Computed Tomography (CT)

Instructions may vary depending on the type of CT, so please follow the instructions provided by the bookings office. If you’ve been instructed to avoid eating or drinking before your CT, you can still take your medications with a small sip of water. We recommend wearing loose-fitting clothing and avoiding jewelry or clothing with metal, as metal can interfere with the images and may hide important details. You may be asked to change into a hospital gown.

Your CT scan will be performed by a registered medical radiation technologist (MRT). MRTs are responsible for using advanced imaging and radiation techniques to provide accurate diagnostic information for your care. As both technical experts and frontline caregivers, they play a critical role in patient care, advocacy, and clinical decision-making. Click here to learn more about MRTs!

• A CT technologist is an MRT who specializes in operating CT scanners to produce detailed cross-sectional images of the body. To attain this specialization, MRTs pursue the Computed Tomography Imaging Certificate (CTIC) program offered by the Canadian Association of Medical Radiation Technologists (CAMRT).

A radiologist will review all of your imaging and provide a report to your referring healthcare provider. Radiologists are highly specialized physicians who play a pivotal role in diagnosing and monitoring diseases and injuries through advanced medical imaging. Their expertise is essential in guiding treatment decisions and ensuring optimal patient outcomes.

Contrast dye is a substance used during certain CT exams to enhance the visibility of specific areas within the body, such as organs and blood flow. This allows radiologists to better assess the structure, integrity, and function of the area being examined.

There are different types of contrast agents used depending on the clinical history and diagnostic question:

• Oral Contrast Agents: These are ingested by the patient and are commonly used to enhance imaging of the gastrointestinal (GI) tract, including the stomach and intestines.
• Iodine-Based Contrast Agents: These substances are commonly injected into blood vessels to improve the visibility of internal structures during imaging.

If you receive a contrast injection you will be required to remain in the department for 10-15 minutes for monitoring.

Although rare, allergic reactions can occur after receiving IV contrast. If you have a history of a contrast reaction, please inform your healthcare provider and CT technologist.

Following contrast, we recommend drinking plenty of fluids after your scan to help flush the contrast from your body.

If you are breastfeeding, current research shows that it is safe to continue breastfeeding after receiving iodine-based contrast. Please inform your technologist - they will provide you with any additional information you may need.

Please click here for more information on contrast agents.

The risk of developing cancer from a CT scan is very, very small. CT scans use radiation, but the doses are kept as low as reasonably achievable while still providing the images required for diagnosis.

The amount of radiation you receive will depend on the type of CT scan:

• Some scans use about as much radiation as you would get from 3 months of natural background radiation exposure from the sun and naturally occurring isotopes in the earth.

• Other scans may be equal to about 5 years of natural background radiation.

Your healthcare provider has recommended this test because the benefits outweigh the small risks. If you have any concerns, please speak with your healthcare provider.

Most patients with claustrophobia can tolerate a CT scan without any issues, as the machine is open and does not feel tight or enclosed. The scan itself is quick, often only lasting a few minutes inside the machine.

If you have concerns or anxiety about the scan, please speak to your healthcare provider before your appointment.

CT scans and MRIs both provide a comprehensive look inside the body to support the diagnosis of a disease or treatment, but they use different technology:

• CT scans use low-dose X-rays.

• MRIs use a large magnet and radiowaves.

Your healthcare provider will decide whether a CT scan or an MRI will give the clearest and most useful information to help understand your health concern.