What Coronary CT Angiography Is
CT angiography is an imaging exam that uses x-rays to examine the blood vessels in various parts of the body. A scanner is used to take images which are assembled into three-dimensional views of the blood vessels using state-of-the-art computer software. When used to view the arteries of the heart, this exam is referred to as coronary CTA (or cardiac CT).
Catheter angiography has been used to examine coronary arteries for years. With catheter
angiography, a very thin, long tube is threaded through the groin arteries to the heart.
Coronary CTA is a much less invasive procedure. Additionally, coronary CTA
allows the radiologist to view the blood vessel walls. With catheter
angiography, only the lumen can be examined. The lumen can often look normal when the
blood vessel has actually expanded to compensate for the plaque build up. With coronary CT angiography,
the radiologist may see plaque build up that is not visible with a catheter angiography.
CT (computed tomography) was originally developed in the 1970s to see the body's organs without having to perform surgery. The heart and coronary arteries are the last area of the body to be imaged with CT, primarily because the beating heart caused blurry images. However, the latest generation of CT scanners is fast enough to capture motion-free images of the coronary arteries for the first time.
A negative coronary CTA is a strong indicator that the patient does not have coronary artery disease. Because the test is non-invasive, coronary CTA will likely become the first line diagnostic test to evaluate for the presence or absence of coronary artery disease. In patients with acute cardiac symptoms or angina, however, catheter angiography is still preferred because intervention, such as stenting a narrowed artery, can be performed at the same time.
Also, a number of studies have shown that important findings outside the heart show up on coronary CTA. More than one in ten scans will have such findings, including an unsuspected lung cancer or other lung disease, enlarged lymph nodes, or abnormalities in the liver. It is therefore important that you have a doctor qualified to read CT scans - a radiologist - review your coronary CTA.
Coronary CTA may also be helpful in patients with unclear causes of chest pain, which is a common patient complaint in doctors' offices and emergency rooms. There are many causes of chest pain and they can be difficult to tell apart. CT angiography may be helpful to rule out the most dangerous causes of chest pain, such as blockage or abnormality of a coronary artery, a pulmonary embolism, or an aortic aneurysm or dissection. In addition, sometimes stress test results are uncertain. In these cases, CT angiography can evaluate the coronary arteries and spare the patient a surgical angiogram.
RIA radiologists interpret coronary CT angiography exam results at several Denver area hospitals.