Radiology• Updated 21 October 2026
CT Angiography
A CT scan with dye that shows blood vessels in detail, such as in the heart, brain, lungs or legs.
Results: 1–2 days
Quick Summary
Primary Purpose
To look for narrowed arteries, clots in the lungs, aneurysms and bleeding.
What It Measures
Blood vessels and blood flow.
Preparation
Fast for a few hours; kidney tests and allergy checks for dye.
Overview
CT pulmonary angiography is the main test for pulmonary embolism.
CT coronary angiography can check heart arteries without a catheter.
What It Measures
Arteries
Narrowing and blockages.
Clots
In the lungs.
How It's Performed
- 01
Cannula
For dye injection.
- 02
Scan
Lie still; dye may feel warm.
- 03
Afterwards
Drink plenty of water.
Sources and further reading
Last updated 21 October 2026. For more detail, see these trusted health organisations.
- CT Scans(opens in a new tab) · MedlinePlus, US National Library of Medicine
- Angiography(opens in a new tab) · NHS