Cardiac computed tomography (CTA or cardiac CT) is a diagnostic test that provides images of the heart and great vessels. This is a relatively non-invasive and low risk procedure. With its superior images, cardiac CT plays a significant role in evaluating certain cardiovascular diseases. In general, a CTA is used to evaluate a patient for an aortic disease, cardiac masses and pericardial disease. It is also useful in assessing plaque within the vessels surrounding the heart.