Quick answer
Coronary CT (cardiac or coronary CT scan) shows the arteries of the heart without a probe or catheter. It is a non-invasive examination that allows coronary artery disease to be screened for or assessed accurately, after specific preparation (heart rate, fasting).
🫀 What is it?
Coronary CT, also called cardiac CT or coronary CT angiography, shows the coronary arteries (the arteries of the heart) without a probe or catheter. As a non-invasive examination, it allows coronary artery disease to be screened for or assessed accurately. Specific preparation is needed to slow the heart.
📋 How to prepare
Fast for 4 hours before the examination.
Avoid caffeine (coffee, tea, energy drinks) for 12 hours beforehand.
If your heart rate is above 65 bpm, a beta-blocker will be prescribed: take it the day before and on the morning of the examination according to the instructions.
Bring your recent ECG if available, and the list of your medications.
Tell us about any allergy to iodinated contrast medium.
▶️ How does it go?
A continuous ECG is recorded during the acquisition.
A venous catheter is placed in your arm for the injection of contrast medium.
Sublingual nitroglycerin spray may be given to dilate the coronary arteries.
The acquisition lasts only a few seconds. A short breath-hold is requested. You will feel a sensation of warmth during the injection.
✅ After the examination
You can resume your activities immediately.
Drink plenty of fluids to eliminate the contrast medium.
The report is sent to your cardiologist within 2 to 5 working days.
❓ Frequently asked questions
What is a coronary CT?
Do I need to fast for a coronary CT?
Is a beta-blocker always necessary?
✓ Why you can trust this page
Written by the Radiology team at Cochin Hospital AP-HP, Paris Cité University. Medical review by a radiologist of the department. Last updated: July 2026.