A cardiac CT is a specialized form of an x-ray scan. CT stands for computed tomography, and tomography is the use of x-rays to create images of the body in cross-section.

During a CT scan, the x-ray machine moves around the patient's body in a circle taking pictures along the way. Each picture is a small slice of the heart and surrounding blood vessels. The computer then combines these images to create a three-dimensional view that is so clear and detailed, physicians can detect even the most subtle early indications of coronary disease.

The cardiac CT is most often used to evaluate common cardiac symptoms such as chest pain, shortness of breath, palpitations, dizziness or syncope (fainting).

The cardiac CT is a painless exam. During the procedure, the patient lies flat on a table that passes through a circular machine. The patient's head and feet are positioned outside of the machine on either end. Only about 15 inches of the patient's body are actually inside the machine (even claustrophobic patients usually feel comfortable inside a CT scan machine). The scan typically takes about ten minutes.

For some patients, the cardiac CT is performed with intravenous contrast or dye (the use of dye depends on the reason for the exam and will be indicated by the referring physician). If contrast or dye is required for the exam, it will be administered by injection. The dye is used to highlight particular blood vessels.