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CT scan

A CT scan uses X-rays and computer calculations to create detailed cross-sectional images of the body. Contrast medium is sometimes needed to show organs and blood vessels more clearly. Report pregnancy, kidney problems, allergic reactions, diabetes medicines and all other medicines beforehand.

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  • CT stands for computed tomography. The examination uses X-rays to make detailed images in thin slices.
  • The scan itself is usually painless. You lie on a table that slides through a wide, short ring.
  • Contrast medium is sometimes needed. It may be given through a drip, as a drink or through a body opening, depending on the question being investigated.
  • Before the scan, report possible pregnancy, kidney problems, previous contrast reactions, thyroid disease, diabetes and all medicines.
  • The radiation dose is kept as low as reasonably possible while providing sufficient image quality. The benefit of a necessary scan generally outweighs the small risk.
  • Always follow your personal appointment confirmation; preparation varies by body part and reason for examination.

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Further reading

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U
Ultrasound scanAn ultrasound scan creates images using sound waves. It can assess organs, blood flow, pregnancy and superficial tissues without X-rays. The preparation needed and what a result means depend on the type of scan and the medical question.
M
MRI scanMRI uses a strong magnet and radio waves to make detailed images without X-rays. A complete safety check for metal, implants, gas cylinders and pregnancy is essential.
P
Pregnancy and contrast agentsContrast agents can make organs and blood vessels clearer on CT, MRI or fluoroscopy. Iodinated contrast, and especially gadolinium, are used during pregnancy only when expected medical benefit outweighs possible risks. A necessary scan for a serious condition must not be delayed dangerously.