How does a calcium cardiac scoring CT scan detect heart blockage?

October 24, 2024 – 11 min read

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Your doctor recommended you get a cardiac calcium scoring CT scan so they can better understand how healthy your arteries are. This is a common scan for anyone who may be at risk of having a heart attack or a stroke in the future.

A cardiac calcium scoring CT scan gives your doctor accurate information about the condition of your arteries, so they can detect any heart blockages, and create a treatment plan for your specific condition.

In this article, we’ll tell you everything you need to know about how a cardiac calcium scoring CT scan helps detect heart blockages,, what to expect during your scan, and how to interpret your CT results. We’re here to walk you through it, step by step.

What is a cardiac calcium scoring CT scan?

A cardiac calcium scoring CT scan is a specialized test that helps assess the amount of calcium buildup, or plaque, in your heart’s arteries. This plaque is a combination of fat, cholesterol, and other substances, but when it hardens into calcium, it can narrow or block your arteries. 

Cardiac calcium scoring CT scans can give your doctor a clear picture of how much calcium is present in your coronary arteries. This information is crucial because calcium deposits are a marker of coronary artery disease, which can lead to heart blockages, or other serious heart conditions.

This scan provides a calcium score, which is a number that reflects how much calcium is detected. A higher score suggests a greater risk of coronary artery disease, while a lower score indicates less buildup. However, you should keep in mind that your calcium score is just one part of understanding your overall heart health.

How does a CT scan check for calcium deposits in the arteries?

A CT scan works by taking detailed images of your heart and its arteries, quickly capturing a series of cross-sectional images, which are then used to create a detailed view of the heart’s structure. 

These images show areas where calcium has accumulated in the artery walls, making it easier for your provider to see any plaque buildup that might be narrowing or blocking your arteries. During your CT scan, a computer analyzes the images, and calculates how much calcium is in your coronary arteries––that’s your calcium score.

Your cardiac calcium score and potential heart blockage

When your doctor orders a calcium cardiac scoring CT scan, it’s because they want a clearer picture of what’s happening inside your arteries. The results of this scan provide a calcium score, which plays a key role in determining whether you might have a heart blockage, and how significant that blockage could be. Let’s dive into what your calcium score means for your heart health.

What does your calcium score reveal about the condition of your arteries?

When plaque builds up in the arteries, it can harden into calcium, which is a sign of coronary artery disease. Your calcium score is a number calculated from your scan that reveals how much of this calcified plaque is present in your arteries. 

The higher your calcium score, the more plaque buildup your CT scan has detected, which could suggest that your arteries are becoming more prone to blockages. A lower score, or even a score of zero, suggests that you have a lower risk of significant blockages or coronary artery disease. 

Why could a high cardiac calcium score mean I’m at risk for a heart blockage?

Calcium deposits are a sign of long-term plaque buildup in the coronary arteries. As plaque accumulates, it reduces the flexibility of your artery walls, and narrows your arteries themselves. This narrowing can restrict the flow of oxygen-rich blood to the heart, increasing the risk of a blockage that could lead to a heart attack.

When your calcium score is high, it suggests that your arteries are more likely to be narrowed, and that you’re at an increased risk of coronary disease. Your healthcare provider will use this information, along with other factors like cholesterol levels and blood pressure, to help determine the next steps in your care.

What is a normal calcium score?

A normal calcium score is typically zero, meaning that no calcified plaque has been detected in your coronary arteries, and that your risk of heart blockage due to calcified plaque is very low. Your arteries are likely free from the type of hardened plaque that can lead to blockages and heart disease.

As your score increases above zero, the amount of plaque in your arteries increases: 

  • A score between 1 and 100 indicates some plaque is present, and that you have a lower risk for significant blockage. 
  • A score over 100 signals a higher amount of plaque, and your doctor may recommend further testing or treatments to manage your heart health, and to reduce your risk of a heart attack. 
Closeup of doctor's hands attaching electrodes on patient's chest

What to expect during your cardiac calcium scoring CT scan

If you’re scheduled for a cardiac calcium scoring CT scan, you may be wondering what the process will look like, and how to prepare for it. Knowing what to expect can help you feel more at ease going into the appointment, and we’re here to help you understand the whole process.

How should I get ready for my cardiac calcium scoring CT appointment?

Your doctor will give you personalized instructions to follow for preparing for your CT scan. You’ll want to choose comfortable clothing for your scan, like a tshirt and sweatpants, and you will be asked to remove any jewelry or metal objects that could interfere with the scan.

