What is a CT Calcium Score?
A CT Calcium Score, also known as CT Coronary Artery Calcium Score, is a non-invasive technique which measures the amount of calcium in the walls of the arteries that supply the heart muscle. The accumulation of calcium results in an increase in the hardness of the artery wall (called atherosclerosis). The more calcium there is, the higher risk of heart attack or stroke.
Unlike a CT coronary angiogram which is a diagnostic tool, this is a screening test for individuals without signs or symptoms of heart disease. This test makes it possible if you are low, normal or high-risk of having a heart attack or stroke in the next 5 – 10 years.
How is Coronary Calcium Score Measured?
A CT Calcium Score is a relatively a quick test, taking only a few minutes to complete. You will lie on the CT scanner table. A clinic nurse or radiographer will place ECG-leads on your chest, which helps with the timing of the imaging, also called “gating”. The scanner table will be positioned into the CT tube, which is also called the “donut”. Once the scan commences, you will be asked to hold your breath during the image acquisition for clear images. The total breath hold takes approximately ten (10) seconds.
Once the scan is completed, the radiographer will use special processing software to quantify and scores your relative risk compared to a normalised population for gender and age (using the Agatston method).
The table below breaks down Calcium Score, and relative risk of heart attack in the next 10 years.
| Calcium Score | Description | Risk of heart attack in 10 years |
| 0 | No calcium detected | <1%, Very low risk |
| 1 – 100 | Small amount of calcified plaque | <10%, Low risk |
| 101 – 400 | Moderate amount of plaque | 10 – 20%, Moderate Risk |
| 101 – 400 (and >75th percentile) | Moderate amount of plaque and scoring higher than 75% of individuals for age, gender and ethnicity | 15 – 20%, Moderately High Risk |
| Greater than 400 | Extensive calcified plaque | Greater than 20%, high risk |
Table adapted from Chua, Blankstein, Ko. 2020. Coronary artery calcium in primary prevention. doi: 10.31128/AJGP-03-20-5277
Does CT Calcium Score use Contrast?
No, CT calcium score is performed without IV contrast. If your CT Calcium Score is positive (< 1), you may be recommended to undergo a diagnostic test known as CT Coronary Angiography which uses IV contrast to evaluate the degree of blockage in your heart’s arteries.
Why Calcium Score Matters?
By understanding your risk level, it allows your doctor to provide early advice on personalised lifestyle changes which may reduce your risk of having a heart attack or stroke.
While medication is necessary and important, many individuals seek the valuable opportunity make lifestyle changes to avoid or delay the initiation of medication such as statins.
Who Should Consider a Calcium Score?
A CT Coronary Calcium Score may be recommended if, based on other non-imaging predictive factors such as blood pressure, cholesterol levels, smoking status, an individual is considered at moderate risk, or low risk with risk enhancing factors. You can read the Australian Heart Foundation’s Position Statement here.
This may include individuals whose risk is likely to be underestimated by traditional calculators including:
- Strong family history of premature heart disease. Risk calculators such as Framingham and Australian CVD calculator don’t always capture family history well.
- Metabolic risk factors such as elevated BMI, abdominal obesity, pre-diabetes. These are not always weighted strongly if in normal range.
- Visceral adipose tissue (fat around abdominal organs) is now recognised to be a superior marker to adiposity compared to waist circumference and BMI.
- High proportion of visceral fat is associated with higher-risk of coronary artery disease and stroke, metabolic syndrome, and chronic inflammation. Whole Body MRI™ packages includes a research-grade DEXA body composition for quantification of visceral fat for superior understanding of adiposity-related risk factors.
- Known elevated lipoprotein(a) and other emerging blood-based biomarkers that are not incorporated in standard calculators.
- Women
- Standard calculators sometimes underestimate women’s risk, especially younger women with non-traditional risk factors such as autoimmune diseases, history of pre-eclampsia, early menopause.
- Interestingly, once thought to be a localised disease, endometriosis is increasingly recognised to be a systemic inflammatory condition that is associated with a small, but measurable, increase risk of cardiovascular disease (CVD).
- Sleep apnoea is not a traditional risk factor; however, is known to be independently associated with higher risk of hypertension, CVD, and heart failure.
- Lifestyle or environmental factors such as heavy long-term smokers who are still relatively young, people with chronic kidney disease, or chronic inflammatory disease such a rheumatoid arthritis.
Because a CT coronary calcium score is a screening test, it is not recommended for individuals who are known to have high-risk for coronary artery disease, have been diagnosed with heart disease, or are symptomatic. These individuals are best assessed with a diagnostic tool, known as CT coronary angiography (CTCA).
All Whole Body MRI™ Screening Packages Include a CT Calcium Score
Our goal is to provide you with the most comprehensive, proactive insights into your health – a journey into the known.
A whole-body screening approach would be incomplete without considering heart disease risk in people who may have no symptoms. Cardiovascular disease is the leading cause of death in Australia, responsible for 1 in 4 deaths each year. In fact, around 25%, or even as many as 45%, of heart attacks are “silent” or happen without the classic symptoms. This is especially common in women, making prevention and early detection even more critical.
The good news: heart disease is largely preventable, thanks to many modifiable risk factors. Understanding your risk helps individuals take preventative action.
That is why we include CT coronary calcium scoring in all of our screening packages. Evidence-based studies consistently show that CT calcium scoring is one of the strongest predictors of a future heart attack. When combined with other advanced health markers, such as visceral adipose tissue and lipoprotein(a), the picture becomes even more precise.
Our Executive Package goes one-step further by including 10+ additional dedicated diagnostic imaging tests – including a carotid Doppler ultrasound for functional evaluation of blood flow velocity to detect any narrowing of the main artery to your brain. Carotid plaque is strongly correlated with plaque elsewhere in the body, and unlike CT calcium scoring, can detect clinically important narrowing. Although not recognised as a general screening tool, this scan offers an added layer of insight for those wanting the most comprehensive view of cardiovascular health.
More information or ready to book?
Contact us, or our Partner Clinic, if you would like more information about our Whole-body Screening Packages, Technology, or what conditions can be detected.
If you are interested in a CT Coronary Calcium Score, but are not yet ready to book a Whole Body MRI screening Package, our Partner Clinic MBR Health offers SPECTRAL CT Coronary Calcium Scores for a small out of pocket fee.
Ready to book? Contact us to begin your journey into the known.