CT Scan
A scan that uses X-rays and a computer to create detailed cross-section images of the body.
Quick Summary
To look at the brain, chest, tummy and bones in detail, for example after injury, stroke or for cancer.
Detailed images of organs, blood vessels and bones.
You may need to fast and have a dye (contrast) injection. Tell staff about kidney problems, allergies, diabetes medicines and pregnancy.
Overview
CT gives much more detail than a plain X-ray and is quick, which makes it useful in emergencies.
It uses more radiation than an X-ray, so it's done when the benefit is clear.
What It Measures
Organs
Brain, lungs, liver, kidneys and bowel.
Blood vessels
With contrast dye (CT angiography).
How It's Performed
- 01
Preparation
Change into a gown; a cannula may be placed for dye.
- 02
Scan
Lie still on a table that moves through a ring-shaped scanner; it takes a few minutes.
- 03
Afterwards
Drink plenty of water if dye was used.
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
- CT scan(opens in a new tab) · NHS