CT Coronary Calcium Score Test: Heart Risk and Who Should Do it

What is a CT Coronary Calcium Score​ Test?

Coronary artery calcium (CAC) is a specific marker of atherosclerosis and helps predict cardiovascular disease outcomes. The CT coronary calcium score​ indicates the deposition of calcium within the coronary arteries during atherosclerotic plaques. The link between atherosclerosis and coronary calcium has been known since the 1970s, when calcium was detected by fluoroscopy and linked to cardiovascular conditions ².

In simple terms,

• The CT coronary calcium score test is a non-invasive imaging technique that helps quantify the total quantity of calcium deposition in the coronary arteries.
• The test helps radiologists to understand the presence and extent of calcified plaques, which potentially block arteries, causing heart attacks and other life-threatening cardiovascular outcomes.
• The test is beneficial for individuals with moderate heart conditions.

With a clear understanding of what a coronary calcium score is and how it is performed.

How is the Calcium Scoring Performed?

A CT coronary calcium score test uses non-contrast cardiac CT to measure calcium in coronary arteries and report it in the Agaston score. Protocols report an effective radiation dose of nearly 1 mSv for the coronary artery calcium CT ³.

Here’s a stepwise process for performing a CT coronary calcium score​:

Step 1: Basic Checks and Set-Up

The first step is to confirm your details, and the radiology team checks for safety parameters. Moreover, small ECG pads are placed on your chest so CTs can sync with your heartbeats. In addition, you can expect a basic checklist on what you must do for a clean scan.

Step 2: Breath-hold

You must lie flat on the CT table with your arms above your head. The next step is to hold your breath for a short interval. You must do two or three practice holds for accurate results.

Step 3: Image Capture on CT System

The scanning process is fast and involves a CT scan of the heart with a 3 mm slice thickness. The test is performed within 10 minutes and does not require any contrasts. A 128-slice cardiac CT scan provides high-quality imaging while minimising radiation dose.

Step 4: Calculation of Scores

The final step is to measure the amount of calcified plaques within each coronary artery and add the total scores. Trained radiologists review and assess image resolution, check for artefacts and report final scores to your cardiologist.

Let’s now understand how you can interpret CT coronary calcium scores.

Interpretation of Calcium Scores: Radiologist’s Perspective

CT coronary calcium scores provide an absolute numerical value, and factors such as age, ethnicity, and sex play a vital role in the final interpretation.

• A negative coronary CT score indicates the absence of arterial calcification. It suggests the absence of coronary artery disease.
• A positive test, on the other hand, helps predict the amount of calcification and is an indication for diseases such as myocardial infarction, commonly known as heart attacks.
• It is critical to undergo follow-up testing to evaluate potential diseases and conditions that may develop over time.

With a better understanding of score interpretation, let’s explore what you, as a patient, can experience during the diagnostic process.

What Will You Experience During the Procedure?

While preparing for the CT coronary calcium test, avoid caffeine and stimulants, as they can affect heart rate and image quality.

Here’s what you can expect during the test in simple terms:

• Before the Test: A radiology professional will provide a clear explanation of the procedure and ensure you have a comfortable experience.
• During The Test: You will need to lie on the table of a CT scanner, and technicians will place sensors on your chest to monitor your heart rate. The scanner will help you take multiple images of the coronary arteries within minutes.
• After The Test: In most cases, you can resume normal activities after the test, and the process is painless and requires no recovery time.

Next, let’s explore some potential benefits of the CT coronary calcium score test and how it helps detect cardiovascular disease.

Benefits of the CT Coronary Test

The CT coronary test helps detect early calcium buildup in coronary arteries before symptoms appear, supporting timely heart risk assessment.

Here are some of the benefits of the coronary test:

• Cardiac CT for calcium score assessment is a convenient, non-invasive modality for evaluating cardiovascular diseases and can help assess the risk of a heart attack.
• The overall process takes less time, causes no pain, and requires no contrast.
• You can return to normal activities right after the diagnostic procedure, providing a hassle-free experience.
• There is no radiation in the process, and the X-rays used have no side effects; therefore, repeated tests do not pose any health issues.
• Adding calcium scoring to traditional risk calculators improves risk prediction, leading to greater net reclassification (NRI) and reduce heart risks.

Also read: The Complete Guide to Digital X-Ray Imaging in Modern Radiology

Limitations of Coronary CT Procedures

Coronary CT procedures do not show soft plaque without calcium, so a zero score does not always rule out heart disease. Radiation exposure stays low but present, and this test does not replace clinical review, blood tests, or other heart assessments that your doctor may advise.

• There is always a possibility of cancer development with increased radiation exposure. CT scans provide accurate results, which are significant for treatment plans.
• If you are pregnant, it is essential to provide your radiologist with clear information before the test. Doctors do not recommend CT scanning as there is a chance of developing in unborn babies.
• High calcium scores may require further tests for accurate analysis of heart diseases, which may or may not provide your clinical values, and are often used to detect potential side effects.