CT Coronary Angiography
Computerised Tomography (CT) coronary angiography is a diagnostic imaging test that allows us to look at the arteries that supply blood to your heart. You may need a CT coronary angiogram if your doctor wants to diagnose the cause of chest pain or other symptoms.
What is a CT Coronary Angiogram?
A CT Coronary Angiogram is performed using a CT scanner and involves the use of x-rays to create detailed cross-sectional 2D and 3D images of the heart and its blood vessels. These images are viewed and interpreted by specialist cardiothoracic radiology consultants to identify any abnormalities that may reveal the cause of symptoms such as chest pain or the early signs of coronary artery disease.
Why is a CT Coronary Angiogram performed?
A CT Coronary Angiogram may be used for several reasons but is mainly used to check for narrowed or blocked arteries around the heart (coronary artery disease).
Sometimes, a CT Coronary Angiogram will be performed simultaneously alongside another CT test called a CT Calcium Score. This scan is a specialised test that provides pictures of the heart that can help your doctor detect and measure calcium-containing plaque in the coronary arteries. These measurements can allow your doctor to identify possible coronary artery disease before you have signs and symptoms.
What does a CT Coronary Angiogram involve?
Unlike a conventional angiogram, a CT Coronary Angiogram is a non-invasive and painless imaging test.
You will be asked to lie down on your back on a comfortable CT bed. To help us achieve clear pictures, we will ask you to hold your breath for a short time. We will also use a medication called a beta-blocker to slow your heart rate safely. Doing so will allow us to provide clearer images of the heart on the CT scan.
After the scan we will check your blood pressure and heart rate and you will then be able to return to normal daily activities.
How do I prepare for the scan?
On the day of a CT Coronary Angiogram scan, it is very important to have no caffeine (tea, coffee, chocolate and many fizzy drinks). Caffeine will increase the heart rate and may mean we are unable to perform the scan. Patients are also asked not to smoke for at least 4 hours before the scan.
It is also important that patients have not taken Viagra (sildenafil) or similar drugs in the 24 hours before a CT Coronary Angiogram. If you take this regularly, please check with your doctor that it is safe for you to stop taking this for 24 hours.
Otherwise, you should continue to take all your regular medication.
Patients of childbearing potential are also asked to contact us if they suspect that they may be pregnant, OR if the appointment we have given you is more than ten days after the start of your last menstrual period. This test uses radiation, and there is a risk to the unborn baby from x-ray exposure. When you arrive, we will ask when your last period started. If it is more than ten days earlier, your appointment will be postponed.
Heart Rate Control
Before a cardiac CT scan, your referrer may prescribe you some medication called a beta-blocker to lower your heart rate. This allows us to acquire better quality and more diagnostic images.
If this is necessary, your doctor will provide relevant information and a prescription for you to obtain some tablets.
Is a CT Coronary Angiogram safe?
During a CT Coronary Angiogram, you will be briefly exposed to a small and highly focussed amount of radiation in the form of x-rays. For this reason, we would typically not use CT for pregnant patients or young children unless absolutely necessary.
Our state-of-the-art scanner uses a lower dose than many other CT scanners in use. In fact, the doses used for CT scanning, in general, are so low that the risk of developing side effects from the radiation is too small to be reliably measured. Nevertheless, our skilled staff are trained to ensure that radiation is only used when there is a clear medical benefit and that all doses are kept as low as possible.
Whilst rare, it is possible that you could have an allergic reaction to the x-ray dye or the beta-blocker medication used for the scan. We will go through a safety checklist with you before your scan to identify any reason why you should not have the contrast dye. However, please talk to your doctor if you are concerned about having an allergic reaction.
When will I get my results?
The images from your CT Coronary Angiogram are ready for the radiologist to view immediately after your scan. You will see your pictures using a health portal that we will set up for you. The radiologist will then analyse the images and write a report within 24 hours which will be sent to your doctor.