Coronary CT Angiography

Coronary CT angiography is a specialised heart scan performed on a fast CT scanner. It looks specifically at the coronary arteries, the small vessels that supply blood to the heart muscle, and the structures of the heart itself. Unlike a conventional, invasive angiogram that requires a catheter to be passed up to the heart, this examination is carried out from outside the body, so it is far less involved for the patient. The scanner builds detailed three-dimensional images of the heart and its vessels, which a specialist then studies.

The patient lies on a table that passes through a ring-shaped CT scanner. A contrast agent is usually injected through a small vein to make the coronary arteries stand out clearly on the images. Because the heart is always moving, the scan is timed precisely to the heartbeat and captured very quickly, often in a single short breath-hold, so the pictures stay sharp. The scanner records images from many angles and the computer combines them into clear cross-sections and three-dimensional views. It can also calculate a calcium score, a measure of how much calcified plaque is present, which acts as a marker of heart risk.

The main use of coronary CT angiography is to assess coronary artery disease, showing plaque in the artery walls and the narrowings it causes that can limit blood flow to the heart. The calcium score it provides helps gauge a person's risk of future heart problems. Beyond the coronary arteries, it is also used to examine pericardial disease, congenital heart conditions present from birth, masses within or around the heart, and conditions affecting the heart valves. It is often chosen for people with chest symptoms or risk factors, as a clear, non-invasive way to look at the heart.

The key benefit is a detailed look at the heart's arteries without a catheter, which makes the examination quick, comfortable and low-risk compared with invasive angiography. The calcium score adds useful information about long-term risk. The scan is painless. The patient lies on a table, a contrast agent is usually given through a small vein and may cause a brief warm feeling, and the person is asked to stay still and hold their breath for a few seconds. The scan itself takes only a short time. There is no recovery period, and most people go home soon afterwards while a specialist reviews the images and reports to the treating doctor.