What Is Cardiac CT?

Cardiac computed tomography (to-MOG-rah-fee), or cardiac CT, is a painless test that uses an x-ray machine to take clear, detailed pictures of your heart. It's a common test for showing problems of the heart. During a cardiac CT scan, the x-ray machine will move around your body in a circle and take a picture of each part of your heart.

Because an x-ray machine is used, cardiac CT scans involve radiation. However, the amount of radiation used is small. This test gives out a radiation dose similar to the amount of radiation you’re naturally exposed to over 3 years. There is a very small chance that cardiac CT will cause cancer.

Each picture that the machine takes shows a small slice of the heart. A computer will put the pictures together to make a large picture of the whole heart. Sometimes an iodine-based dye is injected into one of your veins during the scan to help highlight blood vessels and arteries on the x-ray images.