Looking at the coronary arteries without a catheter
Coronary computed tomography angiography (CCTA) uses ECG-synchronised CT imaging and intravenous iodinated contrast to visualise the coronary artery lumen and wall. It can identify atherosclerotic plaques, including non-obstructive disease, and assess narrowing. Its usefulness depends on the clinical question and image quality.
When is it appropriate?
CCTA can help evaluate selected patients with stable chest discomfort and suspected coronary disease. It is not a universal screening test for people without symptoms. Acute symptoms require a separate risk-based pathway: a suspected high-risk heart attack must not be delayed to arrange a CT scan.1
What happens during the examination?
The team reviews heart rhythm and rate, kidney function, previous contrast reactions and relevant conditions. Medicines to slow the heart or dilate the coronary arteries may be used when appropriate. You need to lie still and briefly hold your breath. Radiation exposure varies with the equipment, protocol and patient; it is not zero.
What does a plaque mean?
A plaque does not necessarily cause a flow-limiting narrowing. Intermediate lesions may need functional imaging or other assessment to establish whether they cause ischaemia. A CT finding alone does not automatically justify a stent: symptoms, anatomy, functional significance and the overall clinical picture guide decisions.1
CCTA and calcium scoring answer different questions
Coronary calcium scoring normally uses CT without contrast to quantify calcified plaque and refine risk assessment in selected people. CCTA uses contrast to assess coronary anatomy, including non-calcified plaque. A calcium score of zero does not exclude every form of coronary disease, particularly in a symptomatic person.2
Limitations and precautions
Extensive calcification, irregular or fast heart rhythms, body size and difficulty holding the breath may affect image quality. Kidney impairment and previous contrast reactions require individual assessment. Tell the team about possible pregnancy and all medicines you take. Follow the imaging centre’s preparation instructions; do not change medication independently.3
Choosing the right next question
For background on what the scan investigates, read coronary artery disease. To understand prevention and risk assessment, explore SCORE2 and hypertension.
About Massimo Fioranelli · Cardiology and internal medicine · Clinical practice at Sanatrix, Rome
References and further reading
- ESC 2024: chronic coronary syndromes.
- ACR/RSNA RadiologyInfo: cardiac CT for calcium scoring.
- ACR/RSNA RadiologyInfo: coronary CTA.
Coronary artery disease · Cardiovascular risk · Italian version
Reviewed 23 October 2026. Educational information does not replace individual medical assessment.