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CT Scan Calcium Score

A calcium score test can determine whether you need treatment to prevent a heart attack or stroke in the future by showing your healthcare provider how much calcium is in your coronary arteries. Calcium in the arteries can indicate a build-up of fatty substances within them that can narrow or block them, leading to a life-threatening condition.

The calcium score test is most helpful for people with mid-range results to help them change before the arteries get too full. This test is non-invasive and quick for the majority of patients, and you can often resume your everyday activities right after.

How do CT scan calcium score tests work?

A calcium score test uses a computed tomography (CT) scan to take images of your heart and the surrounding tissues. Any area that has calcified plaque within the arteries will show up on the scan so your medical professional knows how to diagnose you.

The CT scan uses a circular-shaped machine that takes images of your chest from all angles. This allows the computer to create cross-sectional images to give doctors a better view of the inside of your heart and chest without invasive procedures.

The images, when pieced together, can turn the scans from 2D to 3D, making it so the doctor is almost looking directly into your chest rather than at allusive 2D images. This helps the majority of medical professionals reach a diagnosis and treatment plan much faster, so you don’t have to worry about your coronary artery calcium scoring for as long without treatment.

The majority of cardiac CT scans require you to be injected with a contrast medium, which is a dye that helps see the coronary arteries easier on the created images.

Why might you need a CT scan calcium score test?

A calcium scoring test is an effective method for assessing patients who are at borderline risk of heart disease. It’s generally offered to patients between the ages of 40 and 70 with an increased risk of heart disease but who don’t have symptoms. It’s considered a preventative measure rather than an actual treatment for heart disease.

People who are at a higher risk of heart disease include those who:

  • Have a family history of heart disease
  • Have used tobacco products, either previously or presently
  • Lead an inactive lifestyle
  • Have a history of high cholesterol, diabetes, or high blood pressure
  • Are overweight or obese (with a BMI higher than 30)
  • Have other risk factors that are less traditionally seen in patients

Some people are offered calcium score testing if high cholesterol runs in the family, even if they’re younger than 40 years old.

Calcium score tests cannot detect all forms of coronary artery disease. For example, soft plaque atherosclerosis is not always detectable through coronary artery calcium scoring. So this test isn’t always absolute when predicting a heart attack or stroke. Instead, it’s a tool that your doctor can use to determine if you need more preventative treatment.

How to prepare for your CT scan calcium score test

To prepare for your coronary artery calcium scoring, there are a few things you’ll likely need to do beforehand. Your hospital will have specific details on what you need to do to prepare, so when in doubt talk to your doctor. However, here are a few things your doctor might tell you to do before your scheduled CT scan.

  • Make a note of any allergies you have to tell your radiologist, as well as any medications you’re taking and if you could be pregnant

  • Prevent eating, drinking, or using any caffeine and tobacco products for four hours before your calcium score test

  • Remove any metal from your body, including jewellery, piercings, and glasses

What to expect from your CT scan calcium score test

During the scan

When you arrive at the radiology department of your hospital and are called into your appointment, you’ll be asked to change into a hospital gown and lie down on the scanner table in the CT scanning room. 

Once you’re lying down on the table comfortably, your doctor will clean and potentially shave three small areas on your chest. This is where they’ll stick the small electrode patches and attach them to an electrocardiogram monitor (EKG). This will chart the electrical activity within your heart during the test and allow your doctor to time scans with your heartbeat. 

Most arterial CT scans require a contrast medium to be administered beforehand so your radiologist can monitor your heart and arteries. This is often given intravenously, although some doctors might give it as a drink or barium meal. The dye contains iodine, so it might not be given to you if your doctor suspects an iodine allergy. 

During the calcium score test, you’ll feel the table move beneath you as you’re moved into the scanner. This can be a little disorientating but you should be perfectly safe. You’ll be given headphones with a microphone fitted so you can hear and talk to your radiologist who will be in the next room over. 

The machine will then take a series of images synchronised with your heartbeat. You’ll be asked to remain still for this time (it won’t be too long) and you might need to hold your breath for 10 to 20 seconds. This will make sure the images are as clear and crisp as possible to maximise the efficiency of the calcium score testing. 

The majority of CT scans will take around 15 to 20 minutes, but most of this will be taken up with preparation and talking you through the process. The actual CT scan will only take a few minutes. 

As most coronary artery calcium scoring tests are planned outpatient appointments, you should be able to walk and go home straight after your appointment.

After the scan

Coronary artery calcium score testing shouldn’t hurt or cause any discomfort to you. Some patients report feeling a little nervous about lying on the table and having the loud machine working around them, but it shouldn’t leave them with any lasting effects. You may feel discomfort if you were given the control medium intravenously.

Some hospitals have a policy to keep you for 30 minutes after the CT scan to make sure you don’t have an allergic reaction to the contrast medium. In rare cases, the dye can send patients into anaphylaxis shock if they’re allergic to it. If you notice you’re having trouble breathing or have a new rash after being administered the contrast medium, you should tell your doctor straight away.

Once your scan is finished, you should be able to go home and resume regular activities. The exception to this is if you were given a sedative beforehand. Some hospitals offer a sedative to patients who suffer from claustrophobia, so if you have the sedative you’ll need to be kept for a few hours until it wears off.

Results should be ready within 48 hours, but every hospital has different policies and timeframes. Your doctor will be able to tell you when you can expect your results.

What are the benefits of CT scan calcium score tests?

A cardiac CT scan is an advanced imaging technique that creates detailed images of the heart and surrounding structures to help your doctor identify conditions that influence the heart’s health and functionality. We’ve detailed some of the benefits of CT scans below:

  • CT scans are non invasive and take less time than exploratory surgery, so you can often walk straight out of your appointment and get on with everyday activities
  • Calcium scoring can detect early signs of heart disease so you can get a headstart on preventative measures and treatments
  • A cardiac CT scan can take images of all of the internal organs and structures in your chest so your doctor has a good view of your entire chest, helping to diagnose other potential ailments
  • The results are generally delivered quickly and efficiently to help people who are at higher risk of heart disease learn whether there is cause for concern or not


Is a CT calcium score worth it?

A calcium score test can give your doctor a better insight into your heart function and whether you’re at higher risk of heart disease. A high score on your calcium test might influence your doctor to change your treatment plan or put you on a preventative strategy to lower the risk of heart ailments. For people who have a family history of heart disease, many agree calcium score testing is worth it to put their minds at ease and make sure there’s nothing to worry about.

What is the normal range for a CT calcium score?

Technically the best score for calcium testing is 0, as this means there is no calcified plaque within your coronary arteries. However, as we age, the majority of us will develop some plaque in the arteries. Your age will depend on how much is the normal range, so your doctor will be able to tell you the normal range for your calcium score.