How Is a CT Coronary Angiography Done?

Coronary computerized tomography angiography (CCTA) is a heart scan or imaging test that helps diagnose plaque buildup and consequent narrowing of the coronary arteries (the blood vessels that supply the heart). 

During a CCTA scan, you may receive an iodine-containing material (contrast) as an intravenous injection to ensure the best possible images of the coronary blood vessels.

It uses powerful X-rays and produces multiple cross-sectional images or pictures of the inside of the body which can be viewed on a computer monitor, printed on film or by a 3D printer or transferred to a CD or DVD. 

The procedure is performed to diagnose many heart conditions. These include:

• Diagnosis of coronary artery disease (CAD)
• Diagnosis of narrowing of the existing stent in cases of previous stent placement
• Evaluation of coronary bypass graft patency

A coronary CT angiography (CCTA) is generally done in the doctor’s office or hospital. The procedure, on average, takes 15 minutes to one hour to complete. CCTA is quite similar to a normal CT scan, the difference being the CT scanner speed and the use of a heart monitor to determine the heart rate.

Before the test

• You may be asked not to eat or drink anything for a few hours. 
• You must tell your doctor of any medications you are on or allergies you may have. 
• You need to inform your doctor of any medical conditions or illnesses you may have.
• You may be asked to avoid diet pills, Viagra (or any similar medicines), and caffeinated drinks, such as coffee, tea, energy drinks, or sodas for 12 to 24 hours before the test.
• The night before the procedure, you may be given medications (e.g., beta-blockers) to optimize the quality of the scan. 
• You must tell your doctor if you are pregnant or breastfeeding.
• Your doctor will perform your physical examination and explain the procedure in detail.
• You may be asked to shave your chest hair.
• You may be asked to give your written consent for the procedure.

During the test

• You may need to wear a hospital gown.
• Metal objects such as jewelry, dentures, hairpins, and eyeglasses should be removed.
• The CT scanner machine is typically a large, donut-shaped structure with a short tunnel in the center. 
• You will lie on a narrow examination table that slides in and out of the short tunnel.
• The X-ray tube and electronic X-ray detectors rotate around you in a ring, called a gantry.
• A technologist operates the scanner and monitors your exam in a separate control room from where they can hear and talk to you via a speaker and a microphone. 
• The technologist will clean small areas on your chest and place small, sticky discs (electrodes) attached to an electrocardiography monitor. 
• They will insert an intravenous line in your arm to administer contrast material during the procedure. 
• You may be given other medications like beta-blockers and nitroglycerine to improve visualization.
• You may be asked to raise your arms over your head during the exam to improve image quality.
• The examination table will move several times during the test.
• You may be asked many times to stay still and hold your breath for a few seconds during the scanning. 

After the examination

• You will be asked to wait until the technologist verifies that the images are of good quality.
• Your intravenous line is removed.
• The radiologist interprets your results and issues a report.

CT coronary angiography or CCTA is a better procedure as compared to other imaging studies for the heart blood vessels as it has many benefits:

• CCTA is not invasive (instruments are not introduced inside the body) and thus has fewer complications and faster recovery.
• The imaging provides a clear view of bones, soft tissues, and blood vessels at the same time. 
• It provides very detailed images of many types of tissue.
• The examination is fast and simple.
• It is cost-effective.
• The imaging is less disturbed by patient movement, unlike magnetic resonance imaging (MRI).
• Unlike MRI, CCTA can be performed if you have an implanted medical device of any kind.
• No radiation remains in the body after the CCTA examination.
• There are no immediate side effects.