Imaging~1–2 hrs
Cardiac CT Angiography
An advanced imaging test that provides detailed 3D pictures of your heart and blood vessels to detect blockages.
Cardiac CT angiography (CTCA) uses high-resolution, ECG-gated CT with intravenous contrast to produce detailed three-dimensional images of the coronary arteries. CT-FFR extends this by assessing the functional significance of arterial narrowing without catheterisation.
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Advanced CT imaging produces detailed 3D visualizations of the coronary arteries, identifying blockages without invasive surgery.
A Look Inside the Arteries Without a Catheter
For decades, the only way to see inside the coronary arteries was an invasive angiogram — a catheter threaded up from the wrist or groin. Cardiac CT angiography now does much of the same job from the outside.
A short injection of iodine contrast lights up the arteries, and a fast, ECG-synchronised CT scanner freezes the beating heart to build a detailed three-dimensional map. It shows not just the narrowings but the plaque in the artery wall itself — including the soft, non-calcified plaque a calcium score cannot see. For stable chest pain, it is now the recommended first test in most international guidelines.
A short injection of iodine contrast lights up the arteries, and a fast, ECG-synchronised CT scanner freezes the beating heart to build a detailed three-dimensional map. It shows not just the narrowings but the plaque in the artery wall itself — including the soft, non-calcified plaque a calcium score cannot see. For stable chest pain, it is now the recommended first test in most international guidelines.
How the Scan Works
A slow heart rate gives the sharpest pictures, so you may be given a beta-blocker tablet an hour beforehand to bring the rate below about 65. A cannula goes into a vein for the contrast, and a small spray of nitrate under the tongue widens the arteries. The scan itself lasts a single breath-hold of a few seconds. Plan for one to two hours in total. Fast for four hours beforehand and avoid caffeine that day, since it works against the beta-blocker.
What the Result Tells Us (CAD-RADS)
Findings are graded on the standardised CAD-RADS scale:
- CAD-RADS 0–2 — no or minor narrowing; medication and risk-factor control, and chest pain is very unlikely to be from the heart
- CAD-RADS 3 — a 50 to 69% narrowing; a CT-FFR analysis can work out from the same scan whether it is actually limiting blood flow
- CAD-RADS 4–5 — a narrowing of 70% or more, or a blockage; usually leads on to an invasive angiogram with a view to a stent
When We Recommend One in Singapore
CT angiography is the test of choice in several common situations.
- Stable chest tightness or breathlessness where the likelihood of coronary disease is low to moderate
- An inconclusive or borderline treadmill or stress test
- New heart failure or atrial fibrillation where a coronary cause needs to be ruled out
- Assessing a known coronary anomaly or the grafts after bypass surgery
- It is less useful with a very high calcium score, an irregular fast heart rate, or significant kidney impairment; privately in Singapore it costs roughly SGD 800 to SGD 1,500
After the Scan
A radiologist and Dr. Chang review the images together. A normal CT angiogram is one of the most powerful reassurances in cardiology — it makes significant coronary disease very unlikely for years to come. Where disease is found, the scan guides the next step precisely: intensifying medication for mild or moderate disease, or proceeding to an invasive angiogram and stent for a tight, flow-limiting narrowing. The soft-plaque information also sharpens how aggressively we treat cholesterol.
Cardiac CT Angiography: Common Questions
Ready to Schedule Your Cardiac CT Angiography?
Most evaluations are available on the same day as your consultation with Dr. Peter Chang at Paragon Medical Centre, Singapore.