A cardiac CT scan, also known as a coronary CT angiogram (CTCA), is the most accurate non-invasive test we have for looking directly at the coronary arteries — the blood vessels that supply the heart muscle. We arrange CTCA at trusted partner imaging centres in London, with full review and interpretation by Dr Nabila Laskar. It is the gold-standard test to rule out significant coronary artery disease in patients with chest pain or atypical symptoms, and it is increasingly used for cardiovascular risk stratification.
A CTCA is a high-resolution CT scan of the heart, performed after a small dose of iodine-based contrast is injected through a vein in the arm. Modern scanners take detailed 3D images of the coronary arteries in a single breath-hold. The scan can identify narrowings (stenoses), soft and calcified plaque, anatomical anomalies and bypass graft patency, with accuracy that approaches invasive coronary angiography for ruling out significant disease.
Before the scan, your heart rate is checked and a beta-blocker tablet may be given to slow it down for clearer images. A small cannula is placed in your arm. You lie on the scanner table and contrast is injected through the cannula — you may feel a warm flush for a few seconds. The scan itself takes only a few seconds and you will be asked to hold your breath. The whole appointment usually takes around 45 minutes. Dr Laskar then reviews the images and issues a full consultant report.
Avoid caffeine for 12 hours before the scan as it raises heart rate. Take all your usual medications unless told otherwise. Wear comfortable clothing without metal fastenings on the chest. You will be in the imaging centre for around 45 minutes in total. You can drive home and resume normal activities afterwards. The radiation dose is low — comparable to less than a year of natural background radiation in many cases.
A CTCA (coronary CT angiogram) is a non-invasive CT scan of the heart that uses intravenous contrast to produce detailed 3D images of the coronary arteries. It is the most accurate non-invasive test to rule out significant coronary artery disease.
It is most useful for patients with chest pain or atypical symptoms where coronary artery disease needs to be excluded, for cardiovascular risk stratification using calcium scoring, and for pre-operative assessment before major non-cardiac surgery.
It shows the coronary arteries, including any narrowings, soft and calcified plaque, calcium score, anatomy of bypass grafts, and the size and shape of the heart chambers.
Yes. Modern scanners use a low radiation dose, and the iodine-based contrast is very well tolerated. Patients with severe kidney impairment or a previous severe contrast reaction may not be suitable — Dr Laskar will assess this before booking.
The scan itself only takes a few seconds. Allow around 45 minutes at the imaging centre for preparation, the scan and observation afterwards.
An echocardiogram is an ultrasound scan that looks at the structure and pumping function of the heart and the heart valves. A cardiac CT looks directly at the coronary arteries that supply the heart muscle. They answer different clinical questions and are often complementary.