, cardiovascular disease, infectious disease, or musculoskeletal disorders can be identified.  The scans are performed by Medical Radiation Technologists who have advanced training in CT

Please tell your health care provider and the technologist if there is any possibility that you may be pregnant. Some CT exams require an injection of contrast or “dye”.  Please tell your health care provider of any previous reactions to contrast, allergies or other medical conditions like heart disease, diabetes or kidney disease.  Any of these conditions may change the type of scan we plan for you.

Contact Information

To book or follow up on  the status of your appointment, please contact:

Mississauga Hospital
Phone:  905-848-7554
Fax:  905-804-7926

Queensway Health Centre
Phone:  416-521-4069
Fax:  416-521-4014

Credit Valley Hospital
Phone:  905-813-4179
Fax:  905-813-3807

A completed and signed referral must be submitted by your health care provider prior to us booking an appointment for a CT scan.

Referrals

A referral from a doctor is required.

Resources for Patients & Their Families

Why Perform a CT Scan?
Computerized Tomography, or CT, scans CT scans of internal organs, bone, soft tissue and blood vessels provide greater clarity and reveal more details than regular x-ray exams.

CT scanning provides more detailed information on:

  • Head injuries, stroke, brain tumors and other brain diseases
  • Internal organs, bone, soft tissue and blood vessels
Using specialized equipment and expertise to create and interpret CT scans of the body, radiologists can more easily diagnose problems such as cancers, cardiovascular disease, infectious disease, trauma and musculoskeletal disorders.
How to Prepare for Your Procedure

If You Are Having a Head CT Scan
Please allow a minimum of 30 minutes for your appointment.
DO NOT drink for 2 hours prior.

If You Are Having an Abdomen/Chest Prep CT Scan
Please allow a minimum of 2 hours for your appointment.
DO NOT eat or drink for 2 hours prior.

If You are Preparing for Paediatric CT Scan
Please allow a minimum of 6 hours for your appointment if your child is being sedated.
Check with your Paediatrician/Family Doctor for specific instructions.

What to Wear
You should wear comfortable, loose-fitting clothing to your exam. You may be given a gown to wear during the procedure.

Metal objects including jewelry, eyeglasses, dentures and hairpins may affect the CT images and should be left at home or removed prior to your exam. You may also be asked to remove hearing aids and removable dental work.

Inform Your Doctor if
You should let your doctor know of any medications you are taking and if you have any allergies. If you have a known allergy to contrast material, or "dye," your doctor may prescribe medications to reduce the risk of an allergic reaction. 

Also let you  doctor know about any recent illnesses or other medical conditions, and if you have a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these conditions may increase the risk of an unusual adverse effect. Women should always let their doctor and the CT technologist know if there is any possibility that they are pregnant.

What to Expect from Your Procedure

The technologist will begin by positioning you on the CT examination table, usually lying flat on your back or possibly on your side or on your stomach. Straps and pillows may be used to help you maintain the correct position and to hold still during the exam. 

If contrast material is used, it will be swallowed, injected through an intravenous line (IV) or administered by enema, depending on the type of examination.

Next, the table will move quickly through the scanner to determine the correct starting position for the scans. Then, the table will move slowly through the machine as the actual CT scanning is performed.
You may be asked to hold your breath during the scanning. Any motion, whether breathing or body movements, can lead to artifacts on the images. This is similar to the blurring seen on a photograph taken of a moving object.

When the examination is completed, you will be asked to wait until the technologist verifies that the images are of high enough quality for accurate interpretation.

CT scanning of the body is usually completed within 30 minutes.

What will I experience during and after the procedure?
CT exams are generally painless, fast and easy. With modern CT, the amount of time that the patient needs to lie still is reduced.
Though the scanning itself causes no pain, there may be some discomfort from having to remain still for several minutes. If you have a hard time staying still, are claustrophobic or have chronic pain, you may find a CT exam to be stressful.

If an intravenous contrast material is used, you will feel a slight pin prick when the needle is inserted into your vein. You may have a warm, flushed sensation during the injection of the contrast materials and a metallic taste in your mouth that lasts for a few minutes. Some patients may experience a sensation like they have to urinate but this subsides quickly.

Occasionally, a patient will develop itching and hives, which can be relieved with medication. If you become light-headed or experience difficulty breathing, you should notify the technologist , as it may indicate a more severe allergic reaction. A radiologist or other physician will be available for immediate assistance.

If the contrast material is swallowed, you may find the taste mildly unpleasant; however, most patients can easily tolerate it. You can expect to experience a sense of abdominal fullness and an increasing need to expel the liquid if your contrast material is given by enema. In this case, be patient, as the mild discomfort will not last long.

When you enter the CT scanner, special lights may be used to ensure that you are properly positioned. With modern CT scanners, you will hear only slight buzzing, clicking and whirring sounds as the CT scanner revolves around you during the imaging process.

You will be alone in the exam room during the CT scan. However, the technologist will be able to see, hear and speak with you at all times. 
After a CT exam, you can return to your normal activities.