A CT coronary angiogram or "CTCA" is a scan that records pictures of the heart arteries. Before the pictures are taken, dye is injected into a vein (usually in the arm). The dye highlights any blockages in the coronary arteries, helping to diagnose coronary artery disease.Current literature suggests CTCA may have greatest utility in patients where the probability of coronary disease is low or intermediate due to high negative predictive value – i.e. it is an excellent ‘ruleout’ test. There are some limitations with the CT scan that need to be considered and requirements to slow the heart rate so that the quality of the images is high. Professor Barlis discusses some of the uses of the CT scan and how it may provide relevant details about the arteries around the heart.