Coronary CTA (Coronary CT Angiography)

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 coronary 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 a more thorough examination of the blood vessels than catheter angiography. 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. Coronary CTA allows the radiologist to also view the blood vessel walls. Consequently, the radiologist can see plaque build up that may not be 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 doesn’t have coronary artery disease.  Because the test is non-invasive, coronary CTA will 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.

This page contains the following information about coronary CTA:

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Reasons for Having a Coronary CTA

Coronary CTA is used to evaluate coronary artery disease and evaluate a person’s risk of heart attack. Since coronary CTA is able to detect small amounts of plaque that are missed by other exams, it can detect very early disease, before a patient has symptoms. Also, coronary CTA allows the radiologist to evaluate other organs near the heart and possibly find other abnormalities, such as lung disease or enlarged lymph nodes.

Following are some of the circumstances under which coronary CTA may be used:

Coronary CTA does have limitations. It is not able to image people with irregular heart rhythms.  Very obese patients or those with heavily calcified arteries may also not benefit from this exam.

Risks Involved in a Coronary CTA

Coronary CTA is a very safe procedure; however, there are some minimal risks.

You could have an allergic reaction to the contrast material used during the procedure.

There is the risk of radiation exposure; however, it is well below the level that generally causes adverse affects. The radiation exposure is the same as other heart studies, such as a nuclear medicine stress test or angiography.  It’s also about the same as the background radiation a person receives by living in Colorado for 2 years.

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Conditions to Let Our Doctor Know About

In advance of your exam, let your Invision Sally Jobe radiologist or nurse know if any of the following circumstances apply to you:

Insurance Coverage

Coronary CTA is covered by many insurance plans. Check with your particular plan to be sure.

Exam Locations

Coronary CTA is performed by Invision Sally Jobe radiologists at the following Invision Sally Jobe partner hospitals in the Denver, Colorado area:

Please note:

Invision Sally Jobe is partially owned by Radiology Imaging Associates (RIA); consequently, your radiologist’s lab coat and your bill, if you receive one, may say RIA rather than Invision Sally Jobe.

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Scheduling This Exam

To schedule a consultation to discuss coronary CTA, please contact the hospital of your choice:

Preparation Guidelines

Following are the general preparation guidelines for coronary CTA. You may receive additional or differing guidelines based on your specific situation. Please contact us at 720-493-3406 if you have any questions.

What to Expect During Your Exam

Prior to the date of the procedure, you will fill out paperwork and consent forms so the radiologist will know your medical history.

For the procedure, you will lay on the CT scanner table. A nurse will start an intravenous (IV) line in your arm and measure your heart rate and blood pressure. If your heart rate is over 55 beats per minute, you will be given a drug to slow your heart rate. A slower heart rate allows for better images. Generally, the drug given is a beta blocker called Lopressor (metoprolol) unless you have asthma or emphysema. It is important to let the nurse know if you have either of these conditions.

Before going into the scanner, EKG leads are placed on your chest so the CT scanner will register your heart rhythm and be able to process the image data accurately. Contrast will be administered through the IV in your arm to make the arteries visible. Right before the scan, you will receive a nitroglycerin spray under the tongue. This ensures the coronary arteries are dilated, and don’t appear falsely narrowed.  Erectile dysfunction medications such as Viagra and Cialis can cause low blood pressure if taken with nitroglycerine, so it is important to avoid these medications for 24 hours prior to the scan. 

There are a total of three scans: a calcium score CT, a timing run, and the CT angiogram. You will be asked to hold your breath for 10-15 seconds while the images are taken. The timing run tells us how long it takes for the contrast to get from the IV in the arm to the coronary arteries.  This also helps to ensure the images are optimal.

The nurse will not stay in the room during the scan, but you can speak with him or her throughout the exam by intercom. You should not feel any pain or discomfort during the procedure. If you do, let the nurse know immediately.

Recovering from Your Exam

After the coronary CTA, you should drink a lot of water for the next 12 hours to help flush the contrast out of your system. 

Some patients get a headache after the scan. This is normal and should not be cause for concern.  Rarely, patients will develop a skin rash over the next few days as a reaction to the contrast.

Getting Your Exam Results

A radiologist experienced in the interpretation of coronary CTA will analyze the data and results from your exam. The specific results of the exam will be reported to your physician. In turn, your physician will pass the results onto you. Our radiologists and technologists will be happy to answer questions about the exam procedure itself; however, you will not receive your results at the time of your exam.

Coronary CTA is an imaging exam that uses a CT scanner to view the blood vessels of the heart Coronary CT angiography provides detailed images of the heart and its arteriesThe highly detailed images provided by cardiac cta allow a radiologist to better detect plaque build up