CCTA vs calcium score

Both tests use a CT scanner on the heart. They answer different questions. One is not a “better version” of the other. Talk with your doctor about which test, if either, fits your situation. This page is educational — not medical advice.

Two tests, two questions

A coronary artery calcium score (CAC, sometimes called a “heart scan”) looks for calcium in the walls of the coronary arteries. Calcium there is a sign of plaque that has hardened. The test is usually done without IV contrast. Many people have it as a risk check when they feel well.

A coronary CT angiogram (CCTA) also uses a CT scanner, but IV contrast is given so the inside of the arteries can be seen. The pictures can show narrowing and plaque that is not only calcium — including softer plaque. CCTA is often used when someone has chest pain or another symptom, or when a clinician needs a clearer anatomic look than a stress test can give.

What each test can and cannot show

A calcium score does not show whether an artery is blocked today. A score of zero means little or no hardened plaque was seen. It does not prove there is no soft plaque, and it does not replace a workup if you have symptoms. A high score means there is calcified plaque and higher long-term risk. It still does not, by itself, say you need a stent.

CCTA can show the artery opening (the lumen) and plaque in the wall. It still is not a treatment. It does not place a stent. If a severe narrowing is found, your clinicians may talk about medicines, more tests, or a catheter angiogram (cath). That decision is individual.

People sometimes hear “I already had a heart CT” and assume they had a CCTA. Ask which test was done. The presence or absence of an IV, the words on the report (Agatston score versus stenosis and CAD-RADS), and the CPT code on the bill are clues. CCTA is commonly CPT 75574. A calcium score uses a different code.

Contrast, radiation, and an order

CCTA uses iodinated contrast. People with kidney disease, a contrast allergy, or certain medicines need a plan from their clinician. A calcium score usually skips that dye. Both tests use X-rays. Doses vary by scanner and protocol; ask the imaging center if you want a number for their machine.

Most CCTA exams require a physician order. A calcium score is sometimes offered as a self-pay screening, depending on the center and state rules. This directory does not treat CCTA as a walk-in screening and does not advertise “no order needed.” Read Do I need an order? if that is your question.

Where guidelines fit — in plain language

The 2021 AHA/ACC chest pain guideline gives CCTA a Class 1 recommendation in selected people with acute or stable chest pain when the clinician is evaluating possible coronary disease and the test is a good fit. That is a guideline for clinicians, not a rule that everyone with chest pain must get a CCTA. Your age, symptoms, other test results, and the quality of the local scanner all matter.

Class 1 means the writing committee judged the benefit to outweigh the risk for those selected patients. It is not a diagnosis, and it is not permission to skip talking with your own doctor.

Calcium scoring has a different job in prevention guidelines: helping estimate long-term risk in some people who do not have known coronary disease, so that a clinician can talk about statins and lifestyle. That is not the same indication as a CCTA for symptoms.

AI plaque software is a separate layer

Some centers add software (for example plaque analysis or FFR-CT) after the CCTA pictures are taken. Those tools are not the same as the scan itself. CPT 75577 (as of 2026-01-01) is the Category I code path often discussed for AI plaque analysis — it is not the 2024 CCTA code (75574) in our Medicare seed file. On this site, AI plaque and FFR-CT are listed as Unknown unless a center tells us. Unknown is not “no.” See Insurance, Medicare, and CPT 75577.

How to use this when you talk with your doctor

• If you feel well and want a risk check, ask whether a calcium score, a lipid plan, or something else is the next step.
• If you have chest pain, shortness of breath, or a confusing stress test, ask whether CCTA, another stress test, or a cath is being considered — and why.
• If a CCTA is ordered, ask how to prepare, whether beta blockers or nitroglycerin are used, and how you will get the report.
• Bring the order. Imaging centers on this list billed CCTA to Medicare; they still need the clinical paperwork their policies require.

CCTA Scan does not decide which test you need. We list where CCTA was billed and explain the words. For a location, start with Find a CCTA or a city page such as Los Angeles or Stanford.

This article is educational and is not medical advice. Medicare volume on listing pages is fee-for-service only.