Coronary Artery Calcium Scoring Uses CT Scanning Technology
Yes, a coronary artery calcium (CAC) score is performed using a computed tomography (CT) scan. The CAC score specifically uses a non-contrast CT scan of the heart to quantify calcium deposits in the coronary arteries 1.
Technical Details of CAC Scoring
CAC scoring involves the following CT-based components:
- Non-contrast CT scan: CAC scoring is performed using a non-contrast CT scan specifically targeting the heart 1
- ECG-gating: Ideally, the scan is ECG-gated (synchronized with the heartbeat) to minimize motion artifacts, though non-gated chest CTs can also be used for CAC assessment 1, 2
- Agatston scoring method: The most common quantification method uses the Agatston score, which calculates calcium burden based on the density and area of calcified lesions 1
- Visual assessment alternative: When Agatston scoring software isn't available, visual assessment (none, mild, moderate, or heavy/severe) can be used 1
Clinical Applications
CAC scoring via CT is primarily recommended for:
- Asymptomatic adults aged 40-75 years with intermediate cardiovascular risk (10-20% 10-year ASCVD risk) 3
- Borderline risk patients (5-10% 10-year risk) with uncertainty about statin therapy 3
- Low risk patients with concerning features like strong family history of premature ASCVD 3
Interpretation of Results
The CT-derived CAC scores correlate with cardiovascular risk:
- CAC score of 0: Low risk (<1% annual event rate) 3
- CAC score of 1-99: Moderate risk 3
- CAC score of ≥100: High risk 3
- CAC score of >400: Very high risk 3
Important Distinctions
- CAC scoring vs. coronary CT angiography (CCTA): CAC scoring uses non-contrast CT, while CCTA requires contrast enhancement 1
- Dedicated vs. opportunistic CAC scoring: While dedicated CAC scoring is performed with ECG-gated cardiac CT, CAC can also be assessed on routine chest CTs performed for other reasons 2, 4
- Limitations: CAC scoring only detects calcified plaque and cannot detect non-calcified atherosclerotic plaque 1
Emerging Technologies
Recent advances in CAC scoring technology include:
- Automated CAC scoring using deep learning algorithms for both dedicated gated coronary CT and routine non-gated chest CTs 5
- Methods to derive CAC scores from contrast-enhanced CT scans, potentially eliminating the need for separate non-contrast scans 6, 7
It's important to note that while CAC scoring is not recommended for symptomatic patients to rule out coronary artery disease (as CACS = 0 does not exclude obstructive CAD), it remains a valuable tool for risk stratification in asymptomatic individuals 1.