What is a CT Scan?
A CT Scan is a complex imaging device which uses X-Ray radiation to allow very thin three dimensional slices to be imaged of areas of your body. Once acquired, these thin slices can be manipulated to construct complex high resolution imaging of your body.
Cardiac CT scans use an ECG to image your heart between beats in order to obtain sharp diagnostic images. Our Radiologists and Cardiologists use these images to assess for any blockages that could lead to heart disease.
The CT Scanner itself is a ring or doughnut shaped machine with a moving patient bed attached.
How do I prepare for my CT Scan?
You will be required to fast for prior to the scan as an injection of IV Contrast will be required for the procedure. Our staff will also require you to complete an extra form to ensure there are no medical contraindications to administering IV Contrast.
What will happen during my CT Scan?
You will be asked to change into a gown prior to your CT Scan and you will be required to remove any metal objects. Prior to commencement of the scan a staff member will take you aside to check your heart rate and blood pressure. These measurements are important to ensure the best possible images of your heart are obtained.
The Radiographer will then help you onto the CT bed and into the correct position for your scan. For a CT Scan of your heart, you will generally be lying on your back with your feet towards the scanner. The Radiographer may also use foam pads or other devices to help position you for the most effective scan possible. ECG dots will be also need to be placed on your chest and it may be necessary for staff to shave the area to ensure a good ECG signal is received.
Staff will need to insert an IV cannula in order to administer the contrast during the scan. The contrast injection often produces several short term side effects, most notable you may experience a warm sensation through your body. Depending on your heart rate at the time of scanning our Doctors may also elect to administer a beta blocker intravenously. Beta Blockers temporarily slow your heart rate, this prevents blur from the motion of your heart interfering with image quality.
During the scan itself the Radiographer will leave the room to operate the machinery. The table will move through the gantry (the centre of the machine) as images are obtained. This process may be repeated several times until all necessary imaging is acquired. During the scan you will be expected to remain very still and will be required to control your breathing.
Is a CT Scan safe?
CT Scans use X-Ray radiation in order to acquire imaging of the body. Your Doctor and our staff will ensure that any potential risks from a scan are always significantly outweighed by the benefits to you.
Our staff will take all steps to reduce radiation doses from CT Scanning to lowest possible levels to achieve an image. Our CT Scanner also uses the latest technology available to achieve the lowest possible dose while maintaining high quality and diagnostic imaging.
Occasionally, mild allergic reactions to the IV contrast or Beta Blocker can occur. These mild reactions include a rash, hives or sneezing and generally occur at the time of the scan. More severe allergic reactions have occurred but are extremely uncommon. We have equipment and highly trained staff onsite to deal with any reaction should it occur.
How long will a CT Scan take?
The scans themselves, when you will be expected to hold your breath, will often take less than 10 seconds. Generally, for CT of the coronary arteries the entire procedure will range from 20 to 40 minutes. If you were injected with IV Contrast, you will be asked to wait for 15 to 30 minutes after your procedure with the cannula still in place as a precaution.
Are there any after effects from a CT Scan?
There are no after effects from a CT Scan of the coronary arteries.
If contrast media has been injected it will be excreted naturally with no effects. You may resume normal activity after the scan.
If you have had a beta blocker administered in the course of the scan, it will be necessary to make arrangements for transport home as we will ask that you not drive for 8 hours after the procedure.