You may ask you to avoid eating or drinking for a few hours before the scan, and to avoid caffeine or smoking on the day of your appointment, as these can affect your heart rate. If you use a prescription medication or a supplement, then you should check with your doctor to ensure that it’s OK to keep taking it before your scan.

What will happen during my cardiac calcium scoring CT scan?

For your CT scan,  some small electrodes will be attached to your chest, to monitor your heart’s activity during the scan––this is completely painless and noninvasive. You’ll lie down on a cushioned table that your technologist will slide carefully into the CT scanner.

During the scan, you’ll be asked to lie very still, and to hold your breath for a few seconds while the machine takes images of your heart. The scanner will rotate gently around you, capturing the detailed images that will help your doctor assess any calcium buildup in your coronary arteries.

How long does a cardiac calcium scoring CT scan take? Can I go back to my normal routine after my scan?

A cardiac calcium scoring CT scan usually takes about 10 to 15 minutes, from start to finish, depending on your circumstances. The preparation and setup might take your technologist a little longer, but the scan itself is very brief. Most people are able to return to their normal routine immediately after the scan, so you can plan to head back to work or go about your daily errands, without any concerns.

Understanding the results of your cardiac calcium scoring CT

After your calcium cardiac scoring CT scan, you’ll receive a score that helps your doctor assess the amount of calcium buildup in your heart’s arteries. Your calcium score is an important piece of information, as it gives insight into your heart health, and about your potential risks of heart blockage. Let’s find out more.

What does a low, moderate, or high score mean for my heart health?

The calcium score is a numerical value that reflects how much calcified plaque is present in your coronary arteries. 

  • Low (typically 0-99): little or no calcium buildup, which indicates a lower risk of significant heart blockage at the time of the scan.
  • Moderate (100-399): some plaque buildup, meaning your heart is at a higher risk of narrowing arteries, which could lead to heart disease. 
  • High (400+): significant calcium buildup, which suggests a greater likelihood of blockages in the coronary arteries, raising the risk of heart attacks or other heart-related issues.

How will my doctor use my cardiac calcium score?

Your doctor will interpret your calcium score within the broader context of your overall health, risk factors, and symptoms. If your score is low, they may simply recommend regular monitoring of your heart health and maintaining a heart-healthy lifestyle. 

If your score is moderate or high, this could indicate that you may already have narrowing or blockages in your arteries, and your doctor might suggest more immediate actions, like lifestyle changes, medication, or further testing to assess the extent of the issue. 

How could my calcium score inform my future testing and treatment options?

A high calcium score can be a signal for additional tests to get a more detailed look at your heart’s condition. It can also guide your doctor’s treatment decisions, which could include medications that can lower cholesterol and manage blood pressure, or more advanced interventions as needed. 

If your score is low or moderate, your doctor might focus on preventive measures, like tailored lifestyle adjustments, such as improving your diet and increasing physical activity, to reduce the chance of heart disease developing or worsening. 

Your calcium score will be an essential part of managing your heart health, moving forward, helping to shape both short-term actions and long-term strategies for keeping your heart as healthy as possible.

Find a touchstone medical imaging center near you

How to schedule your CT appointment with us

Touchstone Medical Imaging offers CT scans in Arkansas, Colorado, Florida, Montana, Oklahoma, and Texas. 

Reach out to us at Touchstone, and we’ll help you schedule an CT appointment at an imaging center near you, today.

We’re here to help you get the answers you need.

Frequently Asked Questions (FAQ)

A: It’s a special test that shows how much calcium buildup, or plaque, is present in your heart’s arteries to assess the risk of coronary artery disease.  

A: The CT scan takes detailed cross-sectional images of your heart, revealing areas where calcium has accumulated in your artery walls.  

A: Your calcium score indicates the amount of calcified plaque in your arteries, with higher scores suggesting a higher risk of heart blockages.  

A: A high score indicates more plaque buildup, which can narrow your arteries and restrict blood flow to the heart, raising the risk of blockages.  

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A: A score of zero means no calcified plaque is detected, indicating a low risk of heart blockages from hardened plaque.  

A: You may need to avoid eating or drinking for a few hours and remove any metal objects before the scan, following specific instructions from your doctor.  

A: Small electrodes are placed on your chest, and you’ll lie still while the scanner takes images of your heart to detect any calcium buildup.  

A: Your doctor will use your score to assess your heart disease risk and recommend further tests, treatments, or lifestyle changes based on the results.