MRI • CT • Sonography
Reading your calcium score
A calcium score test produces a single number — the Agatston score — and almost everything useful about the test comes down to what that number means for you. It is not a percentage, not a blockage measurement and not a pass or fail. It is a measure of how much calcified plaque has accumulated in your coronary arteries.
This page explains the score and the bands it falls into. If you have not had the test yet, CT coronary calcium score covers who it is for, and CT calcium score describes the scan itself.
What your calcium score number means
The Agatston score is calculated by software, not estimated by eye. Every area of calcification in the coronary arteries above a set density threshold is identified, its area measured, and that area multiplied by a weighting factor reflecting how dense the deposit is. Those values are summed across all the vessels to give the total.
So the score captures two things at once — how much calcium is there, and how dense it is. It is reported alongside a percentile for your age and sex, which is often the more informative figure of the two. A score of 50 places a 45-year-old well above their peer group and a 70-year-old close to the middle of theirs.
Calcium score ranges and what each one indicates
These bands are the standard framework physicians use to interpret an Agatston score. Your doctor reads them together with your age, blood pressure, lipid profile and family history — no band on its own determines treatment.
| Agatston Score | What It Indicates | Typical Clinical Response |
|---|---|---|
| 0 | No detectable calcified plaque | Low short-term risk; risk factors managed conservatively |
| 1 – 99 | Mild coronary calcification | Lifestyle measures, with medication considered on overall risk |
| 100 – 399 | Moderate plaque burden | Preventive treatment usually recommended |
| 400 and above | Extensive coronary calcification | Intensive preventive treatment and cardiology referral |
How the score guides your treatment plan
The score's practical value is that it converts an estimate into a measurement, which usually makes a borderline treatment decision straightforward in one direction or the other.
When the score is low or zero
A reassuring result can justify holding off on long-term medication.
- Supports a conservative approach where risk was borderline
- Re-assessment typically considered after about five years
When the score is raised
A measured plaque burden usually strengthens the case for treating early.
- Often prompts firmer cholesterol and blood pressure targets
- Higher bands commonly lead to a cardiology referral
Where the calcium score sits alongside other heart tests
The calcium score answers a question about long-term risk. It does not assess how well the heart muscle is pumping, how the valves are working or whether blood flow is currently restricted — each of those needs a different test.
A 2D echo test examines heart muscle function, chamber size and valve movement using ultrasound. A stress test looks for flow limitation under exertion. These are complementary to a calcium score rather than alternatives to it, and it is common for a patient to have more than one.
What your report contains
Every calcium score report issued at Imaging World includes the following, so your doctor has what they need without a follow-up request.
01
Total Agatston Score
The headline figure, summed across all coronary arteries, with the band it falls into clearly stated.
02
Per-Artery Breakdown
Separate scores for the left main, left anterior descending, circumflex and right coronary arteries, showing how the calcification is distributed.
03
Age and Sex Percentile
Where your score sits relative to others of the same age and sex — often more informative than the raw number on its own.
04
Radiologist's Interpretation
A written summary from a Consultant Radiologist, issued the same day in digital and printed form for discussion with your treating doctor.
Frequently asked questions
Zero is the only score meaning no calcified plaque was detected. Anything above zero confirms coronary atherosclerosis is present, though a low score in an older patient may still be unremarkable for their age — which is why the report includes a percentile alongside the raw number.
Generally no. Calcium deposits do not dissolve, and scores tend to rise slowly even on treatment. Statins can actually increase the measured score by stabilising soft plaque into a denser form — a favourable change despite the higher number. The score sets the intensity of treatment; it does not track its success.
Above 400 is generally treated as high risk and usually prompts intensive preventive treatment with a cardiology referral. Between 100 and 400 sits in the moderate band. No single threshold decides anything on its own — the score is read together with your age, sex, blood pressure, lipids and family history.
It means the symptoms need investigating on their own terms. A calcium score only detects calcified plaque — soft plaque and non-cardiac causes of chest discomfort are both invisible to it. A zero score is reassuring about long-term risk but never rules out a cause for current symptoms. Report ongoing chest pain to your doctor regardless.
Software identifies every area of calcification above a set density threshold, measures its area and multiplies that by a weighting factor based on density. The values are added together across all the arteries. The result reflects both how much calcium is present and how dense it is.
Yes. Our reports give the total Agatston score plus a breakdown for the left main, left anterior descending, circumflex and right coronary arteries, together with your age and sex percentile. Cardiologists often want the distribution as well as the total.