Angiogram
An imaging test that shows blood vessels, using contrast dye.
What it means
An angiogram makes blood vessels visible by injecting contrast dye and imaging it as it flows. From the Greek angeion, vessel.
Two broad approaches:
- CT angiogram — dye through a vein in the arm, then a CT scan. Non-invasive, quick, used to look for pulmonary embolism and increasingly as the first test for chest pain.
- Catheter angiogram — a fine catheter threaded from the wrist or groin to the vessel itself. More invasive, but allows treatment in the same sitting.
A coronary angiogram remains the definitive way to see narrowing in the heart arteries, and stents can be placed during it.
In practice
Narrowings are reported as a percentage — a "70% stenosis" of a named artery.
Contrast dye can affect kidney function, so kidney tests are checked beforehand and metformin is sometimes paused around the procedure.
Why it matters
CT coronary angiography is now the recommended first investigation for stable chest pain of possible cardiac origin in NICE guidance, ahead of exercise testing.
An angiogram is an investigation for chest pain that has already been assessed — not something to arrange while pain is ongoing. Ongoing chest pain means 999.
Clinically reviewed by Dr Mohammad Zubair Khan, GMC 7563469
Last reviewed
August 30, 2026